His Bundle Electrogram in Patients with Acute Myocardial Infarction

Thirty‐seven patients with acute myocardial infarction complicated by atripventricular or bundle branch block, or a combingtioh of both, had His bundle electrogram studies performed during their stay in the coronary care unit. The acute mortality of the 14 patients with a complicating bundle branch block was 50%. Pump failure was the main cause of death. Three patients in this group had a prolonged H‐V interval and one patient had a split bundle of His. The presence or absence of a prolonged H‐V interval did not affect mortality in this group of patients. The acute mortality of the 16 patients with an inferior wall myocardial infarction was 6% The H‐V interval was normal in all but one of these patients. The atrioventricular block was caused by a proximal block in all cases. The acute mortality of the seven patients with an anterior wall myocardial infarction was 29%. The H‐V interval was prolonged in two of seven patients. Pump failure was the acute cause of the deaths. The presence or absence of a prolonged H‐V interval did not affect mortality in this group of patients.