We resected a myxedema in left atria for a pregnant woman with 28 weeks on December 28,2006,whose heart was ampliative,heart function was 2-3 level.We perfused with normothermic and high flow ECC method.ECC time was 69 min.The aortic cross-clamp time was 45min.The assisted time was 14min.the volume of ultrafiltration was 1200ml.Priming solution included 200ml fresh plasma,20g albumin,500ml lactic Ringers solution,50ml 5% sodium bicarbonate,20mg heparin,0.5g antibiotic,0.5g 10% calcium gluconate injection,25mg Progesterone,10mg dexamethasone.