Figure 2

Dynamic ³¹P-MRS results in an HF patient. ³¹P-MRS results in an HF patient (a) Shows ³¹P MR spectra from a representative HF patient’s calf muscle pre-exercise, post-exercise, and at end-recovery. The dashed arrows indicate the distance between Pi and PCr peaks (b) shows the kinetics of PCr signal intensity during the three phases for the HF patient and (c) shows the PCr recovery time constant (k = 47.1 s for this patient) after fitting the phase III PCr recovery data.