Snapshot A 15-year-old girl presents with palpitations and dizziness. She has had similar episodes in the past but has never needed to go to a hospital. Her family history includes sudden cardiac death in her father and congenital sensorineural deafness in multiple family members. An echocardiogram reveals a sinusoidal waveform concerning for torsades de pointes. (Jervell and Lange-Nielsen syndrome) Introduction Clinical definition login to view 1 more bullet Epidemiology login to view 6 more bullets Etiology login to view 8 more bullets Pathogenesis login to view 3 more bullets Associated conditions login to view 7 more bullets Prognosis login to view 2 more bullets Presentation Symptoms login to view 5 more bullets Physical exam login to view 2 more bullets Studies Labs login to view 1 more bullet Electrocardiogram (ECG) login to view 6 more bullets Making the diagnosis login to view 1 more bullet Differential Supraventricular tachycardia login to view 2 more bullets Treatment Conservative login to view 5 more bullets Medical login to view 13 more bullets Operative login to view 4 more bullets Complications Ventricular fibrillation