儿童心脏右房室瓣解剖类型调查

目的为临床儿童心脏右房室瓣病变的诊治提供解剖学资料。方法对135例出生1 d至15岁儿童心脏标本的右房室瓣主瓣和副瓣的形态进行观测。结果主瓣类型分为二尖型、三尖型、四尖型和五尖型。主瓣分为内瓣、前瓣、后瓣和外瓣、后内瓣、前外瓣和后外瓣。主瓣形状分为三角形、半椭圆形、半圆形、长方形和梯形。40例有副瓣,其中33例有两个副瓣,7例有1个副瓣。副瓣分为前内副瓣、后内副瓣、前外副瓣和后外副瓣。右房室环形状可分为椭圆形、圆形、三角形和肾形,其中椭圆形最多见。结论主瓣和副瓣都有明显位置,它们可以密闭心室与心房的交通,使血液不能逆流入心房。了解儿童右房室瓣的解剖类型可供手术时参考。     

成人右房室瓣乳头肌腱索支配的解剖类型调查

目前，国内外学者对成人心脏右房室瓣主瓣、副瓣支配其运动的乳头肌和腱索的数目多少见解不一，由于近十多年来心脏外科的迅速发展，为了进一步提供国人右房室瓣所支配的乳头肌及腱索的资料，以供临床参考，本文对国人心脏右房室瓣乳头肌腱索支配的解剖类型进行了调查。     

汉族成人心脏右房室瓣连合区解剖类型和临床意义

目的为临床心脏右房室瓣病变的诊治提供解剖学资料.方法对171例中国汉族成人心脏行右房室瓣主瓣连合区和主副瓣连合区的形态学观测. 结果主瓣连合区分为单主瓣和联合主瓣间连合区及单主瓣和单主瓣间连合区.主副瓣连合区分为单主瓣和副瓣间连合区及联合主瓣和副瓣间连合区.结论主瓣连合区和主副瓣连合区都有明确位置,它们可以密闭心室与心房的交通,使血液不能逆流入心房.在外科手术时,必须要注意它们的解剖分型.     

成人心脏右房室瓣解剖类型的观察

目的：为临床心脏右房室瓣病变的诊治提供解剖学资料。方法：对171例汉族成人心脏观测其主瓣和副瓣的形态和度量。结果：主瓣高13mm以上，附着缘16mm以上。主瓣分为单主瓣、双主瓣和联合瓣。副瓣高12mm以下，附着缘长11mm以下。副瓣分为前内副瓣、后内副瓣、前外副瓣和后外副瓣。结论：主瓣和副瓣都有明确位置，它们可以密闭心室与心房的交通，使血液不能逆流人心房。了解右房室瓣的解剖类型可供手术时参考。     

房室瓣骑跨的形态分析

对１０例先天性畸形心脏的房室瓣骑跨进行形态分析，其中７例为三尖瓣骑跨，２例为二尖瓣骑跨和１例为两侧室瓣骑跨，９例属完全性骑跨和１例属不完全性骑跨。除去瓣骑跨外，房室瓣还伴有瓣，降落伞形，囊状副瓣，异位乳头肌和异位腱索等畸形。     

肺动脉四瓣变异1例

作者在解剖一具2岁的男童标本时,发现其心脏肺动脉瓣异常,现报道如下:心脏的外形大小正常,肺动脉有4个瓣膜.按瓣膜位置分前半月瓣,左半月瓣,右半月瓣,其中前半月瓣分为两个大小对称的小半月瓣,前(左)瓣膜基底部长4.3 m m,深5.9 m m,厚0.3 m m,前(右)瓣膜基底部长4.8 m m,深5.6     

