Workshop #5 VT and ICD Unknowns

1. Workshop #5VT and ICD Unknowns Chair: David J. Wilber, MD Faculty: John P. DiMarco, MD, PhD Francis E. Marchlinski, MD

2. Case #7 • A 15 year old African-American man is evaluated because of exertional dyspnea. His baseline ECG and a response to a PVC are shown. The response to 6 mg iv adenosine at EP study is shown in the third figure. • Which of the following statements concerning the mechanism for tachycardia termination is correct: • Block occurred in a slow AV nodal pathway • Block occurred in a fast AV nodal pathway • Both anterograde and retrograde AV nodal block occurred • Block occurred in an accessory pathway • Block occurred in the His-Purkinje system

6. Case #7 Answer • Which of the following statements concerning the mechanism for tachycardia termination is correct: • Block occurred in a slow AV nodal pathway • Block occurred in a fast AV nodal pathway • Both anterograde and retrograde AV nodal block occurred • Block occurred in an accessory pathway • Block occurred in the His-Purkinje system This question is an extension of the previous one. It just shows block with adenosine during retrograde conduction in the accessory pathway. Note that the immediate resumption in the right-hand part of the tracing.

7. Case #8 • Which of the following is the most likely diagnosis for the arrhythmia shown below? • Atrial tachycardia • AV reentrant tachycardia • Sinus tachycardia • AV nodal reentrant tachycardia • Automatic junctional tachycardia

9. Case #8 Answer • Which of the following is the most likely diagnosis for the arrhythmia shown below? • Atrial tachycardia • AV reentrant tachycardia • Sinus tachycardia • AV nodal reentrant tachycardia • Automatic junctional tachycardia An early PVC advances the atrium. The next beat is a typical AV nodal echo beat. Note that there is 2:1 block during the tachycardia in the left-hand portion of the tracing. Even when the A is advanced by the early PVC, the next beat looks like a typical slow-fast AV nodal echo.

10. Case #9 • These 3 tracings were obtained at EP study in a 23 year old white woman with recurrent palpitations. Which of the following circuits is used in the tachycardia shown? • AnterogradeRetrograde • AV node-His with LBBB Left Acc Pathway • AV node-His with LBBB Septal Acc Pathway • Anteroseptal Acc Pathway Left Acc Pathway • Atriofascicular Tract His- AV node • Right Post Acc Pathway His-AV node

12. Case #9 Answer • Which of the following circuits is used in the tachycardia shown? • AnterogradeRetrograde • AV node-His with LBBB Left Acc Pathway • AV node-His with LBBB Septal Acc Pathway • Anteroseptal Acc Pathway Left Acc Pathway • Atriofascicular Tract His- AV node • Right Post Acc Pathway His-AV node Tracing 9-1 shows SR with a slight degree of anterograde preexcitation with a delta wave polarity that suggests a left sided AP. This was never involved in tachycardia. Tracing 2 shows a regular tachycardia with a left bundle block morphology consistent with either aberration, an atriofascicular tract or a right sided AP for anterograde conduction. In the intracardiac recordings we see that retrograde conduction is over midline structures, probably the AV node-HPS. Since we don’t see any evidence for a right sided AP in sinus rhythm, this is most consistent with an atriofascicular tract.

13. Case #10 • 42 y/o women with sustained palpitations + presyncope • Baseline ECG and SAECG, ECHO normal. • Palpitations with exercise and during premenstrual period • 12 lead ECG at time of exercise test is shown

15. Case 10: Question 1 • What is the likely arrhythmia diagnosis? • VT due to RV dysplasia • Idiopathic LV VT • Bundle branch reentrant VT • SVT with aberration • Repetitive monomorphic outflow tract tachycardia

16. Case #10: Question 1 Answer What is the likely arrhythmia diagnosis? • VT due to RV dysplasia • Idiopathic LV VT • Bundle branch reentrant VT • SVT with aberration • Repetitive monomorphic outflow tract tachycardia The absence of structural heart disease plus the ECG features of the arrhythmia are most consistent with the diagnosis of RVOT VT. There is no evidence of RV dilatation or other abnormalities consistent with RV dysplasia. The LBBB morphology in the absence of structural heart disease is inconsistent with idiopathic LV VT. The inferior rightward axis is inconsistent with bundle branch reentry. The same logic applies to excluding the diagnosis of SVT with LBBB aberration.

