Medtronic 7299 Reference Guide

INSYNC SENTRY®7299

Dual chamber implantable cardioverter deﬁbrillator with cardiac resynchronization therapy including sequential biventricular pacing and OptiVol®Fluid Monitoring

Reference Manual

Caution: Federal Law (USA) restricts this device to sale by or on the order of a physician.

INSYNC SENTRY®7299

Reference Manual

A guide to the operation and programming of the Model 7299 InSync Sentry dual chamber implantable cardioverter deﬁbrillator with cardiac resynchronization therapy including sequential biventricular pacing and OptiVol

Fluid Monitoring

The following are trademarks of Medtronic:

Active Can, Cardiac Compass, Checklist, Flashback, InSync, InSync II Marquis, InSync Maximo, InSync Sentry, Leadless, Marker Channel, Marquis, Maximo, Medtronic, Medtronic CareLink, OptiVol, PR Logic, Patient Alert, Quick Look, QuickLink, T-Shock

Introduction 11

Part I Quick overview 13

1 Quick reference 15

1.1 Physical characteristics 17

1.2 Magnet application 18

1.3 Projected longevity 19

1.4 Replacement indicators 21

1.5 Typical charge times 21

1.6 High-voltage therapy energy 22

1.7 Stored data and diagnostics 23

1.8 New and enhanced features 24

2 The InSync Sentry system 27

2.1 System overview 29

2.2 Indications and usage 33

2.3 Contraindications 33

2.4 Patient screening 33

3 Emergency therapy 35

3.1 Delivering emergency therapies 37

3.2 Delivering an emergency deﬁbrillation therapy 38

3.3 Delivering an emergency cardioversion therapy 39

3.4 Delivering emergency ﬁxed burst pacing 39

3.5 Enabling emergency VVI pacing 40

Part II Device implant and patient follow-up

procedures 43

4 Implanting the device 45

4.1 Implant overview 47

4.2 Preparing for an implant 47

4.3 Replacing a device 49

4.4 Surgical approach 50

4.5 Sensing and pacing measurements 54

4.6 Connecting the leads to the device 54

INSYNC SENTRY®7299 Reference Manual

Contents

4.7 Testing deﬁbrillation operation and effectiveness 58

4.8 Positioning and securing the device 61

4.9 Completing the implant procedure 61

5 Conducting a patient follow-up session 63

5.1 Patient follow-up guidelines 65

5.2 Verifying the status of the implanted system 65

5.3 Verifying effective cardiac resynchronization therapy 66

5.4 Verifying effective basic pacing 67

5.5 Verifying accurate detection and appropriate therapy for ventricular tachyarrhythmias 68

Part III Conﬁguring the device for the patient 71

6 Detecting tachyarrhythmias 73

6.1 Detection overview 75

6.2 Setting up sensing 78

6.3 Detecting VF episodes 83

6.4 Detecting VT episodes 86

6.5 Detecting FVT episodes 92

6.6 Detecting tachyarrhythmia episodes with Combined Count 97

6.7 Monitoring episodes for termination or redetection 99

6.8 Enhancing detection with PR Logic criteria 103

6.9 Enhancing VT detection with the Stability criterion 111

6.10 Detecting double tachycardias 113

6.11 Detecting prolonged tachyarrhythmias with High Rate Timeout 114

7 Treating tachyarrhythmia episodes 117

7.1 Treating VF with deﬁbrillation 119

7.2 Treating VT and FVT with antitachycardia pacing 128

7.3 Treating VT and FVT with cardioversion 137

7.4 Optimizing therapy with Smart Mode and Progressive Episode Therapies 146

8 Treating ventricular dyssynchrony and

bradycardia 151

8.1 Providing basic pacing therapy 153

INSYNC SENTRY®7299 Reference Manual

Contents

8.2 Dual chamber pacing 161

8.3 Single chamber pacing 172

8.4 Promoting continuous CRT delivery 176

8.5 Rate adjustments to optimize cardiac output 186

8.6 Managing atrial tracking to optimize A-V synchrony 198

8.7 Providing Ventricular Safety Pacing 210

9 Optimizing charge time and device longevity 215

9.1 Optimizing charge time 217

9.2 Optimizing device longevity 219

Part IV Evaluating and managing patient treatment 221

10 Using the programmer 223

10.1 Setting up and using the programmer 225

10.2 Display screen features 226

10.3 Viewing and programming device parameters 231

10.4 Starting and ending patient sessions 235

10.5 Viewing live waveform traces 238

10.6 Recording live waveform strips 245

10.7 Transferring, saving, and retrieving device data 247

10.8 Printing reports 255

11 Using system evaluation tools 261

11.1 A summary of system evaluation tools 263

11.2 Taking a quick look at device activity 264

11.3 Using the Patient Alert feature 265

11.4 Streamlining follow-ups with Checklist 273

12 Setting up and viewing collected data 277

12.1 A summary of data collection 279

12.2 Viewing battery and lead status data 280

12.3 Printing rate histograms 286

12.4 Viewing the Heart Failure Management report 289

12.5 Viewing clinical trends in the Cardiac Compass report 293

12.6 Viewing the episode and therapy efﬁcacy counters 302

12.7 Viewing episode data 305

12.8 Viewing Flashback Memory 314

12.9 Setting up data collection 316

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Contents

12.10 Viewing and entering patient information 322

12.11 Automatic device status monitoring 325

13 Testing the system 329

13.1 Testing overview 331

13.2 Evaluating the underlying rhythm 331

13.3 Measuring pacing thresholds 332

13.4 Measuring lead impedance 335

13.5 Measuring EGM amplitude 337

13.6 Testing the device capacitors 339

14 Conducting Electrophysiologic Studies 341

14.1 EP Study overview 343

14.2 Inducing VF with T-Shock 344

14.3 Inducing VF with 50 Hz Burst 348

14.4 Inducing an arrhythmia with Manual Burst 350

14.5 Inducing an arrhythmia with PES 352

14.6 Delivering a manual therapy 355

15 Solving system problems 359

15.1 Overview 361

15.2 Solving cardiac resynchronization therapy problems 361

15.3 Solving sensing problems 362

15.4 Solving tachyarrhythmia detection problems 364

15.5 Solving tachyarrhythmia therapy problems 365

15.6 Solving bradycardia pacing problems 366

15.7 Responding to device status indicators 367

Appendices 369

A Warnings and precautions 371

A.1 General warnings 373 A.2 Handling and storage instructions 373 A.3 Device operation 374 A.4 Lead evaluation and lead connection 376 A.5 Follow-up testing 378 A.6 Explant and disposal 378 A.7 Medical therapy hazards 378 A.8 Home and occupational environments 381

B Device parameters 383

B.1 Emergency settings 385

INSYNC SENTRY®7299 Reference Manual

C Device programming recommendations 403

Glossary 411

Index 419

Contents

B.2 Detection parameters 386 B.3 Therapy parameters 387 B.4 Pacing parameters 389 B.5 System maintenance parameters 392 B.6 Data collection parameters 394 B.7 System test and EP study parameters 395 B.8 Fixed parameters 398

B.9 Patient information parameters 399 B.10 Programmer symbols 400 B.11 Parameter interlocks 402

C.1 Device programming recommendations 405

C.2 V-V Delay programming recommendations 407

INSYNC SENTRY®7299 Reference Manual

Introduction

Using this manual

Before implanting the device, it is strongly recommended that you:

Manual conventions

Throughout this document, the word “device” refers to the implanted InSync Sentry device.

Introduction

Refer to the product literature packaged with the device for

•

information about prescribing the device.

Thoroughly read this manual and the technical manuals for

•

the leads and the implant tools used with the device.

Discuss the procedure and the device system with the

•

patient and any other interested parties, and provide them

with any patient information packaged with the device.

Technical support

References

The nominal value for that parameter.

On-screen buttons are shown with the name of the button surrounded by brackets: [Button Name].

Medtronic employs highly trained representatives and engineers located throughout the world to serve you and, upon request, to provide training to qualiﬁed hospital personnel in the use of Medtronic products.

In addition, Medtronic maintains a professional staff of consultants to provide technical consultation to product users.

For more information, contact your local Medtronic representative, or call or write Medtronic at the appropriate address or telephone number listed on the back cover.

The primary reference for background information is Zacouto FI, Guize LJ. Fundamentals of Orthorhythmic Pacing. In: Luderitz B, ed. Springer-Verlag; 1976: 212-218.

symbol in parameter tables indicates the Medtronic

Cardiac Pacing Diagnostic and Therapeutic Tools. New York:

INSYNC SENTRY®7299 Reference Manual

Introduction

Notice

See these additional references for more background information:

Estes M, Manolis AS, Wang P, Eds.

•

Cardioverter-Deﬁbrillators

Inc. 1994.

Kroll MW, Lehmann MH, Eds.

•

Cardioverter-Deﬁbrillator Therapy: The Engineering-Clinical Interface

Singer I, Ed.

•

NY: Futura Publishing Co. 1994.

Singer I, Barold SS, Camm AJ, Eds.

•

Therapy of Arrhythmias for the 21st Century: The State of the Art

Software is provided as an informational tool for the end user. The user is responsible for accurate input of patient information into the software. Medtronic makes no representation as to the accuracy or completeness of the data input into the software. Medtronic SHALL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES TO ANY THIRD PARTY WHICH RESULT FROM THE USE OF THE INFORMATION PROVIDED IN THE SOFTWARE.

. Norwell, MA: Kluwer Academic Publishers 1996.

Implantable Cardioverter-Deﬁbrillator. Armonk,

. Armonk, NY: Futura Publishing Co. 1998.

. New York, NY: Marcel Dekker,

Implantable

Nonpharmacological

INSYNC SENTRY®7299 Reference Manual

Quick overview

Part I

1Quick reference

1.1 Physical characteristics 17

1.2 Magnet application 18

1.3 Projected longevity 19

1.4 Replacement indicators 21

1.5 Typical charge times 21

1.6 High-voltage therapy energy 22

1.7 Stored data and diagnostics 23

1.8 New and enhanced features 24

1.1 Physical characteristics

Table 1. Device physical characteristics

Volume

Mass

H x W x D

Surface area of device can

Radiopaque ID

Materials in contact with human tissue

Battery Lithium silver vanadium oxide

Connectors Two IS-1 connectors for pacing and

Measurements are nominal values based on CAD (computer aided design) model measurements and are rounded to the nearest unit.

Volume with connector holes unplugged.

Grommets may protrude slightly beyond the can surface.

Engineering series number follows the radiopaque code.

These materials have been successfully tested and veriﬁed for biocompatibility. The device does not produce an injurious temperature in the surrounding tissue.

1Quick reference

Physical characteristics

3 b

40 cm

78 g

73 mm x 51 mm x 15 mm

67 cm

PRK

Titanium / polyurethane /silicone rubber / silicone adhesive

sensing, one IS-1 connector for pacing, two DF-1 connectors for high-voltage therapy, Active Can electrode (programmable)

Table 2. Lead connections

Device port Connector type Software name

SVC (HVX) DF-1 SVC

RV (HVB) DF-1 RVcoil

Can

—

Can

RV IS-1 bipolar RVtip and RVring

LV IS-1 bipolar LVtip and LVring

A IS-1 bipolar Atip and Aring

INSYNC SENTRY®7299 Reference Manual

Chapter 1

Magnet application

Figure 1. Lead connections

1 SVC (HVX) 2 RV (HVB) 3 Can (HVA) 4 LV 5 RV 6 A

Figure 2. Suture holes

1.2 Magnet application

Bringing a magnet close to the device triggers changes in device operation as shown in Table 3. When the magnet is removed, the device returns to its programmed operations.

For information on demonstrating Patient Alert tones to the patient, see Section 11.3.4, “Instructing the patient”, page 271.

INSYNC SENTRY®7299 Reference Manual

Table 3. Effects of magnet application on the device

Pacing mode as programmed

Pacing rate and interval as programmed

VF, VT, and FVT detection suspended

Patient Alert audible tones (20 s or less)

Rate response adjustments are suspended while a Patient Alert tone sounds.

Detection resumes if telemetry is established and the application software is running, or detection resumes after the application software has started.

Or “VF Detection/Therapy Off” is the only alert enabled.

1.3 Projected longevity

Longevity estimates are based on accelerated battery discharge data and device modeling with EGM pre-storage off (see Table 4). The following table displays projected longevity in years with pacing outputs programmed to the speciﬁed amplitude and 0.4 ms pulse width, DDD mode, 100% biventricular pacing, speciﬁed percentage of atrial pacing at 60 ppm with the remainder at 70 ppm atrial tracking, and semiannual full-energy charges.

