AICD programming

In this ppt i am going to discuss about basics of AICD programming

1. Programming AICD Presenter Dr Praveen Gupta Moderator Dr Raja S elveraj Department of Cardiology 05.09.2017 JIPMER Pondicherry 1

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7. Detection and treatment of ventricular tachyarrhythmias by an ICD involves a series of sequential steps, each of which provides an opportunity to minimize unnecessary shocks 7

8. Optimal ICD programming P rogramming of the detection rate Detection duration A ntitachycardia pacing (ATP ) D iscriminate supraventricular tachycardia (SVT) from VT P rogramming to minimize the sensing of noise 8 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

9. Rate and Duration for Initial Detection ICDs detect VT/VF if the RR intervals are shorter than the detection interval for a programmable number of intervals or duration An increased detection rate or prolonged duration is the most robust programming tool for prevention of unnecessary ICD therapy 9 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

10. 10 Rate and Duration for Initial Detection Primary prevention patients experience faster VTs with rates less likely to overlap SVT than secondary prevention patients Permits programming of faster VT rate cutoffs , ,minimizes unnecessary shocks in primary prevention patients Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

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12. 12 Rate and Duration for Initial Detection PREPARE (Primary Prevention Parameters Evaluation) study The Detection rates 182 bpm , duration set for 30 of 40 intervals (≈9 seconds), patients less likely to receive a shock (9% versus 17%, P<0. .01), No difference in arrhythmic syncope between groups Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

13. SVT-VT Discrimination Withhold inappropriate therapy Hardware dependent 13 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

14. Single chamber discrimination Sudden onset Rate stability Ventricular complexes morphology 14 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

15. Single-Chamber Algorithms Sudden onset Sudden onset criterion bases action on the past 8 intervals: Takes the interval average of every other detected ventricular event (4 out of 8) Compares the current interval average to each of the four previous interval averages If the sudden onset difference is less than the programmed delta, the onset is classified as gradual, favoring sinus tachycardia. Otherwise, the onset is classified as sudden, favoring VT. 15

16. Single-Chamber Algorithms Stability The stability delta is the widest difference between the second longest and second shortest cycles, among 12 (programmable value) consecutive cycles of tachycardia detection (discards the fastest and the slowest intervals and subtracts the shortest interval from the longest interval). If the stability difference is less than the programmed delta, the rhythm is VT. Otherwise favors AF Does not, discriminate sinus tachycardia, atrial tachycardia or atrial flutter from VT. In this example: stability ignores longest (395 ms ) and shortest (268 ms ) intervals and subtracts second longest (378 ms ) from second shortest (271 ms ): 378 ms - 271 ms = 107 m (> 80 ms the programmed value); therefore interval stability indicates SVT (AF) 16

17. 17 Compare electrograms during tachycardia with a template acquired during normal rhythm Single-Chamber Algorithms Morphology

18. Single-Chamber Algorithms Morphology Tachycardia morphology similar from template by programmable threshold is SVT Example: SVT = Match (% match above 60% threshold) The algorithm breaks the waveform apart into triangular chunks and compares the A pieces, the B pieces, etc. At each point, it determines how much discrepancy there is between template and test. In this case, there is none, which results in a 100% match. In such a scenario, the algorithm would determine the rhythm was an SVT (sinus in origin) rather than a VT. 18

19. Single-Chamber Algorithms Morphology Tachycardia morphology differs from template by programmable threshold is VT Example: VT = Non-Match (35% match is less than 60% threshold) Each part is compared (A to A, B to B) etc. This drawing shows how these particular pieces do not match exactly; the far right shows areas that one waveform has and the other does not (in other words, the blue areas is the one that does not match). The MD algorithm assesses this numerically; in this case, the waveforms are only a 35% match (in favor of VT ). 19

20. Single-Chamber Algorithms Morphology algorithm greater sensitivity and specificity Sensitivity 92% to 99% and specificities of 90% to 97% Interval algorithms (onset and stability) unreliable at higher rates (>180–200 bpm Morphology is the only SVT-VT discriminator reliably applied at rates >200 bpm 20 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

21. Dual-Chamber SVT-VT Discriminators 21 Use information collected simultaneously from the atria and ventricles Dual chamber devices discriminators, depending on the AV relationship used to classify the arrhythmia (V>A, V<A, V=A). Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

22. Dual-Chamber SVT-VT Discriminators T he ventricular rate is faster than the atrial one in the majority (more than 80%) of the ventricular tachycardias or fibrillations, this proportion even increases with very fast rhythms. Therefore, the 2 other branches (V=A and V<A) apply for less than 20% of ventricular tachycardias VT arm ( V>A), When the ventricular rate is faster than the atrial rate, the tachycardia is classified as VT. No other discrimination criterion is analyzed 22

