A few minutes of exercise may reveal a lot about a person’s risk of dying of heart disease.
Researchers at the University of Rochester Medical Center in Rochester, N.Y., found that heart disease patients who were slow to recover from walking on a treadmill were more likely to die of their disease in subsequent years.
The 757 patients in the study, most of whom were men, were all recovering from a heart attack or episodes of uncontrolled chest pain in the previous several months. They entered the study between 1988 and 1991.
The participants exercised on a treadmill until they reached their target heart rate — defined as 220 beats per minute minus their age in years — or experienced chest pain or fatigue. Their heart rate was measured again two minutes after exercise, and the difference between the target heart rate and this slower heart rate was called the “heart rate recovery.”
A total of 122 patients had another non-fatal heart attack or episode of uncontrolled chest pain, and 11 died of heart disease. Most of the patients who subsequently died of heart disease had been unable to achieve a normal peak exercise heart rate in their treadmill test. These patients also had a lower heart rate recovery than other participants.
The researchers suggested that a heart rate recovery of less than 26 beats per minute should alert doctors that heart disease patients have an increased risk of dying as a result of their cardiac problems.
Dr. Illena Antonetti, a study co-author and trainee in internal medicine, says the findings could be valuable because heart rate recovery is easy to measure. “Any physician in a primary care office can do this — put (a patient) on a treadmill, see what they’re heart rate does after two minutes,” she says. “We don’t have enough research to say ‘You’re going to die of this and this is the mechanism,’ but there’s enough there to encourage the patients to modify their lifestyle and have better followup to reduce their risk.”