title: Arrhythmogenic channelopathy syndromes presenting as refractory epilepsy.
abstract: BACKGROUND
  Children and young adults with potentially lethal cardiac channelopathies often present to medical care with a history of syncope or seizures due to episodic ventricular arrhythmias and associated cerebral hypoperfusion.
  
  
  METHODS
  Two important types of genetic arrhythmia syndromes-long QT syndrome and catecholaminergic polymorphic ventricular tachycardia-are discussed using relevant case examples. The pathophysiology and distinguishing clinical features of these conditions are reviewed.
  
  
  RESULTS
  The patients in each case were ultimately diagnosed with a cardiac channelopathy as the cause for their syncope and refractory seizures. With appropriate medical management, no further events have occurred to date.
  
  
  CONCLUSIONS
  Cardiac channelopathies can be misdiagnosed as refractory epilepsy when in fact these events represent convulsive syncopes. Knowledge of and suspicion for these arrhythmogenic conditions may expedite diagnosis and improve outcomes.
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan, USA. mhazle@wakehealth.edu
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Hazle
authors.forename: Renée A
authors.initials: RA
authors.lastname: Shellhaas
authors.forename: David J
authors.initials: DJ
authors.lastname: Bradley
authors.forename: Macdonald
authors.initials: M
authors.lastname: Dick
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Lapage
mesh_terms: D000293:Adolescent; D053447:Channelopathies / Q000150:complications* / Q000175:diagnosis; D002648:Child; D004562:Electrocardiography; D004569:Electroencephalography; D004827:Epilepsy / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008133:Long QT Syndrome / Q000150:complications*; D017180:Tachycardia, Ventricular / Q000150:complications* / Q000175:diagnosis; D000098850:Polymorphic Catecholaminergic Ventricular Tachycardia