Explain the concept of fractional flow reserve (FFR) and its application in determining the need for coronary intervention.

Fractional Flow Reserve (FFR) is a physiological index used in cardiology to assess the severity of coronary artery stenosis (narrowing) and to guide the decision-making process for whether a coronary intervention, such as angioplasty or stent placement, is necessary. FFR helps to determine whether a specific blockage is causing a significant reduction in blood flow to the heart muscle. This approach aims to ensure that interventions are performed only when they are likely to result in meaningful improvements in blood flow and overall cardiac function. Explanation of Fractional Flow Reserve (FFR): FFR is a measurement of the pressure drop across a coronary artery stenosis during maximum blood flow demand, typically induced by pharmacological stress (such as adenosine infusion). It is calculated as the ratio of the mean distal coronary pressure (Pd) to the mean aortic pressure (Pa) during maximal hyperemia: FFR = Pd / Pa Application of FFR in Determining Coronary Inte....