Hemodynamic and thermal responses to a 30-minute constant-workload aerobic exercise in middle- or old-aged patients with cardiovascular diseases

Cardiovascular responses to walking in patients with peripheral artery disease

PURPOSES

The study's purposes were to assess the cardiovascular responses during constant-load walking and to identify predictors of this response in peripheral artery disease (PAD) patients.

METHODS

Seventy-nine patients with PAD performed a constant-load treadmill test (2 mph, 0% grade). During the test, systolic blood pressure (BP), diastolic BP, and HR were obtained at the fourth minute to the last minute of exercise. Patients were also characterized by demographic measures, cardiovascular risk factors, baseline exercise performance, and vascular measures.

RESULTS

During constant-load walking, there was a significant increase (P < 0.01) in systolic BP (+12 ± 10 mm Hg), diastolic BP (+6 ± 9 mm Hg), and HR (+5 ± 5 bpm). The HR responses were negatively correlated with the ischemic window (r = -0.23, P < 0.05), expressed as an area under the curve of the resting ankle systolic BP and its recovery from a maximal graded treadmill test, and positively correlated with the HR during the first minute of recovery from the maximal graded treadmill test (r = 0.27, P < 0.05). The increase in cardiovascular variables during constant-load walking was greater in subjects with a higher body mass index and in men (P < 0.05).

CONCLUSIONS

Patients with PAD had an increased cardiovascular response during constant-load walking, and these responses were greater in obese patients and in men. The clinical implication is that PAD patients engaged in walking training programs, particularly men and those with obesity, require frequent assessment of cardiovascular parameters to avoid exaggerated increases in BP and HR during constant-load walking.

Using the oxygen-cost diagram in ramp-slope selection for dyspneic patients

BACKGROUND

Maximal incremental exercise testing should be completed within 8-12 minutes. The ramp-slope influences the exercise duration. Oxygen-cost diagram (OCD) is a scoring scale for the capability of daily activity performed and therefore can be used to estimate the ramp-slope.

METHODS

The OCD-algorithm and the reported-algorithm were used prospectively in random order for selecting optimal ramp-slope: Ramp-slope(OCD)=Score(OCD)xweight in kg/40 for men and weight/50 for women and Ramp-slope(reported)=(Predicted V(O2peak)-V(O2unloaded))/100. Fifty-three dyspneic patients and 16 normal controls were enrolled to perform a ramp-pattern exercise. Fourteen patients not reaching maximum exercise levels were excluded. The exercise capacity, exercise time, and success rate of loaded exercise between 8 and 12 minutes were measured.

RESULTS

Comparing the reported-algorithm to the OCD-algorithm in normal controls, the only difference was that the ramp-slope was higher in males; in patients, the ramp-slope was higher in males, the exercise time shorter and the success rate lower (8.6+/-3.3 vs. 9.4+/-2.1 min, 61.5% vs. 84.6%, both p<0.05); in obese patients, the ramp-slope was lower and the exercise time longer.

CONCLUSION

OCD score can predict the ramp-slope selection for exercise testing in normal controls and dyspneic patients. This may be affected by gender and body weight when using the reported-algorithm for dyspneic patients.