Givertz M M, Hartley L H, Colucci W S
Cardiomyopathy Program, Brigham and Women's Hospital, Boston, Mass., USA.
Circulation. 1997 Jul 1;96(1):232-7. doi: 10.1161/01.cir.96.1.232.
Peak exercise capacity improves early after orthotopic cardiac transplantation. However, the physiological response to exercise remains abnormal, with a reduced rate of heart rate (HR) rise and reductions in peak exercise HR and the increment in HR from rest to peak exercise. This chronotropic incompetence is due in large part to cardiac denervation. If reinnervation occurs after transplantation, it might result in an improvement in both chronotropic responsiveness and maximal exercise capacity. We therefore hypothesized that the chronotropic response to exercise and maximal exercise capacity would improve with time after transplantation.
Peak symptom-limited cardiopulmonary exercise tests performed in 57 clinically stable cardiac transplant recipients (mean age, 45 +/- 2 years) serially for up to 5 years after transplantation and in 33 control subjects without heart disease were analyzed retrospectively. Pretransplantation exercise tests were also performed in 41 patients an average of 4.7 +/- 0.6 months before transplantation. At 1 year after transplantation, peak oxygen consumption was 16.6 +/- 0.9 mL.kg-1.min-1, reflecting a 43% increase versus pretransplantation. Nevertheless, compared with control subjects, maximal exercise capacity and the HR response to exercise were subnormal in transplant recipients. There were no further increases in peak exercise capacity, peak exercise HR, or the peak increment in HR with exercise up to 5 years after transplantation.
One year after cardiac transplantation, peak exercise capacity and chronotropic responsiveness are subnormal. There is no further improvement in peak exercise capacity or chronotropic responsiveness as late as 5 years after transplantation. These data indicate that with regard to chronotropic responsiveness, functionally significant cardiac reinnervation does not occur between the first and fifth years after transplantation.
原位心脏移植术后早期运动能力峰值有所提高。然而，运动时的生理反应仍不正常，心率（HR）上升速率降低，运动峰值心率及静息至运动峰值时心率的增加值均降低。这种变时性功能不全在很大程度上是由于心脏去神经支配所致。如果移植后发生再神经支配，可能会导致变时性反应性和最大运动能力均得到改善。因此，我们假设移植后随着时间推移，运动时的变时性反应和最大运动能力会有所改善。
对57例临床稳定的心脏移植受者（平均年龄45±2岁）在移植后长达5年的时间里连续进行的症状限制心肺运动试验峰值进行回顾性分析，并与33例无心脏病的对照受试者进行比较。41例患者在移植前平均4.7±0.6个月也进行了运动试验。移植后1年，峰值耗氧量为16.6±0.9 mL·kg-1·min-1，较移植前增加了43%。然而，与对照受试者相比，移植受者的最大运动能力和运动时的心率反应仍低于正常水平。移植后长达5年，运动峰值能力、运动峰值心率或运动时心率的峰值增加值均未进一步增加。
心脏移植后1年，运动峰值能力和变时性反应低于正常水平。移植后长达5年，运动峰值能力或变时性反应均未进一步改善。这些数据表明，在变时性反应方面，移植后第1年至第5年未发生具有功能意义的心脏再神经支配。
