Arrhythmogenic Right Ventricular Dysplasia

Arrhythmogenic right ventricular cardiomyopathy (ARVC), Arrhythmogenic cardiomyopathy (ACM), Right ventricular dysplasia

Arrhythmogenic right ventricular dysplasia is a rare heart condition where normal heart muscle is replaced by fat or scar tissue, potentially causing life-threatening irregular heartbeats, especially in young people and athletes.

Table of contents

• What is arrhythmogenic right ventricular dysplasia?
• Causes and genetic factors
• Who is at risk?
• Signs and symptoms
• How doctors diagnose the condition
• Treatment options
• Outlook and prevention

What is arrhythmogenic right ventricular dysplasia?

Arrhythmogenic right ventricular dysplasia (ARVD) is a disease of the heart muscle where normal tissue is replaced by fatty or fibrous (scar) tissue. This condition primarily affects the right ventricle, which is the heart chamber responsible for pumping blood to the lungs. However, the left ventricle and the area between the two ventricles can also be affected.^[1][3]

When fat or scar tissue replaces healthy heart muscle, the right ventricle stretches out, becomes thin, and contracts poorly. As a result, the heart cannot pump blood as efficiently, making it hard to breathe and potentially causing fainting or heart fluttering.^[1]

The fatty or fibrous tissues can interfere with the heart’s electrical signals, causing abnormal heart rhythms called arrhythmias. These irregular heartbeats increase the risk of sudden cardiac arrest or death, which is why early diagnosis and treatment are so important.^[1]

This condition occurs in about 1 in 2,000 to 1 in 5,000 people, though some populations have higher rates. After hypertrophic heart disease, ARVD is the leading cause of sudden cardiac death in young people, particularly athletes, accounting for up to 10 percent of sudden cardiac deaths in people younger than 65 years.^[4][5]

Causes and genetic factors

A genetic variation is the most common cause of arrhythmogenic right ventricular dysplasia. Experts have identified at least 13 genes with variations that can cause this condition.^[1]

These abnormal genes damage proteins that help heart muscle cells connect to each other and communicate properly. Because of this, heart muscle cells in the right ventricle can separate and die. This process can happen more often during times of stress or physical exertion.^[1]

The disease can be inherited in different ways. Most commonly, it follows an autosomal dominant pattern, meaning one parent has a genetic variant and their children have a 50 percent chance of inheriting the condition. However, symptoms and age of onset can differ between family members.^[1]

Less commonly, the condition follows an autosomal recessive pattern, where both parents carry the genetic variant but do not have symptoms. One form called Naxos disease may cause thick skin on the palms of hands and soles of feet, along with thick, wool-like hair.^[1]

A family history of ARVD is present in up to half of all cases. This is why healthcare providers recommend that all first-degree relatives (parents, siblings, children) and second-degree relatives (grandchildren, uncles, aunts, nephews, nieces) of someone with ARVD be checked for the condition, even if they have no symptoms.^[1]

Who is at risk?

Healthcare providers typically see arrhythmogenic right ventricular dysplasia in teenagers or young adults. Most diagnoses occur in people between age 20 and 40, though symptoms may start before age 40 or as early as the teenage years.^[1]

The condition affects males more often than females. It is particularly significant among young athletes, as ARVD is one of the main reasons some young athletes experience sudden cardiac arrest.^[1]

Having a relative with ARVD is the strongest risk factor for developing the disease. A parent with an abnormal gene has a 50 percent chance of passing that gene to their child. If someone in your family has ARVD, genetic testing can help determine if you are at risk.^[6]

Physical activity can trigger or worsen symptoms in people with ARVD. The disease often manifests more frequently in active individuals, and symptoms commonly present during exercise.^[7]

Signs and symptoms

Many people with arrhythmogenic right ventricular dysplasia may not have symptoms early on. However, there is still a risk of sudden cardiac death even without warning signs, and this can sometimes be the first indication of the disease.^[1]

The condition causes symptoms due to ventricular irregular heartbeats or sustained ventricular tachycardia (a fast heart rhythm starting in the lower chambers). Symptoms are often triggered by physical exercise.^[4]

Common symptoms of ARVD include:^[1]

• Heart palpitations or fluttering sensations in the chest
• Dizziness or lightheadedness
• Fainting
• Fatigue
• Chest pain
• Shortness of breath
• Swelling in legs, ankles, feet, or belly
• Irregular heartbeats, particularly atrial fibrillation

As the disease progresses, surviving patients may develop signs of right ventricular failure, which can advance to severe failure affecting both ventricles and dilated cardiomyopathy. Over time, the heart cannot pump as much blood forward as it normally would, causing fluid to back up in the circulatory system and build up in soft tissues or lungs, leading to heart failure.^[4][6]

How doctors diagnose the condition

Diagnosing arrhythmogenic right ventricular dysplasia can be difficult because the condition varies considerably in how it presents. Diagnosis relies on a combination of clinical, electrocardiographic, and imaging features.^[13]

