LAUSR

Sleep architectural disruption is associated with atrial fibrillation (AF), however, associated autonomic influences remain unclear and it is unknown if this detriment persists during wakefulness. We hypothesize diurnal-patterned associations of sleep disruption and autonomic dysfunction in patients with paroxysmal AF We analyzed data from the Sleep Apnea and Atrial Fibrillation Biomarkers and Electrophysiologic Atrial Triggers (SAFEBEAT) study designed to examine paroxysmal AF and sleep apnea involving simultaneous collection of continuous electrocardiogram monitoring (Heartrak Telemetry®) and actigraphy (Actiwatch GTX) for 7-21 days. Heart rate variability (HRV) measures in frequency and time domains were used as surrogates of autonomic function and averaged per sleep/wake per day. A linear mixed-effects model assuming compound symmetry correlation structure was used to assess the relationship of HRV with actigraphy-derived sleep data. The analytic sample (age 60.1±12 years, body mass index 32.6±6.7 kg/m², 36% female, 75% White) included 108 participants with paroxysmal AF. Significant associations were observed between sleep indices and HRV measures during wakefulness: a) Sleep latency with high-frequency power (HFP), b) total sleep time, wakefulness after sleep onset (WASO) and number of awakenings with low-frequency power (LFP), and c) Sleep efficiency with standard deviation of normal R-R intervals (SDNN) and coefficient of variation (CV). During sleep, a) total sleep time was associated with LFP/HFP ratio (LHR), and b) number of awakenings with LHR. Significant sleep-wake interactions were observed between a) Sleep latency and HFP, b) Sleep efficiency with SDNN and CV, c) WASO with SDNN, CV, and LFP, and d) number of awakenings with CV and LFP. Our novel findings indicate actigraphy-based measures of sleep disruption were associated with autonomic function alterations and these relationships exhibited diurnal variability in patients with paroxysmal AF. Results provide unique insights into differential relationships of immediate (during sleep) versus sustained (during wakefulness) autonomic dysfunction related to sleep disruption which may contribute to atrial arrhythmogenesis