@bluegirl6 Yes, there is such a condition known in the medical community called 'dysautonomia,' Vagal tone is widely accepted as a factor in how the heart functions, but also in how other organs function. The Vagus nerve regulates the 'calming' influence of the parasympathetic nervous system, whereas the sympathetic nervous system enables higher capacity than one would normally call on...the fight-or-flight response when the need is urgent. The sympathetic nervous response is associated with the amygdala in the brain (the fear center), and the adrenal cortex. People who are continually stressed have a higher baseline stress response with more epinephrine circulating and more cortisol (which is supposed to help healing if you get wounded in a fight or by a tiger/bear).

I tried various methods to soothe the Vagus nerve, or to restore its tone, and had mediocre results. Stroking the tragus on both ears helped some, but it was hardly worth my time since it didn't stop atrial fibrillation.