Gwirtz P A, Franklin D, Mass H J
Am J Physiol. 1986 Sep;251(3 Pt 2):H490-5. doi: 10.1152/ajpheart.1986.251.3.H490.
The sympathetic innervation of the left ventricle provides a potential mechanism for modulation of synchrony of myocardial contraction. Dogs were instrumented to measure left ventricular pressure and segment length in the posterior region of the left ventricle perfused by the circumflex artery (PSL) and in an anterior region perfused by the anterior descending artery (ASL). Norepinephrine (NE) was injected into the circumflex artery using an indwelling catheter in bolus doses sufficient to produce no direct systemic effects. Intracoronary injection of NE resulted in significant increases in percent segment shortening and mean shortening velocity in the PSL. Duration of shortening in the PSL was significantly reduced. Percent shortening, velocity of shortening, and shortening duration in the ASL were unchanged. While there was no change in left ventricular systolic pressure, +dP/dtmax and -dP/dt min increased with intracoronary NE. These results demonstrate alterations in the synchrony of myocardial contraction following regional myocardial stimulation with intracoronary injections of NE at doses within the expected physiological range and suggest that activation of localized sympathetic neural pathways may result in problems involving mechanical performance of the heart.
左心室的交感神经支配为调节心肌收缩同步性提供了一种潜在机制。对犬进行仪器植入，以测量在由回旋支动脉灌注的左心室后壁区域（PSL）以及由前降支动脉灌注的前壁区域（ASL）的左心室压力和节段长度。使用留置导管以足以不产生直接全身效应的大剂量将去甲肾上腺素（NE）注入回旋支动脉。冠状动脉内注射NE导致PSL节段缩短百分比和平均缩短速度显著增加。PSL的缩短持续时间显著缩短。ASL的缩短百分比、缩短速度和缩短持续时间均未改变。虽然左心室收缩压没有变化，但冠状动脉内注射NE后，+dP/dtmax和 -dP/dt min增加。这些结果表明，在预期生理范围内冠状动脉内注射NE进行局部心肌刺激后，心肌收缩同步性发生了改变，并提示局部交感神经通路的激活可能导致涉及心脏机械性能的问题。
