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Can't find an answer to your ARVD question? Please contact the ARVD coordinator at Johns Hopkins. We want to hear from you!
What is ARVD?
ARVD stands for Arrhythmogenic Right Ventricular Dysplasia. Arrhythmogenic means
causing an arrhythmia. The right ventricle is the chamber of the heart that
is affected and dysplasia means there is an abnormality of the structure. ARVD
is a specific type of cardiomyopathy (a disorder of the cardiac muscle).
Simply put, ARVD is a genetic, progressive heart condition in which the
muscle of the right ventricle is replaced by fat and fibrosis, which causes
abnormal heart rhythms. ARVD is estimated to affect one in 5,000 people.
The disease can affect both men and women. Although it is a relatively
uncommon cause of sudden cardiac death, it accounts for up to one fifth
of sudden cardiac death in people under 35 years of age. [Return to Top]
What is an arrhythmia?
An arrhythmia is an abnormal heart rhythm. At rest, the heart normally beats
with a regular rhythm at 60 to 100 beats per minute. Tachycardia is when the
heart beats too fast and bradycardia is when the heart beats too slow. The arrhythmia
can be described further by indicating what part of the heart is starting the
abnormal rhythm. If the arrhythmia is coming from the ventricle, it is called
a ventricular arrhythmia. There are several types of ventricular arrhythmias.
PVCs are premature ventricular contractions, which are the most common type
of ventricular arrhythmias. Many people have isolated PVCs and have healthy
hearts. PVCs can alternate with the normal rhythm in a regular pattern. If the
ratio is one normal beat to one PVC, the rhythm is called bigeminy. If the ratio
is two normal beats to one PVC, it is called trigeminy. Ventricular tachycardia
(VT) is a run of more than 3 consecutive PVCs. An arrhythmia can be short lasting,
called unsustained, or long lasting, called sustained. A sustained rate of over
120 beats per minute will usually require medical treatment. Very fast ventricular
arrhythmias can be life-threatening.
[Return to Top]
What
are symptoms of ARVD?
The symptoms of ARVD are usually a result of an arrhythmia. Many people
do not know they have an arrhythmia. There are many different symptoms
of an arrhythmia and healthy people without ARVD can have these symptoms.
When you feel your heart speed up or slow down or feel it pounding, it
is called palpitation. Palpitations are a normal response to fright or
exertion but can, in other circumstances, be abnormal. If the change in
rhythm makes it difficult for the heart to pump blood, other symptoms
can occur such as lightheadedness and fainting (also called syncope).
Arrhythmias can also impair the flow of blood to the heart muscle and
cause chest pain, which is also called angina. An arrhythmia can also
cause sudden death if the heart cannot pump enough blood to its own muscle
and to the lungs and body. Fortunately, sudden death is not a common complication,
but the risk must be considered when deciding on the treatment.
Sometimes people with ARVD develop symptoms of heart failure. Heart failure
means that the heart muscle is not pumping blood through the body effectively.
Symptoms include swelling of the legs, feet, and abdomen; feelings of
shortness of breath while lying down and while exercising, and feelings
of extreme fatigue.
In addition to these common symptoms of arrhythmias
and heart failure other symptoms individuals with ARVD
have reported include nausea, dizziness, heart fluttering, heart racing,
etc.
[Return to Top]
How
is ARVD diagnosed?
It is often difficult to diagnose ARVD and there is
no single test which can alone definitively make or exclude
the diagnosis. However, the results of a careful medical
history, physical exam by a nurse or doctor and a number of cardiac tests
can be used to make a diagnosis. The cardiac tests are an electrocardiogram
(ECG), a signal averaged ECG (SAECG), an exercise stress test, an echocardiogram,
cardiac MRI and a 24-hour Holter monitor. It is extremely
important that the cardiac MRI be performed at in institution familiar
in doing cardiac MRI's to evaluate for ARVD, as these studies are difficult
to interpret accurately. In addition to these standard tests, an electrophysiology
study (EP study), right ventriculogram, and biopsy may
be recommended to completely evaluate for ARVD. Other tests that provide
information about the heart structure and function include a CT scan and
MUGA scan. An autopsy can show ARVD if the heart is carefully examined.
