Drug-Refractory Ventricular Tachycardias Following Myocarditis: Endocardial and Epicardial Radiofrequency Catheter Ablation

BACKGROUND: -Ventricular tachycardia (VT) is a significant therapeutic challenge in patients with myocarditis. This study aimed to assess the efficacy and safety of radiofrequency catheter ablation (RFCA) of VT in pts with myocarditis. METHODS AND RESULTS: -We enrolled 20 patients (15 males, age 42 [28-52] years) with a history of biopsy-proven viral myocarditis and drug-refractory VT; 5 patients presented with electrical storm. The median left ventricular ejection fraction was 55 (45-60)%. All patients underwent endocardial RFCA with an irrigated catheter, using contact electroanatomical mapping. Recurrence of sustained VT after endocardial RFCA was treated with additional epicardial RFCA. Endocardial RFCA was acutely successful in 14 patients (70%), while in the remaining 6 (30%) clinical VT was successfully ablated by epicardial RFCA. In one patient, hemodynamic instability required an intraaortic balloon pump to complete RFCA. No major complication occurred during or after RFCAs. Over a median follow-up time of 28 (11-48) months, 18 patients (90%) remained free of sustained VT; two patients (10%, both with baseline LVEF ≤ 35%) died of acute heart failure unrelated to ventricular arrhythmias. CONCLUSIONS: -In patients with myocarditis, RFCA of drug-refractory VT is feasible, safe and effective. Epicardial RFCA should be considered as an important therapeutic option to increase success rate.