The mid frequency component (MFC = 66-128 mHz) of blood pressure is an index of sympathetic vascular control. To investigate the effect of bisoprolol (B) and ramipril (R) treatment (TT) on the short-term variability of systolic blood pressure (SBP) diastolic blood pressure (DPB) and heart rate (HR) reactivity during mental stress, we studied 54 mild essential untreated hypertensive patients (24 men, 45 +/- 9.6 years, BP > 160/90 mmHg after a 15-days placebo run-in period) who were randomly assigned to double blind treatment (B: 10 mg/day: n = 28 and R: 5 mg/day: n = 26). A Stroop Word Color Conflict Test (SWCCT) was performed before and after 2 months of treatment. Hemodynamic parameters (BP and HR) were measured by a non invasive device (Finapres 2300E, Ohmeda-Maurepas) and underwent spectral analysis (SBP: mmHg.Hz-1/2, HR: beats/min.Hz-1/2, Anapres 1.2, Notocord-Orgametrie Systems, Igny-Lille) at rest and during SWCCT. The sympathetic vascular activity was assessed by calculating the area of the mid-frequency component (MFC = 66-128 Hz).
RESULTS:[table: see text]
The absolute variations in sympathetic activity during SWCCT as demonstrated by analysis of MFC of SBP and HR is not affected by chronic ramipril treatment, whereas bisoprolol attenuates sympathetic reactivity during SWCCT.