His-Bundle Pacing: A Novel Treatment for Left Bundle Branch Block Cardiomyopathy

Abstract

Background LBBB Cardiomyopathy is a reversible cardiomyopathy resulting from chronic left ventricular dysynchrony from left bundle branch block (LBBB). His-bundle pacing (HBP), as opposed to pure mechanical correction, alters the underlying substrate for dysynchrony, providing a physiologic instead of mechanical treatment of LBBB. Objective To assess the feasibility of HBP for cardiac resynchronization therapy (CRT) in LBBB Cardiomyopathy patients Methods Retrospective chart review was conducted on patients who underwent cardiac resynchronization therapy at Indiana University Health and Ezkenazi Hospital between August 1, 2015 to August 30, 2017. A subset of patients who met the pre-defined syndrome criteria of LBBB cardiomyopathy: 1) History of pre-existing LBBB of at least 6 months or greater 2) LVEF of > 50% at the time of diagnosis of LBBB 3) Progressive decrease in LVEF to ≤ 40% with development of NYHA functional class II to IV symptoms 4) No other identifiable cause of cardiomyopathy who underwent HBP were identified. Clinical, echocardiographic, and electrophysiologic variables were extracted at baseline and follow-up. Comparison of the means at baseline and follow up was performed using 2-tailed t testing. A p value Results From August 2015 to August 2017, 73 patients underwent CRT. 9 patients (12%) met criteria for LBBB Cardiomyopathy with 7 of those patients (78%) successfully undergoing HBP-CRT. Average time from device implantation to last follow-up was 14.5 months. Mean LVEF improved from 25 ± 6% to 50 ± 4% (p Conclusions Improvement of left ventricular function with HBP indicates that LBBB-induced cardiomyopathy is reversible and can be treated with physiological pacing. His-bundle pacing is a viable technique for pursuing cardiac resynchronization therapy in patients with LBBB Cardiomyopathy.