Heart Block

Also known as: atrioventricular block, AV block, bradycardia, arrhythmia, abnormal heart rhythm

What is ​Heart Block?

Heart block is a problem that occurs with the heart’s electrical system. This system controls the speed and the rhythm of the hearts’ beats. Heart block occurs when an electrical signal is  slowed or is disrupted. For example a heart that beats too slowly, also known as bradycardia, is one potential cause of heart block. The block can either be a complete or partial and there are three types: first degree, second degree and third degree, with third degree being the most severe.

What causes heart block?

Some individuals are born with heart block as a congenital abnormality. Other times, it occurs later in life after a medical condition such as heart failure, rheumatic fever, heart disease or a heart attack.

What are the symptoms of heart block?

Signs and symptoms depend on the type of heart block.  When heart block is mild (first degree heart block)  the heart compensates, and the condition causes no symptoms. As it worsens, however, it can lead to fatigue, chest pain, shortness of breath, dizziness and even fainting.

What are heart block care options?

Mild cases of heart block require no treatment, only careful monitoring. When heart block begins causing symptoms, the typical treatment is surgery to implant a pacemaker in the heart to regulate the heartbeat.


Reviewed by: Jack Wolfsdorf, MD, FAAP

This page was last updated on: July 15, 2021 03:46 PM