开胸山羊心房颤动模型的建立及心房颤动转复窦性心律后组织学重构逆转的研究

发布时间：2018-05-13 03:41

本文选题：心房颤动 + 起搏　；参考：《南京医科大学》2007年硕士论文

【摘要】： 第一部分开胸建立山羊心房颤动模型可行性的研究【目的】探讨开胸缝合起搏电极于左心耳快速起搏建立持续性心房颤动(AF)模型的可行性。【方法】山羊18只，平均体重(15±6)kg，随机分为房颤组(12只)与假手术对照组(6只)。左侧第五肋间切口，开胸暴露心脏，缝合起搏电极于左心耳。房颤组起搏电极尾端连接高频脉冲发生器，假手术组直接将电极缝埋于皮下。术后支持治疗一周，后以400次／分频率左心耳连续起搏12周，诱导心房颤动。心电图记录山羊的体表肢体导联心电图变化，电生理检查心房有效不应期(AERP)改变。房颤持续时间大于15分钟定义为持续性房颤。HE染色后光学显微镜观察左心房组织学变化，电镜观察左心房超微结构的变化。【结果】房颤组1只山羊术后死亡，12周连续起搏后2(18.18％)只山羊自发形成房颤，心电图显示典型的心房颤动表现。房颤组8／11(72.73％)只山羊经程序电刺激诱导出持续性房颤，3／11(27.27％)只山羊诱导出非持续性房颤。电生理检查AF组AERP缩短。光学显微镜观察对照组细胞排列整齐，房颤组心肌细胞排列紊乱，胞浆淡染。电镜检查对照组心肌纤维Z线清晰，房颤组心肌纤维溶解明显，闰盘受损，Z线消失；线粒体增多、体积变大，内质网模糊、有的出现空泡样改变。【结论】开胸左心耳起搏能诱导多数山羊发生持续性心房颤动，是一种新的、比较可靠的持续性房颤动物模型建立方法。第二部分心房颤动转复窦性心律后组织学重构逆转的研究【目的】观察心房颤动(房颤，AF)的组织学重构在转复并维持窦性心律后能否逆转。【方法】山羊18只，分为假手术对照组、AF组和AF复律组。开胸缝合起搏电极于左心耳，400次／分快速起搏12周建立AF模型。分别于手术前、AF3个月及转复窦性心律3个月后超声心动图测量左心房内径(LAD)、左室射血分数(LVEF)等指标。取左心房组织，电镜观察心房肌超微结构的改变，Masson染色观察纤维化程度，，半定量逆转录-聚合酶链反应(RT-PCR)检测MMP-2 mRNA含量的变化。【结果】AF组心肌细胞溶解、线粒体增大等超微结构改变明显；心房显著扩大；心肌间质内胶原沉积增加，MMP-2 mRNA表达水平上调(从0.40±0.12上升至0.70±0.16，P＜0.05)。AF复律组超微结构的改变基本恢复至正常，LAD明显缩小但未降至对照组水平，纤维化程度减轻，MMP-2 mRNA由0.70±0.16降为0.52±0.10(P＜0.05)，但与对照组相比仍明显升高，差异有显著意义。【结论】AF转复并维持窦性心律后，组织学重构缓慢逆转，且在程度上不一定能完全恢复。
[Abstract]:The first part: feasibility study on establishing Goat Atrial Fibrillation Model with Thoracotomy [objective] to investigate the feasibility of establishing the model of persistent atrial fibrillation (AF) with open chest suture pacing electrode in the left atrial appendage. [methods] 18 goats with an average body weight of 15 卤6 kg were randomly divided into atrial fibrillation group (n = 12) and sham operation control group (n = 6). Left fifth intercostal incision, open chest to expose heart, suture pacing electrode in left atrial appendage. In the atrial fibrillation group, the end of the pacing electrode was connected to the high frequency pulse generator, and the slotted electrode was buried directly in the sham operation group. Atrial fibrillation was induced by 400 / min left atrial appendage pacing for 12 weeks. Electrocardiogram (ECG) recorded the changes of electrocardiogram (ECG) and electrophysiological examination (AERP). The duration of atrial fibrillation longer than 15 minutes was defined as the histological changes of left atrium observed by optical microscope after persistent atrial fibrillation. The ultrastructure of left atrium was observed by electron microscope. [results] one goat in the AF group died after 12 weeks of continuous pacing. The goat spontaneously developed atrial fibrillation. The electrocardiogram showed the typical manifestation of atrial fibrillation. In the atrial fibrillation group (8 / 1172.73), continuous atrial fibrillation was induced by programmed electrical stimulation in 3 / 1127.27 goats. Electrophysiological examination showed that AERP was shortened in AF group. The cells of the control group were arranged neatly under optical microscope, and the cardiomyocytes of the AF group were disordered and the cytoplasm was light stained. Electron microscopic examination showed that the Z line of myocardial fiber in control group was clear, and that in atrial fibrillation group, the myocardial fiber dissolved obviously, the damaged Z line of intercalated disc disappeared, the mitochondria increased, the volume of mitochondria increased, the endoplasmic reticulum was blurred, [conclusion] Open left atrial auricle pacing can induce persistent atrial fibrillation in most goats, which is a new and reliable method to establish animal model of persistent atrial fibrillation. The second part of the study on the reversal of histological remodeling after atrial fibrillation was converted to sinus rhythm [objective] to observe whether the histological remodeling of atrial fibrillation (AF) could be reversed after the restoration and maintenance of sinus rhythm. [methods] Eighteen goats were divided into sham operation control group (AF group) and AF group (AF group). Open chest suture pacing electrode was used in 12 Zhou Jianli AF model. Left atrial diameter (lad) and left ventricular ejection fraction (LVEF) were measured by echocardiography at 3 months before operation and 3 months after sinus rhythm conversion. The ultrastructural changes of atrial muscle were observed by electron microscope. The degree of fibrosis was observed by Masson staining. The changes of MMP-2 mRNA content were detected by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). [results] Myocardial cells in AF group were dissolved. The ultrastructural changes such as mitochondrial enlargement and atrial enlargement were obvious. Collagen deposition in myocardium increased the expression of MMP-2 mRNA (from 0.40 卤0.12 to 0.70 卤0.16) (P < 0.05). The ultrastructural changes in the cardiomyocyte interstitial collagen deposition group returned to normal, but not to the control group. The degree of fibrosis of MMP-2 mRNA decreased from 0.70 卤0.16 to 0.52 卤0.10 (P < 0.05), but it was still significantly higher than that of the control group. [conclusion] after AF was restored and maintained sinus rhythm, the histological remodeling was reversed slowly, and the degree could not be completely recovered.
【学位授予单位】：南京医科大学
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：R541.75;R-332

【参考文献】