Familial Arrhythmia Syndromes


The heart muscle is responsible for circulating blood throughout the body. When the heart does not operate as it is supposed to and develops an irregular or abnormal rhythm, the condition is known as an abnormal heart rhythm, or arrhythmia.

Arrhythmia is any variation from the heartbeat's normal rhythm. The heart rate at rest is usually between 60 and 100 beats per minute. Much lower rates may be normal in young adults, particularly those who are physically fit. Variations in heart rate are normal. The heart rate responds not only to exercise and inactivity but also to such factors as pain and anger. When the heart rate is too fast or too slow, or when the electrical impulses travel in abnormal pathways, the heartbeat is considered abnormal. Such rhythms may be regular or irregular.

Arrhythmia can be broken down into two main causes:

  • Primary electrical disease: arrhythmias in the absence of structural heart disease
  • Secondary arrhythmia syndromes: arrhythmias in the presence of structural heart disease

When the condition is genetic and passed down through families, it is known as a familial arrhythmia. Types of familial arrhythmia include:


Symptoms of familial arrhythmia syndromes can vary depending on the type and cause of the arrhythmia. General arrhythmia symptoms that patients may experience are:

  • Palpitations — the feeling of a rapid or fluttering heartbeat
  • Pounding in the chest
  • Dizziness
  • Shortness of breath
  • Weakness or fatigue

How a patient describes his or her arrhythmia symptoms often helps the physician diagnose the type of arrhythmia and determine how serious it is. The most important considerations are whether:

  • Heartbeats are fast or slow, regular or irregular, or short or long
  • Person feels dizzy, light-headed, faint, or even loses consciousness
  • Person is experiencing chest pain, shortness of breath or other unusual sensations along with the palpitations
  • Palpitations happen when the patient is at rest or only during strenuous or unusual activity
  • Palpitations start and stop suddenly or gradually

Causes and Risk Factors

Familial arrhythmias are diagnosed in patients of all ages, genders and ethnicities. Patients with a family history of arrhythmia may be at an increased risk of developing the condition. The condition can be caused by many different situations, including:

If a patient has a family history of arrhythmia, hypertension, heart disease, cardiomyopathy, valve disorders or heart attack, they should talk to their physician about evaluating their risk of developing an arrhythmia.


Diagnosis of an arrhythmia will generally begin with the physician taking a medical history and performing a physical exam. During the physical exam, the physician will listen to the patient’s heart and lungs to detect any abnormal heart sounds. Patients are also asked for a detailed description of their symptoms.

After the physical exam, the physician may order tests to examine the heart muscle, the blood flow through the heart, and any potential leaking within the heart valves. An echocardiogram is a noninvasive procedure using a machine called a transducer that bounces sound waves off the heart and back into the transducer. These echoes are then translated into visual images. If the echocardiogram is inconclusive, imaging tests such as a cardiac MRI or chest X-ray may be used to see if the heart is enlarged.

An electrocardiogram is also noninvasive and may be used to examine the electrical activity of the heart. In some cases, it may be important to monitor the electrical activity over the course of an entire day. To do this, a portable device known as a Holter monitor is used.

If a long-term, life-threatening arrhythmia is suspected, electrophysiology studies may also be used to look at the electrical system of the heart.


Treatment of arrhythmias will vary from one patient to another and will depend on the type, severity and cause of the condition. In some cases, when the abnormal heart rhythm is caused by an underlying condition — such as high blood pressure — treatment may focus on addressing that underlying condition. Treatment options may include lifestyle changes, medication, and sometimes surgery.

Lifestyle changes can often help manage arrhythmia symptoms. Maintaining a healthy weight and diet — such as eating foods low in sodium, sugar, saturated and trans fats, and cholesterol — are important for managing the condition. Engaging in physician-approved exercise may also be prescribed. Cedars-Sinai's Nutrition Counseling Services and New Leaf Personal Exercise Program may be part of the interdisciplinary healthcare team, in order to provide guidance and assistance to patients seeking lifestyle changes.

Medications such as beta blockers or calcium channel blockers may be used to slow the heartbeat and relax the heart muscle so that it can work more efficiently. Anticoagulants may also be prescribed to thin the blood and reduce the chance of a blood clot.

In some cases, surgery may be needed to implant a defibrillator or pacemaker. Catheter ablation is another treatment option. During this procedure, abnormal electrical pathways in the heart are eliminated using heat.

The knowledgeable and highly trained staff at the Cedars-Sinai Heart Institute will work with each patient to determine the best treatment option.

© 2000-2022 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
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