Medtronic 7274 Reference Guide

MARQUIS

Dual Chamber Implantable Cardioverter Defibrillator

™

DR 7274

Reference Manual

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

MARQUIS DR 7274

Reference Manual

A guide to the operation and programming of the Model 7274 Marquis DR Dual Chamber Implantable Cardioverter Defibrillator

The following are trademarks of Medtronic:

Active Can

, Cardiac Compass, Checklist, Decision Channel, Flashback®, GEM®, Leadless™ ECG, Marker Channel, MARQUIS, Patient Alert, PR Logic, Quick Look, QuickLink, RapidRead, T-Shock

Table of contents

Introduction xv

Using this manual xv Contacting technical support xv Customer education xv References xvi Notice xvi

Abbreviations and acronyms xvii

Part I Quick overview

1 Quick reference 3

Physical characteristics 4

Magnet application 5

Longevity projections 6

Replacement indicators 8

Typical charge times 10

High voltage therapy energy 10

Stored data and diagnostics 11

New and enhanced features 14

Patient management 14 Tachyarrhythmia detection 15 Tachyarrhythmia therapy 16 Bradycardia pacing 16 EP studies 17

2 The Marquis DR system 19

System overview 20

Detecting and treating tachyarrhythmias 21 Treating bradycardia 22 Monitoring for real-time and stored data 22 Conducting electrophysiologic tests 22 Alerting the patient to system events 22

Indications and usage 23

Contraindications 23

Patient screening 23

Marquis DR 7274 Reference Manual

Table of contents

3 Emergency therapy 25

Delivering emergency therapies 26

Effect on system operation 26 Aborting an emergency therapy 26 On-screen and display panel buttons 27 Temporary parameter values 27 How to deliver emergency 30 joule defibrillation 28 How to deliver emergency cardioversion 28 How to deliver emergency fixed burst pacing 29 How to deliver emergency VVI pacing 30

Part II Device implant and patient follow-up procedures

4 Implanting the ICD 33

Overview 34

Preparing for an implant 34

Equipment for an implant 34 Sterile supplies 35 How to prepare for implanting 35

Replacing an ICD 36

How to explant and replace an ICD 37

Positioning the leads 37

Using transvenous leads 37 Using epicardial leads 38 Surgical incisions 39

Testing sensing and pacing thresholds 39

Parameters 40 Considerations 40

Connecting the leads to the ICD 40

How to connect the lead to the device 41

Testing defibrillation operation and effectiveness 42

High voltage implant values 42 Binary search protocol 43 How to prepare for defibrillation threshold testing 44 How to perform defibrillation threshold testing 45

Positioning and securing the ICD 46

How to position and secure the device 46

Completing the implant procedure 47

Marquis DR 7274 Reference Manual

How to complete programming the device 47

5 Conducting a patient follow-up session 49

Patient follow-up guidelines 50

Verifying the status of the implanted system 50

Verifying accurate detection and appropriate therapy 51

Considerations 51

Verifying effective bradycardia pacing 52

Considerations 53

Part III Configuring the ICD for the patient

6 Detecting tachyarrhythmias 57

Detection overview 58

Suspending tachyarrhythmia detection 60

Setting up sensing 61

Parameters 61 Considerations 61 How to program sensitivity 63 Details about sensing 64

Detecting VF episodes 66

Parameters 66 Considerations 67 Restrictions 68 How to program VF detection 68 Details about VF detection 68

Detecting VT episodes 70

Parameters 70 Considerations 70 Restrictions 71 How to program VT detection 72 Details about VT detection 72

Detecting FVT episodes 76

Parameters 76 Considerations 76 Restrictions 77 How to program FVT detection 78 Details about FVT detection 78

Detecting tachyarrhythmia episodes with Combined Count 81

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Marquis DR 7274 Reference Manual

Table of contents

Details about Combined Count detection 81

Monitoring episodes for termination or redetection 84

Parameters 84 Considerations 84 How to program redetection parameters 85 Details about episode termination and redetection 85

Enhancing detection with PR Logic criteria 88

Parameters 88 Considerations 89 Restrictions 90 How to program the PR Logic detection criteria 91 Details about PR Logic pattern and rate analysis 91 Details about the PR Logic detection criteria 95

Enhancing VT detection with the Stability criterion 97

Parameters 97 Considerations 97 How to program Stability 98 Details about Stability 98

Detecting double tachycardias 100

Details about double tachycardia detection 100

Detecting prolonged tachyarrhythmias with High Rate Timeout 101

Parameters 101 Considerations 101 How to program High Rate Timeout 102 Details about High Rate Timeout 102

Key terms 103

7 Treating tachyarrhythmia episodes 109

Treating VF with defibrillation 110

Parameters 110 Considerations 111 Restrictions 112 How to program VF therapies 112 Details about VF therapy 112

Treating VT and FVT with antitachycardia pacing 120

Parameters for all ATP therapies 120 Parameters for Burst therapy 121 Parameters for Ramp therapy 121 Parameters for Ramp+ therapy 122

Marquis DR 7274 Reference Manual

Table of contents

Considerations 122 Restrictions 123 How to program ATP therapies 123 Details about ATP therapies 124

Treating VT and FVT with cardioversion 130

Parameters 130 Considerations 131 Restrictions 132 How to program cardioversion therapies 132 Details about cardioversion therapy 133

Optimizing therapy with Smart Mode and Progressive Episode Therapies 139

Parameters 139 Considerations 139 Restrictions 140 How to program Smart Mode 140 Details about Smart Mode 141 How to program Progressive Episode Therapies 142 Details about Progressive Episode Therapies 142

Key terms 143

vii

8 Treating bradycardia 147

Providing basic pacing therapy 148

Parameters 148 Considerations 149 Restrictions 151 How to program bradycardia pacing parameters 151 Details about basic bradycardia pacing 152

Dual-chamber pacing 154

Parameters 154 Considerations 156 Details about dual-chamber pacing 156 Programming considerations for atrial rates 161

Single chamber pacing 164

Parameters 164 Considerations 164 Details about single chamber pacing 165

Enhancing pacing for optimal cardiac output 167

Parameters 167

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viii

Table of contents

Considerations 169 Restrictions 170 How to program Rate Response 170 Details about Rate Responsive Pacing 171 How to program Rate Adaptive AV 175 Details about Rate Adaptive AV 175 How to program Single Chamber Hysteresis 176 Details about Single Chamber Hysteresis 177 How to program Ventricular Rate Stabilization 178 Details about Ventricular Rate Stabilization 178

Adjusting the pacing rate with Mode Switch 180

Parameters 180 Considerations 180 Restrictions 181 How to program Mode Switch 182 Details about Mode Switch 182

Preventing competitive atrial pacing 184

Parameters 184 Considerations 184 How to program Non-Competitive Atrial Pacing 185 Details about Non-Competitive Atrial Pacing 185

Detecting and preventing pacemaker-mediated tachycardia 189

Parameters 189 How to Program PVC Response and PMT Intervention 190 Details about PVC Response 190 Details about PMT Intervention 191

Providing Ventricular Safety Pacing 193

Parameters 193 Restrictions 193 How to program Ventricular Safety Pacing 194 Details about Ventricular Safety Pacing 194

Providing pacing after high voltage therapies 196

Parameters 196 Considerations 196 How to program pacing after high voltage therapies 197 Details about Post Shock Pacing parameters 197

Key terms 198

Marquis DR 7274 Reference Manual

9 Optimizing charge time and device longevity 203

Optimizing charge time 204

Parameters 204 Considerations 204 How to evaluate charging performance 205 Details about managing charge time 205

Optimizing device longevity 207

Considerations 207

Key terms 208

Part IV Evaluating and managing patient treatment

10 Using the programmer 211

Connecting the programmer hardware 212

Using an external printer 213

To view a list of supported printers 214 Materials you will need 214 To connect the printer to your programmer 216

Using the programming head 218

During an episode in progress 218 During marker transmissions 218 How capacitor charging affects the light array 219 Alternative program and interrogate buttons 219

Display screen features 219

Programmer status bar display 220 Live Rhythm Monitor window 221 Task area 222 Command bar 224 Tool palette 224 Buttons 226

Setting programmer preferences 226

How to set the programmer time and date 227 How to set audio preferences 227 How to select a different language 228 How to check the software version number 229 How to set printing preferences 229 How to set reports preferences 230

Starting and ending patient sessions 230

Table of contents

Marquis DR 7274 Reference Manual

Table of contents

How to start a patient session 231 How to end a patient session 232 Automatic interrogation 232

