Arrhythmogenic cardiomyopathy

Diagnosis

To diagnose arrhythmogenic cardiomyopathy (ACM), your healthcare professional examines you. You usually are asked questions about your symptoms and health history.

Before diagnosing ACM, your healthcare team does tests to rule out other conditions that could be causing your symptoms. One condition is myocarditis, which is swelling and irritation of the heart muscle.

The tests look at your heart muscle and how well your heart pumps. They also check for changes in your heartbeat. To diagnose ACM, at least one test must show scarring in the heart muscle or a change in how a lower heart chamber moves or pumps. But there is no single test to diagnose the condition in every person.

To diagnose ACM and its type, your healthcare team considers your symptoms, the heart chamber or chambers affected, your family history, and all test results.

Blood tests

A blood test can't tell for sure whether you have arrhythmogenic cardiomyopathy (ACM). But blood tests can help your healthcare team look for signs of heart failure. Heart failure can be a complication of ACM.

Blood tests may include:

• N-terminal pro-B-type natriuretic peptide (NT-proBNP). The heart releases this substance into the bloodstream when it's under stress, such as during heart failure. If NT-proBNP testing is not available, you may have a regular BNP test.
• Troponin. This is a protein found in heart muscle. Higher levels of the protein may mean there is heart damage.

You may have other blood tests, depending on your symptoms.

Echocardiogram

An echocardiogram is one of the main tests for arrhythmogenic cardiomyopathy (ACM). It uses sound waves to make moving pictures of the heart. Another name for this test is an ultrasound of the heart.

An echocardiogram shows how blood flows through the heart chambers and heart valves. A measurement taken during the test shows how much blood your lower left chamber pushes out with each heartbeat. This measurement is called the ejection fraction. The result is given as a percentage. A lower ejection fraction means the heart is not pumping as strongly as it should.

To help diagnose ACM, your healthcare professional looks at the echocardiogram for changes in the size and movement of the lower heart chambers and how well the heart pumps.

Other tests

Other tests can help your healthcare team look for changes in your heart and heartbeat. They may be used to rule out other conditions that can cause similar symptoms.

• Electrocardiogram (ECG). This quick and painless test shows how the heart is beating. Sticky patches with sensors on them, called electrodes, go on the chest and sometimes the arms and legs. Wires connect the electrodes to a computer, which prints or shows the test results. Your healthcare professional can look for patterns in the test results that may be due to arrhythmogenic cardiomyopathy. However, an ECG cannot diagnose arrhythmogenic cardiomyopathy by itself.
• Holter monitor. This is a small, wearable ECG device. It records the heartbeat for a day or more while you do your daily activities. This test can find irregular heartbeats that aren't seen on a regular ECG.
• Chest X-ray. A chest X-ray shows the lungs and heart. It can show whether the heart is larger than usual or if there is fluid buildup in the lungs. These things can happen with heart failure.
• Cardiac MRI. This test uses magnetic fields and radio waves to make images of the heart. It can give your healthcare team more information about the heart's structure and how well it pumps. It can show the heart chambers and changes in the heart muscle. A cardiac MRI is especially helpful when ACM affects the left lower heart chamber. During the test, you may get a solution called contrast through a vein. The contrast helps show any areas of scarring in the heart muscle.

Genetic testing

Arrhythmogenic cardiomyopathy (ACM) is linked to several gene changes that can be passed down through families. If your healthcare professional thinks you have ACM, genetic testing may be recommended.

Finding a gene change related to ACM can help confirm the diagnosis. If you have ACM, your healthcare team also may recommend genetic testing for your first-degree relatives. These relatives are your parents, siblings and children.

Ask your healthcare professional if genetic testing is right for you or your family. A genetic counselor can explain what a test result may mean for you and your family. Some people with a related gene change may not show signs of ACM.

Treatment

If you have arrhythmogenic cardiomyopathy (ACM), a team of healthcare professionals works together to treat your condition and support your care. Your care team depends on your specific needs but may include:

• Doctors trained in heart conditions, called cardiologists.
• Heart failure specialists.
• A primary healthcare professional.
• A doctor trained in heartbeat conditions, called an electrophysiologist.
• A genetic counselor.

The goals of arrhythmogenic cardiomyopathy treatment are to:

• Prevent or control dangerous heartbeats.
• Ease symptoms.
• Lower the risk of complications.

Your healthcare professional thinks about your test results and history of heartbeat changes when choosing your treatment plan. Your family history and gene test results also may help guide your care. Treatment may include medicines, a heart device, a heart procedure or a heart transplant. Some people need more than one type of treatment.

Medicines

Many types of medicines are used to treat arrhythmogenic cardiomyopathy (ACM). Medicines can help:

• Slow the heartbeat.
• Help the heart pump better.
• Lower blood pressure.
• Remove extra fluid and sodium from the body.

Medicines may include:

• Diuretics. These medicines help your body get rid of extra fluid.
• Beta blockers. These medicines slow the heartbeat. They can help the heart pump better. In ACM, beta blockers may help prevent irregular heartbeats triggered by exercise or stress. A medicine called flecainide may be given with a beta blocker if other treatment has not worked.
• Medicines to control dangerous heartbeat changes. These medicines are called antiarrhythmics. Examples include sotalol (Betapace, Sorine) and amiodarone (Pacerone, Nexterone).
• Medicines that help the heart pump better. These medicines may be used if ACM causes heart failure. They include angiotensin-converting enzyme (ACE) inhibitors, angiotensin 2 receptor blockers (ARBs), hydralazine-isosorbide dinitrate, and others.

Heart devices

Some people with arrhythmogenic cardiomyopathy (ACM) may need a heart device. A heart device may help stop dangerous heartbeat changes or help the heart pump better.

