[The role of the sympathoadrenal and opioid systems in the pathogenesis of "silent" myocardial ischemia in ischemic heart disease].

In a study of 114 patients with ischemic heart disease (IHD) a relatedness has been found out of frequency and duration of "silent" ischemia of the myocardium to the degree of severity of atherosclerotic affection of the vascular bed and aggravation of IHD clinical symptomatology, with the activity of the opioid system tending to decline, catecholamines concentration being on the increase. It is beta-endorphin and leucine-enkephalin that have an important part to play in the regulation of algesthesia in IHD patients, the plasma content of which substances gets appreciably higher in exercise-induced painless ischemia. A change in the opioid-adrenosympathetic equilibrium is considered to be related to features of IHD clinical course. It is suggested that maintenance of the above two systems dynamic equilibrium might be of adaptive, antistressor character.