*4.3.6 Sleep*

Patients with advanced stage heart failure often experience insufficient and poor-quality sleep because of periods of pulmonary fluid overloading, resulting in orthopnoea, paroxysmal nocturnal dyspnoea, and nocturia [36].

Respiratory disorders during sleep affect >50% of patients with low ejection fraction. When heart failure becomes more severe, there is an evident increase in the prevalence of Cheyne-Stokes respiration with central sleep apnoea [characterised by a ventilation pattern expressed with hypocapnia associated with hyperventilation]. Another main type of sleep disorder often seen in heart failure patients is obstructive sleep apnoea [OSA]. OSA is especially common if the patient is overweight, has diabetes, and has a large neck circumference, or if there is retro or prognathism. In addition, OSA is accepted as one of the comorbidities contributing to low ejection fraction.

The determination and recording of factors affecting sleep, such as changes in sleep and activity, diet, and drugs used, is important for the provision of sleep hygiene**.**
