Extracorporeal membrane oxygenation (ECMO) for adult post cardiotomy cardiogenic shock has had limited success. The efficacy of a heparin bonded ECMO system was tested in 11 patients (eight men, three women; mean age: 63 +/- 8 years), all of whom were in post cardiotomy shock refractory to inotropes and intra-aortic balloon pumping (IABP). The system consisted of a right atrial-to-aortic loop using a hollow fiber oxygenator driven by a vortex pump. All blood contact surfaces were heparin bonded. Mean duration of support was 47.9 hr (range: 22-92.5 hr). Mean prothrombin time, activated partial thromboplastin time, and activated clotting time during full support were 17 +/- 8, 57.5 +/- 38, and 152 +/- 59 sec, respectively. Mean transfusion requirements for packed red blood cells, fresh frozen plasma, and platelets were 24 +/- 9, 19 +/- 9, and 38 +/- 15 units, respectively. Complications included acute renal failure (1 patient), sepsis (3 patients), elevation of hepatic enzymes (7 patients), and myocardial infarction (11 patients). Oxygenator failure occurred in 4 patients, and 10 patients had plasma hemoglobin levels exceeding 30 mg/L. No patient experienced focal neurologic deficit. Eight (73%) patients were weaned from ECMO. Five (45.4%) of these are alive and have been discharged home with a mean follow-up of 317 +/- 76 days (range: 179-416 days). This heparin-free ECMO system allows rapid and simple deployment and provides effective short-term cardiopulmonary support.