Comparative analysis of autonomic nervous system function in patients with postural orthostatic tachycardia syndrome versus a head-up tilt testing-negative cohort

The findings suggest that pre-HUTT HRV, as assessed by 24-hour Holter monitoring, may provide greater clinical relevance in distinguishing between these groups. The study reveals that patients with POTS demonstrate abnormalities in autonomic regulation, characterized by a decrease in sympathetic activity alongside an increase in parasympathetic activity. The dysregulation of autonomic balance likely contributes to the elevated incidence of syncope and presyncope events observed in patients with POTS.