Messner-Pellenc P, Ximenes C, Leclercq F, Mercier J, Grolleau R, Préfaut C
Services de Cardiologie, Hopital Arnaud de Villeneuve, Montpellier, France.
Eur Heart J. 1996 Apr;17(4):595-605. doi: 10.1093/oxfordjournals.eurheartj.a014914.
The aim of this study was to specify in patients with tight mitral stenosis whether lung diffusing capacity could play a role in their exercise intolerance. A similar study was recently carried out in patients with moderate chronic heart failure. Ten patients with tight mitral stenosis were studied before and 6 months after successful percutaneous transvenous balloon valvuloplasty and compared to six control subjects. Measurements of diffusing capacity, evaluated by the lung transfer factor (TLCO) and by the transfer coefficient (TLCO/VA), obtained at rest and during early recovery after cardiopulmonary exercise testing were performed. Cardiac output was determined non-invasively, both at rest and during exercise, using the carbon dioxide exponential rebreathing technique. Prior to valvuloplasty, TLCO and TLCO/VA were not different at rest between the two groups. During exercise, patients differed from control subjects, with lower oxygen uptake (P < 0.001) and lower cardiac output at peak exercise (P < 0.001). These values at peak exercise were significantly correlated (P = 0.02; r = 0.75). Moreover, patients differed from control subjects at early recovery after peak exercise with an absence of increase in TLCO (P < 0.05). Six months after valvuloplasty, a decrease of both TLCO (P < 0.01) and TLCO/VA (P < 0.05) was observed at rest. During exercise, comparison of patients demonstrated a significant increase of both peak exercise oxygen uptake (SLVO2, P < 0.01) and cardiac output (P < 0.001). At early recovery after peak exercise there was a significant increase in TLCO (P < 0.05) and TLCO/VA (P < 0.01), such that a delta TLCO and a delta TLCO/VA appeared (P < 0.05) identical to that observed in control subjects. Moreover, delta SLVO2 was significantly correlated in patients with delta Q+ delta TLCO/VA (P = 0.02; r = 0.72). In conclusion, this study suggests a role, at least partial, of lung diffusing capacity in exercise intolerance in patients with tight mitral stenosis and in the improvement of their aerobic exercise capacity demonstrated after successful percutaneous balloon valvuloplasty.
本研究的目的是明确在重度二尖瓣狭窄患者中，肺弥散功能是否在其运动不耐受中起作用。最近对中度慢性心力衰竭患者进行了一项类似研究。对10例重度二尖瓣狭窄患者在成功进行经皮经静脉球囊瓣膜成形术前及术后6个月进行研究，并与6名对照受试者进行比较。在静息状态和心肺运动试验后的早期恢复阶段，通过肺转移因子（TLCO）和转移系数（TLCO/VA）评估弥散功能。使用二氧化碳指数再呼吸技术在静息和运动期间无创测定心输出量。在瓣膜成形术前，两组静息时的TLCO和TLCO/VA无差异。运动期间，患者与对照受试者不同，运动峰值时氧摄取量较低（P<0.001），心输出量较低（P<0.001）。这些运动峰值时的值显著相关（P = 0.02；r = 0.75）。此外，患者在运动峰值后的早期恢复阶段与对照受试者不同，TLCO没有增加（P<0.05）。瓣膜成形术后6个月，静息时TLCO（P<0.01）和TLCO/VA（P<0.05）均降低。运动期间，患者的比较显示运动峰值氧摄取量（SLVO2，P<0.01）和心输出量（P<0.001）均显著增加。在运动峰值后的早期恢复阶段，TLCO（P<0.05）和TLCO/VA（P<0.01）显著增加，使得出现了与对照受试者中观察到的相同的ΔTLCO和ΔTLCO/VA（P<0.05）。此外，患者的ΔSLVO₂与ΔQ + ΔTLCO/VA显著相关（P = 0.02；r = 0.72）。总之，本研究表明肺弥散功能在重度二尖瓣狭窄患者的运动不耐受中至少起部分作用，并且在成功进行经皮球囊瓣膜成形术后其有氧运动能力得到改善。
