There is increasing evidence that significant primary alterations of cardiac electrophysiologic properties occur with the normal aging process. The age-related changes in cardiac electrophysiologic parameters are seen as alterations in the surface electrocardiogram, depressed sinus and atrioventricular nodal function, and increased refractoriness of the cardiac tissue. The mechanisms underlying these changes may consist of structural changes of the conduction system, autonomic nervous system dysfunction, or changes in cellular electrophysiology. As a result of these changes, the responsiveness of the aging heart to cardiotropic drugs is different from that of the younger heart. Elderly subjects are prone to certain electrophysiologic syndromes that merit special consideration
