Identification of the optimum vagal manoeuvre technique for maximising vagal tone

Abstract

OBJECTIVES: This study sought to determine the most effective technique for Valsalva Manoeuvre (VM) and Human Dive Reflex Manoeuvre (HDR) generation of vagal tone. METHODS: We conducted a repeated-measures trial of healthy adult volunteers from a university campus, aged 18-56 years, in sinus rhythm. Participants were randomised to VM (in supine or Trendelenberg postures) and HDR (supine or sitting postures) sequentially. Participants performed three trials of each technique, in random order, with a continuous ECG recording. Single-blinded analysis of ECG data was conducted. Mean differences between premanoeuvre and postmanoeuvre R-R intervals and heart rates were calculated for each posture ..