1Quick reference

Projected longevity

high/low dual tone (high urgency

•

alert occurred) on/off intermittent tone (lower

•

urgency alert occurred) continuous test tone (no alert

•

occurred) no tone (alerts are disabled)

•

Table 4. Projected longevity in years

Amplitudes: A/RV; LV

2.5 V; 3.0 V

% atrial pacing

pacing impedance

0% 5.8 6.2 6.5

500 Ù

700 Ù pacing impedance

900 Ù pacing impedance

25% 5.6 6.0 6.4

50%

100% 5.2

3.0 V; 4.0 V

Semiannual full-energy charges may include therapy shocks or capacitor formations. Additional full-energy charges due to therapy shocks, device testing, or capacitor formation reduces device longevity by approximately 26 days (0.07 years). Additional 30 J charges due to therapy shocks or device testing reduces device longevity by approximately 22 days (0.06 years).

0% 4.9

5.5

6.0 6.3

5.7

5.5

INSYNC SENTRY®7299 Reference Manual

6.1

5.8

Chapter 1

Projected longevity

Table 4. Projected longevity in years (continued)

Amplitudes: A/RV; LV

The longevity of the ICD is dependent on several factors. The following factors result in decreased longevity:

an increase in pacing rate, pacing amplitude, or pulse

•

width; the ratio of paced to sensed events; or the charging frequency

a decrease in pacing impedance

•

using the pre-onset EGM storage feature or Holter telemetry

•

Considerations for using EGM pre-storage – When the EGM pre-storage feature is programmed to Off, the device starts to store EGM following the third tachyarrhythmia event and also provides up to 20 s of information before the onset of the tachyarrhythmia, including this information:

AA and VV intervals

•

Marker Channel

•

Interval Plot Flashback

•

% atrial pacing

25% 4.8 5.3

50% 4.6 5.2 5.6

100% 4.4 5.0 5.4

500 Ù pacing impedance

700 Ù pacing impedance

900 Ù pacing impedance

5.7

When the EGM pre-storage feature is programmed to On, the device also collects up to 20 s of EGM information before the onset of the arrhythmia.

In a patient who uniformly repeats the same onset mechanisms, the greatest clinical beneﬁt of pre-onset EGM storage is achieved after a few episodes are captured. To maximize the effectiveness of the EGM pre-storage feature and optimize device longevity, consider these programming options:

Turn pre-storage to On to capture possible changes in the

•

onset mechanism following signiﬁcant clinical adjustments, for example, device implant, medication changes, and surgical procedures.

Turn pre-storage to Off once you have successfully captured

•

the information of interest.

INSYNC SENTRY®7299 Reference Manual

1.4 Replacement indicators

Battery voltage and messages about replacement status appear on the programmer display and on printed reports. The Elective Replacement Indicator (ERI) and the End of Life (EOL) conditions are listed in Table 5.

Table 5. Replacement indicators

Elective Replacement (ERI) ≤ 2.62 V

End of Life (EOL) 3 months after ERI

ERI date – The Quick Look and Battery and Lead Measurements screens display the date when the battery reached ERI.

Temporary voltage decrease – The battery voltage temporarily decreases following a high-voltage charge. If a battery measurement is taken immediately after a high-voltage charge, the ERI or EOL indicator may be displayed. However, this is a temporary status that will return to normal when the battery has recovered from the charge.

EOL indication – If the programmer indicates that the device is at EOL, replace the device immediately.

1Quick reference

Replacement indicators

Post-ERI conditions – EOL device status is deﬁned as 3 months following an ERI indication assuming the following post-ERI conditions: 0% DDD atrial pacing; 100% DDD RV and LV pacing at 60 ppm; 3 V atrial and RV pacing amplitude; 4 V LV pacing amplitude; 0.4 ms pulse width; 500 Ù pacing load; and six 35 J charges. EOL may be indicated before the end of 3 months if the device exceeds these conditions.

1.5 Typical charge times

The most recent capacitor charge time appears on the programmer display and on printed reports and can be evaluated using the Charge/Dump test (see Table 6).

Table 6. Typical

At Beginning of Life (BOL)

At Elective Replacement (ERI)

These charge times are typical when the capacitors are fully formed.

full-energy charge times

7.1 s

9.0 s

INSYNC SENTRY®7299 Reference Manual

Chapter 1

High-voltage therapy energy

1.6 High-voltage therapy energy

The stored energy of the device is derived from the peak capacitor voltage and is always greater than the energy delivered by the device. Table 7 compares the programmed energy levels delivered by the device to the energy levels stored in the capacitors before delivery.

Table 7. Comparison of delivered (programmed) and stored energy levels

Energy ( J) Energy ( J)

Delivered Programmed Stored

Energy delivered at connector block into a 75 Ù load.

Energy stored at end of charge on capacitor.

Typical charge time at Beginning of Life (BOL) with fully formed capacitors, rounded to the nearest tenth of

a second.

Charge Timec( s)

Delivereda/ Programmed Stored

35 39 7.1 10 12 2.0

32 37 6.5 9 10.5 1.8

30 34 6.1 8 9.3 1.6

28 32

5.7 7

8.2 1.4

26 30 5.2 6 7.1 1.2

25 29 5.0

5.9 1.0

24 27 4.8 4 4.8 0.8

22 25 4.4 3 3.6 0.6

20 23 4.0 2 2.4 0.4

18 21 3.6 1.8 2.2 0.4

16 19 3.2 1.6 2.0 0.3

15 17 3.0 1.4 1.7 0.3

14 16 2.8 1.2 1.5 0.2

13 15 2.6 1.0 1.2 0.2

12 14 2.4 0.8 1.0 0.2

11 13 2.2 0.6 0.8 0.1

0.4 0.5 0.1

Charge Timec( s)

INSYNC SENTRY®7299 Reference Manual

1Quick reference

Stored data and diagnostics

1.7 Stored data and diagnostics

Table 8. Stored data and diagnostics

Episode data

Tachy episodes 150 VF/VT/FVT episodes: intervals, text, EGM

EGM capacity for tachy episodes 14 min of dual-channel EGM or 23.5 min of

SVT/NST episodes 50 SVT/NST episodes: intervals, text, EGM (the device

EGM capacity for SVT/NST episodes

EGM sources 14 options: atrial/ RV / LV / far-ﬁeld

EGM options Store before onset; Store during charging

Flashback memory 2000 intervals (containing both A-A and V-V): before

Mode Switch episodes 53 Mode Switch episodes (fastest, longest, ﬁrst and 50

Ventricular sensing episodes 9 ventricular sensing episodes (longest, ﬁrst, and 7

Counter data

Detection counters Lifetime total, since cleared, and since last session

Episode counters Episodes:

Therapy efﬁcacy counters Counts for each VF, FVT, VT Therapy:

single-channel EGM

does not usually store detailed episode records for NST episodes)

2 min of dual-channel EGM or 3.6 min of single-channel EGM

latest VF, before latest VT, and before interrogation

latest): episode text

latest): intervals, markers, and counter data text

VF, FVT, and VT

•

Atrial Fibrillation/Atrial Flutter episodes

•

Sinus Tach episodes

•

Other 1:1 SVT episodes

•

NST episodes

•

Mode Switch episodes

•

Percentage pacing:

AS-VS, AS-VP, AP-VS, AP-VP percentages

•

Additional counters:

Single PVCs and PVC runs

•

Rate stabilization pulses and runs

•

Delivered

•

Successful

•

Unsuccessful

•

Intervention (manually aborted)

•

Total number of aborted shocks

INSYNC SENTRY®7299 Reference Manual

Chapter 1

New and enhanced features

Table 8. Stored data and diagnostics (continued)

Other stored data

Patient Alert — System events Up to 10 log entries: text and date for the ﬁrst time an

Battery and lead measurements Battery voltage, last capacitor formation, last charge,

Lead performance trends 14 days of daily measurements plus 80 weeks of weekly

Rate Histograms

Cardiac Compass trends 14 months of daily measurements:

alert is triggered between interrogations

lead impedance, EGM amplitude measurements, last high-voltage therapy, and sensing integrity counter

minimum and maximum measurements:

lead impedance: atrial pacing, RV pacing, LV

•

pacing, deﬁbrillation pathway, and SVC lead (if used)

atrial EGM amplitude (P-waves)

•

Atrial rate

•

Ventricular rate

•

Ventricular rate during AT/AF

•

VT and VF episodes per day

•

one or more high-voltage therapy delivered

•

ventricular rate during VT or VF

•

episodes of non-sustained tachycardia per day

•

total daily time in AT/AF

•

ventricular rate during AT/AF

•

percent pacing per day

•

average day and night ventricular heart rate

•

patient activity

•

heart rate variability

•

thoracic impedance

•

accumulated differences between the daily and

•

reference thoracic impedance (OptiVol ﬂuid index)

1.8 New and enhanced features

The following features are new or changed from the 7289 InSync II Marquis ICD.

1.8.1 Patient management

OptiVol Fluid Monitoring – The OptiVol Fluid Monitoring

feature is designed to assist the physician in assessing the

INSYNC SENTRY®7299 Reference Manual

patient’s thoracic ﬂuid status. When the device determines that the patient’s thoracic ﬂuid status has exceeded a programmed threshold, an observation is displayed on the Quick Look screen and Heart Failure Management Report at the next interrogation.

The OptiVol Fluid Monitoring feature is an additional source of information for patient management and does not replace assessments that are part of standard clinical practice.

OptiVol Fluid Trends – There are 2 OptiVol Fluid Trends:

The Thoracic impedance trend plots thoracic impedance for

•

up to 14 months. The Daily thoracic impedance is measured

between the RVcoil and Can.

The OptiVol ﬂuid index trend plots the accumulated

•

differences between the daily and reference thoracic

impedance. Thoracic ﬂuid accumulation may exist when the

OptiVol ﬂuid index is greater than the OptiVol threshold.

The OptiVol Fluid Trends are included in the Cardiac Compass and Heart Failure Management reports. For more information on each trend, see Section 12.5.2.

1.8.2 Tachyarrhythmia therapy

1Quick reference

New and enhanced features

Output – The InSync Sentry CRT-D has a maximum delivered energy of 35 J.

1.8.3 Cardiac resynchronization therapy

Sequential biventricular pacing – The ventricular sequence

and V-V pace delay are programmable to support improved hemodynamics.

Pacing outputs for RV and LV are independently programmable.

INSYNC SENTRY®7299 Reference Manual

2The InSync Sentry system

2.1 System overview 29

2.2 Indications and usage 33

2.3 Contraindications 33

2.4 Patient screening 33

2.1 System overview

The Model 7299 InSync Sentry dual chamber implantable cardioverter deﬁbrillator with cardiac resynchronization therapy (CRT-D) including sequential biventricular pacing and OptiVol Fluid Monitoring is an implantable medical device system that includes 3 major components:

CRT-D device

•

leads

•

programmer, software, and accessories

•

Each of these components is described in detail below.

Device – The device senses the electrical activity of the patient’s heart using the sensing electrodes of the implanted atrial and right ventricular leads. It then analyzes the heart rhythm based on selectable sensing and detection parameters. The device provides the following functions:

simultaneous or sequential biventricular pacing for cardiac

•

resynchronization

automatic detection and treatment of ventricular

•

tachyarrhythmias (ventricular ﬁbrillation, ventricular

tachycardia, and fast ventricular tachycardia) with

deﬁbrillation, cardioversion, and antitachycardia pacing

therapies

single or dual chamber pacing for patients requiring rate

•

support

diagnostics and monitors that evaluate the system and assist

•

in patient care

2The InSync Sentry system

System overview

Leads – The device can be used with transvenous or epicardial deﬁbrillation leads. The lead system should consist of bipolar or paired unipolar pacing/sensing leads in the right atrium and right ventricle of the heart, a pacing lead for the left ventricle, and 1 or 2 high-voltage cardioversion/deﬁbrillation electrodes. In addition to the lead system, the Active Can feature enables the device to act as one of the high-voltage electrodes. The device delivers pacing and cardiac resynchronization therapy via the atrial (A), right ventricular (RV), and left ventricular (LV) leads. The device senses using the atrial and RV leads. Cardioversion/deﬁbrillation therapy is delivered with 2 lead-based high-voltage electrodes, or with the Active Can deﬁbrillation electrode and 1 or 2 lead-based high-voltage electrodes.

INSYNC SENTRY®7299 Reference Manual

Chapter 2

System overview

The OptiVol Fluid Monitoring feature may be adversely affected by the use of an epicardial deﬁbrillation lead instead of an RVcoil.

Prior to implanting the left ventricular pacing lead, thoroughly read the associated left ventricular lead technical manual.

Programmer and software – The Medtronic CareLink Programmer, Model 2090,1and Model 9998 software application allow you to perform the following functions:

conﬁgure the cardiac resynchronization, arrhythmia detection

•

and therapy, and bradycardia features for your patient

perform electrophysiological studies and system tests

•

monitor, display, or print patient cardiac activity information

•

Network connectivity and data exchange – The system supports network connectivity and the exchange of data between the Medtronic Carelink 2090 programmer and the Medtronic Paceart data management system using the SessionSync feature.

Concurrent Analyzer – The system supports the use of the Medtronic 2290 Analyzer, which allows you to have a device session and an analyzer session running at the same time, quickly switch from one to the other without having to end or restart sessions, and export data from the analyzer to the device software application.

