心脏病学
等长运动
内科学
医学
左冠状动脉
乳头肌
心室压
收缩(语法)
舒张期
动脉
右冠状动脉
血流动力学
血压
心肌梗塞
冠状动脉造影
作者
J. M. Capasso,Peng Li,Xun Zhang,Piero Anversa
出处
期刊:American Journal of Physiology-heart and Circulatory Physiology
[American Physiological Society]
日期:1991-12-01
卷期号:261 (6): H1802-H1810
被引量:2
标识
DOI:10.1152/ajpheart.1991.261.6.h1802
摘要
To determine the effects of chronic coronary artery narrowing on myocardial contractile performance, nonocclusive constriction of the left coronary artery near its origin was surgically induced in rats and global cardiac hemodynamics, left and right myocardial mechanics, and the magnitude and distribution of tissue damage and interstitial fibrosis in the left ventricular wall were analyzed 1 mo later. Reductions in coronary artery luminal diameter of 55% resulted in left ventricular failure as characterized by decreases in systemic arterial pressures, systolic ventricular pressure, rise and decay in first derivative of left ventricular pressure (+/- dP/dt), and an increase in left ventricular end-diastolic pressure. Right side dysfunction was also present as documented by an elevation in right ventricular end-diastolic pressure and a reduction in -dP/dt. In vitro measurements of papillary muscle mechanics revealed a biventricular reduction in isometric developed tension and peak rates of tension rise and decay. Moreover, the kinetic parameters of isometric contraction duration, time to peak tension and time to one-half relaxation, were significantly shorter in left muscles from coronary artery-narrowed animals. Isotonically, peak muscle shortening was reduced in the left muscle, whereas time to peak shortening was prolonged in the right myocardium. In addition, the velocities of muscle shortening and relengthening were decreased in both ventricles. Foci of replacement fibrosis and diffuse interstitial fibrosis were found in the epimyocardium, midmyocardium, and endomyocardium, demonstrating that a significant amount of myocyte loss occurred throughout the left ventricular wall.(ABSTRACT TRUNCATED AT 250 WORDS)
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