快速左心耳起搏对犬心房构型、心功能及病理组织学特点改变的时间进程研究

目的 探讨慢性心房颤动(Atrial Fibrillation,AF)犬随时间进程心房构型、心功能、病理组织学及超微结构的变化特点.方法 14只比格犬随机分为起搏组(n=7)和对照组(n=7),于左心耳缝植起搏电极,连接实验用VOO型起搏器(频率为400次/min),快速持续起搏8周,建立犬慢性AF模型.分别于0、1、2、4、6、8周时应用超声心动图测量左房横径及心室射血分数,实验结束后取心房肌组织用光镜和电镜观察心房肌的超微结构.结果 (1)心脏超声结果显示8周的左房内径与起搏前比较明显增加,差异有统计学意义(P<0.01),在起搏1周时左房内径已经明显增加,随后2、4、6、8周的左房内径出现逐渐增加趋势.同时,起搏8周心室射血分数与起搏前相比显著降低,差异有统计学意义(P<0.01),心室射血分数1周时已经明显降低,与起搏前比较,差异有统计学意义(P<0.01),随后2、4、6、8周心室射血分数出现逐渐降低趋势.而对照组起搏电极植入前后均未发生明显变化.(2)起搏犬心房肌细胞明显肥大,变性,心肌纤维排列紊乱,线粒体增多、体积变大,细胞间存在不同程度的纤维化及间质胶原增生和糖原沉积.结论 高频起搏左心耳8周建立的慢性AF模型,心肌超微结构、心房构型和心功能发生明显改变,引起心房结构重构和收缩功能重构,这是发生心房颤动的重要原因之一.

Study on rapid left atrial appendage pacing-induced chronic atrial fibrillation model atrial sizes and left ventricular function and histologic changes in beagle dogs

Objectives To observe the changes of left atrial sizes,heart function,morphological and ultrastructural changes of chronic atrial fibrillation model by rapid left atrial appendage pacing eight weeks in Beagle dogs. Methods 14 Beagle dogs were randomly divided into two groups:control group (n=7),rapid pacing group (n=7):group pacing was paced at 400 beat per minute for eight weeks at the left atrial appendage. After 8 weeks of rapid left atrial appendage pacing,chronic AF model came into being. The left atri...