Remote View – The system supports Remote View, which allows you to use a personal computer in your ofﬁce or elsewhere to view the screen displays from a Medtronic Carelink programmer in a clinic, hospital, or other location.

With the Model 2067 or Model 2067L programming head.

INSYNC SENTRY®7299 Reference Manual

For information about:

indications, contraindications, warnings and precautions,

•

see the implant manual that accompanies the device.

basic programmer and software desktop functions

•

that are not included in Chapter 10, “Using the programmer”, page 223, see the manual accompanying the programmer.

installing the Model 2067 or Model 2067L programming

•

head, see the manuals accompanying the programming heads.

implanting leads and using implant tools, refer to the

•

manuals accompanying the leads and implant tools.

2.1.1 Cardiac resynchronization

To improve cardiac output in patients with ventricular dyssynchrony, the device provides biventricular pacing. The device paces either the right ventricle or both ventricles as programmed, unless pacing is inhibited by a sensed event in the RV.

Ventricular pacing sequence, V-V pace delay and LV pacing

•

vector are programmable.

Optional CRT features promote sustained resynchronization

•

pacing that could be interrupted during episodes of

accelerated AV conduction, atrial rate excursions, PVCs, or

atrial arrhythmia.

Pacing amplitudes and pulse widths are selected

•

independently for each ventricle.

2The InSync Sentry system

System overview

2.1.2 Detecting and treating tachyarrhythmias

The device monitors the cardiac rhythm for short ventricular intervals that may indicate the presence of VF, VT, or FVT.

Upon detection of VF, the device delivers a biphasic

•

deﬁbrillation shock of up to 35 J. If the VF episode persists,

up to 5 more individually programmed deﬁbrillation shocks

can be delivered.

Upon detection of VT, the device delivers either a Ramp,

•

Ramp+, or Burst antitachycardia pacing therapy or a

biphasic cardioversion shock of up to 35 J synchronized to

a ventricular depolarization. If the VT episode persists, up

to 5 more individually programmed VT therapies can be

INSYNC SENTRY®7299 Reference Manual

Chapter 2

System overview

•

You can program the device to distinguish between true ventricular arrhythmias and rapidly conducted supraventricular tachyarrhythmias (SVT) and withhold therapy for SVT.

SVT discrimination includes the capability to detect a double tachycardia (an unrelated ventricular arrhythmia occurring simultaneously with an SVT) so that therapy is not withheld for a ventricular arrhythmia in the presence of an SVT.

2.1.3 Treating bradycardia

The device provides rate responsive pacing to optimize hemodynamics. An internal accelerometer senses the patient’s physical activity, allowing the device to increase and decrease the pacing rate in response to changes in the level of activity.

delivered. You can also program the device to monitor the VT episode without delivering therapy.

Upon detection of FVT, the device delivers either a Ramp, Ramp+, or Burst antitachycardia pacing therapy or a biphasic cardioversion shock of up to 35 J synchronized to a ventricular depolarization. If the FVT episode persists, up to 5 more individually programmed FVT therapies can be delivered.

2.1.4 Monitoring for real-time and stored data

The device and programmer provide real-time information on detection and therapy parameters and status during a patient session. The device also provides accumulated data on device operation, including ventricular sensing episodes, stored electrograms, detected and treated tachyarrhythmia episodes, bradycardia interventions, and the efﬁcacy of therapy. The Cardiac Compass report provides up to 14 months of clinically signiﬁcant data, including physical activity, heart rate, percent pacing, arrhythmia episodes, and therapies delivered.

All of this information can be printed and retained in the patient’s ﬁle or saved in electronic format on a ﬂoppy diskette.

2.1.5 Conducting electrophysiologic tests

You can use the system to conduct non-invasive electrophysiologic studies, including manual delivery of any of the device therapies, to manage an induced or spontaneous tachyarrhythmia.

INSYNC SENTRY®7299 Reference Manual

2.1.6 Alerting the patient to system events

You can use the programmable Patient Alert monitoring feature to notify the patient with audible tones if certain conditions related to the leads, battery, charge time, and therapies occur. The patient can then respond based on your prescribed instructions.

2.2 Indications and usage

The InSync Sentry is indicated for ventricular antitachycardia pacing and ventricular deﬁbrillation for automated treatment of life threatening ventricular arrhythmias. The system is also indicated for the reduction of the symptoms of moderate to severe heart failure (NYHA Functional Class III or IV) in those patients who remain symptomatic despite stable, optimal medical therapy and have a left ventricular ejection fraction ≤ 35% and a prolonged QRS duration.

2.3 Contraindications

2The InSync Sentry system

Indications and usage

Do not use the InSync Sentry system in the following types of patients:

patients whose ventricular tachyarrhythmias may have

•

transient or reversible causes, such as:

– acute myocardial infarction – drug intoxication – drowning – electric shock – electrolyte imbalance – hypoxia – sepsis

patients with incessant VT or VF

•

patients who have a unipolar pacemaker

•

2.4 Patient screening

Before implant, patients should undergo a complete cardiac evaluation, including electrophysiologic testing. Also, electrophysiologic evaluation and testing of the safety and efﬁcacy

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Chapter 2

Patient screening

of the proposed tachyarrhythmia therapies are recommended during and after device implant.

Other optional screening procedures could include exercise stress testing to determine the patient’s maximum sinus rate, and cardiac catheterization to determine if there is a need for concomitant surgery, medical therapy, or both.

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3Emergency therapy

3.1 Delivering emergency therapies 37

3.2 Delivering an emergency deﬁbrillation therapy 38

3.3 Delivering an emergency cardioversion therapy 39

3.4 Delivering emergency ﬁxed burst pacing 39

3.5 Enabling emergency VVI pacing 40

3.1 Delivering emergency therapies

The device provides the following emergency therapies:

deﬁbrillation

•

cardioversion

•

ﬁxed burst pacing

•

emergency VVI pacing

•

The default emergency therapy is 35 J deﬁbrillation. When you select [Emergency] and [DELIVER], the device charges and delivers a biphasic 35 J shock along the AX>B pathway.

The programmer resets the emergency deﬁbrillation energy to 35 J each time you select [Emergency]. Emergency cardioversion and ﬁxed burst values remain as selected for the duration of the session.

To return to other programming functions from an Emergency screen, select [Exit Emergency].

3.1.1 Effect on system operation

3Emergency therapy

Delivering emergency therapies

The device suspends the automatic detection features when emergency deﬁbrillation, cardioversion, or ﬁxed burst pacing therapies are delivered. Detection is not suspended during emergency VVI pacing. Removing the programming head or pressing [Resume] turns detection on again.

3.1.2 Aborting an emergency therapy

As a safety precaution, the programmer also displays an [ABORT] button, which immediately terminates any emergency therapy in progress.

3.1.3 Mechanical Emergency VVI button on the Medtronic CareLink Model 2090 programmer

If you press the red Emergency VVI button on the programmer display panel, the device initiates Emergency VVI pacing and the programmer displays the Emergency screen.

If Active Can is turned off, the deﬁbrillation is delivered between the HVX and HVB electrodes.

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Chapter 3

Delivering an emergency deﬁbrillation therapy

3.1.4 Temporary parameter values

Emergency tachyarrhythmia therapies use temporary values that do not change the programmed parameters of the device. These values are not in effect until you select [DELIVER]. After the tachyarrhythmia therapy is complete, the device reverts to its programmed values.

3.2 Delivering an emergency deﬁbrillation therapy

The default emergency therapy is a full-energy deﬁbrillation. When you select [Emergency] and [DELIVER], the device charges and delivers a biphasic full-energy shock. The programmer sets the emergency deﬁbrillation energy to its maximum value each time you select [Emergency] or select the [Deﬁbrillation] option from an Emergency screen.

3.2.1 How to deliver emergency deﬁbrillation

1. Position the programming head over the device.

2. Select [Emergency].

3. Accept the deﬁbrillation energy shown on the screen, or select a new Energy value.

4. Select [DELIVER]. If delivery is not conﬁrmed,

verify that the programming head is properly positioned, and select [Retry] or [Cancel].

INSYNC SENTRY®7299 Reference Manual

Delivery of Emergency VVI Pacing changes the programmed bradycardia pacing values to the emergency values (see Section 3.5).

3Emergency therapy

Delivering an emergency cardioversion therapy

3.3 Delivering an emergency cardioversion therapy

When you initiate an emergency cardioversion therapy, the device charges its capacitors to the selected energy and attempts to deliver therapy synchronized with a sensed tachyarrhythmia event. If the cardioversion therapy cannot be synchronized, it is aborted. See Section 7.3.5.6.

3.3.1 How to deliver emergency cardioversion

1. Position the programming head over the device.

2. Select [Emergency].

3. Select [Cardioversion].

4. Accept the deﬁbrillation energy shown on the screen, or select a new Energy value.

5. Select [DELIVER]. If delivery is not conﬁrmed,

verify that the programming head is properly positioned and select [Retry] or [Cancel].

3.4 Delivering emergency ﬁxed burst pacing

Emergency ﬁxed burst pacing delivers maximum output pacing pulses to the ventricle at a selectable interval. The therapy continues for as long as you keep the programmer stylus on the [BURST Press and Hold] button.

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Chapter 3

Enabling emergency VVI pacing

3.4.1 How to deliver emergency ﬁxed burst pacing

3.5 Enabling emergency VVI pacing

1. Position the programming head over the device.

2. Select [Emergency].

3. Select [Fixed Burst].

4. Accept the pacing interval shown on the screen, or select a new interval value.

5. Select [BURST Press and Hold]. If delivery is not conﬁrmed,

the programmer displays an error window. Verify that the programming head is properly positioned. Select [OK] from the window and reselect [BURST Press and Hold].

Emergency VVI pacing programs the device to deliver high-output ventricular pacing. You can initiate emergency VVI pacing from the Emergency screen or by pressing the red mechanical button on the Medtronic CareLink Model 2090 programmer display panel. To disable emergency VVI pacing, reprogram the bradycardia pacing parameters from the Parameters screen.

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3.5.1 How to deliver emergency VVI pacing

3Emergency therapy

Enabling emergency VVI pacing

1. Position the programming head over the device.

2. Select [Emergency].

3. Select [VVI Pacing].

4. Select [PROGRAM]. A successful programming sets the device to the following maximum output bradycardia pacing values:

Pacing Mode: VVI

•

Lower Rate: 70 ppm

•

RV. Amplitude: 6 V

•

RV. Pulse Width: 1.6 ms

•

V. Pace Blanking: 240 ms

•

V. Pacing: RV

•

V. Sense Response: Off

•

Ventricular Rate

•

Stabilization: Off Cond AF Response: Off

•

If programming is not conﬁrmed, verify that the programming head is properly positioned and select [Retry] or [Cancel].

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Device implant and patient follow-up procedures

Part II

4Implanting the device

4.1 Implant overview 47

4.2 Preparing for an implant 47

4.3 Replacing a device 49

4.4 Surgical approach 50

4.5 Sensing and pacing measurements 54

4.6 Connecting the leads to the device 54

4.7 Testing deﬁbrillation operation and effectiveness 58

4.8 Positioning and securing the device 61

4.9 Completing the implant procedure 61

4.1 Implant overview

The tasks for implanting a device include:

1. Preparing for an implant

2. Replacing a device

3. Surgical approach

4. Sensing and pacing measurements

5. Connecting the leads to the device

6. Testing deﬁbrillation operation and effectiveness

7. Positioning and securing the device

8. Completing the implant procedure

These tasks are described in the sections that follow.

4.2 Preparing for an implant

Warning: Keep external deﬁbrillation equipment nearby

for immediate use whenever arrhythmias are possible or intentionally induced during device testing, implant procedures, or post-implant testing.

4Implanting the device

Implant overview

Warning: Do not permit the patient to contact grounded equipment that could produce hazardous leakage current during implant. Resulting arrhythmia induction could result in the patient’s death.

The device is intended for implant in the pectoral region with Medtronic transvenous deﬁbrillation leads. Implanting the device outside of the pectoral region, or the use of an epicardial deﬁbrillation lead instead of an RVcoil (HVB) may adversely affect the results of the OptiVol ﬂuid measurements. No claims of safety and efﬁcacy can be made with regard to other acutely or chronically implanted lead systems that are not manufactured by Medtronic.

4.2.1 Equipment for an implant

Medtronic CareLink Programmer Model 2090 and Model

•

2067 or 2067L programming head

Model 9998 software application

•

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Chapter 4

Preparing for an implant

Model 8090 Analyzer lead analysis device or equivalent

•

pacing system analyzer

external deﬁbrillator

•

Model 5358 Deﬁbrillator Implant Support Device and

•

software application (optional)

4.2.2 Sterile supplies

InSync Sentry and lead system components

•

Programming head sleeve or programming head

•

Analyzer cables

•

Lead introducers or delivery systems appropriate for the

•

lead system

Extra stylets of appropriate length and shape

•

4.2.3 How to set up the implant support instrument

When using an implant support instrument such as the Model 5358 Deﬁbrillator Implant Support device, perform these steps:

1. Calibrate any monitoring or recording equipment while recording the EGM and marker outputs of the support instrument.

2. Verify the high-energy output of the support instrument by delivering a high-energy deﬁbrillation shock into the test load.

