摘要目的　对院内心脏骤停患者于心肺复苏期间行经食管超声心动图检查,以进一步探讨心肺复苏时的血液动力学机制.方法　对6例院内心脏骤停患者依照进一步心血管生命支持指南行心肺复苏术.于心肺复苏15 min内,在喉镜指引下,插入多平面食管超声探头,采用二维及脉冲波多普勒超声心动图技术,观察整个心肺复苏过程中二尖瓣、三尖瓣和主动脉瓣的运动状况,左室内径、胸主动脉内径的变化和二尖瓣、主动脉瓣的血流频谱.结果　所有的6例病人,胸按压时,二尖瓣和三尖瓣关闭,同时主动脉瓣开放,前向血流自心室进入体循环和肺循环；发生在胸按压时的主动脉瓣峰值前向血流速度为58.8±11.6?cm/s.而在按压放松时,主动脉瓣关闭伴房室瓣迅速开放,出现心室充盈,二尖瓣峰值前向血流速度为60.6±20.0?cm/s.有5例病人在按压期出现二尖瓣反流,提示存在着室至房的压力阶差.所有的6例病人于胸按压时出现左室内径减小和胸主动脉内径增加,表明直接的心室受压是前向血流产生的机制.结论　上述资料支持心泵理论是人类心肺复苏时产生前向血流的主导性机制.

abstractsObjective Transesophageal echocardiography was performed during closed-chest cardiopulmonary resuscitation (CPR) in in-hospital cardiac arrest to further explore the hemodynamic mechanism of CPR. Methods CPR attempts were performed according to advanced cardiovascular life support guidelines in 6 cases of in-hospital cardiac arrest. Multi-plane transesophageal echocardiography was carried out within 15 min of initiation of CPR. Throughout CPR, the motion of the mitral, tricuspid and aortic valves, the changes in the left ventricular cavity size and the thoracic aortic diameter were observed. Trans-mitral and trans-aortic Doppler files of blood flow were also documented. Results A closure of the mitral and tricuspid valves with simultaneous opening of the aortic valve occurred exclusively during chest compression, resulting in forward blood flow in the pulmonary and systemic circulation. Peak forward aortic flow at a velocity of 58.8±11.6?cm/s was recorded during the compression phase. Whereas, a closure of the aortic valve and rapid opening of the atrioventricular valves associated with ventricular filling during relaxation of chest compression was noted in all 6 patients. Peak forward mitral flow at a velocity of 60.6±20.0?cm/s was recorded during the release phase. Mitral regurgitation during the chest compression period was detected in 5 patients, reflecting a positive ventricular-to-atrial pressure gradient. A reduction in the left ventricular chamber and an increase in the thoracic aortic diameter during the compression phase was found in all patients, indicating that direct cardiac compression contributed to forward blood flow. Conclusion These observations favor the cardiac pump theory as the predominant hemodynamic mechanism of forward blood flow during CPR in human beings.