兔肺静脉心肌袖组织学特性研究

近年来随着导管射频消融治疗心房颤动 (房颤 )技术的开展 ,发现大多数阵发性房颤起源于肺静脉入口近段[1 4 ] ,提示肺静脉在房颤的发生中起重要作用。肺静脉注入左心房后壁 ,与心房连接处无瓣膜 ,组织学上可看到肺静脉入口处的平滑肌细胞中有横纹肌成分 ,即心肌细胞呈类似袖套样延伸到肺静脉内 ,而且上肺静脉比下肺静脉的袖套样结构更宽更完善[5] ,形成心肌袖 (myocardialsleeve)。本实验通过对兔肺静脉肌袖解剖结构及组织学特性的观察探讨局灶性房颤起源于肺静脉的形态学基础。资料和方法实验标本的取材　健康新西兰大耳白兔 12只 ,雌雄不…     

人体肺静脉组织学观察12例

目的　研究肺静脉的组织学特性 ,以探讨肺静脉触发性阵发性心房颤动的解剖学基础。方法　通过HE染色、Masson染色和α Smoothmuscleactin的免疫组化 ,对 12例非心脏原因死亡的尸检标本肺静脉进行组织学研究。结果　共分析肺静脉标本 4 7支 ,其中 4 5支肺静脉可见有左心房心肌的延伸 :心肌袖。上肺静脉的心肌袖明显比下肺静脉延伸的距离长 [左上肺静脉 (12 6± 3 6 )mm ,左下肺静脉 (5 7± 3 2 )mm ,P <0 0 5 ;右上肺静脉 (10 2± 4 7)mm ,右下肺静脉 (4 4± 3 0 )mm ,P <0 0 5 ],右下肺静脉口的直径明显小于其余的肺静脉 [分别为 (12 2± 1 8、15 2± 3 1、15 3±1 9、15 0± 1 2 )mm ,P <0 0 5 ]。肺静脉内心肌纤维集合成束 ,走行不规则、方向各异 ,心肌束在肺静脉同一周径上的分布不均一。结论　非心脏原因死亡的人体肺静脉存在心房肌的延伸即心肌袖 ,其心肌纤维分布不均匀 ,走行方向各异 ,可能是产生触发性阵发性心房颤动的解剖学基础。     

人的肺静脉前庭心肌的病理组织学特点

目的 虽然导管消融治疗心房颤动(房颤)已取得了较高的成功率,但房颤的机制仍不十分明确,目前临床应用的导管消融术式多与肺静脉前庭有关,因此,肺静脉前庭的解剖结构与电生理特点成为人们关注的热点.本实验通过对比观察左心房、肺静脉及肺静脉前庭的组织学特点,探讨房颤发生与维持的机制.方法 10例非心脏原因死亡的成人尸检标本.观察肺静脉的分布与走行,沿肺静脉走行剥离肺静脉与心包及周围结缔组织,剪下左心房与肺静脉.观察肺静脉前庭部肌束的分布与走行.并同时将标本由近至远心端分别环行剪取左上及右上肺静脉、左上及右上肺静脉前庭、左心房3 mm宽组织标本.将组织置于4%的多聚甲醛溶液中固定1周以上进行取材.经酒精脱水,石蜡包埋,分别作纵向和横向连续切片,常规HE染色.选取部分标本进行Masson染色.随机选取肺静脉前庭部纵切3 mm宽的组织标本,进行PGP9.5单克隆抗体S-P免疫组化染色.观察肺静脉前庭心肌厚度、细胞分布与排列特点、神经分布特点.结果 (1)肺静脉前庭内心肌平均厚度较左心房薄[(2.6±0.4)mm对(3.0±0.5)mm,P=0.047].(2)细胞分布:心肌纤维自左心房至肺静脉前庭向肺静脉连续延伸,逐渐变薄,心肌细胞数逐渐减少.与左心房心肌细胞分布相比较,肺静脉前庭处,从横切面上可以观察到心肌在肺静脉前庭内分布不均一,有的部分相对数量较多而有的部分则较稀疏.(3)细胞排列:从纵切面观察,左心房心肌纤维总体呈横行排列,密度均匀,而肺静脉前庭内的心肌纤维的走行方向呈横行、纵行或斜行等不规律排列,在近心内膜部分肌束排列较紧密,近心外膜部分则排列较疏松.随着向肺静脉延伸,心肌细胞分布逐渐稀疏,心内膜和心外膜的差别渐无.(4)特殊细胞:未观察到有结样细胞或形成传导束的特殊细胞.见到染色呈深褐色的特殊细胞.(5)免疫组化染色结果,肺静脉前庭的心肌细胞处存在PGP9.5免疫组化染色阳性的神经纤维.结论 人的肺静脉前庭内心肌细胞的分布不均匀、排列紊乱,可能是发生心律失常的结构基础.有丰富的神经纤维分布,可能解释肺静脉前庭内易于出现自律性、不应期、传导速度等电生理特征异常的电活动,并触发或维持房颤.     

