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.
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
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
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 degrees then angle deeper after past xiphoid towards cardiac silhouette 40 degrees lao
Epicardial access Air in pericardium: evacuate as cannot cardiovert nor defibrilate. Aspirate frequently Ablate: initally 15W irrigation 30 cc temp 20-25W average)
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
Post ablation Leave Pigtail in place: delayed tamponade Pericarditis: triamcinalone 2mg/kg into pericardium Pain management
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.