Enhancing the Diagnosis and Management of Obstructive Sleep Apnoea in Atrial Fibrillation Patients

Background: Atrial fibrillation (AF), is the most common sustained cardiac arrhythmia, and significantly increases the risk of stroke and cardiovascular mortality. It is strongly associated with obstructive sleep apnoea (OSA). Aims: 1. Examine the epidemiology of OSA in a hospital cohort with AF. 2. Compare the diagnostic accuracy of clinical screening tools for OSA in patients with AF. 3. Compare cardiac autonomic function in AF patients with and without OSA. 4. Conduct a pilot study of mandibular advancement splint (MAS) therapy for OSA in AF patients. Methods: 107 AF patients were recruited. The diagnostic accuracy of screening tools including a level 3 (portable) sleep study device as compared to polysomnography in AF patients was assessed. Cardiac autonomic function as a potential mechanistic link between OSA and AF was assessed using Heart Rate Variability (HRV). A pilot study of OSA treatment in AF patients using MAS therapy was conducted. Results: 62.6% of patients were newly diagnosed with OSA. Patients with moderate to severe OSA showed an increased BMI, neck circumference and Mallampati score, but were not significantly different in terms of daytime somnolence. Oxygen desaturation index (ODI) derived from a Level 3 portable sleep study device performed best for the diagnosis of moderate to severe and severe OSA, with excellent diagnostic accuracy (AUC 0.899, 95% CI 0.838 – 0.960 and AUC 0.925, 95% CI 0.859 – 0.991 respectively). We found a chronic increase in parasympathetic nervous activity in paroxysmal AF patients with OSA. MAS therapy showed high rates of acceptance, compliance and efficacy in AF patients. Conclusions: This thesis contributes to our understanding of the association between AF and OSA across a spectrum o