[Suspended Ventricular Septal Defect Closure Due to Heparin Resistance;Report of a Case].

We present a case of heparin resistance whereby open heart surgery was discontinued. A 53-year-old woman who was diagnosed with ventricular septal defect and atrial septal defect was scheduled for intracardiac repair. However, after intravenous heparin (400 U kg-1) supplementation, the activated clotting time (ACT) increased only to seconds. The operation was discontinued because the addition of heparin( 200 U kg-1) did not show sufficient prolongation of ACT, fully indicative of heparin resistance. Additional antithrombin III concentrate was also ineffective. Postoperative study of the administration of heparin in vitro to the patient's serum showed the probability of transient heparin resistance arising from the stress of surgery.