Use of digitised left ventricular echocardiograms in assessment of mitral stenosis.

In order to establish a new echocardiographic index of the severity of mitral stenosis, left ventricular echocardiograms were digitised using manual tracing and a computer. The instantaneous left ventricular dimension was measured in 15 patients with mitral stenosis. The peak rate of change of left ventricular dimension (peak dD/dt) and the normalised peak rate (peak dD/dt/D) during early diastole were significantly lower in mitral stenosis than in normal subjects. Also, the time between the second heart sound and peak dD/dt was significantly shorter in patients with mitral stenosis than in normal subjects. Correlation between the mitral valve area calculated from the Gorlin formula and peak dD/dt/D was good, while valve area was poorly correlated with the EF slope of the anterior mitral leaflet echo. It is suggested that by continuous measurement of left ventricular dimension and of its first derivative, the reduced atrioventricular blood flow in mitral stenosis can be shown, and that peak dD/dt/D during early diastole is a possible index of its severity.