风湿性心脏瓣膜病房颤肺静脉组织学及pgp9.5蛋白分布研究

目的:探讨风湿性心脏瓣膜病合并房颤病人肺静脉组织学及pgp9.5(product gene protein 9.5)蛋白表达的变化特点。方法:选取风湿性心脏瓣膜病行瓣膜置换术病人26例,术中收集右上肺静脉标本。将病人分为房颤心律组(n=14),窦性心律组(n=12),对肺静脉标本行HE染色及pgp9.5蛋白Envension免疫组织化学染色。结果:与窦性心律组相比,房颤组心肌袖部心肌细胞肥大,肌束间间隙较大,排列更紊乱;脂肪垫及心肌组织有大量表达pgp9.5蛋白的细胞。结论:风湿性心脏病合并房颤致肺静脉心肌袖部心肌细胞肥大,间隙增宽;免疫组化染色表明肺静脉组织有大量表达pgp9.5蛋白的细胞存在。     

风湿性心脏瓣膜病房颤肺静脉组织学及pgp9．5蛋白分布研究

目的:探讨风湿性心脏瓣膜病合并房颤病人肺静脉组织学及pgp9.5(product gene protein 9.5)蛋白表达的变化特点.方法:选取风湿性心脏瓣膜病行瓣膜置换术病人26例,术中收集右上肺静脉标本.将病人分为房颤心律组(n=14),窦性心律组(n=12),对肺静脉标本行HE染色及pgp9.5蛋白Envension免疫组织化学染色.结果:与窦性心律组相比,房颤组心肌袖部心肌细胞肥大,肌束间间隙较大,排列更紊乱;脂肪垫及心肌组织有大量表达pgp9.5蛋白的细胞.结论:风湿性心脏病合并房颤致肺静脉心肌袖部心肌细胞肥大,间隙增宽;免疫组化染色表明肺静脉组织有大量表达pgp9.5蛋白的细胞存在.     

迷走神经在肺静脉起源的心房颤动中的作用研究进展

心房颤动（简称房颤）是临床上较为常见的心律失常之一，随着人口的老龄化加速，其发病率在今后数十年中将逐步增加。而房颤作为能引起脑卒中和心功能障碍等严重危害人类生命和生活质量的并发症的重要危险因素，已经开始得到越来越多的关注。近几年，随着基础和临床研究不断开展并深化，对房颤发生与维持的机制有了比较深入的了解，其中肺静脉起源学说被认为是房颤研究方面最具突破性的进展，虽然其中仍然存在许多盲区，但这些进展仍给房颤的治疗带来了许多积极的变革。     

心房颤动肺静脉起源的电生理机制研究进展

心房颤动 (简称房颤 )是最常见的心律失常之一。房颤的肺静脉起源学说被认为是阵发性房颤研究方面最具突破性的进展 ,但是房颤肺静脉起源的电生理机制尚未完全阐明。近年来的电生理学研究显示自律性增高和触发活动可能是肺静脉肌袖电活动产生的机制。但是由于肺静脉的解剖和电生理特点造成的肺静脉内传导阻滞的存在 ,生理情况下 ,肺静脉电位很少能够激动心房导致房颤的发生。快速心房起搏 (rapidatrialpacing ,RAP)已经被证实是房颤研究中一种非常有价值的方法。在RAP或房颤后 ,诱发肺静脉电重构和心房电重构 ,有利于房颤的发生与维持。     

持续快速心房起搏对犬肺静脉肌袖组织结构的影响

探讨持续快速心房起搏对犬肺静脉肌袖组织结构的影响。 1 4条杂种犬 ,其中起搏犬 8只 ,对照犬 6只。起搏犬以 40 0次 /分的频率持续起搏右心房 9～ 1 0周 ,对照犬仅放置起搏导线及起搏器 ,但不起搏。 9～ 1 0周后对所有犬均进行心房颤动 (简称房颤 )的诱发 ,并取其肺静脉组织进行HE染色、Masson′s染色和电镜检查。结果 :终止起搏后起搏犬的持续房颤 ( >1 5min)诱发率为 87.5 % ( 7/8) ,显著高于对照犬 ( 0 % ,P <0 .0 1 )。起搏犬肺静脉肌袖组织的光镜特征为心肌细胞变性 ,胶原组织大量增生 ;电镜下变性心肌细胞的超微结构异常主要累及线粒体和肌原纤维。对照犬肺静脉肌袖组织的形态学未见明显病理改变。结论 :持续快速心房起搏可导致犬的肺静脉肌袖组织发生显著的形态学重构 ,后者可能与该模型房颤的机制有关。     

