How is AV block treated?

Photo of a woman measuring a man’s blood pressure

If AV block (also called heart block) causes your heart to beat so slowly that you have symptoms, you will usually need a . This device makes your heart beat fast enough again.

In AV block (atrioventricular block), the electrical signals in the heart don’t travel normally from the upper chambers (atria) to the lower chambers (ventricles). If it's mild, the signals are only delayed and there are often no symptoms. In more severe cases, only some (or even no) signals reach the lower chambers. Then the heart beats very slowly or may even stop beating for some time. This typically causes symptoms like fainting, dizziness, shortness of breath, weakness and .

The treatment options for AV block depend on what's causing it and how severe it is. Eliminating the root cause can sometimes make AV block go away completely – for example, if it was being caused by medication or an acute .

Does AV block always have to be treated?

No. Some people have mild AV block and don’t even notice it. For example, athletes and teenagers sometimes have it while resting or sleeping. But this change in signal transmission is not considered to be a medical problem. It goes away as soon as they become active again and their heart rate increases. So no treatment is needed.

What is a pacemaker?

A pacemaker is a device that sends out electrical signals. If your heart stops sending its own signals regularly or fast enough, the becomes active and makes the heart muscle squeeze regularly – so the sets the pace of the heartbeat. The device is implanted in a minor surgical procedure – usually under local anesthesia. The surgeon slides it under the skin or under the large chest muscle below the collarbone. From there, it sends electrical signals to the heart along thin wires (leads).

Illustration: Pacemaker with leads on the right side of the heart

In some people, a can be implanted directly into the heart without leads.

For urgent treatment in emergencies, external pacemakers are normally used. They are larger and heavier than implanted pacemakers, and make it harder to move freely. So they are only a temporary solution. If an external is used, the electrode leads are often fed through a vein into the heart. The electrical signals given off in the heart don’t cause any discomfort. Sometimes the electrodes of external pacemakers are placed on the skin instead. Then the electrical signals are unpleasant, so this treatment is done under general anesthesia.

When is a pacemaker needed?

Pacemakers are usually recommended if AV block causes symptoms over a long period of time. They are also recommended if other heart problems cause the heart to beat very slowly and lead to related symptoms – like if the sinus node isn't working properly.

Sometimes a is considered even if you don't have any noticeable symptoms. For example, in severe (third-degree) AV block or in a type of second-degree AV block known as “Mobitz type 2.”

If you're deciding whether or not to get a , you can use our decision aid to help you weigh the pros and cons.

Pacemakers are generally used in the treatment of heart rhythm disorders that lead to an abnormally slow heartbeat (bradycardia). Some people with heart failure get a too. Their not only sets the pace of the heartbeat: It also makes sure that the different areas of the heart muscle work together effectively – for example, by making both of the lower heart chambers (ventricles) squeeze at the same time. This treatment is also known as cardiac resynchronization therapy (CRT).

What are the risks of treatment with a pacemaker?

Pacemakers rarely cause complications. Like any kind of surgery, the procedure to implant the device can lead to infections, wound-healing problems or bleeding (if blood vessels, the lungs, or the wall of the heart are injured).

Later, there is a slight risk of the electrode leads moving out of place or being damaged over time. Other rare complications include malfunctions and " syndrome" (with a pounding heart, dizziness and shortness of breath). Pacemaker syndrome can develop if the upper and lower heart chambers aren't in sync with one another. But this can be avoided with modern pacemakers.

Can medication help too?

Medication for AV block is only considered in an emergency. Then the doctor may inject medication like atropine or adrenaline (epinephrine) to quickly increase the heart rate. Certain medications can be used in emergencies too because they can also increase the heart rate. This emergency medication can make sure the heart doesn't stop pumping blood around the body. It is a temporary solution until a permanent can be implanted or the cause of the AV block is successfully treated.

The potential side effects of the medication include blood pressure fluctuations, an abnormal heartbeat, skin problems and allergic reactions.

American College of Cardiology (ACC), American Heart Association Task Force on Clinical Practice Guidelines (AHA), Heart Rhythm Society (HRS). ACC/AHA/HRS Guideline on the Evaluation and Management of Patients with Bradycardia and Cardiac Conduction Delay. 2018.

Deutsche Gesellschaft für Kardiologie (DGK). Pocket-Leitlinie: Schrittmacher- und kardiale Resynchronisationstherapie. 2021.

Glikson M, Nielsen JC, Kronborg MB et al. 2021 ESC Guidelines on cardiac pacing and cardiac resynchronization therapy. Europace 2022; 24(1): 71-164.

Kasper DL, Fauci AS, Hauser SL et al. Harrison's Principles of Internal Medicine. New York: McGraw-Hill; 2015.

Saab L, Suarthana E, Almeida N et al. Use of biventricular pacing in atrioventricular heart block. Technology Assessment Unit of the McGill University Health Centre (MUHC). 2016.

IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Created on November 7, 2023

Next planned update: 2026


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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