Reliability of Vectorcardiography in Assessing the Severity of Congenital Aortic Stenosis

CONGENITAL AORTIC STENOSIS is a potentially serious heart defect which may require surgical correction even in asymp- tomatic children. The assessment of its severi- ty consists of two steps: the clinical evaluation and cardiac catheterization. The latter may represent a major surgical procedure. Many investigators have been tempted to use clinical criteria and simpler laboratory procedures, particularly electrocardiography, to select pa- tients for physiological studies. In spite of the fact that some relationships have been demonstrated between the various simple clinical tests and the severity of aortic stenosis, accurate assessment of the severity has not been possible without cardiac catheterization. Recently, it has been suggested that certain vectorcardiographic measurements permit a reasonable assessment of the severity of aortic stenosis.1' 2 The purpose of this communication is to report the findings of a study designed to test the accuracy of this method in assessing the severity of congenital valvular aortic stenosis. Methods This study consisted of relating vectorcardio- grams and hemodynamic data from 28 patients with congenital valvular aortic stenosis and from 23 normal persons. Frank-lead system vectorcar- diograms were taken with the patients resting in a supine position. The A, C, E, I and M electrodes were placed in the fourth intercostal space. Alternate loops of the planar forms of the vector- cardiograms were displayed on a vectorcardiograph* (PV-3) and the loops photographed with