What is third degree heart block?
A person with third degree heart block has a delay in the electrical impulse that travels through the heart, resulting in an abnormal heartbeat. The heart contains four chambers: two small atria make up the top of the heart, and two large ventricles make up the bottom of the heart. An electrical impulse stimulates the muscle fibers in the heart to contract. The impulse spreads through the heart in a very organized manner, so that the atria contract first, followed by the ventricles. In third degree heart block, an organized heartbeat is lost: the ventricles beat independently of the atria. Common causes of third degree heart block include a heart attack or a drug side effect.

What are the symptoms of third degree heart block?
Symptoms of third degree heart block may include chest pain, palpitations, shortness of breath, excessive sweating, fatigue, faintness, or fainting. The symptoms of third degree heart block are worse during exertion.

How does the doctor treat third degree heart block?
Treatment for third degree heart block includes stopping medication that may cause heart block. Additional treatment for a third degree heart block may include intravenous fluids, cardiac monitoring, blood pressure monitoring, medication, and pacemaker therapy.