心房功能性二尖瓣反流的研究进展

心房功能性二尖瓣反流（AF-MR）是功能性二尖瓣反流的一种特殊类型,其发病率高,临床预后差。AF-MR的发病机制与二尖瓣瓣环扩张、房源性瓣叶牵拉、二尖瓣后叶运动障碍、二尖瓣瓣环收缩障碍、二尖瓣瓣叶适应性增生不足或过度增生、左室舒张功能不全及左房压升高有关。AF-MR患者临床上常合并高血压、糖尿病、长程持续性房颤、非二尖...     

二尖瓣复合装置的应用解剖学研究

本文从四个方面综述了近年来对二尖瓣复合装置的研究进展；（１）瓣膜（面积、厚度、结构、神经和淋巴等）；（２）腱索（分类、结构与瓣膜的关系）；（３）乳头肌；（４）纤维环，还提出有关二关瓣复合装置的一些有待于深入研究的问题。     

应用经食管实时三维超声评价缺血性二尖瓣反流及瓣叶形态功能变化的研究

目的应用经食管实时三维超声(RT-3D-TEE)和二尖瓣立体结构定量(MVQ)分析软件,对缺血性二尖瓣反流(IMR)的二尖瓣瓣环及瓣叶功能进行评价,筛选出对IMR机制有意义的参数。方法 25例IMR组患者,其中男性14例,女性11例;年龄41~72岁,平均年龄41.7岁。20例正常对照组,其中男性11例,女性9例;年龄37~69岁,平均年龄38.6岁。行RT-3D-TEE技术对2组患者进行检查,应用MVQ分析软件测量并分析2组二尖瓣瓣环及瓣叶几何形态学参数变化特点。结果 IMR组反流容积(46±11)m L,有限反流口面积(0.31±0.12)cm2,说明IMR组存在中度反流。与正常对照组相比,IMR组反映二尖瓣瓣环解剖结构参数如瓣环前外侧交界到后内侧交界的距离(DAIPm)、前叶瓣环中点到后叶瓣环中点的距离(DAP)、瓣环三维周长(C3DE)、绕环最小表面面积(A3Dmin)、环的椭圆度(E2D)及二尖瓣帆状区容积(Vtent)均有所增加(P﹤0.05);瓣环最高点所在平面与最低点所在平面的高(H)、环高度与联合直径的比率(H/DAIPm)、前后瓣叶对合的参数投影平面中的结合长度(L2DAIPm)及前后叶关闭时对合线的长度(LC3DLf)均有所减低(P﹤0.05)。与正常对照组相比,IMR组前小叶角度(θant)、后小叶角度(θpost)及小叶非平面角度(θnpa)未见明显变化。结论通过RT-3D-TEE能够为缺血性二尖瓣反流患者提供局部二尖瓣瓣环功能或形态异常的量化指标,为临床医生选择个性化治疗方案和疗效评价提供了依据。     

rh-BNP对扩张性心肌病伴重度二尖瓣反流患者行二尖瓣置换术血流动力学影响

目的：观察持续静脉应用重组人脑利钠肽(recombinant human brain natriuretic peptide,rh-BNP)对扩张性心肌病伴重度二尖瓣反流患者行二尖瓣置换术围术期血流动力学的影响。方法：在2012年1月至2016年06月期间,对扩张性心肌病伴重度二尖瓣反流行二尖瓣置换术的患者随机分组,其中对照组32例,rh-BNP组33例。对照组实施常规治疗,rh-BNP组在常规治疗基础上加用rh-BNP。观察比较两组患者围术期肺毛细血管楔压(pulmonary capillary wedge pressure,PCWP)、心脏排血指数(cardiac index,CI)、左心室射血分数(left ventricular ejection fraction,LVEF)、左心室短轴缩短率(left ventricular fractional shortening,LVFS)及左心室舒张末期内径(left ventricular end diastolic dimension,LVDd)。结果：与术前相比,两组术后均表现为PCWP降低,CI升高,比较有显著性差异(P<0.05),而LVEF、LVFS、LVDd无明显变化(P>0.05)。与对照组相比,rh-BNP组患者术后PCWP明显降低,CI明显升高,比较有显著性差异(P<0.05),而LVEF、LVFS、LVDd变化亦无显著性差异(P>0.05)。结论：在扩张性心肌病伴重度二尖瓣反流行二尖瓣置换术的患者中,rh-BNP能够降低PCWP,提高CI,从而改善围术期的血流动力学。     

