Fractional Flow Reserve (FFR) 

Discussion on fractional flow reserve or FFR for guiding coronary percutaneous intervention and functional SYNTAX score.
Coronary angiography gives a visual impression about the severity of the stenosis. But it need not imply the actual functional significance of the stenosis in terms of flow physiology.
It is often difficult to decide which are the flow limiting lesions when there are multiple stenoses in same or different territories. It is here that the fractional flow reserve estimation helps.
FFR is estimated using a guide wire with a pressure transducer. FFR wires have properties similar to the floppy guide wires so that they can passed across coronary lesions back and forth easily to assess the pressure drop across the lesions.