Patient education: Vagal maneuvers and their responses (The Basics)

What are vagal maneuvers? — Vagal maneuvers are ways doctors can affect a person's heartbeat without using medicines. For some vagal maneuvers, the doctor will press on a certain part of your body. For others, they will have you make a certain movement with your body.

Vagal maneuvers cause changes in your nervous system. Your nervous system then sends signals to your heart. These signals cause a response that affects your heartbeat.

Normally, a heartbeat happens when an electrical signal starts in a certain area in the heart. This electrical signal follows a set path to spread across the heart. As it spreads, the signal causes the heart muscle to squeeze in a normal way and at a regular rate. This causes the heartbeat.

Vagal maneuvers slow down the electrical signals that start a heartbeat. They can also slow down the electrical signals that spread across the heart. Both of these things can slow down the heartbeat.

What are examples of vagal maneuvers? — There are many different vagal maneuvers. The 2 that doctors use most often are "carotid sinus massage" and the "Valsalva maneuver."

What does carotid sinus massage involve? — To do carotid sinus massage, the doctor will have you lie down. Then they will press on a specific area in your neck. When your doctor does this, they are pressing on your carotid sinus. The carotid sinus lies under your skin in one of the carotid arteries (figure 1). The carotid arteries are the main blood vessels that bring blood to the brain. The doctor will press on your carotid sinus for about 5 to 10 seconds.

During carotid sinus massage, the doctor will monitor your blood pressure and heart activity. To monitor your heart activity, they will do an electrocardiogram (also called an "ECG") (figure 2).

Carotid sinus massage slows down the heartbeat and lowers your blood pressure. This maneuver can make you feel light-headed or like you might pass out.

Doctors usually don't do carotid sinus massage in people who have certain medical conditions, including carotid artery disease. In carotid artery disease, fatty clumps called "plaques" build up in the carotid arteries.

What does the Valsalva maneuver involve? — For the Valsalva maneuver, your doctor will have you breathe in and then try to breathe out hard, keeping your mouth and nose closed. This can feel like you are "bearing down" and trying to have a bowel movement.

The doctor will have you hold this position for up to 10 seconds. Then you can breathe normally again. After holding your breath, the doctor might ask you to lie down and have someone hold your legs up for 15 seconds.

During the Valsalva maneuver, the doctor will monitor your blood pressure and heart activity. To monitor your heart activity, they will do an electrocardiogram (also called an "ECG") (figure 2).

Why might my doctor use a vagal maneuver on me? — Doctors commonly use vagal maneuvers to diagnose or treat certain heart problems. These can include:

●Different kinds of tachycardia – Tachycardia is the medical term for when the heartbeat is faster than normal. Carotid sinus massage or the Valsalva maneuver can sometimes slow down or stop tachycardia, so the heart can beat normally again.

●Heart murmurs – The Valsalva maneuver is used in people who have a heart murmur. A heart murmur is an extra sound that doctors or nurses hear when they listen to the heart with a stethoscope. Your doctor or nurse might have you do the Valsalva maneuver when they listen to your heart. This will tell the doctor or nurse more about your heart murmur.

●A condition called "heart block" – In heart block, the electrical signals in the heart are slowed or stopped. Carotid sinus massage can help show your doctor where the block in your heart is.

Doctors also sometimes use these maneuvers to try to find out why a person has fainted. Carotid sinus massage can show if the fainting is from a condition called "carotid sinus hypersensitivity."

Are there other vagal maneuvers that doctors use? — Doctors sometimes use other vagal maneuvers, but these are rarely done. They involve putting a person's face in a bowl of ice water, or pressing on a person's eyeball. Both of these maneuvers slow down the heartbeat.

More on this topic

Patient education: Carotid artery disease (The Basics)
Patient education: Syncope (fainting) (The Basics)
Patient education: Tachycardia (The Basics)
Patient education: Heart block in adults (The Basics)
Patient education: Heart murmurs (The Basics)
Patient education: Wolff-Parkinson-White syndrome (The Basics)

Patient education: Syncope (fainting) (Beyond the Basics)
Patient education: Wolff-Parkinson-White syndrome (Beyond the Basics)