Symptoms
By Mayo Clinic staffIn most people, bundle branch block doesn't cause any symptoms. Sometimes, people with the condition don't even know they have a bundle branch block.
For those people who do have signs and symptoms, they may include:
- Fainting (syncope)
- Feeling as if you're going to faint (presyncope)
- Having a slow heart rate (bradycardia)
When to see a doctor
If you've fainted, see your doctor to rule out any serious, underlying causes.
If you have heart disease, or if your doctor has already diagnosed you as having bundle branch block, ask your doctor how often you should have follow-up visits. You might want to carry a medical alert card that identifies you as having bundle branch block in case you're seen in an emergency by a doctor who isn't familiar with your medical history.
- Conduction disorders. American Heart Association. http://www.heart.org/HEARTORG/Conditions/Arrhythmia/AboutArrhythmia/Conduction-Disorders_UCM_302046_Article.jsp#.T1QonfUzDTo. Accessed March 2, 2012.
- Bundle branch and fascicular block. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merck.com/mmpe/print/sec07/ch075/ch075i.html. Accessed March 2, 2012.
- Sauer WH. Right bundle branch block. http://www.uptodate.com/index. Accessed March 2, 2012.
- Moya A, et al. Diagnosis, management, and outcomes of patients with syncope and bundle branch block. European Heart Journal. 2011;32:1535.
- Sauer WH. Left bundle branch block. http://www.uptodate.com/index. Accessed March 2, 2012.
- Heart disease prevention: What you can do. U.S. Centers for Disease Control and Prevention. http://www.cdc.gov/heartdisease/what_you_can_do.htm. Accessed March 4, 2012.
- Grogan M (expert opinion). Mayo Clinic, Rochester, Minn. March 30, 2012.


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