Wright D J, Williams S G, Tzeng B-H, Marshall P, Mackintosh A F, Tan L B
Molecular Vascular Medicine, Martin Wing, Leeds General Infirmary, Leeds, UK.
Int J Cardiol. 2003 Sep;91(1):81-91. doi: 10.1016/s0167-5273(02)00591-0.
Procedural technical success of balloon mitral valvuloplasty (BMV) is indicated by an increase in valve area and a reduction in transvalvar gradient, but there are conflicting results regarding whether these indicators correlate with subsequent improvements in exercise capacity. We conducted a study to explore the effects of valvuloplasty on cardiac function to gain insight into the mechanisms responsible for the impact on exercise ability. Sixteen patients with mitral stenosis participated in the study and the five who did not proceed to valvuloplasty served as the control group. All patients performed maximal cardiopulmonary exercise tests before and 6 weeks after valvuloplasty (without valvuloplasty in controls). Central haemodynamics including cardiac output were measured non-invasively at rest and peak exercise. At baseline, the cardiopulmonary exercise test results were similar in the two groups. Following valvuloplasty, cardiac output did not alter at rest, but increased significantly at peak exercise (8.7+/-1.7 to 10.5+/-2.1 l min(-1), P<0.01), as did peak cardiac power output (1.88+/-0.55 to 2.28+/-0.74, P<0.05) and cardiac reserve (1.07+/-0.33 to 1.45+/-0.55 watts, P<0.05). Aerobic exercise capacity improved (13.9+/-4.2 to 16.4+/-4.3 ml kg(-1) min(-1), P<0.01) as did exercise duration (354+/-270 to 500+/-266 s, P<0.01). There were no significant changes in the controls. There was a significant correlation between the changes in peak VO(2) and changes in cardiac reserve (r=0.62, P<0.01) but not with changes in resting haemodynamics. These changes did not correlate with changes in peri-procedural mitral valve haemodynamics, despite increases in mitral valve area from 1.05+/-0.16 to 1.74+/-0.4 cm(2) (P<0.0001), accompanied by falls in the transvalvar gradient and pulmonary artery pressure (12.4+/-4.7 to 4.5+/-3 mmHg, and 26.8+/-8.4 to 17.4+/-5.2 mmHg, respectively, all P<0.0001). In conclusion, we found that successful mitral valvuloplasty in our patient cohort led to improved cardiac and physical functional capacity but not resting haemodynamics. Neither indicators of technical success nor resting haemodynamics were very reliable in predicting functional improvement.
球囊二尖瓣成形术（BMV）的手术技术成功表现为瓣膜面积增加和跨瓣压差降低，但关于这些指标是否与随后运动能力的改善相关，存在相互矛盾的结果。我们进行了一项研究，以探讨瓣膜成形术对心脏功能的影响，从而深入了解影响运动能力的机制。16例二尖瓣狭窄患者参与了该研究，其中5例未进行瓣膜成形术的患者作为对照组。所有患者在瓣膜成形术前及术后6周（对照组未进行瓣膜成形术）均进行了最大心肺运动试验。在静息和运动峰值时，采用非侵入性方法测量包括心输出量在内的中心血流动力学指标。基线时，两组的心肺运动试验结果相似。瓣膜成形术后，静息时的心输出量未改变，但运动峰值时显著增加（从8.7±1.7升至10.5±2.1 l min⁻¹，P<0.01），运动峰值时的心功率输出（从1.88±0.55升至2.28±0.74，P<0.05）和心脏储备（从1.07±0.33升至1.45±0.55瓦，P<0.05）也显著增加。有氧运动能力得到改善（从13.9±4.2升至16.4±4.3 ml kg⁻¹ min⁻¹，P<0.01），运动持续时间也延长（从354±270秒升至500±266秒，P<0.01）。对照组无显著变化。运动峰值时VO₂的变化与心脏储备的变化之间存在显著相关性（r = 0.62，P<0.01），但与静息血流动力学的变化无关。尽管二尖瓣面积从1.05±0.16增加至1.74±0.4 cm²（P<0.0001），同时跨瓣压差和肺动脉压下降（分别从12.4±4.7降至4.5±3 mmHg和从26.8±8.4降至17.4±5.2 mmHg，均P<0.0001），但这些变化与围手术期二尖瓣血流动力学的变化无关。总之，我们发现我们的患者队列中成功的二尖瓣成形术导致心脏和身体功能能力改善，但静息血流动力学未改善。技术成功指标和静息血流动力学在预测功能改善方面均不太可靠。
