Abstract
The effect of Lanatoside C on ventricular automaticity was studied in six patients with complete heart block and artificical pacemaker stimulation. A suppressive action of Lanatoside C on ventricular automaticity may be produced indirectly by diminishing an increased cardiac sympathetic outflow. However, the present observation of an unchanged sinus rate after the administration of Lanatoside C does not support such a mechanism. The possibility of a direct depressive effect of the drug on ventricular automaticity might therefore be considered.