There
is a set of criteria that are based on the finding
of certain major and minor findings on cardiac tests and
on the family history. A list of the criteria can be
found elsewhere on this website.
[Return
to Top]
How is ARVD treated? Treatment focuses on controlling the arrhythmias and in managing any
signs or symptoms of heart failure. Most people with ARVD take medications
called antiarrhythmic agents which can help lessen the frequency and severity
of arrhythmias. A common treatment for ARVD is the implantation of an
implantable cardioverter defibrillator (ICD). This device monitors the
heart's rhythm and delivers an electrical shock to the heart to return
it to the normal rhythm if necessary. Sometimes an electrophysiology study
(EP study) can determine which areas of the heart are causing the abnormal
rhythm, and these areas can be eliminated (ablated). However, because
ARVD is a progressive disease, the arrhythmias are not permanently cured
by this procedure.
Individuals with signs or symptoms of heart failure
are treated with medications. These medications include
ACE inhibitors which make it easier for the heart to pump
blood and diuretics which reduce symptoms of heart failure. Although there
is not yet a proven benefit to ACE inhibitors in ARVD patients without
heart failure symptoms, many doctors are now treating patients prophylactically
to help delay the progression of ARVD.
The most
extreme treatment of ARVD is to have a heart transplant.
This is rarely necessary. It is used only when the heart is very weak
or when arrhythmias cannot be controlled no other treatment is successful. [Return to Top]
Once ARVD is diagnosed, how is it managed?
Once ARVD has been diagnosed, the majority of patients undergo implantation
of an implantable cardioverter defibrillator (ICD). In general, this will
require that you see your doctor for an ICD check-up every 3-6 months.
In addition, the status and progression of your ARVD should be monitored
with yearly echocardiograms and electrocardiograms. Some institutions
may also be able to perform a cardiac MRI depending on the type of ICD
that you have. Your doctor may also request additional testing, such as
a CT scan or stress test every couple of years. A close working relationship
with your doctor is necessary to monitor the effectiveness of your medications
in controlling your arrhythmias.
[Return
to Top]
What is the
prognosis of ARVD?
In our experience, the majority of patients who stop exercising
early on in the course of their ARVD do quite well. Once the arrhythmias
are controlled with medication and an ICD is in place, very few individuals
die from ARVD. However, now that the ICD is the recommended
treatment offering protection from sudden cardiac death, individuals
with ARVD are living longer. This means there may be more individuals
with heart failure requiring a heart transplant in the future.
[Return
to Top]
What causes
ARVD?
There is a lot of evidence that ARVD is a genetic, heritable
condition where an affected person has a chance of passing on a specific
gene change to his or her children. There is also some evidence that
ARVD could result from an infection of the heart muscle. One or both
theories could be correct. For instance, an infection in someone with
a certain genetic make-up could cause ARVD.
In general, someone who inherits a gene change or mutation for ARVD has
inherited a genetic predisposition to developing ARVD. A single gene change
is usually not sufficient for the development of ARVD. We think that for
most individuals, additional factors such as other genes, athletic lifestyle,
exposure to certain viruses, etc. are needed for an individual to actually
develop signs and symptoms of ARVD. This is an area of very active research
and we have a lot to learn about all the factors that can cause ARVD.
There are rarer forms of ARVD that have been shown to
be passed on in a family in an autosomal recessive pattern. This means
that both parents of someone affected with ARVD carry a gene change for
ARVD but they do not have ARVD themselves. However, each of their children
has a 25% chance of inheriting both copies of the gene change which results
in the development of ARVD. This type of pattern is seen in Naxos disease,
a variant of ARVD predominantly seen in Greece. [Return
to Top]
How
is ARVD inherited?
To help explain the inheritance of ARVD,
let us back up and explain some concepts of biology. Our bodies are
made up of cells and in each cell in the nucleus, is DNA. The DNA
is a string of messages that we call genes. Genes are like sentences
in that certain letters are put together to make a code that are the
instructions for telling our bodies how to look and function. If a
letter or letters from a sentence or missing or added in the wrong
place, the genetic sentence will not make sense and can result in
genetic disorders like ARVD. These gene changes can be passed on from
one generation to the next. In general you have two copies
of every gene, one from your mother and one from you father.
