Zhou Suping, Chen Peng, Li Huijie, Zeng Chunyu, Fang Yuqiang, Shi Weibin, Yang Chengming
Acta Cardiol. 2016 Apr;71(2):199-203. doi: 10.2143/AC.71.2.3141850.
The objective of this study was to assess the clinical value of cardiac output (CO) measurements using the inert gas rebreathing (IGR) method during the 6-minute walk test (6MWT) in evaluation of chronic heart failure (CHF).
A total of 56 CHF patients in our hospital who conformed to the Framingham CHF diagnostic criteria were recruited to this study from October 2007 to February 2009. Subjects were asked to complete a 6MWT and a bicycle exercise test. The CO was measured during both tests using IGR. B-type natriuretic peptide (BNP) levels and the left ventricular ejection fraction (LVEF) were measured at rest. The 6MWT did not correlate with BNP, LVEF, peak cardiac output (PCO), or CO during the 6MWT (CO6MWT). A negative correlation between CO6MWT and BNP as well as a strong correlation between CO6MWT and PCO was observed. When atrial fibrillation and valvular heart disease patients were excluded, CO6MWT and LVEF became significantly correlated. After grouping patients into tertiles according to their PCO values, the PCO remained correlated with CO6MWT within each group. The mean difference between CO6MWT and PCO decreased with decreases in the mean PCO in each group. No significant differences were found in the third tertile (PCO < 10.1 L/min).
The IGR method during 6MWT is safe and reliable to evaluate cardiac function in patients with CHF.
本研究旨在评估在6分钟步行试验（6MWT）期间使用惰性气体再呼吸（IGR）方法测量心输出量（CO）在评估慢性心力衰竭（CHF）中的临床价值。
2007年10月至2009年2月，我院共招募了56例符合Framingham CHF诊断标准的CHF患者参与本研究。受试者被要求完成一次6MWT和一次自行车运动试验。在两项试验期间均使用IGR测量CO。在静息状态下测量B型利钠肽（BNP）水平和左心室射血分数（LVEF）。6MWT与BNP、LVEF、峰值心输出量（PCO）或6MWT期间的心输出量（CO6MWT）均无相关性。观察到CO6MWT与BNP之间呈负相关，CO6MWT与PCO之间呈强相关。排除心房颤动和心脏瓣膜病患者后，CO6MWT与LVEF显著相关。根据PCO值将患者分为三分位数组后，每组内PCO与CO6MWT仍相关。每组中，CO6MWT与PCO之间的平均差异随着平均PCO的降低而减小。在第三三分位数组（PCO < 10.1 L/min）中未发现显著差异。
6MWT期间的IGR方法在评估CHF患者心功能方面安全可靠。
