Baseline clinical characteristics
| n (%) | |
| Male gender | 50 (58) |
| Age, years (median (range)) | 12.4 (0–18.4) |
| Weight, kg (median (range)) | 38.6 (2–101) |
| Cardiac medications | |
| Beta-blockers | 91 (55) |
| Disopyramide | 38 (23) |
| Calcium channel blockers | 16 (10) |
| Amiodarone | 10 (6) |
| Comorbidities (n) | |
| ENT | |
| OSA | 3 |
| Orthopaedic | |
| Scoliosis | 4 |
| Polyarthralgia | 1 |
| Respiratory | |
| Asthma | 4 |
| Congenital cardiac disease | |
| VSD | 1 |
| Aortic stenosis | 1 |
| Neurology | |
| Epilepsy | 1 |
| Autistic spectrum disorder | 3 |
| Developmental delay (acquired/congenital) | 3 |
| Hydrocephalus | 1 |
| Metabolic | |
| Diabetes mellitus | 2 |
| Renal | |
| Polycystic kidney | 1 |
Data expressed as number (%). Total number of patients is 86 unless otherwise stated.
ENT, ears, nose and throat; OSA, obstructive sleep apnoea; VSD, ventricular septal defect.