[Usefulness of measuring right ventricular anterior wall thickness in patients with right ventricular overload using M-mode echocardiography].

Right ventricular anterior wall thickness measured by M-mode echocardiography and right ventricular systolic pressure obtained by right heart catheterization were correlated in 62 patients with chronic right ventricular overload including congenital heart disease and primary pulmonary hypertension. The patients were divided into two groups; one, with right ventricular systolic pressures of 39 mmHg or less; the other, 40 mmHg or more. The following results were obtained. 1. The correlation coefficient for right ventricular anterior wall thickness and right ventricular systolic pressure was r = 0.90 (p less than 0.001), and the regression equation was y = 13.2x-1.3. 2. Right ventricular end-diastolic dimension increased significantly in both groups, but no statistically significant differences were detected between the two. Right ventricular anterior wall thickness increased significantly in the group with higher right ventricular pressures (7.1 +/- 0.5 mm vs 3.1 +/- 0.5 mm). 3. When right ventricular anterior wall thickness was more than 4.0 mm, pulmonary hypertension was detected, with a sensitivity of 97.5% and a specificity of 90.9%. In conclusion, measurements of right ventricular anterior wall thickness by M-mode echocardiography via the anterior chest wall proved to be potentially useful in predicting right ventricular systolic pressures in patients with chronic right ventricular overloads.