Immediate and long-term effect of mitral balloon valvotomy on left ventricular volume and systolic function in severe mitral stenosis

To determine the immediate and long-term effect of mitral balloon valvotomy (MBV) on left ventricular (LV) volume and function, we studied 17 patients (mean age 27 ± 9 years) with severe mitral stenosis undergoing MBV by cardiac catheterization and angiography before and immediately after MBV and at mean 12 months later. At baseline, LV end-diastolic volume index (EDVI) was reduced. Ten patients had EDVI ≤55 ml/m2, and four patients (23.5%) had LV ejection fraction <50%. EDVI increased from 60 ± 17 ml/m2 to 66 ± 17 ml/m2 (p < 0.05) immediately after MBV and increased further to 72 ± 16 ml/m2 (p < 0.05) later. Stroke volume index increased from 34 ± 10 ml/m2 to 41 ± 12 ml/m2 (p < 0.05) immediately after MBV and increased further to 50 ± 11 ml/m2 (p < 0.001) later. LV end diastolic pressure increased from 12 ± 5 mm Hg to 16 ± 4 mm Hg (p < 0.05) immediately after MBV and fell to 13 ± 3 mm Hg at follow-up. LV ejection fraction increased from 57 ± 7% to 62 ± 6% (p < 0.05) immediately after MBV and 71 ± 8% later (p < 0.001). Mean systolic ejection rate increased from 82 ± 35 ml/sec to 101 ± 48 ml/sec (p < 0.05) immediately after and 165 ± 81 ml/sec later (p < 0.05). Systemic vascular resistance fell from 1887 ± 525 dyne/sec/cm−5 to 1280 ± 231 dyne/sec/cm−5 (p < 0.001) at follow-up. We conclude that the LV end-diastolic volume and systolic function are reduced in patients with mitral stenosis, and the LV end-diastolic volume is increased immediately after MBV and continues to increase at follow-up 12 months later; the LV ejection performance improves after successful MBV because of an increase in end-diastolic LV volume (preload) and reduction of SVR (after-load).