Sleep disordered breathing

The association between atrial fibrillation (AF) and sleep disordered breathing is relatively unknown. Sleep disordered breathing includes obstructive sleep apnoea and central sleep apnoea, revealed as isolated and/or sometimes simultaneous disorders. The Apnoea-Hypopnoea Index (AHI) is used to grade sleep disordered breathing into three severity levels; mild (AHI 5–14); moderate (AHI 15–30); severe sleep disordered breathing (AHI >30).1 In the normal population, the occurrence of sleep disordered breathing varies according to severity, gender and age. Central sleep apnoea can in many cases occur as a consequence of cardiovascular disease.2 In other words, the prevalence of sleep disordered breathing in patients with different types of cardiovascular diseases (e.g. hypertension, heart failure, ischaemic heart disease and stroke), is significantly higher compared to patients without cardiovascular disease.