Arrhythmias Associated With Sinus Node Dysfunction

Abstract

DURING the past 15 years, we have become increasingly aware of the importance of arrhythmias associated with sinus node dysfunction as a cause of cardiac and neurological symptoms. These arrhythmias currently afflict more than 100,000 Americans, and as a group constitute the most common indication for permanent cardiac pacemaker implantation. The objectives of this review are (1) to discuss the pathogenesis and pathophysiology of arrhythmias associated with sinus node dysfunction, (2) to provide a clinical, electrocardiographic, and electrophysiological basis for their diagnosis, and (3) to discuss principles of management, including the use of the cardiac electrophysiology laboratory. Anatomy and Pathophysiology The sinus node is located in the posterior right atrial wall at the junction of the right atrium and superior vena cava. 1 It consists of three types of cells: P cells, transitional cells, and Purkinje's cells. 2,3 The P cells, which are located in the midst of a collagen