Heart failure and obstructive apnoea.

Obstructive sleep apnoea (OSA) may aggravate heart failure through the mechanisms of sleep related arousals, systemic hypertension (awake and asleep) and negative intrathoracic pressure which increase cardiac afterload at times of asphyxia and hypoxaemia. Reversal of OSA with nasal continuous positive airway pressure (CPAP), in the setting of heart failure, may return cardiac function to near normal values.