A percutaneous, servo-regulated, veno-arterial cardiopulmonary support system will be evaluated in anesthetized adult sheep. Maximum bypass flow will be determined as a function of venous uptake cannula type, vascular site (iliac vein, inferior vena cava, right atrium) and during pulsatile and non-pulsatile arterial return. Study conditions will include the normal beating heart, the depressed beating heart and the fibrillating heart. A coronary artery perfusion catheter and pump will be evaluated simultaneously. A compact, temporary, servo-cardiopulmonary support system would have application in the interventional cardiology support system would have application in the interventional cardiology laboratory, for cardiogenic shock and for patients requiring temporary support prior to or after cardiac surgery.