ABSTRACT
Twenty patients (aged 33-60 years) with mild to moderate essential hypertension were studied to assess systolic ventricular function, diastolic ventricular function, and peripheral hemodynamic changes induced by nitrendipine during rest and effort, comparing the acute and chronic treatment phases. We used a randomized, placebo-controlled, double-blind, crossover protocol in the acute phase and a paired, placebo group controlled study, with 20 mg single oral daily dose for a 3-week treatment period (chronic phase). The cardiac and peripheral hemodynamic parameters were quantified by noninvasive radionuclides techniques. During acute treatment, peripheral hemodynamics showed a predominantly arteriolar vasodilatory effect with a significant fall in the previously elevated forearm vascular resistance values (-38%, p less than 0.01) and an important increase in forearm blood flow (+49%, p less than 0.01) without any changes in venous capacity. Simultaneously, nitrendipine produced a significant drop in total peripheral resistance (-36%, p less than 0.01), systolic blood pressure (-13%, p less than 0.01), and diastolic blood pressured (-17%, p less than 0.01). The sudden reduction in left ventricular (LV) afterload caused a reflex increase in heart rate (HR) (+12%, p less than 0.01), cardiac index (+37%, p less than 0.01), LV ejection fraction (+17%, p less than 0.01), and peak ejection rate, with an important decrease in LV end systolic volume (-30%, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)