Permanent His Bundle Pacing: The Past, Present, and Future.

Long-term right ventricular (RV) apical pacing has been associated with an increased risk of death, heart failure, and atrial fibrillation (AF). Alternative sites for RV pacing have not proven to be superior to RV apical pacing. Cardiac resynchronization therapy (CRT) using a biventricular (BiV) lead system is indicated for patients with a low left ventricular ejection fraction and QRS prolongation, but there remains about a 25-30% nonresponse rate. CRT has been less effective for nonleft bundle branch block conduction delay and with normal/low normal left ventricular function. Over the past decade, there have been more data on the feasibility and advantages of pacing at the His Bundle (HB) region. We review the anatomy and physiology of the HB, the available data on permanent HB pacing, its current and potential future applications.