What is ARVC?
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart muscle problem. Relatively rare, it affects up to 1 in 10,000 of the population. The condition is due to a mutation (‘spelling’ mistake) in the genes that code for the structure and function of the heart. Fat and scarring accumulate within the heart muscle, causing the electricity and/or the heart's ability to pump blood to be affected.
Generally ARVC affects the right ventricle (pump chamber), however, the left ventricle may also be involved. Occasionally the condition spares the right side and predominantly affects the left side. Only the lower, blood pumping chambers of the heart are affected. Dr Amanda Varnava talks more about the symptoms and diagnoses of ARVC.
What symptoms do patients with ARVC have?
Patients with ARVC may present with symptoms predominantly related to the rhythm of the heart.
These can include:
- Palpitations; a feeling that the heart is fluttering or beating too fast. This is caused by an irregular heartbeat or arrhythmias. Arrhythmias occur when the electrical pathways that control how the heart beats are disrupted.
- Dizziness or collapse; arrhythmias can cause reduced oxygen and blood flow to the brain, causing a person to feel faint, and may even lead to a loss of consciousness.
- Swollen tummy, legs and ankles; fluid can build up in these areas, if the heart isn’t pumping blood correctly, also known as oedema.
- Breathlessness ( dyspnoea ) and chest pain; these symptoms are less common.
Day to day, most patients have little in the way of symptoms, so it is entirely possible to harbour the condition without any awareness of having it. It is even possible to have ARVC and be capable of undertaking high-level sports.
How is the diagnosis made?
ARVC may be diagnosed after symptoms present. However, for some individuals without symptoms, an abnormal ECG undertaken for screening purposes may highlight a problem.
The ECG may be done as part of a routine assessment, sports assessment or as part of a family screening if a first-degree relative is found to have the condition. The ECG looks at the electrical activity of the heart and can reveal whether the electrical impulse is normal as it passes through the heart.
Sometimes test results show the disease very clearly, but often the diagnosis may require several different tests. This is because there are different phases of the disease. During the early phase, only mild changes in the heart may be detected. Despite these mild changes, there can still be a risk.
Electrical testing of the heart can be undertaken over a 24 hour period using a Holter monitor and during exercise (exercise ECG test). A Holter device can be worn around the waist or placed in a pocket and looks at the electrical activity (heartbeat) of the heart for an extended period. Together these tests may give a picture compatible with definite, probable or possible disease.
Unfortunately, some of the changes that are found in the heart muscle can occur quite commonly as a benign response to sports training (such as minor ECG changes or ventricular ectopics/skipped beats). It is therefore important that anyone interpreting an athlete’s ECG is aware of this overlap.
Managing the condition
Although there is no cure for ARVC, symptoms of the condition can be managed and the risk of complications such as cardiac arrest and collapse can be reduced.
Some treatments to control arrhythmias include the following:
- Antiarrhythmic medication; to control abnormal heartbeats and help the heart to beat at the correct pace
- Anticoagulants or blood thinners; to reduce the risk of blood clots that could lead to stroke
- ACE inhibitors; to relax the blood vessels in the heart, so the heart doesn’t have to work so hard
- Implantable defibrillator; this may be used if a person's heart is beating too fast, to normalize the hearts rhythm
- Catheter ablation; radio waves stop the electrical signals in the heart that cause an abnormal heartbeat
ARVC can be a very serious condition, as it can lead to complications, like heart failure and sudden cardiac arrest. If you are experiencing any of the symptoms mentioned above, tell your doctor right away and they can transfer you to a specialist for further examination if required.