4.2.4 How to set up the programmer and start the application

1. Set up the programmer as described in the instructions provided with the programmer.

2. Install the InSync Sentry Model 9998 software on the programmer if it is not already installed.

3. Place the programming head over the device, and start the application. Select the device model or select [Auto identify].

Note: The programmer automatically interrogates the device when the application starts.

4.2.5 How to preprogram the device

Before opening the sterile package, prepare the device for implant as follows:

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4Implanting the device

Replacing a device

1. Check the “Use by” date printed on the package. Do not implant the device after the “Use by” date because the battery’s longevity can be reduced.

2. Interrogate the device and print a full summary report. Note: If the programmer reports that an electrical reset occurred,

do not implant the device. Contact a Medtronic representative.

3. Conﬁrm that the battery voltage is at least 3.0 V at room temperature.

If the device temperature is lower than room temperature or the device has delivered a recent high-voltage charge, the battery voltage will be temporarily lower.

4. Set up data collection parameters and the device internal clock (see Section 12.9.3, “How to set up data collection”, page 318).

5. Perform a manual capacitor formation (see “Manual capacitor formation”, page 340).

6. Program the therapy and pacing parameters to values appropriate for the patient (see Section 8.1.4, “How to program CRT and bradycardia pacing parameters”, page 158). Ensure that all tachyarrhythmia detection is programmed to Off (see Chapter 6, “Detecting tachyarrhythmias”, page 73).

Note: Do not enable VF Detection until the device has been successfully implanted.

4.3 Replacing a device

If you are replacing a previously implanted device, turn off device detection and therapies before explanting.

When implanting the device with a chronic lead system, perform the following evaluations to ensure appropriate detection and therapy:

Check the integrity of the chronic high-voltage leads with a

•

test shock, chest x-ray, and inspection.

Perform chronic pacing and sensing measurements.

•

Measure high-voltage lead impedances.

•

Test deﬁbrillation efﬁcacy.

•

Conﬁrm adequate sensing during VF.

•

Use the Quick Look screen to verify the voltage; see Section 11.2.2, “Quick Look observations”, page 264.

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Chapter 4

Surgical approach

Ensure proper ﬁt of the lead connectors in the device

•

connector block.

Notes:

To meet the implant requirements, it may be necessary to

•

reposition or replace the chronic leads or to add a third high-voltage electrode.

Any unused leads that remain implanted must be capped.

•

4.3.1 How to explant and replace a device

1. Program all tachyarrhythmia detection to Off.

2. Dissect the leads and the device free from the surrounding tissues in the surgical pocket. Be careful not to nick or breach the lead insulation during the process of exposing the system.

3. Loosen each setscrew, and gently retract the lead from the connector block.

4. Remove the device from the surgical pocket.

5. If the connector pin of any implanted lead shows signs of pitting or corrosion, replace the implanted lead with a new lead. The damaged lead should be discarded and replaced to assure the integrity of the device system.

6. Measure sensing, pacing, and deﬁbrillation efﬁcacy using the replacement device or an implant support instrument.

4.4 Surgical approach

The InSync Sentry system typically requires that a left ventricular lead be implanted in the coronary sinus and positioned in a cardiac vein. For this reason, physicians should expect that implanting an InSync Sentry system will require more time than implanting a traditional ICD or pacemaker system.

4.4.1 Implanting the device

In most cases the device is implanted in the pectoral region, either submuscularly or subcutaneously, using transvenous leads for pacing, sensing, and high-voltage therapies.

INSYNC SENTRY®7299 Reference Manual

Follow these single-incision guidelines when implanting the device in the pectoral region. The pocket should be about 1.5 times the size of the device.

Submuscular approach: A single incision that extends over

•

the delta-pectoral groove can provide access to the cephalic and subclavian veins and access to form the implant pocket. Place the device sufﬁciently medial to the humeral head to avoid interference with shoulder motion.

Subcutaneous approach: The subcutaneous approach can

•

be similar to the approach used in a pacemaker implant. Use a single transverse incision long enough to permit isolation of the cephalic and subclavian veins. Place the device quite far medially to keep the leads away from the axilla, and keep the upper edge of the device inferior to the incision.

4.4.2 Lead conﬁgurations

The device is typically implanted with the following leads:

one transvenous lead for the left ventricle (LV) for pacing

•

one bipolar transvenous lead in the right ventricle (RV) for

•

sensing, pacing, and cardioversion/deﬁbrillation therapies

one bipolar transvenous lead in the atrium (A) for sensing

•

and pacing

4Implanting the device

Surgical approach

The InSync Sentry system is an Active Can system in which the device case serves as a high-voltage electrode. The device case, the RV coil, and the SVC coil form a 3 electrode system for simultaneous mode deﬁbrillation and cardioversion. High-voltage therapies are delivered between the RV coil and the combined device case and SVC coil.

The device may be implanted with other transvenous leads. Refer to Section 4.4.4, “Using other transvenous leads”, page 53, for more information.

Notes:

Medtronic 3.2 mm low-proﬁle leads are not directly

•

compatible with the device IS-1 connector block.

For questions about lead and device compatibility, please

•

contact your Medtronic representative.

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Chapter 4

Surgical approach

4.4.3 Implanting the lead

Note: Do not implant the LV, atrial, and RV leads in the same

venous access site. Medtronic recommends implanting the LV lead in the subclavian vein, and the atrial and RV leads in the cephalic vein.

If inserting the lead using a subclavian approach, position the lead laterally to avoid pinching the lead body between the clavicle and the ﬁrst rib. Pinching the lead may eventually cause conductor fracture, damage to the insulation, or other damage to the lead. This may result in complications such as loss of detection, loss of pacing therapies, or loss of cardioversion/deﬁbrillation therapy.

Certain anatomical abnormalities, such as thoracic outlet syndrome, may also cause pinching and subsequent fracture of the lead. If signiﬁcant resistance is encountered during a subclavian stick implant procedure, do not force passage of the lead by adjusting the patient’s posture (by raising the arm or putting a towel behind the person’s back, for example). Use an alternate venous entry site instead.

4.4.3.1 Implanting the ventricular leads

Warning: Backup pacing should be readily available during

implant. Use of the delivery system or leads may cause heart block.

Note: Due to the variability of cardiac venous systems, the venous anatomy should be assessed before implanting the LV lead to determine an optimal LV lead position. Before placing a lead in the coronary sinus, obtain a venogram.

When implanting a LV or RV lead, follow the directions for use in the respective lead technical manuals.

Final lead positioning should attempt to optimize both cardiac resynchronization and deﬁbrillation threshold.

When pacing at 10 V using an external pacing device, test for extracardiac stimulation from the LV lead. If extracardiac stimulation is present, consider repositioning the lead.

4.4.3.2 Implanting the right atrial lead

Implant the atrial lead in the cephalic vein, if possible. Follow the directions for use in the lead technical manual.

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4.4.3.3 Lead positioning

For the initial lead conﬁguration the following positions are recommended:

LV tip electrode – Position the LV tip electrode as far laterally into the coronary venous system as possible (so that deﬂection of the LV EGM signal occurs as late as possible in the QRS complex).

RV tip electrode – Position the RV tip electrode as far apically as possible (so that deﬂection of the RV EGM signal on the RV electrode starts early in the QRS complex). Deﬁbrillation threshold, atrial far-ﬁeld sensing and RV-LV timing must be considered when choosing the optimal location.

Atrial tip electrode – The atrial tip electrode should be positioned close to the SA node or on the lateral wall to minimize the possibility of far-ﬁeld R-wave oversensing. Lead placement in these positions potentially provides optimal atrial sensing while reducing far-ﬁeld R-wave sensing.

4.4.4 Using other transvenous leads

4Implanting the device

Surgical approach

Follow the general guidelines below for initial positioning of other transvenous leads (the ﬁnal positions are determined by deﬁbrillation efﬁcacy tests):

For an SVC lead, place the lead tip high in the innominate

•

vein, approximately 5 cm proximal to the atrium (A) and SVC junction.

For an SQ patch lead, place the patch along the left

•

midaxillary line, centered over the fourth-to-ﬁfth intercostal space.

4.4.5 Using epicardial lead systems

Note: The OptiVol Fluid Monitoring feature may be adversely

affected by the use of an epicardial deﬁbrillation lead instead of an RVcoil.

Observe the following guidelines when epicardial lead systems are implanted:

The distance between the RVring electrode and the RVtip

•

electrode should not exceed 1 cm.

The RVtip electrode should not lie in a direct path between

•

epicardial patches.

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Chapter 4

Sensing and pacing measurements

The RVtip/RVring and Atip/Aring intrinsic, post-pace, and

•

post shock electrograms should be thoroughly evaluated for oversensing, undersensing, cross-talk, and noise.

The pacing thresholds and electrogram characteristics

•

should meet the values indicated in Table 9.

4.5 Sensing and pacing measurements

Sensing and pacing measurements include EGM amplitudes, slew rates, capture thresholds, and pacing lead impedances. Medtronic recommends using the Model 8090 Analyzer for sensing and pacing measurements. Refer to the Analyzer technical manual for detailed procedures on performing these measurements.

Do not use the intracardiac EGM telemetered from the device to assess sensing.

Table 9 lists the acceptable implant values for acute and chronically implanted lead systems.

Table 9. Acceptable implant values

Measurement required Acute Chronic

A RV LV A RV LV

EGM amplitude (during NSR) ≥ 2 mV ≥ 5 mV ≥ 3 mV ≥ 1 mV ≥ 3 mV ≥ 1 mV

Slew rate

Capture threshold (0.5 ms pulse width)

Typical pacing lead impedance

Verify adequate pacing threshold margins at implant and at each follow-up visit.

The measured pacing lead impedance is a reﬂection of measuring equipment and lead technology.

Refer to the technical manual for the speciﬁc lead model for detailed information about acceptable

impedance values.

≥

0.5 V/s≥0.75 V/s

≤ 1.5 V ≤ 1.0 V ≤ 3.0 V ≤ 3.0 V ≤ 3.0 V ≤ 4.0 V

250 - 1000 Ùc(all)

—

≥

0.3 V/s≥0.5 V/s

—

4.6 Connecting the leads to the device

For more detailed information about lead/connector compatibility, see the Medtronic representative.

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InSync Sentry 7299 Implant Manual, or contact your

4Implanting the device

Connecting the leads to the device

Table 10. Lead connections

Device port Connector type Software name

SVC (HVX) DF-1 SVC

RV (HVB) DF-1 RVcoil

Can (HVA)

RV IS-1 bipolar RVtip and RVring

LV IS-1 bipolar LVtip and LVring

A IS-1 bipolar Atip and Aring

Figure 3. Device ports for lead connections

—

Can

1 SVC (HVX) 2 RV (HVB) 3 Can (HVA) 4 LV 5 RV 6 A

Caution: Loose lead connections may result in inappropriate sensing and failure to deliver necessary arrhythmia therapy.

Cautions:

To ensure appropriate sensing and detection, insert the

•

right ventricular lead IS-1 connector into the RV port and insert the right ventricular lead DF-1 connector into the RV (HVB) port.

If no SVC electrode is implanted, the pin plug provided

•

with the device must be secured in the SVC (HVX) port.

Use only the torque wrench supplied with the device.

•

It is designed to prevent damage to the device from overtightening a setscrew.

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Chapter 4

Connecting the leads to the device

Notes:

•

Do not reuse the torque wrench after this implant.

•

Lead and Active Can electrodes in electrical contact

•

with each other during a high-voltage therapy could cause current to bypass the heart, possibly damaging the device and leads. While the device is connected to the leads, make sure that no therapeutic electrodes, stylets, or guide wires are touching or connected by an accessory low impedance conductive pathway. Move any objects that contain conductive materials (e.g., an implanted guide wire) well away from all electrodes before a high-voltage shock is delivered.

For easier lead insertion, insert the LV IS-1 lead before the other leads.

If a chronic lead system uses a different size or number of leads, insert the lead connectors into appropriate adaptors. See the appropriate lead technical manuals for more details.

Upon initial lead connection to the connector block, LVtip, RVtip, and RVcoil all need to be connected within the connector block to provide biventricular pacing.

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4Implanting the device

Connecting the leads to the device

4.6.1 How to connect the lead to the device

1. Insert the torque wrench into the appropriate setscrew.

a. If the port is obstructed by

the setscrew, retract the setscrew to clear it. Take care not to disengage the setscrew from the connector block.

b. Leave the torque wrench in

the setscrew until the lead is secure. This allows a pathway for venting trapped air when the lead is inserted.

2. Push the lead or plug into the connector port until the lead pin is clearly visible in the pin viewing area. No sealant is required, but sterile water may be used as a lubricant.

