Measurement of instantaneous left ventricular dimension and filling rate in man, using echocardiography.

A technique has been devisedfor deriving instantaneous measures of left ventricular dimension and its rate of change from a standard echocardiogram of the left ventricular cavity. Using the cube of the dimension as a measure of left ventricular volume, estimates offilling rates were also made. The characteristics of left ventric- ular filling were studied in IO normal subjects, and in 5o patients with different types of heart disease. In normal subjects, the peak rate of increase of left ventricular dimension had a mean value of iI cm/sec, corresponding to a filling rate of 880 ml/sec. In the presence of mitral regurgitation due to ruptured chordae tendineae, the peak rate of increase of left ventricular dimension and volume was greatly increased to 22 cm/sec and 2400 ml/sec, respectively, while rheumatic mitral stenosis caused a conspicuous reduction in both (mean 6 9 cm/sec and 2I0 ml/sec). Aortic regurgitation was associated with an increased peak leftfilling rate of I6oo mllsec, though the rate of change of left ventricular dimension was within normal limits, while left ventricular disease did not appear to be associated with any consistent abnormality. In all groups of patients, except those with rheumatic mitral stenosis, the filling pattern consisted of an initial period of accel- erating outward wall movement lasting O-i to o0I3 sec, followed by progressive reduction in velocity until the onset of atrial systole. This pattern appeared to reflect a discontinuity in the factors governing ventricular filling whose cause was not apparent from the present study.