Abstract 646: Epicardial Ablation Of Ventricular Tachycardia - A Single Centre Experience

Background: Radiofrequency current ablation (RFA) of ventricular tachycardia (VT) focuses on endocardial (endo) substrates. However, if endo RFA fails, an epi approach is a potential treatment option. We report a single centre experience of epi VT ablation. Patients and Methods: Between 06/2005 and 02/2008 42 pts (14 female, mean age 49 ± 18 years) underwent electroanatomical endo and epi mapping and ablation for intractable VT, syncope or VT storm with multiple ICD discharges. Pts with normal heart (n=7), ischemic cardiomyopathy (ICM; n=8), NICM (n=11), ARVD (n=8), LV-aneurysm (n=7) or sarcoidosis (n=1) were studied. Mean LV ejection fraction was 45±12%. 20/42 had had at least 1 previous ablation attempt for VT (range 1– 4 ablations). Acute success was defined as non-inducibility of the previously inducible VT. Chronic success was defined as recurrence of any VT. Results: Acute procedural success rate was 79% (30/38). In 4 pts VTs were not inducible during EPS. In 28/42 pts endo mapping revealed no pathologic potentials. In 23/38 pts and 7/38 the succesful RFC ablation site was epi and endo, respectively. In 9/38 pts endo ablation failed and VT could only be ablated from epi. Further 7/38 pts needed both endo and epi ablation. In In 4/8 failed ablations epi RFC ablation was impossible due to failed access to target site (adhesions; n=2), close vicinity of a coronary artery (n=1) or the phrenic nerve (n=1). Procedure duration was 263±97 min. Unfortunately, 1 pt died due to perforation of RV and 1 pt had severe hepatic bleeding after epi puncture. One pt died in cardiogenic shock 1 d after the procedure. In 2 pts a sterile pericarditis occurred which resolved without any further intervention. After a median follow-up of 293 days (1–929 days) 53% of pts were alive and free from any VT. Conclusion: In pts with failed endo RFC ablation for VT due to different etiologies epi RFC ablation was acutely successful in 61% of pts with a moderate chronic success rate. However, major complications occured in approximately 5% of pts. Epi mapping should be considered if endo pathologic potentials are absent or if endo ablation failed.