The effects of isoproterenol and dopamine on regional myocardial blood flow after stenosis of circumflex coronary artery
McClenathan, J.H.; Guyton, R.A.; Breyer, R.H.; Newman, G.E.; Michaelis, L.L.
Journal of Thoracic and Cardiovascular Surgery 73(3): 431-435
1977
ISSN/ISBN: 0022-5223 PMID: 839834 Document Number: 115466
The effects of isoproterenol and dopamine on regional myocardial blood flow were studied in 10 open-chest dogs after acute stenosis of the proximal circumflex coronary artery. Blood flow was determined by the radioactive microsphere technique. Isoproterenol led to a homogenous increase in blood flow in the normal myocardium. In the myocardium with compromised coronary blood flow, isoproterenol led to a relative subendocardial ischemia. This occurred despite increased aortic flow and peak left ventricular dp/dt. Dopamine also increased aortic flow and peak left ventricular dp/dt, but it did not cause regional myocardial ischemia. The findings suggest that dopamine is the preferable inotropic agent in managing low cardiac output in patients with significant coronary artery disease.