Effects of percutaneous balloon mitral valvuloplasty and exercise training on the kinetics of recovery oxygen consumption after exercise in patients with mitral stenosis

Abstract

Aims. Kinetics of recovery oxygen consumption after exercise plays an important role in determining exercise capacity. This study was performed to assess the kinetics of recovery oxygen consumption in mitral stenosis and evaluate the effects of percutaneous balloon mitral valvuloplasty and exercise training on the kinetics. Methods and Results. Thirty patients with mitral stenosis (valve area ≤ 1.0 cm2) and same sized age- and size-matched healthy volunteers were included for this study. All subjects performed maximal upright graded bicycle exercise. Thirty consecutive patients who underwent successful percutaneous balloon mitral valvuloplasty (valve area ≥ 1.5 cm2 and mitral regurgitation grade ≤ 2), were randomized to an exercise training group or non-training group. The exercise group performed daily exercise training for 3 months. Half-recovery time of peak oxygen consumption was significantly delayed in mitral stenosis as compared to normal subjects (120 ± 42 s vs 59 ± 5, P < 0.01). Peak oxygen consumption (ml.min-1.kg-1) was significantly increased in both the training (16.8 ± 4.9 to 25.3 ± 6.9) and non-training groups (16.3 ± 5.1 to 19.6 ± 6.0) 3 months after percutaneous balloon mitral valvuloplasty. Half-recovery time of peak oxygen consumption was significantly shortened in the training group (124 ± 39 to 76 ± 13, P < 0.01), but not in the non-training group (114 ± 46 to 109 ± 44 s, P = 0.12) at 3 months followup. The degrees of symptomatic improvement after percutaneous balloon mitral valvuloplasty were more closely correlated with the changes of the half-recovery time of peak oxygen consumption than those of peak oxygen consumption. Conclusion. Kinetics of recovery oxygen consumption was markedly delayed in mitral stenosis, which was improved after exercise training but not after percutaneous balloon mitral valvuloplasty alone. These results suggest that adjunctive exercise training may be useful for improvement of recovery kinetics and subjective symptoms after percutaneous balloon mitral valvuloplasty.