Cineangiographic assessment of left ventricular function in the acute phase of transmural myocardial infarction

Abstract

One hundred fifteen patients underwent hemodynamic investigation including left cineangiography during the acute phase of transmural myocardial infarction. Patients were classified into two groups: those with anterior myocardial infarction (48 patients) and those with inferior myocardial infarction (67 patients). There was a good correlation between the electrocardiographic site of infarction and the location of ventricular dyssynergy. The extent of abnormally contracting segment was 39.3 ± 2 percent (mean ± standard error of the mean) in anterior infarction and 28 ± 1.7 percent in inferior infarction. Left ventricular end-diastolic volume was normal in inferior infarction and slightly increased in anterior infarction. Left ventricular end-diastolic pressure was significantly increased in both groups. The increase in left ventricular end-diastolic pressure was related to (1) depressed contractility as demonstrated by the significant reduction of ejection fraction and mean velocity of circumferential fiber shortening; and (2) changes in left ventricular compliance with a large scatter to the left as well as to the right of the pressure-volume curve. There was no correlation between the extent of dyssynergy and changes in left ventricular end-diastolic compliance but there was a good linear correlation between ejection fraction and the extent of abnormally contracting segment. In the group with anterior infarction, for the same extent of dyssynergy, patients with a decreased end-diastolic compliance had a better ejection fraction than those with an increased end-diastolic compliance. Finally, the extent of infarction seems to be the principal factor determining the degree of ventricular functional impairment because patients with anterior or inferior myocardial infarction carefully matched for similar extent of infarction demonstrated no significant differences in the variables of ventricular performance.