Two-Dimensional Echocardiographic Evaluation of Right Ventricular Function in Acute Myocardial Infarction

Twenty-five patients with acute myocardial infarction, 15 inferior wall (IWMI) and 10 anterior wall (AWMI), were studied using two-dimensional echocardiography (2DE) and blood pool scan to evaluate the accuracy of 2DE for measuring right ventricular function. Fractional shortening (FS) of the minor axis of the right ventricle in the apical four chamber view (A4C) and subcostal four chamber view (S4C) for AWMI patients was higher as compared to the control group (41.8± 11 vs 27±9 and 46±8 vs 27±7 respectively). FS of the minor right ventricular axis for isolated IWMI subjects in the same views was not significantly different from the control population (32±7% vs 27±9% and 34± 13 vs 27±7% respectively). However, patients with an IWMI complicated by right ventricular infarction (RVI) had a significant depression of FS of the minor axis as compared to the control group in both the A4C and S4C views (8±5% vs 27±9% and 18±7 vs 27±7% respectively). FS of the minor axis in only the A4C view correlated . well with the corresponding blood pool scan ejection fraction (EF) for the entire infarction group (r=.69, p<.001). Long axis FS was not significantly different from controls for the IWMI and AWMI group and the correlation with the blood pool scan EF was poor (r= .32 and r=.09 respectively). Surface area of the right ventricle in the A4C view was increased in four of six patients with RVI and six of six patients with blood pool scans. FS of the minor axis in the A4C view correlated well with right ventricular function and was accurate in identifying those patients with an RVI. FS of the long axis was not a reliable measurement for evaluating right ventricular function. Surface area determination of the right ventricular cavity did not prove to be a sensitive index of right ventricular function in addition.