Arrhythmogenic Cardiomyopathy (ACM)

What Is Arrhythmogenic Cardiomyopathy (ACM)?

Arrhythmogenic cardiomyopathy (ACM) is a condition in the myocardium, the heart's muscular wall. A defect in proteins that connect heart muscle cells (myocytes) causes the cells to die. They are replaced by scar tissue and fatty cells. A subset of ACM that affects the right ventricle disproportionately is called arrhythmic right ventricular cardiomyopathy (ARVC) or arrhythmogenic right ventricular dysplasia (ARVD).

Over time, the heart muscle becomes weaker and has trouble pumping enough oxygen-rich blood to the rest of the body. Over time, arrhythmogenic cardiomyopathy can lead to:

• Arrhythmia, abnormal heart rate and rhythm
• Heart failure
• Sudden cardiac death

Arrhythmogenic Cardiomyopathy Symptoms

ACM may not produce any signs in the early stages. The symptoms often appear in adulthood and worsen over time. They include:

• Arrhythmia, such as atrial fibrillation, premature ventricular contraction, ventricular tachycardia and ventricular fibrillation
• Fatigue
• Fluttering or pounding feeling in the chest (palpitations)
• Lightheadedness
• Fainting
• Shortness of breath because of fluid build-up in the lungs
• Swelling in the feet, ankles, legs or belly

Diagnosis of Arrhythmogenic Cardiomyopathy and AVRC

Arrhythmogenic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy can be difficult to diagnose because the symptoms mimic those of other conditions. It's often misdiagnosed as dilated cardiomyopathy. The experts at Penn Medicine have decades of experience diagnosing ACM, ARVC, and other cardiomyopathies. Your evaluation at Penn might include:

• Physical exam and medical history: We ask you detailed questions about your medical history and family medical history. Then we do a thorough exam to look for features of ACM.
• Blood tests: Lab tests can measure iron in the blood or find markers of autoimmune disease, thyroid disease, infection and other conditions.
• Cardiac catheterization: This test measures pressure in and around your heart.
• Coronary angiography: This test takes images of the coronary arteries (blood vessels) to look for disease.
• Echocardiogram (echo): This test uses sound waves to take pictures of the heart's structure.
• Electrocardiogram (ECG): This test records the electrical impulses in the heart and can detect any abnormal patterns in rate or rhythm.
• Electrophysiology study: An electrophysiologist inserts a thin tube through a blood vessel and into the heart to measure electrical activity. This test can help assess the risk of sudden death.
• Genetic testing and counseling: ACM can involve changes (variants) in at least 13 genes, with PKP2the most common. Anyone having genetic testing should also have genetic counseling. A trained counselor helps you understand the process and what it might mean for you and your family.
• Holter monitor: This wearable device monitors the heart's electrical activity as you go about your daily activities.
• Implantable loop recorder: This small device is implanted under the skin and records the heart's electrical activity to detect arrhythmia. 
• Other imaging tests: We have many options to take pictures inside your heart, including CT, MRI, radionuclide tests and more.
• Stress test: Also called an exercise test, this measures heart function while you walk or run on a treadmill.

Arrhythmogenic Cardiomyopathy and ARVC Treatment at Penn

Consistent monitoring can help identify problems from arrhythmogenic cardiomyopathy before they interfere with your health. Treatment varies, depending on your condition and symptoms.

Medications used for treatment of ACM include:

• Angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers, which reduce the heart's workload
• Anti-arrhythmia medications to control the rate and rhythm of the heartbeat
• Beta blockers, which lessen the rate and force of the heart's contractions
• Blood thinners to prevent clots and stroke
• Diuretics (water pills) to reduce fluid build-up

Some people with ACM or ARVC need procedures or surgery, such as:

• Cardioversion, a procedure that delivers an electric shock to the heart to restore a normal heart rate and rhythm.
• Catheter ablation (or radiofrequency ablation), a procedure that uses energy to destroy diseased heart tissue and abnormal electrical signals causing arrhythmias
• Implantable devices to regulate the heart rate and rhythm, such as pacemakers or implantable cardioverter defibrillators (ICDs)
• Heart transplantation with a deceased donor's heart for advanced cases

The Penn network has specialists with extensive training and experience in cardiomyopathy and all its possible treatments. They work together to find the right treatment for you and coordinate your care. Your team may include experts in:

• Arrhythmia
• Cardiovascular surgery
• Coronary artery disease
• Familial cardiomyopathy
• Heart failure
• Heart transplantation
• Heart valve repair and replacement
• Inherited cardiac disease
• Palliative care

Penn Programs & Services for Arrhythmogenic Cardiomyopathy (ACM)