[The protective reaction of the myocardium to ischemic damage]

The morphological and functional consequences of epinephrine-induced myocardial infarction were studied in normo- (Wistar) and hypertensive (ISIAH) rats. After experimental myocardial infarction there was an irreversible transition to the "worn-out" stage or "plastic damage" to the myocardium. Thus, myocardial hibernation in ISIAH rats anticipates and determines the development of myocardial stunning, i.e., irreversible myocardial damage, whereas in the normotensive animals, the protective effect of hibernation is fully shown. The ontogenetic features of myocardial response of ISIAH rats to hypoxia promote transformation of adaptive hibernation and stunning to maladaptive pathological changes causing hypoxic alterations.