[Morpho-functional changes in the heart of sympathectomized animals during acute myocardial ischemia]

Experiments on 142 Wistar male rats were made to study the effect of chemical desympathization on functional and structural changes in the heart during acute myocardial ischemia produced by ligation of the anterior descending branch of the left coronary artery. In the desympathized rats with acute myocardial ischemia, arrhythmias occurred in a less number of cases and were less severe. One day after the artery occlusion the decrease in myocardial contractility was less considerable than in the control animals. More rapid localization of the ischemic focus was found to occur in the desympathized myocardium. The pattern of changes in lipid metabolism in the desympathized and in normally innervated heart was different: in the desympathized heart accumulation of neutral fat was observed while in the normal one acid lipids. It is concluded that different pattern of functional and structural changes in the myocardium of the normal and desympathized animal is determined by the status of the heart sympathetic nervous system, namely by a decrease or elimination of the pathogenic action on the myocardium of noradrenaline which is released in high concentrations because of sharp stimulation of the sympathoadrenal system.