Biventricular pacing in patients with heart failure and intraventricular conduction delay

In patients with advanced chronic heart failure, characterized by prolonged QRS duration and by decreased cardiac contractility, decreasing dysynchrony by biventricular pacing seems to improve exercise tolerance (6-min walk distance), symptoms (New York Health Association class), and quality of-life scores. Although the results of several reports were consistent, the numbers of patients studied were small, and many of the changes were trends that did not reach statistical significance. The availability of a non-pharmacological treatment that improves exercise capacity and quality-of-life would be a major advance. However, further studies will need to address the question of mortality and morbidity benefits of such intervention.