Assessment of left ventricular function during angina pectoris from the mitral valve echogram.
The echocardiographic motion pattern of the anterior mitral valve (aMV) has been shown to be related to left ventricular function. In an attempt to quantify the changes of aMV motion in patients during myocardial ischemia, the following motion phases of the aMV echo were determined in 12 patients with coronary artery disease: DE slope, EF slope, the closure slope of the aMV, as determined by joining points B and C (or in the absence of a clearly definable B point the AC slope), and the systolic motion pattern. Following coronary angiography, measurements of the aMV echo were performed in the resting state and during angina pectoris immediately after rapid atrial pacing at comparable heart rates. DE slope and EF slope showed only minor and insignificant changes during angina in the post-pacing period. The aMV closing velocity (BC or AC slope) was significantly reduced from 225.9 +/- 56 mm/sec during the control period to 177.9 +/- 43 mm/sec during angina (p < 0.01). After recovery from anginal pain measurements of the final closing velocity revealed a return to the control values with an average slope of 240.4 +/- 40 mm/sec. In 3 of 12 patients there was evidence of systolic mitral valve prolapse during the post-pacing anginal episode. Our results suggest that final mitral valve closing velocity reflects changes in left ventricular function during myocardial ischemia in the early isovolumetric phase of ventricular systole. In some patients mitral valve prolapse during angina may indicate ischemic dysfunction of the papillary muscles during the ejection of phase of systole.