人体二尖瓣建模及生物力学分析

目的 建立人体心脏二尖瓣仿真模型,模拟二尖瓣闭合的工作过程,分析二尖瓣各组件应力分布,探讨二尖瓣瓣叶和腱索的相互作用,并探寻腱索受力大小与腱索粗细之间的相关性。方法 构建二尖瓣几何模型,在此基础上定义模型单元类型、材料属性、接触、载荷及约束,建立有限元模型,计算模型的应力、速度和位移等参数。结果 瓣膜上的应力分布不均匀,后瓣叶亚区之间的裂口位置所受应力最大;不考虑腱索连接至瓣叶时,瓣叶负载后外翻至心房一侧;考虑腱索连接至瓣叶时,前、后瓣叶关闭良好;各腱索受力不同,与前瓣叶相连的支持腱索受力最大,腱索受力大小与腱索粗细之间的线性相关系数为0.954。结论 瓣叶中心和后瓣叶亚区之间的裂口两处应力较大区域是临床上二尖瓣裂的常发生部位;与瓣叶相连的腱索可在瓣叶负载时,施加牵拉力使瓣叶不致发生翻转,前、后瓣叶恰好关闭;解剖结构粗壮的腱索受力较大。     

室间隔膜部的应用解剖学研究

目的阐明成年人心室间隔膜部的形态、位置、毗邻关系,为医学影像诊断提供形态学基础。方法成年人离体心脏64例,大体解剖观察室间隔膜部的形态、位置、毗邻结构。胸部断层标本观察室间隔膜部的原位解剖学特征。结果离体心室间隔膜部:①形态可见不规则形、三角形、半月形、圆形、卵圆形、四边形和楔形。②左侧面位于主动脉前半月瓣环和右后半月瓣环相对缘与肌性室间隔嵴之间,上缘紧邻主动脉前半月瓣环和右后半月瓣环及其瓣间三角;右侧面位于三尖瓣前内侧连合处,房室隔最前端,与三尖瓣前内侧连合、室上嵴、主动脉隆凸、Koch三角尖端和右纤维三角相邻。经四心腔横断层,MPIS占室间隔的后1/3,自左前斜向右后与矢状面、冠状面约呈45°角;经升主动脉冠状断层,MPIS自肌性室间隔嵴斜向右上方达主动脉半月瓣环的下方,与正中矢状面呈45°角。结论MPIS形态多样,左、右侧面的位置和毗邻各异;横断层和冠状断层能很好地显示MPIS的形态、位置和毗邻关系。     

《外科和放射解剖学》杂志文题摘要(2002年第20卷第3期)

1 Anatomic study of the tricuspid valve in children Gerola LR,Wafae N, Vieira MC, Juliano Y, Smith R, Prates JC婴儿三尖瓣解剖学研究 对1岁以内婴儿防腐右房室瓣标本进行了解剖研究。主要研究瓣膜数目及形态学特征,如瓣底宽度、瓣尖高度同时涉及乳头肌数目、腱索数目、纤维环直径,并将纤维环分为前、后及隔区以定位瓣膜,结果显示瓣膜数目介于2～4个,3尖瓣类     

中国人心脏房室瓣的类型调查(100例)

本报告调查了100例成年中国人的死后固定的心脏标本。右房室瓣以四个主瓣为最常见,占80%。三个主瓣的占19%,只有两个主瓣的占1%。除主瓣外,在右心室内侧壁与前、后壁之间有时存在小的分裂瓣,可以称它们为“副瓣”。前副瓣出现率为31%,后副瓣为27%。若以主副瓣总数计算,则右房室瓣以四个瓣(42%)和五个瓣(36%)为最常见,其次为三个瓣(13%),六个瓣(8%)和二个瓣(1%)。左房室瓣由二个主瓣构成。但后瓣往往极度分裂,以致后瓣可由一个大瓣和一至四个小瓣所组成;仅有一个大瓣而没有分裂瓣的例子只占12%。我们将二尖瓣的后瓣归纳为三种类型:(1)后瓣的中部发育较好(48%);(2)后瓣的前外部发育较好(35%);(3)后瓣的后内部发育较好(17%)。前瓣分裂为二部的极少,只见一例(1%)。在调查同时,测量了各个瓣膜的高度及相邻瓣膜间的连接缘的高度。并讨论了区别主、副瓣的原则。     

False chordae tendineae in right ventricle of adult human hearts – morphological aspects

Introduction

False chordae tendineae are fibrous-muscular bundles which do not interconnect with right atrioventricular valves. The structures have occasionally been described in the right ventricle. There are reports suggesting their influence on electromechanical processes taking place in the heart, in thromboembolic events as well as in the course of cardiac invasive procedures. The objective of the study was to perform a macroscopic evaluation of false chordae tendineae in the right ventricle.

