Atrioventricular Optimized Direct His Bundle Pacing Improves Acute Hemodynamic Function in Patients With Heart Failure and PR Interval Prolongation Without Left Bundle Branch Block

AV-optimized pacing improves acute hemodynamic function in patients with heart failure and long PR interval without left bundle branch block. That it can be achieved by single-site His pacing shows that its mechanism is AV shortening. The improvement is ∼60% of the effect size previously reported for biventricular pacing in left bundle branch block. Randomized, blinded trials are warranted to test for long-term beneficial effects.