The Electrophysiological Characteristic And Ablation Strategies Of Bundle Branch Reentry Ventricular Tachycardia In Patients Without Structural Heart Disease

Objective To elucidate the electrophysiological characteristic and ablation strategies of such normal structural heart patients with bundle branch reentry ventricular tachycardia(BBR-VT).Methods and Results Nineinducible BBR-VT patients withoutovert structural heart disease were enrolled in this study.The mean cycle length during tachycardia was 329.3±89.1ms,the mean HV interval during tachycardia was 85.9±17.5ms,which was longer than the baseline(P=0.042).Right bundle(RB)potential was recorded in five patients.The H-RB interval was shorter or similar compared withbaseline(33.8±22.8ms vs.49.4±10.3ms,P=0.12);however,the comparisons of RB-V interval was significantly different during tachycardia and baseline(55.0±34.1ms vs.29.6±23.5ms,P=0.029).There was no significant difference of HV interval before and after ablation(76.8±16.3ms vs.79.3±16.4ms;P=0.17).After a mean follow-up of 31.4 ± 25.7 months,seven patients remained free from VT,bundle branch block still was present the surface ECG in all 9 patients.One patient occurred premature ventricular contraction;one patient with LBBB pattern had cardiac resynchronization therapy(CRT).One patient was implanted cardiac defibrillator(ICD)because of new VT occurrence.The remaining patients with the criteria of device implantation refused to implant pacemaker.Conclusions BBRT can be induced in patients without structural heart disease.Different ablationstrategies used due to the ORS morphology of normal sinus rhythm.These patients need intensive follow-up after successful ablation.