环肺静脉线性消融电学隔离肺静脉治疗100例心房颤动临床评价

目的探讨三维标测系统和单环状标测电极指导下行环肺静脉线性消融电学隔离肺静脉治疗心房颤动(房颤)的可行性和有效性。方法自2004年4月至2005年1月共对连续100例症状明显、发作频繁、抗心律失常药物治疗无效的房颤患者进行了在CARTO系统(76例)或EnSite-NavX系统(24例)指导下的环肺静脉线性消融术,消融终点为双侧肺静脉的彻底电学隔离。结果100例患者共完成200个环形消融环,肺静脉电学隔离率为95.0%。操作时间150～365(240±65)min,X线时间为23～61(37±12)min。其中8例(8.0%)复发患者接受了再次导管消融。随访5.5～12(10.2±5.7)个月,累计无房性快速心律失常率为85.0%。术后1、2、3、4、5、6个月时无房性快速心律失常率分别为66.0%、82.0%、87.0%、85.0%、85.0%、88.6%。并发症包括1例心脏压塞,经保守治疗后康复,1例患者出现无症状性肺静脉狭窄。结论在三维标测系统指导下,环肺静脉线性消融电学隔离肺静脉治疗房颤安全有效。     

肺静脉内射频消融温度与肺静脉狭窄的关系研究

目的探讨肺静脉内不同温度射频消融与肺静脉狭窄的关系.方法健康杂种犬30只,分成3组,经房间隔途径将温控电极导管置入肺静脉内进行消融,各组能量分别为50℃×60s,60℃×60s,70℃×60s.消融前、后均行选择性肺静脉造影,术后留养3个月,重复肺静脉造影后,处死,取心肌、肺静脉及肺组织作病理检查.结果50℃组1只犬在行房间隔穿刺时因心包填塞死亡,其余均顺利完成试验.共在肺静脉内72处行点状消融,50℃组、60℃组、70℃组分别为20、26、26处.右上肺静脉、右下肺静脉、左上肺静脉和左下肺静脉分别为13、9、27、23处.50℃组肺静脉于消融后即刻及3个月后均未见狭窄.60℃组消融后即刻发现5处狭窄,3个月后仅遗留1处狭窄.70℃组消融后即刻有12处狭窄,3个月后复查仍有7处狭窄,发生率均明显高于50℃组及60℃组.结论肺静脉内射频消融温度为50℃及60℃时较为安全,70℃时肺静脉狭窄的发生率明显上升,提示消融温度应控制在60℃以减少肺静脉狭窄的形成.     

猪肺静脉肌袖PGP9.5免疫组织化学和组织学特点研究

目的 检测猪肺静脉肌袖的PGP9．5(protein gene pmduct9．5)抗原表达和组织学特点，初步探讨肺静脉源性心房颤动的发病机制。方法 健康家猪11只，取其肺静脉，10％中性福尔马林固定，石蜡切片行HE染色及SP免疫组织化学染色。结果 (1)HE染色显示，4个左上肺静脉的肌袖组织中观察到染色浅淡的单个苍白样细胞，2个肺静脉内膜下层见条索状聚集分布的苍白样细胞群；(2)免疫组织化学染色显示，6个左上肺静脉、2个右上肺静脉的肌袖组织中存在PGP9．5免疫组织化学染色阳性的细胞和神经纤维。结论 通过HE染色方法，观察到肺静脉肌袖组织中存在与窦房结P细胞形态相似的苍白样细胞，以及与心室内膜下束支形态相似的苍白样细胞群。应用免疫组织化学方法，证明这些细胞与心脏传导系统有相同的PGP9．5抗原表达。     

Anomalous pulmonary veins

The literature now embodies 133 case reports of anomalous drainage of pulmonary veins. Of these patients, partial drainage into the right atrium occurred in 75, and complete drainage into this chamber or its tributaries occurred in 56. Additional cardiovascular anomalies were present in 23 of the latter group of patients. Partial drainage of pulmonary veins into the right atrium is consistent with long life. In 56 reported cases of complete drainage of pulmonary veins into the right atrium, only 10 patients lived beyond the age of 8 months. The clinical diagnosis of complete drainage of pulmonary veins into the right atrium can be established by use of the cardiac catheter and the angiocardiogram. An additional case is described in which all of the pulmonary veins emptied into the superior vena cava in a male infant who lived to the age of 8 weeks.     

