Bradyarrhythmias Associated with the Obstructive Sleep Apnoea Syndrome: A Precursor to Life-threatening Arrhythmias?

摘要

Chronic Obstructive Pulmonary Disease (COPD) is a leading cause of global morbidity that is predicted to become the third most common cause of death worldwide by the year 20201. Obstructive sleep apnoea syndrome (OSAS) is also highly prevalent and is estimated to affect 5% of adults in western countries2. The co-existence of both COPD and OSAS in the same patient is termed the Overlap syndrome3,4. Overlap patients have more pronounced nocturnal hypoxemia and appear to be at increased risk of death compared with COPD patients matched for Global Initiative for COPD stage without OSA. We present a case of a patient with mild OSA and moderate COPD who was observed on CPAP titration polysomnography to have moderate obstructive sleep apnoea during rapid eye movement (REM) sleep (REM apnoea-hypopnea index (AHI) 28/hr.), with associated Wenckebach second-degree atrioventricular (AV) heart block observed during the nadir of oxygen desaturation associated with obstructive apnoeas. This led to further investigation with a one month event recording which showed progression of a benign Type I Wenckebach second-degree AV heart block to life-threatening Type II AV second-degree heart block and complete AV block with 3.9 seconds of ventricular asystole. Bradyarrhythmias during sleep observed in patients with COPD and OSAS may be a precursor to more life-threatening arrhythmias.