Regional myocardial perfusion and wall thickness and arteriovenous shunting after ergotamine administration to pigs with a fixed coronary stenosis

Abstract

The hemodynamic effects of antimigraine drug ergotamine, which is considered contraindicated in patients with coronary artery disease, were studied in pigs with a normal myocardial circulation (doses of 8, 16, and 32 micrograms/kg, i.v.) or with acute coronary stenosis (8 micrograms/kg). In both groups of animals, ergotamine decreased heart rate, cardiac output, and arteriovenous anastomotic blood flow while increasing aortic blood pressure and systemic vascular resistance. No effects on total ventricular blood flow and its distribution within the myocardium were found in normal animals. In animals with a clamp on the left anterior descending coronary artery (LAD), the blood flow to the LAD-perfused area was reduced from 1.10 +/- 0.16 to 0.67 +/- 0.05 cm3/min/g. The endocardium was affected more than the epicardium and the endo/epi flow ratio decreased from 1.18 +/- 0.05 to 0.74 +/- 0.07. Ergotamine increased the blood flow to the ischemic zone towards normal values, and the endo/epi flow ratio to 1.05 +/- 0.21. However, myocardial wall thickness parameters, which showed functional deterioration during ischemia, did not change after ergotamine. The present study provides no clear support for cardiovascular contraindications to ergotamine administration.