Effects of 1-epinephrine on hemodynamics and cardiac function in coronary disease: dose-response studies.

To assess the effects of elevated epinephrine levels on cardiovascular performance in patients with coronary artery disease (CAD), epinephrine was infused intravenously into eight patients with normal coronary anatomy and 22 patients with CAD at dose rates of 0.06, 0.12, 0.18, and 0.24 micrograms/kg/min. Hemodynamic responses to epinephrine were not significantly different between the two groups. However, contractility increased significantly more (P less than 0.05) and end-systolic volume decreased significantly more (P less than 0.025) in normal subjects than in those with CAD. Plasma norepinephrine concentrations increased significantly (P less than 0.05) at 0.24 micrograms/kg/min epinephrine, indicating activation of sympathetic nervous system. Epinephrine ischemic thresholds ranged from 652 to 3362 pg/ml. Patients with CAD compared with normal subjects had more frequent ventricular arrhythmias (55% vs. 25%), chest pain (50% vs. 13%), and ischemic ECG changes (73% vs. 13%). These results indicate that although epinephrine induced myocardial ischemia in CAD, hemodynamics and ventricular pump function were maintained.