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By Mayo Clinic staffIn most people, bundle branch block doesn't cause any symptoms. For those people who do have signs and symptoms, they may include:
- Fainting (syncope)
- Dizziness
- Feeling as if you're going to faint (presyncope)
- A slow heart rate (brachycardia)
You may be born with the condition (congenital) and have bundle branch block for years without knowing it. This is particularly true with bundle branch block that occurs on the right side of your heart, which tends to be less serious than is left bundle branch block.