Higano S T, Oh J K, Ewy G A, Seward J B
Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN 55905.
Mayo Clin Proc. 1990 Nov;65(11):1432-40. doi: 10.1016/s0025-6196(12)62167-3.
Despite years of research, the mechanism of forward blood flow during closed chest cardiac massage remains controversial. Two theories have been suggested: the cardiac pump theory and the thoracic pump theory. Transesophageal echocardiography offers a new approach for study of the flows and cardiac morphologic features during chest compressions in humans. Case reports are presented to illustrate the use of transesophageal echocardiography during cardiopulmonary resuscitation. The findings included right and left ventricular compression, closure of the mitral valve during compression, opening of the mitral valve during the release phase, and atrioventricular valvular regurgitation during compression, indicating a positive ventricular-to-atrial pressure gradient. These findings suggest that direct cardiac compression was the predominant mechanism of forward blood flow during cardiopulmonary resuscitation in these patients. An understanding of the actual mechanisms involved is necessary if improved cardiopulmonary resuscitative techniques or adjuncts are to be rationally developed for enhancing the outcome of resuscitation.
尽管经过多年研究，但胸外心脏按压期间正向血流的机制仍存在争议。已经提出了两种理论：心脏泵理论和胸廓泵理论。经食管超声心动图为研究人体胸部按压期间的血流和心脏形态特征提供了一种新方法。现呈现病例报告以说明经食管超声心动图在心肺复苏中的应用。研究结果包括左右心室受压、按压期间二尖瓣关闭、放松阶段二尖瓣开放以及按压期间房室瓣反流，提示心室至心房存在正压梯度。这些结果表明，在这些患者的心肺复苏过程中，直接心脏按压是正向血流的主要机制。如果要合理开发改进的心肺复苏技术或辅助设备以提高复苏效果，就有必要了解其中实际涉及的机制。