Viewing live waveforms 233

Parameters 233 How to use the Adjust window 234 How to use the waveform adjustment button bar 235 Details about the live rhythm monitor 235

Recording live waveforms 240

Printing a report while recording live ECG 241

Saving and retrieving device data 242

Considerations 242 How to save ICD data to a disk 243 How to read ICD data from a disk 243 Saving data to a disk 245 Data file names 245 Reading device data from diskette 245

Printing reports 246

How to print a report 247 Print Queue 247

Key terms 248

11 Using system evaluation tools 249

A summary of system evaluation tools 250

Automatic daily measurements 250

Taking a quick look at device activity 251

How to use Quick Look 251 Quick Look observations 252

Using the Patient Alert feature 253

Parameters 253 Considerations 255 How to program the Patient Alert feature 258 Instructing the patient 258 Viewing the Patient Alert events 259 How to view the Patient Alert events 260

Streamlining follow-ups with Checklist 261

How to select and use a checklist 262 How to create, edit, and delete a checklist 263

Marquis DR 7274 Reference Manual

Table of contents

Key terms 264

12 Setting up and viewing collected data 265

A summary of data collection 266

Setting up data collection 267

Parameters 267 Considerations 268 How to set up data collection 269 Details about data collection parameters 269 How to clear collected data 273

Collecting lead performance data 274

Daily lead impedance and EGM amplitude measurements 274 Sensing integrity counter 275

Viewing the episode and therapy efficacy counters 275

How to view and print counter data 276 Details about the episode and therapy efficacy counters 277 Therapy counters 279

Viewing episode data 280

How to view episode data 281 Details about episode data 282 How to view an Interval Plot 284 How to view an EGM Strip 285 How to display the episode text information 287

Viewing Flashback Memory 288

How to view the Flashback Memory 289

Viewing battery and lead status data 290

How to view battery and lead status data 292

Viewing lead performance trends 292

How to view lead performance trend graphs 293

Using Cardiac Compass to view long term clinical trends 294

How to print a Cardiac Compass report 296 Details on Cardiac Compass trend data 296

Viewing and entering patient information 301

How to view and enter new patient information 303 Displaying and printing patient information 303

Automatic device status monitoring 304

Device status indicator warnings 304 How to respond to an electrical reset 305

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xii

Table of contents

13 Testing the system 311

14 Conducting Electrophysiologic Studies 323

Key terms 306

Testing overview 312

Evaluating the underlying rhythm 312

Considerations 312 How to Perform an Underlying Rhythm test 313

Measuring pacing thresholds 313

Parameters 314 Considerations 315 How to perform a Pacing Threshold Test 315

Measuring lead impedance 316

Considerations 316 How to perform a Lead Impedance test 316 Details about the Lead Impedance test 317

Measuring EGM Amplitude 318

Parameters 318 Considerations 318 Restrictions 319 How to perform an EGM Amplitude test 320

Testing the device capacitors 320

Considerations 320 How to perform a Charge/Dump test 321

Key terms 322

EP Study overview 324

Inducing VF with T-Shock 326

Parameters 326 Considerations 327 Restrictions 327 How to deliver a T-Shock induction 328 Details about T-Shock

induction 328

Inducing VF with 50 Hz Burst 329

Parameters 329 Considerations 330 How to deliver a 50 Hz Burst induction 331 Details about 50 Hz Burst induction 332

Inducing an arrhythmia with Manual Burst 332

Marquis DR 7274 Reference Manual

Parameters 332 Considerations 333 How to deliver a Manual Burst induction 334 Details about Manual Burst induction 334

Inducing an arrhythmia with PES 335

Parameters 335 Considerations 336 How to deliver a PES induction 337 Details about PES induction 337

Delivering a manual therapy 338

Parameters for manual defibrillation and cardioversion 338 Parameters for manual ATP therapies 338 Considerations 340 How to deliver a manual therapy 340 Details about manual therapies 340

Key terms 341

15 Solving system problems 343

Overview 344

Solving sensing problems 345

Solving tachyarrhythmia detection problems 347

Solving tachyarrhythmia therapy problems 348

Solving bradycardia pacing problems 349

Responding to device status indicators 351

Key terms 352

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xiii

Part V Appendices

A Warnings and precautions 357

General warnings 358

Storage and handling 358

Resterilization 359

Device implantation and ICD programming 359

Lead evaluation and lead connection 361

Follow-up testing 362

Explant and disposal 363

Medical therapy hazards 363

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xiv

Table of contents

Home and occupational environments 365

BDevice Parameters367

Emergency settings 368

Detection parameters 369

Therapy parameters 371

Bradycardia pacing parameters 373

System maintenance parameters 376

Data collection parameters 377

System test and EP study parameters 378

Fixed parameters 381

Patient information parameters 383

Programmer symbols 384

Parameter Interactions Window 385

Parameter interlocks 386

Index 387

Marquis DR 7274 Reference Manual

Introduction

Using this manual

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

■

Refer to the product literature packaged with the ICD for information about prescribing the ICD.

■

Thoroughly read this manual and the technical manuals for the leads used with the device.

■

Discuss the procedure and the ICD system with the patient and any other interested parties, and provide them with any patient information packaged with the ICD.

Contacting technical support

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.

Introduction

In addition, Medtronic maintains a professional staff of consultants to provide technical consultation to product users. For medical consultation, Medtronic can often refer product users to outside medical consultants with appropriate expertise.

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.

Customer education

Medtronic invites physicians to attend an education seminar on the complete ICD system. The course includes indications for use, an overview of ICD system functions, implant procedures, and patient management.

Marquis DR 7274 Reference Manual

xvi

Introduction

References

Notice

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

See these additional references for more background information:

■

Singer I, Ed. Implantable Cardioverter-Defibrillator. Armonk, NY: Futura Publishing Co. 1994.

■

Singer I, Barold SS, Camm AJ, Eds. Nonpharmacological Therapy of Arrhythmias for the 21st Century: The State of the Art. Armonk, NY: Futura Publishing Co. 1998.

■

Estes M, Manolis AS, Wang P, Eds. Implantable Cardioverter-Defibrillators. New York, NY: Marcel Dekker, Inc.

1994.

■

Kroll MW, Lehmann MH, Eds. Implantable Cardioverter-Defibrillator Therapy: The Engineering-Clinical Interface. Norwell, MA: Kluwer Academic Publishers 1996.

This 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, INCIDENTIAL OR CONSEQUENTIAL DAMAGES TO ANY THIRD PARTY WHICH RESULTS FROM THE USE OF THE INFORMATION PROVIDED IN THE SOFTWARE.

Marquis DR 7274 Reference Manual

Abbreviations and acronyms

Atrial

A-

Atrial Fibrillation

Abbreviations and acronyms

xvii

AFib/AFlutter

Atrial Refractory Period

ARP

Antitachycardia Pacing

ATP

Atrial Vulnerable Period

AVP

Beginning of Life

BOL

beats per minute

bpm

Combined (VT and VF) Number of Intervals to Detect

CNID

Cardioversion

DF/Defib

Electrocardiogram

ECG

Electrogram

EGM

End of Life

EOL

Elective Replacement Indicator

ERI

Fibrillation Detection Interval

FDI

Fast Ventricular Tachycardia Detection Interval

FTI

Fast Ventricular Tachycardia

FVT

Atrial Fibrillation and/or Atrial Flutter

Defibrillation

Implantable Cardioverter Defibrillator

ICD

joules

-1

reciprocal minutes; for example, pacing pulses per minute

min

milliseconds

millivolts

NCAP

NID

NST

Non-Competitive Atrial Pacing

Number of Intervals to Detect

Non-sustained Tachycardia

Marquis DR 7274 Reference Manual

xviii

Abbreviations and acronyms

Premature Atrial Contraction

PAC

Paced A-V Delay

PAV

Programmed Electrical Stimulation

PES

Pacemaker-Mediated Tachycardia

PMT

an atrial interval

P-P

paces or pulses per minute

ppm

an interval between a P-wave and the subsequent R-wave

P-R

Post Ventricular Atrial Blanking period

PVAB

PVARP

PVC

RAAV

RNID

R-P

R-R

SAV

ST/Sinus Tach

SVT

TDI

V-

VF NID

VRS

VSP

Post Ventricular Atrial Refractory Period

Premature Ventricular Contraction

Rate Adaptive A-V delay

Number of Intervals to Redetect

an interval between an R-wave and the subsequent P-wave

a ventricular interval

Sensed A-V Delay

Sinus Tachycardia

Supraventricular Tachycardia

Tachycardia Detection Interval

volts

Ventricular

Ventricular Fibrillation

VF Number of Intervals to Detect

Ventricular Rate Stabilization

Ventricular Safety Pacing

Ventricular Tachycardia

VT NID

Marquis DR 7274 Reference Manual

VT Number of Intervals to Detect

Quick overview

Part I

Marquis DR 7274 Reference Manual

Physical characteristics 4

Magnet application 5

Longevity projections 6

Replacement indicators 8

Typical charge times 10

High voltage therapy energy 10

Stored data and diagnostics 11

New and enhanced features 14

Quick reference

Marquis DR 7274 Reference Manual

Chapter 1

Physical characteristics

Table 1-1. ICD physical characteristicsa

Volu m e 36 cc

Mass 75 g

H x W x D

Surface area of device can 66 cm

Radiopaque IDc

Materials in contact with human tissue

68.3 mm x 50.8 mm x 13.9 mm

PKC

Titanium / polyurethane / silicone rubber

Battery Lithium silver vanadium oxide

Connectors Two IS-1 connectors for pacing and

sensing, Two DF-1 connectors for high voltage therapy, Active Can electrode (programmable)

