What You Know About Blood Pressure May Be Wrong

Blood pressure measurement is a routine part of nearly every medical examination. Hypertension is one of the biggest cardiovascular risk factors for heart disease, stroke and death. Around 85 million people in the United States have it, which may show no symptoms and go undetected until it is too late. While blood pressure varies throughout the day, a reading of 180 over 110 mmHG or higher could be a sign of hypertensive crisis.


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The most common method for measuring blood pressure around the world is the “brachial cuff method,” which was invented over a century ago. Before 1855, physicians had to puncture an artery and calculated the pressure if the flowing blood using a mercury sphygmomanometer. The first non-invasive technique was invented by Samuel Siegfried Karl Ritter von Basch around 1881, when he came up with the idea to use water, and later air, to restrict blood flow through the arm.  It was further refined by Scipione Riva-Rocci who published “Un nuovo sfigmomanometro” in 1896, which re-incorporated the mercury manometer to von Basch’s technique. Finally, Russian surgeon Nikolai Korotkov added the stethoscope in 1905. The same general technique is used today, either manually or with a digital cuff.

However, recent research published in the Journal of American College of Cardiology has found that the cuff method may not accurately measure blood pressure in the mid-range. This study included over 2,500 participants and compared cuff blood pressure measurements with an invasive blood pressure measurement. The authors found that pressure at the aorta varied as much as 25mmHg from the pressure at the arm, which could push the patient over into the hypertension category and therefore impact clinical decisions. The researchers also found that the cuff method tends to overestimate the diastolic blood pressure at the brachial and aortic level, but underestimates systolic blood pressure at the brachial level.


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Until a more accurate, non-invasive method can be devised, the authors urged that best-practice for clinicians is to keep a record of repeated measurements over time for any at-risk patients.

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Laurie Breen

Laurie Breen is a freelance writer well-versed in research communications and grant writing. She received her Bachelors Degree in Psychology from Smith College and has worked previously at the University of Queensland's Centre for Clinical Research in Brisbane, Australia. Her favorite conversational topic is "antibiotic-resistant bacteria," making her a big hit at parties.