Table 2.
ECG characteristics of the study patients during hydroxychloroquine treatment
| All patients (n = 819) | QTc ≤470 ms (n = 752) | QTc 471–500 ms (n = 55) | QTc >500 ms (n = 12) | P value∗ | |
|---|---|---|---|---|---|
| Ventricular rate (bpm) | 74.8 ± 17.3 | 74.1 ± 17.0 | 80.9 ± 16.5 | 85.4 ± 25.7 | .001 |
| QRS duration (ms) | 100.9 ± 22.8 | 101.0 ± 23.2 | 98.3 ± 16.3 | 104.0 ± 24.2 | .47 |
| QT interval (ms) | 392.8 ± 44.5 | 389.6 ± 42.6 | 421.3 ± 40.0 | 462.6 ± 73.6 | <.0001 |
| QTc-Bazett (ms) | 430.9 ± 31.8 | 425.5 ± 26.2 | 481.6 ± 7.9 | 535.3 ± 39.0 | <.0001 |
| QTc-Framingham (ms) | 417.8 ± 30.3 | 413.3 ± 27.3 | 457.3 ± 15.9 | 491.5 ± 45.7 | <.0001 |
| QTc-Fridericia (ms) | 418.1 ± 30.5 | 413.4 ± 27.2 | 460.2 ± 13.3 | 494.2 ± 49.4 | <.0001 |
Continuous variables are given as mean ± SD.
ECG = electrocardiogram.
∗
Comparison of QTc ≤470 ms vs QTc >470 ms.