Feasibility and safety of catheter ablation of electrical storm in ischemic dilated cardiomyopathy.

Aims: Electrical storm is an emergency in 'implantation of a cardioverter defibrillator' carriers with ischemic dilated cardiomyopathy (DCM) and negatively impacts long-term prognosis. We evaluated the feasibility, safety, and effectiveness of radiofrequency catheter ablation (RFCA) in controlling electrical storm and its impact on survival and ventricular tachycardia/fibrillation recurrence.

Methods: We enrolled 27 consecutive patients (25 men, age 73.1 ± 6.5 years) with ischemic DCM and an indication to RFCA for drug-refractory electrical storm. The immediate outcome was defined as failure or success, depending on whether the patient's clinical ventricular tachycardia could still be induced after RFCA; electrical storm resolution was defined as no sustained ventricular tachycardia/ventricular fibrillation in the next 7 days.

Results: Of the 27 patients, 1 died before RFCA; in the remaining 26 patients, a total of 33 RFCAs were performed. In all 26 patients, RFCA was successful, although in 6/26 patients (23.1%), repeated procedures were needed, including epicardial ablation in 3/26 (11.5%). In 23/26 patients (88.5%), electrical storm resolution was achieved. At a follow-up of 16.7 ± 8.1 months, 5/26 patients (19.2%) had died (3 nonsudden cardiac deaths, 2 noncardiac deaths) and 10/26 patients (38.5%) had ventricular tachycardia recurrence; none had electrical storm recurrence. A worse long-term outcome was associated with lower glomerular filtration rate, wider baseline QRS, and presence of atrial fibrillation before electrical storm onset.

Conclusion: In patients with ischemic DCM, RFCA is well tolerated, feasible and effective in the acute management of drug-refractory electrical storm. It is associated with a high rate of absence of sustained ventricular tachycardia episodes over the subsequent 7 days. After successful ablation, long-term outcome was mainly predicted by baseline clinical variables.