Material and methods

The research specimens consisted of 100 hearts of adult humans, aged from 18 to 59 years, fixed in a solution of 10% formaldehyde and 98% ethanol. The ratio of false chordae tendineae to individual elements of the right ventricle, such as its walls, papillary muscles, septomarginal trabecula and the apex of the ventricle, was examined.

Results

During examination, six types of chordae tendineae were described based on the criterion of the type of structures they connected. The most common were false chordae connecting ventricle walls within its apex, while the least common were individual segments of papillary muscles. The research proved that the examined structures are morphologically extremely diverse. Substantial clinical implications of their presence seem very probable.

Conclusions

The present work is the first of a scheduled series devoted to the problem of false chordae tendineae. Further analyses will cover the subject of morphological aspects in a microscopic perspective.     

Determination of the pressure required to cause mitral valve failure

A method has been developed for applying water pressure to a closed mitral valve on the side corresponding to the heart's left ventricle. The pressure is increased until fluid flows through the valve, i.e. until it fails. A specific dissection technique has been developed to produce a specimen with two annular rings, mitral annulus and papillary muscle annulus. Since the valve is maintained intact, with its leaflets attached to papillary muscles by the chordae tendineae, this method allows the effects of ruptured chordae and their surgical repair or replacement to be assessed in vitro. The chamber that holds the valve supports both the mitral annulus and papillary muscle annulus of the specimen. The mitral annulus is sutured onto rubber sheeting held in the chamber. The papillary muscle annulus is held in place by a Perspex support. The main part of the apparatus consists of a water pump connected through flexible tubing to the chamber that holds the valve in place. The pressure at failure is measured using a pressure transducer. Preliminary experiments demonstrate that anterior leaflet marginal chordae, but not strut chordae, are vital to valve function. Posterior leaflet chordae have been found to be important for valve competence.     

Morpho‐functional characterization of the heart of Gallus gallus domesticus with special reference to the right muscular atrioventricular valve

In this work, we studied the structure and function of the adult chicken heart with a focus on the right muscular atrioventricular valve using anatomic and echocardiographic methods. We demonstrated that the free wall thickness of the right and left ventricles changes from the apex to the base of the heart. The right muscular atrioventricular valve (RAVV) is joined directly to both the parietal right ventricle free wall (one attachment) and the interventricular septum (two attachments: ventral and dorsal). This valve does not have chordae tendineae or papillary muscles. The quantitative morphological and functional characterization of the RAVV is given. In color Doppler echo, no regurgitation of blood flow in the RAVV was observed in any of the studied birds. The blood flow velocity in the RAVV is 56.2 ± 9.6 cm s^‐1. A contractile function of the RAVV is shown. Based on the findings obtained, we conclude that the RAVV has a sufficient barrier function. In addition, as this valve is an integral part of the right ventricle free wall, it contributes to the right ventricle pump function. An agreed nomenclature of the parts of the RAVV is required.     

Distribution of PGP 9.5, TH, NPY, SP and CGRP immunoreactive nerves in the rat and guinea pig atrioventricular valves and chordae tendineae

