Table 2.
Baseline and ambulatory Holter electrocardiography parameters of the study population
| Variables | Group 1 (n = 32) | Group 2 (n = 36) | Group 3 (n = 32) | p values (groups)* | ||
|---|---|---|---|---|---|---|
| 1 vs 2 | 1 vs 3 | 2 vs 3 | ||||
| Maximum Heart Rate (beats/min) | 123.60 ± 17.10 | 120.40 ± 20.10 | 116.80 ± 13.20 | 0.720 | 0.259 | 0.671 |
| Minimum Heart Rate (beats/min) | 58.90 ± 7.40 | 54.90 ± 8.60 | 57.10 ± 7.30 | 0.097 | 0.638 | 0.481 |
| Average Heart Rate (beats/min) | 73.40 ± 13.40 | 72.40 ± 14.60 | 73.90 ± 12.00 | 0.940 | 0.980 | 0.855 |
| Number of VPCs (median/24 h) | 543.00 ± 288.00 | 2779 ± 1041 | 8358 ± 2911 | < 0.001 | < 0.001 | < 0.001 |
| Number of VPCs (median/h) | 22.80 ± 12.40 | 117.50 ± 46.30 | 358.00 ± 125.20 | < 0.001 | < 0.001 | < 0.001 |
| Percent of VPC number (24 h) | 0.50 ± 0.23 | 2.76 ± 1.03 | 7.90 ± 2.72 | < 0.001 | < 0.001 | < 0.001 |
| Lead V2 | ||||||
| QT (ms) | 358.00 ± 22.80 | 378.10 ± 35.50 | 387.00 ± 25.30 | 0.013 | < 0.001 | 0.419 |
| QTc (ms) | 414.30 ± 32.20 | 410.50 ± 27.00 | 427.30 ± 33.80 | 0.867 | 0.222 | 0.071 |
| Tp-e (ms) | 94.30 ± 9.40 | 100.50 ± 9.70 | 106.50 ± 7.90 | 0.016 | < 0.001 | 0.023 |
| cTp-e (ms) | 108.60 ± 14.80 | 110.00 ± 16.30 | 117.70 ± 11.50 | 0.923 | 0.038 | 0.079 |
| Tp-e/QT | 0.26 ± 0.02 | 0.27 ± 0.03 | 0.28 ± 0.02 | 0.854 | 0.239 | 0.493 |
| Tp-e/QTc | 0.23 ± 0.02 | 0.24 ± 0.03 | 0.25 ± 0.03 | 0.007 | 0.001 | 0.689 |
| Lead V5 | ||||||
| QT (ms) | 363.70 ± 26.20 | 380.50 ± 41.50 | 389.30 ± 20.50 | 0.075 | 0.004 | 0.485 |
| QTc (ms) | 421.00 ± 37.00 | 413.00 ± 29.30 | 429.70 ± 29.10 | 0.554 | 0.524 | 0.084 |
| Tp-e (ms) | 91.30 ± 9.20 | 94.00 ± 12.20 | 101.10 ± 8.80 | 0.519 | 0.001 | 0.015 |
| cTp-e (ms) | 106.50 ± 15.10 | 102.3 ± 13.9 | 112.0 ± 14.0 | 0.453 | 0.280 | 0.018 |
| Tp-e/QT | 0.25 ± 0.02 | 0.25 ± 0.03 | 0.26 ± 0.03 | 0.895 | 0.372 | 0.163 |
| Tp-e/QTc | 0.22 ± 0.02 | 0.23 ± 0.03 | 0.24 ± 0.03 | 0.244 | 0.021 | 0.465 |
| QTd (ms) | 23.30 ± 6.40 | 26.3 ± 13.1 | 34.3 ± 13.4 | 0.537 | 0.001 | 0.015 |
QTc: corrected QT; QTd: QT dispersion; Tp-e: T wave peak-to-end interval; cTp-e: corrected Tp-e; ms: millisecond; VPC: ventricular premature contraction; Data are presented as mean ± SD. Statistically significant p values shown in bold;
*
ANOVA test was performed to study differences among the three groups. The post hoc Tukey’s test was performed after ANOVA to study between groups differences for group 1 vs. group 2, group 1 vs. group 3 and group 2 vc. group 3.