The effect of vagal stimulation on ventricular repolarization of normokalemic and hyperkalemic canine hearts was investigated. During the normokalemic state stimulation of the vagus decreased the amplitude of the T wave when the polarity of the wave prior to vagal activity was upright. When the control T waves were biphasic or inverted the effect of vagal stimulation was an increase in negativity. In all cases the T waves became upright and increased in amplitude during potassium (K+) infusion regardless of the initial T configuration prior to the infusion of the cation. As the plasma K+ levels were increasing the amplitude of these heightened T waves was further enhanced by vagal stimulation. It is concluded that vagal activity does effect ventricular repolarization and this effect is exaggerated as the plasma K+ level is progressively elevated.
- ventricular repolarization
- vagal activity T-wave changes
- vagal effect on mammalian ventricle
- Copyright © 1965 by American Physiological Society