The distribution of nerves immunoreactive to protein gene product 9.5 (PGP 9.5), tyrosine hydroxylase (TH), neuropeptide Y (NPY), substance P (SP) and calcitonin gene related peptide (CGRP) antisera was investigated in the atrioventricular valves of the Sprague–Dawley rat and the Dunkin–Hartley guinea pig using confocal and epifluorescence microscopy. No major differences were noted between the innervation of the mitral and tricuspid valves in either species. For all antisera the staining was more extensive in the guinea pig valves. Two distinct nerve plexuses separated by a ‘nearly nerve free’ zone were identified in both species with each antiserum tested. This was most apparent on the anterior cusp of the mitral valve. The major nerve plexus extends from the atrioventricular ring through the basal, intermediate and distal zones of the valves towards the free edge of the valve cusp. These nerve bundles, arranged as primary, secondary and tertiary components, ramify to the free edge of the valve and extend to the attachment of the chordae. They do not contribute to the innervation of the chordae tendineae. The second, minor chordal plexus, runs from the papillary muscles through the chordae tendineae and passes parallel to the free edge of the cusp. The nerves of this minor plexus are interchordal, branching to terminate mainly in the distal zone, free edge of the valve cusp and adjacent chordae tendineae. Some interchordal nerve fibres loop from a papillary muscle up through a chorda, along the free edge and pass down an adjacent chorda into another papillary muscle. The nerve fibres of the major and minor plexuses intermingle although no evidence was found for interconnectivity between them. In the distal zone between the major plexus which extends from the base of the valve and the minor chordal plexus there is a zone completely free of nerves staining with antisera to TH and NPY. Occasional nerves which stained positive for PGP 9.5, SP and CGRP immunoreactivities crossed this ‘nearly nerve free zone’ passing either from the chordal/free edge nerves to the intermediate and basal zones or vice versa. An additional small nerve plexus which displayed immunoreactivity to CGRP antiserum extended from the atrioventricular ring into the basal zone of the valve cusp. Not all chordae tendineae displayed immunoreactive nerve fibres. It is concluded that the innervation patterns of the sensory and sympathetic neurotransmitters and neuropeptides examined in the atrioventricular valves of the rat and guinea pig are ubiquitous in nature. The complexity of the terminal innervation network of the mammalian atrioventricular valves and chordae tendineae may contribute to the complex functioning of these valves in the cardiac cycle.     

Floppy mitral valve chordae tendineae: histopathologic alterations

Pathologic studies of floppy or myxomatous mitral valves have focused primarily on changes in the valve cusps, with little attention given to the chordae tendineae. In a systematic study of the histopathology of floppy mitral valve chordae tendineae, 128 nonruptured chordae from 8 severely regurgitant floppy mitral valves were compared to 152 chordae from 10 normal control mitral valves and to 152 chordae from 8 control mitral valves with severe regurgitation due to ischemic heart disease. Collagen alterations were observed in 2% of normal mitral valve chordae and 3% of control regurgitant mitral valve chordae compared to 38% of floppy mitral valve chordae. Moderate or severe acid mucopolysaccharide accumulation was observed in 2% of normal mitral valve chordae and 3% of control regurgitant mitral valve chordae compared to 39% of floppy mitral valve chordae. Nonuniform histopathologic alterations, rare in normal and control regurgitant mitral valve chordae tendineae, were frequent in floppy mitral valve chordae tendineae (p less than 0.001). Histopathologic alterations provide the basis for abnormal physical properties previously demonstrated in floppy mitral valve chordae tendineae and may predispose to chordal elongation and rupture.     

Design of heart valves: A review

Each of the major cardiac valves (two arterial and two atrioventricular) is made up of a fibrous annulus with a characteristic configuration, and cusps or leaflets comprising a layer of endocardium folded over a fibrous lamina. Each of the arterial valves (aortic and pulmonary) has an annulus shaped like a three-pronged coronet to which are attached three equal-sized semilunar cusps. The arterial wall beyond each cusp forms a pocket or sinus which is crucial in the efficient closure of these valves. The coronary arterial orifices in the aorta lie high in two of the sinuses or above them and are unaffected by valve action. Narrowing of the annulus is a significant component of closure of each cardiac valve, more so for the atrioventricular valves than the arterial. Despite their traditional terminology, the left and right atrioventricular valves (mitral and tricuspid) both possess more than three leaflets each. Closure of these valves is not dependent on the number of leaflets and it is easiest to regard leaflet tissue as a continuous veil or skirt tapering towards the ventricles, where it is tethered to papillary muscles by means of chordae tendineae. Closure of these valves is biphasic, an incomplete phase in late diastole and complete closure during ventricular systole. Movement of atrioventricular leaflet tissue is slight as it is held down by tension of the chordae tendineae. © 1993 Wiley-Liss, Inc.     

