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Updated: Jun 12, 2026

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
His bundle extrasystoles revisited: the great electrocardiographic masquerader
Abdul Ameen1, Amita Dharawat, Abdullah Khan
1New York Harbor VA Healthcare Center, State University of New York Downstate Medical Center, Brooklyn, NY 11209, USA.
Abstract:
A 74-year-old man with past history of near syncope presented with frequent periods of second-degree atrioventricular block (2° AVB). An electrophysiological study revealed prolonged atrial-His and His-ventricular (HV) intervals and frequent His bundle (H) extrasystoles. The latter manifested in the surface electrocardiogram as premature atrial, junctional, or ventricular beats, as well as 2° AVB that mimicked Wenckebach or Mobitz II block. Procainamide markedly suppressed H extrasystole. However, because of the presence of prolonged HV interval and history of presyncope, a permanent pacemaker was inserted. The case illustrates the varied manifestation of H extrasystole and presents guidelines for management.
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