[Total and segmental left ventricular ejection fraction of acute myocardial infarct patients during serial...

Ultrasonic scanning of the heart was carried out on days 1, 10, 20 and 30 of uncomplicated myocardial infarction (MI) in 46 patients whose total and segmental ejection fraction (EF) (5 segments by a two-chamber projection from the apex) were then calculated. Total left-ventricular EF was moderately reduced on day 1 (48.6 +/- 1.8%) and increased significantly by day 30 (55.4 +/- 2.3%, p less than 0.01). All patients showed impaired segmental contractility in infarcted areas. Segmental EF was essentially reduced in segments 3, 4 and 5 in anterior MI, and in segments 1 and 2 in posterior MI. Recovery was associated with increasing EF in asynergic segments, that nevertheless remained diminished on day 30, as compared to unaffected areas. The rise in left-ventricular total EF is attributed to better contractility of asynergic segments.