Cerebral Vasomotor Reactivity Impairment in Resistant And Non-Resistant Hypertension: The Role Of The Autonomic Nervous System.

Abstract

Abstract Purpose: Hypertension reduces the ability of the vessel wall to constrict or dilate in response to one of many possible stimuli. Cardiovascular autonomic impairment contributes to the development of hypertension and it can influence cerebral vasomotor reactivity. Little is known about the effect of resistant hypertension. This study aims to analyze the role of sympathovagal imbalance in a cohort of patients with resistant (RH) and non-resistant hypertension (NRH) and its influence on cerebral vasomotor reactivity. Methods: Forty consecutive hypertension patients, 20 with NRH and 20 with RH, underwenttime-domain heart rate variability analysis and transcranial color-coded Doppler at rest and during breath-holding maneuver to evaluate cerebral vasomotor reactivity. Results: Hypertensive individuals presented statistically significant reduction of Breath Holding Index (BHI) and time-domain parameters (SDNN and SDANN) in comparison to the control group (BHI control group 1.32 ± 0.41 vs hypertensive patients 0.92 ± 0.65; p=0,018; SDNN control group 137.87± 27.5 vs hypertensive 108.44± 26.48; p <0.0001; SDANN control group 125.76± 24.96 vs hypertensive 87.65± 20.63; p<0.0001). RH patients presented a significant reduction in BHI (NRH group BHI 1.15 ± 0.65 vs RH group BHI 0.70 ± 0.58; p=0.027) and HRV parameters (SDNN in NRH group 118.48 ± 26.01 vs RH group 96.41 ± 23.47; p=0.015; SDANN in NRH group 95.09 ± 22.12 vs RH 80.21 ± 16.36; p=0.021). Conclusions: Our results show that RH is associated with impairment of sympathovagal balance and cerebral vasomotor reactivity impairment. Autonomic dysfunction could be a concurrent cause of cerebral vasomotor reactivity impairment.