Significance of anaerobic threshold in the assessment of functional state in patients with chronic heart disease
Matsumura, N.
Hokkaido Journal of Medical Science 64(1): 55-64
1989
ISSN/ISBN: 0367-6102 PMID: 2722127 Document Number: 336255
The value of anaerobic threshold measurement in the assessment of aerobic capacity was evaluated in 14 athletic and 62 normal subjects, as well as in 165 patients with chronic heart disease. Anaerobic threshold was defined as the oxygen consumption at which pulmonary ventilation began to increase non-linearly in relation to oxygen consumption during symptomatic maximal graded treadmill exercise. Anaerobic threshold was detectable in most of the cardiac patients as well as in athletic and normal subjects, and correlated well with individual lactate threshold. It was highly reproducible in subjects in whom measurements were repeated. Anaerobic threshold decreased as age progressed in normal subjects as well as other exercise parameters. In cardiac patients, anaerobic threshold was significantly lower than in athletic or normal subjects, and decreased progressively as New York Heart Association classification advanced. Anaerobic threshold correlated loosely with pulmonary wedge pressure and cardiac index in patients, and increased after successful cardiac surgery reflecting improved cardiac function. Thus, determination of anaerobic threshold by respiratory measurements is an accurate and objective method to assess aerobic capacity in cardiac patients as well as in athletic and normal subjects.