A method of estimating an amount of work available to be performed by a blood pump implanted in a patient includes calculating a first coordinate value characterizing a volume of blood impelled in the pump and a second coordinate value characterizing a differential pressure across the pump for each of a plurality of flow rate data points of a given cardiac cycle of the patient, each flow rate data point indicative of a flow rate of blood through the pump. An area enclosed by the first and second coordinate values of the plurality of flow rate data points is determined, the determined area being indicative of an amount of work available to be performed by the blood pump.