房颤合并功能性二尖瓣返流研究

随着人口老龄化的加剧,功能性二尖瓣返流的发病率越来越高,已经成为最常见的瓣膜性疾病之一。而目前发现房颤患者往往合并二尖瓣返流,称为心房功能性二尖瓣返流,该类患者恢复窦性心律后二尖瓣返流症状往往会得到改善。但房颤与二尖瓣返流之间的关系尚不清楚,也缺乏房颤合并功能性二尖瓣返流患者治疗方案的相关指南推荐。本文就房颤与功能性二尖瓣返之间的联系、相关的评估和治疗方案进行综述。     

利用Contourlet变换进行双源CT图像中的二尖瓣分割

目的 利用双源CT图像对心脏二尖瓣瓣膜进行了增强与分割,为日后进行二尖瓣三维重建和运动分析提供基础。方法 提出了自适应种子填充法和Contourlet小波变换分别用于不同情况下的分割：首先用自适应种子填充法对双源CT胸腔图像进行心脏在造影剂下的区域分割,再用Contourlet小波变换对区域分割后的图像进行二尖瓣的增强和分割。结果 在MATLAB7.0的环境下对双源CT图像成功进行了处理和分割,获取了清晰的心脏二尖瓣图像。结论 本文提出的分割方法对不同情况下的分割非常有效,实验的结论对医生从事二尖瓣瓣膜运动研究和二尖瓣瓣膜外科手术规划提供有益的参考。     

双源CT诊断先天性冠状动脉畸形的研究

目的探讨双源CT(DSCT)对先天性冠状动脉畸形(CCA)的诊断价值及临床意义。方法对我院DSCT冠状动脉成像资料进行回顾性统计,对其中冠状动脉畸形病例进行统计分析,探讨临床应用价值。结果 1824例冠状动脉成像中检出CCA共43例(2.36%),其中冠状动脉起源异常24例(1.32%),冠状动脉走行异常18例,均为心肌桥,占CCA总数的41.9%,占总例数的0.99%。冠状动脉起源异常中右冠状动脉起源于左冠状窦9例,左冠状动脉起源于右冠状窦仅1例。结论 DSCT能够准确地显示冠状动脉畸形,特别是对心肌桥的敏感性高于其他检查方法,对临床诊断和预后评估有重要的应用价值,特别适用于门诊冠脉疾病的"一站式"检查。     

双源CT冠脉成像对冠状动脉畸形的诊断价值

目的：探讨双源CT（DSCT）冠脉成像在冠状动脉畸形（CAA）诊断中的价值。方法：回顾分析357例经DSCT冠脉成像检出的冠状动脉畸形患者的MPR、VR、MIP及CPR图像,其中31例患者的图像与常规冠状动脉血管造影（CAG）进行对照。结果：DSCT冠脉成像检出的357例冠状动脉畸形中,冠状动脉起源异常37例,包括冠状动脉高位起源15例,冠状动脉起源于对侧冠状窦13例,回旋支起自左冠状窦7例,回旋支起自右冠状窦1例,单一冠状动脉1例;本组冠状动脉走行异常均表现为心肌桥（MB）,其发现MB319例326处;冠状动脉终止异常中冠状动脉瘘1例。其中31例于DSCT冠脉造影后行CAG检查,DSCT冠脉成像检出27例29处MB者CAG仅检出21例22处,但3例冠状动脉起源异常及1例冠状动脉瘘行CAG全部检出。结论：DSCT冠脉成像能清晰地显示各种冠状动脉畸形,为术前评估及预后判断提供重要信息,亦可作为随诊复查的可靠方法。     

