Determination of anaerobic threshold for assessment of functional state in patients with chronic heart failure.

Abstract

The use of anaerobic threshold in assessment of aerobic capacity was evaluated in 34 normal subjects and 47 patients with various kinds of chronic heart disease. Anaerobic threshold was determined as the oxygen consumption (W02) at which a linear relationship between pulmonary ventilation (yE) and V02 was lost during progressive treadmill exercise. Anaerobic threshold determined in this manner was validated with that determined by blood lactate measurements in eight normal subjects and nine cardiac patients (r = .962, p < .001). Thereafter, anaerobic threshold was determined only by respiratory measurements. In symptom-limited, maximal exercise, anaerobic threshold was reached well before maximal effort and corresponded to 70% of maximal V02 both in normal subjects and cardiac patients. Anaerobic threshold decreased as age progressed in normal subjects (r = -.70, p < .001). Anaerobic threshold in cardiac patients was lower than that in the normal subjects and decreased progressively as New York Heart Association functional classification advanced (normal, 32

Exercise testing in pulmonary arterial hypertension and in chronic heart failure

“…In the present patients, the anaerobic threshold occurred at a higher percentage of peak V9O 2 than in normal subjects. This has been previously noted in PPH [4], CHF [19] and older patients with various diseases associated with a decrease in peak V9O 2 [20]. It may be explained by the slower rise in V9O 2 above the anaerobic threshold and by the fact that resting V9O 2 already represents a considerable proportion of peak V9O 2 [4].…”

Detecting abnormalities in left ventricular function during exercise by respiratory measurement.

“…Many investigators have recently used the anaerobic threshold measurement to estimate the degree of cardiovascular impairment25-8 and effectiveness of therapy.22 '23 In general, the magnitude of the anaerobic threshold reduction has correlated well with the degree of hemodynamic abnormality. 5,7,8 Recent studies13-15 have suggested that the ejection fraction during exercise increases compared with rest in normal persons but does not change or decreases in patients with heart disease (particularly coronary artery disease). However, only a few investigators evaluated the change of the ejection fraction below and above the anaerobic threshold.…”

Reprodutibilidade da determinação do limiar anaeróbico em pacientes com insuficiência cardíaca

“…In HF patients, the validity of ventilatory methods is questioned, because of difficulties in detecting AT 1,6,12,14,26 in this population, and because of the inherent subjectivity of the visual analysis. 8 In a study conducted by Matsumara et al 16 , a highly reproducible AT detection was observed in a mixed population of healthy subjects and HF patients, by examining graphically the relationships between minute ventilation and VO 2 . The present study was conducted with a sample composed exclusively of individuals with HF, and the techniques of choice for AT detection were based on VCO 2 analysis 6,14,26 .…”

“…AT detection by ventilatory methods is considered valid 5,14,16,25 and in healthy subjects and athletes, it has proven to be highly reproducible 5,25 . In HF patients, the validity of ventilatory methods is questioned, because of difficulties in detecting AT 1,6,12,14,26 in this population, and because of the inherent subjectivity of the visual analysis.…”

“…15 Both VO 2peak and AT determined by the ventilatory method are considered valid and reproducible in healthy subjects 1,5,14,16 . However, as the determination of maximum stress can be subjective in individuals with HF 1,16 , AT can be an alternative option comparable to the VO 2peak to predict aerobic performance 1,8,13,[16][17][18] . Moreover, AT may be useful in determining the intensity of the training prescription in rehabilitation programs, in evaluating the effects of training, and in assessing the prognosis of patients with HF 4,8 .…”