While it has long been known that a high resting heart rate can be a signal of poor general fitness, a recent study suggests that a higher heart rate while at rest may also be related to a increased risk of premature cardiovascular death. Researchers in Norway tracked almost 30,000 subjects, measuring their resting heart rates both at the start of the study and then again about 10 years later. After 12 years of follow-up, just over 10 percent of the group had died. Researchers analyzed changes in heart rate between the two assessments and correlated these with mortality; the results were published in the Journal of the American Medical Association.
Overall, an increase in resting heart rate signaled a higher risk of cardiovascular mortality. Those patients whose resting heart rates rose from under 70 beats per minute to over 85 during the study period had a 90 percent increased risk of death from heart disease than those patients whose resting heart rates remained steady at under 70. And patients who had resting heart rates between 70 and 85 beats per minute at the start, but whose rates increased to over 85, had an 80 percent higher risk of dying from heart disease.
The good news from this study is that the results suggest that certain patients were able to lower their risk of death from heart disease by lowering their resting heart rates. Those who had heart rates between 70 and 85 beats per minute initially, but whose rates decreased to under 70, had a 40 percent lower risk.
Many factors influence resting heart rate, such as genetics, age, diet, smoking, and physical activity level. But this study suggests that following measures that increase fitness, especially cardiac fitness, as measured by resting heart rate, may help reduce cardiovascular mortality. Based on this study, says ACSH's Dr. Gilbert Ross, we just have more evidence to recommend the usual healthy changes in a person s lifestyle including exercise, maintaining a healthy weight, and not smoking. And he points out that a resting heart rate above 85 beats per minute is almost always a problematic sign such individuals should consult with a physician.