The diagnosis is based on criteria that include ventricular structural and functional changes, abnormalities on electrocardiogram (ECG), arrhythmias, and family and genetic factors. The revised 2020 criteria recognize the importance of symptoms affecting both ventricles and the left side of the heart.^[3]

Several tests and procedures help confirm the diagnosis:

Electrocardiogram (ECG) findings may show specific patterns in people with ARVD. About 85 percent of patients have T wave inversion in right precordial leads (V1-3) without right bundle branch block. An epsilon wave, the most specific finding, appears in about 50 percent of patients. Other features include localized widening of the QRS complex, prolonged S wave upstroke, and frequent ventricular ectopic beats.^[4]

Echocardiography is usually the first imaging test performed. It may show a dilated, poorly functioning right ventricle with prominent structures at the apex and widening of the right ventricular outflow tract.^[4]

Cardiac magnetic resonance imaging (MRI) has emerged as the preferred imaging method in many centers. It can accurately show fibrofatty infiltration and thinning of the right ventricular muscle, aneurysms, dilation, regional wall motion problems, and overall dysfunction.^[4][5]

Genetic testing is essential to identify at-risk individuals, as cardiac arrest can be the first sign of ARVD. Genetic test results can guide treatment, help identify at-risk or affected family members, and inform future family planning.^[3]

Other diagnostic tools include 24-hour Holter monitoring to detect arrhythmias, right ventriculography, and in some cases, endomyocardial biopsy to obtain a definitive diagnosis, though this is impractical for routine use.^[7]

Treatment options

The goal of treating arrhythmogenic right ventricular dysplasia is to reduce mortality, prevent disease progression, improve symptoms and quality of life, limit heart failure symptoms, and improve functional capacity. Treatment is tailored to each patient based on their characteristics, genetic profile, disease severity, and symptoms.^[8]

Lifestyle modifications

People with ARVD are generally advised to avoid extreme physical activity and competitive sports, as these can increase the risk of sudden cardiac arrest and arrhythmias. Moderate exercise is often recommended, along with dietary changes to maintain a healthy weight and manage risk factors like high blood pressure and abnormal cholesterol levels.^[14]

Medications

Beta-blockers are generally considered the first line of drug therapy and are recommended in patients with recurrent ventricular tachycardia. These medications help suppress irregular heartbeats triggered by stress hormones.^[8]

For patients with more serious or recurring arrhythmias, other antiarrhythmic drugs may be used. Currently, sotalol is the most effective drug for this condition. Amiodarone and propafenone may be used alone or in combination with variable success in persistent cases.^[4][5]

For patients developing heart failure, medications such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) can help prevent adverse changes in the ventricles and manage heart failure symptoms.^[14]

Implantable cardioverter-defibrillator

An implantable cardioverter-defibrillator (ICD) is recommended for preventing sudden cardiac death in patients with sustained ventricular tachycardia or ventricular fibrillation, and for primary prevention in high-risk patients. The ICD can detect and terminate life-threatening arrhythmias to prevent sudden cardiac death.^[8][13]

High-risk factors that may warrant ICD placement include a history of cardiac arrest, recurrent arrhythmias not controlled by medications, unexplained fainting, family history of cardiac arrest in first-degree relatives, induced ventricular tachycardia during testing, severe right ventricular dilation, extensive right ventricular involvement, and left ventricular involvement.^[4][8]

ICD placement is the only treatment proven to reduce mortality in ARVD patients.^[13]

Catheter ablation

For patients with persistent symptomatic arrhythmias that do not respond to medications, radiofrequency ablation may be performed. This procedure targets specific areas causing irregular heartbeats. However, effectiveness varies, and more research is needed to determine long-term success rates.^[5][14]

Surgery

In severe cases with drug-refractory arrhythmias or advanced heart failure, surgical options may include ventriculotomy or even cardiac transplantation.^[5]

Outlook and prevention

Arrhythmogenic right ventricular dysplasia is a progressive disease that can lead to sudden cardiac death if not treated appropriately. The progression varies from person to person—some may have minor problems with few symptoms, while others experience quickly deteriorating heart function and life-threatening arrhythmias.^[14]

Factors that influence disease progression include genetic factors, environmental triggers, and other health conditions like obesity and high blood pressure. Most cases progress over years to decades, with the worst outcomes occurring in those with advanced disease.^[14]

The prognosis is worse in patients with left ventricular involvement.^[7]

Getting screened early for ARVD is the best way to reduce risk if a relative has the condition. Noninvasive tests can determine if you are at risk of abnormal heart rhythms. If at risk, your healthcare provider can work with you to create a treatment plan.^[1]

Because of the genetic nature of this disease, all first- and second-degree family members of someone diagnosed with ARVD should be evaluated by a healthcare provider, even without symptoms. Genetic testing may help identify those at risk and guide family screening and future family planning.^[1]