ABSTRACT

Cardiopulmonary exercise testing (CPX) is a noninvasive method for assessing physiological changes during physical exercise. Functional capacity has been evaluated using prediction equations. However, this evaluation method may yield different outcomes when applied to a healthy male population and patients with chronic heart failure (HF). This study aimed to compare the estimated and obtained values of oxygen consumption (VO₂) during CPX both at the ventilatory anaerobic threshold (VAT) and at peak exercise for healthy men and HF patients. For that, 56 men were divided into 3 groups: (1) 18 young and healthy (YG) (27±6.01 years); (2) 14 healthy older adults (OG) (61±6.3 years); and (3) 24 chronic HF patients (HFG) (53±13.6 years). CPX in cycle ergometer was administered to all individuals for determining VO₂ at the VAT and peak exercise. Then, VO₂ was estimated at the two moments using a prediction equation, and estimated values were compared to those obtained. Estimated VO₂ was significantly higher than obtained VO2 in OG (16.9±1.8 vs. 13.1±2.1mL/kg/min) and HFG (12±6.9 vs. 8.7±2.5mL/kg/min). We found no difference between estimated and obtained VO₂ for the YG (22,6±5,5 vs. 23,1±8,7mL/kg/min). The prediction equation overestimated VO₂ values for older adults and HF patients. However, the YG obtained similar values than those estimated.

Keywords:
Exercise Test; Oxygen Consumption; Heart Failure, Anaerobic Threshold