Long QT syndrome (LQTS) is characterized by episodes of fainting or by sudden death as a result of torsades de pointes (TdP). In both the congenital and acquired forms of the syndrome, symptoms often become manifest upon exposure to additional clinical stressors of repolarization, such as drugs or hypokalemia.
We report here the case of a patient with congenital LQTS in a 6-year-old boy who manifested symptoms only in the presence of electrolyte abnormalities associated with the inherited salt-wasting renal disorder Gitelman syndrome. In this case, a second distinct congenital disorder modified the clinical presentation of LQTS.