II. Electrocardiographic Changes

¹ Department of Medicine, Karolinska Institutet at Serafimerlasarettet, Stockholm, Sweden

The possibility of surgical intervention in cardiac rupture with tamponade prompted a study of the value of the continuous electrocardiogram (ECG) for an immediate diagnosis. The ECG was recorded continuously in a coronary care unit (CCU) during a time period when 32 deaths occurred. At autopsy seven patients had myocardial rupture with tamponade and their ECGs all showed sudden bradycardia terminally. Another patient had tamponade from dissecting aortic aneurysm and also showed similar ECG changes. Two further patients showed nonpenetrating lacerations of the myocardium, and their ECG did not show sudden bradycardia. In all cases the bradycardia was of nodal origin within the first minutes. It is concluded that abrupt onset of bradyarrhythmias in patients with acute myocardial infarction showing sudden unconsciousness should give rise to a suspicion of cardiac tamponade.