Methylprednisolone treatment in acute myocardial infarction. Effect on regional and global myocardial function.
The effects of methylprednisolong treatment on acute myocardial ischemia were studied in nine closed chest dogs. After 1 hour of proximal occlusion of the left anterior descending coronary artery, an intravenous bolus injection (50 mg/kg body weight) of methylprednisolone was administered and its effects studied during an additional 2 hours of occlusion. After 2 hours of treatment the following significant mean alterations from levels after 1 hour of occlusion were noted: an increase of 16.7% in heart rate and decreases of 23% in left ventricular end-diastolic pressure, 32% in stroke volume, 14% in cardiac output and 37% in stroke work. Peak systolic pressure, maximal rate of rise of left ventricular pressure (dP/dt), left ventricular end-diastolic volume, systemic vascular resistance and coronary sinus blood flow changed less than 10%. Ejection fraction and regional cardiac wall motion were not improved. Metabolic dysfunction of the coronary-occluded myocardium, revealed by regional lactate as well as potassium derangements, persisted throughout the 2 hour treatment period. Comparison of these results with equivalent data from an untreated series of nine dogs with 3 hours of occlusion demonstrated no improvement in the treated series. Methylprednistone failed to restore regional cardiac metabolic and mechanical function, and treatment was associated with a further rise in S-T segment elevations. Administration of methylprednisolone after 1 hour of proximal left anterior descending coronary occlusion apparently does not reverse cardiac dysfunction in the first 2 hours of treatment.
D000208:Acute Disease; D000818:Animals; D003327:Coronary Disease / Q000188:drug therapy; D003331:Coronary Vessels / Q000187:drug effects; D004285:Dogs; D004562:Electrocardiography; D006321:Heart / Q000503:physiopathology*; D006439:Hemodynamics / Q000187:drug effects; D007773:Lactates / Q000378:metabolism; D008775:Methylprednisolone / Q000494:pharmacology / Q000627:therapeutic use*; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism; D010100:Oxygen / Q000097:blood; D011188:Potassium / Q000378:metabolism
D007773:Lactates; D011188:Potassium; D010100:Oxygen; D008775:Methylprednisolone