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CLEVELAND, OHIO. The speed with which the pulse rate returns to
normal (heart rate recovery) after strenuous exercise is an
important indicator of heart health. Researchers at the Cleveland
Clinic Foundation now report that they have found a direct link
between heart rate recovery and the risk of premature death from
all causes and from cardiovascular disease in particular. Their study involved 5234 adults without evidence of cardiovascular disease who were enrolled in the Lipid Research Clinics Prevalence Study. The participants were all given a treadmill exercise test where they exercised until they attained 85 to 90 per cent of their age and fitness-predicted maximum heart rate for one minute or until there were medical contraindications to further exercise. The participants' peak heart rate and the rate two minutes after cessation of the exercise were both measured and heart rate recovery calculated as the peak rate minus the rate after two minutes. The median heart rate recovery was 49 beats/min and an abnormal heart rate recovery of 42 beats/min or less was seen in 1715 participants (33 per cent).
During the next 12 years 312 of the study participants died (6.2
per cent). The mortality among the participants with abnormal
heart rate recovery was 10 per cent compared to 4 per cent among
the ones with normal recovery giving an excess risk of 158 per
cent. This excess risk was reduced to 55 per cent when adjusting
for numerous other relevant risk factors. The excess risk among
those of the participants who died from cardiovascular disease was
over 200 per cent with 4 per cent dying in the group with abnormal
heart rate recovery versus 1 per cent in the group with normal
recovery. The researchers conclude that an abnormal heart rate
recovery after submaximal exercise is a powerful predictor of
premature death.
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