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.