Atrial Natriuretic Peptide Levels in Patients with Acute Myocardial Infarction

Plasma atrial natriuretic peptide (ANP) levels were measured in 17 patients with acute myocardial infarction and in 10 healthy subjects with the radioimmunoassay method using standard kit procedure. Plasma was sampled at about the 12th hour of infarction. Those with clinical evidence of congestive heart failure at the time of plasma sampling or those with a history of hypertension were excluded. There were significant increases in the plasma ANp levels in patients with acute myocardial infarction (22.2±187 pg/ml) as compared with the controls (48±21 pg/ml) (p<0.01). ANP levels were significantly higher in patients with inferior myocardial infarcction (303 pg/ml) than in the others. Low ANP levels were found in the 7 patients who recieved thrombolytic therapy (188 pg/ml) (91 vs 317 pg/ml, p<0.01). Increasing plasma ANP levels in acute myocardial infarction presumably either depend on myocardial necrosis of on myocardial dysfunction caused by myocardial damage or both of them.