Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy, or ARVC, is a heart muscle disease that in the majority of cases runs in families. In this disease, muscle cells in the wall of the right ventricle, the chamber that pumps blood to the lungs, gradually die and are replaced by fat and scar tissue. The wall of the right ventricle becomes thin and enlarged, and it no longer moves in a coordinated way. The scar tissue also disrupts the heart's electrical pathways, causing extra beats and fast rhythms from the ventricles.

The Cause Lies in the Genes

Many people with ARVC have changes in the genes that form desmosomes, the structures that bind one heart muscle cell to the cell next to it. Genes that are often involved include PKP2, DSP, DSG2, and DSC2. Weak bonds make the muscle cells easily damaged, especially when the heart works hard. The gene changes are usually inherited in an autosomal dominant pattern: each child of a gene carrier has about a 50 percent chance of inheriting it. However, not all gene carriers become ill, and the severity of the disease can differ between family members.

Who Is Affected and When

Symptoms usually begin between the late teens and the 40s, more often in men. Typical complaints are palpitations, dizziness, or fainting during or after exercise. In some people, cardiac arrest during activity is the first sign. ARVC is also one of the causes of sudden death in young athletes. In some people, the left ventricle is also affected, so some experts use a broader term: arrhythmogenic cardiomyopathy.

Strenuous Exercise Makes the Disease Worse

Research shows that frequent, strenuous endurance exercise brings on symptoms earlier and increases the risk of arrhythmia in gene carriers. For this reason, people with ARVC and gene carriers are advised to avoid strenuous and competitive sports. Light to moderate activity is usually still fine, as advised by your doctor.

Treatment

ARVC cannot yet be cured, but it can be controlled. Treatment aims to prevent sudden death, reduce rhythm disorders, and maintain pumping function. Options include limiting exercise, beta blockers and antiarrhythmic medicines, catheter ablation, and an implantable cardioverter defibrillator (ICD) for those at high risk. Close family members are advised to have a heart examination and genetic testing. The fast ventricular rhythms that can develop are covered on the Ventricular Tachycardia page.

No single test is enough to confirm ARVC. Doctors use international diagnostic criteria that combine several findings: abnormalities in the size and movement of the right ventricle, the appearance of the muscle tissue, ECG patterns, the type of arrhythmia, and family history and genetic test results.

Testing usually starts with an ECG and Holter monitoring to look at the electrical pattern and count the extra beats from the ventricles. Echocardiography and cardiac MRI assess the size, wall movement, and scar tissue in both the right and left ventricles. A treadmill test can reveal arrhythmias that appear during activity. In certain situations, an electrophysiology study helps distinguish ARVC from a benign tachycardia arising from the right ventricular outflow tract. A heart muscle biopsy is now rarely needed. Once the diagnosis is made, your doctor assesses the risk of serious arrhythmias to decide whether an ICD is needed.

ARVC often causes no symptoms at first, so complaints during exercise and a family history should be taken seriously. If someone faints and is not breathing normally, call emergency services at 119 right away and start chest compressions. Make an appointment with a cardiologist if:

• You have palpitations, dizziness, or near fainting during or after exercise
• You have fainted without a clear cause
• A family member has been diagnosed with ARVC or carries a gene that causes it
• A family member died suddenly before age 50
• Your ECG or Holter results show many extra beats from the ventricles