隐匿性束支阻滞

隐匿性束支阻滞是一个含义广、种类多、表现不一的心电图概念。随着心脏电生理学技术的发展和普及 ,对隐匿性束支阻滞的认识不断深化和拓宽。一、束支的解剖学特点1.希氏束及分支房室结深部迷路样纤维逐渐移行为规整、平行排列的传导纤维构而成希氏束。希氏束的前半部分(穿越部分 )穿过中心纤维体 (约 10ｍｍ ) ,后半部分沿室间隔膜部的下缘行走 ,该段称为非穿越部 (约10ｍｍ) (图 1)。此后 ,希氏束在室间隔膜部的左侧、室间隔肌部的上缘分出瀑布状、扁而宽的左束支。左束支的第一条分支分出之前称为希氏束未分叉部 ,分出左束支后 ,希氏束末…     

室间隔缺损修补术致希氏束自律性心动过速1例

患儿女性,2岁.临床诊断:先天性心脏病,室间隔缺损.1998年11月2日在我院全麻低温体外循环下行室间隔缺损修补术.术中切开右心房,经三尖瓣口见室间隔缺损位于膜部,缺损被三尖瓣隔瓣遮盖后,遗留4×4mm的分流口.带垫片褥式缝合一针闭合室间隔缺损.心脏自动复跳,表现为完全性房室传导阻滞.再次阻断主动脉,拆除原来缝线,垂直三尖瓣环切开三尖瓣隔瓣,暴露原发室间隔缺损,加垫片褥式缝合两针闭合室间隔缺损.心脏复跳后仍为     

先天性室间隔缺损室上嵴解剖形态观察

本组３８例先天性室间隔缺损标本，共有４３个缺损，除去３个膜部小室间隔缺损、１个前窦部伴１个后窦部肌肉缺损外，其余３４例３８个缺损均与漏斗间隔及隔缘肉柱畸形有关。最常见为隔缘肉柱下肢发育不良，或隔缘肉柱下肢与漏斗间隔未对合；次之为漏斗间隔上股或下股肌肉缺如，或上、下股肌肉对合不良；漏斗间隔向隔缘肉柱深层所发出的隔束有缺损者少见。本组漏斗乳头肌起点异常者有２８例。常见异常起点有漏斗间隔下缘、漏斗间隔所发出的壁束或隔缘肉柱上肢等。     

国产室间隔封堵器治疗膜部室间隔缺损的应用

目的：探讨国产室间隔封堵器治疗膜部室间隔缺损的效果。方法：回顾性总结3例膜部室隔缺损（VSD）用国产室间隔封堵器治疗的资料。结果：2例成功封堵VSD，1例封堵器到位后严重变形，无法封堵，转外科手术。结论：国产室间隔封堵器有实用价值，但质量不完全可靠。     

婴幼儿复杂先天性心脏病的外科治疗——房室间隔缺损

房室间隔缺损(AVSD)既往又称为房室管缺损、房室共同通道或心内膜垫缺损，是一较少见的复杂心脏畸形。目前则特指房室瓣结构和功能异常伴房室瓣上下相邻房间隔和室间隔缺损的先天性心脏畸形。Castaneda等提出，AVSD无论畸形变异如何，应当同时具有下列共同形态学特点：①房室间隔缺损；②房室瓣膜异常；③室间隔呈勺形异常使流人道与心尖距离缩短；④非镶嵌状的主动脉瓣同时伴有左室流出道呈鹅颈样形态，使心尖与左室流出道的距离变远；⑤冠状窦、房室结与室间隔近端传导系统均向下异位。     

无导线房室同步起搏器 Micra AV植入一例

患者女性，81岁。因“呼吸困难，胸闷20余天”入院。心电图示二度Ⅱ型房室传导阻滞，心室率33次/分；动态心电图示完全性房室传导阻滞。选择经静脉途径安置无导线起搏器Micra AV。术中经左侧股静脉放置临时起搏电极行临时保护性起搏；经右侧股静脉途径放置Micra AV于右室间隔部，测试起搏阈值0.25 V/0.24ms,感知9.8 mV,阻抗1 120Ω。术后起搏功能正常。     

经皮室间隔缺损封堵术后迟发Ⅲ度房室阻滞一例

18岁女性室间隔膜部缺损患者 ,行经皮室间隔缺损封堵术 ,手术顺利 ,封堵完全 ,术后恢复好。术后第 5天出现Ⅲ度房室阻滞 ,予氢化考的松静脉滴注 6天 ,症状消失 ,心电图恢复正常 ,随访至今无不适。经皮室间隔缺损封堵术后可发生迟发性房室阻滞 ,原因可能为局部炎症水肿所致。     

