Key Points

• Heart block is a problem that occurs with the heart's electrical system. This system controls the rate and rhythm of heartbeats.
• With each heartbeat, an electrical signal spreads across the heart from the upper to the lower chambers. As it travels, the signal causes the heart to contract and pump blood. The process repeats with each new heartbeat.
• Heart block occurs when the electrical signal is slowed or disrupted as it moves through the heart.
• You can be born with heart block or you can develop it. If you're born with it, it's called congenital heart block. If it develops after birth, it's called acquired heart block. Acquired heart block is more common.
• Doctors use a test called an EKG (electrocardiogram) to help diagnose heart block. This test detects and records the heart's electrical activity. An EKG records the strength and timing of electrical signals as they pass through each part of the heart. The data is recorded on a graph so your doctor can review it.
• The three types of heart block are: first degree, second degree, and third degree. First degree is the least severe and third degree is the most severe. This is true for both congenital and acquired heart block. Third-degree heart block may be fatal and requires prompt treatment.
• Heart block has a number of causes. Autoimmune diseases and congenital heart defects may cause congenital heart block. Diseases, surgery, medicines, and other conditions may cause acquired heart block.
• In some cases, acquired heart block may go away if the factor causing it is treated or resolved. For example, heart block that occurs after a heart attack or surgery may go away with recovery.
• Signs and symptoms depend on the type of heart block you have. First-degree heart block rarely causes symptoms. Symptoms of second- and third-degree heart block include fainting, feeling dizzy or lightheaded, fatigue (tiredness), shortness of breath, and chest pain.
• Heart block may be diagnosed as part of a routine doctor's visit or during an emergency situation (third-degree heart block is an emergency). Your doctor will diagnose heart block based on your family and medical histories, a physical exam, and results from tests.
• Treatment depends on the type of heart block you have. First-degree heart block usually needs no treatment. People who have third-degree heart block and some people who have second-degree heart block need pacemakers. A pacemaker is a small device that's placed under the skin of your chest or abdomen. This device uses electrical pulses to stimulate the heart to beat at a normal rate.
• If you have heart block or symptoms of heart block, it's important to talk to your doctor. He or she can tell you whether you need treatment and whether you should have ongoing medical care for your condition. If you have severe symptoms, you should call 9–1–1 or go to the hospital right away.