Biventricular pacing in paced patients with normal hearts.

Right ventricular apical (RVA) stimulation, although beneficial in the treatment of symptomatic bradycardia, has proven detrimental in a substantial percentage of pacemaker recipients, leading to iatrogenic deterioration of left ventricular structure and function. Alternative right ventricular pacing sites appeared advantageous but their superiority has not been proven. Biventricular stimulation is effective in reducing ventricular dyssynchrony in subgroups of heart failure patients, improving their functional capacity, morbidity, and mortality. Therefore, it seems logical that this pacing strategy, by eliminating ventricular dyssynchrony, could play an important role in preventing the deleterious effects of chronic RVA stimulation in patients with normal hearts who undergo cardiac pacing for bradycardia indications. Preliminary investigations have yielded encouraging results, but further studies with harder endpoints such as quality of life, morbidity, and mortality are necessary to clarify the potentially advantageous effect of biventricular stimulation in paced patients with normal hearts.