STUDY OBJECTIVES: Obstructive sleep apnea (OSA) is associated with increased 
cardiovascular morbidity and mortality. Cardiac arrhythmias are common in 
patients with OSA. However, the prevalence and significance of cardiac 
arrhythmias in Asian patients with OSA are not well studied. The aim of this 
study is to determine the prevalence of cardiac arrhythmias in patients with OSA 
in Singapore and to evaluate possible factors that may predispose patients with 
OSA to arrhythmias.
METHODS: A retrospective study of 2,019 patients was carried out from January 
2011 to December 2012 at a sleep center in a tertiary medical center. Of the 
population, 1,457 patients were found to have OSA and 144 patients were found to 
have cardiac arrhythmias. Data collected included patient demographics, 
comorbidities, and polysomnogram parameters.
RESULTS: The prevalence of cardiac arrhythmias in our OSA population is 8.0%, 
compared to that of primary snorers at 4.8% (P = .015). The univariate analysis 
revealed that older age, higher body mass index, comorbidities, and severity of 
OSA, including apnea-hypopnea index (AHI), lowest oxygen saturation (LSAT) and 
hypoxic time were correlated with a higher prevalence of cardiac arrhythmias (P 
< .05). However, the multivariate analysis showed that only age and body mass 
index were significantly correlated with arrhythmias. AHI, LSAT, and hypoxic 
time were no longer statistically significant.
CONCLUSIONS: Our study demonstrated that cardiac arrhythmias are common in 
patients with OSA in Singapore. It also suggests that given the different 
demographics of our population, ethnicity may play a significant role in the 
development of cardiovascular disease among patients with OSA.
COMMENTARY: A commentary on this article appears in this issue on page 1229.