Predictors of impending cardiac arrhythmias by electrocardiographic markers in proven obstructive sleep apnea patients

Abstract

Background: Obstructive sleep apnoea is proved to be one of the causes of sudden cardiac death due to undocumented transient cardiac arrhythmias.So we studied the changes in various electrocardiographic parameters (P wave duration, QRS duration and Tpeak to Tend interval) and its association with increasing severity of OSA by AHI to predict the risk of impending cardiac atrial and ventricular arrhythmias in these patients. Objective: This study compares the risk of impending cardiac arrhythmias by electrocardiographic parameters with the increasing severity of obstructive sleep apnoea by AHI (apnoea-hypopnea index) in polysomnnography. Methodology: The study was conducted in a rural based teaching tertiary care hospital in Puducherry,India. The electrocardiogram(ECG) of the 30 proven OSA patients were analysed for parameters like P wave duration, QRS duration and peak of T wave to end of T wave interval. Any deviation from the normal duration is recorded and compared with the severity of OSA by AHI to estimate the risk of arrhythmogenicity Results: Out of 30 OSA patients in the study group 7 (23.3%) were found to have mild OSA [i.e AHI= 5 TO 14 events/hr] , 6 (20%) were found to have moderate OSA [i.e AHI=15 to 29 events/hr] and 17(56.7%) were found to have severe OSA[i.e AHI=30 and above]. The p value is significant [ Conclusion: We concluded that the increase in duration of P wave, QRS duration and prolongation of Tp-Te interval in electrocardiogram is associated with increasing severity of obstructive sleep apnoea tends to possess significant risk of developing impending cardiac atrial and ventricular arrhythmias respectively which can be attributed to one of the causes of sudden cardiac death in OSA patients.