Sleep apnea syndrome is a prevalent disease, recognized as an independant risk factor for cardiovascular diseases The gold standard for the diagnosis of sleep apnea is the polysomnography. But polysomnography is time-consuming and very expensive. We developed an algorithm for screening sleep apnea from electrocardiographic signal. This would lead to the simplification of screening sleep apnea by using a two-channels recording device and computerizing the scoring of respiratory events. The validation of the algorithm will consist in comparing the number of apnea and hypopnea per hour of sleep (AHI) detected by the algorithm from the electrocardiographic signal recorded during a standard polysomnography in the Center for Sleep Medicine and Research in Nancy, with the AHI resulted from the standard interpretation of the same polysomnography by experts in sleep scoring (gold standard).

Inclusion Criteria:

• all patients with a polysomnography recorded in the Center for Sleep Medecine and Research (CSMR) in Nancy from january 2019 and june 2020
• results of standard interpretation of polysomnography giving a number of hypopnea and apnea per hour of sleep (AHI) superior to 5

Exclusion Criteria:

• refusal to participate

Patient refered to the CSMR, for which sleep apnea are supected