Device Port Connector

Typ e

Software Name

SVC DF-1 HVX

SVC

RV DF-1 HVB

Can n/a HVA, Can

V IS-1 bipolar

A IS-1 bipolar

Can

74lead.eps

Suture holes

74Suture.eps

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

Grommets may protrude slightly beyond the can surface.

Engineering series number follows the radiopaque code.

These materials have been successfully tested for the ability to avoid biological incompatibility. The device does not produce an injurious temperature in the surrounding tissue.

Marquis DR 7274 Reference Manual

Magnet application

Bringing a magnet close to the device triggers changes in device operation as shown in Table 1-2. When the magnet is removed, the device returns to its programmed operations.

Table 1-2. Effects of magnet application on the device

Pacing mode as programmed

Pacing rate and interval as programmed

VF, VT, and FVT detection suspended

Quick reference

Magnet application

Patient Alert audible tones (20 seconds or less)

with programmable alert(s) enabled:

■

continuous tone (Test)

■

on/off intermittent tone (seek follow-up)

■

high/low dual tone (urgent follow-up)

with programmable alerts disabled:

■

no tone

■

high/low dual tone (urgent follow-up)

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

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

The Test tone does not sound if “VF Detection/Therapy Off” is the only alert enabled.

Marquis DR 7274 Reference Manual

Chapter 1

Longevity projections

Longevity estimates are based on accelerated battery discharge data and device modeling at 60 ppm (min

■

2.5 V pacing pulse amplitude, 0.4 ms pacing pulse width, and

-1

) pacing rate, with:

30 J delivered therapy energy (see Table 1-3)

■

3 V pacing pulse amplitude, 0.4 ms pacing pulse width, and 30 J delivered therapy energy (see Table 1-4)

This model assumes default automatic capacitor formation setting. As a guideline, each full energy charge decreases device longevity by approximately 24 days.

Device longevity is affected by how certain features are programmed, such as EGM pre-storage. For more information, see “Optimizing device longevity” on page 207.

Considerations for using EGM pre-storage

When the EGM pre-storage feature is programmed off, the device starts to store EGM following the third tachyarrhythmia event and also provides up to 20 seconds of information before the onset of the tachyarrhythmia, including:

■

AA and VV intervals

■

Marker Channel

■

interval plot Flashback

When the EGM pre-storage feature is programmed on, the device also collects up to 20 seconds 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 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 off once you have successfully captured the information of interest.

Marquis DR 7274 Reference Manual

Quick reference

Longevity projections

Table 1-3. Projected longevity in years with 2.5V pacing amplitude and

0.4 ms pulse width

Maximum

energy Percent pacing

charging

frequency

EGM

pre-storage

0% Semi-Annual Off

Quarterly Off

15% Semi-Annual Off

Quarterly Off

50% Semi-Annual Off

Quarterly Off

100% Semi-Annual Off

Quarterly Off

Maximum energy charging frequency may include full energy therapy shocks or capacitor formations.

The data provided for programming EGM pre-storage on is based on a 6 month period (two 3-month follow-up intervals) over the life of the device. Additional use of EGM pre-storage reduces longevity by approximately 25% or 3 months per year.

500 ohm pacing impedance

DDD VVI DDD VVI

8.6 8.6 8.6 8.6

8.5 8.5 8.5 8.5

7.5 7.5 7.5 7.5

7.3 7.3 7.3 7.3

8.3 8.5 8.5 8.6

8.1 8.4 8.3 8.5

7.2 7.4 7.3 7.5

7.0 7.3 7.1 7.3

7.5 8.2 8.0 8.5

7.4 8.0 7.9 8.2

6.6 7.1 7.0 7.3

6.5 7.0 6.8 7.1

6.7 7.7 7.5 8.1

6.5 7.5 7.3 8.0

6.0 6.8 6.6 7.1

5.8 6.5 6.4 6.9

900 ohm pacing impedance

Marquis DR 7274 Reference Manual

Chapter 1

Replacement indicators

Table 1-4. Projected longevity in years with 3V pacing amplitude and

0.4 ms pulse width

500 ohm pacing impedance

DDD VVI DDD VVI

Percent pacing

Maximum energy charging frequency

EGM

pre-storage

0% Semi-Annual Off 8.6 8.6 8.6 8.6

On 8.5 8.5 8.5 8.5

Quarterly Off 7.5 7.5 7.5 7.5

On 7.3 7.3 7.3 7.3

15% Semi-Annual Off 8.1 8.5 8.4 8.6

On 8.0 8.3 8.2 8.4

Quarterly Off 7.1 7.3 7.3 7.5

On 6.9 7.2 7.1 7.3

50% Semi-Annual Off 7.2 8.0 7.8 8.3

On 7.0 7.8 7.6 8.1

Quarterly Off 6.4 7.0 6.8 7.2

On 6.2 6.8 6.7 7.0

100% Semi-Annual Off 6.2 7.3 7.1 8.0

On 6.0 7.1 7.0 7.7

Quarterly Off 5.5 6.5 6.3 6.9

On 5.4 6.3 6.1 6.8

Maximum energy charging frequency may include full energy therapy shocks or capacitor formations.

The data provided for programming ECG pre-storage on is based on a 6 month period (two 3-month follow-up intervals) over the life of the device. Additional use of EGM pre-storage reduces longevity by approximately 25% or 3 months per year.

900 ohm pacing impedance

Replacement indicators

Battery voltage and messages about replacement status appear on the programmer display and on printed reports. Table 1-5 lists the Elective Replacement Indicator (ERI) and the End of Life (EOL) conditions.

Marquis DR 7274 Reference Manual

Quick reference

Replacement indicators

Table 1-5. Replacement indicators

Elective Replacement (ERI) ≤ 2.62 V

End of Life (EOL) 3 months after ERI

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

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 which 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.

Post-ERI conditions – EOL device status is defined as three months following an ERI indication assuming the following post-ERI conditions: 100% DDD pacing at 60 ppm (min

-1

), 3 V,

0.4 ms; 500 Ω pacing load; and six 30 J charges. EOL may be indicated before the end of three months if the device exceeds these conditions.

Marquis DR 7274 Reference Manual

Chapter 1

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 1-6).

Ta bl e 1 -6 . Ty p ic ala full energy charge times

At Beginning of Life (BOL) 5.9 seconds

At Elective Replacement (ERI) 7.5 seconds

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

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 1-7 compares the programmed energy levels delivered by the device to the energy levels stored in the capacitors before delivery.

Marquis DR 7274 Reference Manual

Quick reference

Stored data and diagnostics

Table 1-7. Comparing delivereda (programmed) and storedb energy levels

Energy (J)

Delivered

Programmed Stored

Charge

Time

(sec)

Delivered a/ Programmed Stored

30 35 5.9 8 9.4 1.6

28 33 5.6 7 8.3 1.4

26 31 5.2 6 7.1 1.2

24 28 4.7 5 5.9 1.0

22 26 4.4 4 4.7 0.8

20 24 4.0 3 3.6 0.6

18 21 3.5 2 2.4 0.4

16 19 3.2 1.8 2.2 0.4

15 18 3.0 1.6 2.0 0.3

14 16 2.7 1.4 1.7 0.3

13 15 2.5 1.2 1.5 0.3

12 14 2.4 1.0 1.2 0.2

11 13 2.2 0.8 1.0 0.2

10 12 2.0 0.6 0.8 0.1

9 11 1.9 0.4 0.5 0.1

Energy delivered at connector block into a 75 ohm 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.

