Pediatric cardiac catheterization has its special aspects, mainly in the following aspects. I. Preoperative treatment of cardiac catheterization 1. Severe cyanotic preconditioning that depends on the opening of the arterial catheter to survive, such as PA/IVS, TGA/IVS, left heart lesions (IAA, COA), etc., PGE should be given promptly before surgery to maintain the opening of the arterial catheter by continuous 24-hour intravenous drip, correcting acidosis, avoiding high concentration, and continuous oxygen inhalation. 2, left-to-right shunt type of preconditioning, the presence of congestive cardiac insufficiency, preoperative should be given timely and appropriate treatment, commonly used drugs: digoxin, kibbutzol and diuretics. 3, TOF preoperative hypoxic episodes, should be given to the heart 1-3mg/kg / d, divided into 2 oral; in order to prevent intraoperative hypoxic episodes, half an hour before surgery to give morphine 0.05mg/kg. 4, cyanotic preconditioning, persistent hypoxemia caused by increased red blood cell compensation, when the HCT reaches 60% or more, easy to form thrombus. HB>18- 20g/dl, low molecular dextrose 10-20ml/kg/d 3 days before surgery; when HB>22-24mg/dl and HCT>65%, plasma-blood replacement dilution should be performed, i.e. fresh frozen plasma 15-20ml/kg. Cyanosis Precocious heart disease such as HB.