Pre- and post-operative right ventricular functions in valvular heart diseases: the significance of noninvasive assessment

This investigation was undertaken to evaluate right ventricular function in valvular heart diseases by calculating right ventricular ejection fraction (RVEF) from first-pass radionuclide angiography (RNA). One hundred cases of valvular heart disease were examined by RNA, 93 of whom underwent cardiac catheterization and contrast left ventriculography, preoperatively. Fifty of the 100 cases were examined by RNA; 18 by cardiac catheterization post-operatively. The results were as follows: 1. In 49 cases of mitral valve disease, there was a correlation (r = -0.75) between pulmonary artery mean pressure (PAm) and RVEF. This suggested that afterload of left atrial pressure elevation induced a decrease in RVEF. 2. Although PAm did not increase so much in aortic valve disease, RVEF decreased in some cases, especially in those having massive aortic stenosis or regurgitation. In 22 cases of aortic regurgitation which had normal PAm and a left ventricular-aortic systolic pressure gradient less than 50 mmHg, there was a correlation (r = -0.69) between the RVEF and the left ventricular end-diastolic volume index (LVEDVI). 3. Although post-operative RVEF did not improve significantly in mitral valve disease, it increased significantly in the early post-operative period in aortic valve disease. Also, the increase in RVEF and the decrease in LVEDVI seemed to correlate closely in aortic valve disease. It was speculated that pre-operative decrease of RVEF is derived from a deformity of the RV caused by pressure from the enlarged or thickened LV, and that post-operative increase of RVEF is dependent upon a decrease of LV size and volume.