Energy (J)

Charge Timec (sec)

Stored data and diagnostics

Table 1-8. Stored data and diagnostics

Episode data

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

EGM capacity for tachy episodes

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

14 minutes of dual-channel EGM, or 23.5 minutes of single-channel EGM

device does not usually store detailed episode records for NST episodes)

Marquis DR 7274 Reference Manual

Chapter 1

Stored data and diagnostics

Table 1-8. Stored data and diagnostics (continued)

EGM capacity for SVT/NST episodes

Brady episodes 53 mode switch episodes

EGM sources 9 options: atrial / ventricular / far-field

EGM options Store before onset; Store during charging

2 minutes of dual-channel EGM, or 3.6 minutes of single-channel EGM

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

before latest VF, before latest VT, and before interrogation

Counter data

Detection counters Lifetime total, since cleared, and since last

session

Episode counters Episodes:

■

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

Therapy efficacy counters

Counts for each VF, FVT, VT Therapy:

■

Delivered

■

Successful

■

Unsuccessful

■

Intervention (manually aborted)

Total number of aborted shocks

Other stored data

Patient Alert events Up to 10 log entries: text and date for the first

Battery and lead measurements

Marquis DR 7274 Reference Manual

time an alert is triggered between interrogations

Battery voltage, last capacitor formation, last charge, lead impedance, EGM amplitude measurements, last high voltage therapy, and sensing integrity counter

Stored data and diagnostics

Table 1-8. Stored data and diagnostics (continued)

Lead performance trends

Cardiac Compass trends

14 days of daily measurements plus 80 weeks of weekly minimum and maximum measurements:

■

Lead impedance: atrial pacing, ventricular pacing, defibrillation pathway, and SVC lead (if used)

■

EGM amplitude: atrial (P-waves), ventricular (R-waves)

14 months of measurement trends:

■

VT and VF episodes per day

■

High voltage therapies delivered per day

■

Ventricular rate during VT or VF

■

Episodes of non-sustained tachycardia per day

■

Heart rate variability

■

Total daily time in AF or AT

■

Ventricular rate during AF or AT

■

Percent pacing per day

■

Patient activity

■

Average day and night ventricular heart rate

Quick reference

Marquis DR 7274 Reference Manual

Chapter 1

New and enhanced features

The following features are new or changed from the 7275 GEM III DR ICD.

Patient management

RapidRead telemetry – Communication between the device and

programmer is approximately 20 times faster than telemetry in previous Medtronic ICD devices. The magnitude of improvement depends on the amount and type of data that is interrogated. RapidRead telemetry is more reliable and has an increased range that makes placing the programming head easier.

Cardiac Compass trends report – This report displays up to 14 months of trend data related to tachyarrhythmia episodes, heart rate, and patient activity. See “Using Cardiac Compass to view long term clinical trends” on page 294.

Patient Alert – The alert duration when a magnet is applied to the device is now 20 seconds. The device also provides several new alerts:

■

SVC (HVX) lead impedance out of range

■

Active Can off without SVC

■

DOO/VOO mode programmed

■

VF Detection programmed off, or fewer than four VF therapies enabled for at least six hours

■

charge circuit timeout occurred

■

excessive charge time ERI

For more information, see “Using the Patient Alert feature” on page 253.

EGM amplitude trends – The device automatically measures R-wave and P-wave EGM amplitudes every day. These daily measurements are included in the data displayed on the Lead Performance Trends screen. See “Setting up data collection” on page 267.

Marquis DR 7274 Reference Manual

Quick reference

New and enhanced features

EGM amplitude test – You can use the EGM Amplitude test to measure R-wave and P-wave EGM amplitudes. The results are reported on the EGM Amplitude Test screen. See “Measuring EGM Amplitude” on page 318.

Lead impedance measurement for SVC (HVX) – Along with other lead impedance measurements, the device provides an independent SVC (HVX) measurement to check the integrity of the supplementary high voltage electrode. See “Measuring lead impedance” on page 316.

Leadless ECG signal – If a supplementary high voltage electrode is placed in the SVC, the device provides the Leadless ECG signal through either the Can to SVC (HVX) or RV (HVB) to SVC (HVX) EGM source. See “Setting up data collection” on page 267.

Expanded pre-onset EGM storage – The device can now store up to 20 seconds of EGM before a tachycardia starts. See “Setting up data collection” on page 267.

Smart Auto Cap Formation – When the Auto Cap Formation Interval is set to Auto, the formation interval automatically adjusts to optimize device longevity and charge times. See “Smart Auto Cap” on page 206.

Ending a patient session – The device audits the programmed parameter settings when you end a patient session and alerts you if any of the settings are atypical. See “Starting and ending patient sessions” on page 230.

Tachyarrhythmia detection

VT Monitoring – VT detection can be set to Monitor, which allows

the device to detect and record VT episodes without delivering therapy or influencing VF detection. See “Monitoring episodes for termination or redetection” on page 84.

Marquis DR 7274 Reference Manual

Chapter 1

New and enhanced features

Tachyarrhythmia therapy

Bradycardia pacing

High Rate Timeout – High Rate Timeout can turn off detection

enhancements (Stability, PR Logic criteria) if a high rate episode is longer than a programmed duration. See “Details about High Rate Timeout” on page 102.

Episode confirmation during and after charging – The device continually monitors the ventricular rhythm during and after charging for cardioversion or defibrillation (when VF confirmation is active) to ensure the arrhythmia is present before delivering the high voltage shock. See “Confirming VF after initial detection” on page 115 and “Confirming VT or FVT after detection” on page 134.

Programmable Active Can – If a supplementary electrode is connected to the SVC (HVX) port, you can deselect the device Can as a high voltage electrode. See “Delivery pathway electrodes” on page 113.

Accelerometer-based rate response – The device uses an accelerometer to provide rate responsive pacing.

Additional bradycardia pacing modes – The device provides asynchronous pacing in the DOO and VOO pacing modes and provides the ODO mode to disable pacing. See Chapter 8, "Treating bradycardia" on page 147.

Enhanced AT-style Mode Switch – Mode Switch episodes are detected using a combination of the median atrial rate and the AF evidence criterion. See “Details about Mode Switch” on page 182.

Marquis DR 7274 Reference Manual

EP studies

Quick reference

New and enhanced features

Defibrillation threshold testing support – The T-Shock and 50 Hz Burst induction screens allow you to monitor time between inductions, program ventricular sensing and VF therapy settings, adjust induction settings, select manual therapies, and retrieve episode records after therapy. See “How to perform defibrillation threshold testing” on page 45.

Backup VVI pacing during atrial inductions – You can choose to have the device deliver backup ventricular pacing during Manual Burst and PES inductions that are delivered to the atrium. See “EP Study overview” on page 324.

Marquis DR 7274 Reference Manual

Chapter 1

New and enhanced features

Marquis DR 7274 Reference Manual

System overview 20

Indications and usage 23

Contraindications 23

Patient screening 23

The Marquis DR system

Marquis DR 7274 Reference Manual

Chapter 2

System overview

The 7274 Marquis DR Dual Chamber Implantable Cardioverter Defibrillator (ICD) system is an implantable medical device system that automatically detects and treats episodes of ventricular fibrillation, ventricular tachycardia, fast ventricular tachycardia, and bradyarrhythmia. The ICD system includes three major components:

■

ICD

The ICD senses the electrical activity of the patient’s heart via the sensing electrodes of the implanted atrial and ventricular leads. It then analyzes the heart rhythm based on selectable sensing and detection parameters. If the ICD detects a tachyarrhythmia, it delivers defibrillation, cardioversion, or antitachycardia pacing therapy to the patient’s heart. If the ICD identifies a bradyarrhythmia, it delivers bradycardia pacing therapy to the patient’s heart.

■

Leads

The ICD can be used with transvenous or epicardial defibrillation leads. The lead system should consist of bipolar or paired unipolar

pacing/sensing leads in each chamber of the heart and one or two high voltage cardioversion/ defibrillation electrodes. You can program the Active Can device case as a high voltage electrode. The pacing and sensing electrodes in each chamber sense cardiac activity and deliver pacing stimuli.

■

Programmer and software

The Medtronic 9790C

programmer and 9966 application

software allow you to

■

configure the detection, therapy, and bradycardia features for your patient

■

perform electrophysiological studies and system tests

■

monitor, display, or print patient cardiac activity information

With an appropriate unipolar to bipolar adapter kit.

With the model 9767 or 9767L programming head

Marquis DR 7274 Reference Manual

For information about:

■

indications, contraindications, lead compatibility, warnings and precautions, and patient selection, see the Marquis DR 7274 Implant Manual, which accompanies each device.

