If you have a right bundle branch block and you're otherwise healthy, you might not need a full evaluation. If you have a left bundle branch block, you will need a full evaluation.

Tests that can be used to diagnose a bundle branch block or its causes include:

  • Electrocardiogram. This records the electrical impulses in your heart through wires attached to the skin on your chest and other places on your body. Abnormalities might indicate a bundle branch block, as well as which side is being affected.
  • Echocardiogram. This test uses sound waves to provide detailed images of the heart's structure and shows the thickness of your heart muscle and whether your heart valves are moving normally. It can pinpoint a condition that caused the bundle branch block.


Most people with bundle branch block are symptom-free and don't need treatment.

However, if you have a heart condition causing bundle branch block, treatment might involve medications to reduce high blood pressure or lessen the effects of heart failure.

Additionally, depending on your symptoms and whether you have other heart problems, your doctor might recommend:

  • A pacemaker. If you have bundle branch block and a history of fainting, your doctor might recommend a pacemaker. This compact device is implanted under the skin of your upper chest (internal pacemaker) with two wires that connect to the right side of your heart. The pacemaker provides electrical impulses when needed to keep your heart beating regularly.
  • Cardiac resynchronization therapy. Also known as biventricular pacing, this procedure is similar to having a pacemaker implanted. However, with this procedure, there's a third wire that's connected to the left side of the heart so the device can keep both sides in proper rhythm.

    This therapy, which is meant to improve the coordination of both lower chambers of the heart so that they contract at the same time, is used in people with low pumping function and a bundle branch block.

More Information

Clinical trials

Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this disease.

Preparing for your appointment

You're likely to start by seeing your primary care doctor. You might be referred to a doctor trained in heart disorders (cardiologist).

Here's some information to help you get ready for your appointment.

What you can do

Be aware of pre-appointment restrictions. When you make the appointment, ask if there's anything you need to do in advance, such as restrict your caffeine intake before having heart function tests.

Make a list of:

  • Your symptoms, including any that seem unrelated to the reason for which you scheduled the appointment, when they began and how often they occur
  • Key personal information, including major stresses or recent life changes
  • All medications, vitamins and supplements you take, including the doses
  • Questions to ask your doctor

Ask a family member or friend to come with you, if possible, to help you remember the information you receive.

For bundle branch block, questions to ask your doctor include:

  • What are the most likely causes of my symptoms?
  • What tests do I need?
  • What treatments are available, and which do you recommend?
  • Will the bundle branch block return after treatment?
  • What side effects might I expect from treatment?
  • I have other health conditions. How can I best manage them together?
  • Do you have brochures or other printed material I can have? What websites do you recommend?

What to expect from your doctor

Your doctor is likely to ask you questions, including:

  • Does anything seem to improve your symptoms?
  • What, if anything, appears to worsen your symptoms?
  • Has a doctor ever told you that you have a bundle branch block?
May 15, 2018
  1. Conduction disorders. American Heart Association. http://www.heart.org/HEARTORG/Conditions/Arrhythmia/AboutArrhythmia/Conduction-Disorders_UCM_302046_Article.jsp. Accessed Feb. 11, 2018.
  2. Sauer WH. Left bundle branch block. https://www.uptodate.com/contents/search. Accessed Feb. 11, 2018.
  3. Sauer WH. Right bundle branch block. https://www.uptodate.com/contents/search. Accessed Feb. 11, 2018.
  4. Bundle branch block and fascicular block. Merck Manual Professional Version. https://www.merckmanuals.com/professional/cardiovascular-disorders/arrhythmias-and-conduction-disorders/bundle-branch-block-and-fascicular-block. Accessed Feb. 11, 2018.
  5. Cardiac resynchronization therapy. American Heart Association. http://www.heart.org/HEARTORG/Conditions/HeartFailure/Cardiac-Resynchronization-Therapy_UCM_452920_Article.jsp. Accessed Feb. 11, 2018.
  6. Lopez-Jimenez F (expert opinion). Mayo Clinic, Rochester, Minn. Accessed March 4, 2018.