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Calcium antagonists and left ventricular function: effects of nitrendipine in congestive heart failure
Insights
Nitrendipine, a calcium antagonist, improves left ventricular (LV) performance in patients with heart failure by reducing preload and systemic vascular resistance. This study shows favorable effects without reflex neurohumoral stimulation.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Calcium antagonists impact arterial and venous vessels, and the myocardium.
- The net effect on left ventricular (LV) performance is complex, depending on drug properties and patient's LV function.
- Arterial vasodilators may improve LV performance despite negative inotropic effects.
Purpose of the Study:
- To directly assess the effect of nitrendipine, a 1,4-dihydropyridine calcium antagonist, on LV performance.
- To evaluate the acute hemodynamic response to oral nitrendipine in patients with congestive heart failure.
Main Methods:
- Oral administration of 10 to 20 mg of nitrendipine to 8 patients with congestive heart failure.
- Hemodynamic parameters including preload, pulmonary wedge pressure, systemic vascular resistance, blood pressure, and stroke volume were measured.
- Plasma levels of norepinephrine and renin activity were assessed.
Main Results:
- Nitrendipine reduced preload, pulmonary wedge pressure, and systemic vascular resistance.
- A modest decrease in blood pressure and an increase in stroke volume were observed.
- Plasma norepinephrine levels significantly decreased, and plasma renin activity tended to decrease.
Conclusions:
- Nitrendipine favorably alters the performance of the failing left ventricle.
- The vasodilator effect of nitrendipine is not accompanied by reflex neurohumoral stimulation in these patients.
Abstract:
Calcium antagonists can affect the arterial vasculature, the venous capacitance vessels and the myocardium. The net effect of these agents on left ventricular (LV) performance depends on the interaction of effects on these 3 vascular components, and the state of LV function at the time that the drugs are administered. A calcium antagonist with profound arterial vasodilator effect might favorably influence LV performance even if it had negative inotropic properties. To demonstrate the direct effect of nitrendipine, a 1,4 dihydropyridine, on LV performance, the acute hemodynamic response to oral nitrendipine was studied in 8 patients with congestive heart failure. Administration of 10 to 20 mg of nitrendipine reduced preload, caused a decrease in both pulmonary wedge pressure and systemic vascular resistance, produced a modest decrease in blood pressure and an increase in stroke volume. In addition, plasma norepinephrine levels were significantly decreased. Plasma renin activity also tended to decrease. These data confirm that the drug can favorably alter performance of the failing left ventricle and further suggest that the vasodilator effect is not accompanied by reflex neurohumoral stimulation.