[Hemodynamic significance of the A/E ratio and B-B' step formation on the mitral valve echogram in patients with myocardial infarction].

We evaluated the hemodynamic significance of a B-B' step (shoulder) formation and the A/E ratio of the mitral valve echogram in 31 cases with myocardial infarction. Left ventricular (LV) motion and pressures were analyzed by cardiac catheterization, and were compared with the value of the A/E ratio and the presence or absence of the B-B' step. The B-B' step with its ratio to A wave of 0.5 or more in height was regarded as abnormal: 1) A LV pressure increase by atrial contraction was greater than 10 mmHg in 10 cases with abnormal B-B' step, whereas it was smaller than 9 mmHg in 14 cases without the abnormal B-B' step. 2) While the abnormal B-B' step was recognized in all seven cases who showed akinesis of the LV wall motion in both the anterior and apical portions, it was not seen in 12 of 13 cases who showed hypokinesis in both areas. The B-B' step was also seen in four of six cases who showed diffuse hypokinesis (more than 3 areas of LV wall segments by definition of the American Heart Association). 3) The B-B' step was not seen in any cases with the A/E ratio greater than 0.85 and all these cases had hypokinetic areas less than two segments. In contrast, the B-B' step was recognized in five of six cases with the A/E ratio smaller than 0.7. They had extensive hypokinetic areas more than three segments. We conclude that a B-B' step and the A/E ratio of the mitral valve echogram would be valuable indicators suggesting decreased left ventricular diastolic compliance and is useful in predicting the severity and extent of myocardial asynergy in cases with myocardial infarction.