17. Case 10: Question 2 What is the “best” evaluation /treatment option? • Electrophysiologic study with introduction of single and double extrastimuli to induce arrhythmia and establish diagnosis? • Implantation of an ICD device with antitachycardia pacing capabilities. • Institution of beta blockade therapy and repeat exercise testing to assess efficacy • Institution of beta blockade therapy and schedule programmed stimulation to assess efficacy

18. Case 10: Question 2 Answer What is the “best” evaluation /treatment option? • Electrophysiologic study with introduction of single and double extrastimuli to induce arrhythmia and establish diagnosis? • Implantation of an ICD device with antitachycardia pacing capabilities. • Institution of beta blockade therapy and repeat exercise testing to assess efficacy • Institution of beta blockade therapy and schedule programmed stimulation to assess efficacy

19. Case 10 Comments The electrophysiologic study is not required to establish the diagnosis. However, it would not be inappropriate to perform the study. ( i.e, not the best evaluation/treatment option). RVOT tachycardias typically require burst pacing and/or isoproterenol infusion for initiation in the EP lab and is initiated with extrastimuli in ~ one third of the patients. . RVOT VT usually responds to Beta-blockers and less commonly verapamil. Repeated exercise testing best assesses the respone to drug treatment of arrhythmias like RVOT VT that are triggered by exercise and precipitated during exercise testing. ICD therapy is inappropriate. Role of EP testing is primarily related to ablative therapy .

20. Case 10: Continued • Patient had recurrent arrhythmia symptoms (palpitations with presyncope) on antiarrhythmic drug therapy • propranolol LA 120 mg • Toprol 100 mg + verapamil 90 mg bid • sotalol 80mg tid • Increase in fatigue and ability to concentrate with described dose of beta blockers • Constipation with verapamil

21. Case 10: Question 3 Acceptable treatment option(s) for this patient’s arrhythmia include? • Implantation of an ICD device with antitachycardia pacing capabilities. • Start amiodarone therapy • Increase dose of Beta blocker to achieve therapeutic efficacy • Reduce exercise and advice hormone replacement therapy to decrease premenstrual arrhythmia symptoms • Catheter ablative therapy to attempt arrhythmia cure with anticipated success of >90%

22. Case 10: Question 3 Answer Acceptable treatment option(s) for this patient’s arrhythmia include? • Implantation of an ICD device with antitachycardia pacing capabilities. • Start amiodarone therapy • Increase dose of Beta blocker to achieve therapeutic efficacy • Reduce exercise and advice hormone replacement therapy to decrease premenstrual arrhythmia symptoms • Catheter ablative therapy to attempt arrhythmia cure with anticipated success of >90%

23. Case 10 Question 3 Comments Catheter ablation guided by pacemapping/activation mapping is the most appropriate choice The use of the ICD in this patient who is not at risk for sudden death is inappropriate. Amiodarone is a poor choice given the risk of adverse effects. The patient is already experiencing some side effects from her better blockers. Although women may experience an exacerbation of RVOT-VT during the premenstrual period, with pregnancy and with menopause, it has not been documented that hormonal therapy is beneficial.

24. Case 10: Question 4 The patient would like to consider catheter ablative therapy- which of the following statements is true regarding ablative therapy for her arrhythmia? • Based on analysis of the 12 lead ECG, the origin of the arrhythmia is near the superior aspect of the tricuspid valve • Catheter ablation should not be attempted, the tachycardia is epicardial in location and can only be approached surgically. • Multiple VT morphologies are likely to be induced with programmed stimulation • The arrhythmia will likely be induced only after the administration of procainamide • None of the above

25. Case 10: Question 4 Answer The patient would like to consider catheter ablative therapy- which of the following statements is true regarding ablative therapy for her arrhythmia? • Based on analysis of the 12 lead ECG, the origin of the arrhythmia is near the superior aspect of the tricuspid valve • Catheter ablation should not be attempted, the tachycardia is epicardial in location and can only be approached surgically. • Multiple VT morphologies are likely to be induced with programmed stimulation • The arrhythmia will likely be induced only after the administration of procainamide • None of the above

26. Case 10 Question 4 Comments The tachycardia origin is anterior and superior RV septum just under the pulmonic valve near the junction with RV free wall. Note, a prominent R wave in V3 suggests a possible LV epicardial location which may be difficult to access from the RV. Of note, the tachycardia was successfully ablated from the RV in this patient. Characteristically, only a single VT morphology is noted. Uncommonly, patients have multiple morphologies of outflow tract tachycardias. Procainamide is not used to enhance inducibility of this arrhythmia