Electrophysiology of pulmonary veins

Pulmonary veins were found to be important foci for the genesis and maintenance of atrial fibrillation. Morphological studies have demonstrated the presence of complex anatomic structures and different types of cardiomyocytes in pulmonary veins. Numerous studies have suggested that the combination of reentrant and nonreentrant mechanisms (automaticity and triggered activity) are the underlying arrhythmogenic mechanisms of atrial fibrillation initiation from the pulmonary veins. Electropharmacological studies further indicated that pulmonary veins contained distinct arrhythmogenic activity. Several experimental models have been used to study the pulmonary vein electrical activity and demonstrate the precipitating factors for enhancing the pulmonary vein arrhythmogenic activity. The aim of this review article is to provide a critical overview of the current understanding of the basic and clinical electrophysiology of pulmonary veins and to underscore the importance of future research in this field.     

Morphometry of pulmonary veins in man

Resin casts of the pulmonary veins were made from the lungs of two women and one man. Branches were classified by Strahler orders, the number of branches in each order was counted, and their mean diameter and mean length determined. All branches down to 1.0 mm diameter were studied on each of the casts, and a sample of branches down to 0.2 mm diameter was studied on one cast. From the data thus obtained a dimensional model of the pulmonary veins was elaborated and compared with a previously obtained model of the pulmonary arteries. The venous volume was calculated to be 74 ml, 80% of which is located in the upper six orders.     

CT of the pulmonary veins

Atrial fibrillation (AF) is a common cardiac rhythm disturbance and its incidence is increasing. Radiofrequency catheter ablation (RFCA) is a highly successful therapy for treating AF, and its use is becoming more widespread; however, with its increasing use and evolving technique, known complications are better understood and new complications are emerging. Computed tomography (CT) of the pulmonary veins, or more correctly, the posterior left atrium (LA), has an established role in precisely defining the complex anatomy of the LA and pulmonary veins preablation and has an expanding role in identifying the myriad of possible complications postablation. The purposes of this article are: to review AF and RFCA; to discuss CT evaluation of the LA and pulmonary veins preablation; and to review the complications of RFCA focusing on the role of CT postablation.     

Ablation of superior pulmonary veins compared to ablation of all four pulmonary veins:

INTRODUCTION: Isolation of all pulmonary veins (PV) is advocated for treatment of paroxysmal atrial fibrillation (PAF). However, the superior PVs are responsible for most AF triggers, whereas the inferior PVs carry the higher risk for ablation-induced ostial stenosis. The aim of this study was to compare a superior PV isolation approach with isolation of all PVs for treatment of PAF. METHODS AND RESULTS: Fifty-two patients with PAF were randomized to either left superior pulmonary vein (LSPV) isolation followed by additional isolation of the right superior pulmonary vein (RSPV) in case of AF recurrence (group A, n = 27) or isolation of all four PVs followed by a repeat procedure in case of recurrence (group B, n = 25). At 1-year follow-up, 11 patients (41%) in group A and 8 patients (32%) in group B had AF relapse (P = 0.55). No significant differences in AF relapse were detected between groups at 3 and 12 months (log rank = 0.36, P = 0.54) and by Cox proportional hazards model analysis (P = 0.62). Nonsignificant PV stenosis was detected in two patients from group B. Total radiofrequency energy delivery and fluoroscopy and procedure times were lower in group A: 8.9 +/- 1.4 minutes vs 25.6 +/- 3.7 minutes (P < 0.001), 22.2 +/- 6.8 minutes vs 62 +/- 10.3 minutes (P < 0.001), and 131.8 +/- 26.5 minutes vs 222.2 +/- 32.3 minutes (P < 0.001), respectively. CONCLUSION: A staged superior PVs isolation approach confers equal success rates but with reduced radiofrequency energy delivery and fluoroscopy and procedure times compared to isolation of all PVs at the initial ablation attempt.     

Complete absence of pulmonary veins

Various types of pulmonary venous return abnormalities have been described in the literature. This report presents a case in which a 4-h-old neonate presented with cyanotic heart disease and respiratory distress. This neonate was subsequently shown to have complete absence of the pulmonary veins (CAPV), a previously undescribed malformation. The case summary describes the physical findings, radiographic and electrocardiographic features, cardiac catheterization data, and results from autopsy. A discussion of the case, theories of embryological etiology for this malformation, and differential diagnoses follow. Surgical treatment for CAPV is not yet possible.