■

basic programmer and software desktop functions that are not included in Chapter 10, "Using the programmer" on page 211, see the manual accompanying the programmer.

■

installing the 9767 or 9767L programming head, see the manual accompanying the programming head.

■

implanting leads, refer to the manuals accompanying the leads.

Detecting and treating tachyarrhythmias

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

■

Upon detection of VF, the ICD delivers a biphasic defibrillation shock of up to 30 joules. If the VF episode persists, up to five more individually programmed defibrillation shocks can be delivered.

■

Upon detection of VT, the ICD delivers either a Ramp, Ramp+, or Burst antitachycardia pacing therapy or a biphasic cardioversion shock of up to 30 joules synchronized to a ventricular depolarization. If the VT episode persists, up to five more individually programmed VT therapies can be delivered. You can also program the ICD to monitor the VT episode without delivering therapy.

■

Upon detection of FVT, the ICD delivers either a Ramp, Ramp+, or Burst antitachycardia pacing therapy or a biphasic cardioversion shock of up to 30 joules synchronized to a ventricular depolarization. If the FVT episode persists, up to five more individually programmed FVT therapies can be delivered.

The Marquis DR system

System overview

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

You can also program the ICD 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.

Marquis DR 7274 Reference Manual

Chapter 2

System overview

Treating bradycardia

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

Monitoring for real-time and stored data

The ICD and programmer provide real-time information on

detection and therapy parameters and status during a patient session. The ICD also provides accumulated data on device operation, including 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 arrhythmia episodes, therapies delivered, physical activity, heart rate, and bradycardia pacing activities.

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

Conducting electrophysiologic tests

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

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.

Marquis DR 7274 Reference Manual

Indications and usage

The implantable cardioverter defibrillator is intended to provide ventricular antitachycardia pacing and ventricular defibrillation for automated treatment of life threatening ventricular arrhythmias.

Contraindications

The Marquis DR system is contraindicated for

■

patients whose tachyarrhythmias may have transient or reversible causes, such as acute myocardial infarction, digitalis intoxication, drowning, electrocution, electrolyte imbalance, hypoxia, or sepsis.

■

patients with incessant VT or VF

■

patient who have a unipolar pacemaker

■

patients whose primary disorder is bradyarrhythmias or atrial arrhythmias

The Marquis DR system

Indications and usage

Patient screening

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 and/or medical therapy.

Marquis DR 7274 Reference Manual

Chapter 2

Patient screening

Marquis DR 7274 Reference Manual

Emergency therapy

Delivering emergency therapies 26

How to deliver emergency 30 joule defibrillation 28

How to deliver emergency cardioversion 28

How to deliver emergency fixed burst pacing 29

How to deliver emergency VVI pacing 30

Marquis DR 7274 Reference Manual

Chapter 3

Delivering emergency therapies

The device provides the following emergency therapies:

■

defibrillation

■

cardioversion

■

fixed burst pacing

■

emergency VVI pacing

The default emergency therapy is 30 joule defibrillation. When you select [Emergency] and [DELIVER], the device charges and delivers a biphasic 30 joule shock along the AX>B pathway

The programmer resets the emergency defibrillation energy to 30 joules 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].

Effect on system operation

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.

Aborting an emergency therapy

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

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

Marquis DR 7274 Reference Manual

On-screen and display panel buttons

The on-screen [Emergency] button and the red mechanical Emergency button by the programmer display panel function the same at all times.

Red Emergency

Button

The on-screen [DELIVER] button and the yellow-on-blue mechanical Deliver button by the programmer display panel function the same during emergency operations only. The mechanical Deliver button operates only during emergency operations.

Emergency therapy

Delivering emergency therapies

Functions the same as on-screen [Emergency] button.

Yellow-on-blue

Deliver Button

Temporary parameter values

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

Functions the same as on-screen [DELIVER], but only during Emergency functions.

These

Delivery of Emergency VVI Pacing changes the programmed bradycardia pacing values to the emergency values (see page 30).

Marquis DR 7274 Reference Manual

Chapter 3

Delivering emergency therapies

How to deliver emergency 30 joule defibrillation

How to deliver emergency cardioversion

1. Position the programming head over the device.

2. Select [Emergency].

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

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

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

1. Position the programming head over the device.

2. Select [Emergency].

3. Select [Cardioversion].

4. Accept the cardioversion energy shown on the screen, or select Energy and select a new value from the window.

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

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

Marquis DR 7274 Reference Manual

How to deliver emergency fixed burst pacing

Emergency therapy

Delivering emergency therapies

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 Interval for 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].

Marquis DR 7274 Reference Manual

Chapter 3

Delivering emergency therapies

How to deliver 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 (70 min-1)

■

V. Amplitude: 6 V

■

V. Width: 1.6 ms

■

V. Pace Blanking: 240 ms

■

Hysteresis: Off

■

Ventricular Rate Stabilization: Off

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

Marquis DR 7274 Reference Manual

Part II

Device implant and patient follow-up procedures

Marquis DR 7274 Reference Manual

Implanting the ICD

Overview 34

Preparing for an implant 34

Replacing an ICD 36

Positioning the leads 37

Testing sensing and pacing thresholds 39

Connecting the leads to the ICD 40

Testing defibrillation operation and effectiveness 42

Positioning and securing the ICD 46

Completing the implant procedure 47

Marquis DR 7274 Reference Manual

Chapter 4

Overview

Preparing for an implant

The tasks for implanting an ICD include

1. Preparing for an implant

2. Replacing an ICD

3. Positioning the leads

4. Testing sensing and pacing thresholds

5. Connecting the leads to the ICD

6. Testing defibrillation operation and effectiveness

7. Positioning and securing the ICD

8. Completing the implant procedure

These tasks are described in the sections that follow.

Warning: Keep a back-up external defibrillator available during the implant for transthoracic rescue when arrhythmias are induced.

Equipment for an implant

■

Model 9790c programmer and Model 9767 or 9767L programming head

■

9966 software application

■

8090 Analyzer lead analysis device or equivalent pacing system analyzer

■

external defibrillator

■

5358 Defibrillator Implant Support Device and software application (optional)

Marquis DR 7274 Reference Manual

Sterile supplies

■

Marquis DR ICD and lead system components

■

Programming head sleeve or programming head

■

Analyzer cables

■

Lead introducers appropriate for the lead system

■

Extra stylets of appropriate length and shape

How to prepare for implanting

Set up the implant support instrument

When using an implant support instrument such as the 5358 Defibrillator Implant Support Device:

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.

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 Marquis DR Model 9966 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.

Implanting the ICD

Preparing for an implant

Marquis DR 7274 Reference Manual

Chapter 4

Replacing an ICD

Preprogram the device

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

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 could be reduced.

2. Interrogate the ICD, and print a full summary report.

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

If the device has been exposed to lower temperatures or has delivered a recent high voltage charge, the battery voltage will be temporarily lower.

4. Set up data collection parameters and the ICD internal clock (see page 269).

5. Perform a manual capacitor formation (see page 320).

6. Program the therapy and pacing parameters to values appropriate for the patient (see page 151). Ensure that all tachyarrhythmia detection is programmed Off (see page 58).

Use the Quick Look screen to verify the voltage, see page 251.

Replacing an ICD

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

When implanting the ICD 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.

■

Ensure proper fit of the lead connectors in the ICD connector block.

Marquis DR 7274 Reference Manual

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.

How to explant and replace an ICD

1. Program all tachyarrhythmia detection Off.

2. Dissect the leads and the ICD 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 ICD 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 ICD or an implant support instrument.

7. Evaluate the defibrillation efficacy of the replacement system.

Implanting the ICD

Positioning the leads

Implant endocardial leads according to the supplied instructions, unless suitable chronic leads are already in place. Do not use any lead with this device without first verifying connector compatibility (refer to the Marquis DR 7274 Implant Manual). Transvenous or epicardial leads may be used. A bipolar atrial lead with closely spaced pacing and sensing electrodes is recommended.

Using transvenous leads

Use standard transvenous implant techniques to position the ventricular lead tip in the right ventricular apex and the atrial pacing lead tip high on the right atrial appendage.

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

Marquis DR 7274 Reference Manual

Chapter 4

Positioning the leads

Using epicardial leads

■

SVC (HVX) lead: Place the lead tip high in the innominate vein, approximately 5 cm proximal to the right atrium (RA) and SVC junction.

■

SQ patch: Place the patch along the left mid-axillary, centered over the fourth-to-fifth intercostal space.

