Prevalence of cardiac arrhythmias in patients of obstructive sleep apnea syndrome and changes after 6 months of continuous positive airway pressure therapy

Obstructive sleep Apnoea (OSA) has generated lot of attention recently. The prevalence of OSA in adult Indian population is approximately 3.5% and the majority of these patients remain undiagnosed. OSA is associated with repeated episodes of hemoglobin desaturation and higher inspiratory effort, combined with repeated arousals during sleep. This causes repeated sympathetic and parasympathetic stimulation. This has been postulated to be associated with both electric and mechanical remodeling of the heart leading to cardiac arrhythmias. In this study, we try to find a correlation between OSA and cardiac arrhythmias and to find the type of arrhythmia as the secondary aim.This study was conducted over three year period at a tertiary care hospital in Mumbai. We screened 186 patients with proven OSA (Apnoea Hypopnea Index> 5). Among these, those with pre-existing structural heart disease or arrhythmia or those not consenting for the study were excluded. 121 subjects were taken up for the study. 01 was lost to follow up, leading to a final sample size of 120. These 120 patients with proven OSAand no pre- existing cardiac pathology were subjected to 24 hour ambulatory Holter monitoring to determine the prevalence of cardiac arrhythmias among this cohort. It was found that 30% of this population had some or the other arrhythmia. (n = 36). Various factors such as age, metabolic and endocrine ailments and others were also accounted for.In the follow up to this study, these 36 patients were advised to use CPAP. Following 06 months of effective CPAP use, these subjects underwent repeat 24 hour Holter examination. Unsurprisingly, significant reduction in prevalence of cardiac arrhythmia was noticed. Now, out of this cohort of 36 subjects, only 02 were found to have cardiac arrhythmia