PMID: 16620712Apr 20, 2006Paper

Regional denervation after myocardial infarction and its effect on ventricular repolarization

Zhonghua yi xue za zhi
Jing-jie LiYong-lin Huang

Abstract

To investigate whether myocardial infarction (MI) causes heterogeneity of sympathetic innervation and to evaluate the effects of sympathetic stimulation on myocardial repolarization in the regions of denervation after MI. Fourteen dogs were randomly divided into 2 equal groups: MI Group, undergoing ligation of the left anterior descending coronary artery, and Control Group, undergoing sham operation. Four weeks later thoracotomy was performed for the second time, the effective refractory period (ERP) of the non-infarcted myocardium at the base of heart proximal to the infarcted myocardium and the ERP of the non-infarcted myocardium at the cardiac apex distal to the infarcted myocardium by S(1)S(2) programmed stimulation. Then the left satellite ganglion was exposed, ligated, cut, and stimulated at the proximal end, and ERP was determined at the above mentioned regions again. After the ERP measurement the heart was taken out to undergo immunohistochemistry to observe the distribution of tyrosine hydroxylase (TH) positive nerve fibers. The ERP of the non-infarcted myocardium at the base of heart proximal to the infarcted myocardium was not significantly different from that of the non-infarcted myocardium at the cardiac apex dista...Continue Reading

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