“…However, extrapolation of this phenomenon to the whole myocardium [9,12,13] can be erroneous, because heart ventricles are practically devoid of vagal terminals [10] and insensitive to acetylcholine [2]. The reason of this possibly erroneous although widespread view can be indirect decrease of ventricular contractility produced by vagal stimulation accompanied by vagal inhibition of sympathetic influences on the heart [7], cholinergic constriction of coronary vessels [8], moderation of the atrial pumping function [5,11], and bradycardia [14] associated with decreased afterload [5]. However, all these phenomena do not agree with escape rhythm under conditions of vagal stimulation [5,10] and postvagal potentiation of myocardial automaticity and contractility [5,10].…”