Measuring blood pressure is a routine part of healthcare check-ups, crucial for monitoring heart health. For years, the standard practice involved checking blood pressure in just one arm. However, new research is suggesting a more comprehensive approach: measuring blood pressure in both arms. This article delves into why taking blood pressure in both arms could be a more accurate way to identify hypertension and assess cardiovascular risk.
(Zbynek Pospisil/iStock via Getty Images) – A doctor accurately measures a patient’s blood pressure in both arms during a checkup.
The Case for Measuring Blood Pressure in Both Arms
A recent study published in the American Heart Association journal Hypertension has brought to light the importance of bilateral blood pressure measurement. The research indicates that taking readings from both arms and using the higher value provides a more precise picture of a person’s blood pressure status. This method is more effective in identifying individuals with hypertension and those at an elevated risk of cardiovascular disease and mortality compared to relying on a single arm measurement.
While current guidelines recommend using the higher reading from both arms, this practice hasn’t always been consistently followed, partly due to a lack of strong scientific evidence. This new study provides robust support for adopting the two-arm measurement approach as a standard procedure.
According to Dr. Christopher Clark, the lead author of the study and a clinical senior lecturer at the University of Exeter Medical School, “If you are only doing one arm, you can’t know which is the higher-reading arm. And if you don’t catch high blood pressure, you can’t treat it. We can now support the adoption of using the higher reading from both arms.” This highlights a critical point: missing a high blood pressure diagnosis can have serious implications for patient care.
Why Accurate Blood Pressure Readings are Crucial
Hypertension, or high blood pressure, affects nearly half of adults in the United States. It is defined as a systolic reading (the top number) of 130 mmHg or higher, or a diastolic reading (the bottom number) of 80 mmHg or higher. High blood pressure is a major risk factor for severe health conditions, including heart disease, heart attacks, and strokes.
The American Heart Association (AHA) had already recognized the importance of accurate blood pressure measurement. In their 2019 scientific statement on proper blood pressure measurement, the AHA recommended measuring blood pressure in both arms during an initial visit. They advised using the arm with the higher reading for all subsequent measurements. The statement also emphasized the importance of using the correct cuff size based on the patient’s arm circumference.
Study Findings: The Impact of Two-Arm Measurement
To investigate the significance of measuring blood pressure in both arms, researchers analyzed data from 53,172 adults across 23 different studies globally. The average age of the participants was 60 years.
The study revealed that using the lower arm reading instead of the higher arm reading led to a significant underestimation of hypertension. Specifically, 12% of individuals who were diagnosed with hypertension based on the higher arm reading would have been misclassified as having normal blood pressure if only the lower arm reading was considered. This misclassification could prevent them from receiving necessary treatment and lifestyle advice.
Furthermore, the researchers examined the impact of measurement methods on cardiovascular risk assessment. By using the higher arm reading, an additional 3.5% of participants (645 individuals) were reclassified as being at risk for cardiovascular disease based on the risk score developed by the AHA and American College of Cardiology. Using the Framingham risk score, another model for predicting heart disease risk, an even larger percentage, 4.6% (over 1,000 people), were additionally identified as being at risk for coronary heart disease. In both risk assessment models, utilizing the higher arm readings proved to be a better predictor of future cardiovascular events.
Expert Perspectives on Clinical Practice
The implications of this research are significant for clinical practice. According to the Centers for Disease Control and Prevention (CDC), high blood pressure was a primary or contributing factor in over 670,000 deaths in the U.S. in 2020. Globally, uncontrolled hypertension is a leading cause of premature death and cardiovascular events.
Dr. Shawna Nesbitt, a professor of internal medicine at UT Southwestern Medical Center specializing in blood pressure disorders, supports the study’s findings. She stated that measuring blood pressure in both arms, although slightly more time-consuming, is essential for obtaining more accurate readings. Dr. Nesbitt also stressed the importance of taking multiple measurements to ensure consistency and accuracy. Failing to do so could result in patients walking around with uncontrolled high blood pressure, increasing their long-term risk of heart attacks and strokes.
Practical Guidance for Blood Pressure Monitoring
For individuals who monitor their blood pressure at home using an ambulatory device, Dr. Clark advises attaching the monitor to the arm that consistently shows the higher reading. For those who self-monitor with a standard home blood pressure monitor, it is recommended to check blood pressure in both arms initially to determine which arm typically gives a higher reading. This arm should then be used for routine measurements.
Conclusion: Prioritizing Accuracy in Blood Pressure Measurement
In conclusion, the evidence strongly supports the practice of measuring blood pressure in both arms and using the higher reading for diagnosis and risk assessment. This approach leads to more accurate identification of hypertension and cardiovascular risk, ensuring that individuals receive appropriate medical attention and lifestyle guidance. While it may require a slight adjustment in clinical practice and home monitoring routines, the benefits of improved accuracy and potentially preventing serious health outcomes are substantial. Prioritizing accurate blood pressure measurement is a vital step in promoting better cardiovascular health for everyone.