■

CS lead: Advance the lead tip to just under the left atrial appendage, if possible.

If using a subclavian approach, position the lead laterally to avoid pinching the lead body between the clavicle and the first rib.

Warning: Pinching the lead can damage the lead conductor or insulation, which may cause unwanted high voltage therapies or result in the loss of sensing or pacing therapy.

A variety of surgical approaches can be used to implant epicardial leads, including a limited left thoracotomy or median sternotomy. A typical placement may use an anterior right ventricular patch as the RV (HVB) and a posterolateral left ventricular patch as SVC (HVX).

Follow the general guidelines below for positioning epicardial leads:

■

If unipolar epicardial pacing leads are used, position the electrodes about 1 to 2 cm apart to reduce electromagnetic interference, and route the leads together with several loose twists.

■

Suture the smooth face of each patch lead against the epicardium or pericardium in locations that produce optimal defibrillation.

■

Place the patches so that they encompass the maximum amount of cardiac mass and they have approximately equal amounts of mass between them.

■

Ensure that the patches do not overlap and the electrode portions do not touch.

■

Avoid placing extra-pericardial patches over the phrenic nerve.

Marquis DR 7274 Reference Manual

Testing sensing and pacing thresholds

Surgical incisions

A single-incision submuscular or subcutaneous approach is recommended when the ICD is implanted in the pectoral region. Make the implant pocket about 1.5 times the size of the ICD.

Submuscular implant – An incision extending over the deltoid-pectoral groove typically provides access to the cephalic and subclavian veins as well as the implant pocket. Place the ICD sufficiently medial to the humeral head to avoid interference with shoulder motion.

Subcutaneous implant – A transverse incision typically permits isolation of the cephalic vein. Place the ICD far medially to keep the leads away from the axilla. Make sure that the upper edge of the ICD remains inferior to the incision.

Testing sensing and pacing thresholds

Sensing and pacing tests include the following measurements:

■

EGM amplitude

■

slew rate

■

pacing threshold

■

pacing lead impedance

Implanting the ICD

Medtronic recommends that you use an 8090 Analyzer lead analysis device to perform sensing and pacing measurements. If you use a Pacing System Analyzer (PSA), perform both atrial and ventricular measurements via the ventricular channel of the PSA.

Refer to the technical manual for the Analyzer you use to find details on performing sensing and pacing measurements.

Marquis DR 7274 Reference Manual

Chapter 4

Connecting the leads to the ICD

Parameters

Considerations

Measured sensing and pacing values must meet the following specific requirements at implant.

Table 4-1. Sensing and pacing values at implant

Measurement Acute Transvenous Leads Chronic Leads

R- wave amplitude ≥ 5 mV ≥ 3 mV

P- wave amplitude ≥ 2 mV ≥ 1 mV

Slew rate:

atrial ≥ 0.5 V/s ≥ 0.3 V/s

ventricular ≥ 0.75 V/s ≥ 0.5 V/s

Capture threshold

atrial ≤ 1.5 V ≤ 3.0 V

ventricular ≤ 1.0 V ≤ 3.0 V

At 0.5 ms pulse width

When measuring sensing and pacing values, measure between the tip (cathode) and ring or coil (anode) of each bipolar pacing/sensing lead.

For unipolar epicardial pacing leads, either electrode can be the cathode; use the configuration that yields the lower pacing threshold.

Note: Do not measure the intracardiac EGM telemetered from the ICD to assess sensing.

Connecting the leads to the ICD

For more detailed information about lead/connector compatibility, see the Marquis DR 7274 Implant Manual, or contact Medtronic Technical Services at 1-800-723-4636.

Marquis DR 7274 Reference Manual

Implanting the ICD

Connecting the leads to the ICD

Table 4-2. Lead connections

Device Port

Connector Type

Software Name

SVC DF-1 HVX

SVC

RV DF-1 HVB

Can n/a HVA, Can

V IS-1 bipolar

Can

74lead.eps

A IS-1 bipolar

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

Caution: Use only the torque wrench supplied with the device. It is designed to prevent damage to the device from overtightening a setscrew.

For easier lead insertion, insert the ventricular IS-1 leg before the other legs.

How to connect the lead to the device

74SetScrew.eps

74LeadTIp.eps

1. Insert the torque wrench into the appropriate setscrew.

a. If the port is obstructed, 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 pull on the lead until all setscrews have been tightened.

5. Repeat these steps for each lead.

Marquis DR 7274 Reference Manual

Chapter 4

Testing defibrillation operation and effectiveness

To demonstrate reliable defibrillation effectiveness with the implanted lead system, use the ICD to complete one of the following tests:

■

Terminate two consecutively induced VF episodes using a delivered energy of 20 joules or less.

■

Use the binary search procedure to establish a defibrillation threshold (DFT) of 18 joules or less.

Note: An external defibrillation implant support instrument can also be used to test defibrillation effectiveness. For instructions, see the applicable documentation for the specific support instrument.

High voltage implant values

Measured values must meet the following requirements at implant.

Table 4-3. High voltage therapy values at implant

Measurement Acute or Chronic Leads

V. Defib impedance

SVC (HVX) impedance (if applicable)

Defibrillation threshold

20 - 200 ohms

≤ 20 J (two consecutive) or ≤ 18 J (binary search)

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

Marquis DR 7274 Reference Manual

Binary search protocol

By testing defibrillation efficacy at successively lower energy levels, the binary search protocol provides an accurate threshold measurement. However, it generally requires more inductions and more time. Also, cumulative charging of the ICD capacitor affects the device longevity.

For most reliable defibrillation efficacy testing, allow at least five minutes between VF inductions. The ICD software provides an on-screen timer to record elapsed time since the last induction.

If a two-electrode system fails to meet the implant criterion, consider implanting a third electrode and connecting it to the SVC (HVX) port. You can also evaluate the efficacy of ventricular tachycardia and atrial arrhythmia therapies after successfully completing ventricular defibrillation testing.

Figure 4-1. Binary search protocol

Implanting the ICD

Testing defibrillation operation and effectiveness

Start

First induced episode

Second induced episode

Third induced episode

Defibrillation Threshold

Success Failure

Success Failure FailureSuccess

3 J

Success Failure Success Failure Success Failu re

<=3 J 6 J 9 J 15 J 18 J

The timer appears on the 50 Hz Burst and T-Shock induction screens.

6 J

9 J 15 J

Implant

Criterion Met

12 J

Success

Reprogram polarity, reposition the lead, or try a different lead

Tr y t o me et

2 at 20 J

Failure

18 J

74binary.eps

Marquis DR 7274 Reference Manual

Chapter 4

Testing defibrillation operation and effectiveness

How to prepare for defibrillation threshold testing

1. Place the programming head over the ICD, 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 ICD is sensing properly.

3. Conduct a manual Lead Impedance Test lead connections. Perform this test with the ICD 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 ICD or support instrument to properly detect VF with an adequate safety margin (1.2 mV sensitivity).

See “Measuring lead impedance” on page 316.

to verify the defibrillation

Marquis DR 7274 Reference Manual

Testing defibrillation operation and effectiveness

How to perform defibrillation threshold testing

Implanting the ICD

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 2-6 should be set to the maximum energy.

7. Select [Program].

8. Select [Close].

Marquis DR 7274 Reference Manual

Chapter 4

Positioning and securing the ICD

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. If using the binary search protocol, use the [Adjust Permanent...] button to program the next appropriate energy level (see Figure 4-1).

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

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

Positioning and securing the ICD

Cautions: If no SVC electrode is implanted, the pin plug

provided with the device must be secured in the SVC port.

Program tachyarrhythmia detection Off before closing.

How to position and secure the device

Suture Hole Locations

Marquis DR 7274 Reference Manual

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. This position optimizes the ambulatory monitoring operations.

4. Suture the device securely within the pocket to

74Suture.eps

minimize post-implant rotation and migration of the device. Use a surgical needle to penetrate the suture holes.

Completing the implant procedure

After implanting the device, X-ray the patient to verify the device and leads placement. To complete programming the device, select parameters that are appropriate for the patient.

How to complete programming the device

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

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

3. If external equipment was used to conduct the defibrillation efficacy tests, perform a final VF induction, and allow the implanted system to detect and treat the arrhythmia.

4. Monitor the patient after the implant, and take X-rays as soon as possible to document and assess the location of the leads.

5. Program patient information. See “How to view and enter new patient information” on page 303.

6. Configure the Patient Alert feature. See “Using the Patient Alert feature” on page 253.

7. Set up data collection parameters. See “Setting up data collection” on page 267.

8. Interrogate the device after any spontaneous episodes to evaluate the detection and therapy parameter settings.

9. If the patient has not experienced spontaneous episodes, you 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" on page 323.

