Poincaré Plot Width, Morning Urine Norepinephrine Levels, and Autonomic Imbalance in Children With Obstructive Sleep Apnea

Subjects with obstructive sleep apnea and moderate-to-severe nocturnal hypoxemia have enhanced sympathetic activity and reduced parasympathetic drive. Poincaré plot width and urine norepinephrine levels are simple measures of autonomic imbalance in pediatric obstructive sleep apnea.