title: Inherited ventricular arrhythmias and sudden death in German shepherd dogs.
abstract: OBJECTIVE
  This report describes a unique group of German shepherd dogs with inherited ventricular arrhythmias and sudden death. Before death, these dogs have no evidence of cardiovascular failure.
  
  
  BACKGROUND
  There are few spontaneous animal models of sudden death that permit intensive investigation.
  
  
  METHODS
  To determine the temporal evolution of ventricular arrhythmias and to characterize the syndrome of sudden cardiac death in these dogs, 24-h ambulatory electrocardiographic (ECG) monitoring, echocardiograms, electrophysiologic testing and breeding studies were conducted.
  
  
  RESULTS
  The 24-h ambulatory ECGs from dogs that died showed frequent ventricular arrhythmias with rapid polymorphic ventricular tachycardia (rates > 480 beats/min). Affected dogs had a window of vulnerability for arrhythmias, with the highest incidence and severity of arrhythmias between 20 to 30 and 40 to 50 weeks of age. Affected dogs that died did not have prolongation of the QT interval over a spectrum of heart rates compared with unaffected dogs. The clinical arrhythmia was not induced in dogs during programmed electrical stimulation. Severely affected dogs monitored > 5 years did not develop any evidence of heart failure or cardiomyopathy, and no histopathologic abnormalities existed. Seventeen dogs died suddenly (age 4 to 30 months) and were either 1) found dead at first observation in the morning (n = 8), 2) observed to die during sleep (n = 4), 3) observed to die while resting after exercise (n = 3), or 4) observed to die during exercise (n = 2). All sudden deaths occurred between the end of September and April, with most (n = 11) during January and February.
  
  
  CONCLUSIONS
  The cause of the inherited severe ventricular arrhythmias and sudden death in these young German shepherd dogs is still undetermined. A purely arrhythmic disorder is supported by the lack of cardiac pathology. Moreover, the window of vulnerability to ventricular arrhythmias and the age and circumstances of death invite speculation about the role of the autonomic nervous system.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853.
authors.forename: N S
authors.initials: NS
authors.lastname: Moise
authors.forename: V
authors.initials: V
authors.lastname: Meyers-Wallen
authors.forename: W J
authors.initials: WJ
authors.lastname: Flahive
authors.forename: B A
authors.initials: BA
authors.lastname: Valentine
authors.forename: J M
authors.initials: JM
authors.lastname: Scarlett
authors.forename: C A
authors.initials: CA
authors.lastname: Brown
authors.forename: M J
authors.initials: MJ
authors.lastname: Chavkin
authors.forename: D A
authors.initials: DA
authors.lastname: Dugger
authors.forename: S
authors.initials: S
authors.lastname: Renaud-Farrell
authors.forename: B
authors.initials: B
authors.lastname: Kornreich
mesh_terms: D000818:Animals; D001947:Breeding; D016009:Chi-Square Distribution; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality / Q000473:pathology; D004285:Dogs; D004452:Echocardiography / Q000706:statistics & numerical data / Q000662:veterinary; D015716:Electrocardiography, Ambulatory / Q000706:statistics & numerical data / Q000662:veterinary; D005260:Female; D006329:Heart Conduction System / Q000473:pathology; D008297:Male; D009206:Myocardium / Q000473:pathology; D010375:Pedigree; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000235:genetics / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D013997:Time Factors