Bussières L M, Pflugfelder P W, Menkis A H, Novick R J, McKenzie F N, Taylor A W, Kostuk W J
Faculty of Kinesiology, University Hospital, University of Western Ontario, London, Canada.
J Heart Lung Transplant. 1995 Nov-Dec;14(6 Pt 1):1073-80.
To evaluate the physiologic basis for the suboptimal peak oxygen uptake observed after heart transplantation, we calculated the functional aerobic impairment ([(peak predicted oxygen uptake-peak observed oxygen uptake)/peak predicted oxygen uptake] x 100) and related it to donor/recipient, operative, and maximal exercise variables. Fifty-seven heart transplant recipients (mean age 50 +/- 10 years, 1 to 9 years after transplantation) underwent maximal upright cycle exercise testing. Concomitant exercise central hemodynamic measurements were obtained in 36 patients (63%).
The mean peak oxygen uptake was 21.7 +/- 6.5 ml/kg/min and functional aerobic impairment was 34% +/- 17%. Functional aerobic impairment correlated positively (p < 0.01) with peak systemic vascular resistance (r = 0.55) and negatively with peak cardiac index (r = -0.62) and peak systemic arteriovenous oxygen difference (r = -0.66). A weak correlation was found between functional aerobic impairment and the duration of cardiac disease (r = 0.35, p < 0.01) but not the origin of heart failure. No correlation was seen between functional aerobic impairment and donor age, total ischemic time, time since transplantation, recipient age, and resting and exercise right and left ventricular filling pressures.
These results suggest that the decreased exercise capacity observed in heart transplant recipients is in part due to increased peripheral vascular resistance and decreased oxygen extraction possibly due to skeletal muscle atrophy. These factors may be the result of irreversible changes from long-standing heart disease, deconditioning, or the effect of cyclosporine and prednisone.
为评估心脏移植后观察到的峰值摄氧量未达最佳水平的生理基础，我们计算了功能性有氧损害（[(预测峰值摄氧量 - 观察到的峰值摄氧量)/预测峰值摄氧量]×100），并将其与供体/受体、手术及最大运动变量相关联。57例心脏移植受者（平均年龄50±10岁，移植后1至9年）接受了最大直立周期运动测试。36例患者（63%）同时进行了运动中心血流动力学测量。
平均峰值摄氧量为21.7±6.5 ml/kg/min，功能性有氧损害为34%±17%。功能性有氧损害与峰值体循环血管阻力呈正相关（p<0.01，r = 0.55），与峰值心脏指数呈负相关（r = -0.62），与峰值体循环动静脉氧差呈负相关（r = -0.66）。功能性有氧损害与心脏病病程之间存在弱相关性（r = 0.35，p<0.01），但与心力衰竭的病因无关。功能性有氧损害与供体年龄、总缺血时间、移植后时间、受体年龄以及静息和运动时左右心室充盈压之间均无相关性。
这些结果表明，心脏移植受者运动能力下降部分归因于外周血管阻力增加以及可能由于骨骼肌萎缩导致的氧摄取减少。这些因素可能是长期心脏病、失健或环孢素和泼尼松作用所致的不可逆变化的结果。
