Cardiac innervation ( contin At rest moderate amount of tonic discharge in the cardiac sympathetic nerves a good deal of tonic vagal discharge (vagal tone) When the vagi are cut in experiment animals. the heart rate risesCardiac innervation (contin.) ➢ At rest ➢ moderate amount of tonic discharge in the cardiac sympathetic nerves ➢ a good deal of tonic vagal discharge (vagal tone) ➢ When the vagi are cut in experiment animals, the heart rate rises