[Reproducibility of the determination of anaerobic threshold in patients with heart failure].
BACKGROUND
The anaerobic threshold (AT) provides information on functional capacity in heart failure (HF). However, the visual determination of the AT by ventilatory methods is subjective, being susceptible to differences between examiners.


OBJECTIVE
To evaluate the inter- and intra-examiner reproducibility in the determination of the AT in patients with mild to moderate HF, using visual-graphic and V-slope methods. To compare and correlate the results.


METHODS
After performing a cardiopulmonary exercise test on a treadmill, visual-graphic and V-slope methods were used for the analysis of the AT. To assess the reproducibility, three examiners determined the AT twice by each method, on different days. For statistical analysis, we used intra-class correlation coefficient (ICC) with p <0.05.


RESULTS
We evaluated a total of 16 subjects, with a mean age of 45.9 +/- 9.7 years, left ventricle ejection fraction of 20.5 +/- 8.1%, and peak exercise oxygen consumption of 20.6 +/- 7.8 mL/kgmin-1. The intra-examiner reproducibility was high in both methods for the three examiners, with ICC values between 0.87 and 0.99. The inter-examiner reproducibility was moderate in both visual-graphic method (ICC = 0.69) and V-slope method (ICC = 0.64). When comparing methods, the ICC found was 0.91.


CONCLUSIONS
AT determination by visual-graphic and V-slope methods showed high and moderate inter- and intra-examiner reproducibility, respectively. Moreover, both methods showed good agreement when compared with each other. These results suggest that both methods can be used in a reproducible way in AT assessment of patients with mild to moderate HF.
Pereira
Danielle Aparecida Gomes
DA
Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil. d.fisio@ig.com.br
Vieira
Danielle Soares Rocha
DS
Samora
Giane Amorim Ribeiro
GA
Lopes
Fernanda Lima
FL
Alencar
Maria Clara Norman
MC
Lage
Susan Martins
SM
Parreira
Verônica Franco
VF
Velloso
Marcelo
M
Moreira
Maria da Consolação Vieira
Mda C
Britto
Raquel Rodrigues
RR
D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology*; D005080:Exercise Test / Q000379:methods* / Q000592:standards; D005260:Female; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010101:Oxygen Consumption / Q000502:physiology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012737:Sex Factors; D013997:Time Factors