The brain and the heart are connected via the autonomic peripheral nervous system, which is not under conscious control and regulates organ function.
The sympathetic branch (fight or flight), raises heart rate, blood pressure etc. whereas the parasympathetic branch slows heart rate, lowers blood pressure etc. The goal for optimal health is to have the two branches balance each other.
So, learning how to control the heart can make a huge difference in our ability to come to peace with the emotional brain.
These ideas come from a book, The Instinct to Heal - Curing Depression, Anxiety, and Stress without Drugs and without Talk Therapy, by David Servan-Schreiber, M.D., PhD
It is said that we are happiest when we follow our heart, so learning to hear what our heart is telling us can be very valuable indeed.
Amen. In my most popular speech and signature story, Hear Your Heart, I talk about how hearing your heart can actually save your life. It saved mine.