Valsalva Maneuver

Valsalva
Valsalva maneuver. Science Photo Library/Getty Images

The Valsalva maneuver is a technique which is useful for transiently increasing the tone of the vagus nerve, and for transiently increasing the pressure in the throat, sinuses, and inner ears. The Valsalva maneuver has several practical uses in medicine, and in everyday life.

For instance, cardiologists often recommend the Valsalva maneuver to their patients who have episodes of supraventricular tachycardia (SVT), as a means of stopping the arrhythmia when it occurs.

The Valsavla maneuver is also a useful technique for scuba divers, people with hiccups — and many others.

How The Valsalva Maneuver Is Done.

The Valsalva maneuver (which is named after A.M. Valsalva, who first described it 300 years ago as a way to expel pus out of the middle ear), is performed by attempting to exhale forcefully against a closed airway. This can be done by keeping your mouth closed and pinching your nose, while trying to exhale forcefully. This maneuver immediately increases pressure in the sinuses and inner ears. To achieve an increase in vagal tone, the forced attempt to exhale should be be maintained for 10 - 15 seconds.

What Does The Valsalva Maneuver Do?

The Valsalva maneuver greatly increases pressures inside the nasal sinuses, and especially in the chest cavity. In simple terms, the elevated chest pressure stimulates the vagus nerve and increases vagal tone. However, the Valsalva maneuver actually produces a fairly complex series of physiological events that doctors have employed over the years for several purposes.

From a physiological standpoint, a 15-second Valsalva maneuver has four distinct phases:

  • In  phase 1, acutely blowing against a closed airway increases the pressure inside the chest cavity, which immediately pushes blood from the pulmonary circulation into the left atrium of the heart. So, for a few seconds the amount of blood being pumped by the heart increases. (Read about the heart’s chambers and valves.)
  • In  phase 2, the amount of blood being pumped by the heart suddenly drops. This drop in cardiac output occurs because because the increased pressure in the chest cavity prevents any more blood from returning to the chest from the rest of the body, and therefore from returning to the heart. To compensate for this drop in cardiac output, the body’s blood vessels constrict, and blood pressure rises. This elevated blood pressure continues for the duration of the Valsavla maneuver.
  • Phase 3  occurs immediately upon resumption of normal breathing. The pressure within the chest suddenly drops, and the pulmonary circulation re-expands and fills with blood again. However, during this re-expansion of the chest (which lasts for 5 - 10 seconds), the cardiac output may drop further.
  • Finally, in  Phase 4  the blood flow to the heart and lungs returns to normal, as does the cardiac output and blood pressure.

What Is the Valsalva Maneuver Used For?

Doctors find the Valsalva maneuver useful in distinguishing among various kinds of valvular heart disease. Most heart murmurs will diminish during phase 2 of the Valsalva maneuver, since the heart is not pumping much blood at this time. But the murmurs associated with both mitral valve prolapse and hypertrophic cardiomyopathy will often increase during phase 2 of the Valsalva maneuver.

Speaking more practically, the chief medical use of the Valsalva maneuver is to suddenly increase vagal tone (which also occurs mainly during phase 2). Increasing vagal tone slows the conduction of the cardiac electrical impulse through the AV node, and this transient slowed conduction is quite useful in terminating some types of SVT (in particular, AV-nodal reentrant tachycardia and  atrioventricular reentrant tachycardia). (Read about the heart’s electrical system.)

This means that people who have recurrent episodes of these varieties of SVT (which are the two most common types) are often able to quickly and reliably stop the arrhythmia whenever it occurs by employing the Valsalva maneuver.

The Valsalva maneuver is commonly used by scuba divers during descent, to equalize the pressures in the middle ear with the elevated ambient pressures under water.

The Valsalva maneuver may help doctors to detect injury to the cervical spine. This maneuver transiently increases intraspinal pressures — so if there is nerve impingement (for instance, as a result of a damaged intervertebral disc), any pain being caused by the injury may momentarily increase.

Urologists may use the Valsavla maneuver to help them diagnose stress incontinence, since the elevated abdominal pressure this technique produces can provoke urinary leakage.

And many people find that they can get rid of an episode of hiccups by performing a Valsalva maneuver. It may be that this is the most common and the most practical application of the Valsalva maneuver.

A Word From Verywell

The Valsalva maneuver is a method of transiently increasing pressure within the sinuses and middle ears, and of increasing vagal tone. It has practical applications in the practice of medicine, and in daily life.

Sources:

Appelboam A, Reuben A, Mann C, et al. Postural Modification to the Standard Valsalva Manoeuvre for Emergency Treatment of Supraventricular Tachycardias (REVERT): a Randomised Controlled Trial. Lancet 2015; 386:1747.

Page RL, Joglar JA, Caldwell MA, et al. 2015 ACC/AHA/HRS Guideline for the Management of Adult Patients With Supraventricular Tachycardia: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation 2016; 133:e506.

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