Disturbed autonomic nervous 'balance' of the sympathetic nervous and vagal outflows to the heart potentiates the experimental development of ventricular arrhythmias in laboratory animals. For some time the best evidence for the occurrence of a similar phenomenon in humans was provided by the long QT interval syndrome, sufferers of which are very prone to develop serious ventricular arrhythmias and in whom evidence exists of abnormal anatomy and function of the cardiac sympathetic nerves. Recently the case for disturbed autonomic function causing clinical arrhythmias has become more broadly based. Reduced baroreflex sensitivity after myocardial infarction, and low heart rate variability, both of which rest largely on vagal underactivity, have been shown to be associated with substantially increased risk of subsequent sudden death.
Esler M.
Baker Medical Research Institute, Prahran, Australia.
Clin Auton Res. 1992 Apr;2(2):133-5.
