Fabio Priante

Effects of long-term nicardipine treatment on hemodynamics of large arteries in essential hypertension

SummaryThe effects of the calcium-entry blocker nicardipine on brachial hemodynamics were studied in 22 patients (18 male, 4 female) with essential hypertension, who were treated with 20 mg tid for 1 year. Compliance, characteristic impedance, vascular resistances, and tangential tension were measured before treatment and after 1, 3, and 12 months of treatment by an automatic recording from a B-mode, high-resolution, real-time scanner and pulsed Doppler velocimetry for the calculation of the flow volume. We observed statistically significant variations in compliance and impedance after 1 month (3.21±0.59 dyn−1 cm4 10−7 vs. 1.26±0.16 dyn−1 cm4 10−7 and 50.6±4.7 dyn s cm−5102 vs. 91.4 ±7.3 dyn s cm−5 102, respectively; mean±SEM; p<0.001), while tangential tension was significantly reduced after only 3 months (23.2±2.2 mmHg vs. 25.4±2.3 mmHg cm; p<0.05). The correlation between variations in mean blood pressure and in the hemodynamic parameters studied remained statistically significant throughout the study. Nicardipine improved the parameters of large-artery hemodynamics that favor a normal systolic pulse.

Changes in the haemodynamics of large arteries induced by single doses of nicardipine, enalapril, atenolol and urapidil.

SummaryHaemodynamic changes in the carotid and brachial arteries produced by single doses of four antihypertensive drugs (nicardipine, enalapril, atenolol, and urapidil) have been studied in 12 patients with essential hypertension. Measurements were performed noninvasively using a mechanographic method and B-mode pulsed Doppler ultrasonography.Within 7 h all of the drugs had caused a significant reduction in blood pressure, whereas heart rate showed a significant change only after atenolol. All the drugs produced a marked reduction in brachial pulse-wave velocity. Only nicardipine caused a significant reduction in vessel wall tension both in the carotid and brachial arteries, while brachial peripheral resistance was significantly reduced by all the drugs except atenolol. Neither atenolol nor enalapril caused any significant reduction in carotid peripheral resistance.The results show that all four antihypertensive drugs led to a beneficial increase in arterial compliance despite their different effects on peripheral resistance.

Modifications in peripheral hemodynamics and left ventricular function in hypertensives treated with nicardipine slow release

Dear Sir, Hemodynamic factors like compliance, characteristic impedance, and peripheral resistance contribute to afterload, an extremely important factor in left ventricular hypertrophy [1,2]. Against this background, we set out to evaluate the action of nicardipine in hypertension [3,4], relating changes in arterial parameters to those in the left ventricular myocardium. We studied 12 male patients (mean age 41 years, range 34-50 years) with mild to moderate essential hypertension, t reated with nicardipine slow release (40 mg twice daily). Peripheral and cardiac hemodynamic parameters were examined basally and after 1 and 6 months treatment. Blood pressure was recorded with a previously validated [5] automatic apparatus (Dinamap 845XT, Critikon, Johnson & Johnson, Tampa, FL). Hemodynamic parameters were recorded using a plethysmographic method for the measurement of pulse wave velocity (variability ± 6%). By means of a Duplex scanner (Diasonics CV 400, Diasonics, Milpitas, CA) with a 10 Mhz probe and a longitudinal power of resolution of 0.3-0.4 mm, we also measured the diameter (variability ± 4%) of the brachial and common carotid arteries, as well as volume flow (variability ± 8%). In the common carotid, diameter was always measured 2 cm from the beginning of the bulbar dilatation, to avoid any mismeasurements. At the same observation times, patients were also subjected to M-mode, two-dimensional echocardiogram and US-Doppler study of transmittal flows. Echocardiograms were analyzed by a previously described computerized system [6]. Means were compared by Students t test for paired data, with allowance for the correction of Bonferroni. Results after 1 month showed a statistically significant reduction in systolic and diastolic blood pressure (147 -3/93 ± 2 vs. 169 ± 7/106 _+ 2 mmHg, mean ± SEM, p < 0.001), which was maintained after 6 months (149 _ 3/94 +__ 2 mmHg, p < 0.001). Over the same period, heart rate showed a slight but never statistically significant increase (first month vs. basal: 69 ± 2 vs. 66 ± 3 beats/min, sixth month: 71 ± 3 beats/min, p ns). The diameter of the brachial (BAD) and common carotid arteries (CCAD), the variations in hemodynamic parameters after 1 and 6 months, and the echocardiographic results are shown in Table 1. Important findings were the improvement of peripheral hemodynamics and also the shift of mass/volume index, show-. ing an increase of the volume in relation to the mass in the left ventricle. Nicardipine SR exerts a significant effect on blood pressure [7], reducing afterload, and on the left ventricular myocardium, improving diastolic compliance and inducing a gradual reduction of hypertrophy. The balanced combination of these actions determines regression of altered left ventricular morphology and function caused by overload, normalizing ventricular performance [8]. In the heart, significant reduction of posterior wall (PWTD) and interventricular septum thickness (IVSTD) was observed, as well as favorable remodeling of the geometry with a significant increase in the end-diastolic transverse diameter of the left ventricle and shortening of its longitudinal diameter, resulting in an increase of end-diastolic volume (EDV). In addition, there was a marked improvement in diastolic function evaluated by the time of isovolumetric relaxation, the percentage contribution of rapid filling (RF/ EDV) and atrial systole to total left ventricular filling (AS/EDV), and the speed of filling (dv/dt) during diastole. When other classes of drugs are used, in the event of actual left ventricular hypertrophy, vascular