27. RAO VT Ablation LAO PACEMAP Ablation

28. Case 10: Question 5 The following is(are) true concerning the previous figures recorded at the time of attempted catheter ablation? • The catheter site is septal and posterior in the RVOT • Application of RF energy at site shown on the xray will probably be ineffective in ablating VT • Recording of the activation time during VT is necessary to determine the appropriateness of this site for catheter ablation • None of the above • All of the above

29. Case 10: Question 5 Answer The following is(are) true concerning the previous figures recorded at the time of attempted catheter ablation? • The catheter site is septal and posterior in the RVOT • Application of RF energy at site shown on the xray will probably be ineffective in ablating VT • Recording of the activation time during VT is necessary to determine the appropriateness of this site for catheter ablation • None of the above • All of the above The ablation catheter is located at the upper margin of the RV in the RVOT region as noted in the RAO projection. The pacemap is very similar to the tachycardia morphology suggesting that the catheter is at a site that will probably result in effective catheter ablation. Although the activation mapping and unipolar recordings have been used by some operators/investigators, multiple reports have documented the success of pacemapping. The activation time and unipolar electrogram information should provide helpful corroborative information to the information obtained during pacemapping , i.e., Always use all the information available to document the appropriate site for catheter ablation.

30. Case #11 50 y/o with CAD and prior MI with recurrent hemodynamically tolerated VT. Patient experiences four ICD shocks (Each two shocks separated by two hours) without arrhythmia symptoms shortly after implant. Pt is upset and requests that device be removed. ECG recording of one of the two identical episodes is shown. Defibrillation threshold at time of ICD implant was 22J. • Begin sotalol with repeat evaluation/reprogramming of ICD device prior to discharge • Catheter ablative therapy to eliminate frequent VT occurrence • Start empiric amiodarone and schedule for repeat ICD evaluation in 12 mos. • Reprogram ICD to incorporate additional bursts of ATP and increase output of first ICD shock Which recommendation for management of the patient is LEAST favorable?

31. VT ZONE 150 – 190bpm 5J 30J

32. Case #11 Answer Which recommendation for management of the patient is LEAST favorable? • Begin sotalol with repeat evaluation/reprogramming of ICD device prior to discharge • Catheter ablative therapy to eliminate frequent VT occurrence • Start empiric amiodarone and schedule for repeat ICD evaluation in 12 mos. • Reprogram ICD to incorporate additional bursts of ATP and increase output of first ICD shock

33. Case 11 Comments • Ineffective ATP and ineffective low energy first shock has been documented. • At the very least additional bursts of ATP and an increase in the first shock energy would be appropriate. • Administration of sotalol plus repeat ICD evaluation would also be appropriate. • Given the patients concern about arrhythmia recurrence, catheter ablative therapy targeting the clinical arrhythmia would also be appropriate. • Institution of amiodarone, which can increase DFT and slow the rate of VT below rate cut off, should be followed by ICD assessment in a more timely fashion (one to two months) to guarantee appropriate device programming. • A repeat evaluation at a later point, typically 6 mos, may also be in order to identify delayed effects on DFT and VT cycle length from amiodarone.

34. Case #12 See next page for ICD programming

35. 12-2

36. ECG recorded after device reprogrammed to pacing rate of 75 bpm.

37. Case 12 Question 1 The best explanation for the observed ECG events? • Intermittent oversensing of diaphragmatic contraction • Intermittent lead failure • Intermittent failure to capture • Intermittent T wave sensing • None of the above

38. Case #12: Question 1 Answer The best explanation for the observed ECG events? • Intermittent oversensing of diaphragmatic contraction • Intermittent lead failure • Intermittent failure to capture • Intermittent T wave sensing • None of the above Ventricular pacing at rates below the programmed bradycardia pacing is demonstrated. Oversensing is present. The rate and regularity of the pacing is consistent with sensing of T wave. After reprogramming pacemaker to rate of 75, sensing of the T wave persists.

