Table 1.
Baseline characteristics of the study population included in the current study.
| Variable | Healthy controls, n = 21 | PACS, n = 42 | PACS + POTS, n = 20 | PACS–POTS, n = 22 | p-value, PACS vs healthy controls | p-value, POTS + vs POTS – |
|---|---|---|---|---|---|---|
| Demographics | ||||||
| Female sex, n (%) | 20 (95) | 41 (98) | 19 (95) | 22 (100) | > 0.99 | > 0.99 |
| Age, years | 43 ± 6 | 42 ± 10 | 39 ± 11 | 44 ± 11 | 0.52 | 0.09 |
| PACS-duration (months) | N/A | 18 ± 3 | 18 ± 3 | 19 ± 3 | N/A | 0.36 |
| Preexisting comorbidities before PACS diagnosis, n (%) | ||||||
| Hypertension | 0 (0) | 2 (5) | 1 (5) | 1 (5) | > 0.99 | > 0.99 |
| Diabetes mellitus | 0 (0) | 0 (0) | 0 (0) | 0 (0) | > 0.99 | > 0.99 |
| Asthma | 0(0) | 7 (17) | 4 (20) | 3 (14) | 0.08 | 0.69 |
| Depression/anxiety/clinical burnout | 0 (0) | 11 (26) | 2 (10) | 9 (40) | 0.01 | 0.04 |
| ME/CFS | 0 (0) | 1 (2) | 0(0) | 1 (5) | > 0.99 | > 0.99 |
| EDS | 0 (0) | 3 (7) | 2 (10) | 1 (5) | 0.54 | 0.60 |
| Hypothyroidism | 0 (0) | 3 (7) | 2 (10) | 1 (5) | 0.54 | 0.60 |
| Pharmacological treatment at inclusion, n (%) | ||||||
| Ivabradine | 0 (0) | 16 (38) | 12 (60) | 4 (18) | 0.001 | 0.01 |
| β-blockers | 0 (0) | 13 (31) | 6 (30) | 7 (32) | 0.002 | > 0.99 |
| Ca2+ channel blockers | 0 (0) | 3 (7) | 2 (10) | 1 (5) | 0.003 | 0.61 |
| SSRI | 0 (0) | 10 (24) | 5 (25) | 5 (23) | 0.02 | > 0.99 |
| Inhalation steroids | 0 (0) | 10 (24) | 4 (20) | 6 (27) | 0.02 | 0.72 |
| Sedative and hypnotics | 0 (0) | 16 (38) | 5 (25) | 11 (50) | 0.01 | 0.12 |
| POTS-associated | ||||||
| Delta HR on HUT (bpm) | N/A | N/A | 40 ± 15 | 19 ± 8 | N/A | < 0.001 |
| Average HR on 24 h Holter ECG | N/A | N/A | 77 ± 7 | 75 ± 9 | N/A | 0.27 |
Data are presented as mean and standard deviation or numbers (n) and %. Significant differences were calculated with student’s t-test or chi-square test and p-values are shown.
b-blocker beta receptor blockers, bpm beats per minute, ECG electrocardiogram, EDS Ehler-Danlos syndrome, HR heart rate, HUT head-up TILT test, ME/CFS Myalgic encephalomyelitis/chronic fatigue syndrome, N/A not applicable, PACS post-acute COVID-19 syndrome, POTS postural orthostatic tachycardia syndrome, SSRI selective serotonin reuptake inhibitor.