Weiss R, Knight B P, Bahu M, Zivin A, Souza J, Goyal R, Daoud E, Man K C, Strickberger S A, Halter J B, Morady F
Department of Internal Medicine, University of Michigan and the Veteran Administration Medical Center, Ann Arbor, USA.
Am Heart J. 1998 Jun;135(6 Pt 1):945-51. doi: 10.1016/s0002-8703(98)70058-4.
The electrophysiologic effects of norepinephrine (NE) in human beings have not been previously described.
The electrophysiologic effects of NE infused at a rate of 25 ng/kg/min were determined in 21 patients with a mean age of 41 +/- 11 years and without structural heart disease who underwent an electrophysiology procedure. In a subgroup of 10 patients electrophysiologic parameters were measured at baseline, after the infusion of NE, and after administration of beta-blockade while in continuous NE infusion.
The baseline NE plasma concentration of 298 +/- 153 pg/ml increased to 708 +/- 419 pg/ml after the infusion of NE. NE significantly increased the mean blood pressure, sinus cycle length, corrected sinus node recovery time, ventriculoatrial block cycle length, and the atrial and ventricular effective refractory periods. In a subset of 10 patients 0.2 mg/kg propranolol administered during continued infusion of NE resulted in a further increase in sinus cycle length, atrial-His interval, and ventricular refractoriness.
A physiologic elevation in the plasma NE concentration results in a depression of sinus node function and atrioventricular conduction and in prolongation of atrial and ventricular refractoriness. Some of NE's effects are partially offset by beta-adrenergic stimulation.
去甲肾上腺素（NE）对人体的电生理作用此前尚未见描述。
对21例平均年龄为41±11岁且无结构性心脏病的患者进行电生理检查，测定以25 ng/kg/min的速率输注NE时的电生理作用。在10例患者的亚组中，在基线、输注NE后以及在持续输注NE期间给予β受体阻滞剂后测量电生理参数。
输注NE后，NE血浆基线浓度从298±153 pg/ml增至708±419 pg/ml。NE显著提高平均血压、窦性周期长度、校正窦房结恢复时间、室房传导阻滞周期长度以及心房和心室有效不应期。在10例患者的一个亚组中，在持续输注NE期间给予0.2 mg/kg普萘洛尔导致窦性周期长度、心房 - 希氏束间期和心室不应期进一步增加。
血浆NE浓度的生理性升高导致窦房结功能和房室传导受抑制，并使心房和心室不应期延长。NE的某些作用可被β肾上腺素能刺激部分抵消。
