Outcome of young dogs with unexplained heart rhythm problems

Abstract

INTRODUCTION/OBJECTIVES: Juvenile ventricular arrhythmias in the absence of structural heart disease have been characterized in a small number of canine breeds with limited long-term follow up. The objective of this study was to describe the clinical outcome of dogs with JVA presenting to a university teaching hospital. ANIMALS, MATERIALS, METHODS: Twenty five dogs, less than two years old with idiopathic ventricular arrhythmias were retrospectively identified via a medical record search. Young dogs with ventricular arrhythmias were excluded if they had structural heart disease, systemic illness, or an abnormal troponin (if performed). Electrocardiographic and Holter monitor data was evaluated for arrhythmia frequency and complexity at the time of diagnosis and over time. Long-term follow up was achieved through client and primary veterinarian contact. RESULTS: Breeds included German Shepherd (eight), Boxer (four), Great Dane (three), mixed breed (two) and one each of the following: Anatolian Shepherd, French Bulldog, golden retriever, Great Pyrenees, Labrador retriever, Shiloh Shepherd, miniature Poodle and Siberian Husky. The average age at diagnosis was 7.9 months (range, 2-22 months). The overall median survival was 10.96 years (range, 1.75-15.66 years). There was an average reduction in the number of ventricular beats by 86.7 % per year (P value -0.0257) based on Holter data. CONCLUSION: In most cases, idiopathic juvenile ventricular arrhythmias had a favorable long-term prognosis with reduced ectopy over time in this case series. Juvenile ventricular arrhythmias remains a diagnosis of exclusion but can be considered in a broader range of dog breeds than previously described.