Natural History of 'Dysfunction of the Sinoatrial Node

Fifty-two patients with disease of the sinoatrial node were reviewed for the purpose of clarifying the natural history of the sinoatrial nodal dysfunction. Of these, 38 were observed for periods of time ranging from 1 to 23 years (average, six years). All available electrocardiograms of each patient were analyzed. A long duration of the disease was more frequently observed in patients with sinus bradycardia with sinoatrial block or sinus arrest and in patients with persistent atrioventricular junctional rhythm. The duration of the disease in patients with the latter condition with total sinus arrest ranged from 7 to 29 years (average, 13 years). Patients with a normal sinus rate with concomitant sinoatrial block or sinus arrest did not have a different average duration of the disease, as A lthough disease of the sinoatrial node can be a part of widespread disease of the conducting tissue,1’5 the basic events that characterize the sick sinus syndrome are related to disorders of the sinoatrial node or its approaches, or both.#{176}4#{176}