Cross-sectional echocardiographic analysis of the extent of left ventricular asynergy in acute myocardial infarction.

Abstract

Cross-sectional echocardiography was used to study left ventricular wall motion in 44 patients with myocardial infarction, and the extent of observed asynergy was correlated with left ventricular function. Echocardiographic studies were performed in short and long axes of the ventricle and 9 segments were identified for analysis. Wall motion in each segment was classified as normal, hyperkinetic, hypokinetic, akinetic or dyskinetic. Based on this analysis a wall motion index was derived as an overall assessment of left ventricular asynergy. Left ventricular function was measured by clinical and hemodynamic parameters to note the presence of pulmonary congestion or peripheral hypoperfusion or both. Segmental asynergy was detected in all patients with acute myocardial infarction. Patients with uncomplicated infarction had a wall motion index of 3.2 .+-. 2.4, which was significantly less than that in patients with pulmonary congestion (9.7 .+-. 3.1 P < 0.001) or with both pulmonary congestion and hypoperfusion (10.6 .+-. 4.8, P < 0.001). In 9 patients with acute ventricular septal defect or acute mitral regurgitation, wall motion index was 6.7 .+-. 1.9, significantly less than with other complicated infarcts (P < 0.001) but greater than with uncomplicated infarcts (P < 0.005). Wall motion index also discriminated complicated from uncomplicated infarction when death was used as the end point. Cross-sectional echocardiography provides a method of measuring the extent of left ventricular asynergy during acute myocardial infarction that correlates well with hemodynamic parameters of left ventricular function.