A pressor response and tachycardia during successive water swallows via straw

Swallowing is a behavior that requires precise timing and coordination with breathing. Recent research during sleep suggests that it also involves autonomic nervous system regulation to maintain homeostasis. The balance between sympathetic (spinal) and parasympathetic (vagal) outflow is responsible for modulating blood vessel tone, heart rate, and cardio-respiratory coupling. However, changes in blood pressure and heart rate during ingestion, and particularly swallowing, remain unclear. The purpose of the present study was to investigate changes in blood pressure and heart rate with an increasing number of successive swallows. In subjects of both sexes (ages 19–25), we performed arterial blood pressure measurements using a non-invasive dual-finger cuff system (plethysmography), which allows for the recording and measurement of continuous beat-to-beat blood pressure and heart rate signals. Concomitantly, non-invasive wireless electrodes placed over the masseter and submental muscles were used to record and identify swallows. After 15 minutes of quiet resting conditions, participants were instructed to perform three trials of self-delivered water via straw: a) 1 swallow, b) 2 swallows, and c) 3 swallows in a row. Sequential swallows (>2) promoted a transient and significant pressor response and tachycardia (p < 0.05). Our data suggest that there is important autonomic modulation during swallowing to maintain homeostasis and may serve as a mini-arousal to prevent aspiration. Funded by NIH Grants: NS110169, HD110951 This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.