Arrythmogenic Right Ventricular Cardiomyopathy information sheet
What is Arrythmogenic Right Ventricular Cardiomyopathy?
Arrhythmogenic
Right Ventricular Cardiomyopathy or Dysplasia (ARVC or ARVD) is an inherited
condition that affects the muscle of the right ventricle (one of two main
pumping chambers that make up the heart). The
right ventricle mays become progressively more unable to function efficiently
due to muscle cells being replaced by fatty deposits and fibrosis.
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In
order to fully explain the condition it is necessary to explain the parts
of the heart and the function performed by the right ventricle.
As previously mentioned the heart contains two main pumping
chambers the ventricles which are primed (or filled) by two chambers at
the top of the heart called the atria.
The left ventricle fills with blood
(fully oxygenated from the lungs) and pumps this blood filled with
oxygen to the brain and body.
The right ventricle pumps blood to the lungs, were wastes are removed (by breathing them out) and fresh oxygen is added to the blood by (breathing in). Oxygen that is required by all body cells is then returned to the heart, and pumped around the body by the Left Ventricle. |
The
words arrythmogenic right ventricular cardiomyopathy(ARVC), in simple terms
means that the right ventricular heart muscle is affected by a condition that
can cause the heart to have erratic and sometimes very fast heart beats.
In order to understand these words it is easier to break them down for
instance, ’cardio’ is another word which describes the heart and
‘myopathy’ means a condition or problem related to muscle.
The word ‘arrythmogenic’ describes how the condition normally
presents itself, which is through very fast heart rhythms that usually cause
people to fell dizzy or collapse, or cause a cardiac arrest.
An arrhythmia means an abnormal heart rhythm.
The arrhythmia may occur suddenly and without any prior symptoms or
warning.
As
ARVC progresses healthy muscle cells are replaced with fatty infiltrate and
fibrotic bands. The normal
elasticity of the right ventricular muscle is lost, as are it’s strength and
ability to pump blood efficiently.
The incidence of ARVC is thought to be relatively rare, with approximately 1 in every 5000 people being affected. Since the condition is hereditary, that means it can run in families (30 – 50%) of cases it is recommended that parents and brothers sisters and the children of those affected should be screened. Although ARVC has been found to be an important cause of sudden death in young fit athletes, however people from all ages, races and activity levels can carry the condition, and it typically occurs in adult young men.
Families with two or more affected
individuals have been found in a number of countries, such as North America,
Italy, Japan, Africa, and Northern Europe, Australia and New Zealand.
Symptoms
Sometimes people may be completely asymptomatic, that is they have no symptoms at all as often the first symptom may be collapse or sudden death.
Other people may have symptoms of an erratic heartbeat (palpitations or a racing heart beat) occasionally as their only symptoms. Patients with ARVC usually present with some type of symptom prior to age 45, but often present in late puberty or before age 30.
Diagnosis
of ARVC
ARVC
was first characterised by Dr’s Marcus and Fontaine in 1982. Since then a
number of important diagnostic criteria that can help doctors to make the
diagnosis of ARVC have been developed.
There is no single diagnostic test to establish or exclude the diagnosis of ARVD. Currently doctors will utilise many available tests in order to diagnose it. An ECG (electrocardiograph) is a recording of the heart rhythm and this may produce some signs of ARVC (other ECG based testing may included 24 hr Holter recordings and Exercise treadmill tests), however an ECG is never used in isolation to make a diagnosis.
Electrophysiology studies which attempt to provoke abnormal heart rhythms and see where they arise from is one test which may be performed (this test is performed in hospital by a specialist cardiologist).
Magnetic resonance imaging, a special highly specific scan, can provide a superior view of the right ventricle, and although it is a new technique it is proving to be very useful in this condition. Echocardiography, utilises an ultrasound beam to image the heart, may prove to be useful in some cases. Other studies including right heart catheterisation, in this test, a contrast dye is injected into the right heart as it pumps so that abnormalities can be to view the right ventricle and a during this biopsy samples may also be taken to look for abnormal right heart tissue.
Molecular genetic analysis of DNA is beginning to reveal some recognisable changes or mutations in some genes. To date three genes responsible for ARVC have been identified, and it is expected that more will be implicated. In the future genetic tests may be able to be used to provide a mechanism for including or excluding family members from ongoing screening tests for ARVC, (that is a diagnosis can be made before symptoms occur). Although ARVC can be inherited, doctors remain unsure why some individuals who carry genes for the condition, do not manifest any symptoms for it throughout their lives, whilst others are affected by the condition at a young age.
Diagnosis of ARVC is based predominantly on having at least two of the major accepted diagnostic criteria for the condition or at least one major and 2 minor criteria. Diagnosis of ARVC is a skilled process and therefore it may take several different diagnostic tests and skilled interpretation of these before the diagnosis of ARVC is made.
Treatment
for ARVC
There is currently no known cure for ARVC. Treatments are currently directed at prevention of sudden death and collapse that result from rapid ventricular arrhythmia’s, which render the heart incapable of maintaining circulation of blood to the brain and body.
Treatments for ARVC include medications to help stabilise the heart rhythm and prevent the heart from beating too vigorously, your doctor will advise you which medications are best for you. Implantable defibrillators may be placed into some people who are felt to be at high risk, these devices detect rapid erratic heart beats and give a ‘shock’ which allows the heart’s own pacemaker to take over and control the heart rhythm again. Devices such as the implantable defibrillator are usually used in conjunction with medical therapy.
Other treatments may include ablation of the sites in the heart which are causing the rapid heart rhythm, and sometimes this needs to be done by cryoablation (freezing of the tissue in small areas of heart muscle to stop dangerous heart rhythms) which is performed during open heart surgery.
Your doctor will advise you which treatments are recommended in your case.
Your doctor may also ask you to refrain from intense physical activity, heavy manual labour and competitive sports.
Additional
information
If you would like more information about ARVC, the following websites may be useful.
Participation
in research into ARVC
If you would like more information, prior to deciding whether you would like to participate in the Cardiac inherited disease registry, please feel free to contact us (full contact details are available at the top of this form).
If you would like more information about your rights as a participant in a research study please feel free to contact these organisations.
Health
Advocate Trust: Phone (09) 623 5799 Auckland or toll-free 0800 555 050 Northland
to Franklin.
Mata
Forbes RGON; Co-ordinator/Advisor, Maori Health Services, Auckland Healthcare
Services Ltd, Auckland Hospital Grafton; Phone Mobile 021 348 432, or Work (09)
307 4949 Ext. 7972.
This
registry has the approval of the Auckland Ethics Committee: AKX/02/00/107.