A cross-sectional study on upright heart rate and BP changing characteristics: basic data for establishing diagnosis of postural orthostatic tachycardia syndrome and orthostatic hypertension

Objective: We aimed to determine upright heart rate and blood pressure (BP) changes to suggest diagnostic criteria for postural orthostatic tachycardia syndrome (POTS) and orthostatic hypertension (OHT) in Chinese children. Methods: In this cross-sectional study, 1449 children and adolescents aged 6-18 years were randomly recruited from two cities in China, Kaifeng in Henan province and Anguo in Hebei province. They were divided into two groups: 844 children aged 6-12 years (group I) and 605 adolescents aged 13-18 years (group II). Heart rate and BP were recorded during an active standing test. Results: 95th percentile (P-95) of delta heart rate from supine to upright was 38 bpm, with a maximum upright heart rate of 130 and 124 bpm in group I and group II, respectively. P-95 of delta systolic blood pressure (SBP) increase was 18 mm Hg and P-95 of upright SBP was 132 mm Hg in group I and 138 mm Hg in group II. P-95 of delta diastolic blood pressure (DBP) increase was 24 mm Hg in group I and 21 mm Hg in group II, and P-95 of upright DBP was 89 mm Hg in group I and 91 mm Hg in group II. Conclusions: POTS is suggested when delta heart rate is >= 38 bpm (for easy memory, >= 40 bpm) from supine to upright, or maximum heart rate >= 130 bpm (children aged 6-12 years) and >= 125 bpm (adolescents aged 13-18 years), associated with orthostatic symptoms. OHT is suggested when delta SBP (increase) is >= 20 mm Hg, and/or delta DBP (increase) >= 25 mm Hg (in children aged 6-12 years) or >= 20 mm Hg (in adolescents aged 13-18 years) from supine to upright; or upright BP >= 130/90 mm Hg (in children aged 6-12 years) or >= 140/90 mm Hg (in adolescents aged 13-18 years).