A method of estimating a heart rate of a patient having an implantable blood pump including, during operation of the blood pump continuously detecting a plurality of cardiac cycles, each of the plurality of cardiac cycles including a length； sorting the plurality of cardiac cycles according to the length； filtering the plurality of cardiac cycles between one of a group consisting of including a reliable condition and at least one unreliable condition； continuously estimating a heart rate according to the length of the plurality of cardiac cycles and the reliable condition； and if the at least one unreliable condition is detected, modifying the estimated heart rate based on information associated with the detected at least one unreliable condition.
