Figure 2From: Severe nocturnal cardiac arrhythmias caused by sleep apnea-induced hypoxemia in males Recorded: oxygen saturation (SaO 2 ), HR - heart rate, types of apnea, sleep stages: Wake - wakefulness, REM - rapid eye movement sleep, S1-S4 - stages of non- REM sleep, EMG - limb electromyogram.Back to article page