Arrhythmogenic Right Ventricular Dysplasia (ARVD) or Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is a hereditary cardiomyopathy (heart muscle disease) in which ventricular muscle cells are gradually destroyed and replaced by fibrous fatty tissue. This disease can also affect the left ventricle or both.
ARVD leads to an increased risk of developing a heart rhythm disorder (arrhythmia) such as tachycardia or ventricular fibrillation and can progress to heart failure.
The disease mainly affects men and is aggravated by the regular practice of intense, high-level sports. Diagnosing this condition is a complex process requiring multiple tests.
Consequences
The main consequences of ARVD are:
- heart rhythm disorders that may manifest as episodes of ventricular tachycardia, potentially progressing to ventricular fibrillation and sudden cardiac death, which can be fatal if not treated promptly,
- heart failure primarily affecting the right ventricle but which may progress to the left ventricle,
Causes
ARVD is a genetic condition inherited in an autosomal dominant pattern. In other words, only one copy of the altered gene is needed for the disease to develop. Parents therefore pass on the affected gene to their children with a 50% chance of each child inheriting the disease. There are no genetic differences between men and women, but men are at a higher risk of developing the disease. A rare form of the disease, called Nexos, associates ARVD with other physical symptoms, such as abnormal thickening of the skin (hyperkeratosis) and woolly hair.
In 70% of ARVD cases, the genetic mutations responsible for the disease are known. They are primarily genes involved in producing the proteins that play an essential role in the junctions between cardiac muscle cells.
Symptoms
The disease is most often asymptomatic until the onset of heart rhythm disorders, which occur before the age of 40 in 80% of cases. ARVD can cause the following arrhythmias:
- ventricular extrasystoles (the heart beats more than necessary), which are isolated or repetitive,
- ventricular tachycardia (sustained increase in heart rate) occurring spontaneously or during physical activity.
These arrhythmias lead to palpitations, dizziness or loss of consciousness. Ventricular fibrillation can lead to sudden cardiac death, which can be fatal. There is a greater risk of sudden cardiac death during intense physical exertion.
Diagnosis
Diagnosing ARVD requires a wide range of tests to analyze clinical signs, the heart’s morphology and its electrical activity. Diagnosis is often difficult in the early stages or when atypical signs are present.
The main examinations that can be performed are:
- Electrocardiograms (ECG) record the heart’s electrical activity to identify characteristic signs of the disease,
- Holter monitor tests continuously analyze the heart’s electrical activity for 24 hours to detect intermittent heart rhythm disorders.
- Cardiac stress tests involve recording the heart’s electrical activity with an ECG during physical activity to trigger a rhythm disorder,
- High-amplification electrocardiography (HA-ECG) reveals slow electrical conduction areas in the heart muscle, an ultrasound is primarily used to rule out other types of cardiomyopathy. It is often used during the early stages of the disease but can also detect a dilated and strained right ventricle at an advanced stage of ARVD.
- Magnetic resonance imaging (MRI) analyzes the contractile activity of the heart and the structure of the myocardial wall (presence of fibrous and fatty deposits),
- programmed ventricular stimulation involves triggering a ventricular rhythm disorder by introducing a venous catheter into the right ventricle,
- genetic screening to identify mutations associated with ARVD.
Genetic screening is also suggested for relatives of people with ARVD, starting at the ages of 10-12, and is conducted every 1 to 3 years.
Treatment
The proposed treatments aim to treat the symptoms of ARVD and prevent complications. Treatment varies depending on the severity of the disease. Treatment options include:
- hygienic-dietary measures including exercise,
- medication, with the prescription of beta-blockers and/or antiarrhythmics,
- a cardioverter-defibrillator can be implanted for patients who have experienced ventricular arrhythmias or sudden cardiac death or to protect patients with a high risk of ventricular arrhythmia,
- heart failure treatment depending on the progression of the disease.
Reviewed and approved by Frédéric Sacher, Professor, MD, PhD, Cardiologist at Bordeaux University Hospital (CHU)
