Table 2.
Comparison of baseline ECG parameters between responders and non-responders to metoprolol in children with POTS in the training set
| Items | Responders | Non-responders | t/Z value | P value |
|---|---|---|---|---|
| P wave amplitude (mV) | 0.119 (0.100, 0.132) | 0.109 (0.081, 0.133) | −1.974 | 0.048 |
| Pcmax (ms) | 117.2 ± 13.5 | 104.5 ± 13.1 | 4.292 | < 0.01 |
| Pcmin (ms) | 61.6 ± 10.8 | 70.9 ± 8.7 | −4.133 | < 0.01 |
| Pd (ms) | 48.9 ± 10.6 | 29.5 ± 7.9 | 8.965 | < 0.01 |
| Pcd (ms) | 55.6 ± 11.6 | 33.6 ± 8.9 | 9.157 | < 0.01 |
| QTcmax (ms) | 452.1 ± 28.9 | 441.5 ± 23.4 | 1.768 | 0.080 |
| QTcmin (ms) | 369.7 ± 30.3 | 393.0 ± 23.2 | −3.736 | < 0.01 |
| QTd (ms) | 70.8 (52.2, 89.1) | 38.6 (32.2, 46.1) | −5.501 | < 0.01 |
| QTcd (ms) | 78.1 (62.5, 102.3) | 43.3 (37.6, 57.3) | −5.476 | < 0.01 |
| Tpemax (ms) | 109.7 (100.0, 119.3) | 96.7 (88.4, 104.2) | −4.328 | < 0.01 |
| Tpemin (ms) | 50.5 ± 10.0 | 59.9 ± 9.3 | −4.385 | < 0.01 |
| Tped (ms) | 56.7 (51.2, 70.1) | 36.8 (31.4, 41.3) | −6.870 | < 0.01 |
ECG electrocardiogram, POTS postural tachycardia syndrome, Pcmax the maximum value of P wave duration in 12 leads of ECG after correction, Pcmin the minimum value of P wave duration in 12 leads of ECG after correction, Pd P wave duration dispersion, Pcd Pd after correction, QTcmax the maximum value of QT interval in 12 leads of ECG after correction, QTcmin the minimum value of QT interval in 12 leads of ECG after correction, QTd QT interval dispersion QTcd QTd after correction, Tpemax the maximum value of T-peak-to-T-end interval in 12 leads of ECG, Tpemin the minimum value of T-peak-to-T-end interval in 12 leads of ECG, Tped T-peak-to-T-end dispersion