To print: Select File and then Print from your browser's menu --------------------------------------------------------------------------------------- Title: Slow Heart Rate Recovery Linked To Higher Mortality Risk URL: http://www.pslgroup.com/dg/13F7D6.htm Doctor's Guide October 28, 1999
CLEVELAND, OH -- October 28, 1999 -- A simple and often overlooked measurement taken during routine exercise testing is a powerful predictor of mortality, even more powerful than expensive, nuclear-based imaging tests, cardiologists at the Cleveland Clinic have found. That was the key finding of a study published in the Oct. 28 issue of the New England Journal of Medicine.
Physicians routinely obtain the measurement, known as "heart rate recovery," during exercise testing. "One simply subtracts the heart rate one minute after a patient finishes exercising from the heart rate at peak exercise," said Dr. Michael S. Lauer, director of the Cleveland Clinic exercise laboratory and the senior investigator of the study.
The investigators looked at 2,428 adults who had undergone standard exercise testing as part of their clinical care at the Cleveland Clinic. Patients' heart rates were measured before, during, and one minute after exercise, and the patients themselves were followed for six years to see how many died in the interim.
"In most cases, heart rate falls about 15 to 25 beats per minute after a person exercises to exhaustion and then stops," said Dr. Lauer. "But we found that 25 percent of patients in the study had a heart recovery rate of less than 12 beats per minute. That is, their heart rate had failed to fall by at least 12 beats per minute during the first minute after exercise. Of these patients, 19 percent died during the six-year follow-up. In contrast, among those who had a normal heart rate recovery, only 5 percent died, a death rate of less than 1 percent per year."
Dr. Lauer called heart rate recovery "an extraordinarily powerful predictor of risk." In fact, it proved to be a more reliable predictor of mortality than blood flow abnormalities noted on nuclear scans and electrocardiographic changes (a prime focus of most physicians). It was also equally as powerful as overall physical fitness.
Physicians often send patients for exercise testing to predict the risk of heart attacks and death. Those deemed to be at high risk may then be sent for more aggressive therapies, such as bypass surgery of angioplasty, or may be placed on a regimen of powerful medications. "The value of a simple measure like heart rate recovery is that doctors can quickly and easily identify people who are at low risk for these problems," Dr. Lauer said. "It makes no sense to send a patient for potentially risky procedures when you already know that their risk for dying is less than 1 percent per year."
There remains a number of unanswered questions related to this research, such as why heart rate recovery is such a powerful predictor of death and what can be done to reduce these patients' risk of dying. "We believe this finding reflects intrinsic abnormalities of the nervous system, which we already know are tied to death risk, though the precise mechanisms are not well known," said Dr. Lauer. He suggested that possible remedies for abnormal heart rate recovery might include exercise training, smoking cessation, and certain types of drugs such as beta-blockers. Still, he said, "much research will be needed."
The Cleveland Clinic Foundation, founded in 1921, integrates clinical and hospital care with research and education in a private, non-profit group practice. At the Cleveland Clinic and Cleveland Clinic Florida in 1998, nearly 1,000 full-time salaried physicians representing more than 100 medical specialities and subspecialties provided for 1,735,484 outpatient visits and 49,893 hospital admissions for patients from throughout the United States and more than 80 countries. In 1997, The Cleveland Clinic Health System was formed. It now comprises The Cleveland Clinic Foundation, Euclid, Fairview, Hillcrest, Huron, Lakewood, Lutheran, Marymount and South Pointe hospitals, and the Cleveland Clinic Children's Hospital for Rehabilitation. With 3,010 staffed beds, the Cleveland Clinic Health System offers broad geographic coverage, a full continuum of care, improved quality and lower cost of care to Northeast Ohio residents. --------------------------------------------------------------------------------------------- Copyright © 1999 P\S\L Consulting Group Inc. All rights reserved. Republication or redistribution of P\S\L content is expressly prohibited without the prior written consent of P\S\L. P\S\L shall not be liable for any errors, omissions or delays in this content or any other content on its sites, newsletters or other publications, nor for any decisions or actions taken in reliance on such content. --------------------------------------------------------------------------------------------- This news story was printed from *Doctor's Guide to the Internet* located at http://www.docguide.com --------------------------------------------------------------------------------------- Return to News Story Page This site is maintained by webmaster@pslgroup.com Please contact us with any comments, problems or bugs. All contents Copyright (c) 1998 P\S\L Consulting Group Inc. All rights reserved.