Table 1.
Clinical characteristics of the study population
| Clinical characteristics | LQT1 | LQT2 | LQT3 | p‐value |
|---|---|---|---|---|
| # of patients | 879 | 807 | 237 | |
| Male, # (%) | 378 (43) | 362 (45) | 99 (42) | .617 |
| Proband # (%) | 136 (15) | 163 (20) | 33 (14) | .013 |
| Age at 1st ECG, years | 26 ± 21 | 25 ± 21 | 26 ± 20 | .727 |
| Median duration of follow‐up, years | 40.6 ± 15.8 | 39.0 ± 16.1 | 40.1 ± 16.4 | .749 |
| ECG, mean ± SD | ||||
| RR, ms | 831 ± 216 | 820 ± 247 | 840 ± 248 | .625 |
| QRS, ms | 80 ± 15 | 81 ± 16 | 82 ± 14 | .043 |
| QTc, ms | 480 ± 48 | 480 ± 53 | 474 ± 54 | .164 |
| Treatment, # (%) | ||||
| Beta‐blocker use during follow‐up | 478 (54) | 518 (64) | 124 (52) | <.001 |
| LCSD during follow‐up | 8 (1) | 14 (2) | 1 (0) | .209 |
| Pacemaker during follow‐up | 20 (2) | 64 (8) | 14 (6) | <.001 |
| ICD during follow‐up | 95 (11) | 171 (21) | 67 (28) | <.001 |
| Syncope: pts. with 1 or more episodes, # (%) | 318 (36) | 299 (37) | 54 (23) | <.001 |
| Cardiac events, # (%) | ||||
| ACA during follow‐up | 26 (3) | 40 (5) | 13 (5) | .062 |
| Sudden cardiac death during follow‐up | 19 (2) | 28 (3) | 15 (6) | .005 |
| Appropriate ICD shock during follow‐up | 13 (1) | 31 (4) | 8 (3) | .009 |
ACA, aborted cardiac arrest; AF, atrial fibrillation; ICD, implantable cardioverter defibrillator; LCSD, left cardiac sympathetic denervation.