His-Bundle Pacing and LV Endocardial Pacing as Alternatives to Traditional Cardiac Resynchronization Therapy.

Abstract

Cardiac resynchronization therapy (CRT) using biventricular pacing (BVP) is the cornerstone of treatment for patients with heart failure and left bundle branch block. Up to a third of patients do not respond to BVP. This article reviews the utility of His-bundle pacing (HBP) and Left ventricular (LV) endocardial pacing as alternatives to BVP to provide ventricular synchrony. HBP has shown promising results in observational studies. By significantly narrowing or normalizing QRS, HBP has improved clinical outcomes including ejection fractions both as a rescue option in patients who failed BVP or as a primary alternative. LV endocardial pacing has also shown promise with improved clinical outcomes. Using traditional pacing leads or novel technology, direct stimulation of the LV endocardium allows for better site selection as well as a more physiological activation of the LV compared to traditional epicardial LV stimulation. HBP and LV endocardial pacing are valuable alternatives to traditional BVP to achieve CRT. Randomized clinical trials in progress will allow for a deeper understanding of how they can benefit our patients.