Characterization of the Circulatory Response to Maximal Upright Exercise in Normal Subjects and Patients with Heart Disease
Characterization of the Circulatory Response to Maximal Upright Exercise in Normal Subjects and Patients with Heart Disease
复制标题
正常受试者和心脏病患者对最大直立运动的循环反应特征
作者：
S. Epstein;G. Beiser;M. Stampfer;B. Robinson;E. Braunwald
研究人员研究了 6 名正常受试者和 21 名患有各种类型心脏病的患者对轻度和最大直立运动的循环反应。研究发现，用于评估运动期间心脏功能的常用血流动力学指标在区分患者和正常人方面并不可靠。相比之下，肺动脉 (PA) O2 饱和度为 30% 时获得的心脏指数对于区分运动的正常反应和异常反应具有高度的可靠性和敏感性。在将 PA O2 饱和度降低至 30% 的运动水平下，所有正常受试者的心脏指数均大于 7.0 L/minm2，而没有患者超过 4.8 L/min/m2。此外，患者的最大吸氧能力高于正常受试者；因此，在最大运动期间，患者的 PA O2 饱和度达到 15% 或更低并不罕见，而正常受试者达到的最低值为 23%。
The circulatory responses to mild and maximal upright exercise were studied in six normal subjects and 21 patients with various types of cardiac disease. It was found that the usual hemodynamic indices employed to evaluate cardiac performance during exertion were unreliable in separating patients from normal persons. In contrast, the cardiac index achieved at a pulmonary arterial (PA) O2 saturation of 30% was found to be highly reliable and sensitive for distinguishing the normal from the abnormal response to exercise. At a level of exercise that lowers PA O2 saturation to 30%, all normal subjects achieved a cardiac index greater than 7.0 L/minm2 while no patient exceeded 4.8 L/min/m.2 In addition, the maximal capacity to extract O2 was greater in patients than in normal subjects; thus, during maximal exercise it was not unusual for patients to achieve PA O2 saturations of 15% or less, while the lowest value achieved in normal subjects was 23%.