Cardiovascular effects of elgodipine in conscious pigs with a normal coronary circulation and in conscious pigs with a healed myocardial infarction.

The cardiovascular effects of the phenyldihydropyridine derivative elgodipine (0.3, 1, 3, 10, and 30 microgram/kg/min) were studied in normal conscious pigs and in pigs with chronic left ventricular dysfunction (LVD, caused by coronary artery occlusion) without and after beta-adrenoceptor blockade with propranolol (0.5 mg/kg + 0.5 mg/kg/h). In normal pigs, elgodipine increased cardiac output from 2.57 +/- 0.09 to 5.21 +/- 0.24 L/min (p less than 0.05) as a result of a doubling of the heart rate. Mean arterial blood pressure decreased from 94 +/- 2 to 76 +/- 3 mm Hg (p less than 0.05) as a result of a decrease in systemic vascular resistance. Left ventricular (LV) dP/dtmax increased (by up to 78 +/- 9%), but left ventricular end-diastolic pressure (LVEDP) remained unchanged. After propranolol administration elgodipine did not increase LV dP/dtmax, and the increase in heart rate was attenuated, resulting in a smaller increase in cardiac output (from 2.11 +/- 0.13 to 3.09 +/- 0.23 L/min, p less than 0.05), but an unchanged vasodilator response. In pigs with LVD, elgodipine increased cardiac output and LV dP/dtmax less than in normal animals, but the vasodilator response was not affected. LVEDP decreased from 14.6 +/- 1.6 to 11.7 +/- 2.5 mm Hg (p less than 0.05). In animals with LVD, propranolol caused a more severe depression of systemic hemodynamics, but did not modify the cardiovascular responses to elgodipine. Its cardiovascular profile suggests that elgodipine may not only be useful in the treatment of cardiovascular disorders for which other dihydropyridines are already in use, but also in mild chronic heart failure.