As a predictor of death, an abnormally low value for heart-rate recovery had a sensitivity of 56 percent, a specificity of 77 percent, a positive predictive value of 19 percent, and a negative predictive value of 95 percent. When the value for the 10th percentile (a decrease of eight beats per minute) was used as a cutoff, the sensitivity was 33 percent, the specificity 90 percent, the positive predictive value 24 percent, and the negative predictive value 90 percent; the relative risk was 4.1 (95 percent confidence interval, 3.0 to 5.4; P
Exercise testing of most of the patients was conducted according to the standard and modified Bruce protocols. Whether cardioactive medications were used on the day of the test was left to the discretion of the referring physician. So that workload could be more accurately estimated, the patients were not allowed to lean on the handrails. Midway through each stage of exercise, at peak exercise, and one minute after the cessation of exercise, data on symptoms, heart rate and rhythm, blood pressure (as measured by indirect arm-cuff sphygmomanometry), and estimated workload (as determined on the basis of standard tables) in metabolic equivalents (MET; 1 MET equals 3.5 ml of oxygen uptake per kilogram of body weight per minute) were collected and entered into a computer data base. The patients were encouraged to reach symptom-limited maximal exercise; the achievement of the target heart rate (based on age) alone was not a sufficient reason for the termination of testing. Chronotropic response during exercise was defined as the percentage of the heart-rate reserve (the difference between the maximal achievable heart rate [220 beats per minute minus age in years] and the resting heart rate) used at peak exercise. A failure to use 80 percent of the heart-rate reserve was considered to be evidence of an impaired chronotropic response. This measure is an independent predictor of mortality.
How does exercise affect breathing rate
After achieving peak workload, all the patients spent at least two minutes in a cool-down period during treadmill testing at a speed of 2.4 km (1.5 mi) per hour and a grade of 2.5 percent. This period was considered the recovery period. The value for the recovery of heart rate was defined as the reduction in the heart rate from the rate at peak exercise to the rate one minute after the cessation of exercise.
Exercise intensity: How to measure it - Mayo Clinic
A delayed decrease in the heart rate during the first minute after graded exercise, which may be a reflection of decreased vagal activity, is a powerful predictor of overall mortality, independent of workload, the presence or absence of myocardial perfusion defects, and changes in heart rate during exercise.
10 Factors That Affect Your Pulse & Heart Rate | …
The base-line characteristics of the patients according to whether their heart-rate recovery was normal or abnormal are summarized in . As compared with the patients with a normal value for heart-rate recovery, those with an abnormal value (≤12 beats per minute) were older, had higher resting heart rates, were more likely to have hypertension or diabetes, were more likely to smoke, and were more likely to have Q waves on the electrocardiogram or a history of coronary artery disease. They were also more likely to take nondihydropyridine calcium-channel blockers or vasodilators. There were no marked differences between the groups in the use of beta-blockers.
10 Factors That Affect Your Pulse & Heart Rate
There were 213 deaths from all causes. A total of 639 patients (26 percent) had abnormal values for heart-rate recovery. In univariate analyses, a low value for the recovery of heart rate was strongly predictive of death (relative risk, 4.0; 95 percent confidence interval, 3.0 to 5.2; P
Blood Pressure vs. Heart Rate (Pulse)
During exercise, the patients with an abnormal value for heart-rate recovery, as compared with those with a normal value, had lower increases in heart rate from base line (an increase of 61±21 beats per minute vs. an increase of 81±20 beats per minute, P