Cardiac Pacing, Defibrillation and Resynchronization (eBook)

Title page 5
Copyright page 6
Contents 7
Contributors 9
Preface 11
1: Pacing and Defibrillation: Clinically Relevant Basics for Practice 13
Anatomy and physiology of the cardiac conduction system 14
Electrophysiology of myocardial stimulation 14
Pacing basics 16
Stimulation threshold 16
Variations in stimulation threshold 18
Sensing 19
Lead design 21
Bipolar and unipolar pacing and sensing 25
Left ventricular leads 25
Pulse generators 26
Pacemaker nomenclature 28
Defibrillation basics 28
Critical mass 30
Upper limit of vulnerability 30
Progressive depolarization 31
Virtual electrode depolarization 31
Defibrillation theory summary 33
The importance of waveform 33
Biphasic waveforms 34
Phase duration and tilt 35
Polarity and biphasic waveforms 36
Mechanism of improved efficacy with biphasic waveforms 36
Measuring shock dose 36
Measuring the efficacy of defibrillation 37
Threshold and dose–response curve 37
Relationship between defibrillation threshold and dose–response curve 37
Patient-specific defibrillation threshold and safety margin testing 38
Clinical role of defibrillation testing at implantation 39
Management of the patient who fails defibrillation testing 41
Upper limit of vulnerability to assess safety margin 45
Drugs and defibrillators 45
Antitachycardia pacing 46
References 47
2: Hemodynamics of Cardiac Pacing: Optimization and Programming to Enhance Cardiac Function 53
Cardiovascular physiology 54
Abnormal physiology 55
Basics of hemodynamic pacing 55
Chronotropic response 55
Atrioventricular dissociation and ventriculoatrial conduction 55
Atrioventricular synchrony 57
Atrioventricular optimization 61
Principles of echocardiographic atrioventricular optimization 64
Atrial mechanical function 68
Effect of pacing mode on morbidity and mortality 68
Optimal ventricular pacing sites 73
Pacing in heart failure 78
Influence of pacing site 78
Mechanisms underlying the benefits of left ventricular and biventricular pacing 79
Left ventricular diastolic function 82
AV optimization in cardiac resynchronization therapy 82
Ventricular timing optimization (V-V optimization) 83
Optimizing site of pacing (LV and/or RV) 83
Electrical parameters for V-V optimization 84
QRS vector fusion 84
Echocardiography for ventricular timing optimization 87
Clinical approaches to V-V optimization 87
Other end-points for optimization 89
Right ventricular function 89
Cardiac contractility modulation pacing 90
Ventricular rate regulation 90
Less common indications for pacing for hemodynamic improvement 90
Pacing in hypertrophic obstructive cardiomyopathy 90
Hemodynamic benefits of pacing in neurocardiogenic syndromes 91
Hemodynamic benefits of pacing in first-degree atrioventricular block 92
Conclusions 92
Addendum 92
References 92
3: Indications for Pacemakers, ICDs and CRT: Identifying Patients Who Benefit from Cardiac Rhythm Devices 105
Indications for permanent pacing 106
Atrioventricular block 106
Acute myocardial infarction 112
Chronic bifascicular and trifascicular block 113
Sinus node dysfunction 113
Neurally mediated reflex syncope 116
Tachyarrhythmias 118
Hypertrophic cardiomyopathy 119
Congestive heart failure 119
Pacing after cardiac transplantation 124
Indications for the implantable cardioverter-defibrillator 124
Secondary prevention 125
Primary prevention 125
Contraindications to implantable cardioverter-defibrillator therapy 138
Acknowledgement 139
References 139
4: Choosing the Device Generator and Leads: Matching the Device with the Patient 145
Pacemaker selection 146
Symptomatic bradycardia 147
Pure sinus node dysfunction 148
Pure atrioventricular block 148
Neurocardiogenic syncope and carotid sinus hypersensitivity 148
Choosing specific programmable options 148
Choosing the rate-adaptive sensor 148
Choosing the lead or leads 148
Threshold reduction 149
Lead polarity 149
Electrode design 151
Lead conductor 151
Lead insulation 151
Lead diameter 152
Compatibility of lead and pulse generator 153