膜周部室间隔缺损合并三尖瓣反流的机制探讨

目的通过术前、术后超声心动图和彩色多普勒检查及手术所见,评价及明确膜周部室间隔缺损合并三尖瓣反流的机制.方法通过13例膜周部室间隔缺损合并三尖瓣反流的临床资料,经胸超声心动图术前诊断及术后复查,结合术中所见,观察膜周部室间隔缺损和三尖瓣反流的关系.结果所有病例均为中等膜周部室间隔缺损,中等量的左向右分流,心室收缩期,二维超声心动图可见典型的三尖瓣前向运动及三尖瓣呈开放状态.彩色多普勒血流显象,大多数病例表现为经室缺的部分穿隔血流被隔瓣阻挡,但主要血流经三尖瓣隔瓣下缘穿过,冲击到三尖瓣的前瓣,导致三尖瓣反流.室缺修补后,三尖瓣反流消失.结论膜周室缺的穿隔血流可导致膜周室缺合并三尖瓣反流.二维超声心动图及彩色多普勒血流显象发现该现象,这是外科手术修补室缺的良好指征.     

应用Amplatzer封堵器关闭32例膜部室间隔缺损

目的　观察Amplatzer膜部室间隔缺损封堵器关闭膜部室间隔缺损的临床疗效及安全性。方法　经超声心动图及临床表现诊断为膜部室间隔缺损患者 ,如有临床症状但没有右向左分流 ,且膜部室间隔缺损的局部解剖结构满足以下条件 :(1)膜部室间隔缺损离主动脉瓣至少 1mm ,离三尖瓣隔瓣至少 3mm ;(2 )室间隔缺损的最窄直径小于 14mm ;(3)伴膜部室间隔瘤形成时 ,瘤体未影响右心室流出道 ;(4 )外科手术关闭膜部室间隔缺损后遗留的室间隔缺损 ,且对心脏的血流动力学有影响。在局部或全身麻醉下对患者行经导管Amplatzer双面伞膜部室间隔缺损的关闭治疗 ,手术中连续经胸或经食管超声心动图和X线监测。术后随访 3个月。结果　自 2 0 0 2年 6月至 2 0 0 3年 3月共有 32例患者行经导管Amplatzer双面伞膜部室间隔缺损的关闭治疗 ,其中男 17例 ,女 15例。超声测定膜部室间隔缺损直径为 3～ 8mm(平均 5 1mm) ,左心室造影测定膜部室间隔缺损的直径为 3～ 8mm(平均 4 4mm) ,所选Amplatzer膜部室间隔缺损封堵器直径为 4～ 12mm(平均 7 6mm)。堵闭操作技术成功率为 10 0 %。超声心动图示术后即刻残余分流为 11 5 % (少量分流 3 8% ,微量 7 7% ) ,2 4h后残余分流为 7 7% (为微量 ) ,3个月后有 3 8%的微量分流。手术中出现一过性     

射频消融疑难的房室结折返性心动过速

回顾分析２２４例房室结折返性心动过速的射频消融结果，３例消融未成功，占１．３％。其中１例消融房室结Ⅲ度房室阻滞后仍有心动过速发作，提示房室结双径路一部共同通道的存在。消融不成功的原因可能为慢径不是一组纤维，且在解剖上快，慢径极为邻近，易同时受损。     

The conducting tissues in primitive ventricular hearts without an outlet chamber.

We have studied the disposition of the cardiac conducting tissues in four hearts from situs solitus individuals possessing primitive ventricles without outlet chambers. These hearts correspond to the type of univentricular heart defined as common ventricle by Lev. All the hearts studied possessed normally positioned great arteries. Two groups, each consisting of two hearts, could be distinguished. The first type possessed a small posterior ridge which divided the posterior portion of the primitive ventricle into right and left ventricular sinuses. The papillary muscles to the atrioventricular valves were separate structures and arose on each side of this posterior ridge. The conducting tissues in these hearts arose from an atrioventricular node situated in the atrial septum but deviated posteriorly. The atrioventricular bundle pierced the fibrous annulus posteriorly and descended on the posterior ridge, lying to its left side. A bifurcation was not identified, and bundle branches were not present. The other two hearts had no posterior ridge. A common posterior papillary muscle supported both atrioventricular valves, and in one a marked anterior muscle bar produced obstruction of the pulmonary outflow tract. The connecting atrioventricular node was situated laterally in the right atrioventricular valve orifice, and the atrioventricular bundle descended into the right parietal wall of the primitive ventricle. A bifurcation and bundle branches were not observed. The disposition of conducting tissue in these hearts differs from that found in "primitive ventricle with outlet chamber" in that the connecting atrioventricular node and bundle are situated anteriorly and are intimately related to the transposed pulmonary artery outflow tract in the latter anomaly. The surgical significance of these findings is emphasized.     

