Table 1.
Demographics and Postural Signs and Catecholamines of the POTS and Healthy Control Subjects
| POTS n=14 | Control n=10 | P Value | |
|---|---|---|---|
| Female, n (%) | 10 (71) | 4 (40) | 0.21 |
| Age, y | 39±13 | 27±6 | 0.013 |
| History of infection, n (%) | 5 (36) | 2 (20) | 0.65 |
| Supine | |||
| Heart rate, min−1 | 76±13 | 73±13 | |
| SBP, mm Hg | 117±14 | 119±9 | |
| DBP, mm Hg | 76±13 | 69±10 | |
| Norepinephrine, pg/mL* | 215±66 | 223±159 | |
| Epinephrine, pg/mL* | 19±13 | 18±20 | |
| Standing | |||
| Heart rate, min−1 | 120±22 | 81±15 | |
| SBP, mm Hg | 123±12 | 118±13 | |
| DBP, mm Hg | 83±13 | 75±10 | |
| Norepinephrine, pg/mL | 873±302 | 553±263 | |
| Epinephrine, pg/mL | 58±32 | 35±31 | |
| Change (∆) from supine to standing | |||
| Heart rate, min−1 | 44±16 | 7±5 | <0.001 |
| SBP, mm Hg | 6±7 | 1±7 | 0.10 |
| DBP, mm Hg | 8±12 | 5±9 | 0.51 |
| Norepinephrine, pg/mL | 658±296 | 330±207 | 0.0065 |
| Epinephrine, pg/mL | 40±21 | 17±23 | 0.0185 |
Data are presented as mean±SD. Comparisons between the POTS and control groups were performed using unpaired t test or Fisher's exact test. DBP indicates diastolic blood pressure; POTS, postural tachycardia syndrome; SBP, systolic blood pressure.
*
SI conversion factor: norepinephrine (pg/mL×0.005911=nmol/L).
*
Epinephrine (pg/mL×5.458=pmol/L).