A vagal maneuver is an action you take when you need to stop an abnormally fast heart rate. The word “vagal” refers to the vagus nerve. It’s a long nerve that runs from the brain down through the chest and into the abdomen. The vagus nerve has several functions, including slowing the heart rate.

There are several simple vagal maneuvers you can do to trigger the vagus nerve to slow down an accelerating heart rate. This is a condition known as tachycardia.

Your heart contains two natural pacemakers called the atrioventricular (AV) node and the sinoatrial (SA) node. The nodes are small pieces of muscle tissue that help control the flow of electrical energy through the heart.

Problems with the AV node are at the root of a condition called supraventricular tachycardia (SVT). SVT is a pattern of rapid heartbeats that start in the heart’s upper chambers, called the atria.

When the SA node becomes overly stimulated, you can experience sinus tachycardia. This is a condition similar to SVT. Vagal maneuvers can be helpful for sinus tachycardia, too.

Vagal maneuvers work by affecting the body’s autonomic nervous system. This part of your nervous system controls the functions you don’t have to think about, such as heart rate, digestion, respiratory rate, and others.

In the case of tachycardia, a vagal maneuver can cause the autonomic nervous system to slow electrical conduction through the AV node.

The goal of a vagal maneuver is to disrupt the flow of electrical energy through the heart. This allows your heart rate to return to normal. There are many different types of vagal maneuvers. Each one requires your autonomic nervous system to respond, essentially shocking it back into working properly.

Vagal maneuvers aren’t always effective. For people with serious heart rate problems, medications or procedures may be needed to correct the tachycardia.

You may have more success with one type of maneuver versus another. One common method is the Valsalva maneuver. It takes two forms.

In one form, simply pinch your nose closed and close your mouth. Then, try to exhale forcefully for about 20 seconds. This increases blood pressure inside the chest and forces more blood out of the chest and down the arms.

As your blood pressure increases, the arteries and veins tighten. Less blood can return to the heart through the narrowed veins. That means less blood can be pumped out through narrowed arteries. Your blood pressure will then start to fall.

A decrease in blood pressure means less blood can return to the heart until you relax and start to breathe normally. When you do, blood will start to refill the heart.

But because your arteries are still constricted, less blood can leave the heart, and your blood pressure will rise again. In response, your heart rate should start to slow down and return to normal.

The other form of a Valsalva maneuver produces a similar reaction in the body. It also starts by holding your breath. While holding your breath, bear down as though you were having a bowel movement. Try to hold this position for 20 seconds.

Other vagal maneuvers include coughing or dunking your face in a bowl of ice-cold water.

Vagal maneuvers should only be done if you have no other symptoms, such as lightheadedness, chest pain, or shortness of breath. These could be signs that you’re having a heart attack.

You could be having a stroke if a fast heart rate is accompanied by:

  • a sudden headache
  • numbness on one side of the body
  • loss of balance
  • slurred speech
  • vision problems

Actions that cause sudden spikes in blood pressure could cause more harm.

There are also risks associated with a type of vagal maneuver known as carotid sinus massage. It involves gentle massaging of the carotid artery. The carotid artery is located on the right and left sides of the neck. From there, it branches into two smaller blood vessels.

This move should only be done by a doctor who knows your medical history. If you have a blood clot in your carotid artery, massaging it could send it to the brain, causing a stroke.

A healthy heart rate rises when you exercise and then comes back to normal soon after you stop. If you have any type of tachycardia, physical activity could trigger an abnormally fast heart rate that won’t slow down when you stop moving. You may also feel your heart racing even if you’ve been sitting quietly.

If these types of episodes occur, wait for half an hour before you see a doctor. But only wait if you have no other symptoms or haven’t received a diagnosis of heart disease.

Sometimes an episode of tachycardia will end on its own. Sometimes a vagal maneuver will do the job.

If your heart rate is still high after 30 minutes, seek medical attention. If your heart rate rapidly increases and you have other symptoms — such as chest pain, dizziness, or shortness of breath — call your local emergency services.

Tachycardia episodes can happen once to a person, or they can be frequent. The only way to properly diagnose the condition is to have your heart rate recorded on an electrocardiogram (EKG). Your EKG can help reveal the nature of your heart rhythm problem.

Some cases of tachycardia don’t require any serious medical intervention. For some people with a heart rhythm disorder, the prescription drug adenosine (Adenocard) is helpful along with vagal maneuvers.

If you have SVT or sinus tachycardia, be sure to discuss with your doctor whether vagal maneuvers are safe for you. If they are, learn how to do them correctly and what to do if your heart rate doesn’t come back down afterward.