The Curious History of the Heart by Vincent M. Figueredo

Author:Vincent M. Figueredo
Language: eng
Format: epub
Tags: MED010000, Medical/Cardiology, HEA039080, Health & Fitness/Diseases & Conditions/Heart
Publisher: Columbia University Press
Published: 2023-04-04T00:00:00+00:00

Chapter Twenty-Three

What Is Blood Pressure?

My doctors told me this morning my blood pressure is down so low that I can start reading the newspapers.

Ronald Reagan

Samuel Siegfried Karl Ritter von Basch, an Austrian-Jewish physician, best known as the personal physician of Emperor Maximillian of Mexico, invented the sphygmomanometer in 1891—yes, that is what your blood pressure monitor is called.1 Sphygmos comes from Greek for “pulse,” manos from Greek for “thin” or “rare,” and metron from Greek for “measuring.”

Blood pressure is the pressure that blood exerts on the inside of arteries throughout the body. When the heart beats, it creates pressure to push blood through the arterial tree to get oxygenated blood to every cell in the body (except the cornea). When the heart is relaxed between beats, the pressure produced by the blood in the arteries is the diastolic (from the Greek “to separate”) pressure. When the heart is pumping, the pressure exerted is the systolic (from the Greek “to pull together”) pressure. Blood will squirt thirty feet up into the air from the pressure created by a heartbeat.

Normal blood pressure in humans is less than 120 mmHg systolic over less than 80 mmHg diastolic; that is 120/80. Your dog’s blood pressure should be around 130/75; your cat 130/80. Mice come in at 120/70; a horse at 110/70; and an elephant at 180/120. The mammal with the highest normal blood pressure—due to a distance of six feet between their heart and brain—is the giraffe at 280/180.

Nearly half of adults in the United States (and one in four worldwide) have high blood pressure or “hypertension.”2 High blood pressure—often referred to as the silent killer because the first sign can be a life-ending stroke or heart attack—is when these pressures (systolic and diastolic) are consistently elevated above a healthy pressure of 120/80. Causes of high blood pressure include genetics (thanks to mom or dad), age, obesity, smoking, alcohol, salt, physical inactivity, diabetes, and kidney disease.

Over time the resulting force and friction of elevated pressures on the inner lining of the arteries causes damage. Cholesterol creeps into the damaged artery wall, creating atherosclerotic plaques. The long-term results of untreated high blood pressure are heart attack or heart failure, stroke, kidney failure, peripheral artery disease, and sexual dysfunction.

The results of high blood pressure were recognized in ancient times. Ancient Egyptian, Chinese, and Indian medical texts described patients with a “hard and bounding pulse.” These patients did not survive long. Recommended treatments included bloodletting or bleeding by leeches to lower the tension.

Franklin Delano Roosevelt (FDR) is a classic case study in everything that can go wrong with untreated hypertension.3 At the beginning of his presidency in 1933, FDR already had mild hypertension by today’s guideline recommendations, around 140/90 mmHg. By 1944, his blood pressures were over 200/120 mmHg, and he was manifesting heart failure symptoms. At the Yalta conference, with blood pressures of 250/150 mmHg, FDR was audibly wheezing and unable to complete sentences in radio addresses, suggesting severe heart failure. Some historians believe that Stalin took advantage of a debilitated president, determining the fate of Eastern Europe.

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