Variation of Electrocardiogram Features Across Sleep Stages in Healthy Controls and in Patients with Sleep Apnea Hypopnea Syndrome

Abstract

Sleep apnea hypopnea syndrome (SAHS) is an independent risk factor for various cardiovascular diseases. Electrocardiogram (ECG) features such as the RR, PR, QT, QTc, Tpe intervals and the Tpe/QT, Tpe/QTc ratios are used to predict and study cardiovascular diseases. It is not clear whether regular patterns of PR and Tperelated features across sleep stages exist in SAHSs or healthy controls nor whether sleep stages affect the shortand long-range influences of respiratory events on ECG indices. We enrolled 36 healthy controls and 35 patients with SAHS in our study and analyzed the abovementioned ECG features. In the healthy controls, a significant regularity existed in these indices across sleep stages, which were weakened or disturbed in the patient group, especially the Tpe-related features. The differences between the patients and healthy controls were generally consistent across all sleep stages: patients had smaller RR, PR, QT and Tpe/QTc values, but larger QTc, Tpe and Tpe/QT values. After filtering the short-range influence of respiratory events, the differences in most features remained highly significant, except the QT interval. In the patient group, respiratory events decreased RR and PR intervals in most sleep stages and increased the Tpe-related features' values in deep sleep stages. These results may aid in the study of the relationships among SAHS, sleep disorders and cardiovascular diseases.

Heart Rate Correction of the J-to-Tpeak Interval

“…Both original studies were approved by the relevant ethics boards (California Clinical Trials, Glendale; Spaulding Clinical Services, Milwaukee; Parexel International, Baltimore) and all participants gave written informed consent according to the Helsinki declaration. Because of the known effect of sleep on the QT interval duration 14 which might be expected also for the JTp and JT50 intervals 15 , the present study used only day-time portions of the recordings.…”

Inter-sleep stage variations in corrected QT interval differ between obstructive sleep apnea patients with and without stroke history

“…Despite the evidence regarding altered autonomic system activity in OSA patients, previous results regarding QTc interval variations in OSA patients are conflicting. Zeng et al reported a decrease in QTc as sleep gets deeper and an increase in QTc during REM sleep—the highest QTc intervals in REM sleep [ 9 ]. Lanfranchi et al showed insignificant changes in QTc intervals during wake, N2, and N3 sleep and a significant increase in REM sleep [ 15 ].…”

“…The results regarding the variations of QTc intervals in different sleep stages are also conflicting. While studies show different trends or insignificant changes in QTc interval toward deeper sleep stages in non-rapid eye movement (non-REM) stages, the longest QTc intervals are reported to occur in REM sleep [ 9 , 15 , 16 ]. However, in these studies, variations of QTc intervals were not investigated separately in different sleep stages and during wake [ 9 , 14 – 16 ].…”

“…Several studies have demonstrated the association between OSA and QTc prolongation [9][10][11][12] albeit conflicting results exist [13,14]. The results regarding the variations of QTc intervals in different sleep stages are also conflicting.…”

Applicability of a Textile ECG-Belt for Unattended Sleep Apnoea Monitoring in a Home Setting

“…Therefore, ECG is a widely used method for monitoring and assessing a patient’s physical and mental health condition. This is particularly relevant for sleep apnoea syndrome (SAS), where respiratory events are known to affect ECG features [1]. SAS is a prevalent disorder characterized by pauses in breathing or periods of shallow breathing during sleep, potentially resulting in cardiovascular morbidity and increased daytime sleepiness, with associated risk for car accidents [2,3].…”