Five Quarts: A Personal and Natural History of Blood by Bill Hayes Page A

obtained not by hand but through a monitor attached to the blood pressure cuff or a sensor clipped like a clothespin to the index finger. These digital devices, sensitive enough to detect the heart rate through capillaries in the skin, operate just like the pulse calculators built into sports watches, stationary bikes, and so forth. They’re used in the interest of speed, accuracy, convenience, and, I’m told, patient comfort. Some people do not like to be touched. While there’s no such high-tech revolution yet under way at Dr. Knox’s office, Steve’s doctor visits are different. In an office gone digital, the haste with which his body is stripped of its secrets—weight, body temperature, heart rate—is dizzying. Every second shaved from an exam is, of course, money saved by an HMO. But at a time when patients are encouraged to turn to WebMD with the questions their family doctor didn’t have time to answer, it strikes me that pulse taking by hand remains an uncorrupted tradition, one with strong roots in the classical age.
    In ancient Greece the art of feeling the pulse (
sphygmopalpation,
from the Greek
sphygmos,
for “throb”) was first taught by the physician Praxagoras, a contemporary of Hippocrates, one of the earliest fathers of Western medicine. Praxagoras’s star pupil, Herophilus (335–280 B.C. ), was the first physician to methodically time the pulse. He used a primitive water clock that had been invented to time the speeches of orators. Erasistratus, Galen’s phantom bloodletting rival, is credited with incorporating the pulse into clinical exams. His first diagnosis: lovesickness, in a young man whose pulse quickened dangerously whenever his crush drew near. The attention paid the pulse at that time is all the more impressive given that the ancients were missing huge pieces of the puzzle. Though these healers knew they had their fingers on the pulse of the body’s innermost workings, they did not understand the actual role of the heart in circulating blood any better than they knew the distinction between veins and arteries.
    Not until the intellectual watershed of the Renaissance did this begin to change. A major upheaval in how the body was viewed required first the systematic dismantling of the hallowed teachings of Galen. A key figure in this deconstruction was the Belgian anatomist Andreas Vesalius, who, in his illustrated seven-volume masterwork of 1543, soundly disproved two hundred of Galen’s factual errors. No, the liver did not distribute blood throughout the body. No, blood did not “sweat” from the right side of the heart to the left. No, animal anatomy wasn’t interchangeable with human. And on and on. Vesalius, among others, paved the way for Great Britain’s William Harvey, who in 1628 turned the world on its ear: Blood circulates, he announced in his historic
An Anatomical Essay on the Movement of the Heart and Blood in Animals.
For its role in launching the modern era of medicine, contemporary historians have called Harvey’s book one of the three greatest works in the English language—all three, curiously, dating from the early 1600s—alongside the King James version of the Bible (1611) and the First Folio Edition of Shakespeare’s plays (1623). By comparison with these other two works, Harvey’s tour de force is small in size (five by seven inches), short in length (seventy-two pages), and written in deceptively simple language.
    “The movement of the blood in a circle is caused by the beat of the heart,” he declared, summing up in one sentence his entire theory of the circulatory system. Then, as if to head off any
But what about . . . ?
from the unconvinced, Harvey added, “This is the only reason for the motion and beat of the heart.”
    Through animal vivisection, human dissections, and observations of living patients, Harvey poked more holes in Galenism. Blood did not ebb and flow within the same vessels, as the Greek physician had taught. Instead, the