7. Patients with pre-existing QT prolongation (including congenital long QT syndrome) or receiving other QT prolonging drugs (including Class Ia—e.g., quinidine, Class III—e.g., dofetilide, sotalol, antiarrhythmics; antipsychotics (e.g., thioridazine, ziprasidone), or known history of complex ventricular arrhythmias requiring antiarrhythmic medications or ICD implantation.