3. Tighten the setscrew by turning clockwise until the torque wrench clicks.

4. Tug gently on the lead to conﬁrm a secure ﬁt. Do not tug on the lead until all setscrews have been tightened.

5. Repeat these steps for each connector port.

4.6.2 Post pace oversensing testing

Changes in the programmed ventricular pacing conﬁguration (RV, RV→LV, or LV→RV) may evoke slightly different EGMs. To ensure proper sensing regardless of the pacing conﬁguration, or in the event of lead dislodgment or failure, the sensing behavior during pacing for all conﬁgurations should be evaluated as follows:

1. Program RV Pacing.

2. Print a 10 to 30 s test strip.

3. Check for post pace oversensing.

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Chapter 4

Testing deﬁbrillation operation and effectiveness

Repeat Step 1 through Step 3 with ventricular pacing programmed to RV→LV and LV→RV.

If oversensing occurs during one of the pacing conﬁgurations, repositioning of the RV lead may help alleviate the oversensing.

4.7 Testing deﬁbrillation operation and effectiveness

Demonstrate reliable deﬁbrillation effectiveness with the implanted lead system by using your preferred method to establish that a 10 J (minimum) safety margin exists.

Note: If the 10 J (minimum) safety margin cannot be ensured, see Section 15.5, “Solving tachyarrhythmia therapy problems”, page 365.

4.7.1 High-voltage implant values

Measured values must meet the following requirements at implant.

Table 11. High-voltage therapy values at implant

Measurement Acute or Chronic Leads

V. Deﬁb impedance 20 – 200 Ù

SVC (HVX) impedance (if applicable) 20 – 200 Ù

Deﬁbrillation threshold ≤ 25 J

Warning: Ensure that an external deﬁbrillator is charged for a rescue shock.

4.7.2 How to prepare for deﬁbrillation threshold testing

1. Place the programming head over the device, start a patient session, and interrogate the device, if you have not already done so.

2. Observe the Marker Channel telemetry annotations and the programmer ECG display to verify that the device is sensing properly.

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4Implanting the device

Testing deﬁbrillation operation and effectiveness

3. Conduct a manual Lead Impedance Test lead connections. Perform this test with the device in the surgical pocket, and keep the pocket very moist. If the impedance is out of range, perform one or more of the following tasks:

Recheck lead connections and electrode placement.

•

Repeat the measurement.

•

Inspect the bipolar EGM for abnormalities.

•

Measure the deﬁbrillation impedance with a manual test shock.

•

4. Program the device or support instrument to properly detect VF with an adequate safety margin (1.2 mV sensitivity).

to verify the deﬁbrillation

See Section 13.4, “Measuring lead impedance”, page 335 .

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7 8

Chapter 4

Testing deﬁbrillation operation and effectiveness

4.7.3 How to perform deﬁbrillation threshold testing

1. Select Tests > EP Study.

2. Select either 50 Hz BURST or T-shock induction.

3. Select [Resume at BURST] or [Resume at DELIVER].

4. Select [Adjust Permanent…].

5. Program VF Enable On.

6. Program the automatic therapy energy settings. Therapies 2 through 6 should be set to the maximum energy.

7. Select [Program].

8. Select [Close].

9. If performing a T-Shock induction, select the [Enable] checkbox.

10. Select [DELIVER], or [50 Hz BURST Press and Hold].

If necessary, you can abort an induction or therapy in progress by pressing [ABORT].

11. Observe the live rhythm monitor for proper post-shock sensing.

12. Use the [Adjust Permanent…] button to program the next appropriate energy level.

13. Wait until the on-screen timer reaches 5 min, then repeat Step 9 through Step 12 as needed.

14. Select Params > Detection and program VF, FVT, and VT detection Off before closing.

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Positioning and securing the device

4.8 Positioning and securing the device

Cautions:

If no SVC electrode is implanted, the pin plug provided

•

with the device must be secured in the SVC (HVX) port.

Program tachyarrhythmia detection to Off before closing.

•

4.8.1 How to position and secure the device

1. Ensure that each lead pin or plug is fully inserted into the connector block and that all setscrews are tight.

2. Coil any excess lead length beneath the device. Avoid kinks in the lead conductors.

3. Implant the device within 5 cm of the skin and with the Medtronic label facing the skin for improved Patient Alert volume. This position optimizes the ambulatory monitoring operations.

4. Use nonabsorbable sutures to secure the device within the pocket to minimize post-implant rotation and migration of the device. Use a surgical needle to penetrate the suture holes.

4Implanting the device

4.9 Completing the implant procedure

After implanting the device, obtain an x-ray of the patient to verify device and lead placement. To complete programming the device, select parameters that are appropriate for the patient.

4.9.1 How to complete programming the device

1. After closing the pocket, program detection to On. Program ventricular tachyarrhythmia therapies to On as desired.

2. Do not enable the Other 1:1 SVTs PR Logic detection criterion until the atrial lead has matured (approximately 1 month post implant).

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Chapter 4

Completing the implant procedure

3. If external equipment was used to conduct the deﬁbrillation efﬁcacy

4. Monitor the patient after the implant, and take x-rays as soon as

5. Program patient information. See Section 12.10, “Viewing and

6. Conﬁgure the Patient Alert feature. See Section 11.3, “Using the

7. Set up data collection parameters. See Section 12.9, “Setting up

8. Interrogate the device after any spontaneous episodes to evaluate

9. If the patient has not experienced spontaneous episodes, you

10. Recheck pacing and sensing values, and adjust if necessary. See

tests, perform a ﬁnal VF induction, and allow the implanted system to detect and treat the arrhythmia.

possible to document and assess the location of the leads.

entering patient information”, page 322.

Patient Alert feature”, page 265.

data collection”, page 316.

the detection and therapy parameter settings.

may induce the clinical tachyarrhythmias using the non-invasive EP Study features to further assess the performance of the system. See Chapter 14, “Conducting Electrophysiologic Studies”, page 341.

Section 13.3, “Measuring pacing thresholds”, page 332.

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5Conducting a patient follow-up session

5.1 Patient follow-up guidelines 65

5.2 Verifying the status of the implanted system 65

5.3 Verifying effective cardiac resynchronization therapy 66

5.4 Verifying effective basic pacing 67

5.5 Verifying accurate detection and appropriate therapy for ventricular tachyarrhythmias 68

5Conducting a patient follow-up session

5.1 Patient follow-up guidelines

Schedule regular patient follow-up sessions to monitor the condition of the device and leads and to verify that the device is conﬁgured appropriately for your patient.

During the ﬁrst few months after receiving a new device, the patient may require close monitoring. Schedule an ofﬁce visit at least every 3 months.

The Quick Look screen, which is displayed after you interrogate the device, provides a good beginning for the follow-up review. Using this screen you can perform the following tasks:

Verify that the device is functioning correctly.

•

Verify that the device is delivering biventricular pacing most

•

or all of the time.

Review the clinical performance and long term trends.

•

Print appropriate reports to compare the results to the

•

patient’s history and to retain for future reference.

For details about reviewing clinical trend data, see

Section 12.4, “Viewing the Heart Failure Management

•

report”, page 289

Patient follow-up guidelines

Section 12.5, “Viewing clinical trends in the Cardiac

•

Compass report”, page 293

Note: The Checklist feature displays a list of standard follow-up tasks on the programmer screen for easy reference during the follow-up session. You can also customize your own checklists if you wish. See Section 11.4, for more information.

5.2 Verifying the status of the implanted system

To verify that the device and leads are functioning correctly, review the following information from the Quick Look screen and perform follow-up tests as indicated:

Review the displayed battery voltage for comparison to the

•

Elective Replacement Indicator value (see Section 1.4, “Replacement indicators”, page 21). Remember that battery

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Chapter 5

Verifying effective cardiac resynchronization therapy

voltage may be low if high-voltage charging has occurred within 24 hours.

Review the last full-energy charge.

•

– For information about adjusting the capacitor formation

interval, see Section 9.1, “Optimizing charge time”, page 217.

– If the programmer displays an Excessive Charge Time

ERI, the device should be replaced immediately.

Review the deﬁbrillation and pacing lead impedance values

•

for inappropriate values or large changes since the last follow-up session. See Section 13.4, “Measuring lead impedance”, page 335.

Perform an EGM Amplitude test in the RV and atrium for

•

comparison to previous EGM amplitude measurements. See Section 13.5.5, “How to perform an EGM Amplitude test”, page 339.

To review longer term trends in sensing and impedance

•

measurements, select the [>>] button from the lead performance area of the Quick Look screen. The programmer displays a detailed history of automatic sensing and impedance measurements. See Section 11.2, “Taking a quick look at device activity”, page 264.

5.3 Verifying effective cardiac resynchronization therapy

To verify that the device is providing cardiac resynchronization therapy appropriately, review the following information from the initial interrogation report or Quick Look screen and investigate as indicated:

Conﬁrm that the patient is receiving adequate cardiac

•

support for daily living activities.

Review Quick Look Observations related to ventricular

•

pacing percentage or ventricular sensing episodes.

Check the stored Ventricular Sensing Episode records for

•

appropriate interventions and continuity of resynchronization pacing. See Section 12.7, “Viewing episode data”, page 305.

Check the rate histograms for more information on atrial and

•

ventricular pacing in general, and ventricular rates during AT/AF episodes.

INSYNC SENTRY®7299 Reference Manual

•

5.3.1 Considerations

Review the following information before assessing resynchronization therapy.

•

5Conducting a patient follow-up session

Verifying effective basic pacing

Review the Heart Failure Management and Cardiac Compass reports for comparison to patient history (see Section 12.4, “Viewing the Heart Failure Management report”, page 289, and Section 12.5, “Viewing clinical trends in the Cardiac Compass report”, page 293).

Undersensing, far-ﬁeld oversensing, or loss of capture are basic pacing issues that can affect delivery of cardiac resynchronization therapy. These situations can often be resolved with basic programming changes and then monitored for further occurrences.

If CRT delivery is lost during AF or during atrial rate excursions, consider the following programming options:

– Perform basic programming changes to increase the

Upper Tracking Rate or decrease the total atrial refractory period (for information on total atrial refractory period, see Section 8.2.4, “Programming considerations for atrial rates”, page 169).

– Enable Ventricular Sense Response, Atrial Tracking

Recovery, or Conducted AF Response to promote more continuous delivery of CRT.

5.4 Verifying effective basic pacing

To verify that the device is sensing and pacing appropriately, review the following information from the Initial Interrogation Report, and Quick Look screen, and investigate as indicated:

Conﬁrm that the patient is receiving adequate cardiac

•

support for daily living activities.

Review the pacing conduction history and rate histograms

•

for comparison to the patient history. A sharp increase in the atrial pacing percentage may indicate a need for investigation and analysis.

Review the recorded Mode Switch episodes for comparison

•

to the patient’s atrial arrhythmia history (see Section 12.7, “Viewing episode data”, page 305). A dramatic increase in frequency or duration of atrial episodes may indicate a need for investigation and analysis.

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Chapter 5

Verifying accurate detection and appropriate therapy for ventricular tachyarrhythmias

Review the Cardiac Compass report for comparison to

•

patient history (see Section 12.5, “Viewing clinical trends in the Cardiac Compass report”, page 293).

Conduct pacing threshold tests (see Section 13.3,

•

“Measuring pacing thresholds”, page 332) to verify that the programmed pacing outputs provide a sufﬁcient safety margin.

5.4.1 Considerations

Review the following information before verifying bradycardia pacing.

Atrial pacing – If the conduction history or rate histograms show a predominance of atrial pacing despite a healthy sinus response, consider these options to decrease the atrial pacing burden:

Decrease the Lower Rate.

•

Decrease the rate response or increase the activity

•

threshold.

Conduction history – If the reported percentages in the conduction history do not add up to 100, the percentages may be rounded.

5.5 Verifying accurate detection and appropriate therapy for ventricular tachyarrhythmias

To verify that the device is providing effective tachyarrhythmia detection and therapy, review the following information from the Quick Look screen and investigate as indicated:

Review Quick Look Observations that relate to patient history

•

and device operation. To display more detailed information about any observation, select the observation and then select the [>>] button.

Review any Patient Alerts listed in the Observations of the

•

Quick Look screen. For the most detailed information about Patient Alerts, select Patient Alert from the Data icon and select [System Events].

Check stored episode records for appropriate sensing

•

and detection of arrhythmias. See Section 12.7, “Viewing episode data”, page 305.

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•

5.5.1 Considerations

Review the following information before verifying detection and therapy.

Flashback memory – In addition to the episode text and stored electrograms, use Flashback memory and interval plots to help investigate the accuracy and speciﬁcity of ventricular detection.

Episode misidentiﬁcation – If the episode records indicate that false detections have occurred, the Sensing Integrity counter may help in determining the prevalence of oversensing. For more information, see Section 12.2.4.3, “Sensing integrity counter”, page 285.

