Effect of Autonomic Activity on Pacemaker Function and Conduction

  • E. Neil Moore
  • Joseph F. Spear

Abstract

The effect of the autonomic nervous system on impulse formation and conduction within the heart is well known. The time course of the effect of a brief vagal volley on sinus node cycle length was first measured by Brown and Eccles in 1934 (93). Subsequent workers described the discrete effect of phasic changes in vagal tone on spontaneous sinus rhythm in both animals and man during complete atrioventricular conduction block (40,443,448, 490,685). Several laboratories have defined the time course of autonomic stimulation on atrioventricular conduction (186,542,778,872), however there have been few studies concerning the role of phasic variations in autonomic tone on arrhythmia production. The present studies describe effects of phasic stimulation of the sympathetic and parasympathetic nervous system upon atrioventricular conduction in the anesthetized open-chest dog.
Fig. 1

The influence of brief vagal stimulation on AV nodal conduction time. Bipolar electrograms were recorded from the right atrium (RA), the bundle of His (BH), and the right ventricle (RV), simultaneously with a lead II electrocardiogram (II). In the His bundle electrogram, a and h indicate septal and His bundle activation respectively. The a-h intervals are indicated in msec for the subsequent beats. V indicates the timing of a 100 msec train of stimuli delivered to the left vagus. Timing signal t denotes 100 msec intervals. V-h indicates the interval between the beginning of the vagal stimulation and the His bundle activation of the subsequent beat. a-h indicates the atrial to bundle of His conduction time for the first beat following vagal stimulation.

Keywords

Assure 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Martinus Nijhoff Medical Division 1978

Authors and Affiliations

  • E. Neil Moore
  • Joseph F. Spear

There are no affiliations available

Personalised recommendations