Boxer arrhythmogenic right ventricular cardiomyopathy (ARVC) is a disease that may result in sudden death or heart failure.Hypothesis/objectives:
To prospectively study the natural history of Boxer ARVC.Animals:
72 dogs (49 ARVC, 23 controls).Methods:
Boxers >1 year of age were recruited for annual reevaluation. Controls were defined as being ≥6 years of age and having <50 ventricular premature complex (VPCs)/24 h. ARVC was defined as ≥300 VPCs/24 h in the absence of other disease. Dogs were genotyped for the striatin deletion when possible. Descriptive statistics were determined for age; VPC number; annual change in VPC number; and left ventricular (LV) echocardiographic dimensions. Survival time was calculated.Results:
Controls: median age of 7 years (range, 6–10); number of VPCs 12 (range, 4–32). Median time in study of 6 years (range, 2–9). Seventeen of 23 were genotyped (5 positive, 12 negative).Results:
ARVC: median age of diagnosis of 6 (range, 1–11). Median time in study 5 years (range, 3–8). A total of 33% were syncopal and 43/49 were genotyped (36 positive, 7 negative). Yearly change in VPCs was 46 (range, −7,699 to 33,524). Annual percentage change in LV dimensions was 0, and change in fractional shortening (FS%) was 2%. Two dogs had FS% <20%. Although ARVC dogs died suddenly, there was no difference in survival time between groups. ARVC median age of survival was 11 years, and for controls was 10 years.Conclusions/Clinical Importance:
Arrhythmogenic right ventricular cardiomyopathy is a disease of middle age and frequently is associated with the striatin deletion. Syncope occurs in approximately 1/3 of affected dogs; systolic dysfunction is uncommon. The prognosis in many affected dogs is good.