Cardiovascular down‐regulation in essential hypotension: Relationships with autonomic control and sleep

Abstract

In this work, we aimed to clarify the autonomic involvement in the cardiovascular down-regulation in essential hypotension. The relationships between cardiovascular response and sleep quality were also examined. Thirteen female hypotensives and 13 female normotensives performed a stress task followed by polysomnography. Measures derived from blood pressure monitoring, impedance cardiography, and heart rate variability were collected. Hypotensives exhibited lower cardiovascular and autonomic activation than controls during the task. While a better sleep quality (i.e., higher sleep efficiency and lower nocturnal wakefulness) correlated with a reduced reactivity in normotensives, the opposite pattern occurred in hypotensives. The results suggest that a blunted response in both autonomic branches underlies the cardiovascular hypoactivation in hypotension. Further, good sleep seems to be associated with optimal levels of physiological reactivity.

Cerebral blood flow modulations during antisaccade preparation in chronic hypotension

“…In contrast to sympathetic control, vagal activation and deactivation can produce heart rate fluctuations within this relatively fast time scale (Berntson, Quigley, Norman, & Lozano, ). Both the smaller heart rate deceleration in hypotensive participants and the restriction of the initial heart rate increase in the antisaccade condition compared to the normotensive group are in line with previous findings of reduced cardiovascular reactivity in chronic hypotension (Covassin, de Zambotti, Cellini, Sarlo, & Stegagno, ; Duschek et al, ; Duschek, Hoffmann, Montoro, & Reyes del Paso, ).…”

“…This hypothesis has been confirmed by effects of sympathomimetic and sympatholytic drugs: while the noradrenergic alpha‐receptor agonist clonidine increases peak velocity, alpha and beta antagonists reduce it (Galley, ; Glue, White, Wilson, Ball, & Nutt, ). Autonomic dysregulation is substantially involved in the genesis of chronic hypotension, where reduced sympathetic tone appears to play a key role (Covassin, de Zambotti, Cellini, Sarlo, & Stegagno, ; Duschek, Dietel, Schandry, & Reyes del Paso, ). Various studies have demonstrated diminished sympathetic cardiac outflow in hypotension expressed as lower contractility and stroke volume and longer pre‐ejection period (Covassin, Zambotti, Cellini, Sarlo, & Stegagno, ; De Zambotti et al, ; Duschek et al, ; Duschek et al, ).…”

“…Autonomic dysregulation is substantially involved in the genesis of chronic hypotension, where reduced sympathetic tone appears to play a key role (Covassin, de Zambotti, Cellini, Sarlo, & Stegagno, ; Duschek, Dietel, Schandry, & Reyes del Paso, ). Various studies have demonstrated diminished sympathetic cardiac outflow in hypotension expressed as lower contractility and stroke volume and longer pre‐ejection period (Covassin, Zambotti, Cellini, Sarlo, & Stegagno, ; De Zambotti et al, ; Duschek et al, ; Duschek et al, ). In addition, diminished electrodermal activity (EDA) has been reported in hypotension, in terms of reduced tonic EDA and a lower rate of spontaneous EDA fluctuations (Fredrikson et al, ; Richter‐Heinrich, Borys, Sprung, & Läuter, ).…”

“…A limitation of the study pertains to the recruitment of the hypotensive sample according to WHO (1978) criteria (i.e., systolic blood pressure below 100 mmHg in women and 110 mmHg in men), which are relatively lenient (cf. Covassin et al, 2012Covassin et al, , 2013. Although these criteria are still widely accepted, more recently proposed definitions include lower systolic cutoff values and also take into account the diastolic value.…”

Reduced cerebral and cardiovascular hemodynamics during sustained affective stimulation in young women with chronic low blood pressure

“…Physiological correlates of chronic hypotension include reduced body weight, creatinine and hemoglobin [4], cortical activation [5,6], cerebral perfusion [7][8][9][10], body temperature [4], as well as generalized day-and night-time cardiovascular down-regulation [11][12][13][14]. Moreover, several studies revealed that hypotensives suffer from cognitive difficulties, mainly in the attention and memory domains [5,6,10,[15][16][17].…”