Elgodipine's Cardiovascular Impact: A Comparative Study of Intravenous and Intra-coronary Delivery in Pigs

Elgodipine, a phenyldihydropyridine, was administered to anesthetized pigs through intravenous and intracoronary routes to evaluate its effects on cardiovascular functions. The intravenous application led to a reduction in arterial blood pressure and systemic vascular resistance without impacting heart rate or left ventricular function. Even at the lowest dose, no significant negative inotropic effects were observed, but at higher doses, there was a notable decrease in left ventricular function parameters. Intracoronary infusions confirmed the drug's negative inotropic properties at certain doses, while not affecting heart rate or left ventricular filling pressure.

The drug maintained transmural myocardial blood flow during intravenous infusion, with vasodilation being more pronounced in the subepicardial layers. The decrease in the normalized subendocardial/subepicardial blood flow ratio was not due to arterial blood pressure reduction. Myocardial oxygen consumption was reduced with both routes of administration, with hypotension being the main factor for intravenous and the drug's negative inotropic effects for intracoronary.

Elgodipine also induced a redistribution of blood flow favoring nutritional flow over arteriovenous anastomotic flow. At lower infusion rates, the decrease in AVA flow was attributed to arterial blood pressure reduction, but at higher rates, increased resistance also contributed. Skeletal muscles experienced the most benefit from the increased nutritional blood flow, though not uniformly across all muscle groups. Renal vascular bed vasodilation varied between cortex layers, and at the highest infusion rate, blood flow to vital brain regions was maintained, while other organs like adrenals and spleen showed decreased blood flow.

The systemic and coronary vasodilatory effects of elgodipine without negative inotropic or chronotropic effects suggest its potential use in treating hypertension, myocardial ischemia, and possibly moderate chronic heart failure, warranting further research.