Table 1.
Demographic and clinical parameters.
| Congenital LQTS (n = 19) | Non-congenital LQTS (n = 30) | p | |
|---|---|---|---|
| Demographic data | |||
| Age (years) | 13.5 ± 5.1 | 12.7 ± 3.3 | 0.52 |
| Sex (M:F) | 8:11 | 17:13 | 0.39 |
| Body weight (kg) | 48.8 ± 21.5 | 46.0 ± 15.5 | 0.60 |
| Body height (cm) | 153.8 ± 23.2 | 154.1 ± 16.8 | 0.95 |
| Body mass index (kg/m2) | 19.5 ± 4.8 | 18.8 ± 3.3 | 0.57 |
| Body surface area (m2) | 1.4 ± 0.4 | 1.4 ± 0.3 | 0.78 |
| Type of arrhythmia | |||
| LQTS | 19 | ||
| SVT | 18 | ||
| VT | 2 | ||
| PVC | 2 | ||
| PAC | 1 | ||
| First-degree heart block | 1 | ||
| Second-degree heart block | 3 | ||
| No arrhythmias | 3 | ||
| Genetic variants | |||
| KCNQ1 (LQT1) | 5 | ||
| KCNH2 (LQT2) | 6 | ||
| SCN5A (LQT3) | 2 | ||
| CACNA1C (LQT8) | 1 | ||
| VUS | 3 | ||
| Negative | 2 | ||
| Medical therapy | |||
| Nadolol | 10 | ||
| Atenolol | 5 | 2 | |
| Propranolol | 2 | 1 | |
| Metoprolol | 2 | ||
| Sotalol | 1 | ||
| Mexiletine | 3 | ||
| Amiodarone | 1 | ||
| Flecainide | 2 | ||
| Propafenone | 1 | ||
| None | 23 | ||
| Cardiac implantable device | |||
| ICD | 2 | ||
| Pacemaker | 2 | ||
| None | 15 | 30 |
|
Abbreviations: ICD, implantable cardioverter defibrillator, LQTS, long QT syndrome, PAC, premature atrial contraction, PVC, premature ventricular contraction, SVT, supraventricular tachycardia, VT, ventricular tachycardia, VUS, variant of uncertain significance.