The vectorcardiographic quantitation of pulmonary hypertension in mitral stenosis

Hemodynamic data and vectorcardiographic (VCG) parameters were correlated in ninety-nine patients with mitral stenosis in order to quantitate the severity of pulmonary hypertension. Using spherical coordinate representation of VCG parameters as independent variables, multi-parameter regression equations were derived for estimating mean pulmonary artery pressure (PAm) and total pulmonary vascular resistance (TPR). The regression equations of this group of ninety-nine patients performed well when the patients were divided into specific subgroups based on horizontal plane morphology. The correlation co-efficients between estimated and measured values ranged from 0.71 to 0.81 for PAm and 0.68 to 0.80 for TPR. These regression equations were used to predict the PAm and TPR in a second set of 11 patients. The correlation co-efficients between the measured and predicted values for this group were 0.54 for PAm and 0.64 for TPR.