1. A processing apparatus for processing cardiac data of a living being, the processing apparatus comprising: a fractional flow reserve providing unit, implemented by a computer, that provides a distribution of fractional flow reserve values being indicative of the fractional flow reserve of different coronary arteries of the living being, a myocardial perfusion providing unit, implemented by the computer, that provides a distribution of myocardial perfusion values being indicative of the myocardial perfusion of different portions of the myocardium of the living being, an assignments providing unit, implemented by the computer, that provides assignments between coronary arteries and portions of the myocardium of the living being, wherein the assignments define which portion of the myocardium is fed by which coronary artery, a correspondence determining unit, implemented by the computer, that determines degrees of correspondence between fractional flow reserve values and myocardial perfusion values based on the distribution of fractional flow reserve values, the distribution of myocardial perfusion values and the assignments between the coronary arteries and portions of the myocardium.