Figure 2.

Explicative example of different kinetics of the exercise-induced heart rate (HR) response between a heart failure patient (male, 55 years old) on sinus rhythm (black line) and another patient (male, 51 years old) with atrial fibrillation (red line). In spite of a significantly lower peak oxygen uptake (VO₂ peak), the atrial fibrillation patient shows an oxygen uptake at anaerobic threshold (AT) similar to the sinus rhythm patient. Modified from Magri et al.⁴⁰