If the device is oversensing, consider these programming options:

•

5Conducting a patient follow-up session

Verifying accurate detection and appropriate therapy for

ventricular tachyarrhythmias

Check stored SVT episode records for appropriate identiﬁcation of SVTs.

Increase the Pace Blanking value.

Increase the sensitivity threshold.

Caution: Do not reprogram the device to decrease oversensing without ensuring that appropriate sensing is maintained. See Section 6.2, “Setting up sensing”, page 78.

If the episode records reveal that a stable monomorphic VT has been identiﬁed and treated as VF, consider these options to improve the detection accuracy:

Review the Interval Plot for the episode, and adjust the VF

•

Interval, if necessary. Use caution when reprogramming the VF Interval, because changes to this value can adversely affect VF detection.

Consider enabling FVT via VF detection. See Section 6.5,

•

“Detecting FVT episodes”, page 92.

If the SVT episode records include episodes of true VT, review the SVT episode record to identify the SVT detection criterion that withheld detection. Adjust the SVT detection criteria parameters as necessary. See Section 6.8, “Enhancing detection with PR Logic criteria”, page 103, and Section 6.9, “Enhancing VT detection with the Stability criterion”, page 111.

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Conﬁguring the device for the patient

Part III

6Detecting tachyarrhythmias

6.1 Detection overview 75

6.2 Setting up sensing 78

6.3 Detecting VF episodes 83

6.4 Detecting VT episodes 86

6.5 Detecting FVT episodes 92

6.6 Detecting tachyarrhythmia episodes with Combined Count 97

6.7 Monitoring episodes for termination or redetection 99

6.8 Enhancing detection with PR Logic criteria 103

6.9 Enhancing VT detection with the Stability criterion 111

6.10 Detecting double tachycardias 113

6.11 Detecting prolonged tachyarrhythmias with High Rate Timeout 114

6.1 Detection overview

The device detects ventricular tachyarrhythmias (VF, VT, and FVT) by comparing the time intervals between sensed ventricular events to a set of programmable detection intervals. If enough intervals occur that are shorter than the programmed intervals, the device detects a tachyarrhythmia and responds automatically with a programmed therapy. After delivering the therapy, the device either redetects the arrhythmia and delivers the next programmed therapy or detects episode termination.

To avoid detecting rapidly conducted SVTs (for example, sinus tachycardia or atrial ﬁbrillation) as ventricular tachyarrhythmias, the device provides several detection enhancements, including PR Logic and Stability detection criteria.

All of the detection features interact during initial detection (see Figure 4). During redetection, the device does not apply the PR Logic detection criteria.

Note: Detection functions can be turned off by programming the VF Enable, FVT Enable, and VT Enable parameters to Off. For an example, see Section 6.3.4, “How to program VF detection”, page 85.

6Detecting tachyarrhythmias

Detection overview

INSYNC SENTRY®7299 Reference Manual

Ventricular Event

Yes

Update counts and pattern information

Is the interval in the VF, FVT, or VT detection zone?

Has High Rate Timeout suspended detection enhancements?

Does Stability reset the VT event count? (VT and FVT via VT

detection only)

Has a tachyarrhythmia event count reached an NID?

Are one or more PR Logic criteria on?

No/suspended by High Rate

Timeout

Tachy

Episode

Detected

Is the median ventricular interval less than the SVT Limit?

Is there a double tachycardia in progress?

Are one or more PR Logic criteria withholding detection?

Chapter 6

Detection overview

Figure 4. How detection features interact during initial detection

6.1.1 Suspending tachyarrhythmia detection

INSYNC SENTRY®7299 Reference Manual

When detection is suspended, the device temporarily stops classifying and counting tachyarrhythmia intervals. Sensing and programmed pacing remain active, and the programmed detection settings are not modiﬁed.

6Detecting tachyarrhythmias

Detection overview

Detection is suspended:

when the device senses the presence of a strong magnet.

•

The programmer head contains a magnet which suspends detection, but once telemetry between the device and programmer is established, detection resumes.

while performing any of the manual system tests, including

•

Underlying Rhythm, Pacing Threshold, Lead Impedance, EGM Amplitude, and Charge/Dump. Detection automatically resumes once the test is complete.

while performing a T-Shock, 50 Hz Burst, Manual Burst,

•

or PES Induction. You can choose to have the device automatically resume detection after delivering the induction.

when you deliver a Manual or Emergency therapy. You

•

can resume detection by selecting the [Resume] button or removing the programming head from the device.

when you select the on-screen [Suspend] button. You can

•

resume detection by selecting the [Resume] button or by removing the programming head from the device.

during the automatic daily lead impedance measurements.

•

Detection resumes when the measurements are complete.

while the device is delivering an automatic tachyarrhythmia

•

therapy (including capacitor charging for deﬁbrillation and cardioversion). However, the device does continue to conﬁrm the detected episode during charging. Detection resumes when the therapy is complete.

Note: The device suspends VT detection and Combined Count detection (see Section 6.6, “Detecting tachyarrhythmia episodes with Combined Count”, page 97) for 17 events following a deﬁbrillation therapy delivered in response to a detected VF.

during charging for Automatic Capacitor Formation.

•

Detection resumes when charging is complete.

If the deﬁbrillation therapy is delivered as a result of either a High Rate Timeout Therapy operation or Progressive Episode Therapies operation, VT detection is not suspended (see Section 6.11.4.1, “High Rate Timeout Therapy”, page 116).

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Chapter 6

Setting up sensing

6.2 Setting up sensing

The device provides bipolar sensing in both the atrium and right ventricle using the sensing electrodes of the implanted atrial and RV leads. You can adjust the sensitivity to intracardiac signals using independent atrial and ventricular sensitivity settings. These settings deﬁne the minimum electrical amplitude recognized by the device as an atrial or ventricular sensed event.

Proper sensing is essential for the safe and effective use of the device. To provide appropriate sensing, the device uses:

auto-adjusting atrial and ventricular sensing thresholds

•

short (30 ms) cross-chamber blanking after paced events

•

no cross-chamber blanking after sensed events

•

See Section 6.2.4, “Details about sensing”, page 80.

6.2.1 Parameters

V. Sensitivity – Minimum amplitude of

electrical signal that registers as a sensed ventricular event.

A. Sensitivity – Minimum amplitude of electrical signal that registers as a sensed atrial event.

6.2.2 Considerations

Review the following information before programming sensing parameters.

Dual chamber sensing and pacing modes – The device senses in both the atrium and the right ventricle at all times, except when the programmed bradycardia pacing mode is DOO. When the pacing mode is programmed to DOO or VOO mode, there is no sensing in the ventricle. mode, you must ﬁrst disable detection.

Sensitivity thresholds – The programmed atrial and ventricular sensitivity thresholds apply to all features related to sensing, including detection and bradycardia pacing.

Atrial sensing occurs in VOO mode.

0.15; 0.3

0.9; 1.2 mV

0.15; 0.3

0.9; 1.2; 1.5; 2.1 mV

In order to program either DOO or VOO

; 0.45; 0.6;

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6Detecting tachyarrhythmias

Setting up sensing

Bradycardia pacing and sensing – A combination of high pacing pulse width or high amplitude with a low sensitivity threshold may cause inappropriate sensing across chambers or in the same chamber. Programming a lower pulse width, lower amplitude, longer pace blanking, or a higher sensitivity threshold may eliminate this inappropriate sensing.

Recommended ventricular sensitivity threshold – A ventricular sensitivity threshold of 0.3 mV is recommended to maximize the probability of detecting VF and to limit the possibility of oversensing and cross-chamber sensing.

High ventricular sensitivity threshold – Setting V. Sensitivity to a value greater than 0.6 mV is not recommended except for testing. Doing this may cause undersensing, which can cause any of the following situations:

delayed or aborted cardioversion therapy

•

delayed deﬁbrillation therapy (when VF conﬁrmation is

•

active)

asynchronous pacing

•

underdetection of tachyarrhythmias

•

Low ventricular sensitivity threshold – If you set V. Sensitivity to its most sensitive value of 0.15 mV, the device will be more susceptible to EMI, cross-chamber sensing, and oversensing.

Recommended atrial sensitivity threshold – An atrial sensitivity threshold of 0.3 mV is recommended to optimize the effectiveness of PR Logic detection criteria and atrial pacing operations, while limiting the possibility of oversensing and cross-chamber sensing.

High atrial sensitivity threshold – If you set the A. Sensitivity value too high, the device may not provide reliable sensing of P-waves during SVTs and sinus rhythm.

Low atrial sensitivity threshold – If you set the A. Sensitivity value to its most sensitive value of 0.15 mV, the device will be more susceptible to EMI, far-ﬁeld R-wave sensing, and oversensing.

Testing sensitivity after reprogramming – If you change the ventricular sensitivity threshold, evaluate for proper sensing and detection by inducing VF and allowing the device to automatically detect and treat the arrhythmia.

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Chapter 6

Setting up sensing

Atrial pacing and ventricular sensing – If you program the device to an atrial pacing mode, make sure that it does not sense atrial pacing pulses as ventricular events.

Sensing during VF – Always verify that the device senses properly during VF. If the device is not sensing or detecting properly, program detection and therapies off, and evaluate the system (making sure to monitor the patient for life-threatening arrhythmias until you enable detection and therapies again). You may need to reposition or replace the ventricular sensing lead to achieve proper sensing.

Atrial lead selection – Atrial leads with minimal tip-to-ring spacing may reduce far-ﬁeld R-wave sensing.

Repositioning the atrial lead – You may need to reposition or replace the atrial sensing lead if reprogramming the atrial sensitivity threshold does not provide reliable atrial sensing during SVTs and sinus rhythm.

6.2.3 How to program sensitivity

1. Select Params > Detection.

2. Select the desired A. Sensitivity and V. Sensitivity parameters.

3. Select [PROGRAM].

6.2.4 Details about sensing

6.2.4.1 Auto-adjusting sensitivity thresholds

The device automatically adjusts the sensitivity thresholds after certain paced and sensed events to help reduce oversensing from T-waves, cross-chamber events, and pacing. You can see

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6Detecting tachyarrhythmias

A P

V S

A S

V P

Sensitivity Threshold

Rectified and

Filtered A. EGM

Rectified and

Filtered RV EGM

Marker Channel

1 2

Setting up sensing

how sensitivity thresholds are adjusted after different types of events (see Figure 5).

Figure 5. Auto-adjusting sensitivity thresholds

1 After an atrial sensed event, the atrial sensitivity threshold increases

to 75% of the EGM peak (maximum: 8x the programmed value, decay constant: 200 ms).

2 After a ventricular sensed event, the ventricular sensitivity threshold

increases to 75% of the EGM peak (maximum: 8x the programmed value, decay constant: 450 ms).

3 After an atrial paced event, the device does not adjust the atrial

sensitivity threshold. The ventricular sensitivity threshold increases by 0.45 mV (decay constant: 60 ms).

4 After a ventricular paced event, the atrial sensitivity threshold

increases to 4x the programmed value (maximum: 1.8 mV, immediate return after 60 ms).

5 After the ventricular pace blanking period is ﬁnished, the ventricular

threshold increases to 4.5x the programmed value (maximum:

1.8 mV, decay constant: 450 ms).

6.2.4.2 Blanking periods

During a blanking period, the device does not sense electrical signals. This helps prevent sensing of device pacing, cardioversion and deﬁbrillation pulses, post-pacing depolarization, T-waves, and multiple sensing of the same event.

The exponential decay continues through a subsequent ventricular pacing pulse and its blanking period.

If the programmed sensitivity value exceeds 0.3 mV (ventricular) or 1.2 mV (atrial), the threshold is not adjusted.

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Chapter 6

Setting up sensing

The blanking periods following paced events are longer than those following sensed events to avoid sensing the atrial and ventricular depolarizations.

Notes:

To enhance sensing and detection during tachyarrhythmias,

•

the device does not apply cross-chamber blanking (blank sensing in the opposite chamber) after a sensed event.

Atrial sensing is still active during the Post-Ventricular

•

Atrial Blanking (PVAB) period (see Section 8.2.3.5, “Post-Ventricular Atrial Refractory Period”, page 167).

The duration of the ﬁxed blanking periods is shown in Table 12. For information on programmable pace blanking periods, see Section 8.1, “Providing basic pacing therapy”, page 153.

Table 12. Duration of ﬁxed blanking periods

Cross-chamber blanking after atrial or ventricular pacing pulse

Atrial blanking after sensed atrial event

Ventricular blanking after sensed ventricular event

Atrial and ventricular blanking after delivered cardioversion or deﬁbrillation therapy

30 ms

100 ms

120 ms

520 ms

6.2.4.3 Refractory periods

During a refractory period, the device senses normally, but classiﬁes sensed events as refractory and limits its response to these events. Pacing refractory periods prevent inappropriately sensed signals, such as far-ﬁeld R-waves (ventricular events sensed in the atrium) or electrical noise, from triggering certain pacing timing intervals.