Heart devices include:

• Implantable cardioverter-defibrillator (ICD). This device is placed in the chest. It monitors the heartbeat. It gives an electric shock if needed to stop a dangerous heartbeat. An ICD may be recommended for people with arrhythmogenic cardiomyopathy who are at high risk of sudden cardiac arrest.
• Pacemaker. A pacemaker prevents the heart from beating too slowly. Some people with ACM may need a pacemaker if the heartbeat becomes too slow.
• Cardiac resynchronization therapy (CRT). This is a treatment for some people who have heart failure. It uses a device to help the lower heart chambers squeeze at the same time. This helps the heart pump blood better.
• Ventricular assist device (VAD). A VAD helps pump blood from the lower chambers of the heart to the rest of the body. It's a treatment for a weakened heart or heart failure. A VAD may help the heart work while a person waits for a heart transplant.

Cardiac ablation

Some people with arrhythmogenic cardiomyopathy may have dangerous changes in their heartbeat. They may need a treatment called cardiac ablation.

During ablation, a doctor places one or more thin, soft tubes called catheters into blood vessels that lead to the heart. Sensors at the catheter tips use heat or cold energy to create tiny scars in the heart. The scars block signals that cause irregular heartbeats.

Ablation may be used when an irregular heartbeat called ventricular tachycardia (VT) keeps coming back and medicines don't work or cause side effects. The treatment can reduce episodes of VT. It does not cure arrhythmogenic cardiomyopathy.

Heart transplant

A heart transplant is surgery to replace a damaged heart with a healthy heart from a person who is no longer living.

Not everyone with arrhythmogenic cardiomyopathy needs a heart transplant. It may be an option if arrhythmogenic cardiomyopathy causes severe heart failure and other treatments don't help enough. Some people may have a ventricular assist device (VAD) to help the heart pump while waiting for a transplant.

A heart transplant may improve quality of life.

Prognosis

Arrhythmogenic cardiomyopathy is a lifelong condition. The outlook, also called prognosis, is different for each person. It can depend on the type of ACM you have.

Some people with ACM do well. They may have few or no symptoms for years. Their condition may stay stable. Others have irregular heartbeats that keep coming back, heart failure or both.

In general, people with ACM that affects the right lower heart chamber or both lower chambers tend to have more dangerous heartbeat changes. Heart failure is more common when the condition affects the left lower heart chamber or both lower chambers.

Your prognosis may change over time. Your healthcare team looks at your symptoms, heart and heartbeat changes, and how well treatment works for you to understand your prognosis.

Clinical trials

Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.

Lifestyle and home remedies

You can take an active part in your care. Follow the arrhythmogenic cardiomyopathy (ACM) treatment plan from your care team. Your care team may ask you to:

• Go to all health checkups. Your healthcare team may do regular tests to check your heart and heartbeat.
• Ask about exercise. If you have ACM linked to a gene called PKP2, very hard exercise and competitive endurance sports may raise your risk of dangerous heartbeats. They also may make your condition get worse. Your healthcare team may tell you not to do some exercise or sports. Light exercise may be an option. Ask your healthcare team what types of sports and exercises are safe for you.
• Know how much salt is OK to eat. If ACM causes heart failure, too much salt can make your body hold extra fluid. Ask your healthcare team what amount of salt is right for you.
• Check your weight every day. Quick weight gain can be a sign of heart failure.

Coping and support

Arrhythmogenic cardiomyopathy (ACM) can cause heartbeat changes. Because of this, you might need to make changes to your exercise and activities. These changes may be hard. Talk with your healthcare team if you feel worried, sad or stressed about living with ACM. Your care team can help you find support for the emotional side of living with ACM. Support may include counseling or other mental healthcare.

Some people find it helpful to talk with others who are going through similar experiences. You might consider joining a support group. Ask your healthcare team if there are ACM support groups in your area.

Also, genetic counseling can help families understand how ACM is passed down through families. It also can help families understand what genetic test results may mean for them.

Preparing for your appointment

If you think you may have arrhythmogenic cardiomyopathy or are worried about your risk, see your healthcare professional. You may be sent to a heart doctor, called a cardiologist.

Here's information to help you get ready for your appointment.

What you can do

When you make the appointment, ask if there's anything you need to do in advance. For example, you may be told not to eat or drink for a short while before some blood tests.

Make a list of:

• Your symptoms. Include any that may not seem related to your heart. Note when your symptoms began.
• Important personal information. Include any family history of cardiomyopathy, heart disease, stroke, high blood pressure or diabetes. Also note any major stresses or recent life changes.
• All medicines, vitamins or other supplements you take. Include those you bought without a prescription. Include the doses.
• Questions to ask your healthcare team.

Take a family member or friend along if you can. This person can help you remember the information you're given.

For arrhythmogenic cardiomyopathy, some basic questions to ask your healthcare professional include:

• What's the most likely cause of my symptoms?
• What are other possible causes?
• What tests do I need?
• What treatment options are available, and which do you recommend for me?
• How often do I need heart tests?
• Should I or my family members have genetic testing?
• I have other health conditions. How can I best manage these conditions together?
• Is there any information that I can take home with me? What websites do you recommend?

What to expect from your doctor

Your healthcare team is likely to ask you questions such as:

• Do you have symptoms all the time, or do they come and go?
• On a scale of 1 to 10, with 10 being the worst, how bad are your symptoms?
• What, if anything, makes your symptoms better?
• What, if anything, makes your symptoms worse?
• What kinds of exercise or sports do you do, and how often?
• Have you ever fainted during or just after exercise?
• Have you ever had a racing or pounding heartbeat during exercise?
• Has anyone in your family had cardiomyopathy, sudden cardiac arrest or sudden death that could not be explained?