Response of left ventricular ejection performance following balloon valvuloplasty in patients with mitral stenosis

In order to see if any change of left ventricular ejection performance (LEVP) would occur after successful balloon mitral valvuloplasty (BMV), a prospective study on echocardiography and calibrated carotid pulse tractings was performed two days before, two days and then six months after BMV in 24 patients with pure rheumatic mitral stenosis (MS). Echocardiographic parameters representing preload i.e. end-diastolic volume index (EDVI); afterload i.e. end-systolic wall stress (ESS), and the indices of LVEP i.e. ejection fraction (EF), fractional shortening, rate-corrected velocity of circumferential shortening (VCFc) and a ratio of ESS over end-systolic volume index (ESS/ESVI) were measured. A group of 66 normal subjects was used to establish the 95% confidence interval of the echo parameters. The incidence of depressed LVEP in MS patients was about 21% when measured by load-independent index i.e. ESS/ESVI. In the MS group, 7 out 24 (29%) patients achieved an increased cardiac index after BMV. Six (25%) MS patients showed an EF below 95% confidence interval of control (less than 55%) before BMV and, of these 6, only 3 patients increased their EDVI after the BMV. Those who showed an EF greater than or equal to 55% before BMV gave no change in their preload (EDVI) after the BMV. Only one MS patient showed high afterload (ESS) both before and after BMV. However, the ESS/ESVI showed insignificant improvement (p = 0.055) after BMV. It was therefore concluded that (1) a depressed LVEP is frequently seen in patients with MS; (2) LVEP can be improved by BMV in some (21%) patients with MS, and the improvement is not related to the change of preload or afterload but more likely secondary to an increased myocardial contractility.