Heart block is a condition where the heart beats much more slowly than normal. It is caused by a delay, or disruption, of the electrical signals that control the heartbeat.

A healthy heart beats between 60 and 80 times a minute.  A heartbeat is when the muscles of the heart contract and push blood around the body.  These muscle contractions are controlled by electrical signals that travel between the heart’s upper chambers (the atria) and lower chambers (the ventricles).

If these electrical impulses are delayed or stopped), then your heart may not beat regularly.  If the electrical signals are stopped completely (complete heart block), then the heart will only beat around 40 times a minute.

Heart block reduces your heart’s efficiency in pushing blood around the body.  This means that your muscles and brain may not be getting enough oxygen for them to work properly.

Types of heart block

There are three different types of heart block:

• First degree heart block (the least serious) refers to a delay in conduction of electricity from the atrium to the ventricle and often does not need treatment.
• Second degree heart block is where some of the electrical signals do not reach your heart, causing ‘drooped’ beats.  It can cause dizziness and sometimes a pacemaker is needed.
• Third degree or complete heart block (the most serious) is when the electrical signals do not travel between the upper and lower chambers of your heart.  It is most common in adults with heart disease, and can have serious complications, such as heart attack, if it is not treated with a pacemaker.