Familial Arrhythmias and Arrhythmic Cardiomyopathies

At UT Southwestern Medical Center, our specialists offer state-of-the-art cardiac care based on the latest research. As one of the nation’s leading heart programs, our team provides advanced diagnosis, genetic testing, and treatment for patients with inherited heart rhythm disorders.

Expert Care for Familial Arrhythmia and Arrhythmic Cardiomyopathies

An arrhythmia is an abnormal heart rhythm, or heartbeat, which can be either too fast or too slow. The heart rate normally varies in response to factors such as physical activity, stress, or pain. But when there are problems with the heart’s electrical system, which regulates heart rate, the abnormal heartbeat is considered an arrhythmia.

With a multidisciplinary team of specialists in heart rhythm disorders, heart disease, and genetic conditions, UT Southwestern provides comprehensive services to diagnose and treat arrhythmic conditions. We coordinate patient care across medical specialties for genetic testing and counseling and minimally invasive interventional cardiology procedures.

Types of Familial Arrhythmias and Arrhythmic Cardiomyopathies

Familial arrhythmias result from genetic mutations and are passed down through families. These include:

• Atrial fibrillation
• Arrhythmogenic right ventricular dysplasia (ARVD)
• Amyloid cardiomyopathy
• Brugada syndrome
• Hypertrophic cardiomyopathy
• Idiopathic ventricular fibrillation
• Lamin AC cardiomyopathy
• Long QT syndrome
• Muscular dystrophy
• Noncompaction cardiomyopathy
• Phospholamban cardiomyopathy
• Sarcoid cardiomyopathy
• Short QT syndrome
• Wolff-Parkinson-White syndrome

Causes of Familial Arrhythmias and Arrhythmic Cardiomyopathies

Although familial arrhythmias result from inherited gene mutations, having the abnormal gene alone does not necessarily mean that a person will develop an arrhythmia. The two patterns of inheritance are:

• Autosomal dominant: One parent has a copy of the abnormal gene, which means that the child has a 50 percent chance of inheriting the gene.
  
• Autosomal recessive: The child inherits a copy of the abnormal gene from both parents. 

Familial arrhythmias can affect patients of any age, gender, or ethnicity. People who have the gene mutation for familial arrhythmias can develop the condition from causes such as:

• Cardiomyopathy, diseases of the heart muscle that cause it to enlarge or thicken, such as amyloid, sarcoid, and hypertrophic cardiomyopathy
• Cardiomyopathies that cause the heart to dilate, such as ARVD, lamic AC, and phosholamban cardiomyopathies
• Primary electrical disease, such as Brugada syndrome, idiopathic ventricular fibrillation, and Long QT syndrome

Symptoms of Familial Arrhythmias and Arrhythmic Cardiomyopathies

Depending on the type and cause of the arrhythmia, symptoms can vary, and some people might not experience symptoms at all. Common symptoms include:

• Dizziness or lightheadedness
• Heart palpitations (rapid or fluttering heartbeat)
• Pain or pounding in the chest
• Shortness of breath
• Syncope (fainting)
• Weakness or fatigue

Certain factors can help doctors pinpoint the type of arrhythmia for a diagnosis. These factors include:

• Heartbeat pattern, such as fast or slow, or short or long
  
• Palpitations that happen at rest, or during light or strenuous activity
  
• Palpitations that start or stop suddenly or gradually
  

Diagnosis of Familial Arrhythmias and Arrhythmic Cardiomyopathies

If left untreated, some arrhythmias can become life threatening. It’s important for people who have any of the symptoms to see their doctor as soon as possible.

At UT Southwestern, our experienced heart specialists conduct a thorough evaluation to confirm a diagnosis. Our diagnostic process includes a physical exam and discussion of the patient’s personal and family medical history. During the exam, our doctors ask patients to describe any symptoms they are experiencing. 

To determine the specific type of familial arrhythmia, our doctors generally use one or more tests, such as:

• Electrocardiogram (EKG): A noninvasive test that records the heart’s electrical activity to check for abnormal heart rhythms
  
• Long-term ambulatory monitor: A portable device that records the heart’s electrical activity over an extended period of time
  
• Chest X-ray: Imaging that doctors use to examine organs and other structures inside the chest, which can show signs of heart failure or causes of other, unrelated conditions
  
• Stress test: A way to evaluate patients during exercise, which is particularly important for those with exertional symptoms
  
• Echocardiogram: An ultrasound that uses sound waves to produce images of the heart to assess heart function, size and shape of the heart, blood flow to the heart, and previous injury to heart muscle
  
• Electrophysiology study: Minimally invasive procedure in which a catheter (long, thin, flexible tube) is inserted through a tiny incision into an artery to assess the heart’s electrical activity
  
• Ablation: Pinpoints the abnormal tissue causing the arrhythmia and cauterizes it to cure the patient of the arrhythmia
  
• Cardiac magnetic resonance imaging (MRI): Imaging that uses magnets and a computer to show moving and still images of the heart and its blood vessels to assess blood flow
  
• Genetic testing: Specialized blood tests that look for genetic abnormalities to confirm a diagnosis and help determine whether family members should be evaluated for familial arrhythmia
  

Treatment Options for Familial Arrhythmias and Arrhythmic Cardiomyopathies

Treatment options vary depending on the type of familial arrhythmia, its severity, and its underlying cause. The goals are to:

• Relieve symptoms
  
• Reduce the risk of life-threatening complications such as blood clots, heart failure, or sudden cardiac arrest or death 

Healthy lifestyle habits can help manage symptoms of familial arrhythmias and arrhythmic cardiomyopathies. UT Southwestern offers a Preventive Cardiology program that provides personalized support to help patients make healthy lifestyle changes, such as:

• Not smoking and avoiding secondhand smoke
  
• Eating a healthy diet
  
• Getting physical activity
  
• Maintaining a healthy weight

Additional options for treating familial arrhythmias and arrhythmic cardiomyopathies include:

• Medications to relax the heart muscle, slow the heartbeat, and/or thin the blood to reduce the risk of blood clots
  
• Interventional cardiology procedures using cardiac catheterization to perform ablation, which is the use of heat energy to treat specific parts of the heart to correct abnormal electrical activity
  
• Surgery to implant electrical devices such as pacemakers or implantable cardioverter-defibrillators to regulate heartbeat
  
• Cardiac rehabilitation to either prevent heart disease complications or support recovery after a heart procedure or heart attack