Williams syndrome (WS) is a rare congenital developmental disorder caused by the deletion of between 26 and 28 genes on chromosome 7q11.23. For patients with WS, in view of the particularity of the supravalvular aortic stenosis, choosing appropriate arterial cannula, maintaining higher perfusion pressure as well as strengthening myocardial protection during cardiopulmonary bypass (CPB) is essential to the clinical outcome. Here, we report a child with pulmonary artery valvular stenosis who failed to wean off CPB because of malignant arrhythmias and cardiac insufficiency after surgical correction of pulmonary valvular stenosis. With the assistance of extracorporeal membrane oxygenation (ECMO), emergency cardiac catheterization revealed supravalvular aortic stenosis (SVAS), which suggests a suspected missed diagnosis of WS. Finally, under the support of ECMO, the cardiac function gradually returned to normal, and the child was discharged 23 days after surgery.

威廉姆斯综合征 (WS) 是一种罕见的先天性发育障碍，由染色体 7q11.23 上的 26 至 28 个基因缺失引起。对于WS患者，鉴于主动脉瓣上狭窄的特殊性，选择合适的动脉插管、维持较高的灌注压以及加强体外循环(cardiopulmonary bypass, CPB)期间的心肌保护对临床转归至关重要。在这里，我们报告了一名患有肺动脉瓣膜狭窄的儿童，由于恶性心律失常和肺动脉瓣膜狭窄手术矫正后的心功能不全而未能停止 CPB。在体外膜肺氧合 (ECMO) 的帮助下，紧急心导管检查显示主动脉瓣上狭窄 (SVAS)，这表明疑似 WS 漏诊。最后，