Synchronization refractory periods help prevent the device from delivering cardioversion and deﬁbrillation therapies at inappropriate times. See Section 7.1.5.5, “Synchronizing deﬁbrillation without conﬁrming VF”, page 123, and Section 7.3.5.6, “Synchronizing cardioversion after charging”, page 143.

Note: Refractory periods do not affect tachyarrhythmia detection.

INSYNC SENTRY®7299 Reference Manual

6.3 Detecting VF episodes

The device detects VF episodes by examining the cardiac rhythm for short ventricular intervals. If a predetermined number of intervals occur that are short enough to be considered VF events, the device detects VF and delivers the ﬁrst programmed VF therapy. After therapy, the device continues to evaluate the ventricular rhythm to determine if the episode is ongoing.

See Section 6.3.5, “Details about VF detection”, page 85.

6.3.1 Parameters

VF Detection Enable – Turns VF

detection on or off.

VF Interval (Rate) – V-V intervals shorter than this value are counted as VF events.

VF Initial NID – Number of Intervals to Detect: number of VF events the device must count to detect a VF episode.

VF Redetect NID – Number of Intervals to Redetect: number of VF events the device must count to redetect a continuing VF after a therapy.

6Detecting tachyarrhythmias

Detecting VF episodes

; Off

240; 250 … 320 400 ms

12/16; 18/24 30/40; 45/60; 60/80; 75/100; 90/120; 105/140; 120/160

6/8; 9/12; 12/16 21/28; 24/32; 27/36; 30/40

…

; 24/32;

; 18/24;

6.3.2 Considerations

Review the following information before programming VF Detection parameters.

VF Interval minimum setting – To ensure proper VF detection, you should not program the VF Interval to a value less than 300 ms.

VF Interval maximum setting – Programming the VF Interval to a value greater than 350 ms may cause inappropriate detection of rapidly conducted atrial ﬁbrillation as VF or FVT via VF. Intervals shorter than the VF Interval are counted using the VF event counter, which is more sensitive than the consecutive VT event counter.

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Chapter 6

Detecting VF episodes

VF, FVT, and VT Intervals – To allow for normal variations in the patient’s tachycardia interval, you should program the VF, FVT, and VT intervals at least 40 ms apart.

Episode redetection – You can expedite redetection by programming the VF and VT Redetect NIDs lower than the Initial NIDs.

Enabling VF detection – When VF Detection Enable is programmed On for the ﬁrst time, the device:

enables Automatic Capacitor Formation

•

starts recording Cardiac Compass data and Heart Failure

•

Management data

starts recording lead performance trends (starting at

•

3:00 AM by the device clock)

clears all brady pacing counters

•

VF detection and PR Logic criteria – You can program the device to exclude rapidly conducted SVTs from VF Detection by enabling the PR Logic detection criteria. Note that the SVT Limit must be programmed shorter than the VF Interval in order for the PR Logic criteria to affect VF detection. See Section 6.8, “Enhancing detection with PR Logic criteria”, page 103.

Double tachycardia detection – When any PR Logic detection criteria are enabled, the device also enables double tachycardia detection (VF, VT, or FVT in the presence of an SVT). See Section 6.10, “Detecting double tachycardias”, page 113.

6.3.3 Restrictions

Review the following information before programming VF Detection parameters.

Tachyarrhythmia detection and pacing – To ensure reliable ventricular tachyarrhythmia detection, the programmer regulates the values available for pacing and tachyarrhythmia detection. See Section B.11, “Parameter interlocks”, page 402.

VF detection backup – To ensure VF Detection backup during VT and FVT episodes, if VF Detection is off, both VT Detection and FVT Detection must also be off.

INSYNC SENTRY®7299 Reference Manual

6.3.4 How to program VF detection

6.3.5 Details about VF detection

The device detects VF by counting the number of VF events, which are V-V intervals shorter than the programmed VF Interval. On each event, the device counts the number of recent VF events. The number of recent events that are examined is called the VF detection window. The size of the VF detection window is the second number in the programmed VF NID (for example, 24 events if the VF Initial NID is 18/24).

6Detecting tachyarrhythmias

Detecting VF episodes

1. Select Params > Detection.

2. Select the desired values for VF Enable, VF Initial NID, VF Redetect NID, and VF Interval.

3. Select [PROGRAM].

The threshold for detecting VF is the ﬁrst number in the programmed VF NID (for example, 18 events if the VF Initial NID is 18/24). This threshold is always 75% of the VF detection window. That is, if 75% of the events in the VF detection window are VF events, the device detects a VF episode (see Figure 6).

After the device detects VF, it delivers the ﬁrst programmed VF therapy. Following the therapy, if the number of VF events reaches the programmed VF Redetect NID, the device redetects VF and delivers the next programmed VF therapy.

Note: The device can also detect VF Episodes using the Combined Count detection criterion (see Section 6.6).

INSYNC SENTRY®7299 Reference Manual

A S

V SV SV

V S

V SV

V S

A R

1 2 3 4 5 6 6 7 8 9 10 11 12 13 14 15 1617 18

F SF SF SF SF SF SF SF SF SF

F SF SF

F S

F D

200 ms

2 31

VF Event Count

ECG

Marker Channel

VF Interval

Chapter 6

Detecting VT episodes

Figure 6. Device detects VF

1 VF starts, and the device begins counting VF events (intervals less

than the programmed VF Interval).

2 A ventricular interval occurs outside the VF detection zone. The VF

event count is not incremented.

3 The VF event count reaches the programmed VF NID value of 18

events out of 24, and the device detects VF.

6.4 Detecting VT episodes

The device detects VT episodes by examining the cardiac rhythm for short ventricular intervals. If enough intervals occur that are short enough to be considered VT events (but are not VF or FVT events), the device detects VT and delivers the ﬁrst programmed VT therapy. After therapy, the device continues to evaluate the ventricular rhythm to determine if the episode is ongoing.

You can program the device to detect and record VT episodes without treating them with VT therapies by setting VT Detection Enable to Monitor. If a patient’s VT episodes are well-tolerated, this feature allows you to collect data about these episodes without delivering therapy or affecting VF detection.

INSYNC SENTRY®7299 Reference Manual

See Section 6.4.5, “Details about VT detection”, page 88.

6.4.1 Parameters

6Detecting tachyarrhythmias

Detecting VT episodes

VT Detection Enable – Turns VT detection on or off, or enables VT monitoring.

VT Interval (Rate) – V-V intervals shorter than this value are counted as VT events.

VT Initial NID – Number of Intervals to Detect: number of VT events the device must count to detect a VT episode.

VT Redetect NID – Number of Intervals to Redetect: number of VT events the device must count to redetect a continuing VT after a therapy.

6.4.2 Considerations

Review the following information before programming VT Detection parameters.

VF, FVT, and VT Intervals – To allow for normal variations in the patient’s tachycardia interval, you should program the VF, FVT, and VT intervals at least 40 ms apart.

Episode redetection – You can expedite redetection by programming the VF and VT Redetect NIDs lower than the Initial NIDs.

On; Off

280; 290 … 400

12; 16

4; 8; 12

; Monitor

…52; 76; 100

… 52

… 600 ms

VT Detection Enable, AFib/AFlutter, and Sinus Tach – When you set VT Detection Enable to On or Monitor, the AFib/AFlutter and Sinus Tach parameters are also automatically set to On.

VT detection and Combined Count detection – When VT Detection is On, the device applies the Combined Count detection criterion to help speed detection of rhythms that ﬂuctuate between detection zones. Combined Count detection is disabled if VT Detection is set to Off or Monitor. See Section 6.6, “Detecting tachyarrhythmia episodes with Combined Count”, page 97.

VT detection and rapidly conducted SVTs – You can program the device to exclude rapidly conducted SVTs from VT detection by enabling the PR Logic or Stability detection criteria. See Section 6.9, “Enhancing VT detection with the Stability criterion”,

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Chapter 6

Detecting VT episodes

page 111, and Section 6.8, “Enhancing detection with PR Logic criteria”, page 103.

Double tachycardia detection – When any PR Logic detection criteria are enabled, the device also enables double tachycardia detection (VF, VT, or FVT in the presence of an SVT; see Section 6.10).

6.4.3 Restrictions

Review the following information before programming VT detection parameters.

VF detection backup – To ensure VF detection backup during VT and FVT episodes, if VF Detection is off, both VT Detection and FVT Detection must also be off.

6.4.4 How to program VT detection

1. Select Params > Detection.

2. Select the desired values for VT Enable, VT Initial NID, VT Redetect NID, and VT Interval.

3. Select [PROGRAM].

6.4.5 Details about VT detection

INSYNC SENTRY®7299 Reference Manual

The device detects VT by counting the number of consecutive VT events. A VT event is a V-V interval shorter than the programmed VT Interval but greater than or equal to the VF Interval. If the

6Detecting tachyarrhythmias

Detecting VT episodes

number of consecutive VT events reaches the programmed VT Initial NID, the device detects VT (see Figure 7).

The VT event count resets to zero whenever an interval occurs that is greater than or equal to the programmed VT Interval. The count remains at the current value if an interval is shorter than the programmed VF Interval.

After the device detects VT, it delivers the ﬁrst programmed VT therapy. Following the therapy, if the VT event counter reaches the VT Redetect NID, the device redetects VT and delivers the next programmed therapy.

Note: The device can also detect VT Episodes using the Combined Count detection criterion (see Section 6.6, “Detecting tachyarrhythmia episodes with Combined Count”, page 97).

INSYNC SENTRY®7299 Reference Manual

A S

V SV

V S

A RA RA RA RA RA RA

1 0 1 2 3 4 5 6

T S

T ST ST ST ST ST

V S

A RA RA RA RA RA RA RA RA RA RA RA

7 8 9 10 11 12 13 14 15 16

200 ms

T ST ST ST ST ST ST ST ST

T D

VT Event Count

ECG

Marker Channel

VT Interval

VT Event Count

ECG

Marker Channel

VT Interval

Chapter 6

Detecting VT episodes

Figure 7. Device detects VT

1 VT starts, and the device begins counting VT events (intervals less

than the programmed VT Interval but greater than or equal to the VF Interval).

2 A ventricular interval occurs outside VT detection zone. The VT event

count resets to zero.

3 The VT event count reaches the programmed VT NID of 16 events,

and the device detects VT.

6.4.5.1 VT monitoring

You can program the device to record VT episodes without delivering VT therapy by setting VT Detection to Monitor. When VT monitoring is enabled, the device detects VT episodes but does not deliver VT therapy (see Figure 8). Instead, it records VT episodes, labeling them as “monitored,” and waits for episode termination to occur.

When VT Detection is set to Monitor, several detection operations work differently.

INSYNC SENTRY®7299 Reference Manual

VT event counting – Before the device detects an episode, it counts VT events normally. However, once the VT Initial NID is

6Detecting tachyarrhythmias

Detecting VT episodes

reached, the device sets the VT event count to zero and suspends VT event counting for the rest of the episode.

VF and FVT detection – VF and FVT detection operate as if VT detection is off. Speciﬁcally, Combined Count detection is disabled, and FVT via VT detection is not selectable. If a monitored VT episode accelerates into the FVT or VF detection zone, the device applies the VF Initial NID to detect the new tachyarrhythmia. Once an episode is in progress, VT event counting doesn’t resume until the episode ends.

Caution: Programming the VF Interval greater than 350 ms may result in inappropriate detection of rapidly conducted atrial ﬁbrillation as VF or FVT via VF. Intervals shorter than the VF Interval are counted using the VF event counter, which is more sensitive than the consecutive VT event counter.

PR Logic and Stability criteria – Before the device detects a tachyarrhythmia episode, the PR Logic and Stability criteria, if turned on, are applied. If a monitored VT episode accelerates into the FVT or VF detection zone, the device continues to apply PR Logic criteria as initial VF or FVT detection begins. However, because the Stability feature does not affect VF detection or FVT via VF detection, it is not applied.

Episode termination – The device compares ventricular intervals to the VT Interval to identify when a VT monitored episode has ended. However, if a VF episode or FVT via VF episode occurs when VT monitoring is enabled, the device compares ventricular intervals to the VF Interval to identify episode termination.

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200 ms

1 2 3 4

A S

A R

A RA RA

V S

V ST ST ST ST

13 14 15 16 0 0 0

A R

A RA RA RA RA

T ST ST ST DT ST ST

2 31

VT Event Count

ECG

Marker Channel

VT Interval

Chapter 6

Detecting FVT episodes

Figure 8. Device detects and monitors VT

1 VT starts, and the device begins counting VT events (intervals less

than the programmed VT Interval but greater than or equal to the VF Interval).

2 The VT event count reaches the programmed VT NID of 16 events,

and the device detects VT.

3 After detecting the VT episode, the device resets the VT event count

to zero and monitors the episode until termination.

6.5 Detecting FVT episodes

The device detects episodes of Fast Ventricular Tachycardia (FVT) by examining the cardiac rhythm for short ventricular intervals. If enough intervals occur in the programmed FVT detection zone, the device detects FVT and delivers the ﬁrst programmed FVT therapy. After therapy, the device continues to evaluate the ventricular rhythm to determine if the episode is ongoing. To make sure it delivers sufﬁciently aggressive therapies, the device can merge the programmed detection zones during redetection to increase sensitivity.

