Prospective study on the occurrence and management of chronic sinoatrial disease, with follow-up.

Sinoatrial disease can cause vague and intermittent symptoms and may be overlooked unless specially searched for. In a prospective study the disorder was found in 5I patients as against 98 with atrioventricular block, i.e. a relative incidence of 34 per cent. Several patients were referred from the neurologist. It is notable that rheumaticfever had occurred in 20 per cent. About 6o per cent hadparoxysmal atrial fibrillation/tachycardia. Follow-up studies were carried out for an average period of 5 years after pacemaker implantation in 23 patients and during medical or no therapy in the remaining 28. Ventricular pacing abolished syncope and was often successful in preventing paroxysmal tachycardia without additional use of drugs. In most patients drug therapy alone was unsatisfactory. However, small doses of digitalis were used with fair success in 6 patients whose main trouble was paroxysmal tachycardia. In 5 others with bradycardia only, long-term oral isoprenaline prevented syncope without side effects.