In heart failure (HF), anaerobic threshold (AT) may be indeterminable but its value held a relevant prognostic role. AT is evaluated joining three methods: V-slope, ventilatory equivalent, and end-tidal methods. The possible non-concordance between the V-slope (met AT) and the other two methods (vent AT) has been highlighted in healthy individuals and named double threshold (DT).
Reference: The double anaerobic threshold in heart failure: MECKI score database overview. Rovai S, Zaffalon D, Cittar M, Felli LF, Salvioni E, Galotta A, Mattavelli I, Carriere C, Mapelli M, Merlo M, Vignati C, Sinagra G, Agostoni P. ESC Heart Fail. 2022 May 17.