The fractional flow reserve FFR is used by interventional ca

The fractional flow reserve (FFR) is used by interventional cardiologists to decide if a stenting is required. It measures the ratio of the pressure distal to the stenosis (Pdist) to the pressure proximal to the stenosis (Pprox). If the ratio (Pdist/Pprox) is greater than 0.75 stenting is not required. Using your engineering knowledge, discuss the assumptions and limitations used in this technique. How does the pressure profile for an idealized coronary artery under steady flow change with significant stenosis.

Solution

Stenosis in general is the contraction of aortic valve. Blood flows from lower left chamber called as ventricle of heart into the aorta through aortic valve. As a result of stenosis the aortic valve is unable to open properly which in turns put pressure on heart, to work hard to pump the blood via a valve. This builds the pressure in the left ventricle of the heart and the muscles become thick. And in long run this leads to heart failure. This condition occurs due to the calcium building in the valve which makes it hard and thick and also due to congenital defect.

Symptoms include chest pain, feeling dizzy and short breath.