What is the Valsalva maneuver?
The Valsalva maneuver is a particular way of breathing that increases pressure in the chest. It causes various effects in the body, including changes in the heart rate and blood pressure.
People may perform the maneuver regularly without knowing it. For example, they may use it when they push to initiate a bowel movement.
However, this technique can also be beneficial when people use it intentionally as it can regulate heart rhythms and help the ears to pop.
The physician Antonio Maria Valsalva first described the technique in the 1700s as a way to clear pus out of the ears.
How to do the Valsalva maneuver
To do the Valsalva maneuver, follow these steps:
- Inhale deeply and then hold your breath.
- Imagine that the chest and stomach muscles are very tight and bear down as though straining to initiate a bowel movement.
- Hold this position for a short time, usually about 10 seconds.
- Breathe out forcibly to release the breath rapidly.
- Resume normal breathing.
An alternative method involves lying down and blowing into an empty syringe for 15 seconds.
The Valsalva maneuver creates numerous effects in the body because it builds up the pressure in the pleural cavity, known as the intrapleural pressure.
This increased pressure can lead to the compression of the chambers of the heart and key blood vessels in the body, including:
- the aorta, which is the major artery that pumps oxygen-rich blood through the body
- the vena cava, which is the major vein that returns blood to the heart
The compression of the aorta initially causes the blood pressure to rise. A sensor in the carotid artery, called the baroreceptor, detects the increased blood pressure.
This activates parasympathetic fibers, which quickly reduce the heart rate and blood pressure. Doctors sometimes refer to this effect as vagaling.
The Valsalva maneuver reduces cardiac output, which is the amount of blood that the heart puts out with every beat. The individual may feel lightheaded or dizzy as a result.
Once the baroreceptor senses the decrease in heart rate and blood pressure, it will stimulate the sympathetic nervous system. This can cause a person's heart rate and blood pressure to increase, offsetting the parasympathetic effects.
However, when a person breathes out, this releases the compression on the heart, allowing it to fill back up with blood. Breathing out increases the pressure inside the aorta, stimulating the parasympathetic nervous system and decreasing the heart rate again.
