A History of Drug-Induced Torsades de Pointes Is Associated With T-wave Morphological Abnormalities

The hypothesis of the study is that Torsades de pointes (TdP) history can be better identified using T-wave morphology compared to Fridericia-corrected QT interval (QTcF) at baseline. ECGs were recorded at baseline and during sotalol challenge in 20 patients with a history of TdP (+TdP) and 16 patients without previous TdP (–TdP). The QTcF and T-wave morphology combination score (MCS) were calculated. At baseline, there was no significant difference in QTcF between the groups (+TdP: QTcF = 446 ± 9 ms; –TdP: QTcF = 431 ± 9 ms, P = 0.27). In contrast, MCS was significantly different between the groups at baseline (+TdP: MCS = 1.07 ± 0.095; –TdP: MCS = 0.74 ± 0.07, P = 0.012). Both QTcF and MCS could be used to discriminate between +TdP and –TdP after sotalol but only MCS reached statistical significance at baseline. Combining QTcF with MCS provided a significantly larger difference between groups than QTcF alone.