39. CASE #13 58 y/o man with history of HTN, coronary artery disease/ prior MI(LVEF of 30%), hospitalization for CHF, recurrent VT(rate 160 to 180) and ICD with effective ATP documented 2 years ago. Now with recurrent ICD shocks. ECG at time of ICD shock recorded during hospitalization is shown below. Arrhythmia spontaneously terminated. Stored electrograms from ICD show previous events over last two months consistent with same ECG diagnosis. PMHX. Hx of severe bronchaspastic pulmonary disease. Pulmonary infiltrate in the past which resolved when amiodarone was stopped. Current meds: furosemide 80mg bid, slow K 20mEq bid, digoxin .125mg, Calan SR180mg qd, Inhalers

40. 13-1

41. What is/are best treatment option(s) from list below? A. Add propranolol 40 mg tid B. His Bundle ablation and upgrade to DDDR ICD device to enhance automatic diagnostic capabilities and mode switching C. Restart amiodarone D. Reprogram ICD rate cut off to exceed the most rapid response to a fib (185bpm) with close follow-up E. 3 or 4 appropriate choices Case 13: Question 1

42. What is/are best treatment option(s) from list below? Case 13: Question 1 Answer • A. Add propranolol 40 mg tid • B. His Bundle ablation and upgrade to DDDR ICD device to enhance automatic diagnostic capabilities and mode switching • C. Restart amiodarone • D. Reprogram ICD rate cut off to exceed the most rapid response to a fib (185bpm) with close follow-up • E. 3 or 4 appropriate choices Patient has a history of severe bronchospastic lung disease and pulmonary infiltrates with amiodarone therapy. This information would make beta blockade therapy and amiodarone therapy poor choices in this patient. The rapid regular response during atrial fibrillation suggests that a poor response to low dose beta blockade therapy with respect to rate control may be observed. Of note the patient has a history of VT at rates less than 185 bpm. Reprogramming the ICD to exclude therapy for those VT is ill advised.

43. CASE #14 67 y/o man with CAD prior IMI/AMI, CHF (stable on meds), VT with ICD epicardial patches and epicardial screw in leads ICD at end of life and noise detected on rate sensing leads. Antiarrhythmics: Amiodarone 300mg alternating with 400mg/day times 4 years for recurrent arrhythmias/previous transplant evaluation /no recent VT episodes -NTL ICD implanted - DFT 24J with reverse polarity. Postop rechecked DFT because of borderline values intraop . -Repeated 31J shocks ineffective. External shocks required second time with 6 external shocks - lead position, impedance and noninvasive measurements not significantly changed from baseline.

44. Case 14 Continued -Cath LVEDP-22, EF-18% no active CAD -Patient brought back to the OR – anesthetized with propofol for ICD procedure - patch leads incorporated in shocking system - DFT >30J / multiple 500J external shocks required for defib ; After repeat attempt with different configuration and again repeated 500J shocks required for defibrillation procedure terminated with ICD generator attached to NTL system (reverse polarity). -Patient referred to your institution for cardiac transplant - transplant team unable to get variance to speed transplant and requests your reconsideration of options that might still result in effective defibrillation. - X- ray shows that patch leads are anterior and posterior in location with LV apex exposed.

45. Case 14 Question Your younger EP colleague provides some suggestions and you indicate your approval for all but which of the following: • Stop amiodarone under close observation with high energy external defibrillator available. • Add a low dose of sotalol - 40mg tid • Plan for placement of subcutaneous shocking lead array over the apical region • Have highest energy ICD unit available at next implant/testing • Avoid propofol anesthesia at the time of testing because it may be increasing the defibrillation threshold

46. CASE #14 Answer Your younger EP colleague provides some suggestions and you indicate your approval for all but which of the following: • Stop amiodarone under close observation with high energy external defibrillator available. • Add a low dose of sotalol - 40mg tid • Plan for placement of subcutaneous shocking lead array over the apical region • Have highest energy ICD unit available at next implant/testing • Avoid propofol anesthesia at the time of testing because it may be increasing the defibrillation threshold

47. Case 14 Comments Patient has potentially ineffective device with unanticipated increase in DFT. Increase in DFT probably not true increase but rather indicative of shallow slope of DFT curve, which relates shock energy to efficacy in defibrillation. Epicardial patches can produce an increase in energy requirement for both external defibrillation and internal – nonthoracotomy defibrillation. Any attempt to lower DFT by incorporating patch leads in shocking system should be made after ruling out a potential role for ischemia. Although not tested in detail, propofol does not appear to increase DFTs. All other recommendations are reasonable and may modestly reduce DFT. Of note, sotalol’s Class 3 effect on lowering DFT may not be evident when dose is only 40mg b.i.d. Also, change in DFT with only modest reduction in amiodarone dose may not be evident. Importantly, changes in drug therapy, in addition to other maneuvers such as appropriately placed shocking leads ( subQ array), changing polarity, +/-pulse width, may all contribute to modest lowering in DFT in selected patients. It is imperative that one have available a high energy output (34 –38J delivered for typical impedance values) ICD device.