VAGALLY MEDIATED HEART-RATE RECOVERY AFTER EXERCISE IS ACCELERATED IN ATHLETES BUT BLUNTED IN PATIENTS WITH CHRONIC HEART-FAILURE
VAGALLY MEDIATED HEART-RATE RECOVERY AFTER EXERCISE IS ACCELERATED IN ATHLETES BUT BLUNTED IN PATIENTS WITH CHRONIC HEART-FAILURE
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DOI：
10.1016/0735-1097(94)90150-3
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发表时间：
1994-11-15
影响因子：
24
通讯作者：
KAMADA, T
中科院分区：
文献类型：
--
作者：
IMAI, K;SATO, H;KAMADA, T
目标.通过分析运动后心率衰减，对慢性心力衰竭患者和训练有素的运动员运动后迷走神经介导的心率恢复进行评估。迷走神经再激活是运动后心脏减速的重要机制。然而，在病理条件下，这种机制的改变还没有被表征，因为缺乏一个特定的指标。为了找到心率恢复的迷走神经介导成分，在六个运动水平下获得了8名正常志愿者运动后前30 s（T-30）和前120 s（T-120）的逐拍心率衰减的时间常数：1）最大运动时，2）无氧阈值时，3）普萘洛尔给药时无氧阈值时，4）阿托品给药时无氧阈值时，5）在无氧阈值下同时给予两种药物，和6）在无氧阈值的50%下。为探讨心力衰竭和耐力训练对迷走神经介导的心率恢复的影响，测定了20例慢性心力衰竭患者和9名越野滑雪运动员的T-30和T-120。在正常志愿者中，T-30和T-120显着延长阿托品给药，表明这两个时间常数介导的迷走神经再激活。此外，T-30几乎不受运动强度和交感神经阻滞的影响，而T-120则受交感神经活动和运动负荷的影响。这些结果表明，T-30主要由迷走神经再激活介导，不依赖于交感神经和牵拉，运动员T-30显著小于相应年龄匹配的正常对照组（p <0.01），慢性心力衰竭患者T-30显著大于相应年龄匹配的正常对照组（p < 0.01）。T-30值可作为迷走神经介导心率恢复的特异性指标。运动后迷走神经介导的心率恢复在训练有素的运动员中加速，但在慢性心力衰竭患者中减弱。
Objectives. Vagally mediated heart rate recovery after exercise was assessed in patients with chronic heart failure and in well trained athletes by analyzing the postexercise heart rate decay.Background. Vagal reactivation is an important cardiac deceleration mechanism after exercise. However, alterations of this mechanism under pathologic conditions have not been characterized because of the lack of a specific index.Methods. To find a vagally mediated component of heart rate recovery, the time constants of the beat-by-beat heart rate decay for the first 30 s (T-30) and the first 120 s (T-120) after exercise were obtained at six levels of exercise in eight normal volunteers: 1) at maximal exercise, 2) at anaerobic threshold, 3) at anaerobic threshold with propranolol administration, 4) at anaerobic threshold with atropine administration, 5) at anaerobic threshold with concomitant administration of both drugs, and 6) at 50% of anaerobic threshold. To investigate the effects of heart failure and endurance training on vagally mediated heart rate recovery, T-30 and T-120 at anaerobic threshold were obtained in 20 patients with chronic heart failure and in 9 cross country skiers.Results. In normal volunteers, T-30 and T-120 were markedly prolonged by atropine administration, indicating that both time constants are mediated by vagal reactivation. Moreover, T-30 was almost independent of the exercise intensity and sympathetic blockade, whereas T-120 was affected by sympathetic nerve activity and exercise work load. These results indicate that T-30 is mediated primarily by vagal reactivation, independent of sympathetic with drawal, and is significantly smaller in athletes (p < 0.01) and significantly larger in patients with chronic heart failure (p < 0.01) than that in respective age-matched normal control subjects.Conclusions. The T-30 value could be a specific index for vagally mediated heart rate recovery. Vagally mediated heart rate recovery after exercise is accelerated in well trained athletes but blunted in patients with chronic heart failure.