Effects of trandolapril on the sympathetic tone and reactivity in systemic hypertension.

ABSTRACT

Hemodynamic and autonomic evaluations were carried out after 2-3 weeks of treatment with placebo and at the end of 4 weeks of treatment with an angiotensin converting enzyme (ACE) inhibitor, trandolapril, 2 mg/day in 18 hypertensive patients (average age, 48 +/- 2 years) of either sex. This treatment lowered the mean arterial pressure in the whole group from 112 to 105 mm Hg (p < 0.05) without significant changes in basal heart rate or norepinephrine (NE) and epinephrine plasma levels. Based on daytime ambulatory blood pressure monitoring, the patients were separated into 2 equal groups of 9 patients the better responders (R), with an average decrease in mean arterial pressure of 12 mm Hg, and the lesser responders (NR), with an average fall of mean arterial pressure of 2 mm Hg. Before treatment, the R group had a higher resting heart rate, a lower cardiac output (-16%), and a higher peripheral resistance (+22%) than the NR group (difference not significant). Moreover, the R group was also observed to have a 33% higher plasma NE level (p < 0.05) in the supine position, associated with a 52% higher NE response to standing (p < 0.05), and a 40% lower number of beta-adrenergic receptors on lymphocytes, suggesting a higher sympathetic tone and reactivity in that group. Following treatment with the ACE inhibitor, heart rate and plasma NE levels were not altered significantly in either group, suggesting a blunting of the baroreflex response concomitant with the lowered blood pressure, especially in the R group.(ABSTRACT TRUNCATED AT 250 WORDS)