1. Epicardial Ablation: Another route to be arrhythmia free John R Onufer MD FHRS

2. Epicardial Ablation  Scar related Ventricular tachycardia  Accessory pathways  Atrial fibrillation  Idiopathic Ventricular tachycardia  Outflow tract  Non ischemic cm  Sarcoid  Chagas  ARVD

3. Afib Hybrid lesion set

4. ECG of a PVC originating in the epicardium. Baman T S et al. Circ Arrhythm Electrophysiol 2010;3:274- 279 Copyright © American Heart Association

5. Left, Venogram of the great cardiac vein (GCV). Baman T S et al. Circ Arrhythm Electrophysiol 2010;3:274- 279 Copyright © American Heart Association

6. Table 2 Steps taken preprocedurally and intraprocedurally during a case of epicardial access Preprocedural Decide on the likelihood/need for epicardial access 1. Obtain a history of prior cardiac surgery, pericarditis, or pericardial instrumentation 2. Ensure normal coagulation parameters 3. Have surface or preferably intracardiac echocardiography available 4. Obtain a typed blood sample 5. Ensure access to a cardiac surgical team on short notice 6. Intraprocedural Obtain baseline imaging of the pericardial space before obtaining epicardial access 7. Routine double wiring of the pericardial space 8. Use of soft tipped sheaths/do not leave sheath tip exposed 9. Periodic survey of pericardial space by ICE 10 Periodic drainage of the intrapericardial sheath, with or without use of pig-tail catheter ICE Intracardiac echocardiography catheter.

7. Epicardial Access  18g 15cm Epidural spinal needle .032 wire  Contrast injection  Minimize contrast or will obscure view  Echocardiographic monitoring  Soft tip sheaths  Double wiring the access site  Keep sheath occupied with pig tail catheter wire or ablation catheter as sheath can lacerate epicardial vessels or RV

11. Epicardial access  Left of xiphoid process  Aim to mid clavicular line  Push down on the skin to create angle of entrance.  Keep open end of needle away from heart on entrance to pericardium

12. Epicardial Access  Lungs: the more posterior you advance the less likely to hit lungs  Diaphram/infradiaphragmatic vessels  Liver: more lateral less risk of injury  LIMA: begin 20-30 degrees then angle deeper after past xiphoid towards cardiac silhouette 40 degrees lao

13. Epicardial access  Air in pericardium: evacuate as cannot cardiovert nor defibrilate.  Aspirate frequently  Ablate: initally 15W irrigation 30 cc temp 40- 41  20-25W average)

15. Sagittal section of a cadaveric specimen. Koruth J S et al. Circ Arrhythm Electrophysiol 2011;4:882- 888 Copyright © American Heart Association

16. Scar Map of VT

17. Epicardial Fat vs Scar  Inferolateral less fat  RV free wall and RVOT more fat.  >3 mm fat cannot burn through  0-5 mm fat voltage can be similar to normal myocardium. >5 mm will have low voltages and no capture at 10ma unipolar pacing.  Endo scar <1.5 mv/ Epi Scar <1 mv with wide split potentials and late potentials

18. Epicardial Access Complications  Hemopericardium/tamponade  Hemoperitoneum  Injury to epicardial vessel (artery or vein)  Phrenic nerve injury  Hepatic injury

20. Early hemopericardium 1. Inadvertent right ventricular (RV) puncture 2. Perforation of an epicardial vessel (artery/vein) 3. Disruption of pre-existent pericardial adhesions

22. Intraoperative image of the surgically repaired laceration (arrow) to a large-caliber posterolateral branch of the coronary sinus. Koruth J S et al. Circ Arrhythm Electrophysiol 2011;4:882- 888 Copyright © American Heart Association

23. A, Location of 2 puncture sites (black arrows) within the left hepatic lobe in an image obtained during laparotomy. Koruth J S et al. Circ Arrhythm Electrophysiol 2011;4:882- 888 Copyright © American Heart Association

24. A, Left anterior oblique view of right coronary angiography. Koruth J S et al. Circ Arrhythm Electrophysiol 2011;4:882- 888 Copyright © American Heart Association

25. Transverse view of an abdominal CT scan with contrast showing a large heterogeneous lesion in the left hepatic lobe (arrows), measuring 6×7×11 cm. Koruth J S et al. Circ Arrhythm Electrophysiol 2011;4:882- 888 Copyright © American Heart Association

26. CT angiography of the anterior aspect of the heart illustrating the course of the great cardiac vein in relation to the left anterior descending coronary artery (LAD) and the left circumflex coronary artery (Cx). Baman T S et al. Circ Arrhythm Electrophysiol 2010;3:274- 279 Copyright © American Heart Association

27. Post ablation  Leave Pigtail in place: delayed tamponade  Pericarditis: triamcinalone 2mg/kg into pericardium  Pain management

28. Summary  Epicardial ablation is feasible for arrthythmias  There are specific techniques and attention to procedural details that are necessary to avoid complications and optimize outcomes  Complications can be avoided and mitigated by a knowledge of the anatomy and the experience of others.

29. Thank you

30. Right ventricular (RV) angiogram reveals contrast entering a crypt (arrow pointing to structure encircled) extending inferiorly below the RV wall. Koruth J S et al. Circ Arrhythm Electrophysiol 2011;4:882- 888 Copyright © American Heart Association

33. Epicardial VT Morphology