Francis G S
Department of Medicine, University of Minnesota Medical School, Minneapolis.
Circulation. 1987 Dec;76(6 Pt 2):VI11-7.
Exercise testing has assumed a position of growing importance in the assessment of patients with chronic congestive heart failure. The hemodynamic and neurohumoral adjustments that occur during dynamic exercise are very complex, but are basically designed to ensure that oxygen delivery is commensurate with oxygen demand. These responses are clearly altered in the presence of certain types of heart disease. Patients with chronic congestive heart failure have an attenuated heart rate and blood pressure response throughout exercise, but this is most clearly evident when the data are expressed as a percent of peak oxygen consumption (VO2) rather than as a function of absolute VO2. Likewise, the sympathetic response to exercise is altered in patients with heart failure. Plasma norepinephrine is normally augmented as a function of VO2 during exercise, but this augmentation occurs during the later stages (beyond 50% of peak VO2). Patients with congestive heart failure show a greater than normal augmentation of plasma norepinephrine during exercise when the data are expressed in terms of absolute VO2. However, when the data are expressed as a percent of peak VO2, there appears to be a relative attenuation of the sympathetic response to exercise. Current information suggests that increased plasma norepinephrine and renin activity during exercise in patients with heart failure are not directly related to a decrement in nutritive blood flow to skeletal muscles. The mechanisms responsible for exercise intolerance in patients with heart failure are not known, but do not seem directly related to a decrement in cardiac output or an increase in left ventricular filling pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
运动试验在慢性充血性心力衰竭患者的评估中已占据日益重要的地位。动态运动期间发生的血流动力学和神经体液调节非常复杂，但基本上是为了确保氧输送与氧需求相称。在某些类型的心脏病存在时，这些反应会明显改变。慢性充血性心力衰竭患者在整个运动过程中心率和血压反应减弱，但当数据表示为峰值耗氧量（VO2）的百分比而非绝对VO2的函数时，这一点最为明显。同样，心力衰竭患者对运动的交感神经反应也会改变。运动期间，血浆去甲肾上腺素通常会随着VO2的增加而增加，但这种增加发生在后期阶段（超过峰值VO2的50%）。当数据以绝对VO2表示时，充血性心力衰竭患者在运动期间血浆去甲肾上腺素的增加高于正常水平。然而，当数据表示为峰值VO2的百分比时，对运动的交感神经反应似乎相对减弱。目前的信息表明，心力衰竭患者运动期间血浆去甲肾上腺素和肾素活性的增加与骨骼肌营养性血流的减少没有直接关系。心力衰竭患者运动不耐受的机制尚不清楚，但似乎与心输出量的减少或左心室充盈压的增加没有直接关系。（摘要截短至250字）
