Sinus node dysfunction in acute myocardial infarction.

. In a retrospective study of patients admitted for acute myocardial infarction (AMI) during six years, sinus node dysfunction (SND) was detected in 29 (1.04%). Twelve had persistent sinus bradycar-dia, 11 sinotrial block or sinus arrest and six brady-tachy syndrome. Symptoms occurred in 17 patients, 12 of whom required temporary pacing for periods up to three weeks. A permanent cardiac pacemaker was implanted in three patients with brady-tachy syndrome. Three patients died during the primary admission and six during the observation period. Follow-up after a mean observation period of 34 months showed continuous signs of SND in 11 out of 19 patients. The arrhythmia caused symptoms in five patients, two of whom had a cardiac pacemaker and two received medical treatment. It is concluded that SND appearing during an AMI persists in a high number of these patients.