Biventricular Pacing in Patients with Bradycardia and Normal Ejection Fraction

In this comparative-effectiveness trial, biventricular pacing prevented the reduction in left ventricular ejection fraction that is seen with right ventricular pacing. The deleterious effect of nonphysiologic right ventricular apical pacing on left ventricular systolic function has been recognized since the 1920s. 1 In the Dual Chamber and VVI Implantable Defibrillator (DAVID) trial, the unexpected increased rates of death and hospital admission for heart failure among patients who were randomly assigned to the dual-chamber, rate-adaptive (DDDR) mode were purportedly due to the adverse effect of right ventricular apical pacing on left ventricular structural remodeling. 2 Results of subsequent trials have supported the notion that right ventricular apical pacing might lead to adverse clinical outcomes in patients with standard pacing indications. 3 – 7 Nevertheless, right ventricular . . .