vagotonus /vā′gətō″nəs/ [L, vagus + Gk, tonos, tension] , an abnormal increase in parasympathetic activity caused by stimulation of the vagus nerve, especially bradycardia with decreased cardiac output, faintness, and syncope. Vagotonus may occur in suctioning the oropharynx of a newborn as the syringe, laryngoscope blade, or catheter is inadvertently pressed on the back of the throat, stimulating the nerve. It also occurs in some women after surgical treatment or simple manipulation of the uterine cervix.
