Résumé : Presently described is a method and system for dynamically determining a target flow rate of a pump of a system for providing veno-arterial extracorporeal membrane oxygenation, VA-ECMO, of a subject during a VA-ECMO session compriseng receiving multiple sets of measured parameters of the subject, wherein each set of the multiple sets of measured parameters comprises heart contractility indicator, and the multiple sets of measured parameters are received over time during the VA-ECMO session, determining, using the multiple sets of measured parameters, the target flow rate of the pump, wherein in response to a stable or increase in heart contractility indicator, the target flow rate is adjusted by a reduction, and in response to a decrease in heart contractility indicator, the target flow rate is adjusted by an increase. Also described is a device for interfacing to a VA-ECMO system, device is configured for carrying out the method.