An automated method for discriminating the cardiac beat, on the basis of a blood pressure sampled signal, having a starting point Pstart, operating according to a finite state machine for determining at least the diastolic point Pdia, the systolic point Psys, and the dicrotic point Pdic of the pressure signal, the method being apt to iteratively repeat on subsequent sections of the pressure signal; and instruments necessary to perform the automated method and the apparatus performing the same.