Mode of onset of torsade de pointes in patients with congenital long QT syndrome and documented arrhythmias2-151
| Pause dependent arrhythmias | Non-pause dependent arrhythmias | |
| Number of patients | 46 (74%) | 16 (26%) |
| Age (SD) in years2-152 2-153 | 27 (16)2-150 | 5 (7) |
| Infants (⩽ 3 years old)2-153 | 1 (2%)2-150 | 8 (53%) |
| Females2-153 | 33 (80%)2-150 | 7 (54%) |
| Deafness2-153 | 3 (7%) | 3 (21%) |
| Mean (SD) QTc (ms) | 569 (77) | 620 (49) |
| Mean (SD) QT score77 | 5.4 (0.6) | 5.6 (0.8) |
| Stress related arrhythmias | 26 (79%) | 14 (100%)2-152 |
| No β blocker treatment2-153 | 35 (79%) | 12 (86%) |
↵2-150 p < 0.05.
↵2-151 Data from all patients shown in table 1.
↵2-152 All in-hospital arrhythmias in newborns were presumed to be stress related. For older patients, a history of out-of-hospital syncope or cardiac arrest following physical or emotional stress (including sudden arousal) was used as evidence for stress related arrhythmias (data were not available for 15 patients reported by others).
↵2-153 Data on age, sex, history of deafness, and number of patients receiving treatment at the time of arrhythmia documentation was not available for 5, 6, 7 and 4 patients published by others, respectively.