What is ARVC?

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a disease that commonly affects Boxers but other breeds may be affected. The condition results from abnormal fat and scar tissue deposition within the heart that affects the electrical conduction, resulting in periods of abnormal fast heart beats (ventricular premature contractions, or VPCs). If there is a sustained period of fast beats together (ventricular tachycardia) this can cause decreased oxygen delivery to the brain resulting in collapse, fainting, or sudden death.

How is ARVC diagnosed?

An ECG (electrocardiogram) is required to diagnose VPCs and ventricular tachycardia. A Holter monitor (24 hour ECG vest worn at home) may be required to diagnose ARVC in some cases, and is the main tool for monitoring response to treatment once ARVC is diagnosed. An echocardiogram (ultrasound of the heart) is generally recommended to exclude other heart diseases which may predispose to VPCs. As there are many diseases that can cause VPCs, your veterinarian may recommend other diagnostic tests to screen for systemic conditions (for example bloodwork, abdominal ultrasound, chest x-rays).

What are the treatment options and prognosis?

While we are unlikely to eliminate VPCs completely, we use medications to reduce the frequency and severity of these abnormal rhythms and thereby reduce symptoms. The primary medication used is called sotalol. This medication is an anti-arrhythmic that slows heart rate and reduces VPCs. There are many other medications that may be used, and therapy is tailored to each individual based on diagnostic tests and response to treatment.

Many dogs with ARVC have good long-term prognosis, but dogs with ARVC may be at risk for disease progression that can cause symptoms and may necessitate medication adjustments. A small population of dogs with ARVC are at risk for worsening heart function leading to development of congestive heart failure (fluid build-up in the lungs or abdomen) and a more guarded prognosis. Therefore, once a patient is diagnosed with ARVC, we recommend periodic follow-up visits with a cardiologist throughout their lives.