title: True-true, unrelated: a case report.
abstract: OBJECTIVE
  Sudden cardiac deaths in previously healthy children are frequently due to undiagnosed cardiovascular diseases, either congenital or acquired. In an uncommon clinical entity known as commotio cordis, sudden death from cardiac arrest can occur in young athletes after a blunt blow to the chest, in the absence of preexisting cardiovascular disease. We present a case in which the clinician's high index of suspicion leads to the diagnosis of acute myocarditis in a patient whose sudden cardiac deterioration was initially attributed to the result of recent blunt chest trauma.
  
  
  METHODS
  A case report and review of literature via MEDLINE (1996-2004) search using the key words "myocarditis," "commotio cordis," and "myocardial contusion."
  
  
  RESULTS
  A 12-year-old boy was admitted with elevated cardiac enzymes and respiratory distress after being hit in the chest with a dodgeball. Shortly after admission, the patient developed refractory ventricular arrhythmia, which was thought to be the result of blunt chest trauma. Further evaluation with endomyocardial biopsy, however, demonstrated acute myocarditis as the true etiology, for which the patient received immunosuppressive treatment. Unfortunately, the patient eventually required cardiac transplantation because of progressive irreversible cardiac dysfunction due to myocarditis.
  
  
  CONCLUSIONS
  Although acute myocarditis, commotio cordis, and myocardial contusion can all present with malignant ventricular arrhythmia, other clinical features and approaches to management of each disease are very different. This case illustrates the importance of having a broad differential diagnosis in mind when presented with a previously healthy child in sudden cardiogenic shock.
authors.affiliation: Division of Pediatric Critical Care, Department of Pediatrics, Mattel Children's Hospital, University of California, Los Angeles, CA, USA. dhsing@mednet.ucla.edu
authors.forename: Deyin D
authors.initials: DD
authors.lastname: Hsing
authors.forename: Andranik
authors.initials: A
authors.lastname: Madikians
mesh_terms: D000208:Acute Disease; D001265:Athletic Injuries / Q000150:complications*; D001706:Biopsy; D006328:Cardiac Catheterization; D006332:Cardiomegaly / Q000209:etiology; D002637:Chest Pain / Q000209:etiology; D002648:Child; D003288:Contusions / Q000175:diagnosis*; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D004417:Dyspnea / Q000209:etiology*; D015199:Extracorporeal Membrane Oxygenation; D006323:Heart Arrest / Q000209:etiology*; D006335:Heart Injuries / Q000175:diagnosis*; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D009205:Myocarditis / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D009206:Myocardium / Q000473:pathology; D011654:Pulmonary Edema / Q000209:etiology; D017180:Tachycardia, Ventricular / Q000209:etiology; D013898:Thoracic Injuries / Q000150:complications*