Everything You Need to Know About Inherited Cardiomyopathies

Dilated cardiomyopathy is the most common form of cardiomyopathy. Up to one-third of people with the disease inherit it from their parents.

This form of cardiomyopathy typically occurs in adults under the age of 50. It affects the lower and upper chambers of the heart.

As the disease progresses, it can cause the heart muscle to dilate, stretch, and become thinner. Thinner or thinning heart muscle can cause heart weakness or heart failure.

Some people have few to no symptoms, but others may experience them. Symptoms of dilated cardiomyopathy, particularly heart failure, can include:

• shortness of breath
• fatigue
• swelling in the ankles, abdomen, legs, feet, and veins in the neck

Doctors may recommend lifestyle changes, like eating a balanced diet and getting exercise. They may also prescribe medications, such as drugs that lower blood pressure or slow your heart rate, to treat dilated cardiomyopathy.

In more serious cases, surgical and minimally invasive procedures can treat dilated cardiomyopathy. These include open-heart surgery, pacemakers, or heart transplants.

Hypertrophic cardiomyopathy (HCM) is most often caused by abnormal genes in the heart muscle. In addition to genetic testing, a physical or diagnostic test, such as an echocardiogram, can help check risk levels or diagnose HCM.

HCM comes in obstructive and nonobstructive forms. The obstructive form of the disease is the most common type. It includes thickening heart walls that block or reduce blood flow from the heart to the body.

Nonobstructive HCM can cause a thickening of the heart muscle but doesn’t block blood flow out of the heart.

Signs and symptoms include:

• chest pain, shortness of breath, or both (especially with exercise)
• fatigue
• arrhythmias
• dizziness
• lightheadedness
• fainting
• swelling in the ankles, feet, legs, or abdomen

Doctors often recommend lifestyle changes to slow the progression of HCM. Medication, surgery, or other therapies can also be considered.

Restrictive cardiomyopathy is a rare form of cardiomyopathy. It tends to affect older adults.

This form can cause the heart’s ventricles to become rigid from abnormal tissue, such as proteins, replacing normal heart muscle. As a result, the heart’s ventricles can’t relax as they should and fill with blood, causing the atria to become enlarged from high pressure.

Over time, restrictive cardiomyopathy can reduce blood flow in the heart. This can lead to complications like heart failure or arrhythmias.

Symptoms can include:

• shortness of breath
• fatigue
• inability to exercise
• swelling of the legs and feet
• weight gain
• nausea, bloating, and poor appetite

Managing heart failure is one of the main focuses of restrictive cardiomyopathy treatment. Doctors often prescribe diuretics to reduce excess fluid and sodium in the body. They may also recommend lifestyle changes, such as eating a balanced diet and getting exercise.

Another rare form of inherited cardiomyopathy is arrhythmogenic right ventricular dysplasia (ARVD).

It occurs when the muscle tissue in the right ventricle dies and is replaced with fatty tissue. This can then disrupt the heart’s electrical signals and cause arrhythmias.

Symptoms of ARVD include:

• heart palpitations
• fainting after physical activity

The disease typically affects teens or young adults. It can cause sudden cardiac arrest in young athletes.

Sometimes, an abnormal electrocardiogram is detected, prompting additional testing. A cardiac MRI is typically used to diagnose ARVD.

Researchers suggest teens and young adults get tested for ARVD every 2 to 3 years if there’s a family history, especially since the disease onset occurs at a young age.

Condition management can include a combination of:

• lifestyle changes
• medication
• catheter ablation
• implantable cardioverter-defibrillator (ICD)
• heart transplant

ARVD treatment often focuses on preventing disease progression.

A third rare form of cardiomyopathy is transthyretin amyloid cardiomyopathy (ATTR-CM).

This underdiagnosed and potentially fatal condition causes deposits of amyloid protein fibrils in the walls of the left heart ventricle. This can cause heart walls to become stiff.

Stiffening heart walls prevent the left ventricle from relaxing and filling with blood, therefore making it unable to pump blood out of the heart and into the body.

Genetic testing can help determine whether you’re predisposed to ATTR-CM. The American Heart Association says hereditary forms are often found in localized parts of Portugal, Sweden, and Japan.

ATTR-CM also occurs in African American populations in the United States, affecting approximately 1 in 25 African Americans.

Symptoms of ATTR-CM include those associated with heart failure, such as:

• shortness of breath
• swelling in the feet, ankles, and legs
• heart palpitations
• bloating in the abdomen
• confusion or trouble thinking
• increased heart rate

Treatment of ATTR-CM focuses on managing heart failure and slowing or stopping the formation and depositing of fibrils.

Medication is often considered. In more severe cases, a heart transplant may be needed. Some people may also need a liver transplant since abnormal transthyretin protein is produced by the liver as well.

Many forms of cardiomyopathy are inherited. Being aware of the signs and symptoms can help you get early diagnosis and treatment.

If heart problems run in your family, consider regular follow-ups with your physician to check for any changes or abnormalities.

Genetic testing can also help determine your risk level, although all culprit genes have not yet been fully identified.