title: Significance of appropriate defibrillator shock 3 hours and 20 minutes following implantation in a patient with hypertrophic cardiomyopathy.
abstract: BACKGROUND
  Implantable defibrillators have proved effective in terminating potentially life-threatening ventricular tachyarrhythmias in hypertrophic cardiomyopathy (HCM), although the timing of appropriate shocks may be exceedingly variable.
  
  
  RESULTS
  We report an unusual occurrence in a 48-year-old woman with nonobstructive HCM who experienced an appropriate shock for ventricular fibrillation only 3 hours and 20 minutes after implantation. Careful review of the clinical circumstances failed to define a specific mechanism related to the implant procedure that could have triggered the potentially lethal arrhythmia.
  
  
  CONCLUSIONS
  Early device interventions are not uncommon in HCM, but (as in this case) appear unrelated to mechanisms other than the unpredictable and underlying arrhythmogenic substrate in this disease.
authors.affiliation: Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, Minnesota 55407, USA.
authors.forename: Adrian K
authors.initials: AK
authors.lastname: Almquist
authors.forename: Constance A
authors.initials: CA
authors.lastname: Hanna
authors.forename: Tammy S
authors.initials: TS
authors.lastname: Haas
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Maron
mesh_terms: D002312:Cardiomyopathy, Hypertrophic / Q000150:complications* / Q000628:therapy*; D017147:Defibrillators, Implantable; D005260:Female; D006801:Humans; D008875:Middle Aged; D011184:Postoperative Period; D019919:Prosthesis Implantation; D017180:Tachycardia, Ventricular / Q000209:etiology* / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome