L’Ablazione delle aritmie ventricolari

1. L’Ablazione delle aritmie ventricolari Luigi Padeletti Montecatini T.me, 14 Novembre 2007

2. Techniques for Ablation of VT • Original experience in catheter ablation of VT based on etablished criteria gained in - previous era of diagnostic electrophysiology - initial experience on RF ablation of regular supraventirular tachycardias Introduction

3. Techniques for Ablation of VT • Heterogeneity of substrates • Limits of lesion size produced by sources of energy delivered from the endocardium relative to the width and depths of the ventricular arrhythmogenic substrate Methodological perspective optimal substrate: focal source, subendocardial location!

4. Techniques for Ablation of VT Classification VT in the absence of apparent heart disease VT in the presence of heart disease • post-infarction VT • non-infarction VT substrates • ARVD • dilated CMP • congenital HD • valvular HD • ILVT • RVOT • LVOT • Focal VT in other locations • VT originating from outside • the ventricles

5. Techniques for Ablation of VT Criteria to discriminate the arrhythmogenic mechanism Automaticity Triggered activity Reentrant • Eccentric propagation from • electrical source of earliest • activation • Intracardiac electrical • activation scanning • less than the tachy CL • Positive to entrainment • maneuvers • Intracardiac electrical • activation scanning the • entire tachy CL relevant to localize the arrhythmogenic source!

6. Techniques for Ablation of VT • Techniques to enlarge lesion size (8-mm tip, cooled tip, irrigated cooled tip) • Techniques to display on accessible operational tools the 3-D anatomy of the VT substrate (Carto, En-Site, Loca-Liza…) Developmental pathways

7. Techniques for Ablation of VT Carto mapping Methodological options Advantages • Activation map • Propagation map • Voltage map • 3-D re-construction of • activation wave-front (VT, SR) • Identification of • scar tissue • areas w/ low voltage • areas w/ slow conduction limit: sequential mapping required!

8. Post-Infarction VT S S S Cappato & Kuck, 2000

9. Mappaggio elettroanatomico • Consente la caratterizzazione delle • aree cicatriziali (scar) nel VD/VS • Mappaggio di aritmie sostenute e tollerate • Utilizzabile per effettuare ablazione lineare • della “scar” • Utilizzabile per il mappaggio del • versante endocardico o epicardico

10. Techniques for Ablation of VT En-Site mapping Methodological options Practical fall-backs - Propagation map • 3-D re-construction of • activation wave-front (VT, SR) • using a single beat • (ablation of unstable VT possible!) limit: accuracy of 3-D re-construction and catheter navigation!

11. En-Site Mapping 220 ????

12. Mappaggio noncontact • Ricostruzione virtuale dell’ endocardio del • ventricolo destro/sinistro • Valutazione del pattern di attivazione dell’ endocardio • Individuazione di aree con attivazione tardiva o propagazione lenta • Analisi dell’ elettrogramma unipolare locale in RS • Analisi del pattern di attivazione (sito di uscita endocardico e • percorso diastolico) di camera durante: • -TV non sostenute o non tollerate • -TV polimorfe • -Molteplici morfologie di TV

13. RFCA of VT in CMP and ARVD Introduction Histopathology of ablation • In pts dying early after RFCA of VT, • lesion size ranges from 2 - 5 mm to almost 2 cm bands (depending on number of RF applications) • Lesion depth ranges from 1 to 5 mm and deepens within partially scarred regions relative inadequacy of energy source (RF) and approach (endocardial) to the totality of potential target substrates!

14. RFCA of VT in CMP and ARVD Introduction Location of arrhythmic substrate • Endocardial • Intramural • Epicardial

15. RFCA of VT in CMP and ARVD Introduction Noninfarction VT substrates • Substantial differences • between different noninfarction substrates and post-infarction substrates • among different nonifarction substrates EP similarity, when uniform morphology VT occurs!

16. RFCA of VT in CMP and ARVD Electrophysiologic substrate Characteristics in noninfarctionVT patients • Macroreentrant VT • endocardial diastolic activity in SR and during arrhythmia • Focal activity in up to 1 / 5th of pts with CMP • Specific locations for some noninfarction CMP of recognized mechanisms (ex., bundle branch reentrant VT in dilated CMP) different ablation techniques and success rates!

17. RFCA of VT in CMP and ARVD Electrophysiologic substrate Characteristics in noninfarction VT patients prevalence success Underlying mechanisms • Macroreentrant VT 62% 60% • Focal activity 27% 86% • BB reentrant VT 19% 100% Delacretaz et al, 2000

18. RFCA of VT in CMP and ARVD Bundle-branch reentrant VT • Tipically found in pts with dilated CMP • Usually with LBBB morphology, but RBBB also possible • Preliminary data suggest that in LBBB variant the viability of LA fascicle is essential for macro-reentry

19. Bundle Branch Reentrant VT

20. Hsia et Marchlinski, 2002

21. RFCA of VT in CMP and ARVD Bundle-branch reentrant VT • High success rate with RF applied to the endocardial sites recording the earliest RB potential • If LBBB VT, RF applied to the endocardial sites recording the earliest RB potential

22. RFCA of VT in CMP and ARVD Bundle-branch reentrant VT • If LBBB present during SR, RF applied to the endocardial sites recording a LB potential (to prevent III degree AV block)

