Symptom-limited Cycle Exercise Test Research Articles

Intensity and quality of exertional dyspnoea in patients with stable pulmonary hypertension.

Dynamic hyperinflation is observed during exercise in 60% of patients with clinically stable pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH), intensifying exertional dyspnoea. The impact of dynamic changes in respiratory mechanics during exercise on qualitative dimensions of dyspnoea in these patients has not been evaluated.26 patients (PAH n=17; CTEPH n=9) performed an incremental symptom-limited cycle exercise test. Minute ventilation (V'E), breathing pattern, operating lung volumes and dyspnoea intensity were assessed throughout exercise. Dyspnoea quality was serially assessed during exercise using a three-item questionnaire (dyspnoea descriptors). The inflection point of tidal volume (V T) relative to V'E was determined for each incremental test. Changes in inspiratory capacity during exercise defined two groups of patients: hyperinflators (65%) and non-hyperinflators (35%). Multidimensional characterisation of dyspnoea was performed after exercise using the Multidimensional Dyspnea Profile.In hyperinflators, inspiratory capacity decreased progressively throughout exercise by 0.36 L, while remaining stable in non-hyperinflators. The "work/effort" descriptor was most frequently selected throughout exercise in both types of patients (65% of all responses). At the V T/V'E inflection, work/effort plateaued while "unsatisfied inspiration" descriptors became selected predominantly only in hyperinflators (77% of all responses). In the affective domain, the emotion most frequently associated with dyspnoea was anxiety.In pulmonary hypertension patients who develop hyperinflation during exercise, dyspnoea descriptors referring to unsatisfied inspiration become predominant following the V T/V'E inflection. As these descriptors are generally associated with more negative emotional experiences, delaying or preventing the V T/V'E inflection may have important implications for symptom management in patients with pulmonary hypertension.

Testosterone Attenuates Age-Related Fall in Aerobic Function in Mobility Limited Older Men With Low Testosterone.

Testosterone increases skeletal muscle mass and strength, but the effects of testosterone on aerobic performance in mobility-limited older men have not been evaluated. To determine the effects of testosterone supplementation on aerobic performance, assessed as peak oxygen uptake (V̇O2peak) and gas exchange lactate threshold (V̇O2θ), during symptom-limited incremental cycle ergometer exercise. Subgroup analysis of the Testosterone in Older Men with Mobility Limitations Trial. Exercise physiology laboratory in an academic medical center. Sixty-four mobility-limited men 65 years or older with low total (100-350 ng/dL) or free (<50 pg/dL) testosterone. Participants were randomized to receive 100-mg testosterone gel or placebo gel daily for 6 months. V̇O2peak and V̇O2θ from a symptom-limited cycle exercise test. Mean (SD) baseline V̇O2peak was 20.5 (4.3) and 19.9 (4.7) mL/kg/min for testosterone and placebo, respectively. V̇O2peak increased by 0.83 (2.4) mL/kg/min in testosterone but decreased by -0.89 (2.5) mL/kg/min in placebo (P = .035); between group difference in change in V̇O2peak was significant (P = .006). This 6-month reduction in placebo was greater than the expected -0.4-mL/kg/min/y rate of decline in the general population. V̇O2θ did not change significantly in testosterone but decreased by 1.1 (1.8) mL/kg/min in placebo, P = .011 for between-group comparisons. Hemoglobin increased by 1.0 ± 3.5 and 0.1 ± 0.8 g/dL in testosterone and placebo groups, respectively. Testosterone supplementation in mobility-limited older men increased hemoglobin and attenuated the age-related declines in V̇O2peak and V̇O2θ. Long-term intervention studies are needed to determine the durability of this effect.

Can an 86-year-old woman with advanced lung disease be a world class athlete?

We describe the case of an 86-year-old woman with advanced obstructive lung disease (forced expiratory volume in 1 s/forced vital capacity ratio (FEV(1)/FVC)=34%) who remains capable of superior athletic performance. Detailed pulmonary function testing was performed to characterize this patient's baseline respiratory impairment. An incremental symptom limited cycle exercise test was performed to characterize her sensory, ventilatory, cardiovascular and respiratory mechanical responses to exercise. Despite significant respiratory mechanical constraints, her peak cycle work rate and oxygen uptake were 177 and 175% predicted, respectively, and she achieved this while experiencing only moderate exertional dyspnea. She holds numerous world and national masters swim records despite her substantial objective respiratory impairment and continues to compete and set records to this day. We propose that lifelong participation in rigorous endurance training resulted in desensitization to dyspnea and has led to important cardiorespiratory adaptations that may have counterbalanced the known negative effects of obstructive lung disease on exercise performance and dyspnea.

Prognostic value of cycle exercise testing prior to and after outpatient cardiac rehabilitation

The prognostic value of cycle exercise testing prior to and after outpatient cardiac rehabilitation (OCR) is not well established. 2146 consecutive patients undergoing symptom-limited cycle exercise testing at OCR entry, of whom 1853 (86%) also had a test at end of OCR, were followed for a median of 33 months. All-cause and cardiovascular annual mortality rates were 1.2% and 0.8%, respectively. At OCR entry, older age, diabetes, lower left ventricular ejection fraction (LVEF), calcium channel blocker use, and lower workload [hazard ratio (HR) 2.38 if < or = 105 W; p<0.001] were independent predictors of death. Diabetes, diuretic use, and lower workload [HR 3.53 if < or = 105 W; p=0.001] were independently associated with cardiovascular death. At end of OCR, older age, lower LVEF, lower workload (HR 2.34 if <140 W; p=0.009), and lower increase in peak heart rate from entry to end of OCR (HR 2.46 if <4 bpm; p=0.002) were independently associated with all-cause mortality. Older age, lower LVEF, lower increase in systolic blood pressure (HR 2.97 if <54 mm Hg; p=0.02), and lower increase in peak heart from entry to end of OCR (HR 2.72 if <4 bpm; p=0.013) were independently associated with cardiovascular mortality. Failure to undergo a test at end of OCR was an additional independent predictor of all-cause (HR 2.51; p<0.001) and cardiovascular mortality (HR 2.56; p=0.003). Symptom-limited cycle exercise testing prior to and after OCR provides important prognostic information.

Mechanisms of dyspnoea relief and improved exercise endurance after furosemide inhalation in COPD

Background:This study examined the effects of inhaled furosemide on the ventilatory and perceptual response to high-intensity constant-load cycle exercise in chronic obstructive pulmonary disease (COPD).Methods:In a randomised, double-blind, placebo-controlled, crossover...

Maximal Workload and Oxygen Uptake during Exercise after Aortic-Valve Replacement

Context:It is more feasible to assess functional capacity with an exercise test than to measure peak-exercise VO2.Objective:To assess whether maximal workload reliably predicts peak VO2.Patients:Thirty-six patients after aortic-valve replacement during routine follow-up.Design:Incremental symptom-limited cycle exercise test in the upright position with increments of 20 W/min.Setting:Out-clinic patients, university hospital.Main Outcome Measures:Maximal workload, ventilatory threshold, and peak VO2.Results:Maximal workload was 151 ± 39 W, and peak VO2, 1649 ± 486 ml/min. The correlation coefficient between maximal workload and peak VO2 was r = .92 (P &lt; .0001). The regression equation for the estimation of peak VO2 was y = 11.7 (maximal workload in watts) – 110.7. Peak VO2 calculated with this equation was 1657 ± 451 ml/min.Conclusions:Maximal workload during ergometry in the upright position reliably predicted peak VO2.