Contribution of vagal tone to initiation and termination of ventricular tachycardia: report of three cases.

The role of vagus nerve in modulating ventricular dysrhythmia has recently been emphasized. We report here on two patients who had ventricular tachycardia (VT) which was terminated and converted to sinus rhythm by either eyeball pressure or a Valsalva maneuver. Moreover, in one of these patients and in a third patient, VT was initiated following administration of vagolytic agents. This supports the view that the parasympathetic nervous system does modulate the electrical activity of the human ventricle.