23. RFCA of VT in CMP and ARVD Characterization of the substrate • In comparison to post-infarction VT, • focal activity (automaticity, triggered activity, micro-reentry) possibly limited to poorly accessible areas • possible absence of identifiable scar tissue • evolutional changes of underlying substrate • (new substrates may develop over time)

24. RFCA of VT in CMP and ARVD Conclusions • Compared to regular SVT, RF ablation of VT associated with CMP and ARVD • less effective • is associated with higher rate of major complications • requires more complex mapping to match the variability and complexity of substrates

25. Ablation of postinfarction ventricular tachycardias non inducible VT; unstable VT; VF stable monomorphic VT mapping during VT substrate mapping in SR mapping of triggering ectopies reentry focal analysis of the reentry circuit and identification of critical SCZ substrate ablation in SR ablation of triggers site of earliest activation

26. RFCA of PIVT based on VT mapping Abl+ Abl- Abl+/- EF>30% EF<30% Della Bella et al. Eur Heart J 2002

27. Conventional RFCA for VT – An overview Della Bella De Ponti Salerno Eur Heart J 2002 124 73% 7.2% 19% 41.5 mos 21% 9.6% 2.4% BorgerVanDerBurg - Schalij JCE 2002 151 83% 7% 22% 34 mos 26% 7.2% 0.6% O’Donnell Furniss Eur Heart J 2002 112 (30un) 84-38% 6% 23% 61 mos 22% 11.6% 1.7% Journal Year No. Pts. Success Complication Use of ICD FU duration Recurrences Non SCD SCD-FU

28. Incessant vs paroxysmal VT p n.s. n.s. n.s. <0.05 n.s. n.s. <0.01 n.s. pVT 97 62±8 94% 29/60/11 1.9 407 ± 81 23% 16% iVT 27 63±11 96% 25/40/35 1.7 412 ± 83 62% 22% No. patients Age (years ± SD) Sex (M) Site of MI (%a/i/m) No. VT morphol.s/pt Mean VT cl (ms) Pts with EF < 30% Pts with ICD

29. Incessant vs paroxysmal VT p 0.63 0.35 0.41 0.82 0.73 iVT 78% 8±6 34±24’ 188±51’ 7.4% pVT 72% 10±8 40±25’ 191±53’ 6.1% Acute success No. RF pulses Fluoro time Procedure dur. Postablation ICD

30. Ablation of postinfarction ventricular tachycardias non inducible VT; unstable VT; VF stable monomorphic VT mapping during VT substrate mapping in SR mapping of triggering ectopies reentry focal analysis of the reentry circuit and identification of critical SCZ substrate ablation in SR ablation of triggers site of earliest activation

31. Novel mechanism of PIVT originating in surviving left posterior Purkinje fibers Bogun et al. JACC 2006 Hayashi et al. Heart Rhythm 2006

32. PIVT originating from surviving Purkinje fibers Reithmann JCE Aug/07 8* 1 3 n.r. 430±49 8 3 - Pur. Pot 7/8 0 Bogun JACC Dec/06 9 3 8 4.7±4.1 yrs 402±82 7 1 1 Pur. Pot 9/9 0 Hayashi HR Aug/06 4 2 2 4dys-17yrs 472±27 2 1 1 Pur. Pot 4/4 0 Journal Year No. Pts. Prior MI -ant -inf Time from MI VT CL (ms) VT morphology -RBBBM+LS -RBBBM+RS -LBBBM Abl. Target Success New cond. dist. * Only 3 with prior myocardial infarction

33. Ablation of postinfarction ventricular tachycardias non inducible VT; unstable VT; VF stable monomorphic VT mapping during VT substrate mapping in SR mapping of triggering ectopies reentry focal analysis of the reentry circuit and identification of critical SCZ substrate ablation in SR ablation of triggers site of earliest activation

34. Linear ablation lesions for control of unmappable ventricular tachycardia in patients with ischemic and nonischemic cardiomyopathy Marchlinski et al. Circulation 2000

35. How long should be the line? Defining electrically unexcitable scars 15.9 cm Soejima et al. Circulation 2001 Soejima et al. Circulation 2002 79% 21%

36. Substrate mapping vs. tachycardia mapping using CARTO in patients with coronary artery disease and ventricular tachycardia: impact on outcome of catheter ablation Volkmer et al. Europace 2006

37. Substrate mapping vs. tachycardia mapping using CARTO in patients with coronary artery disease and ventricular tachycardia: impact on outcome of catheter ablation Volkmer et al. Europace 2006

38. Ablation of postinfarction ventricular tachycardias non inducible VT; unstable VT; VF stable monomorphic VT mapping during VT substrate mapping in SR mapping of triggering ectopies reentry focal analysis of the reentry circuit and identification of critical SCZ substrate ablation in SR ablation of triggers site of earliest activation

39. Marrouche NF et al, JACC 2004

40. Conclusive remarks • Ablation in combination with ICD is a valuable therapeutic option to treat ventricular tachycardias in patient with ischemic heart disease • The introduction of new technologies and the development of different approaches allow treatment of a wide range of arrhythmias encoutered in patients with ischemic heart disease • This results in improvement of the acute and mid-term outcome in these patients • Patients with incessant forms or electrical storms of fast ventricular arrhythmias are no longer lost cases, but can be successfully treated by ablation