Arrhythmogenic right ventricular cardiomyopathy in the Boxer dog: Updates on diagnosis and treatment

Abstract

The arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited myocardial disease commonly observed in the adult Boxer, characterized by the replacement of right ventricle (RV) cardiomyocytes by fibrofatty tissue, what generate areas prone to the formation of ventricular arrhythmias, which may culminate in sudden death. Due to advances in genetic mapping in domestic dogs, it could be concluded that Boxers are affected by ARVC in a closed related way to human beings, and therefore are considered a natural animal model for the study of human ARVC. There is not a single and specific diagnostic test for ARVC, thus, in veterinary practice the diagnosis is best based on a combination of findings, which may include the presence of ventricular tachyarrhythmia with no other documented causes for the arrhythmia, as well as syncope, and family history to ARCV. Treatment is directed to decrease the occurrence and the complexity of the ventricular arrhythmias, and sotalol and/or mexiletine are the antiarrhythmics most commonly prescribed, as well as omega 3 from fish oil. However, it is unknown if the treatment on an asymptomatic dog prolongs survival. Although some affected dogs show sudden death or develop congestive heart failure, many of them have ventricular arrhythmias that are controllable by antiarrhythmics and live a normal life. Some characteristics of ventricular premature complexes, as polymorphism and ventricular tachycardia, the presence of clinical signs, and systolic dysfunction of left and right ventricles are associated with worst prognosis.