Papillary muscles and tendinous cords of the right ventricle of the human heart morphological characteristics

A series of 79 normal human hearts was studied focusing on the morphological characteristics of the papillary muscles of the right ventricle and their tendinous cords (chordae tendineae). The number, incidence, length and shape of the anterior, septal and posterior papillary muscles were observed. The tendinous cords attached to each papillary muscle were counted at their origin. The papillary muscles and the tendinous cords were measured in situ and after the removal of the right atrioventricular valve (tricuspid valve). The anterior and posterior papillary muscles (apm, ppm) were present in 100% of the cases. The septal papillary muscle (spm) was absent in 21.5% of the hearts. The apm presented 1 head in 81% and 2 heads in 19% it was 19.16 mm in length. The spm was one-headed in 41.7% and presented two heads in 16.5% the presence of a 3 and 4 heads appeared in 12.7% and 7.6% respectively the spm was 5.59 mm in length. The ppm had 1 head in 25.4%, 2 heads in 46.8%, 3 heads in 21.5% and 4 heads in 6.3% of the cases it was 11.53 mm in length. Tendinous cords (TC) varied as follows from 1 to 11 TC originated in the apm (mean 4.74) from 1 to 8 TC originated in the ppm (mean 2.67) and from 1 to 5 TC originated in the spm (mean 1.77).     

Morphogenesis of chordae tendineae. I: Scanning electron microscopy

The formation of the chordae tendineae of the left atrioventricular valve in the chick embryo is described using scanning electron microscopy. These supportive structures for the valve cusps develop between days 6 and 13 of incubation. Elevations which represent the primitive papillary muscles form on the ventricular wall. These elevations bifurcate into thin, weblike folds which are attached to the primitive valve cusps. The folds are the primordia of the chordae tendineae. Linear ridges develop on the web between the cusp and papillary muscle. These ridges alternate with depressions. The depressions become perforate to create the individual chorda from the linear ridges. Multiple perforations form initially but they typically consolidate to create one large aperture between two chordae. Some interchordal connections of tissue do persist throughout the period studied. During the period of perforation, prominent rounded cells are typical of the endocardium between the chordae. These cells are similar at the scanning electron microscope level to those present in the formation of the foramina secunda of the atrial septum. Primary, secondary, and tertiary chordae tendineae appear to develop in the same manner. First order chordae (those attached at the free margin of a cusp) are not found in the chick embryo. The majority of the chordae are second order, which insert into the ventricular surface of the cusp a short distance from the free edge. These chordae typically have a horizontal banding or grooving along their length. Third order chordae which extend from the papillary muscle to the ventricular wall are also present. It is suggested that chordal development is a programmed cellular and hemodynamic event.     

Normal distribution of melanocytes in the mouse heart

We report the consistent distribution of a population of pigmented trp-1-positive cells in several important septal and valvular structures of the normal mouse (C57BL/6) heart. The pigmented cell population was first apparent by E16.5 p.c. in the right atrial wall and extended into the atrium along the interatrial septum. By E17.5, these cells were found along the apical membranous interventricular septum near or below the surface of the endocardium. The most striking distribution of dark pigmented cells was found in the tricuspid and mitral valvular leaflets and chordae tendineae. The normal distribution of pigmented cells in the valvuloseptal apparatus of C57BL/6 adult heart suggests that a premelanocytic lineage may participate in the earlier morphogenesis of the valve leaflets and chordae tendineae. The origin of the premelanocyte lineage is currently unknown. The most likely candidate populations include the neural crest and the epicardially derived cells. The only cell type in the heart previously shown to form melanocytes is the neural crest. The presence of neural crest cells, but not melanocytes, in some of the regions we describe has been reported by others. However, previous reports have not shown a contribution of melanocytes or neural crest derivatives to the atrioventricular valve leaflets or chordae tendineae in mouse hearts. If these cells are of neural crest origin, it would suggest a possibly greater contribution and persistence of neural crest cells to the valvuloseptal apparatus than has been previously understood.