are not used in patients with congenital or acquired long QT syndrome unless there is no suitable alternative or the benefit greatly exceeds the risk. Episodes of torsades de pointes can be precipitated by exposure to a QT-prolonging medi- cation, and underlying prolongation of the QT (from genetic and clinical risk factors) increases Medications implicated in torsades de pointes are found in several medication classes, including antiarrhythmics, antihistamines, antibi- otics, antifungals, antidepressants, antipsychotics, opiates, and anticancer agentsS10.7-10 (Table 10). 10.8. Adult Congenital Heart Disease Recommendations for Adult Congenital Heart Disease References that support the recommendations are summarized in Online Data Supplement 54. 