Echocardiographic diagnosis of primitive ventricle with two atrioventricular valves.

Anatomical studies have shown that the pathognomonic feature of primitive ventricle is absence of that portion of the interventricular septum which interposes between the atrioventricular valves. The relation of this posterior septum to the atrioventricular valves is such that echocardiography should be a particularly suitable technique for showing its presence or absence. When a posterior septum is present, it is seen on an echocardiogram as a double echo between the two atrioventricular valves. It presence limits posterior movement of the septal cusp of the anterior atrioventricular valve. Absence of the posterior septum should, therefore, be seen echocardiographically as more than mere absence of the double septal echo. It should be possible to show unusual posterior excursion of the "septal" cusp of the anterior atrioventricular valve and apposition of the "septal" cusps of the atrioventricular valves during diastole. In most instances it should also be possible to demonstrate that the posterior great artery is in continuity with both atrioventricular valves. We have shown these echocardiographic features in 26 patients. The diagnosis of primitive ventricle has been confirmed at necropsy or at operation in 4 patients. In the other 22 patients in angiographic data are compatible with a diagnosis of primitive ventricle. Demonstration of these positive features at echocardiography is, therefore, of considerable value in the initial diagnosis of primitive ventricle and in particular its differentiation from other congenital malformations.     

Tricuspid atresia: analysis of coronary artery distribution and ventricular morphology.

There is still disagreement concerning the precise nature of the anterior ventricular chamber in "tricuspid atresia". Some argue that it is a right ventricle, while our own previous studies have suggested it is comparable to the outlet chamber seen in classical "single ventricle". We have compared the morphology of the anterior ventricular chambers in 48 examples of tricuspid atresia (absent right atrioventricular connection), 24 hearts with double inlet to the left ventricular chamber, and 15 hearts with pulmonary atresia and intact ventricular septum. Since there is further disagreement concerning the nature of the coronary artery which delimits the posterior extent of the ventricular septum in these hearts, we analysed the position of this vessel relative to external reference points on the atrioventricular junction. No significant difference was found with respect to the morphometry of hearts with tricuspid atresia (absent right atrioventricular connection) and those with double inlet. In both groups, however, significant differences were shown between hearts with ventriculoarterial concordance and discordance. Coronary artery disposition was the same in both groups and different from that found in hearts with pulmonary atresia and intact septum. We conclude that the ventricular morphology is comparable in hearts with tricuspid atresia (absent right atrioventricular connection) and those with double inlet to a left ventricular chamber. The lesions are distinguishable by their atrioventricular connection which is nevertheless univentricular in both.     

Dead-end tract of the conduction axis

In the definitive heart the anterior continuation of the main conduction axis is considered to be the right bundle branch. In this study three hearts from neonates and infants were examined in which this situation did not pertain. The conduction axis continued beyond the point of origin of the right bundle branch as a dead-end tract. In two normal hearts the tract then faded out in the central fibrous body. In one heart with Fallot's tetralogy it disappeared on the crest of the trabecular septum. Although we are unaware of any functional significance of these tracts, our findings are of considerable interest in understanding the development of the atrioventricular conduction system.     

A communication from the left ventricle to the right atrium: a defect in the central fibrous body

An isolated defect in the membranous atrioventricular septum was found in a five-year-old girl who presented with a cystic lesion in the right atrium. This type of left ventricular-right atrial communication could result from a structural abnormality of the central fibrous body in combination with arrested maturation of the membranous ventricular septum.     

Dysplasia of the atrioventricular valves associated with conduction system anomalies.

Clinical, vectorcardiographic, and echocardiographic data from two siblings with atrial septal defects and dysplasia of the mitral and tricuspid valves are reported. Vectorcardiograms showed that both siblings had abnormal ventricular activation with initial electrical forces directed posteriorly. One sibling died after surgery, and necropsy showed incomplete differentiation of the leaflets and tensor apparatus producing anomalies resembling "mitral arcade." Serial histological examination of the conducting tissue showed that the atrioventricular node was located on the left side of the atrial septum, that the central fibrous body and the membranous septum were hypoplastic, and that an accessory nodoventricular pathway originating in the compact node joined the left side of the ventricular septum. This accessory pathway was probably the cause of the unusual ventricular activation. Dysplasia of the mitral and tricuspid valves together with hypoplasia of the central fibrous body and the presence of accessory pathways are probably part of a malformative complex caused by incomplete differentiation of both the cardiac atrioventricular valves and the junctional area.     

