Mitral stenosis: Hemodynamic,electrocardiographic, and vectorcardiographic studies

The data of transseptal left heart and right heart catheterization were correlated with the phonocardiographic, electrocardiographic, and vectorcardiographic findings in 75 patients with significant mitral stenosis. Measurement of the rate of the “y” descent in the first tenth of a second after the opening of the mitral valve was helpful in detecting the presence of significant mitral stenosis. In the absence of tachycardia, the value of the formula P1-P2MLAP role=presentation style=font-size: 90%; display: inline-block; position: relative;>$\text{P}{}_1\text{-P}{}_2\text{MLAP}$$\text{P}{}_1\text{-P}{}_2\text{MLAP}$ was 0.3 or less among patients who had predominant mitral stenosis. No significant difference was seen between patients with normal sinus rhythm and those with atrial fibrillation. In the 54 available phonocardiograms, Q-1 minus 2-O.S. was equal to or greater than 0 in all but 7 patients. The electrocardiograms revealed evidence of right ventricular hypertrophy in 26 instances, whereas the vectorcardiograms revealed evidence of right ventricular hypertrophy in 31 instances. Forty-one patients had neither electrocardiographic nor vectorcardiographic evidence of isolated right ventricular hypertrophy. Both the electrocardiogram and vectorcardiogram failed to show patterns typical of right ventricular hypertrophy in 15 patients despite the significantly elevated resting right ventricular pressure. There were 9 patients who had posterior displacement of the QRSsÊ loop.