Heart block

The yellow parts of this drawing show the heart's electrical pathways. Normally, electricity travels down these pathways to make the heart beat. With heart block, there is a block in one of these pathways, so electricity cannot travel normally through the heart

Heart block is a type of heart disease. The human heart uses electrical signals to make the heart beat. Electricity travels down pathways in the heart to make each part of the heart beat at the right time.

When a person has a heart block, there is a “block” in one of these electrical pathways. This blocks electricity from travelling normally through the heart. This makes the heart beat more slowly.

In the most serious cases, the heart’s electrical pathways are blocked so badly that electricity cannot travel through the heart. This means the heart’s electrical signals cannot control how the heart beats, or cannot make the heart beat at all.