Epicardial leads 153
Resources for lead performance and survival data 154
Generator and lead selection in defibrillators 156
Lead design considerations for ICD leads 156
Programmable waveforms 161
Dual-chamber or single-chamber ICD? 161
Factors favoring single-chamber defibrillators 161
Factors favoring dual-chamber defibrillators 161
Specific device and lead features influencing selection 162
Conclusions 166
References 166
5: Implanting and Extracting Cardiac Devices: Technique and Avoiding Complications 169
Implantation facility 170
Anesthesia 170
The pulse generator pocket 171
Venous approaches 172
Axillary (extrathoracic subclavian) approach 172
Subclavian approach 177
Cephalic approach 177
Jugular approach 177
Iliac vein approach 178
Ventricular lead placement 178
Coronary sinus lead placement 187
Coronary sinus cannulation 188
Coronary sinus venography 193
Securing permanent leads 201
Dual-chamber pulse generator implantation 201
Measurement of pacing and sensing thresholds 204
Determination of pacing threshold 205
Determination of sensing threshold 206
Epicardial systems 208
Hardware adaptations 208
Special considerations in pediatric patients 210
Device implantation after cardiac transplantation 214
Hospital stay after implantation 215
Pulse generator replacement 215
Post-implant order set 217
Homegoing instructions 217
Lead extraction 217
Indications for lead extraction 217
Facility requirements for lead extraction 221
Outcomes of lead extraction 221
Complications of lead extraction 221
Extraction techniques 222
References 227
6: Implant-Related Complications: Relevant Anatomy and an Approach for Prevention 231
Complications related directly to the implant procedure 232
Lead dislodgement 232
Pneumothorax 235
Lead perforation 237
Pericarditis 240
Arrhythmias 240
Pulse generator pocket complications 241
Pain 242
Inadvertent left ventricular lead placement 244
Thrombosis 244
Loose connector block connection 246
Lead damage 246
Infection 247
Abandoned and nonfunctioning, noninfected leads 250
Twiddler’s syndrome 252
New symptoms secondary to pacemaker placement 257
Extracardiac stimulation 257
Pacemaker syndrome 257
Tricuspid regurgitation 257
Battery depletion 258
Implant or hardware-related complications that may result in recurrence of preimplantation symptoms (see also Chapter 10: Troubleshooting) 258
Loss of circuit integrity 258
Lead fracture and insulation defect 260
Exit block 260
References 264
7: Timing Cycles 267
Basic approach 268
Pacing modes 269
Atrial inhibited pacing 269
Single-chamber triggered-mode pacing 271
Rate-modulated pacing 271
Atrioventricular sequential, ventricular inhibited pacing (DVI) 273
Atrioventricular sequential, non-P-synchronous pacing with dual-chamber sensing (DDI) 273
Atrioventricular sequential, non-P-synchronous, rate-modulated pacing with dual-chamber sensing (DDIR) 274
Atrial synchronous (P-tracking/P-synchronous) pacing (VDD) 274
Dual-chamber pacing and sensing with inhibition and tracking (DDD) 274
Portions of pacemaker timing cycles 276
Atrioventricular interval 276
Comparison of atrial with ventricular-based timing 280
Dual-chamber rate-modulated pacemakers: effect on timing cycles 284
Mode switching 288
Avoiding atrial pace/sense competition 288
Timing components of ventricular avoidance pacing algorithms 290
Endless-loop tachycardia 291
Timing cycles with algorithms responding to sudden bradycardia 292
Timing cycles unique to biventricular pacing 293
Timing cycles in ICDs 299
Initial electrocardiographic interpretation 300
Response to magnet application 301
Single-chamber pacemakers 303
Dual-chamber pacemakers 304
Biventricular paced electrocardiogram: position, adequacy, and timing 308
Characteristic electrocardiographic patterns with specific lead locations 311
Timing intervals and the ECG 314
Electrocardiographic considerations in the patient not responding to CRT 328
Conclusions 328
References 328
8: Programming: Maximizing Benefit and Minimizing Morbidity Programming 331
