Bundle Branch Block

Overview

What are the bundle branches?

Normally, your heart beats in a nice, regular fashion. The heartbeat starts in the upper chambers of the heart in an area called the SA node. The impulse then moves to the AV node. The AV node is an area of tissue that carries the impulse through the Bundle of His and then splits into two wire-like branches (the bundle branches). The branches carry the impulse to the Purkinje fibers, which are located in the muscular walls of the ventricles, and cause them to contract.

What is a bundle branch block?

A bundle branch block means the electrical impulses that control the heartbeat cannot move properly throughout the heart. A block in the branches causes the impulses to travel slower than normal.

Types

Right bundle branch block (RBBB)

Right bundle branch block (RBBB) is very common, and the risk of developing the condition increases with age. Once your doctor sees RBBB on an EKG, the next step is to see if you have underlying heart disease.

If you do not have other heart disease, symptoms of heart disease, or other blocks in your electrical conduction system, no treatment is necessary.

If you have RBBB and another heart condition, such as heart attack or heart failure; dizziness or fainting; or other blocks in your electrical system, you will be treated for the heart disease. You may need a pacemaker if you have symptoms or another heart block.

Left bundle branch block (LBBB)

Left bundle branch block (LBBB) is less common than RBBB. As with RBBB, the risk of developing the condition increases with age. Once your doctor sees LBBB on an EKG, the next step is to see if you have underlying heart disease.

If you do not have other heart disease, symptoms of heart disease, or other blocks in your electrical conduction system, no treatment is necessary. If you have another heart condition, such as hypertension, coronary artery disease or heart attack, myocarditis or heart failure; dizziness, fainting or chest pain; or another block in your electrical system, you will be treated for the heart disease. You may need a pacemaker if you have another type of heart block or have symptoms of heart block.

How LBBB can affect other cardiovascular tests and conditions?

Stress testing and heart attack

Left bundle branch block can make it more difficult to diagnose left ventricular hypertrophy (LVH) and ischemia (decreased blood supply to the heart) during exercise stress testing and during a heart attack.

If you have LBBB, make sure your doctor knows about the condition before you have a stress test. You may need additional testing or a different kind of stress test (done with medicine, not exercise).

You should also carry a copy of your EKG with you.

If you think you are having a heart attack, be sure to tell your doctor or nurse that you have LBBB and give them the copy of the EKG. This will help them see changes in your heart.

If you have signs of LVH, your doctor will use an echocardiogram to diagnose the condition.

Diagnosis and Tests

Diagnosis of bundle branch block

A bundle branch block can be seen on an electrocardiogram (EKG).

Resources

Doctors vary in quality due to differences in training and experience; hospitals differ in the number of services available. The more complex your medical problem, the greater these differences in quality become and the more they matter.

Clearly, the doctor and hospital that you choose for complex, specialized medical care will have a direct impact on how well you do. To help you make this choice, please review our Miller Family Heart and Vascular Institute Outcomes.

Cleveland Clinic Heart and Vascular Institute Cardiologists and Surgeons

Choosing a doctor to treat your abnormal heart rhythm depends on where you are in your diagnosis and treatment. The following Heart and Vascular Institute Sections and Departments treat patients with Arrhythmias:

  • Section of Electrophysiology and Pacing: cardiology evaluation for medical management or electrophysiology procedures or devices - Call Cardiology Appointments at toll-free 800.223.2273, extension 4-6697 or request an appointment online.
  • Department of Thoracic and Cardiovascular Surgery: surgery evaluation for surgical treatment for atrial fibrillation, epicardial lead placement, and in some cases if necessary, lead and device implantation and removal. For more information, please contact us.
  • You may also use our MyConsult second opinion consultation using the Internet.

The Heart and Vascular Institute has specialized centers to treat certain populations of patients:

Learn more about experts who specialize in the diagnosis and treatment of arrhythmias

For younger patients with abnormal heart rhythms:

See: About Us to learn more about the Sydell and Arnold Miller Family Heart & Vascular Institute.

Contact

If you need more information about PVCs or to make an appointment with a Cleveland Clinic heart specialist, click here to contact us, chat online with a nurse or call the Miller Family Heart and Vascular Institute Resource & Information Nurse at 216.445.9288 or toll-free at 866.289.6911. We would be happy to help you.

Becoming a Patient

Treatment Options

Treatment Guides

Diagnostic Tests

Diagnostic tests are used to diagnose your abnormal heartbeat and the most effective treatment method.

Anatomy

Webchats

Our webchats and video chats give patients and visitors another opportunity to ask questions and interact with our physicians.

Videos

Interactive Tools

Why choose Cleveland Clinic for your care?

Our outcomes speak for themselves. Please review our facts and figures and if you have any questions don’t hesitate to ask.

*A new browser window will open with this link.

*The inclusion of links to other websites does not imply any endorsement of the material on those websites nor any association with their operators.

Last reviewed by a Cleveland Clinic medical professional on 05/24/2019.

References

  • Zipes, Douglas et al. Developed in Collaboration With the European Heart Rhythm Association and the Heart Rhythm Society. ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: A Report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (http://eurheartj.oxfordjournals.org/content/27/17/2099) , *J Am Coll Cardiol* 2006 48: e247-346.
  • * American Heart Association. "Premature Contractions." Retrieved on March 1, 2011, from AHA website: www.heart.org/HEARTORG/Conditions/Arrhythmia/AboutArrhythmia/Premature-Contractions_UCM_302043_Article.jsp (http://www.heart.org/HEARTORG/Conditions/Arrhythmia/AboutArrhythmia/Premature-Contractions/_UCM/_302043/_Article.jsp)
  • Heart Rhythm Society. "Heart Rhythm Disorders." Retrieved on March 1, 2011, from HRS website: www.hrsonline.org/PatientInfo/HeartRhythmDisorders/index.cfm (http://www.hrsonline.org/PatientInfo/HeartRhythmDisorders/index.cfm)
  • Heart Rhythm Society. "Skipped Heartbeats." Retrieved on March 1, 2011, from HRS website: www.hrsonline.org/patientinfo/symptomsdiagnosis/skipped/ (http://www.hrsonline.org/patientinfo/symptomsdiagnosis/skipped/) * The Merck Manuals Online Medical Library. "Ventricular Premature Beats (VPB)." Retrieved on March 1, 2011, from Merck Manuals website: www.merckmanuals.com/professional/sec07/ch075/ch075j.html (http://www.merckmanuals.com/professional/sec07/ch075/ch075j.html)

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy