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. 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 has other uses as well.

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 the mouth closed and pinching the nose, while trying to breath out forcefully. To achieve an increase in vagal tone, the forced attempt to breathe out should be be maintained for 10 - 15 seconds.

What Does The Valsalva Maneuver Do?

This 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 “pumps” blood from the pulmonary circulation into the left atrium of the heart. So, for a few seconds the amount of blood 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 drops. This drop in cardiac output occurs because because the increased pressure in the chest cavity prevents blood from returning to the chest, and therefore to the heart, from the rest of the body. 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 breathing. The chest pressure suddenly drops, and the pulmonary circulation re-expands and fills with blood again. During this re-expansion, however (which lasts for 5 - 10 seconds) the cardiac output may drop further.
  • In Phase 4 the blood flow to the heart and lungs finally returns to normal, as does the cardiac output and blood pressure.

What Is The Valsalva Maneuver Used For?

The chief medical use of the Valsalva maneuver is to increase vagal tone (which occurs mainly during phase 2). Increasing vagal tone slows the conduction of the cardiac electrical impulse through the AV node, and is quite useful in terminating some types of SVT (in particular, AV-nodal reentrant tachycardia and atrioventricular reentrant tachycardia).

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

The Valsalva maneuver may also help doctors distinguish among various types of heart murmurs. For instance, while most murmurs diminish during phase 2 of the Valsalva maneuver, the murmurs associated with mitral valve prolapse and hypertrophic cardiomyopathy may increase. 

The Valsalva maneuver is commonly used by divers to normalize the pressures in the middle ear.

The Valsalva maneuver may help detect injury to the cervical spine. The maneuver 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 transiently increase.

Urologists may use the Valsavla maneuver to help them diagnose stress incontinence.

And many people find that they can get rid of an episode of hiccups by performing a Valsalva maneuver.

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.

Waxman MB, Wald RW, Sharma AD, et al. Vagal Techniques for Termination of Paroxysmal Supraventricular Tachycardia. Am J Cardiol 1980; 46:655.

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