Résumé
Mitral stenosis is characterized by chronic pulmonary arterial hypertension. Although it is well recognized that right ventricle can be affected by pressure-overload in patients with mitral stenosis, the study for effects on right ventricular function after relief of pressure overload was difficult after open heart surgery due to paradoxical septal motion and scarring change of pericardium. Recently, percutaneous mitral valvuloplasty(PMV) has been used in patients with mitral stenosis as an alternative to surgical mitral commissurotomy. The present study was designed to demonstrate the difference of right ventricle between normal subjects and patients with mitral stenosis, as well as to investigate the changes of right ventricle before and after PMV with Doppler- echocardiography and isovolumic indices. The results were summarized as follows : 1) Right ventricular emptying fraction which was assumed to be proportional to right ventricular ejection fraction was depressed significantly in patients with mitral stenosis than those of normal subjects. However, there were no sighificant differences in Vpm between the two groups. 2) Right atrial and ventricular areas of patients with mitral stenosis were enlarged significantly than those of normal subjects. Right ventricular diastolic function measured by transtricuspid pulsed Doppler showed relaxation abnormality pattern in patients with mitral stenosis. 3) Enlarged right atrium and ventricular area were decreased significantly after PMV. Depressed right ventricular sytolic and diastolic function were recovered after relief of pressure-overload by PMV. However, there were no significant changes in Vpm after PMV. 4) Right ventricular emptying fraction was inversely correlated with mean pulmonary artery pressure and right ventricular end-diastolic area. Discriminant factor between group with right ventricular diastolic dysfunction and group without diastolic dysfunction was pulmonary vascular resistance. In conclusion, there were right ventricular systolic and diastolic dysfunction without abnormal right ventricular contractility in patients with mitral stenosis, moderate pulmonary hypertension and normal sinus rhythm, and these functional abnormalities were largery reversible after relief of pressure-overload on the right ventricle by PMV.