"forced expiration against a closed glottis.
increases intraocular pressure and the risk of retinal detachment.
Uses:
1) to arrest episodes of supraventricular tachycardia.
2) to diagnose heart abnormalities
especially when used in conjunction with echocardiogram.
e.g.it increases the intensity of hypertrophic cardiomyopathy murmurs
but decreases the intensity
of most other murmurs.
3) Aid in al diagnosis of problems in the nerves of the cervical spine. It increases intraspinal pressure . Neuropathies or radicular pain may be felt or exacerbated.
4) In diving
the Valsalva maneuver is often used on descent to equalise the pressure in the middle ear
to the ambient pressure."