[Amiodarone therapy after sotalol-induced torsade de pointes: prolonged QT interval and QT dispersion in differentiation of pro-arrhythmic effects].

In a 70-year-old patient with sotalol-induced torsade de pointes, QT-dispersion in the 12-lead surface ECG was determined in an attempt to evaluate the role of this method in determining risk factors for the development of proarrhythmic effects. After recovery from torsade, the patient was successfully treated with amiodarone over a 3-month follow-up period. Whereas the degree of QT prolongation was comparable during amiodarone therapy to that observed with sotalol, QT dispersion was markedly less (47 ms) than during previous treatment with sotalol (77 ms). During drug-free control, QT dispersion was 43 ms. This case-report indicates that determination of QT dispersion can provide information with respect to identification of patients prone to class III antiarrhythmic drug-induced proarrhythmic effects.