WASHINGTON (March 27, 2014) The formula for peak exercise heart rate that doctors have used for decades in tests to diagnose heart conditions may be flawed because it does not account for differences between men and women, according to research to be presented at the American College of Cardiology's 63rd Annual Scientific Session.
The simple formula of "220 minus age" has been widely used to calculate the maximum number of heart beats per minute a person can achieve. Many people use it to derive their target heart rate during a workout. Doctors use it to determine how hard a patient should exercise during a common diagnostic test known as the exercise stress test.
After analyzing more than 25,000 stress tests, the researchers found significant differences between men and women and developed an updated formula to reflect those nuances.
"The standard that's currently in use is somewhat outdated," said Thomas Allison, M.D., cardiologist and director of stress testing at Mayo Clinic, and senior author of the study. "We want to make sure that when people do the stress test, they have an accurate expectation of what a normal peak heart rate is. Every so often, you need to recalibrate what's considered normal."
The new formula can help people better optimize their workouts and also improve the accuracy of test results. Stress tests, which are commonly used to help diagnose conditions such as coronary heart disease, heart valve disease and heart failure, require patients to exercise near their top capacity while technicians monitor the patient's cardiac performance.
The researchers drew data from 25,000 patients who took stress tests at Mayo Clinic between 1993 and 2006. The sample included men and women 40 to 89 years of age who had no history of cardiovascular disease.
The study reveals that although everybody's peak heart rate declines with age, the decline is more gradual in women. As a result, the previous
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American College of Cardiology