Akihiko Tajima

Heart rate and blood pressure response to ramp exercise and exercise capacity in relation to age, gender, and mode of exercise in a healthy population.

BACKGROUND The responses of heart rate (HR) and blood pressure to the ramp exercise test are not known and the current understanding of peak oxygen uptake and anaerobic threshold (AT) values in the normal Japanese population is insufficient. METHODS AND RESULTS A total of 749 healthy Japanese subjects aged 20-78 years underwent a cardiopulmonary exercise test using a cycle ergometer or treadmill ergometer with ramp protocols. HR, systolic blood pressure (SBP), and oxygen uptake VO2 at rest, at AT, and at peak exercise were determined. HR and SBP at peak exercise in a cycle ergometer and treadmill ergometer test decreased with age. Work rate at peak exercise in a cycle ergometer increased with body weight and decreased with age. VO2 at AT and at peak exercise were higher in treadmill ergometer testing than in cycle ergometer testing, and were not affected by exercise protocol. Both of these decreased with age. CONCLUSIONS The normal responses of HR and SBP to ramp exercise testing are reported for the first time. AT, peak VO2, and VO2 at each stage are shown for a healthy population. Some of these parameters were influenced by weight, gender, and age, as well as mode of exercise and the protocol used. These results provide useful reference values for interpreting the results of cardiopulmonary exercise testing.

Determination of the VE/VCO2 Slope from a Constant Work-Rate Exercise Test in Cardiac Patients

Incremental exercise testing to a symptom-limited maximum has been used to measure the ratio of the increase in ventilation (V.E) to the increase in CO(2) output (V.CO(2)) during exercise (V.E/V.CO(2) slope), a valuable index reflecting the severity of the ventilation-perfusion mismatch in heart failure. Here we studied whether this same value for the slope of V.E/V.CO(2) could be determined from a short constant work-rate exercise test of moderate intensity. Twenty-three patients with a previous myocardial infarction underwent moderate-intensity (69+/-15 W) constant work-rate exercise for 6 min and an incremental work-rate exercise test to the max. The V.E/V.CO(2) slope was calculated from the incremental exercise test from the start of increasing the work-rate to the ventilatory compensation point. The V.E/V.CO(2) slope was similarly calculated from the start of constant work-rate exercise until the 4th minute, when V.E and V.CO(2) changed minimally. The V.E/V.CO(2) slope determined from incremental exercise was 33.8+/-5.9, ranging from 20.9 to 42.8. The slope obtained from constant work-rate exercise was 32.9+/-5.7. The V.E/V.CO(2) slopes obtained from the two exercise tests did not differ significantly. The slope obtained from constant work-rate exercise was significantly positively correlated with the slope obtained from the incremental exercise (r=0.84, p<0.0001). The V.E/V.CO(2) slope can be determined from constant work-rate exercise at a moderate intensity. This indicates that the relationship between ventilation and CO(2) output is consistent and independent of the mode of exercise testing.