Abstract: Disclosed is a conduit that is adapted to be positioned in the myocardium to provide a passage for blood to flow from a heart chamber to a coronary artery. The conduit has a sphincter to open or close the passage in response to an electric current applied from a control unit and a one-way valve positioned therein to prevent the backflow of blood from the coronary artery into the heart chamber. Also disclosed is an implantable system or device comprising the conduit, a sensor unit to measure at least one physiological condition and a control unit to analyze signals form the sensor unit and open the sphincter for improving coronary blood flow in order to increase myocardial oxygen delivery during periods of high myocardial demand.