sick sinus syndrome (SSS) [AS, seoc + L, sinus, hollow] , a complex of arrhythmias associated with sinus node dysfunction. The condition may result from a variety of cardiac diseases, ranging from cardiomyopathies to inflammatory myocardial disease. It is most commonly related to either intermittent sinoatrial (SA) block or inadequate SA conduction. SSS is characterized by severe sinus bradycardia, either alone, alternating with tachycardia, or accompanied by atrioventricular block. The most common symptoms are lethargy, weakness, light-headedness, dizziness, and syncope. The severity of symptoms is related to the duration of the asystolic period. Elderly patients with episodes of near-syncope associated with a history of palpitations are most likely to be symptomatic. Accurate diagnosis requires electrocardiography. At present the only treatment is the implantation of a permanent pacemaker.
