小循环心功能检测法评估心脏瓣膜替换术患者手术前后心功能状况

Clinical Significance of Right Chest Electric Admittance Plethysmography in the Evaluation ofCardiac Function in Patients Undergoing Heart Valve Replacement

目的：探讨心脏瓣膜替换术患者手术前后小循环心功能检测法评估患者心功能状况的价值。方法：２０例风湿性心脏瓣膜病患者在体外循环下替换了人工机械二尖瓣和（或）主动脉瓣，按术后是否使用呼气末正压通气分组：Ａ组使用呼气末正压［０．７ｋＰａ（５．２５ｍｍＨｇ）］；Ｂ组不使用呼气末正压通气。应用小循环心功能检测法对手术前后小循环各项参数进行观察，同时行Ｓｗａｎ－Ｇａｎｚ漂浮导管测定术后肺动脉楔压，将两者测定值进行对比分析并求两者间的相关关系。结果：患者术前肺动脉容积波（ｈｚ）、肺动脉、肺静脉容积波变化比值（ｈｃ／ｈｚ）、射血前期（Ｑｊ间期）、射血前期（Ｑｊ间期）与射血期（ｊｚ间期）比值（Ｑｊ／ｊｚ）均有明显异常，术后早期ｈｃ／ｈｚ、Ｑｊ／ｊｚ恢复至正常范围，其他参数均有不同程度改善。术后射血前期（Ｑｊ间期）随呼气末正压通气压力增加而时间延长，射血期（ｊｚ间期）相对缩短；ｈｃ／ｈｚ在Ａ组明显高于Ｂ组，且与肺动脉楔压间呈显著正相关。结论：小循环心功能法检测的肺动脉血容积波、肺静脉血容积波变化与肺动脉楔压呈正相关关系。小循环心功能检测法作为评估心功能状况的无创性方法具有简便敏感的特点，为评价心脏瓣膜手术的疗效提供了新的依据。

? Objective:To study the clinical significance of changes of index estimated by right chest electric admittance plethysmography and its value in evaluating the cardiac function in patients undergoing heart valve replacement. Methods:Twenty patients of rheumatic heart disease underwent mistral and/or aortic valve replacement using prosthetic mechanical valves under cardiopulmonary bypass (CPB).The patients were divided into two groups.Group A used the positive endexpiratory pressure(PEEP)07kPa(525mmHg)and group B without PEEP.At the same time,SwanGanz catheter was introduced into pulmonary artery and pulmonary capillary wedge pressure(PCWP)was obtained for comparative study of the two methods. Results:The value of hz,the ratio hc/hz,the Qj interval,the ratio of Qj/jz were dramatically abnormal and the ratio of hc/hz and the ratio of Qj/jz interval turn to normal after operation.Furthermore,the Qj interval prolonged apparently with the increase of PEEP and the jz interval shortened in group A.The hc/hz ratio in group A was extremely higher than that in group B and was positively correlated to PCWP. Conclusion:A marked correlation exists between PCWP and the parameters of volume changes of pulsating blood flow in pulmonary artery and vein.The right chest electric admittance plethysmography might be an useful method to evaluate the postoperative cardiac function.