Asymptomatic adult (male) long QT syndrome patients with normal QTc intervals may choose to decline beta-blocker 7. The risk of adverse cardiac events from VA is influenced by the patient s resting QTc inter- val, age, sex, and long QT syndrome genotype/ mutation. For asymptomatic males with long QT syndrome, the risk of cardiac events is highest in during a time when medication compliance is challeng- ing. Young women with LQT2 and QTc >500 ms are at increased risk of SCAS7.9.1.1-2,S7.9.1.1-11, especially in the 9 months postpartum, and may be candidates for primary prevention ICD placement or use of a 8. The risk of adverse events increases in patients with long QT syndrome with prolongation of the QTc QT-prolonging medications (www.crediblemeds. should not be used in patients with long QT syndrome unless there is no suitable alternative; careful monitoring of the QTc during therapy is recommended, with consideration for discontinuing therapy with marked QTc prolonga- tion. Concurrent use of stimulant or nonstimu- lant attention deficit/hyperactivity medications was associated with an increased risk of syncope/ cardiac arrest in long QT syndrome, particularly but it did not appear to be associated with increased risk in another ret- Episodes of torsades de pointes can be precipitated by exposure to a QT prolonging medication, or hypokalemia induced by diuretics or gastrointestinal illenss. Attention to maintaining normal potassium and magne- sium balance when medications or situations CLINICAL STATEMENTS AND GUIDELINES that promote depletion are encountered is an important component of management. Rare case reports exist of fever prolonging the QT interval in patients with long QT syndrome type 2; fever should be reduced with antipyreticsS7.9.1.1-61 (Table 10). 7.9.1.2. Catecholaminergic Polymorphic Ventricular Tachycardia Recommendations for Catecholaminergic Polymorphic Ventricular Tachycardia References that support the recommendations are summarized in Online Data Supplement 41. 