Singh Tajinder P, Gauvreau Kimberlee, Rhodes Jonathan, Blume Elizabeth D
Department of Cardiology, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts 02115, USA.
J Heart Lung Transplant. 2007 Dec;26(12):1306-12. doi: 10.1016/j.healun.2007.08.013. Epub 2007 Oct 26.
Cardiac autonomic innervation modulates heart rate (HR) response during and HR recovery after exercise in normal subjects. Heart transplantation results in surgical interruption of autonomic innervation. We assessed whether HR response during exercise and HR recovery after exercise in pediatric heart transplant recipients are consistent with autonomic denervation of the heart after transplant and whether they evolve over years in a manner consistent with autonomic re-innervation.
We compared HR response during and HR recovery after a maximum treadmill exercise test in 35 children (median age 13.4 years) after a median follow-up of 1 year after heart transplant with two control groups: post-operative Fontan patients (n = 31) and normal children (n = 35). We then analyzed 153 treadmill exercise tests performed serially in 45 heart transplant recipients (median 3 tests/patient) for longitudinal changes in peak HR and HR recovery after exercise.
Transplant recipients had higher body mass index, higher resting HR and significantly attenuated 1- and 3-minute HR recovery after cessation of exercise compared with both control groups (p < 0.001). In transplant recipients with serial exercise tests, peak HR increased an average of 2.0 beats/min per year after transplant (p < 0.001), percent predicted peak HR increased by 1.3% per year (p < 0.001), 1-minute HR recovery increased by 1.0 beats/min per year (p < 0.001), and 3-minute HR recovery by 2.6 beats/min per year (p < 0.001).
HR response to exercise and HR recovery after exercise in pediatric heart transplant recipients are consistent with autonomic denervation after transplant and suggestive of late autonomic re-innervation of these hearts.
在正常受试者中，心脏自主神经支配调节运动期间的心率（HR）反应以及运动后的HR恢复。心脏移植导致自主神经支配的手术中断。我们评估了小儿心脏移植受者运动期间的HR反应和运动后的HR恢复是否与移植后心脏的自主神经去支配一致，以及它们是否以与自主神经再支配一致的方式随时间演变。
我们比较了35名儿童（中位年龄13.4岁）在心脏移植术后中位随访1年后进行的最大跑步机运动试验期间的HR反应和运动后的HR恢复情况，与两个对照组进行比较：术后Fontan患者（n = 31）和正常儿童（n = 35）。然后我们分析了45名心脏移植受者（中位每人3次测试）连续进行的153次跑步机运动试验，以观察运动后峰值HR和HR恢复的纵向变化。
与两个对照组相比，移植受者的体重指数更高，静息HR更高，运动停止后1分钟和3分钟的HR恢复明显减弱（p < 0.001）。在进行连续运动试验的移植受者中，移植后峰值HR平均每年增加2.0次/分钟（p < 0.001），预测峰值HR百分比每年增加1.3%（p < 0.001），1分钟HR恢复每年增加1.0次/分钟（p < 0.001），3分钟HR恢复每年增加2.6次/分钟（p < 0.001）。
小儿心脏移植受者运动时的HR反应和运动后的HR恢复与移植后的自主神经去支配一致，并提示这些心脏后期存在自主神经再支配。
