MECHANISM OF PROLONGATION OF R-R INTERVAL WITH ELECTRICAL STIMULATION OF CAROTID-SINUS NERVES IN MAN
MECHANISM OF PROLONGATION OF R-R INTERVAL WITH ELECTRICAL STIMULATION OF CAROTID-SINUS NERVES IN MAN
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DOI：
10.1161/01.res.30.1.131
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发表时间：
1972-01-01
影响因子：
20.1
通讯作者：
FLETCHER, GF
中科院分区：
文献类型：
--
作者：
ECKBERG, DL;BRAUNWALD, E;FLETCHER, GF
为了阐明刺激颈动脉窦神经延长R-R间期的机制，我们研究了8例患者在不同程度的背景自主神经活动和不同类型的传出自主神经阻断下激活植入式颈动脉窦神经刺激器的效果。静脉注射心得安0.20 mg/kg诱导β受体阻断，静脉注射阿托品0.04 mg/kg诱导副交感神经阻断。仰卧位时，自主神经阻断药物前刺激颈动脉窦神经的R-R间期平均延长为269±56 msec，心得安（NS）后延长为442±214 msec，心得安和阿托品后延长为44±13 msec （P< 0.025）。站立姿势也发生了类似的变化。在适度的跑步机运动中，刺激颈动脉窦神经仅在阻断药物前延长R-R间期40±30毫秒，在心得安后延长62±19毫秒，在心得安和阿托品后延长40±30毫秒。由此得出结论，刺激颈动脉窦神经产生的R-R间隔的延长是继发于副交感神经活动的增强，而这种反应在勃起运动期间的衰减似乎是由于副交感神经系统对压力感受器刺激的反应性的中央介导的减少。
To elucidate the mechanism by which stimulation of the carotid sinus nerves prolongs the R-R interval, the effects of activating an implanted carotid sinus nerve stimulator were studied in eight patients at varying levels of background autonomic activity and with varying types of efferent autonomic blockade. Beta-receptor blockade was induced with intravenous propranolol, 0.20 mg/kg, and parasympathetic blockade with intravenous atropine, 0.04 mg/kg. In the supine position, average prolongation of the R-R interval due to stimulation of the carotid sinus nerves was 269 ± 56 msec prior to autonomic blocking drugs, 442 ± 214 msec after propranolol (NS), and 44 ± 13 msec after propranolol and atropine (P< 0.025). Comparable changes were produced in the standing position. With moderate treadmill exercise, stimulation of the carotid sinus nerves prolonged the R-R interval by only 40 ± 30 msec prior to blocking drugs, 62 ± 19 msec after propranolol, and 40 ± 30 msec after propranolol and atropine. It is concluded that the prolongation of the R-R interval produced by stimulation of the carotid sinus nerves is secondary to augmented parasympathetic activity, and the attenuation of this response during erect exercise appears to be due to a centrally mediated reduction in the responsiveness of the parasympathetic nervous system to baroreceptor stimuli.