Computerized echocardiographic analysis to detect abnormal systolic and diastolic left ventricular function in children with aortic stenosis

Abstract

Experience with computer analysis of M mode echocardiograms for the evaluation of left ventricular function in patients with left ventricular pressure overload is reported. In order to study systolic and diastolic left ventricular function, endocardial surfaces of the septum and posterior wall were digitized and analyzed by minicomputer. The subjects included 52 normal children and 30 children with catheterization-proved aortic stenosis with (13) and without (17) coarctation. Compared with the normal children, the patients with aortic stenosis had a statistically smaller and thicker walled left ventricle and increased fractional shortening of the left ventricular minor axis. Continuous tracings of minor axis dimension and the first derivative of these tracings were plotted. The tracings allowed measurement of the maximal velocity of shortening and lengthening. Maximal velocity of shortening (normal = 96.8 ± 3 mm/sec [mean ± standard error of the mean]) was depressed to 80.8 ± 4.7 mm/sec) in the group with pressure overload. Maximal velocity of lengthening (normal = 116.4 ± 3 mm/sec) was also depressed (88.4 ± 5.2 mm/sec) in this group. Although the velocity measurements allowed separation of the normal from the abnormal group, they did not correlate closely with either left ventricular wall thickness or left ventricular systolic pressure and therefore they cannot be used to assess the severity of the left ventricular pressure overload or the need for surgical correction. Nonetheless, the study provides a method for analyzing left ventricular diastolic and systolic dynamic function from a ventricular M mode echo alone and suggests abnormal systolic and diastolic left ventricular performance in some children with aortic stenosis and left ventricular hypertrophy.