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

Implanting the ICD

Completing the implant procedure

Marquis DR 7274 Reference Manual

Chapter 4

Completing the implant procedure

Marquis DR 7274 Reference Manual

Conducting a patient follow-up

Patient follow-up guidelines 50

Verifying the status of the implanted system 50

Verifying accurate detection and appropriate therapy 51

Verifying effective bradycardia pacing 52

session

Marquis DR 7274 Reference Manual

Chapter 5

Patient follow-up guidelines

Schedule regular patient follow-up sessions to monitor the condition of the ICD and leads and to verify that the ICD 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 three 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

■

verify that the device is functioning correctly.

■

review the clinical performance and long term trends.

■

print appropriate reports1 to compare the results to the patient’s history and to retain for future reference.

Note: The Checklist feature provides a standard list of tasks to perform at a complete follow-up visit. You can also customize your own checklists if you wish. See “Streamlining follow-ups with Checklist” on page 261 for more information.

Verifying the status of the implanted system

To verify that the ICD 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 page 8). Remember that battery 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 “Optimizing charge time” on page 204.

– If the programmer displays an Excessive Charge Time ERI,

the ICD should be replaced immediately.

See “Using Cardiac Compass to view long term clinical trends” on page 294 for information on this new report.

Marquis DR 7274 Reference Manual

Conducting a patient follow-up session

Verifying accurate detection and appropriate therapy

■

Review the defibrillation and pacing lead impedance values for inappropriate values or large changes since the last follow-up. See “Measuring lead impedance” on page 316.

■

Perform an EGM Amplitude test in each chamber for comparison to previous EGM Amplitude measurements. See “How to perform an EGM Amplitude test” on page 320.

■

To review longer term trends in sensing and impedance measurements, select the [>>] button from the lead impedance area of the Quick Look screen. The programmer displays a detailed history of automatic sensing and impedance measurements. See “Taking a quick look at device activity” on page 251.

Verifying accurate detection and appropriate therapy

To verify that the ICD 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 [Events].

■

Check stored episode records for appropriate sensing and detection of arrhythmias. See “Viewing episode data” on page 280.

■

Check stored SVT episode records for appropriate identification of SVTs.

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.

Marquis DR 7274 Reference Manual

Chapter 5

Verifying effective bradycardia pacing

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 “Sensing integrity counter” on page 275.

If the ICD is oversensing, consider these programming options:

■

Increase the Pace Blanking value.

■

Increase the sensitivity threshold.

Caution: Do not re-program the ICD to decrease oversensing without assuring that appropriate sensing is maintained. See “Setting up sensing” on page 61.

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 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 “Detecting FVT episodes” on page 76.

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 “Enhancing detection with PR Logic criteria” on page 88, and “Enhancing VT detection with the Stability criterion” on page 97.

Verifying effective bradycardia pacing

To verify that the ICD is sensing and pacing appropriately, review the following information from the 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 for comparison to the patient history. A sharp increase in the paced beats percentage may indicate a need for investigation and analysis.

Marquis DR 7274 Reference Manual

Considerations

Conducting a patient follow-up session

Verifying effective bradycardia pacing

■

Review the recorded Mode Switch episodes for comparison to the patient’s atrial arrhythmia history. A dramatic increase in frequency or duration of atrial episodes may indicate a need for investigation and analysis.

To display more detailed information about the Mode Switch episodes, perform these steps: select Episodes and Counters from the Data icon; select the Mode Switch episodes from the listed episode counters; then select the [Open Data] button.

■

Review the Cardiac Compass report for comparison to patient history (see page 294).

■

Conduct pacing threshold tests (see page 313) to verify that the programmed pacing outputs provide a sufficient safety margin.

Review the following information before verifying bradycardia pacing.

Atrial Pacing – If the conduction history shows 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.

Ventricular Pacing – If the ventricle is predominantly paced and the patient exhibits adequate ventricular response, consider these options:

■

Decrease the Lower Rate.

■

Increase the AV delays.

Conduction History – If the reported percentages in the conduction history do not add up to 100, the percentages may be rounded. Frequent premature contractions or A:V dissociation may also be the cause. Consider any of the following options:

■

Program the pacing mode to DDD or DDDR to promote A-V synchrony. (If appropriate, enable Mode Switch to keep the benefits of DDIR pacing during atrial high rate episodes.)

■

Enable Ventricular Rate Stabilization to smooth the heart rate following premature ventricular beats.

Marquis DR 7274 Reference Manual

Chapter 5

Verifying effective bradycardia pacing

Marquis DR 7274 Reference Manual

Part III

Configuring the ICD for the patient

Marquis DR 7274 Reference Manual

Detecting tachyarrhythmias

Detection overview 58

Setting up sensing 61

Detecting VF episodes 66

Detecting VT episodes 70

Detecting FVT episodes 76

Detecting tachyarrhythmia episodes with Combined Count 81

Monitoring episodes for termination or redetection 84

Enhancing detection with PR Logic criteria 88

Enhancing VT detection with the Stability criterion 97

Detecting double tachycardias 100

Detecting prolonged tachyarrhythmias with High Rate Timeout 101

Key terms 103

Marquis DR 7274 Reference Manual

Chapter 6

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.

Figure 6-1 shows how all of these detection features interact during initial detection. 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 “How to program VF detection” on page 68.

Marquis DR 7274 Reference Manual

Detecting tachyarrhythmias

Figure 6-1. How detection features interact during initial detection

Detection overview

Ye s

No / suspended by High Rate Timeout

Ye s

Update counts and pattern information

Ventricular Event

Is the interval in the

VF, FVT, or VT detection zone?

Ye s

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?

Ye s

Are one or more PR Logic criteria on?

Ye s

Is the median ventricular interval less than the SVT

Limit?

Ye s

Tachy

Episode

Detected

Ye s

Is there a double tachycardia in progress?

Are one or more PR Logic criteria withholding

detection?

Marquis DR 7274 Reference Manual

Ye s

Chapter 6

Detection overview

Suspending tachyarrhythmia detection

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

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 page 81) 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 a High Rate Timeout Therapy operation, VT detection is not suspended (see page 103).

Marquis DR 7274 Reference Manual

Setting up sensing

The device provides bipolar sensing in both the atrium and ventricle via the sensing electrodes of the implanted atrial and ventricular 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 details about sensing on page 64.

Parameters

V. Sensitivity (mV) – Minimum amplitude of

electrical signal that registers as a sensed ventricular event.

Detecting tachyarrhythmias

Setting up sensing

* Medtronic nominal setting

0.15, 0.3*, 0.45, 0.6,

0.9, 1.2

Considerations

A. Sensitivity (mV) – Minimum amplitude of

electrical signal that registers as a sensed atrial event.

0.15, 0.3*, 0.45, 0.6,

0.9, 1.2, 1.5, 2.1

Review the following information before programming sensing parameters.

Dual chamber sensing and bradycardia pacing modes – The device senses in both the atrium and the ventricle at all times, except when the programmed bradycardia pacing mode is DOO or VOO. When the pacing mode is programmed to DOO or VOO mode, there is no sensing in the ventricle. In order to program either DOO or VOO 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.

Marquis DR 7274 Reference Manual

Chapter 6

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.

Marquis DR 7274 Reference Manual

Detecting tachyarrhythmias

Setting up sensing

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.

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.

How to program sensitivity

1. Select Params > Detection.

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

3. Select [PROGRAM].

Marquis DR 7274 Reference Manual

Chapter 6

Setting up sensing

Details about sensing

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. Figure 6-2 shows how sensitivity thresholds are adjusted after different types of events.

Figure 6-2. Auto-adjusting sensitivity thresholds

A S

Sensitivity Threshold

V P

74Autoadjust.eps

Rectified and

Filtered A. EGM

Rectified and

Filtered V. EGM

Marker Channel

1 2

A S

V S

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).

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.

Marquis DR 7274 Reference Manual

Detecting tachyarrhythmias

Setting up sensing

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 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 “Post-Ventricular Atrial Blanking Period” on page 160).

Table 6-1 shows the duration of the fixed blanking periods. For information on programmable pace blanking periods, see page 148.

Table 6-1. Fixed blanking periods

Cross-chamber blanking after atrial or ventricular pacing pulse

30 ms

Atrial blanking after sensed atrial event 100 ms

Ventricular blanking after sensed ventricular event 120 ms

Atrial and ventricular blanking after delivered cardioversion or defibrillation therapy

Marquis DR 7274 Reference Manual

520 ms

Chapter 6

Detecting VF episodes

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 “Synchronizing defibrillation without confirming VF” on page 114 and “Synchronizing cardioversion after charging” on page 135.

