Effect of continuous positive airway pressure therapy on circadian patterns of cardiac repolarization in patients with obstructive sleep apnoea: data from a randomized trial

Obstructive sleep apnoea (OSA) has been proposed as an independent risk factor for sudden cardiac death (SCD). This study takes advantage of a previous randomized trial and seeks to evaluate circadian patterns of the QTc-interval, a marker of cardiac repolarization and biomarker for SCD, in patients with OSA. We hypothesized that patients with OSA would exhibit longest QTc during the night-time and that continuous positive airway pressure (CPAP) therapy would reverse this.