轻中度慢性阻塞性肺疾病患者运动的心脏反应

目的:慢性阻塞性肺疾病(COPD)增加了心血管疾病的风险,因此COPD引起的运动能力减低不能排除与心脏因素有关。本研究目的是探讨轻-中度COPD患者是否存在心功能异常,从而加重了由于肺功能受损导致的运动能力减低。方法:42例COPD患者及26例正常对照做递增功率运动试验,同步实时测定摄氧量(VO2)和二氧化碳排出量(VCO2),其中有19例COPD患者和18例正常受试者在1周内进行恒功率运动测试,并且在运动前和运动中抽取静脉血,测定氨基酸末端脑钠素前体(NT-proBNP)。结果:COPD患者的最大摄氧量(peak VO2)及恒功率运动时间(CWET)明显低于正常对照组〔peak VO2:(15.81±3.65)vs(19.19±6.16)mL.min-1.kg-1,P=0.035;CWET:(7.78±6.53)min vs(14.77±7.33)min,P=0.015〕。2组的无氧阈、氧脉搏和心率储备差异均无统计学意义。恒功率运动前后2组的血浆NT-proBNP比较显示,COPD组高于对照组,但差异无统计学意义。COPD患者运动前后的NT-proBNP与CWET的相关分析无显著相关。结论:轻-中度COPD患者运动的心脏反应正常,心脏因素可能不是引起这些患者运动受限的原因之一。

Cardiac response to exercise in mild-to-moderate chronic obstructive pulmonary disease

Objective:Chronic obstructive pulmonary disease(COPD) increases the risk of cardiovascular problem.The heart factor can not be excluded from some factors contributing to causing exercise intolerance in COPD.The study objective was to determine whether cardiac dysfunction adds to the mechanism of exercise intolerance caused mainly by impaired lung function in patients with mild-to-moderate COPD.Method:Forty two patients with COPD and twenty six healthy controls performed incremental exercise testing.Oxygen uptake(VO_2) and carbon dioxide output(VCO_2) were measured breath-by-breath.Nineteen of COPD patients and eighteen of the health subjects performed constant work rate testing within one week after finishing incremental exercise testing.Venous blood samples were collected from these subjects before and during constant work exercise for analysis of N-terminalpro-BNP(NT-pro-BNP).Result:Peak oxygen uptake and constant work exercise time(CWET) were significantly lower in COPD group than in control group(15.81±3.65) vs(19.19±6.16) mL·min~(-1)·kg~(-1),P=0.035 and(7.78±6.53) min vs(14.77±7.33) min,P=0.015.Anaerobic shreshold,oxygen pulse and heart rate reserve were not statistically different between COPD group and control group.The NT-pro-BNP levels both at rest and during constant work exercise were higher in COPD group compared to control group,but without statstical significance.The correlations between CWET and NT-proBNP at rest or during exercise in patients with COPD were not statistically significant.Conclusion:The cardiac response of patients with mild-to-moderate COPD to exercise is normal.The heart may not be one of the factors contributing to exercise intolerance in mild-to-moderate COPD.