Note: Refractory periods do not affect tachyarrhythmia detection.

The device detects VF episodes by examining the cardiac rhythm for short ventricular intervals. If a predetermined number of intervals occurs 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 details about VF detection on page 68.

Parameters

VF Detection Enable – Turns VF

detection on or off.

VF Interval (ms) – 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.

Marquis DR 7274 Reference Manual

* Medtronic nominal setting

On*, Off

240, 250, . . ., 320*, . . .,400

12/16, 18/24*, 24/32, 30/40, 45/60, 60/80, 75/100, 90/120, 105/140, 120/160

6/8, 9/12, 12/16*, 18/24, 21/28, 24/32, 27/36, 30/40

Considerations

Detecting tachyarrhythmias

Detecting VF episodes

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 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.

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

■

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 “Enhancing detection with PR Logic criteria” on page 88.

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 “Detecting double tachycardias” on page 100.

Marquis DR 7274 Reference Manual

Chapter 6

Detecting VF episodes

Restrictions

How to program VF detection

Review the following information before programming VF Detection parameters.

Tachyarrhythmia detection and bradycardia pacing – To e n s u r e reliable ventricular tachyarrhythmia detection, the programmer regulates the values available for bradycardia pacing and tachyarrhythmia detection. See “Parameter interlocks” on page 386.

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.

To program VF detection:

1. Select Params > Detection.

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

3. Select [PROGRAM].

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 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).

Marquis DR 7274 Reference Manual

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 6-3).

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 via the Combined Count detection criterion (see page 81).

Figure 6-3. Device detects VF

ECG

Detecting tachyarrhythmias

Detecting VF episodes

1 2 3

A S

A R

Marker Channel

FSFSFSFSFSFSFSFSFSF

VSVSV

VF Event Count

V S

VSV

FSFSF

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

FSFSF

VF Interval

200 ms

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.

74VFDetection.eps

Marquis DR 7274 Reference Manual

Chapter 6

Detecting VT episodes

Parameters

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.

See details about VT detection on page 72.

* Medtronic nominal setting

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

On, Off*, or Monitor

VT Interval (Rate) (ms) – 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.

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.

Marquis DR 7274 Reference Manual

280, 290, . . ., 400*, . . ., 600

12, 16*, . . ., 52, 76, 100

4, 8, 12*, . . ., 52

Detecting tachyarrhythmias

Detecting VT episodes

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

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 “Detecting tachyarrhythmia episodes with Combined Count” on page 81.

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 “Enhancing VT detection with the Stability criterion” on page 97, and “Enhancing detection with PR Logic criteria” on page 88.

Restrictions

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 page 100).

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.

Marquis DR 7274 Reference Manual

Chapter 6

Detecting VT episodes

How to program VT detection

Details about VT detection

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].

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 number of consecutive VT events reaches the programmed VT Initial NID, the device detects VT (see Figure 6-4).

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 via the Combined Count detection criterion (see page 81).

Marquis DR 7274 Reference Manual

Figure 6-4. Device detects VT

ECG

132

Detecting tachyarrhythmias

Detecting VT episodes

A S

ARARARARARARA

Marker Channel

VT Event Count

V S

VSV

T S

10123456

TSTSTSTSTST

VT Interval

ECG

ARARARARARARARARARARARA

Marker Channel

T D

V S

74VTDetection.eps

VT Event Count

TSTSTSTSTSTSTSTST

78910111213141516

VT Interval

200 ms

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.

Marquis DR 7274 Reference Manual

Chapter 6

Detecting VT episodes

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 6-5). 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.

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

Marquis DR 7274 Reference Manual

Figure 6-5. Device detects and monitors VT

ECG

Detecting tachyarrhythmias

Detecting VT episodes

2 31

A S

ARARA

ARARARARA

A R

Marker Channel

VT Event Count

V S

VSTSTSTST

1234

TSTSTSTDTSTST

13 14 15 16 0 0 0

74VTmonitor.eps

VT Interval

200 ms

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.

Marquis DR 7274 Reference Manual

Chapter 6

Detecting FVT episodes

Parameters

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.

See details about FVT detection on page 78.

* Medtronic nominal setting

FVT Detection Enable – Enables FVT detection via the VF or the VT detection algorithm.

Off*, via VF, or via VT

Considerations

FVT Interval (Rate) (ms) – V-V

intervals between this value and the programmed VF Interval are marked as FVT events.

200, 210, . . ., 600

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.

Marquis DR 7274 Reference Manual

Detecting tachyarrhythmias

Detecting FVT episodes

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 two 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 one 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.

Restrictions

Double tachycardia detection – When any PR Logic detection

criteria is enabled, the device also enables double tachycardia detection (VF, VT, or FVT in the presence of an SVT, see page 100).

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 “Parameter interlocks” on page 386.

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.

Marquis DR 7274 Reference Manual

Chapter 6

Detecting FVT episodes

How to program FVT detection

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.

To program FVT detection:

1. Select Params > Detection.

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

3. Select [PROGRAM].

Details about FVT detection

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

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 eight intervals:

■

If any of the last eight intervals are in the VF zone, it detects the episode as VF.

■

If all of the last eight intervals are outside the VF zone, it detects the episode as FVT (see Figure 6-6).

Marquis DR 7274 Reference Manual

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 eight intervals:

■

If any of the last eight intervals are in the VF or FVT zones, it detects the episode as FVT.

■

If all of the last eight 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 page 81).

Figure 6-6. Device detects FVT via VF

Detecting tachyarrhythmias

Detecting FVT episodes

1 2

ECG

A S

ARARA

A R

ARARARARARARARARA

Marker Channel

VF Event Count

V S

1 12345

TFTFTFT

TFT

TFTFTFTFTFV

13 14 15 16 17 18

VF and FVT Intervals

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.

74FvtDetect.eps

200 ms

Marquis DR 7274 Reference Manual

Chapter 6

Detecting FVT episodes

Figure 6-7. FVT zone merging

Zone merging after detection

To ensure 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 6-7. The merged zone configuration uses the event counting and therapies for the faster arrhythmia and remains in effect until episode termination.

FVT set to “via VF” FVT set to “via VT”

Before detection:

After VF detection:

After FVT detection:

FVT

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

FVT

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

FVT

All zones remain unchanged. VT and FVT zones merge, leaving a

larger FVT zone.

FVT

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

FVT

FVT1.eps

FVT2.eps

FVT3.eps

Marquis DR 7274 Reference Manual

Medtronic 7274 Reference Guide

Specifications and Main Features

Frequently Asked Questions

User Manual

Introduction

Using this manual

Contacting technical support

Customer education

References

Notice

Abbreviations and acronyms

Quick overview

Quick reference

Physical characteristics

Magnet application

Longevity projections

Considerations for using EGM pre-storage

Replacement indicators

Typical charge times

High voltage therapy energy

Stored data and diagnostics

New and enhanced features

Patient management

Tachyarrhythmia detection

Tachyarrhythmia therapy

Bradycardia pacing

EP studies

The Marquis DR system

System overview

Detecting and treating tachyarrhythmias

Treating bradycardia

Monitoring for real-time and stored data

Conducting electrophysiologic tests

Alerting the patient to system events

Indications and usage

Contraindications

Patient screening

Emergency therapy

Delivering emergency therapies

Effect on system operation

Aborting an emergency therapy

Temporary parameter values

How to deliver emergency 30 joule defibrillation

How to deliver emergency cardioversion

How to deliver emergency fixed burst pacing

How to deliver emergency VVI pacing

Device implant and patient follow-up procedures

Implanting the ICD

Overview

Preparing for an implant

Equipment for an implant

Sterile supplies

How to prepare for implanting

Replacing an ICD

How to explant and replace an ICD

Positioning the leads

Using transvenous leads

Using epicardial leads

Testing sensing and pacing thresholds

Surgical incisions

Connecting the leads to the ICD

Parameters

Considerations

How to connect the lead to the device

Testing defibrillation operation and effectiveness

High voltage implant values

Binary search protocol

How to prepare for defibrillation threshold testing

How to perform defibrillation threshold testing

Positioning and securing the ICD

How to position and secure the device

Completing the implant procedure

How to complete programming the device

Patient follow-up guidelines

Verifying the status of the implanted system

Verifying accurate detection and appropriate therapy

Considerations

Verifying effective bradycardia pacing

Considerations

Configuring the ICD for the patient