双源 CT 冠状动脉三维分割算法的研究

本研究旨在从心脏双源 CT 数据中自动精确分割出冠状动脉。采用一种基于多尺度滤波和概率决策的血管自动分割算法。先基于多尺度 Hessian 矩阵增强图像中的管状结构,再利用最大后验概率基于灰度将体素分为目标和背景2类,最后用26邻域区域生长法分割出左冠状动脉。实验结果表明,可精确分割出冠状动脉并提取血管中心线。该算法避免了血管泄露问题,无伪血管,无需人工交互,是一种有效的双源 CT 冠状动脉自动提取方法。     

新型国产二尖瓣夹合器系统的动物实验研究

通过动物实验,对一种新型国产二尖瓣夹合器系统的可行性和安全性进行评价。14只正常三元杂交系猪分为实验组10只和对照组4只,实验组植入新型二尖瓣夹合器系统,对照组行传统二尖瓣修复术。分别于术前、术后不同时间点行超声心动图检查、血液检查,术后140 d对动物安乐死取材,进行心脏及主要脏器大体、病理检查,观察植入后的情况。实验组共8只动物、对照组共4只动物达到实验终点,所有动物术中未出现夹合器脱落、心脏破裂、瓣膜损伤、顽固性心律失常、脏器栓塞、心力衰竭、死亡等严重并发症。超声显示,所有夹合器均固定在二尖瓣处,不同时间点二尖瓣平均跨瓣压差、左心室射血分数等两组间均未见具有统计学意义的差异。血液学检查,未见植入器械对肝肾功能产生明显影响。病理检查提示,夹合器周围瓣叶呈现慢性炎症、黏液样变性、少量出血,未引起二尖瓣及心脏组织损伤,未出现心脏血栓、感染,各脏器也未见血栓栓塞。动物实验结果表明,新型国产二尖瓣夹合器系统生物相容性好,能够有效固定在二尖瓣处而不引起严重的相关并发症。     

双源CT测量贵州小型猪活体肾解剖指标的精准性

目的:探讨双源CT及其后处理软件测量贵州小型猪活体肾解剖学指标的精准性。方法:对雄性健康成年贵州小型猪肾行CT扫描及MRP、VR重建后,测量双肾前后径及左右径(横断位正中层面)、双肾长短径(冠状位最大面)及双肾体积(容积测量)的大小,并计算长短径比值。其后处死实验动物取出肾标本,分别测量离体肾标本的上述参数;比较两种方法所得数据并行统计处理。结果:双肾前后径、左右径、长径、短径及体积经CT后处理测量与离体标本所测各指标的比较,差异均无统计学意义,说明双肾前后径、左右径、长径、短径及体积经CT后处理测量与离体标本所测各指标的结果具有一致性。结论:CT及其后处理软件测量贵州小型猪活体肾的解剖学指标准确,所得数据为贵州小型猪解剖指标提供正常参考值。     

