An improved index of left ventricular function in chronic mitral regurgitation.

The ratio of end-systolic wall stress (ESWS) to volume index (ESVI) has been proposed as a useful index of left ventricular (LV) function in chronic mitral regurgitation (MR). However, although this ratio reflects isometric contraction, the chronic changes in LV architecture caused by MR may affect its usefulness. An index was evaluated that incorporated the ejection fraction--(TVEF [tension-volume ejection fraction] = ESWS/ESVI X EF)--thus combining both isometric and ejection phase parameters. Forty patients with symptomatic MR but no other valvular or coronary disease had valve replacement between 1980 and 1984. Twenty-nine patients (group A) were in New York Heart Association class I or II postoperatively. The remaining patients (group B) were in class III or IV or died. Four preoperative LV function indexes were compared. The means of all indexes in groups A and B were significantly different, but only TVEF completely separated the groups. A TVEF of less than 1.47 uniformly predicted a poor operative outcome.