'Autonomic conflict': a different way to die during cold water immersion?

J Physiol. 2012 Jul 15;590(14):3219-30. doi: 10.1113/jphysiol.2012.229864. Epub 2012 Apr 30.

Abstract

Cold water submersion can induce a high incidence of cardiac arrhythmias in healthy volunteers. Submersion and the release of breath holding can activate two powerful and antagonistic responses: the 'cold shock response' and the 'diving response'. The former involves the activation of a sympathetically driven tachycardia while the latter promotes a parasympathetically mediated bradycardia. We propose that the strong and simultaneous activation of the two limbs of the autonomic nervous system ('autonomic conflict') may account for these arrhythmias and may, in some vulnerable individuals, be responsible for deaths that have previously wrongly been ascribed to drowning or hypothermia. In this review, we consider the evidence supporting this claim and also hypothesise that other environmental triggers may induce autonomic conflict and this may be more widely responsible for sudden death in individuals with other predisposing conditions.

Publication types

  • Review

MeSH terms

  • Animals
  • Arrhythmias, Cardiac / etiology*
  • Cold Temperature / adverse effects*
  • Cold-Shock Response
  • Death, Sudden, Cardiac / etiology*
  • Drowning / physiopathology*
  • Heart / innervation*
  • Heart / physiopathology
  • Humans
  • Hypothermia / physiopathology
  • Parasympathetic Nervous System / physiology
  • Respiration
  • Sympathetic Nervous System / physiology