EFFECT OF CHF O2 TRANSPORT & UPTAKE KINETICS DURING REST TO WORK TRANSITION

CHF O2 传输的影响

• 批准号: 6265926
• 负责人: JOEL KEVIN SHOEMAKER
• 金额: $ 3.26万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-12-01 至 1999-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6265926
• 关键词: clinical research; congestive heart failure; edema; exercise; human subject; limbs; muscle metabolism; oxygen transport

Patients suffering from CHF are limited in their exercise tolerance. One factor leading to the reduced exercise tolerance is believed to involve attenuated oxygen transport to active muscle. In previous reports, peripheral blood flow measures have been used as an index of oxygen transport but there is a disagreement as to whether or not CHF alters the peripheral regulation of blood flow. Among other factors, this uncertainty may be due to differences in oxygen carrying capacity in heterogeneous groups of CHF patients. Lower oxygen carryinmg capacity may result in augmented flow responses in an attempt to optimize oxygen delivery. However, it seems clear that an augmented oxygen extraction from a normal flow response cannot compensate leading to an early activation of muscle glycolosis. A critical factor may be the rate at which oxygen transport increases at the onset of exercise (i.e. oxygen transport kinetics) It is known that a slowed adaption to the onset of exercise can slow the rate at which oxygen uptake occurs (i.e. the rate of delivery may limit the rate of oxygen uptake) thereby increasing the oxygen deficit incurred at the exercise onset, leading to an early and accelerated release of lactate and hydorgen ion. These metabolites are believed to be instrumental in the development of fatigue. The objectives of this study are to investigate the effect of CHF on the rate of increase in blood flow during the transition from rest to steady state handgrip exercise. A second objective is to examine the consequent effect of slowed blood flow kinetics on muscle metabolism. A third objective is to asses the role of forearm edema in the blood flow and oxygen uptake time course. We believe that CHF is associated with a slowed rate of increase in oxygen transport at the onset of exercise. The slower blood flow response may be due to slowed vasodilation and to limb edema.

慢性心力衰竭患者的运动耐受性有限。导致运动耐受性降低的一个因素被认为与向活动肌肉输送的氧气减少有关。在以前的报道中，外周血流量测量已被用作氧运输的指标，但对于CHF是否改变外周血流量调节存在分歧。除其他因素外，这种不确定性可能是由于异质组CHF患者携带氧能力的差异。较低的携氧能力可能导致增强的流动反应，以优化氧气输送。然而，似乎很清楚的是，从正常血流反应中增加的氧气提取不能补偿导致肌糖酵解的早期激活。一个关键因素可能是运动开始时氧运输增加的速度（即氧运输动力学）。众所周知，对运动开始的缓慢适应可以减慢氧摄取发生的速度（即输送速度可能限制氧摄取的速度），从而增加运动开始时发生的氧不足，导致乳酸和氢离子的提前和加速释放。这些代谢物被认为是疲劳发展的工具。本研究的目的是研究CHF对从静止到稳定状态握力运动过渡期间血流量增加速率的影响。第二个目的是研究血流动力学减慢对肌肉代谢的影响。第三个目的是评估前臂水肿在血流和摄氧量过程中的作用。我们认为CHF与运动开始时氧气运输增加速度减慢有关。血流反应较慢可能是由于血管舒张减慢和肢体水肿。