Cardiovascular responses to nonrespiratory and respiratory arousals in a porcine model

Abstract

Spontaneous and provoked nonrespiratory arousals can be accompanied by a patterned hemodynamic response. To investigate whether a patterned response is also elicited by respiratory arousals, we compared nonrespiratory arousals (NRA) to respiratory arousals (RA) induced by airway occlusion during non-rapid eye movement sleep. We monitored mean arterial blood pressure (MAP), heart rate, iliac and renal blood flow, and sleep stage in 7 pigs during natural sleep. Iliac and renal vascular resistance were calculated. Airway occlusions were obtained by manually inflating a chronically implanted tracheal balloon during sleep. The balloon was quickly deflated as soon as electroencephalogram arousal occurred. As previously reported, NRA generally elicited iliac vasodilation, renal vasoconstriction, little change in MAP, and tachycardia. In contrast, RA generally elicited iliac and renal vasoconstriction, an increase in MAP and tachycardia. The frequent occurrence of iliac vasoconstriction and arterial pressure elevation following RA but not NRA suggests that sleep state change alone does not account for the hemodynamic response to airway occlusion during sleep.

Heterogeneous activity level of jaw-closing and -opening muscles and its association with arousal levels during sleep in the guinea pig

“…Cardiac activation is typical of transient arousals and is correlated with the level of arousal and with a decrease in ␦EEG activity in NREM sleep (3,29,33,48,52,61). In this study, heart rate increase was only observed for the MA muscle.…”

Sleep Apnea Research in Animals. Past, Present, and Future

“…Many experiments involve a tracheotomy with an intermittently occluded endotracheal tube. Thus far, these techniques have been used in dogs (15), lambs (16), baboons (17), piglets (18,19), and rats (20). A dog model of OSA is depicted in Figure 2, in which a computer-controlled valve would close upon detection of a predetermined period of sleep.…”

Potential clinical use of cardiopulmonary exercise testing in obstructive sleep apnea hypopnea syndrome

“…The neural site(s) responsible for this adaptive increase in BP is not known; however, it is reasonable to speculate that the sympathoexcitatory region in the rostral ventrolateral medulla is likely a potential site of adaptation. A porcine model of OSAHS indicates that arousals may increase peripheral vascular constriction, muscle vasodilation, and visceral vasoconstriction [78,79]. In humans, arousals and sleep disruption could be important factors in acute and chronic BP changes with apneas [80].…”