Cohérence cardiaque, cardiac coherence. Is a growing science of the relationship between heart and mind (or heart and brain!) It is different from the relaxation response, in that relaxation favors the activity of the parasympathetic branch of the central nervous system only. This lowers the heart and also, heart rate variability.
Heart rate variability (HRV) is a new predictor for a growing number of stress-related conditions, like for example, cardiovascular disease. It was once thought that the heart beats a steady beat like a drum. However, we now know that it is not the case. The variability between heart beats changes frequently during the day, in response to external stress, physiological function, and also emotions. The greater degree of HRV, the better your system is a adapting and responding to stress.
The important of cardiac coherence lies with this analogy: imagine you try to drive your car with one foot on the gas and the other on the break. This is the same with your central nervous system. It has two branches, sympathetic and parasympathetic. Fear is the break, and motivation is the gas. The nature of the game is to find a synchronous, or harmonious pattern between the two. And to achieve a harmonious pattern between moving forward and stepping back. Kind of like dancing with a partner ;)
The anterior cingulate gyrus, a higher-processing center of the brain, regulates heart rate and blood pressure, and is also involved in decision making, impulse control, reward, and emotion. It is thought to be the advanced brain also responsible for compassion and social interaction, as opposed to the amygdala which is the primitive brain responsible for our survival instinct and fear. It is interested to start making some of these connections, namely with empathy and compassion, and its effects on your physiological health. Is being genuinely empathetic good for your health?
As is most aspects of nature and life, there is not one dominant controller. This system is not simply the brain that is the master of the heart. Science is now showing that the heart itself can communicate with the brain. Perhaps lighting up certain areas in the brain....and this notion of lighting up? So elegant indeed as a metaphor :) What better to start the holiday season with this in heart and mind.
Therefore, cardiac coherence is not so much about relaxation, as it is about finding synchronicity within your central nervous system. A field of neuro, and heart science, and I am quite intrigued by.