fig1

Figure 1. Coronary physiology measurements in the cardiac catheterisation laboratory. FFR: Fractional flow reserve; iFR: instantaneous wave-free ratio; RFR: resting full-cycle ratio; dPR: diastolic pressure ratio; DFR: diastolic hyperaemia-free ratio; QFR: quantitative flow ratio; IMR: index of microcirculatory resistance; Rmicro: microvascular resistance (derived by continuous thermodilution); mMR: minimal microvascular resistance; hMR: hyperaemic microvascular resistance; Pzf: zero-flow pressure; RRR: resistive reserve ratio; IMRangio: angiography-derived index of microcirculatory resistance.