Data in humans indicate that individuals with orthostatic hypotension that are refractory to other traditional forms of therapy are responsive to selective serotonin reuptake inhibitor (SSRI) treatment. We tested the hypothesis that SSRI administration would help correct the attenuated baroreflex control of sympathetic nervous system activity in the hindlimb-unloaded (HU) rat model of cardiovas...

Earlier studies from the authors' laboratory showed that malnourishment induces alterations in the cardiovascular homeostasis increasing the basal mean arterial pressure and heart rate. In this study, the authors evaluated whether the sympathetic and parasympathetic efferent activities contribute to changes in the cardiovascular homeostasis through altered modulation of the arterial baroreflex ...

This exploratory study assessed the pattern of closed-loop baroreflex resetting using multi-logistic-curve analysis. Operating point gain and ranges of RR-interval (RRI) and systolic blood pressure (SBP) are derived to examine how these relate to sympathetic activation. Sustained low-intensity isometric handgrip exercise, with a period of post-exercise circulatory occlusion (PECO), provided a m...

Arterial baroreflex function in humans is commonly assessed through a number of laboratory tests based on quantification of the reflex responses in heart rate or blood pressure to external stimuli applied to the cardiovascular system. Evidence is available that these laboratory estimates of baroreflex sensitivity have both pathophysiological and clinical relevance. Indeed, a number of studies h...

Volatile anaesthetic agents attenuate arterial baroreflex function, while noxious stimuli may modify baroreflex-induced circulatory responses during anaesthesia. We have examined baroreflex control of heart rate during the entire course of sevoflurane anaesthesia in adult patients undergoing surgical procedures. Baroreflex sensitivity was assessed in nine healthy patients undergoing general ana...

This study investigated the effect of micropressure injection of the V1 arginine vasopressin (AVP) receptor antagonist into the area postrema on the ability of circulating AVP to augment baroreflex inhibition of renal sympathetic nerve activity (RSNA) in urethane-anesthetized rabbits. In addition, the effects of micropressure injections of AVP into the area postrema on RSNA, arterial pressure, ...

BACKGROUND This study was designed to determine cardiovagal baroreflex gain during propofol infusion and to characterize its recovery profile using the pharmacological and spontaneous sequence methods in 13 healthy volunteers without cardiovascular or autonomic disorders. METHODS After an 8- to 10-h fast and no premedication, measurements of RR intervals obtained from the electrocardiogram an...

The effects of exercise training on baroreflex control of sympathetic nerve activity in human hypertension are unknown. We hypothesized that exercise training would improve baroreflex control of muscle sympathetic nerve activity (MSNA) and heart rate (HR) in patients with hypertension and that exercise training would reduce MSNA and blood pressure (BP) in hypertensive patients. Twenty never-tre...

OBJECTIVE To examine the relation between cardiac autonomic tone, assessed by baroreflex sensitivity and heart rate variability, and left ventricular function, arrhythmias on Holter monitoring, and clinical variables in patients with idiopathic dilated cardiomyopathy. DESIGN A prospective observational study. PATIENTS 160 patients with idiopathic dilated cardiomyopathy and preserved sinus r...

The purpose of this study was to determine if arterial baroreflex control of sympathetic nerve traffic is impaired in heart failure. We recorded renal nerve activity during changes in arterial pressure while simultaneously recording from aortic baroreceptor afferent fibers in 10 dogs with heart failure induced by rapid ventricular pacing and in 10 sham animals. Sensitivity of the aortic barorec...