The estimated prevalence of
arrhythmogenic right ventricular cardiomyopathy (ARVC) - also known as
arrhythmogenic right ventricular dysplasia (ARVD) - in the general population
ranges from 1 in 1,000 to 1 in 5,000, depending on the definition of the
condition.
It was first recognised in the late
1970s. It is thought that even more information regarding ARVC will be available
in the coming years, to improve understanding of the condition.
The disease affects men and women
equally and has been recognised in people of diverse ethnic backgrounds. It
tends to develop in early adulthood but can occasionally affect children.
ARVC is caused by a defect in the
‘glue’ that holds the muscle cells of the heart together, working as a unit.
CRY Consultant
Cardiologist Professor
Sanjay Sharma describes
arrhythmogenic right
ventricular cardiomyopathy
(ARVC)
Professor Sanjay Sharma
discusses the genetics of ARVC
When stretched, the ‘glue’ breaks down, the muscle cells separate and
some die. The body then tries to repair this, resulting in replacement
of the normal heart muscle cells by scar and fat tissue.
This may only involve small areas of the right ventricle but may
progress with time and may become more widespread and even involve the
left ventricle. Some forms only affect the left ventricle.
The precise cause of ARVC is not known. The condition is normally familial
and is passed on in the genes from one generation to the next.
The pattern of
inheritance is autosomal dominant such that the child of an affected parent will
have 50% chance of inheriting the abnormal gene.
Often people have no symptoms at all, although they may feel
palpitations (feeling the pulse racing or the heart pounding erratically or
rapidly) which is the most common symptom. This may also be associated with
light-headedness or a blackout. Unlike most cardiomyopathies, shortness of
breath and chest pains are unusual symptoms and people may only experience these
very late on in the condition, if at all.
The diagnosis can be extremely
difficult and usually requires several tests undertaken by a specialist, as
there is no single ‘diagnostic’ test. In the first instance, a detailed history
and examination is required. Most of the tests are painless and non-invasive and
include an ECG, signal
average ECG and an ultrasound scan (ECHO).
The ECG can often pick up an
abnormality, but the signs on an ECHO can be very subtle in the early stages of
the condition. They are also often only seen in the right ventricle. Further
imaging with a
magnetic resonance imaging (MRI) scan may be required.
CRY Consultant Cardiologist
Professor Sanjay Sharma
discusses how ARVC is
diagnosed
In some specialist centres, further invasive tests
are performed to identify the electrical faults of the heart muscle associated
with ARVC (EP studies); and to take a small sample (biopsy) of the heart muscle
and examine it under the microscope. These investigations can still miss ARVC
and can be associated with some risk to the patient.
Advances in genetics (DNA) means that in some
hospitals, the condition may be diagnosed using a blood test. This test,
however, is not available in every hospital, may take up to several months and
it is not always positive in ARVC patients (it is possible to identify a
defective gene in 50% of patients with definite ARVC). It can be used to confirm
the diagnosis or identify blood relatives who may carry the condition.
CRY Consultant Cardiologist Professor
Sanjay Sharma
discusses treatments for ARVC
If tests prove positive for ARVC, a
specialist will advise on lifestyle modifications. It is most likely that this
will include advice to not participate in competitive, strenuous activities. The
majority of people with this condition are, however, asymptomatic for many years
unless heart rhythm problems (arrhythmia) develop. Treatment aims to prevent or
at least control these and tablets may be used to control the irregular heart
rhythms. These may include beta-blockers, amiodarone or sotalol.
In people for whom medicine is
unsuccessful in controlling rapid heart beats; or where blackouts, near
blackouts or even a cardiac arrest have occurred; an
implantable cardiac defibrillator (ICD) may be fitted.
In some cases, rhythm problem can be
very troublesome and the only way to control them is to destroy the parts of the
heart muscle causing them. This is known as
ablation and can be performed at the time of an EP study.
In a small number of individuals, the heart pump
weakens eventually and symptoms of heart failure (breathlessness and ankle
swelling) will require treatment - as described in
dilated
cardiomyopathy.
It will be necessary for you to have at least
annual check-ups, which usually will include a repeat of the initial
investigations. Since the disease runs in families, all immediate blood
relatives of people with ARVC should be screened with at least an ECG and
ECHO, as well as some of the additional tests described above.
It is recommended that when ARVC is identified in a family member, those
first degree blood relatives where the condition is NOT identified
should return for repeat testing every 2 - 5 years
until the age of 60 (although the exact frequency of repeat testing will
vary according to individual circumstances - e.g. number of family members
identified with ARVC, presence of symptoms, etc).
Call us at 01737 363 222 or email us at
cry@c-r-y.org.uk
CRY, Unit 7, Epsom Downs Metro
Centre, Waterfield, Tadworth, Surrey, KT20 5LR
A Company Limited by Guarantee.
Registered in England No. 3052965
Registered Office 35 - 37 Grosvenor
Gardens, London SW1 0BY. Registered Charity No. 1050845
All Copyright reserved by Cardiac Risk in the Young
