Use of the Vectorcardiogram to Recognize Right Ventricular Hypertrophy in Mitral Stenosis

The vectorcardiograms of 44 patients with dominant mitral stenosis were correlated with hemodynamic data. Correlations were made between several quantitative VCG criteria and peak right ventricular pressure, mean pulmonary artery pressure, total pulmonary resistance and mitral valve area. Regression equations were obtained which allow prediction of hemodynamic data from several readily obtainable vectorcardiographic measurements. Four groups were defined based on the configuration of the Frank horizontal QRS loop. Significant hemodynamic differences were found for each group. Of special note was the finding of patients with type C loops but whose electrocardiograms were not clearly diagnostic of right ventricular hypertrophy. Of interest also was the finding of patients with the type C loop with severe hemodynamic changes, as opposed to what is suggested in the literature and what is seen in congential heart diseases. When the standard scalar electrocardiogram shows unequivocal right ventricular hypertrophy the patient invariably has serious mitral stenosis and severe pulmonary hypertension.