Written by the HeartMath Institute

1.
Heart Focus: Focus your attention on your heart area. Breathe a little deeper than normal, in for 5 or 6 seconds and out 5 or 6 seconds. You may find that placing your hand over your heart helps you maintain your focus there.
2.
Heart Breathing: Now imagine while breathing that you’re doing it through your heart. Picture yourself slowly breathing in and slowly breathing out through your heart area.

(Maintaining your focus and breathing through the heart area leads you naturally into a state of ease. When you’re ready to proceed with the rest of your day, you’ll do so with more energy and resilience for future challenges.)
The scientific term for this simple and quick tool is psychophysiological coherence.

Physiological Coherence
“Coherence is the state when the heart, mind and emotions are in energetic alignment and cooperation,” according to HeartMath Institute Research Director Dr. Rollin McCraty. “When the physiological coherence mode is driven by a positive emotional state, we call it psychophysiological coherence.”

Those who’ve practiced Heart-Focused Breathing through the years say they have experienced: a sense of being uplifted and alive; more peaceful and less rushed in their busy lives; a deeper heart connection within and with others.

Keywords; Physiological Coherence, Heart Breathing

https://www.heartmath.org/articles-of-the-heart/the-math-of-heartmath/heart-focused-breathing/