Impact of night-to-night variability of Sleep Apnoea on Atrial Fibrillation

Consecutive patients with paroxysmal atrial fibrillation will be invited to participate in this study after diagnostic sleep study confirming moderate-to-severe Obstructive Sleep Apnoea (OSA) with AHI greater than or equal to 15. Consenting participants will undergo implantable loop recorder (ILR) insertion for evaluation of Atrial Fibrillation (AF) burden. This will be inserted at local hospital or clinic by experienced cardiac electrophysiologist. It will quantify AF burden in percentage and minutes. All participants will be monitored for 6 months with implantable loop recorder of AF burden and night to night sleep apnoea severity which will be measured for 1 month using a wearable device (SleepImage). Both data will be correlated to see if night to night sleep apnoea severity will change the subsequent day's autonomic function and AF burden. After 6 months of monitoring, all participants will undergo personalized sleep apnoea treatment either as Continuous Positive Airway Pressure (CPAP) or Mandibular Advancement Device (MAD). Autonomic function and AF burden will be compared with nightly sleep data while they are on treatment to correlate whether improvement in nightly sleep apneoa severity improves subsequent day's AF burden and autonomic function. All participants on OSA therapy will be followed up 1 month after commencing treatment to assess and optimize adherence. If participant has suboptimal adherence, they can switched to an alternative therapy as CPAP or MAS. Participants can be reviewed ongoingly as needed basis. SleepImage (SaMD) is a software as medical device worn as a ring or on fingertip during sleep. It measures autonomic function which includes: peripheral arterial tone, heart rate, oxygen saturation and respiration. It also contains actigraphy with a photoplethysmography (PPG) sensor which enables respiratory and sleep analysis. The signals (channels) are continuously sampled during sleep and analyzed with a cardiopulmonary coupling (CDC) algorithm. It is FDA-cleared device to aid clinical diagnosis of sleep disordered breathing in children, adolescents and adults. Sleep and autonomic data will be obtained daily by participants which can be viewed on their app on the phone. This will be reviewed by the research team remotely on a secure, password protected online platform. Sleep data including total sleep time, sleep stage, sleep apnoea/hypoapnoea severity (Apnoea-Hypopnea Index, AHI), heart rate variability and hypoxic burden will be recorded on nightly basis. Additionally, participants will undergo pulse oximetry for 14 days during the initial 6-month and latter 6-month of the study period utilising a standard, commonly used pulse oximeter for assessment of hypoxia pre and post treatment of OSA. It is a non-invasive device that is secured to a participants index finger with a clip.