This study investigated arterial and coronary venous catecholamine concentrations in patients undergoing either elective coronary angioplasty (PTCA) or direct PTCA for acute myocardial infarction. We included 17 patients with stenoses of the left anterior descending coronary artery (LAD) and 10 patients with acute anterior myocardial infarction (AMI) undergoing PTCA. During the initial balloon dilatation arterial and coronary venous plasma concentrations of norepinephrine and epinephrine were determined. In elective PTCA, coronary occlusion (2 min) resulted in a transient increase of arterial concentrations of norepinephrine (2.04 +/- 0.30 vs. 1.26 +/- 0.13 nmol/L before dilatation) and epinephrine (0.52 +/- 0.08 vs. 0.34 +/- 0.04 nmol/L) in the first minute of reperfusion, whereas coronary venous concentrations of catecholamines were not changed after dilatation. Among the 10 patients with AMI, immediate reperfusion of the LAD (TIMI grade 3) was achieved in 6 patients. In these patients, baseline arterial concentrations for norepinephrine (3.91 +/- 1.16 nmol/L) and epinephrine (4.68 +/- 2.07 nmol/L) were elevated and no transcardiac gradient for catecholamines was found. In the first minute after successful reopening of the LAD we detected a distinct rise of the transcardiac norepinephrine gradient from -0.10 +/- 0.53 to 85.02 +/- 24.64 nmol/L, which declined in the fifth minute of reperfusion of 4.36 +/- 2.30 nmol/L. Conversely, venous epinephrine and arterial concentrations for both catecholamines remained unchanged within the observation period. In the four patients with incomplete (TIMI 0-2) reopening of the LAD, we found no cardiac washout of norepinephrine. In summary, a transient rise of systemic catecholamines, but no cardiac release of norepinephrine was observed in patients after brief coronary occlusion. Conversely, a massive washout of norepinephrine from the infarcted myocardium occurred during AMI.