Valsalva maneuver

The Valsalva maneuver is performed with the patient supine or in a semirecumbent position and instructed to exhale forcefully against a closed glottis after a normal inspiratory effort (ie, at tidal volume). Signs of adequacy include neck vein distension, increased tone in the abdominal wall muscles, and a flushed face. The patient should maintain the strain for 10 to 15 seconds and then release it and resume normal breathing.
A modified Valsalva maneuver involves the standard strain (40 mmHg pressure for 15 seconds in the semirecumbent position at 45 degrees) immediately followed by lowering the trunk to a supine position with passive leg raise at a 45 degree angle for 15 seconds. The modified Valsalva maneuver has been shown to be more successful in restoring sinus rhythm for patients with supraventricular tachycardia.