A<unk>  is an action used to stimulate the parasympathetic nervous system by activating the vagus nerve. The vagus nerve is the longest nerve of the autonomic nervous system and helps regulate many critical aspects of human physiology, including heart rate, blood pressure, sweating, and digestion through the release of acetylcholine. Common maneuvers that activate the vagus nerve include the Valsalva maneuver and carotid sinus massage, which can serve diagnostic or therapeutic functions.
Vagal maneuver
Epley maneuver
Pacing 
Pringle manoeuvre
Zavanelli maneuver
Vagus nerve stimulation
Barlow maneuver
Jendrassik maneuver