Urinary catecholamine excretion in myocardial infarction.

The catecholamine excretion rates in urine were studied in three groups of patients with acute myocardial infarction. Group I patients had no complications. Group II patients had minor complications. In groups I and II urine was obtained during the first night of the patient's admission. Group III patients had major complications, and urine was collected during one episode of complications. Catecholamines were measured by spectrophotofluorometric assay using the trihydroxyindole method. A lack of elevation in basal catecholamine excretion in patients without complications and an elevated catecholamine excretion in those with complications suggest that myocardial necrosis or ischemia per se is not responsible for increased catecholamine excretion and that the increase in catecholamine excretion may reflect the presence of complicating factors. Recurrent or persisting chest pain, pulmonary congestion or edema, and ventricular arrhythmias were almost always associated with elevated catecholamine excretion. Although in some cases a causal relationship of these complications with observed increase in catecholamine excretion is suggested, further study is required for a definitive conclusion.