Transient atrioventricular standstill. Etiology and management.

Four patients with different clinical conditions had transient cardiac standstill for periods of up to 22.5 seconds. All patients showed signs of cerebral ischemia and required cardiac resuscitation. In one patient, the standstill was thought to be the result of a transient increase in the vagal tone, and no long-term therapy was required. In the second patient, cardiac standstill occurred during hospitalization for impending myocardial infarction. Coronary arteriography followed by coronary artery surgery was performed, and there was no further episodes of standstill. In the third patient, standstill was probably related to long-term ingestion of propranolol hydrochloride, and was not observed after this medication was discontinued. In the fourth patient, standstill was the result of the sick sinus syndrome, and a permanent pacemaker was inserted. Standstill of both atria and ventricles may occur under different clinical settings, and management of arrhythmia should be guided by thf etiology of the arrhythmia.