人工腱索移植和马鞍环环缩修复退行性二尖瓣关闭不全

背景：人工腱索移植是二尖瓣成形的难点,瓣环环缩也是二尖瓣成形术式中的关键步骤之一,而目前国内相关此类治疗方法的安全性、有效性和中期疗效的较大样本报道较少。目的：总结二尖瓣人工腱索移植和马鞍环环缩技术治疗退行性二尖瓣关闭不全的有效性和安全性。方法：2009年1月至2013年5月间解放军沈阳军区总医院心血管外科应用人工腱索移植和马鞍环环缩技术治疗退行性二尖瓣关闭不全患者85例。用Gore-Tex缝线作为人工腱索,马鞍环用SJM^TM刚性鞍形成形环。共行人工腱索移植41例、人工腱索移植+后叶楔形切除21例、人工腱索移植+后叶楔形切除+Sliding技术23例。均行人工瓣环环缩术。结果与结论：治疗后随访78例,随访率为 91.7%(78/85)。随访时间为6个月-4年。78例中,1例于治疗后13个月死于脑梗死,1例死于交通事故,余76例均存活。NYHA心功能分级Ⅰ级59例,Ⅱ级17例。复查心脏彩超示微量及以下反流67例,轻度反流9例。超声心动图显示左心房直径明显减少(P < 0.05或P < 0.01),左心室舒张末期内径明显减少(P < 0.05或P < 0.01),左心室收缩末期内径明显减少(P < 0.05或P < 0.01),反流速面积/左房面积明显减少(P < 0.05或P < 0.01),肺动脉平均压明显降低(P < 0.05或P < 0.01),射血分数明显增加(P < 0.05或P < 0.01)。未出现二尖瓣收缩期前向运动现象(SAM征)。并发症情况：治疗后出现窦性心动过缓12例,阵发性室上性心动过速25例。1例治疗前伴快-慢综合征患者,治疗后安装永久起搏器。1例治疗后1周出现延迟性心包填塞,经心包穿刺置管引流后治愈。无成形环断裂或撕脱、无溶血、左室流出道梗塞、人工腱索断裂或劈裂发生。无再次手术行瓣膜置换患者。结果可见二尖瓣人工腱索移植和马鞍环环缩治疗退行性二尖瓣关闭不全安全、有效,近中期疗效满意。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程全文链接：     

Left atrial mechanical functions in chronic primary mitral regurgitation patients: a velocity vector imaging-based study

Introduction

Assessment of the left atrium (LA) mechanical function provides further information on the level of cardiac compensation. We aimed to evaluate LA function using a strain imaging method: velocity vector imaging (VVI) in chronic primary mitral regurgitation (MR).

Material and methods

We recruited 48 patients with chronic, isolated, moderate to severe MR (54.70 ±15.35 years and 56% male) and 30 age- and sex-matched healthy controls (56.52 ±15.95 years and 56% male). The LA volumes during reservoir (RV), conduit (CV) and contractile phases (AV) were measured. Global strain (S), systolic strain rate (SRs), early diastolic (ESRd) and late diastolic strain rate (LSRd) were calculated.

Results

LA RV (50 ±18.7 to 37.9 ±5.9; p = 0.0001), CV (43.1 ±29 to 21 ±2.56; p = 0.0001), and AV (17.9 ±13.5 to 10.9 ±1.9; p = 0.006) were increased in MR patients. The LA reservoir phase strain was 16.2 ±8.1% in the MR group and 51.1 ±5.7% in the control group (p = 0.0001). The LA SRs (1.01 ±0.52 s^–1 for MR and 2.1 ±0.22 s^–1 for controls; p = 0.0001), LA ESRd (0.83 ±0.34 s^–1 for MR and 2.26 ±0.17 s^–1 for controls; p = 0.0001) and LA LSRd (0.76 ±0.24 s^–1 for MR and 2.2 ±0.26 s^–1 for controls; p = 0.0001) were impaired in MR patients.

Conclusions

The LA deformation indices may be used as adjunctive parameters to determine LA dysfunction in chronic primary MR.     

Analog simulation of aortic and of mitral regurgitation

By using an equivalent electronic circuit either mitral or aortic regurgitation was simulated. Simulation allowed not only a measurement of various pressures within the cardiovascular system and cardiac output, but also mitral and aortic flow.In normal conditions mitral and aortic flows were monophasic, anterograde. In valve regurgitation mitral and aortic flows were, as expected, biphasic.In mitral regurgitation, during systole and diastole the valve flow was retrograde and anterograde, respectively.In aortic regurgitation, during systole and diastole the valve flow was anterograde and retrograde, respectively.The magnitude of the regurgitant valve flow was measured by time-integration and compared to the net flow, i.e. cardiac output. Valve flow was determined not only by the magnitude of valve dysfunction, but also by the resistive/capacitive characteristics of the “falsely” attached regurgitant circuit. If the regurgitant valve flow was large enough, it in turn affected the function of the left ventricle.The present investigation suggests that many features observed in patients with mitral or aortic regurgitation can be qualitatively satisfactorily simulated. In some respects even quantitative simulation is possible. However, for simulation of chronic mitral or aortic regurgitation, in the analog electronic circuit additional adjustments—in capacitance of the left ventricle and pulmonary system—would be required.     

