A dual-balloon cardiac pump comprises a flexible catheter tube in pneumatic communication with inflatable ventricular and aortic balloons, which are inflated and deflated in accordance with a programmed sequence of pressurized inert gas into the catheter tube as regulated by a control unit. The programmed sequence rapidly inflates and deflates the ventricular balloon after left ventricular contraction is completed. The programmed sequence inflates the aortic balloon after the aortic valve closes and deflates it just before the next systolic cycle begins.