Programmers 332
Pacemaker programming 332
Interrogation 333
Emergency programming 333
Programmed parameters 333
Measured data 334
Specific programmable parameters to consider in all patients 334
Unexpected programming 362
Programming during routine follow-up 369
Defibrillator programming 372
Implantable cardioverter-defibrillator sensing 374
Implantable cardioverter-defibrillator detection 378
SVT-VT discriminators 385
Ventricular therapies 402
Atrial defibrillators: detection and therapies 405
Optimizing programming 406
Cardiac resynchronization programming 407
Algorithms to promote continuous tracking 407
Algorithms to manage premature ventricular complexes 410
Algorithms to manage atrial fibrillation 411
Device-based optimization for cardiac resynchronization 411
Conclusions 412
References 413
9: Sensor Technology for Rate-Adaptive Pacing and Hemodynamic Optimization 419
Indications for rate-adaptive pacing 420
Sensors available for rate-adaptive pacing 420
Activity sensors 421
Minute ventilation sensors 423
SonR sensor (previously called peak endocardial acceleration sensor) 423
Right ventricular impedance-based sensor 424
Stimulus-T or QT, sensing pacemaker 426
Other sensors 426
Dual-sensor rate-adaptive pacing 427
Sensor applications for hemodynamic management 430
Programming 430
Programmable parameters 432
Rate-adaptive pacing with cardiac resynchronization devices 436
AV and V-V timing 436
Future of rate-adaptive sensors 437
References 437
10: Troubleshooting: Interpreting Diagnostic Information to Ensure Appropriate Function 439
Pacemaker troubleshooting 440
Clinical assessment 440
Identifying the pulse generator 441
Electrocardiographic interpretation 442
Lead integrity 442
Pulse generators 444
Clinical troubleshooting 444
Diagnostic features 451
Unexpected device failure 451
Operative evaluation of pacing systems 452
Focused troubleshooting 452
Failure to capture 453
Pseudo-malfunctions 464
Failure to pace (no output) 466
Undersensing 470
Alteration in programmed pacing rate 474
New symptoms after pacemaker implantation 476
ICD troubleshooting 484
Diagnostic tools for ICD troubleshooting 484
Evaluating appropriateness of delivered therapy 488
Determining if shocks for VT are necessary 518
Approach to the patient with frequent shocks 522
Unsuccessful shocks 523
Failure to deliver or delayed therapy: underdetection and undersensing 527
Troubleshooting ICD lead failure 533
Troubleshooting cardiac resynchronization devices 545
Failure to respond to resynchronization pacing 545
Troubleshooting other problems in CRT systems 554
References 558
11: Radiography of Implantable Devices 565
Introduction 566
Pulse generators 566
Other types of pulse generators 568
Leads 570
Pacemaker leads 572
Transvenous atrial leads 576
Transvenous ventricular leads 579
Epicardial leads 584
ICD leads 584
Epicardial ICD leads 584
Transvenous ICD leads 584
Coronary venous leads 589
Miscellaneous considerations 595
Conclusions 597
References 600
12: Electromagnetic Interference: Sources, Recognition, and Management 603
Pacemaker responses to noise 605
Asynchronous pacing 605
Mode resetting (power-on reset, or electrical reset) 609
Environmental electromagnetic interference 610
References 623
13: Follow-up 625
Requirements for a device follow-up clinic 626
Space 626
Personnel 626
Equipment 627
Pacemaker follow-up 628
Trans-telephonic monitoring 628
Equipment 628
Trans-telephonic monitoring sequence 629
Internet-based remote monitoring 630
Pacemaker clinic follow-up visit 630
ICD follow-up 638
Assessment of the patient’s clinical status 638
Pulse generator assessment 638
Capacitor status 640
Assessing lead function 642
Defibrillation efficacy assessment 643
Medications 644
Strategies to minimize shocks 646
CRT follow-up specifics 646
Remote patient monitoring 646
Medical advisories and recalls 652
Lifestyle and personal concerns 656
Psychologic issues encountered following device implantation 657
Withdrawal of device support 658
Conclusions 658
References 658
Index 663