Abstract: An experimental study of myocardial damage was induced in Wistar rats following noradrenaline infusion(20 ug/kg body wt/minute),for a period of 90 minutes daily for three consecutive days,the animals were killed after some minutes(acute phase),7 days(subacute phase),30-90 days(chron- ic phase),observed by histopathological,myoglobin immunohisto-chemical and ultrastructural me- thods.The results demonstrated multiple focal necrosis and myoglobin defects of myocytes,my- ofibrillar fragmentation and dissolution in the acute phase,this morphological feature simulated human cases of myocardial infarction without coronary occlusion.After acute phase,focal atrophy and scars of myocardium,active proliferaton of fi- bre(?) asts and neo-collageous fibrils infiltrated in r(?)crofic myocytes are present,this feature si rula- ted the early cardio-myopathy.