Delayed efficacy of radiofrequency catheter ablation on ventricular arrhythmias originating from the left ventricular anterobasal wall.

BACKGROUND: Ventricular arrhythmias (VAs) originating from the left ventricular anterobasal wall (LV-ABW) may represent a therapeutic challenge.

OBJECTIVE: The purpose of this study was to investigate the delayed efficacy of radiofrequency catheter (RFCA) ablation without an epicardial approach on VAs originating from the LV-ABW.

METHODS: Eighty patients (mean age 46.9 ± 14.9 years; 47 male) with VAs originating from the LV-ABW were enrolled. After systematic mapping of the right ventricular outflow tract, aortic root, adjacent LV endocardium, and coronary venous system, 3-4 ablation attempts were made at the earliest activation sites and/or best pace-mapping sites. Delayed efficacy was evaluated in patients with acute failure.

RESULTS: During mean follow-up of 23.8 ± 21.9 months (range 3-72 months), complete elimination of all VAs was achieved in 47 patients (59%) and partial success in 19 (24%), for an overall success rate of 83%. In 25 of 37 patients (68%) with acute failure, VAs were eliminated or significantly reduced (>80% VA burden) by the delayed effect of RFCA during follow-up. Logistic regression analysis revealed that response time to ablation was a predictor of occurrence of delayed efficacy. No complications occurred during follow-up.

CONCLUSION: Instead of extensive ablation, waiting for delayed efficacy of RFCA may be a reasonable choice for patients with VAs arising from the LV-ABW.