Valsalva Maneuver

Valsalva maneuver. Science Photo Library/Getty Images

The Valsalva maneuver is a technique used mainly to transiently increase the tone of the vagus nerve, though it has other effects. Cardiologists often advise their patients to use the Valsalva maneuver to help stop an episode of supraventricular tachycardia - SVT. However, 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. The forced expiration is supposed to be maintained for 10 - 15 seconds.

What Does The Valsalva Maneuver Do?

This maneuver greatly increases pressures inside the chest cavity - which 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 “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 cardiac output drops. This occurs because because the increased pressure in the chest cavity prevents blood from returning to the heart from the circulation. To compensate for the drop in cardiac output, blood vessels constrict and blood pressure rises. This 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 heart and lungs return to normal.

    What Is The Valsalva Maneuver Used For?

    The chief medical use of the Valsalva maneuver is to increase vagal tone (which occurs chiefly 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).

    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), pain may 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.


    Waxman MB, Wald RW, Sharma AD, et al. Vagal techniques for termination of paroxysmal supraventricular tachycardia. Am J Cardiol 1980; 46:655.

    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.

    Continue Reading