23. Dual-Chamber SVT-VT Discriminators When the ventricular rate is slower than the atrial rate, one must distinguish AF, atrial tachycardia or flutter, and VT, Rate stability Stability of AV association QRS morphology The rate stability and morphology criteria operate as described for single chamber devices. AV association operates on the same principle as rate stability, i.e. the AV association delta measures the difference between the second longest and second shortest AV intervals among the 12 tachycardia detection cycles. When Interval Stability classifies a rhythm disorder as VT, AV association goes into effect. 23 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

24. Dual-Chamber SVT-VT Discriminators 24 V entricular and the atrial rates are same, using the following criteria: AV interval delta Sudden onset QRS morphology Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

25. Dual-Chamber SVT-VT Discriminators 25 AV Interval discrimination is evaluated first. If AV interval points to VT, then no other discrimination is applied, and VT therapy begins. If AV interval points to SVT, then the rhythm is evaluated by 2 other discriminators in the V=A rate branch: the sudden onset and morphology criteria Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

26. Dual-Chamber SVT-VT Discriminators 26

27. Dual-Chamber SVT-VT Discriminators Use atrioventricular (AV) association to distinguish SVT from VT Proper atrial and ventricular sensing is essential Atrial undersensing caused by AF, lead dislodgement, functional, resulting from the atrial blanking that occurs during and immediately after ventricular sensed or paced events Atrial undersensing lead to misclassification of SVT as VT 27 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

28. Dual-Chamber SVT-VT Discriminators Oversensing by large FFRWs , misclassification of VT as SVT, inappropriately withheld therapy Prevent both far-field R-wave (FFRW) oversensing and the undersensing of small fibrillation waves on the atrial channel 28 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

29. Single- Versus Dual-Chamber ICD No benefit of dual-chamber over single-chamber D ual-chamber discrimination is superior when overlap in VT and SVT rates D ual-chamber ICDs for secondary prevention and for patients with slow VT In primary prevention patients, little overlap between SVT and VT heart rates, the benefit of using high rate cutoffs and prolonged detection appears to overwhelm any modest additional contribution of dual-chamber SVT-VT discrimination 29 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

30. Antitachycardia Pacing ATP is rapid pacing at a cycle length shorter than VT Terminates VT by penetrating the circuit ATP terminate slow VT (<188–200 bpm ), Success 85 % to 90% and a 1% to 5% risk of acceleration VT in primary prevention are monomorphic, potential application of ATP 30 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

31. ATP 31 R ate of ATP programmed at 69% to 88% of VT cycle length Each drive train typically has 8 stimuli F irst ATP most effective, 95 % of responsive fast VTs terminated successfully Only a small minority of patients are responsive to >3 or 4 ATPs Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

32. Factors affecting efficacy of ATP Burst ATP- Interstimulus interval in the train remains constant Ramp ATP-Each subsequent stimulus in a train is decremented Burst and ramp pacing have similar efficacy and safety for slow VT Fast VT, burst pacing 32 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

33. Redetection and Reconfirmation Contemporary devices reconfirm the persistence of arrhythmia during and after charging. Charge is dissipated if arrhythmia terminates Noncommitted shock if possible The ADVANCE-CRT trial reported greater efficacy of biventricular ATP in patients with ischemic cardiomyopathy. 33 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

34. Antitachycardia Pacing Analysis of the response to ATP Used to optimize programming Provides measure of temporal proximity of the pacing site to the VT D ifferential diagnosis of SVT and VT Transient VA and AV block during ATP is diagnostic of VT and SVT, respectively An AAV response is diagnostic of atrial tachycardia, and a VVA response is diagnostic of VT 34 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

35. Programming Therapy Zones ICDs have 2 to 3 zones defined by the longest RR interval in each zone The lower boundary between sinus and VT zone is programmed at approximately 180 to 188 bpm in primary prevention patients and at 30 to 60 ms greater than the cycle length of the slowest observed VT (150–160 bpm in most trials) in secondary prevention patients Programming in the VT zone is focused on preventing therapy for SVT and nonsustained VT 35 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

36. Programming Therapy Zones If 2 VT zones are programmed, the rate at which fewer trials of ATP therapy are desired forms the boundary between the 2 zones. In secondary prevention, slower VT zone is programmed with 3 to 4 sequences of ramp/burst ATP compared with 1-burst ATP followed by shocks in the faster VT zone. SVT discriminators are programmed on in VT zones. Implantable cardioverter defibrillator (ICD) rate detection zones. Some ICDs permit programming of an additional monitor-only zone. The upper panel shows programming for secondary prevention patients. The lower panel shows programming for primary prevention patients. 36 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

37. Programming Therapy Zones The boundary between the VT and VF zones is determined by the rate at which ATP before charge is no longer desired SVT discriminators are either not programmable in the VF zone (Boston Scientific and St Jude Medical) or are applied with some limitations (Medtronic ) 37 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

