A Case of Bundle Branch Re-entrant Ventricular Tachycardia 1 Year After Transcatheter Aortic Valve Replacement.

Bundle branch re-entrant ventricular tachycardia (VT) (BBR-VT) is a unique type of ventricular tachycardia often seen in patients with advanced heart diseases. Rarely, it is found in patients with a structurally normal heart. We describe a case of BBR-VT in a patient with normal ventricular function, a year after transcatheter aortic valve replacement (TAVR) for aortic stenosis. A 73-year-old man with a past medical history of non-obstructive coronary artery disease and severe aortic stenosis status post-TAVR with a 23-mm Sapien valve (Edwards Lifesciences, Irvine, CA, USA) about 1 year prior presented with palpitations and syncope. The electrocardiogram (ECG) showed a wide complex tachycardia with a left bundle branch block (LBBB) pattern and atrioventricular dissociation. The tachycardia was incessant and paroxysmal during 24-h telemetry monitoring. An electrophysiology study showed a normal A-H interval of 90 ms and a prolonged H-V interval of 84 ms with evidence of a split His. A hemodynamically stable VT was induced with a cycle length of 453 ms, which was identical to the clinical VT. This was diagnosed to be BBR-VT given the typical ECG pattern of LBBB, the presence of His inscription before each ventricular signal, and the H-H interval variation-predicted V-V variation when there was a wobble in tachycardia cycle length. Injury of the His-Purkinje system post-TAVR can provide the substrate for the development of BBR-VT. Current published literature shows early occurrence post-TAVR, but our case suggests that the timing between the index procedure and arrhythmia occurrence can be variable.