Open AccessVagus-Induced Changes in Ventricular Electrophysiology of the Dog Heart With and Without β-Blockade
Author(s) -
Jan P. Amlie,
Helge Refsum
Publication year - 1981
Publication title -
journal of cardiovascular pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.762
H-Index - 100
eISSN - 1533-4023
pISSN - 0160-2446
DOI - 10.1097/00005344-198111000-00006
Subject(s) - blockade , stimulation , repolarization , atenolol , refractory period , pentobarbital , electrophysiology , ventricle , heart rate , medicine , vagus nerve , anesthesia , vagus nerve stimulation , cardiology , blood pressure , receptor
We tested the electrophysiologic effects of vagus stimulation in six dogs in the presence or absence of beta-adrenoreceptor blockade. Monophasic action potentials were obtained by the suction electrode technique and programmed electrical stimulation was used to determine heart rate-independent changes in 50 and 90% repolarization times and in the effective (V-ERP) and functional (V-FRP) refractory periods of the right ventricle. Vagus stimulation decreased heart rate both in the presence and in the absence of beta-adrenoceptor blockade. It also increased action potential duration and refractoriness during high sympathetic tone induced by pentobarbital anesthesia. The effect is probably due mainly to inhibition of beta 1-adrenoreceptors, since it was decreased by beta 1-adrenoceptor blockade with atenolol. We conclude that stimulation of the vagus has antiarrhythmic effects in ventricles under high sympathetic stimulation.