Acute and chronic effects of airway obstruction on canine left ventricular performance.

We used a canine model of chronic obstructive sleep apnea (OSA) to examine the effects of intermittent airway occlusion during sleep on left ventricular (LV) performance. Studies were performed in four dogs. The effects of acute airway occlusion on LV pressure and volume (on a background of chronic OSA) were determined with an impedance catheter and a high fidelity manometer.

Baroreflex control of heart rate in a canine model of obstructive sleep apnea.

We have recently demonstrated the development of systemic hypertension in a canine model of obstructive sleep apnea (OSA), but the underlying physiological mechanisms were not identified. Therefore, the purpose of this study was to examine the effect of OSA on arterial baroreceptor control of heart rate (HR) in this canine model. OSA was produced in three dogs for 1 to 3 mo.

Sleep architecture in a canine model of obstructive sleep apnea.

Obstructive sleep apnea (OSA) causes recurrent sleep disruption that is thought to contribute to excessive daytime sleepiness in patients with this disorder. The purpose of this study was to determine the specific effects of OSA on overall sleep architecture in a canine model of OSA. The advantage of this model is that sleep during long-term OSA can be compared to both normal sleep before OSA and recovery sleep after OSA.

Ventilatory and arousal responses to hypoxia and hypercapnia in a canine model of obstructive sleep apnea.

We have previously described a canine model of obstructive sleep apnea (OSA) in which sleep-wake state is monitored continuously by a computer that produces tracheal occlusion when sleep occurs. Our aim was to assess the effects of long-term application of this model on resting ventilation and on the ventilatory and arousal responses to hypercapnia and hypoxia. Five dogs were maintained on the model for 15.

Effect of obstructive sleep apnea versus sleep fragmentation on responses to airway occlusion.

Although the acute physiologic responses to apnea in patients with obstructive sleep apnea (OSA) have been well documented, the changes in these responses over the course of the disease have not been investigated. The purpose of this study was to use a canine model of OSA to examine the long-term effects of sleep apnea on the acute responses to airway occlusion during sleep. Four dogs were studied during a control period before induction of OSA, during a period of OSA (83-133 d), and following cessation of OSA.

Obstructive sleep apnea as a cause of systemic hypertension. Evidence from a canine model.

Several epidemiological studies have identified obstructive sleep apnea (OSA) as a risk factor for systemic hypertension, but a direct etiologic link between the two disorders has not been established definitively. Furthermore, the specific physiological mechanisms underlying the association between OSA and systemic hypertension have not been identified. The purpose of this study was to systematically examine the effects of OSA on daytime and nighttime blood pressure (BP).