Sleep-dependent changes in the coupling between heart period and blood pressure in human subjects

2008 ◽  
Vol 294 (5) ◽  
pp. R1686-R1692 ◽  
Author(s):  
Alessandro Silvani ◽  
Daniela Grimaldi ◽  
Stefano Vandi ◽  
Giorgio Barletta ◽  
Roberto Vetrugno ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Eye Movement ◽  
Sleep Disordered Breathing ◽  
Human Subjects ◽  
Rapid Eye Movement Sleep ◽  
Heart Period ◽  
Low Frequencies ◽  
Feed Forward ◽  
Finger Blood Pressure ◽  
Spontaneous Fluctuations

We investigated whether in human subjects, the pattern of coupling between the spontaneous fluctuations of heart period (HP) and those of systolic blood pressure (SBP) differs among wake-sleep states. Polysomnographic recordings and finger blood pressure measurements were performed for 48 h in 15 nonobese adults without sleep-disordered breathing. The cross-correlation function (CCF) between the fluctuations of HP and SBP at frequencies <0.15 Hz was computed during quiet wakefulness (QW), light (stages 1 and 2) and deep (stages 3 and 4) nonrapid-eye-movement sleep (NREMS), and rapid-eye-movement sleep (REMS). A positive correlation between HP and the previous SBP values, which is the expected result of baroreflex feedback control, was observed in the sleep states but not in QW. In deep NREMS, the maximum CCF value was significantly higher than in any other state, suggesting the greatest baroreflex contribution to the coupling between HP and SBP. A negative correlation between HP and the subsequent SBP values was also observed in each state, consistent with the mechanical feed-forward action of HP on SBP and with central autonomic commands. The contribution of these mechanisms to the coupling between HP and SBP, estimated from the minimum CCF value, was significantly lower in deep NREMS than either in light NREMS or QW. These results indicate that the pattern of coupling between HP and SBP at low frequencies differs among wake-sleep states in human subjects, with deep NREMS entailing the highest feedback contribution of the baroreflex and a low effectiveness of feed-forward mechanisms.

scholarly journals Control of cardiovascular variability during undisturbed wake-sleep behavior in hypocretin-deficient mice

2012 ◽  
Vol 302 (8) ◽  
pp. R958-R964 ◽  
Author(s):  
Alessandro Silvani ◽  
Stefano Bastianini ◽  
Chiara Berteotti ◽  
Viviana Lo Martire ◽  
Giovanna Zoccoli
Keyword(s):  
Blood Pressure ◽  
Eye Movement ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Low Frequencies ◽  
Sleep Behavior ◽  
Cardiovascular Variability ◽  
Lower Amplitude ◽  
Spontaneous Behavior ◽  
Deficient Mice

The central neural mechanisms underlying differences in cardiovascular variability between wakefulness, non-rapid-eye-movement sleep (NREMS), and rapid-eye-movement sleep (REMS) remain poorly understood. These mechanisms may involve hypocretin (HCRT)/orexin signaling. HCRT signaling is linked to wake-sleep states, involved in central autonomic control, and impaired in narcoleptic patients. Thus, we investigated whether HCRT signaling plays a role in controlling cardiovascular variability during spontaneous behavior in HCRT-deficient mice. HCRT-ataxin3 transgenic mice lacking HCRT neurons (TG), knockout mice lacking HCRT peptides (KO), and wild-type controls (WT) were instrumented with electrodes for sleep recordings and a telemetric blood pressure transducer. Fluctuations of systolic blood pressure (SBP) and heart period (HP) during undisturbed wake-sleep behavior were analyzed with the sequence technique, cross-correlation functions, and coherent averaging of SBP surges. During NREMS, all mice had lower SBP variability, greater baroreflex contribution to HP control at low frequencies, and greater amplitude of the central autonomic and baroreflex changes in HP associated with SBP surges than during wakefulness. During REMS, all mice had higher SBP variability and depressed central autonomic and baroreflex HP controls relative to NREMS. HP variability during REMS was higher than during NREMS in WT only. TG and KO also had lower amplitude of the cardiac baroreflex response to SBP surges during REMS than WT. These results indicate that chronic lack of HCRT signaling may cause subtle alterations in the control of HP during spontaneous behavior. Conversely, the integrity of HCRT signaling is not necessary for the occurrence of physiological sleep-dependent changes in SBP variability.

