The heart symbolizes both, however, as it turns out it has more similarities than just the symbol. Although it is still the #1 killer in the U.S. and great advancements have been made in the medical treatment of heart disease, the greatest breakthrough is happening now in understanding the role of emotions and stress and how these factors can be turned around not with another pill but by yourself through positive thinking. According to Dr. Rollin McCraty of the Institute of HeartMath, research shows that the heart is more than a muscle but it thinks and actually sends messages to the brain and responds to emotions. In the past psychologists maintained that emotions were expressions generated by the brain only but today it has been proven over and over that emotions affect all organs but especially the heart.
The heart, the most important muscle in our body, is constantly having a 2-way dialogue with our brain and we now know the heart sends more information to the brain than vice versa. Emotions can cause erratic heart rhythms (one of the most common reasons for heart failure). There are two main heart disease categories, the first, heart attack which is caused when the heart muscle is robbed of its vital blood supply (caused by a blockage). The other main category is classified as cardiac arrest which is attributed to irregular heartbeat and when the heart actually stops pumping blood properly around the body and the person stops breathing normally, this is the heart failure that is most often the consequence of stress or strong emotions. Studies have found that the risk of developing heart disease is significantly higher with people experiencing negative emotions such as anger, frustration, etc. and if we consistently experience these emotions they can lead to irregular heartbeat and other serious illness. Conversely when we experience emotions like love, appreciation and compassion the heart has a very smooth and even heartbeat. The Mayo Clinic has termed the temporary disruption of a person's heart rhythm brought on by stress and negative emotions as "broken heart syndrome".
Broken hearts were what first fueled the growth of Valentine's Day and now science is learning that some of the same emotions like lost love may lead us to a way to improve heart health by learning how to shift our negative emotions to positive ones, returning our hearts to a natural and even rhythm.