[Early and late physiological effects of balloon mitral valvuloplasty]

To evaluate the early and late cardiorespiratory responses after balloon mitral valvuloplasty.

Nine female patients aged 35 +/- 9 years with mitral stenosis, in class II or III (NYHA) underwent up-right ergoespirometric test, resting electrocardiogram and echocardiogram before, 3 to 5 days (early evaluation) and 8 to 12 months (late evaluation) after mitral valvuloplasty. All patients were treated with digitalis and diuretics.

During late evaluation, 44% patients were in class II and 56% were in class I (NYHA). The resting heart rate decreased (87 +/- 11 bpm vs 85 +/- 7 bpm vs 75 +/- 9 bpm) and the number of steps increased (4 +/- 1 steps vs 5 +/- 2 steps vs 6 +/- 1 steps); the peak oxygen uptake improved only in the late evaluation (16 +/- 3 mL/kg/min vs 18 +/- 4 mL/kg/min vs 22 +/- 7 mL/kg/min). The anaerobic threshold, minute ventilation (VE) and ventilatory equivalent for oxygen showed no change. The heart rate (1st step: 124 +/- 18 bpm vs 112 +/- 13 bpm vs 87 +/- 15 bpm), O2 uptake (1st step: 10 +/- 2 mL/ kg/min vs 8 +/- 2 mL/kg/min vs 8 +/- 2 mL/kg/min) and VE decreased during submaximal exercise in early and late phases. The mitral valve area decreased in the late evaluation (0.94 cm2 vs 1.66 cm2 vs 1.20 cm2).

Although partial restenosis tended to occur in these patients, they improved the functional class and cardiorespiratory performance and cardiocirculatory load during submaximal exercise.