ARVD can be inherited in 2 different ways: autosomal
dominant inheritance with reduced penetrance and autosomal recessive inheritance.
In autosomal dominant inheritance, a person with a gene change predisposing
them to ARVD has a 50% chance of passing on that same predisposition to
their child. We know that not everyone who inherits a gene change associated
with ARVD will develop ARVD. This is called “reduced penetrance”. Among
people in a family who get ARVD there is variation in the
severity of the disease and the age that ARVD starts. We are working hard
to figure out what genetic and other factors predict which people with
a genetic change go on to develop ARVD.
In autosomal recessive inheritance, an individual has to have two copies
of a gene associated with ARVD to get the disease. A person has a 25%
chance of inheriting both copies of the gene changes responsible for ARVD
(one from dad and one from mom). Each parent “carries” a gene change but
does not have ARVD. This type of pattern is seen in Naxos disease, a variant
of ARVD predominantly seen in Greece . Autosomal dominant appears to be
the most common pattern of inheritance. [Return to Top]
What
genes are associated with ARVD?
Known ARVD variants
with inheritance pattern (AD = autosomal dominant,
AR = autosomal recessive), chromosome location, and name of gene
if known .
| Genetics of Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy |
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| Gene (Symbol) |
Locus |
Inheritance |
Notes |
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11%-43% |
| Plakophilin-2 (PKP2)* |
12q11 |
AD/AR |
1 family with recessive mutation has been reported without hair or skin abnormalities |
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| Desmoglein-2 (DSG2)* |
18q12 |
AD/AR |
10%-12% |
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6%-16% |
| Desmoplakin (DSP)* |
6p24 |
AD |
ARVD/C or arrhythmogenic left ventricular cardiomyopathy |
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| Desmocollin-2 (DSC2)* |
18q12 |
AD |
1%-5% |
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| Transforming growth factor-beta3 (TGF B3) |
14q24.3 |
AD |
2 families worldwide |
| Plakoglobin (JUP) |
17q21 |
AD |
ARVD/C without cutaneous abnormalities (German ancestry - one family) |
| Plakoglobin (JUP) |
17q21 |
AR |
ARVD/C, palmoplantar keratoderma, woolly hair (Greek Ancestry) - "Naxos" |
| Desmoplakin (DSP) |
6p24 |
AR |
woolly hair, palmoplantar keratoderma, left-sided dilated cardiomyopathy - "Carvajal" |
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catecholaminergic polymorphic ventricular tachycardia |
| Cardiac Ryanodine Receptor (RYR2) |
1q42 |
AD |
Atypical form of ARVD |
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fully penetrant, sex-influenced form of ARVD/C |
| Transmembrane protein 43 (TMEM43) |
3p25 |
AD |
Newfoundland ancestry |
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Seven genes (plakoglobin, plakophilin-2, desmoplakin, ryanodine receptor-2, transforming growth factor beta-3, desmoglein-2, and desmocollin-2) and their exact gene changes have been identified and published to date.
[Return
to Top]
Is there a genetic test for ARVD?
Clinical genetic testing for plakophilin-2, desmoplakin, desmoglein-2, and desmocollin-2 is now available in the United States. Plakophilin-2 testing is available through the DNA Diagnostic Laboratory at Johns Hopkins. Additional information can be found at http://www.hopkinsmedicine.org/dnadiagnostic/. Clinical testing for plakophilin-2, desmoplakin, desmoglein-2, and desmocollin-2 is available through Harvard Laboratory for Molecular Medicine. Additional information can be found at http://www.hpcgg.org/. The Harvard lab does not bill insurance companies. In addition, The Hospital of Sick Kids in Toronto, Canada is also offering clinical testing for plakophilin-2, desmoplakin, desmoglein-2, and desmocollin-2. Additional information can be found at http://www.sickkids.ca/molecular/. If you are interested in finding out more about genetic testing for ARVD, please contact one of our genetic counselors at 410-502-7161 for more information. We are happy to work with you, your physicians, and your insurance company in understanding the risks, benefits, and limitations of genetic testing in your specific situation. There are many research laboratories that offer testing on a research basis, however, many of these labs are unable to provide results or require clinical confirmation of a research result. There are some institutions outside of the United States (Canada, France, Netherlands, and Germany) that offer clinical testing for plakophilin-2, ryanodine receptor, desmoplakin, desmoglein-2, and desmocollin-2. We strongly recommend that you meet with a genetic counselor (www.nsgc.org) beforehand to discuss the benefits, risks, and limitations of genetic testing. Interpretation of genetic test results for ARVD can be quite complex.
