Read Online Heart: An American Medical Odyssey by Dick Cheney, Jonathan Reiner - Free Book Online Page B
Authors: Dick Cheney, Jonathan Reiner
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oval opening in the drape exposing his wrist painted orange with antiseptic scrub. Two palm-sized patches on his chest are attached to the defibrillator perched on a rolling cart near the wall, its reassuring beeps quickly fading into familiar white noise. I dry my hands with a towel and slip into the sleeves of a sterile gown that unfolds with a quick downward flip. I pull on a pair of gloves, the latex issuing its characteristic thwack as I release each cuff. A nurse ties the back of my gown, and I step toward the patient preparing for a routine procedure that not long ago was impossible.
• • •
For millennia, the human heart remained mysterious and inviolable, the center of the physical body and the immortal soul, the sacred wellspring of character, intelligence, and valor.
In ancient Egypt, the heart was the only internal organ left in place during mummification, believed indispensable in Duat, the underworld, where it would be weighed against a feather, the symbol of Maat, goddess of truth and justice. Should the scales balance, the deceased would be deemed worthy of admission to the afterlife. If, however, the heart was heavy, Ammit, the devourer of the dead, a fearsome creature with the head of a crocodile, body of a lion, and hindquarter of a hippopotamus, would consume the heart, leaving the soul without rest.
Although the Greeks of the fourth century B.C. knew that the heart had four chambers and understood its anatomical relationship to the large blood vessels arising from it, knowledge they derived principally from the dissection of animals, luminaries like Aristotle and Hippocrates did not understand the organ’s role in the circulation of blood. Aristotle believed that the heart was the center of human consciousness, and in many of the languages that evolved over the millennia, the word heart represents more than just the cardiac structure. Mandarin uses the same character (xīn) for both “heart” and “mind.” The English word courage is derived from the Latin cor (heart), as are its Italian, French, and Portuguese counterparts, and the word core literally means heart.
At the beginning of the third century B.C., human dissection was permitted in Alexandria, and it was there that important advances were made in understanding the structure of the vascular system. The Greek physician Herophilus correctly considered the atria part of the heart (as opposed to part of the vessels leading into the heart) and was the first to describe the differences between the thick-walled arteries and the thin-walled veins, noting correctly that the vessel exiting the right ventricle was an artery, not a vein, and the vessels leading into the left atrium were veins, not arteries. Herophilus is also credited as being the first physician to count the pulse, though he incorrectly believed that the pulsations were caused by the contraction of the arteries.
Galen, a second-century Greek physician who lived in the Roman Empire and whose writings would dominate medicine for fifteen hundred years, believed that the heart was the source of the body’s heat and moved pneuma (air, vital spirits) around the body. Although Galen did not believe that the heart was a muscle, he clearly understood its unique attributes:
Its flesh is hard and not easily injured, being composed of fibres of many different kinds, and because of this, even if it would appear to be like muscles it is clearly different from them. . . . And in its hardness, tone, or tension and general strength and resistance to injury, the fibres of the heart much surpass all other fibres. For no organ functions so continuously, or moves with such force as the heart.
The classic view of circulation, which would perpetuate into the seventeenth century, can be summarized. The veins, it was thought, were the principal blood vessels and arose from the liver; the arteries contained only a small amount of blood mixed with pneuma; the heart provided the body’s heat
• • •
For millennia, the human heart remained mysterious and inviolable, the center of the physical body and the immortal soul, the sacred wellspring of character, intelligence, and valor.
In ancient Egypt, the heart was the only internal organ left in place during mummification, believed indispensable in Duat, the underworld, where it would be weighed against a feather, the symbol of Maat, goddess of truth and justice. Should the scales balance, the deceased would be deemed worthy of admission to the afterlife. If, however, the heart was heavy, Ammit, the devourer of the dead, a fearsome creature with the head of a crocodile, body of a lion, and hindquarter of a hippopotamus, would consume the heart, leaving the soul without rest.
Although the Greeks of the fourth century B.C. knew that the heart had four chambers and understood its anatomical relationship to the large blood vessels arising from it, knowledge they derived principally from the dissection of animals, luminaries like Aristotle and Hippocrates did not understand the organ’s role in the circulation of blood. Aristotle believed that the heart was the center of human consciousness, and in many of the languages that evolved over the millennia, the word heart represents more than just the cardiac structure. Mandarin uses the same character (xīn) for both “heart” and “mind.” The English word courage is derived from the Latin cor (heart), as are its Italian, French, and Portuguese counterparts, and the word core literally means heart.
At the beginning of the third century B.C., human dissection was permitted in Alexandria, and it was there that important advances were made in understanding the structure of the vascular system. The Greek physician Herophilus correctly considered the atria part of the heart (as opposed to part of the vessels leading into the heart) and was the first to describe the differences between the thick-walled arteries and the thin-walled veins, noting correctly that the vessel exiting the right ventricle was an artery, not a vein, and the vessels leading into the left atrium were veins, not arteries. Herophilus is also credited as being the first physician to count the pulse, though he incorrectly believed that the pulsations were caused by the contraction of the arteries.
Galen, a second-century Greek physician who lived in the Roman Empire and whose writings would dominate medicine for fifteen hundred years, believed that the heart was the source of the body’s heat and moved pneuma (air, vital spirits) around the body. Although Galen did not believe that the heart was a muscle, he clearly understood its unique attributes:
Its flesh is hard and not easily injured, being composed of fibres of many different kinds, and because of this, even if it would appear to be like muscles it is clearly different from them. . . . And in its hardness, tone, or tension and general strength and resistance to injury, the fibres of the heart much surpass all other fibres. For no organ functions so continuously, or moves with such force as the heart.
The classic view of circulation, which would perpetuate into the seventeenth century, can be summarized. The veins, it was thought, were the principal blood vessels and arose from the liver; the arteries contained only a small amount of blood mixed with pneuma; the heart provided the body’s heat
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