Screening of obstructive sleep apnea syndrome by the deep breathing technique

Obstructive sleep apnea syndrome (OSAS) is associated with alterations in heart rate variability (HRV) in relation to chronic autonomic dysfunction. We tested the ability of the deep breathing technique -a simple way to evaluate HRV- to identify OSAS patients.Consecutive patients referred for suspected OSAS (without obesity, diabetes and heart diseases) were included. They underwent a measure of HRV at rest, and of heart rate (HR) oscillations during expiration vs. inspiration (DeltaHROf 31 included subjects (77% male), 14 had mild to moderate OSAS (apnea/hypopnea index, AHI median [IQR]: 18 [12]), and 17 had no OSAS. The conventional HRV analysis did not reveal any difference between the groups with vs. without OSAS. However, the DeltaHRThe deep breathing technique accurately identifies a reduction in cardiac changes in patients with mild to moderate OSAS. It could be used as a simple screening tool to select patients for polysomnography.