[Return
to Top]
If
someone in my family has ARVD, should everyone be screened?
There is a lot of evidence that ARVD is genetic and as a result,
there are some recommendations for other family members. After the diagnosis
is made in one person, all of his or her first-degree relatives should
be screened. First-degree relatives are siblings, parents and children
of someone diagnosed with ARVD. If another person in the family is then
found to be affected, then all of their first-degree relatives of that
person need to be screened. This is called stepwise screening. To further
explain this, take an example of Joe who is diagnosed with ARVD. Joe's
first-degree relatives (his siblings, parents and children) are all screened
in step 1. Joe's father, Ed is also affected. Now in step 2, Ed's first-degree
relatives need to be screened. This process is repeated until all at-risk
relatives have been screened. If a more distant relative has symptoms
of an arrhythmia, we would recommend that person be screened as well.
While ARVD is most commonly diagnosed in adults
in their 20s and 30s, both children and older people
have been diagnosed. Children who have an affected parent should see
a pediatric cardiologist to discuss appropriate cardiac testing. Similarly,
older relatives, though they may not appear to have any symptoms, should
still be tested because they may have mild symptoms of ARVD.
[Return to Top]
If
I have ARVD, what tests do my first degree relatives need to have
done?
Unfortunately, no single cardiac test can diagnose ARVD. First degree
relatives need to have all 6 of the tests listed below
in order to determine if they are affected or unaffected. These tests are
necessary in order to determine if someone meets the diagnostic criteria.
The tests are:
Standard 12 lead ECG
Signal averaged ECG with 40mHz filter
Holter monitor for 24 hours
Echocardiogram
Exercise stress test
Cardiac MRI
It may be necessary to have more cardiac testing
if some of the above tests are abnormal. The additional
testing may be needed to clarify indeterminate results of the previous
tests.
[Return to Top]
How
often should family members be screened for ARVD?
First-degree
family members of an individual diagnosed with ARVD should be evaluated
every 2-5 years with an ECG, signal averaged ECG, exercise stress test,
24-hour Holter monitor, echocardiogram, and cardiac MRI. The recommended
time period for repeat screening will vary among family members depending
on results of previous testing, reported symptoms, and family history.
[Return to Top]
Can
an infant or young child be diagnosed with ARVD?
Yes, but
it is rare. Young children rarely have symptoms and are rarely affected.
Several of these tests are not routinely performed on children or
may require sedation in order to be performed. Thus, cardiac testing
young children should be discussed with your cardiologist
and pediatrician who may refer your child to a pediatric cardiologist.
Testing recommendations will vary depending on the child 's symptoms
and family history. Teenagers can have symptoms and should have an
evaluation in order to establish a baseline. At this time no formal
guidelines have been established or published. Click here for screening
recommendations from Johns Hopkins.
[Return to Top]
What
should I know about participating in genetic research
studies?
When
you agree to participate in any study, you should take
the time to read the consent form carefully. Ash questions if you
don 't understand something. Many genetic research studies do not
release results, mainly because the laboratory that the genetic research
is being performed in is not a CLIA certified lab. CLIA stands for
Clinical Laboratory Improvement Amendment . The role of the CLIA program
is to ensure quality laboratory testing. Research labs are not required
to adhere to any special regulations. In the majority of cases when
you donate a blood sample for research, a unique number, not your
name, is written on the sample tube. There is always the chance for
a sample mix-up, mislabeling, or inactive reagents resulting in an
inaccurate results.
[Return to Top]
What
should I know about genetic research being performed at Johns Hopkins?
