The pathophysiology of sleep apnoea: What we have learned from animal models of chronic intermittent hypoxia

Sleep apnoea is a common condition associated with significant morbidity and mortality. The English bulldog is the only animal known to have sleep apnoea. In recent years, a number of animal models have been developed which have contributed greatly to our knowledge of the condition. These models develop a number of pathophysiological changes similar to human sleep apnoea such as systemic and pulmonary hypertension, increased haematocrit, and effects on blood coaguability, cardiac rhythmogenesis and central nervous system and upper airway muscle function. This review will describe what has been learned from these models concerning the pathophysiology of sleep apnoea with special emphasis on the role played by intermittent hypoxia.