Cardiopulmonary Exercise Test: Fundamentals, Applicability and Interpretation

Abstract

Cardiopulmonary exercise test (CPET) has been gaining importance as a method of functional assessment in Brazil and worldwide. In its most frequent applications, CPET consists in applying a gradually increasing intensity exercise until exhaustion or until the appearance of limiting symptoms and/or signs. The following parameters are measured: ventilation; oxygen consumption (VO2); carbon dioxide production (VCO2); and the other variables of conventional exercise testing. In addition, in specific situations, pulse oximetry and flow-volume loops during and after exertion are measured. The CPET provides joint data analysis that allows complete assessment of the cardiovascular, respiratory, muscular and metabolic systems during exertion, being considered gold standard for cardiorespiratory functional assessment.1-6The CPET allows defining mechanisms related to low functional capacity that can cause symptoms, such as dyspnea, and correlate them with changes in the cardiovascular, pulmonary and skeletal muscle systems. Furthermore, it can be used to provide the prognostic assessment of patients with heart or lung diseases, and in the preoperative period, in addition to aiding in a more careful exercise prescription to healthy subjects, athletes and patients with heart or lung diseases.Similarly to CPET clinical use, its research also increases, with the publication of several scientific contributions from Brazilian researchers in high-impact journals.Therefore, this study aimed at providing a comprehensive review on the applicability of CPET to different clinical situations, in addition to serving as a practical guide for the interpretation of that test.

Reproducibility and Validity of the 6-Minute Stationary Walk Test Associated With Virtual Reality in Subjects With COPD

“…3 Similarly, a high correlation of 0.78 between maximum V O 2 in the cardiopulmonary exercise test and the 6MWD has been reported in the literature, as well as a correlation of 0.85 between the 6MWD and the V O 2 peak in the 6MWT. [39][40][41] Because the V O 2 peak values were highly correlated between the tests, this variable was selected as the main one to confirm validity, as has been done in other studies. 42 Thus, STVR-6 is a functional capacity assessment test and may be an alternative to the 6MWT, considering some negative aspects of the 6MWT, such as the physical space needed.…”

Lung ventilation impairment in asthma patients with obesity

“…Given the fact that carbon dioxide easily dissolves in blood and penetrates biological membranes, the value of РЕТСО 2 in the ideal pulmonary diffusing capacity should correspond to the partial pressure of carbon dioxide in arterial blood [13]. Although the level of РЕТСО 2 in the examined patients 4.8 ± 0.1 kPa did not exceed the normal values for this indicator (4.0-5.7 kPa) [14], but it was significantly higher than that in patients without obesity -4.3 ± 0.1 kPa, P < 0.05, indicating the compromised processes of pulmonary ventilation with a tendency to accumulate carbon dioxide in these patients.…”

Early Cardiac Rehabilitation Improved Prognosis in Patients with Heart Failure Following Acute Myocardial Infarction

“…The cardiovascular impairment has a direct negative effect on other systems and organs, including the respiratory, renal and neuromuscular systems. CPX is de ned as "gold standard" for the CRF of patients with cardiovascular disease, the clinical diagnosis assessment and prognosis prediction can be achieved from direct measurement of VO 2 , VCO 2 and VE [29] . The characteristic of CPX data in patients with CHF are: decreased VO 2 at VT < 40% of the predicted VO 2 max, O 2 pulse < 85% and as a plateau, increased VE/VCO 2 , wide breathing reserve and usually normal O 2 saturation [29,30] .…”

“…CPX is de ned as "gold standard" for the CRF of patients with cardiovascular disease, the clinical diagnosis assessment and prognosis prediction can be achieved from direct measurement of VO 2 , VCO 2 and VE [29] . The characteristic of CPX data in patients with CHF are: decreased VO 2 at VT < 40% of the predicted VO 2 max, O 2 pulse < 85% and as a plateau, increased VE/VCO 2 , wide breathing reserve and usually normal O 2 saturation [29,30] . Weber et al rst published a classi cation for peak VO 2 results: class A, VO 2 > 20 ml/kg/min; class B, VO 2 16-20 ml/kg/min; class C, VO 2 10-15 ml/kg/min; and class D, VO 2 < 10 ml/kg/min [31] .…”

“…For patients under medical treatment, a peak VO 2 < 10.0 ml/kg/min and a VE/VCO 2 slope ≧ 45 exist at the same time would indicate a very poor prognosis over the following 4-year [11] . It should be noted that, in order to achieve the prediction accuracy of peak VO 2 value on CHF, maximal exercise (at least RER > 1.05) should be achieved during the test [29] . Others evaluating the long term prognosis by VE/VCO 2 slope in CHF, and reported that it was an excellent independent value, even better than peak VO 2 , and could be achieved only from sub-maximal exercise [35,36] .…”