The influence of the parasympathetic nervous system on atrioventricular conduction.

IN THIS brief review I will attempt to amalgamate current findings with important historical concepts about the influence of the parasympathetic nervous system on atrioventricular (AV) conduction. I first will describe the innervation of the AV nodal region. Then I will discuss the influence of acetylcholine and associated cholinergic agents, the effects of vagal stimulation, and the role of the vagus in the genesis of arrhythmias. Finally, I will describe briefly certain cardiovascular reflexes that affect AV conduction. I have not attempted to provide an exhaustive list of references; rather, the most relevant works were arbitrarily selected to illustrate specific points. I regret that many worthy contributions had to be omitted.