title: Detection of myocardial infarction extension or reattack by serum myoglobin radioimmunoassay.
abstract: We evaluated serum myoglobin levels in patients with acute myocardial infarction and investigated their diagnostic significance on episodic reattack on the course of acute infarction. Myoglobin was measured by radioimmunoassay, and the upper limit of normal was 50 ng/ml. Raised myoglobin levels were present in 52 of 53 patients (98%) with documented acute myocardial infarction admitted within 12 hr and in 16 of 20 patients (80%) admitted between 12 and 24 hr after the onset. Maximal values occurred 11.1 +/- 5.0 (mean +/- SD) hr and returned to the normal ranges 1.6 +/- 1.1 days after the onset. Because of its early normalization and high sensitivity to new necrosis, myoglobin might be a useful biochemical marker for diagnosis of infarct extension or reattack. Forty-seven episodic reelevations were classified into three groups (definite, probable and possible) according to the rating system indicating reattack of myocardial infarction. The incidence of definite and probable reattack or extension was 21%, and possible 19%. Reelevation of serum myoglobin occurred on an average of 5.0 days after the initial attack, within the first 3 days in 53% and on the second day in 31%. These results might suggest that an unexpectedly large cohort of myocardial infarction shows reattack in its early days of initial suffering.
mesh_terms: D000328:Adult; D000368:Aged; D001219:Aspartate Aminotransferases / Q000097:blood; D003402:Creatine Kinase / Q000097:blood; D003937:Diagnosis, Differential; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000201:enzymology; D009211:Myoglobin / Q000097:blood*; D011863:Radioimmunoassay; D012008:Recurrence
chemical_list: D009211:Myoglobin; D007770:L-Lactate Dehydrogenase; D001219:Aspartate Aminotransferases; D003402:Creatine Kinase