Cardiac specialized tissue in hearts with an apparently single ventricular chamber (double inlet left ventricle)

The morphologic and histologie findings in 14 univerrtricular hearts are described. All hearts had a single ventricle with a main chamber receiving both atrioventricular orifices and giving rise to the posterior great vessel. The anterior great vessel arose from a smaller outlet chamber.The main finding was a grossly abnormal situation of the cardiac specialized tissue. Thus, in all 14 hearts the atrioventricular node was a small hypoplastic structure in the interatrlal septum. Connection between the atria and ventricles was made by way of an anterior node situated at the junction of the right atrial appendage with the anterior interatrial septum. From this node an atrioventricular bundle descended in the outflow tract of the posterior vessel and lay on the right margin of the foramen between the main and outlet chambers. The bundle was found in this position in both dextro- and levo-bulboventricular loops. The bundle bifurcated astride the septum between the chambers, and a typical left bundle branch passed into the main chamber. Right bundle branch tissue was always present in the outlet chamber. In two hearts with complete heart block neither node made contact with ventricular myocardium, but specialized tissue was present in the ventricular subendocardium.Because these findings have significance for surgical treatment, it is important to distinguish such hearts from “common” ventricles in which the specialized tissue is reported to lie in the posterior position. The mode of development of the abnormal tissue is discussed, with particular reference to the presence of anterior nodal tissue in normal human development. Finally, it is concluded that either of two concepts could account for the morphogenesis of the anomaly and that further studies are necessary to determine the correct hypothesis.     

Morphology of the region of the coronary sinus in respect to coronary sinus rhythm

The arterial supply to the region of the coronary sinus and the interatrial septum was examined in 18 normal canine hearts. In 13 of a further 18 dogs, coronary sinus rhythm was evoked by the ligation of atrial arteries, subsequent to which the arteries were visualized by injection of latex. A stable coronary sinus rhythm is evoked by producing ischaemia in an extensive area of the right atrium, including the sinus node, the interatrial septum and Bachmann's bundle, but preserving from ischaemia the posteroinferior part of the right atrium. Microscopical examination of the hearts with coronary sinus rhythm, and comparison with 9 control hearts, failed to demonstrate any morphological centre, in the form of nodal cells, which might have been responsible for the abnormal rhythm. In the posterior part of the right atrium, the ischaemic changes failed to affect the approaches of the atrioventricular node. The approaches were predominantly composed of cells poor in myofibrils mixed to a variable degree with cells of the working myocardium. We discuss the possibilities of the development of coronary sinus rhythm and "circus movement" with regard to the participation of the approaches to the atrioventricular node.     

The infundibular interrelationships and the ventriculoarterial connection in double outlet right ventricle. Clinical and surgical implications.

Fifty specimens of double outlet right ventricle were studied. The insertion of the outlet (infundibular) septum determines two types of infundibular interrelationships. In the first type, with anterior and posterior infundibulums, the outlet septum is inserted to the anterior limb of the septomarginal trabeculation; the posterior infundibulum is related with the atrioventricular orifices and the interventricular septum forms exclusively one of the walls of the posterior infundibulum. Therefore, the artery connected with the posterior infundibulum may be related with a subarterial ventricular septal defect. Of our material, 35 cases (70% of 50) had anterior and posterior infundibulums and, in 32, the aorta was connected with the posterior infundibulum (91.4% of 35). The ventricular septal defect was subaortic in 26 cases (81.2% of 32). In the second type, with side-by-side infundibulums, the outlet septum is inserted in to the ventriculo-infundibular fold in the proximity of the posterior limb of the septomarginal trabeculation. Both infundibulums are related with the atrioventricular orifices and the interventricular septum forms exclusively one of the walls of the medial infundibulum. Therefore, the artery connected with the medial infundibulum has the possibility of being related with a subarterial ventricular septal defect. Of our material, 13 cases (26% of 50) had side-by-side infundibulums. In all of these (100% of 13), the pulmonary trunk was connected with the medial infundibulum and the ventricular septal defect was subpulmonary in 12 cases (92.3% of 13). There were two cases (4% of 50) with a doubly committed ventricular septal defect. The insertion of the outlet septum permits one to determine the infundibular interrelationships, information which cannot be attained by taking into account the relationship of the great arteries with each other. Once the infundibular interrelationship is established, one must determine if the aorta is connected with the posterior or with the medial infundibulum, since, depending on the anatomical constitution of these infundibulums, there is the possibility of a ventricular septal defect being related with this artery. This information is indispensable before attempting the surgical correction of the double outlet right ventricle and it may be obtained by echocardiography or by angiocardiography.