Exercise performance after PTMC in mitral stenosis: the relation with hemodynamics, ventilatory response and skeletal muscle function.
We examined the contribution of hemodynamics, ventilatory response and skeletal muscle function to the exercise performance after percutaneous transvenous mitral commissurotomy (PTMC). Nine patients with mitral stenosis (MS) underwent symptom-limited maximal ergometer exercise before, at 1 week and 3 months after PTMC. At 3 months after PTMC four patients (group 1) revealed an improved exercise performance (peak oxygen uptake (VO2) 747 +/- 145 to 1,039 +/- 175 ml/min; p < 0.01), and five patients (group 2) showed an unchanged exercise performance. Exercise performance in group 1 already increased at 1 week after PTMC. Peak cardiac output (Q) in group 1 increased (4.9 +/- 0.7 to 6.9 +/- 1.0 L/min, p < 0.05) at 3 months after PTMC. The slope of the minute ventilation (VE)-carbon dioxide production (VCO2) relation during exercise decreased at 1 week after PTMC (40.2 +/- 4.2 to 30.5 +/- 3.8, p < 0.05), and decreased slope of VE-VCO2 remained at 3 months after PTMC. However in group 2 these parameters did not change. There was a significant correlation between percent change of peak VO2 and percent change of peak Q from before to 3 months after PTMC (r = 0.84, p < 0.01). However there were no differences in reduction of mean pulmonary artery pressure, pulmonary vascular resistance and maximum isometric force (MIF) of left quadriceps between two groups. These findings suggest that the increased Q and improved excessive ventilation were important for increase in exercise performance in patients with MS after PTMC.
Kakimoto
T
T
Department of Internal Medicine, Kobe University School of Medicine.
Yamabe
H
H
Yokoyama
M
M
D005080:Exercise Test; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008946:Mitral Valve Stenosis / Q000503:physiopathology* / Q000601:surgery*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D005082:Physical Exertion; D011184:Postoperative Period; D012119:Respiration