Heart block is a condition where the heart beats irregularly or more slowly than normal. Sometimes, the heart even stops for up to 20 seconds. It's caused by a delay or disruption of electrical signals that control the heartbeat.
A healthy heart beats 60-80 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 (partial heart block), then your heart may not beat regularly. If the electrical signals are stopped completely (complete heart block), then the heart will beat around 40 times a minute.
Heart block reduces your heart's efficiency in pushing blood around the body. This means your muscles and brain may not get enough oxygen to work properly.
Types of heart block
There are three different types of heart block:
- First degree heart block: this is the least serious and usually refers to skipped beats or some other kind of disruption. Treatment is not always needed.
- Second degree heart block: some of the electrical signals do not reach your heart, causing "drooped" beats. It can cause dizziness. Sometimes a pacemaker is needed.
- Third degree or complete heart block: this is the most serious type and it occurs 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.
Bundle branch block/AV bundle
Heart block is also known as bundle branch block or AV bundle. This is because the electrical impulses that control the heart's muscle contraction pass through what is known as the "bundle of HIS".
This is the part of your heart where muscle fibres are divided into a right bundle and a left bundle. Together they control the heart's contraction and, in a normal healthy heart, both contract together.
Bundle branch block is a common condition. In most cases, there is no obvious cause. If a signal block occurs in the right side of your heart (right bundle branch block) it is not considered a serious concern. However, if the block is in the left side (left bundle branch block) it is usually associated with an increased risk of developing a heart problem, such as coronary artery disease.
