During the Valsalva maneuver (i.e., exhaling against a closed glottis or bearing down as though to defecate), intrathoracic pressure increases and leads to incr

During the Valsalva maneuver (i.e., exhaling against a closed glottis or bearing down as though to defecate), intrathoracic pressure increases and leads to increased arterial pressure as a result of increased afterload. It is easily done by having the patient take a deep breath, put their thumb in their mouth with closed lips, and attempt to exhale without expelling any air.