INSYNC SENTRY®7299 Reference Manual

See Section 6.5.5, “Details about FVT detection”, page 95.

6.5.1 Parameters

FVT Detection Enable – Enables FVT

detection via the VF or the VT detection algorithm.

FVT Interval (Rate) – V-V intervals between this value and the programmed VF Interval are marked as FVT events.

6.5.2 Considerations

Review the following information before programming FVT Detection parameters.

VF, FVT, and VT Intervals – To allow for normal variations in the patient’s tachycardia interval, you should program the VF, FVT, and VT intervals at least 40 ms apart.

Episode redetection – You can expedite redetection by programming the VF and VT Redetect NIDs lower than the Initial NIDs.

6Detecting tachyarrhythmias

Detecting FVT episodes

; via VF; via VT

Off

200; 210 … 600 ms

FVT detection enable – Your choice for an appropriate setting for FVT Detection should depend on the patient’s VF and VT cycle lengths. After determining a reliably sensitive VF Interval, consider the following suggestions:

If the patient presents with a clinical VT interval in the VF

•

zone, select via VF to ensure reliable detection of VF. (VT Detection need not be enabled at all.)

If the patient presents with 2 clinical VTs, both outside the

•

VF zone, select via VT to allow for correct classiﬁcation of the faster VT and to offer a separate therapy regimen for each VT.

If the patient presents with only 1 clinical VT, which is outside

•

the VF zone, select VF and VT Detection only, and set FVT Enable to Off.

FVT detection and PR Logic criteria – You can program the device to exclude rapidly conducted SVTs from FVT Detection by enabling the PR Logic detection criteria. Note that the SVT Limit must be programmed shorter than the VF Interval for the PR Logic criteria to affect FVT via VF detection.

INSYNC SENTRY®7299 Reference Manual

Chapter 6

Detecting FVT episodes

6.5.3 Restrictions

Double tachycardia detection – When any PR Logic detection

criterion is enabled, the device also enables double tachycardia detection (VF, VT, or FVT in the presence of an SVT, see Section 6.10).

Review the following information before programming FVT Detection parameters.

Tachyarrhythmia detection and bradycardia pacing – To ensure reliable ventricular tachyarrhythmia detection, the programmer regulates the values available for bradycardia pacing and tachyarrhythmia detection. See Section B.11, “Parameter interlocks”, page 402.

VF detection backup – To ensure VF Detection backup during VT and FVT episodes, VT and FVT Detection cannot be on unless VF Detection is also on.

FVT detection – To ensure reliable ventricular tachyarrhythmia detection, the programmer regulates the values available for the FVT parameter as follows:

VT Detection must be set to On if FVT Detection is set to

•

via VT.

If FVT Detection is set to via VF, the FVT Interval must be

•

programmed to a value shorter than the VF Interval.

If FVT Detection is set to via VT, the FVT Interval must be

•

programmed to a value greater than the VF Interval and less than or equal to the VT Interval.

INSYNC SENTRY®7299 Reference Manual

6.5.4 How to program FVT detection

6.5.5 Details about FVT detection

You can program the device to detect FVT episodes via the VF or VT detection zone and NID.

6Detecting tachyarrhythmias

Detecting FVT episodes

1. Select Params > Detection.

2. Select the desired values for FVT Enable and FVT Interval.

3. Select [PROGRAM].

When FVT Detection is set to via VF, a V-V interval within the FVT detection zone is marked as an “FVT via VF” event. When the VF NID is reached, the device reviews the last 8 intervals:

If any of the last 8 intervals are in the VF zone, it detects

•

the episode as VF.

If all of the last 8 intervals are outside the VF zone, it detects

•

the episode as FVT (see Figure 9).

When FVT Detection is set to via VT, a V-V interval within the FVT detection zone is marked as an “FVT via VT” event. When the VT NID is reached, the device reviews the last 8 intervals:

If any of the last 8 intervals are in the VF or FVT zones, it

•

detects the episode as FVT.

If all of the last 8 intervals are outside the FVT and VF zones,

•

it detects the episode as VT.

Note: The device can also detect FVT episodes via the Combined Count detection criterion (see Section 6.6).

INSYNC SENTRY®7299 Reference Manual

200 ms

13 14 15 16 17 18

A RA RA RA RA RA RA RA RA

T FT

T FT FT FT FT FV

1 1 2 3 4 5

A S

A RA RA

A R

V S

T S

T F

T FT FT FT

1 2

VF Event Count

ECG

Marker Channel

VF and FVT Intervals

Chapter 6

Detecting FVT episodes

Figure 9. Device detects FVT via VF

1 A fast ventricular tachycardia starts, and the ﬁrst event falls into the

FVT detection zone.

2 The second event of the FVT episode has an interval that falls into

the VT zone. The VF event count is not incremented.

3 The device detects FVT after the VF event count reaches the VF

Initial NID.

6.5.5.1 Zone merging after detection

To ensure that the device delivers sufﬁciently aggressive therapies during an extended or highly variable tachyarrhythmia episode, the device merges detection zones during redetection in some instances, as shown in Figure 10. The merged zone conﬁguration uses the event counting and therapies for the faster arrhythmia and remains in effect until episode termination.

INSYNC SENTRY®7299 Reference Manual

Figure 10. FVT zone merging

Before detection

After VF detection

After FVT detection

FVT set to “via VF”

VF and FVT zones merge, leaving a larger VF zone.

All zones remain unchanged.

FVT set to “via VT”

VT and FVT zones merge, leaving a larger FVT zone.

Detection Intervals: VF Interval: 320 ms, FVT Interval: 280 ms / 360 ms, VT Interval: 400 ms

FVT

6Detecting tachyarrhythmias

Detecting tachyarrhythmia episodes with Combined Count

6.6 Detecting tachyarrhythmia episodes with Combined Count

Because the device counts VF and VT events separately, rhythms with variable cycle lengths can cause both event counts to increment during an episode. To prevent these rhythms from delaying detection, the device automatically enables the Combined Count detection criterion if both VF and VT detection are programmed On.

The Combined Count criterion compares the sum of the VF and VT event counts to the Combined Number of Intervals to Detect (CNID), which the device calculates automatically from the programmed VF NID values. If the CNID is met, the device reviews the recent intervals to determine if the episode should be treated as a VF, FVT, or VT episode. The Combined Count criterion applies during both initial detection and redetection.

INSYNC SENTRY®7299 Reference Manual

Chapter 6

Detecting tachyarrhythmia episodes with Combined Count

6.6.1 Details about Combined Count detection

The Combined Count detection algorithm expedites detection or redetection of ventricular tachyarrhythmias with ventricular intervals that ﬂuctuate between the VF and VT detection zones. When VT detection is on, the device applies Combined Count detection, which tracks the combined number of VT and VF events counted. If this sum reaches the Combined Number of Intervals to Detect (CNID), the device detects VF, FVT, or VT. Combined Count detection also applies to redetected episodes.

Note: Combined Count detection is off when VT detection is set to Monitor or Off.

If the VF event counter reaches 6, the device automatically applies the Combined Number of Intervals to Detect (CNID). The CNID is calculated by multiplying the current VF NID (Initial or Redetect) by 7/6 and rounding down. Table 13 shows the CNID values that correspond to each VF NID value.

Table 13. CNID values for each initial or redetect VF NID value

VF NID CNID VF NID CNID

6/8

9/12

12/16

18/24

21/28

24/32

27/36

30/40

Combined Count detection is fulﬁlled when the sum of the VF and VT event counts equals or exceeds the CNID. The device then reviews the last 8 intervals and classiﬁes the episode as one of the following:

VF, if any of the last 8 were in the VF zone

•

FVT, if FVT Detection is enabled and none of the last 8 was

•

in the VF zone, but one or more was in the FVT zone

VT, if all 8 were outside the VF zone (and FVT zone, if FVT

•

detection is enabled)

INSYNC SENTRY®7299 Reference Manual

Monitoring episodes for termination or redetection

200 ms

A SA RA RA RA RA RA RA RA RA RA RA RA

A R

V SV SF

F S

F SF SF SF SF SF ST SF SF SF SF SF SF SF SF

F S

T ST

F DV

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

1 2 3 4

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

VF Event Count

VT Event Count

Combined Count

VF and VT Interval

ECG

Marker Channel

1 2 3

Figure 11. Device detects VF with the Combined Count criterion

1 A slow VF episode starts with a ventricular cycle length that varies

between the VF and VT detection zones.

2 When a VT event occurs, the device increments the VT event count

and the Combined Count.

3 The device detects VF even though the VF event count hasn’t yet

reached the VF Initial NID (18/24 in this example). The Combined Count reaches the CNID value of 21 ﬁrst.

6Detecting tachyarrhythmias

6.7 Monitoring episodes for termination or redetection

Once the device detects an arrhythmia, it considers the episode ongoing until it detects that the episode has ended. After delivering therapy, it monitors the ventricular rhythm using the programmed Redetect NIDs. If one of these NIDs is met, the device delivers the next programmed therapy for the detected arrhythmia.

See Section 6.7.4, “Details about episode termination and redetection”, page 100.

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100

Chapter 6

Monitoring episodes for termination or redetection

6.7.1 Parameters

VF Redetect NID – Number of Intervals

to Redetect: number of VF events the device must count to redetect a continuing VF after a therapy.

VT Redetect NID – Number of Intervals to Redetect: number of VT events the device must count to redetect a continuing VT after a therapy.

6.7.2 Considerations

Review the following information before programming redetection parameters.

Initial and Redetect NIDs – You can expedite redetection by programming the VF and VT Redetect NIDs lower than the Initial NIDs.

6.7.3 How to program redetection parameters

6/8; 9/12; 12/16 21/28; 24/32; 27/36; 30/40

4; 8; 12

1. Select Params > Detection.

2. Select the desired values for VT Redetect NID and VF Redetect NID.

3. Select [PROGRAM].

… 52

; 18/24;

6.7.4 Details about episode termination and redetection

INSYNC SENTRY®7299 Reference Manual

After a therapy is delivered, the device evaluates the ventricular rhythm to determine if the episode has terminated, is continuing, or has changed to a different arrhythmia.

Medtronic 7299 Reference Guide

Specifications and Main Features

Frequently Asked Questions

User Manual

Contents

Introduction

Using this manual

Manual conventions

Technical support

References

Notice

Part I

1Quick reference

1.1 Physical characteristics

Table 2. Lead connections

Figure 1. Lead connections

Figure 2. Suture holes

1.2 Magnet application

Table 3. Effects of magnet application on the device

1.3 Projected longevity

Table 4. Projected longevity in years

1.4 Replacement indicators

Table 5. Replacement indicators

1.5 Typical charge times

1.6 High-voltage therapy energy

Table 7. Comparison of delivered (programmed) and stored energy levels

1.7 Stored data and diagnostics

Table 8. Stored data and diagnostics

1.8 New and enhanced features

1.8.1 Patient management

1.8.2 Tachyarrhythmia therapy

1.8.3 Cardiac resynchronization therapy

2The InSync Sentry system

2.1 System overview

2.1.1 Cardiac resynchronization

2.1.2 Detecting and treating tachyarrhythmias

2.1.3 Treating bradycardia

2.1.4 Monitoring for real-time and stored data

2.1.5 Conducting electrophysiologic tests

2.1.6 Alerting the patient to system events

2.2 Indications and usage

2.3 Contraindications

2.4 Patient screening

3Emergency therapy

3.1 Delivering emergency therapies

3.1.1 Effect on system operation

3.1.2 Aborting an emergency therapy

3.1.3 Mechanical Emergency VVI button on the Medtronic CareLink Model 2090 programmer

3.1.4 Temporary parameter values

3.3 Delivering an emergency cardioversion therapy

3.3.1 How to deliver emergency cardioversion

3.5 Enabling emergency VVI pacing

3.5.1 How to deliver emergency VVI pacing

Part II

4Implanting the device

4.1 Implant overview

4.2 Preparing for an implant

4.2.1 Equipment for an implant

4.2.2 Sterile supplies

4.2.3 How to set up the implant support instrument

4.2.4 How to set up the programmer and start the application

4.2.5 How to preprogram the device

4.3 Replacing a device

4.3.1 How to explant and replace a device

4.4 Surgical approach

4.4.1 Implanting the device

4.4.3 Implanting the lead

4.4.3.1 Implanting the ventricular leads

4.4.3.2 Implanting the right atrial lead

4.4.3.3 Lead positioning

4.4.4 Using other transvenous leads

4.4.5 Using epicardial lead systems

4.5 Sensing and pacing measurements

Table 9. Acceptable implant values

4.6 Connecting the leads to the device

Table 10. Lead connections

Figure 3. Device ports for lead connections

4.6.1 How to connect the lead to the device

4.6.2 Post pace oversensing testing

4.7.1 High-voltage implant values