It is a technique that determines whether a stenosis (narrowing) of the artery should be treated with stent or not. A special catheter is inserted into the body following the coronary catheterization technique. Through this catheter will be introduced a very delicate special “wire” that will have two sensors: in in the middle and another few centimeters before the end of the wire. Sensors determine blood pressure before and after the stenosis. This allows the cardiologist to decide whether to implant a stent or not.