Manoeuvres to combat vasovagal syncope

A 32-year-old female patient underwent cardiovascular reflex assessment for recurrent syncope and pre-syncope, clinically of vasovagal origin. A vasovagal reaction, with prodromal pallor and sweating, occurred while the patient was standing motionless in the cardiovascular laboratory. The patient sat down on a chair with her head between her knees ( Fig. 1A ). After standing up, the hypotension returned and the patient squatted ( Fig. 1B ). After standing up, when hypotension returned again, she was instructed to cross her legs and tense leg, buttock and abdominal muscles ( Fig. 1C ), which successfully aborted the pre-syncope. Non-invasive arterial pressure displayed under three conditions described in the text—panels A, B and C Sitting down with head bent between the knees is the classical counter manoeuvre [1] to combat vasovagal (pre-) syncope. Squatting and leg crossing combined with muscle tension [2] are recently introduced combative manoeuvers. The stabilizing effects on blood pressure of the manoeuvres are caused by increasing central venous pressure and refilling of the heart by mechanical pressure on the splanchnic veins ( Fig. 1A ) and activation of the muscle pump ( Fig. 1B, C ).