Tests and diagnosisBy Mayo Clinic staff
An electrocardiogram (ECG) is the test used to diagnose bundle branch block. This noninvasive test is an electrical recording of your heart's activity. In this test, a technician places probes on the skin of your chest that will show the patterns of electrical impulses through your heart as wave patterns. Abnormalities in the waves may indicate the presence of bundle branch block. These electrical patterns can also point to whether the block is affecting the right or the left bundle branch.
It's also possible your doctor will discover you have a bundle branch block incidentally — meaning the condition could be found while you're having an ECG to diagnose another heart condition.
Once you have been diagnosed with bundle branch block, your doctor may order other tests, such an echocardiogram. An echocardiogram uses sound waves to produce images of the heart. An echocardiogram allows the doctor to see the complicated movement of the heart in motion. An echocardiogram provides detailed images of the heart's structure and shows the thickness of your heart muscle and whether your heart valves are moving normally. Congenital heart defects, such as a hole between the upper chambers of the heart (atrial septal defect), can be diagnosed with an echocardiogram.
- 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.