If
you meet the diagnostic criteria for ARVD, you may have provided a
blood sample as part of the Clinical and Genetic Investigations of
ARVD study at Johns Hopkins. We have been screening blood
samples from individuals meeting the diagnostic criteria for gene
changes thought to be associated with ARVD. Although the Johns Hopkins
Institutional Review Board does not permit us to release research
results, we will notify you if a result becomes available and will
assist you in obtaining clinical confirmation testing through a CLIA
certified laboratory. There is a fee associated with this confirmation
testing. This confirmation testing is important as samples may become
mixed up or mislabeled since they are labeled with a research number
only and not your name. Genetic results should not be used to determine
management until they are confirmed in a CLIA certified laboratory.
[Return to Top] If I have ARVD, should I get an implantable cardioverter defibrillator (ICD)?
Not every patient with ARVD needs to have an ICD. Each person's
medical case is different, so it is best to discuss this with your doctor.
ICDs are not a cure although they have been shown to effectively treat episodes
of ventricular tachycardia and ventricular fibrillation in ARVD patients.
However, there have not been any studies directly comparing how ARVD patients
with and without ICD's do.. There are some studies that show heart attack
patients with non-sustained ventricular tachycardia do better with ICD than
with medication. However, these study patients have different heart abnormalities
than ARVD patients.
[Return to Top]
If I have ARVD, can I exercise?
The exact relationship between ARVD and exercise is not clear. For
many patients with ARVD, exercise can be an immediate cause of arrhythmia.
There seems to be an increased incidence of ARVD in young very athletic
people, particularly men. There are also numerous reports of sudden cardiac
death from ARVD that occur during physical exertion. In addition, the gene
changes recently found in many people with ARVD are in genes that hold heart
muscle cells together. We think that exercise, therefore, puts an extra
strain on these already weak heart muscle connections. Therefore, it's possible
that an athletic lifestyle for someone who has inherited a genetic predisposition
for ARVD may be sufficient for that individual to develop ARVD. Therefore,
we recommend that patients with ARVD should not do vigorous exercise. It
is best to discuss with your doctor about what types of exercise are appropriate
for you.
[Return to Top]
Is
pregnancy safe for someone with ARVD?
Although there is very limited information on pregnancy in individuals
with ARVD, W w omen with ARVD have had uncomplicated pregnancies,
even when on medications or with an ICD. There are some medications that
can harm the baby as it develops, and your doctor may recommend that you
switch medications on a temporary basis. at least temporarily. Pregnancy
does put extra strain on the heart, and thus, if you are planning a pregnancy,
or become pregnant you should see your cardiologist and obstetrician as
early as possible. You should discuss with your doctor about medication
options during delivery, delivery options, and monitoring of your heart
during labor.
[Return to Top]
Do
ARVD patients have to avoid any medications or substances
that exacerbate VT?
Patients who are prone to arrhythmias, caused by ARVD
or other conditions, are generally advised to avoid
stimulants of all kinds. Stimulants include nicotine and caffeine as well
as pharmacological stimulants such as Sudafed (pseudoephedrine), which is
commonly used in cold and flu medications. Patients prone to arrhythmias
are advised to limit their intake of alcohol, a depressant, which is also
proven to cause arrhythmias.
If you take medications to suppress your arrhythmias,
such as Atenolol or another beta blocker, and your arrhythmia
is under control, then moderate exposure to stimulants
should not be problematic. This means go ahead and take the cold medicine
for a week or two, or have an occasional bar of chocolate, just don't
take either in huge amounts for a long time! Arrhythmias can be provoked
for many different reasons when you are ill, including fever, electrolyte
imbalance and decreased absorption of the anti-arrhythmia medication.
People who are predisposed to arrhythmias may have more arrhythmias when
they are ill, but it is difficult, if not impossible, to be sure of the
exact cause. Thus, our advice is to use cold medications only as needed,
but read the labels and ask your pharmacist about the stimulant content,
so you know what you are taking.
Patients with ARVD can get arrhythmias
without an increase in stimulants or exposure to alcohol.
These arrhythmias can happen at any time, because the heart
has an abnormal ability to conduct electrical impulses. Although it is
human nature to try to find a cause and effect relationship, there will
not be an identifiable cause for all arrhythmias. Understanding this is
true and that one cannot control for all the variables that cause or effect
an arrhythmia, may help patients in coping with the unpredictable nature
of their symptoms. [Return to Top]
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