Recognition of Anterior Wall Infarction in Patients with Left Ventricular Hypertrophy

Horizontal plane projections of vectorcardiograms registered by the Frank lead system were analyzed in 36 patients with left ventricular hypertrophy and in 24 with left ventricular hypertrophy and associated anterior wall infarction. All were studied at autopsy. The 0.01-, 0.02-, 0.03-second, and maximum QRS vectors were compared with similar measurements in 60 control subjects previously reported. New criteria for the vector-cardiographic diagnosis of left ventricular hypertrophy have been outlined. Close agreement with earlier reported groups of patients with anteroseptal and anterolateral infarction was found, and findings by others in patients with left ventricular hypertrophy were confirmed. The direction of the 0.02-second QRS vector allowed the separation of the infarct group from the left ventricular hypertrophy group and from the normal, whereas the direction of the 0.03-second and maximum QRS vectors separated left ventricular hypertrophy from the normal. The magnitude of the maximum QRS vector is another highly reliable indicator of left ventricular hypertrophy and also serves to separate this group from those with associated anterior wall infarct. The influence of associated right ventricular hypertrophy or posterobasal infarction on left ventricular hypertrophy has been discussed. The accuracy of this technic of vectorcardiographic differentiation between left ventricular hypertrophy on the one hand and left ventricular hypertrophy with anterior infarction on the other in every instance was confirmed at autopsy. In all 12 patients whose electrocardiograms presented the dilemma of QS or rS complexes in leads V 1 to V 3 of the standard precordial electrocardiogram, the vectorcardiographic diagnosis was confirmed at autopsy. The Frank vectorcardiogram is a sensitive and reliable method to recognize left ventricular hypertrophy and may prove to be a useful adjunct to the ordinary electrocardiogram in cases where the electrocardiographic diagnosis is questionable.