In children with severe advanced heart failure where medical management has failed, mechanical circulatory support in the form of veno-arterial extracorporeal membrane oxygenation (VA ECMO) or ventricular assist device represents life-sustaining therapy.The two primary forms of mechanical circulatory support are veno-arterial extracorporeal membrane oxygenation (VA ECMO) and ventricular assist devices (VAD). The two technologies have unique advantages and disadvantages and could be considered as complementary devices and, at times, used in sequence as the clinical scenario dictates.