Table 1.
Baseline characteristics of the subjects.
| Variable | Total | Normal ECG subgroup∗ |
|---|---|---|
| No. of patients, n | 330 | 231 |
| Age (years), mean±SD | 47.6±17.2 | 45.9±15.1 |
| Male sex, n (%) | 140 (42.4) | 89 (38.5) |
| Potassium level (mmol/L), mean±SD | 4.17±0.39 | 4.35±0.59 |
| No. of normal sinus rhythms, n (%) | 254 (77.0) | 191 (82.7) |
| No. of normal ECG, n (%) | 231 (70.0) | 231 (100.0) |
| Amplitude of T-wave (mV), mean±SD | ||
| Lead II | 0.23±0.11 | 0.24±0.10 |
| Lead V3 | 0.43±0.24 | 0.42±0.23 |
| Lead V4 | 0.40±0.22 | 0.39±0.20 |
| Lead V5 | 0.38±0.19 | 0.37±0.17 |
| Lead V6 | 0.32±0.16 | 0.32±0.14 |
| Gradient of T-wave (mV/s), mean±SD | ||
| Lead II | -3.06±1.51 | -3.1±1.39 |
| Lead V3 | -5.13±3.18 | -5.02±3.07 |
| Lead V4 | -5.02±3.13 | -4.93±2.88 |
| Lead V5 | -4.81±2.78 | -4.78±2.49 |
| Lead V6 | -4.21±2.30 | -4.24±2.07 |
SD: standard deviation; no.: number; ECG: electrocardiogram. ∗Normal ECG or otherwise normal ECG.