The sick sinus syndrome in atrial disease

Although little basic information exists regarding atrial disease, certain clinical states can be grouped into a syndrome resulting from a failing sinoatrial (SA) node. One or more of the following symptoms appears: persistent, severe, and unexpected sinus bradycardia; cessation of sinus rhythm for short intervals with other rhythms supervening; long periods of sinus arrest without rescue rhythm, which produces cardiac arrest; untreated chronic atrial fibrillation with slow ventricular rate; no sinus rhythm after cardioversion; SA exit block. Symptoms spring from hypoperfusion of vital organs.