4. Patients with any of the following conditions:a diagnosis of thyrotoxicosis, a diagnosis of paroxysmal tachycardia (>100 beats per minute), a marked baseline prolongation of QT/QTc interval (e.g. repeated demonstration of a QTcF* interval > 450 ms), a history of additional risk factors for Torsade de Pointes (TdP) (e.g. heart failure, hypokalemia, family history of Long QT Syndrome)