An induced blood pressure rise does not alter upper airway resistance in sleeping humans

1998 ◽  
Vol 84 (1) ◽  
pp. 269-276 ◽  
Author(s):  
Christine R. Wilson ◽  
Shalini Manchanda ◽  
David Crabtree ◽  
James B. Skatrud ◽  
Jerome A. Dempsey
Keyword(s):  
Blood Pressure ◽  
Arterial Pressure ◽  
Eye Movement ◽  
Airway Resistance ◽  
Pressure Rise ◽  
Upper Airway ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Upper Airway Resistance ◽  
Blood Pressure Rise

Wilson, Christine R., Shalini Manchanda, David Crabtree, James B. Skatrud, and Jerome A. Dempsey. An induced blood pressure rise does not alter upper airway resistance in sleeping humans. J. Appl. Physiol. 84(1): 269–276, 1998.—Sleep apnea is associated with episodic increases in systemic blood pressure. We investigated whether transient increases in arterial pressure altered upper airway resistance and/or breathing pattern in nine sleeping humans (snorers and nonsnorers). A pressure-tipped catheter was placed below the base of the tongue, and flow was measured from a nose or face mask. During non-rapid-eye-movement sleep, we injected 40- to 200-μg iv boluses of phenylephrine. Parasympathetic blockade was used if bradycardia was excessive. Mean arterial pressure (MAP) rose by 20 ± 5 (mean ± SD) mmHg (range 12–37 mmHg) within 12 s and remained elevated for 105 s. There were no significant changes in inspiratory or expiratory pharyngeal resistance (measured at peak flow, peak pressure, 0.2 l/s or by evaluating the dynamic pressure-flow relationship). At peak MAP, end-tidal CO2 pressure fell by 1.5 Torr and remained low for 20–25 s. At 26 s after peak MAP, tidal volume fell by 19%, consistent with hypocapnic ventilatory inhibition. We conclude that transient increases in MAP of a magnitude commonly observed during non-rapid-eye-movement sleep-disordered breathing do not increase upper airway resistance and, therefore, will not perpetuate subsequent obstructive events.

Patterned cardiovascular responses to sleep and nonrespiratory arousals in a porcine model

1998 ◽  
Vol 85 (4) ◽  
pp. 1285-1291 ◽  
Author(s):  
Sandrine H. Launois ◽  
Joseph H. Abraham ◽  
J. Woodrow Weiss ◽  
Debra A. Kirby
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Eye Movement ◽  
Arterial Blood Pressure ◽  
Vascular Resistance ◽  
Mean Arterial Blood Pressure ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Arterial Blood

Patients with obstructive sleep apnea experience marked cardiovascular changes with apnea termination. Based on this observation, we hypothesized that sudden sleep disruption is accompanied by a specific, patterned hemodynamic response, similar to the cardiovascular defense reaction. To test this hypothesis, we recorded mean arterial blood pressure, heart rate, iliac blood flow and vascular resistance, and renal blood flow and vascular resistance in five pigs instrumented with chronic sleep electrodes. Cardiovascular parameters were recorded during quiet wakefulness, during non-rapid-eye-movement and rapid-eye-movement sleep, and during spontaneous and induced arousals. Iliac vasodilation (iliac vascular resistance decreased by −29.6 ± 4.1% of baseline) associated with renal vasoconstriction (renal vascular resistance increased by 10.3 ± 4.0%), tachycardia (heart rate increase: +23.8 ± 3.1%), and minimal changes in mean arterial blood pressure were the most common pattern of arousal response, but other hemodynamic patterns were observed. Similar findings were obtained in rapid-eye-movement sleep and for acoustic and tactile arousals. In conclusion, spontaneous and induced arousals from sleep may be associated with simultaneous visceral vasoconstriction and hindlimb vasodilation, but the response is variable.

Respiratory and cardiovascular responses to increased and decreased carotid sinus pressure in sleeping dogs

1995 ◽  
Vol 78 (5) ◽  
pp. 1688-1698 ◽  
Author(s):  
K. W. Saupe ◽  
C. A. Smith ◽  
K. S. Henderson ◽  
J. A. Dempsey
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Eye Movement ◽  
Carotid Sinus ◽  
Minute Ventilation ◽  
Control Level ◽  
Cardiovascular Responses ◽  
Systemic Blood Pressure ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep

The purpose of this study was to determine the effects of changing blood pressure in the carotid sinus (Pcs) on ventilatory output during wakefulness and non-rapid-eye-movement sleep in unanesthetized dogs. Eight dogs were chronically instrumented so that ventilation, heart rate, and blood pressure could be measured while pressure in the isolated carotid sinus was rapidly changed by means of an extracorporeal perfusion circuit. Raising Pcs 35–75 mmHg consistently reduced ventilation 15–40% in a dose-response fashion, with little or no further diminution in minute ventilation as Pcs was further increased > 75 mmHg above control level. This decrease in minute ventilation was immediate, due primarily to a decrease in tidal volume, and was sustained over the 20-s period of elevated Pcs. Increases in Pcs also caused immediate sustained reductions in systemic blood pressure and heart rate, both of which also fell in a dose-dependent fashion. The ventilatory and systemic cardiovascular responses to increased Pcs were the same during wakefulness and non-rapid-eye-movement sleep. Decreasing Pcs 40–80 mmHg caused a sudden carotid chemoreceptor-mediated hyperpnea that was eliminated by hyperoxia. We conclude that increasing Pcs causes a reflex inhibition of ventilation and that this reflex may play a role in sleep-disordered breathing.

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