Reduction in the Rate of Diastolic Descent of the Mitral Valve Echogram in Patients with Altered Left Ventricular Diastolic Pressure-Volume Relations

Abstract

Echocardiographic measurements of the rate of descent of the E wave of the anterior leaflet of the mitral valve during diastole (the mitral valve slope) have been said to correlate with the rate of early left ventricular (LV) filling. Thus, a reduced mitral valve slope in the absence of mitral valve obstruction might be related to impaired LV filling secondary to decreased diastolic compliance. In this study mitral valve slope was compared to several estimates of LV compliance and to the LV end diastolic pressure (EDP) in 32 patients undergoing diagnostic cardiac catheterization: nine normal, 11 coronary artery disease (CAD), seven congestive cardiomyopathy (CC), five left ventricular hypertrophy (LVH). Assuming an exponential relation between pressure (P) and volume (V) at end diastole, and a fixed P intercept at zero V, the following estimates of LV compliance were calculated: (1) the slope of the ln P-V relation (k), which indicates whether a P-V curve is shifted to the left or to the right of normal, (2) an end diastolic distensibility index, (dV/dP) ed, and (3) end diastolic compliance, (dV/VdP) ed. In every instance of mitral valve slope less than 60 mm/sec an abnormality of the LV P-V relation was found. Of the ten patients with a reduced MVS, four had CAD, one had CC and five had LVH. Correlation was good when mitral valve slope was related to k ( r = –0.72, P < 0.001) and to the end diastolic distensibility index ( r = 0.59, P < 0.001); but poor ( P = NS) when compared to end diastolic compliance or to LVEDP. Thus a reduced mitral valve slope, in the absence of mitral valve obstruction, suggests an alteration in the diastolic properties of the left ventricle.