Left posterior fascicular branch block could not predict the success of ablation for left posterior fascicular ventricular tachycardia

Abstract

Objective Until now, whether left posterior fascicular block (LPFB) could predict the success of ablation for fascicular ventricular tachycardia (VT) is ongoing controversy.In this study, we investigated whether LPFB could be as the predictor of left posterior fascicle VT(LPF-VT) long term success after ablation. Methods From January 2010 to December 2012, consecutive patients (n=67) with LPF-VT underwent mapping and ablation by using three dimension mapping and ablation were enrolled in department of cardiology the First Affiliated Hospital of Nanjing Medical University.Burst and programmed stimulation at the right atrium and right ventricle apex were used for VT inducing.Activation mapping was performed to find the ablation target (earliest fascicular potential, PP) during VT.Pace mapping was used to locate the ablation target for patients in whom VT could not be induced.Ablation was performed by delivering radiofrequency energy in temperature-control mode.According to LPFB or not, patients were assigned to LPFB group (group A) and LPF not block group (group B), and with long-term follow-up. Results Among 67 patients (mean age 30.1±12.6, male 53) with LPF-VT, VT could not be induced in two cases, failed ablation in one case.Ablation target with earliest P potential was located by activation mapping during VT in 61 patients.Ablation target was disclosed by pace mapping in 3 patients.Altogether, ablation was succeeding in 64 cases without inducing of VT with isoproterenol infusion.After ablation, 46 patients were enrolled in group A, and 18 were in group B. During (55.8±10.4)months of follow-up, the long term success rate after a single procedure without anti-arrhythmic agents was 82.8%(53/64). VT reoccurred in 11 cases, 8 cases in group A, 3 cases in group B(P=0.94). The mean duration of reoccurred time was 1.4-54.9(9.2±16.1) months after the ablation.All reoccurred 11 cases and one failed case had repeated successful ablation.No complications were observed in these cases. Conclusions Activation mapping guided ablation is highly effective and associated with long term clinical outcomes in patients with LPF-VT.The reoccurred rate was not lower in LPFB group, indicating that LPFB could not predict long term success of ablation for LPF-VT. Key words: Fascicular ventricular tachycardia; Activation mapping; Left posterior fascicle block