Table 4.
Differences Between Patients With Spontaneous and Drug‐Induced Type 1 ECG
| Spontaneous Type 1 (n=181) | Drug‐Induced type1 (n=64) | P Valuea | |
|---|---|---|---|
| Clinical parameters | |||
| Male | 179 (99%) | 61 (95%) | 0.1135 |
| Age, y | 46.0±12.9 | 46.8±13.5 | 0.5918 |
| Symptomatic patients | 62 (34%) | 29 (45%) | 0.133 |
| Syncope | 53 (29%) | 26 (41%) | 0.1194 |
| VT/VF | 9 (5%) | 3 (5%) | 1.0000 |
| Family history of SD | 56 (31%) | 16 (25%) | 0.4265 |
| SCN5A mutation | 13/109 (12%) | 3/30 (10%) | 1.0000 |
| VT/VF during follow‐up | 28 (15%) | 3 (5%) | 0.0257 |
| ECG parameters | |||
| Spontaneous type 1 ECG | 181 (100%) | 0 | ··· |
| PQ interval in lead II (ms) | |||
| Pre SCB | 181±27 | 180±25 | 0.9877 |
| Post SCB | 230±38 | 226±35 | 0.4217 |
| QRS width (ms) | |||
| V1 | |||
| Pre SCB | 108±14 | 101±14 | 0.0004 |
| Post SCB | 134±23 | 128±22 | 0.0085 |
| V2 | |||
| Pre SCB | 108±14 | 102±14 | 0.0011 |
| Post SCB | 136±23 | 130±25 | 0.0041 |
| ST level (mV) | |||
| V1 | |||
| Pre SCB | 0.180±0.111 | 0.096±0.059 | <0.0001 |
| Post SCB | 0.303±0.182 | 0.177±0.094 | <0.0001 |
| V2 | |||
| Pre SCB | 0.331±0.163 | 0.190±0.094 | <0.0001 |
| Post SCB | 0.644±0.276 | 0.444±0.226 | <0.0001 |
| QTc interval (ms) | |||
| V5 | |||
| Pre SCB | 387±27 | 392±27 | 0.2183 |
| Post SCB | 427±36 | 425±31 | 0.7757 |
| Drug‐induced VTA (n) | |||
| Overall | 23 (13%) | 1 (2%) | 0.0068 |
| PVCs | 12 (7%) | 1 (2%) | 0.193 |
| VTs | 11 (6%) | 0 (0%) | 0.071 |
PVCs indicates premature ventricular contractions; SCB, sodium channel blocker; SD, sudden death; VTA, ventricular tachyarrhythmia; VT/VF, ventricular tachycardia/ventricular fibrillation.
a
P value: comparison of ECG parameters in patients with and those without spontaneous type 1 ECG.