The heart has long been recognized as crucial to life. However, throughout history, the heart has acquired an almost sacred quality that transcends even its importance to the physical body.
Our language is filled with references to the heart, from "brokenhearted" to "the heart of the matter." Although we think with our brains, we "feel" with our hearts; opinions we hold most dear are "heartfelt." The heart is the repository of romantic love, most tangibly demonstrated by the classic valentine heart, despite its structural inaccuracy. Now, of course, we also comprehend the central role of the heart and blood vessels in our overall vitality: "cardiovascular fitness" has become virtually synonymous with good health.
The ancients were aware of the role of the heart and circulation in the normal functioning of the body. As long as 4,500 years ago, Huang Ti, the Yellow Emperor of China, wrote: "The heart influences the face and fills the pulse with blood" and "The blood current flows continuously in a circle and never stops." Early Egyptian writings from about 1550 B.C. referred to the heart as a "well" with vessels: "Everywhere he feels his Heart," it was observed in the Ebers papyrus, "because its vessels run to all his limbs." In 400 B.C, Greek writers noted that the heart is a muscle and is a part of the vascular system (although at least some writers seemed to think that the vessels contained air rather than blood); they described the pericardium, the heart valves, and the characteristics of the pulse. Centuries later, many o conclusions were proved incorrect but the foundations of knowledge were slowly being laid.