Abstract
Objective: It was shown that percutaneous balloon mitral valvuloplasty (PMBV) has provided symptomatic improvement in cases with mitral stenosis. The purpose of this study was to investigate the influences of successful PBMV on cardiopulmonary exercise test (CPET) in patients with mitral stenosis early after intervention. Methods: Twenty-nine patients with mitral stenosis were included in this study. Nineteen patients had undergone PBMV and ten patients were studied as control group. An incremental symptom limited CPET was carried out within the 24 hours before the PMVB procedure and within the five days thereafter. Breath by breath O2 uptake (VO2) and CO2 production (VCO2) were measured in these subjects. Results: The mean mitral valve area (MVA) in the PBMV group before the procedure was 1.2±0.7 cm2 and the mean pressure gradient (PG) through the mitral valve was 12.63±4.87 mmHg; after the procedure, the mean MVA was 1.9±0.3 cm2 and the mean PG was 4.9±2.3 mmHg. The mean MVA in the control group was 1.4±0.16 cm2 and the mean PG was 7.2±3.54mmHg. In the PBMV group, exercise time was 12.1±6 min before the procedure and increased to 18.75±5.5 min after the procedure (p=0.0001); peak VO2 value rised from 1035±392 ml/min to 1178±373 ml/min (p=0.0001) and VO2 at the anaerobic threshold from 667±286 ml/min to 772±268 ml/min (p=0.006). Peak VO2/HR rised from 10.97±6.10 ml/min to 12.24±7.36 ml/min (p=0.001). No significant difference was observed in the control group. Conclusions: The results of this study demonstrate that successful PBMV causes evident rise in exercise capacity, so that patients can manage the same exercise levels with lower heart rates and more economic ventilation.