2例均是 2 0 0 0 - 12～ 2 0 0 1- 0 3在我院住院患者 ,均在劳力性呼吸困难基础上伴有晕厥发作。例 1于入院前 3ｄ内发作晕厥 4次 ,例 2下肢肿胀、压痛 ,于入院前 12ｈ发作晕厥 1次。心动图、血气分析、心脏超声均有典型肺栓塞改变。多普勒超声均提示 :下肢静脉血栓形成。入院 Both of the 2 cases were inpatients in our hospital from 2000 to 12 2000. All patients had syncope on the basis of exertional dyspnea. Example 1 3 days before admission, onset of syncope 4 times, 2 cases of lower extremity swelling, tenderness, syncope occurred 12h before admission. Cardiogram, blood gas analysis, cardiac ultrasound have a typical change of pulmonary embolism. Doppler ultrasound tips: lower extremity venous thrombosis. Admission