38. ATP should not be routinely programmed 38 Inherited channelopathies (Brugada syndrome, Long and Short QT syndrome) C atecholaminergic polymorphic VT E arly repolarization syndromes A rrhythmia is polymorphic VT or VF A rrhythmias lack reentry and not interrupted by pacing

39. Shock Strength, Polarity, and Defibrillation Threshold 39 Implant testing assesses VF sensing and defibrillation effectiveness SAFE-ICD study (Safety of Two Strategies of ICD Management at Implantation) revealed comparable rates of ICD complications and long-term sudden death in patients who did and did not undergo routine DFT testing Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

40. Shock Strength, Polarity, and Defibrillation Threshold Strongly considered in nonstandard lead positioning, right-sided devices, amiodarone therapy, pediatric implantations, and use of an s-ICD 40 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

41. Shock Strength, Polarity, and Defibrillation Threshold If the DFT is known, the first shock in the VT zone is programmed ≥10 J above it, and subsequent shocks are set to maximal energy The advantage of lower-energy shocks (conservation of battery life, diminished postshock stunning or block) is minimal with current biphasic technology. High-energy shocks are more likely to be successful for VT/VF and SVT without patient discomfort or increase in charge time Low-energy shocks also convey a risk of conversion of VT to VF Maximal shock strength is generally preferred 41 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

42. Shock Strength, Polarity, and Defibrillation Threshold R ight ventricular coil as the anode resulted in slightly lower DFT in some patients Reverse-shock polarity, can be tried in patients with high DFTs. 42

43. Optimization of Sensing to Prevent Shocks 43 ICD should reliably sense every QRS complex during normal rhythm and small fibrillatory waves during VF D o not sense T waves I gnore extracardiac and nonphysiological signals ICDs use dynamic sensitivity or gain to achieve these sensing requirements Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

44. Optimization of Sensing to Prevent Shocks After a sensed or paced ventricular event, sensitivity is reduced as a function of the amplitude of the R wave after the postventricular blanking period expires. S ensitivity is increased until a subsequent event is sensed or the maximum programmed sensitivity is reached S trategy reduces r isk of T-wave oversensing while maintaining sensitivity for the small deflections of VF 44 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

45. Preventing T-Wave Oversensing 45 Low-amplitude R waves (<3 mV), large T waves, or long QT intervals promote T-wave oversensing , result in double counting and inappropriate therapy . Hypertrophic cardiomyopathy, long-QT syndrome, and Brugada syndrome predispose T-wave oversensing Decreasing ventricular sensitivity reduces the risk of T-wave oversensing but requires a sufficiently large R- to T-wave ratio and may risk VF undersensing Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

46. Surveillance of Lead Fracture Lead Integrity Alert algorithm for detection of lead fracture based on sudden changes in lead impedance and noise detection The lead-integrity alert is triggered if 2 of 3 events occur: ( 1) Sudden increase in lead impedance ( 2) ≥2 nonsustained tachycardia events (≥5 beats) with intervals <220 ms (3 ) sensing integrity counters with ≥30 short RR-interval counts <140 ms within 3 consecutive days indicative of nonphysiological signals 46 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

47. Noise-Detection Algorithms Algorithms for discrimination of VT from myopotentials and nonphysiological noise such as electromagnetic interference N oise have higher frequency with very short intervals If noise is detected, the device raises the floor of the dynamic sensitivity above the level of the noise to prevent oversensing This is most useful to prevent myopotential detection 47 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

48. ICD Programming During Electrical Storm Recurrent ICD shocks in the course of electrical storm (defined as ≥3 VT/VF episodes in 24 hours) Lead to heart failure, sympathetic overdrive, and psychological trauma, which potentiates the risk for recurrent VT. 48 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

49. ICD Programming During Electrical Storm 49 Programming for minimizing the number of shocks Duration to detection is increased Number of intervals to declare an end of episode decreased Increasing the lower pacing rate may help suppress recurrent VT/VF Hospitalized patients, ICD therapies are turned off during electrical storm Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

50. Remote Monitoring Automated , wireless remote monitoring with clinician and patient alerts shortens the time to detection of changes in clinical status and device function and may reduce mortality risk 50 Madhavan M, Friedman PA. Optimal programming of implantable cardiac-defibrillators. Circulation. 2013 Aug 6;128(6):659-72.

51. Conclusions Proper ICD programming minimizes unnecessary ICD therapy to reduce patient morbidity and mortality . Current evidence supports the use of various strategies to reduce shocks without compromising therapy effectiveness. The extension of detection duration to prevent treatment of self-terminating tachycardia has proven to be the most useful of these strategies, followed by the application of SVT-VT discrimination and the use of ATP to terminate VT 51

52. Disclosures Dr Friedman has received research support from Medtronic (grant administered by Mayo Clinic for investigator-initiated study), Biotronik , and Cameron Health, and is a speaker or consultant for Bard, Biotronik , Leadex , and Sorin . Dr Madhavan reports no conflicts 52

53. 53 Thank You