Weber K T, Janicki J S
Am J Cardiol. 1985 Jan 11;55(2):22A-31A. doi: 10.1016/0002-9149(85)90792-1.
The heart, lungs and hemoglobin form the body's gas transport system, which links the atmosphere and its supply of O2 with tissue, while simultaneously providing for the elimination of the metabolic end-product, CO2, into the atmosphere. The transport of these respiratory gases must be in accordance with metabolic need. This is particularly evident during the physiologic stress of isotonic exercise, when the O2 requirements and CO2 production of skeletal muscle are increased. The monitoring of these respiratory gases during exercise, referred to as cardiopulmonary exercise testing (CAR-PET), can be used to assess heart and lung function in patients with cardiovascular or lung disease or both. Chronic cardiac failure (CCF) may be defined in physiologic terms as that circumstance in which the heart fails to provide tissue with O2 at a rate commensurate with aerobic requirements. In patients with CCF, CAR-PET represents a noninvasive means to determine aerobic capacity (that is, maximal O2 uptake) and anaerobic threshold during incremental treadmill exercise. It can also provide an objective measure of the severity of failure, the functional status of the patient and the heart's pump reserve. By using additional measurements of ventilation, arterial O2 saturation and, in selected cases, hemodynamic monitoring, the nature and severity of cardiovascular and pulmonary disease may be evaluated.
心脏、肺和血红蛋白构成了人体的气体运输系统，该系统将大气及其氧气供应与组织联系起来，同时将代谢终产物二氧化碳排放到大气中。这些呼吸气体的运输必须符合代谢需求。这在等张运动的生理应激期间尤为明显，此时骨骼肌的氧气需求和二氧化碳产生量会增加。在运动期间对这些呼吸气体进行监测，即心肺运动试验（CAR-PET），可用于评估患有心血管疾病或肺部疾病或两者兼有的患者的心肺功能。慢性心力衰竭（CCF）在生理上可定义为心脏无法以与有氧需求相称的速率为组织提供氧气的情况。在CCF患者中，CAR-PET是一种在递增式跑步机运动期间确定有氧能力（即最大摄氧量）和无氧阈值的非侵入性方法。它还可以提供心力衰竭严重程度、患者功能状态和心脏泵血储备的客观指标。通过使用通气、动脉血氧饱和度的额外测量，以及在特定情况下进行血流动力学监测，可以评估心血管和肺部疾病的性质和严重程度。
