Long-Term Outcome of Catheter Ablationfor Treatment of Bundle BranchRe-EntrantTachycardia.

Abstract

This study reports the long-term outcome of patients with bundle branch re-entrant tachycardia (BBRT) who underwent catheter ablation for ventricular tachycardia (VT). BBRT is an uncommon mechanism of VT. Data on long-term outcomes of patients with BBRT treated with catheter ablation are insufficient. Between 2005 and 2016, 32 patients had a sustained VT due to a bundle branch re-entrant mechanism. Diagnosis of BBRT was established per standard published criteria. The mode of presentation was syncope in 17 patients (53%) and palpitations in 15 (47%). BBRT was inducible in all subjects, and successful ablation of the right bundle branch in 19 patients (59%) or the left bundle branch in 13 patients (41%) was performed. During follow-up of 95 ± 36 months, 6 patients (19%) died, 3 of progressive heart failure and 3ofnoncardiac causes. Recurrent VT due to BBRT did not occur in any patient. At baseline, 25 patients (78%) had a prolongedHV interval (>55 ms) and 7 (22%) had a normal HV interval (≤55 ms). In patients with a normal HV interval, there was only 1 death (due to malignancy), and no one developed heart block during 90 ± 36 months of follow-up. Ten patients (31%) had normal left ventricular (LV) function (LV ejection fraction≥50%), and 22 (69%) had depressed LV function (LVejection fraction<50%). No deaths were recorded in patients with normal LV function (5 with no implantable cardioverter-defibrillator) compared with 6 deaths among patients with depressed LV function (n= 22; p= 0.07). Radiofrequency ablation of the bundle branch is an effective therapy for treatment of BBRT. Sustained BBRTcanbe seen in patients with normal LV systolic function and HV interval with excellent long-term outcomes afterablation.