经心脏右向左分流 (ＲＬＳ)的反常栓子是血栓栓塞性卒中的重要原因。经食管超声心动描记术 (ＴＥＥ)是诊断ＲＬＳ的金标准 ,但ＴＥＥ是半创伤性检查 ,不适于危重及不合作患者的检查。对比增强经颅多普勒超声 (ＴＣＤ)是ＴＥＥ理想的替代检查 ,静脉注射的超声增强剂直接通过ＲＬ Abnormal embolism of the right to left shunt (RLS) is an important cause of thromboembolic stroke. Transient esophageal echocardiography (TEE) is the gold standard for the diagnosis of RLS, but the TEE is a semi-traumatic test that is unsuitable for screening in critically ill and uncooperative patients. Contrast-enhanced transcranial Doppler ultrasound (TCD) is an ideal alternative to TEE, intravenous ultrasound enhancer directly through the RL