Obstructive sleep apnea (polysomnogram) (1)

Obstructive sleep apnea superimposed on a pattern of Cheyne-Stokes breathing in a 77-year-old man with snoring and apneas witnessed by wife. During the first 12 seconds of the tracing, partial airway closure will occur as the patient becomes drowsy. During the next 12 seconds, as he enters stage 1 sleep, the upper airway closes completely resulting in gradual diminution of respiratory effort. During the second half of the tracing, respiratory effort increases but the airway remains closed until an arousal occurs. (Contributed by Dr. Michael Aldrich.)