Electrophysiological aids in congestive heart failure: supporting and synchronizing systole

A variety of electrophysiologic abnormalities is seen in the setting of chronic left ventricular dysfunction. Atrial, atrioventricular, and inter- and intra-ventricular conduction disturbances may place the failing ventricle at a further mechanical disadvantage. Several studies recently have evaluated the safety and efficacy of cardiac resynchronization therapy in moderate to severe heart failure. Data from these studies have shown statistically significant improvements in left ventricular geometry and function, New York Heart Association functional class, exercise tolerance, and quality of life. Some studies have suggested reduction in morbidity and mortality; such findings await confirmation, however, from ongoing largescale outcomes studies.