Chronic Symptomatic Sinoatrial Block: A Review of 34 Patients and Their Treatment

¹ Cardiovascular Research Unit, Department of Medicine, University of the Witwatersrand, and the Cardiac Clinic, General Hospital, Johannesburg

Thirty-four patients (mean age 64 years) with this syndrome are reviewed. Common symptoms relate to transient cerebral ischemia with syncope, episodes of rapid palpitations, or both. Usually no definite etiology was found but ischemic heart disease was present in 12 of the 34. Thirty patients had objective evidence of other cardiac disease besides, the sinoatrial block. Additional conduction disturbances were present in 14 subjects. Calcification was found in the mitral or aortic annulus in nine cases. It is likely that sinoatrial block is only symptomatic and important if other processes are present which may decrease the automaticity of lower pacemaker areas. This may take the form of associated cardiac disease or excessive vagal tone as in three cases of reversible chronic sinoatrial block with peptic ulcer. Treatment with drugs alone is almost always unsuccessful. Long-term cardiac pacing either alone or in combination with drugs usually alleviates the major symptoms.