The genetics of mitral valve prolapse

Mitral valve prolapse (MVP) is a very common clinical condition that refers to a systolic billowing of one or both mitral valve leaflets into the left atrium. Improvements of echocardiographic techniques and new insights in mitral valve anatomy and physiology have rendered the diagnosis of this condition more accurate and reliable. MVP can be sporadic or familial, demonstrating autosomal dominant and X-linked inheritance. Three different loci on chromosomes 16, 11 and 13 have been found to be linked to MVP, but no specific gene has been described. Another locus on chromosome X was found to cosegregate with a rare form of MVP called 'X-linked myxomatous valvular dystrophy'. MVP is more frequent in patients with connective tissue disorders including Marfan syndrome, Ehlers-Danlos and osteogenesis imperfecta. The purpose of this review is to describe previous studies on the genetics and prevalence of MVP. The report warrants the need for further genetically based studies on this common, albeit not fully understood, clinical entity.     

外科手术治疗小儿动脉导管未闭合并中、重度二尖瓣返流的疗效观察

目的：观察外科手术治疗小儿动脉导管未闭(patent ductus arteriosus,PDA)合并中、重度功能性二尖瓣返流(mitral regurgitation,MR)的疗效。方法：回顾性分析2006年1月至2009年12月期间行外科手术治疗PDA合并MR的患者12例。分别于动脉导管结扎术后1周、3个月和1年复查心脏超声,观察左室内径、左室收缩功能及二尖瓣返流面积与左房面积之比(MR/LA)的变化。结果：12例术前诊断PDA合并中、重度MR患者均行动脉导管结扎术,术后均无残余分流。术后3月后心脏彩色多普勒测定左室舒张末期内径(LVEDD)、左室射血分数(LVEF)、左室短轴缩短率(FS)和MR/LA均较术前明显改善(P<0.05);LVEDD术后1年较术后3个月进一步降低(P<0.05)。结论：外科手术治疗中重度功能性MR的PDA安全、有效。     

Tumorous deformity of mitral valve leaflet after chordal rupture in a child

A case with tumorous deformity of the posterior mitral valve leaflet after spontaneous chordal rupture in a child is described. A partial rupture in the chordae tendineae of the posterior mitral leaflet was found by echocardiography in a 9-year-old Japanese boy. Tumorous bulging was gradually developed in the leaflet and was surgically excised 5 years later. Multiple nodular tumors were found on the atrial surface of the posterior mitral leaflet. Histological examination revealed that the tumorous bulging consisted of myxomatous materials in which collagen fibrils and very fine elastic fibers were distributed loosely and irregularly. Normal-looking endothelial cells covered the luminal surface of the bulging lesion. Vimentin-positive spindle-shaped mesenchymal cells were scattered in the bulge area. The labeling index of proliferating cell nuclear antigen (PCNA) in these cells was 29.3%. These spindle cells were positive for matrix metalloproteinase (MMP)-1 in the entire bulge area. The cells and matrix were positive for MMP-2 and tissue inhibitor of MMP (TIMP)-1 in the basal area of bulging, but were weakly positive or negative at the surface area. Reactivity for TIMP-2 in the cells in the bulge area was obviously weaker than that in the cells at the spongiosa of the anterior mitral leaflet, which was obtained from the patient at the valve replacement operation 9 months after the initial operation. These findings indicated that the tumorous deformity of the mitral valve was formed by the overgrowth of valve tissue under the stimulation of mitral regurgitation in this child, and the imbalance of MMP and TIMP might play an important role in the bulge formation.     

Effect of physiological overload on pregnancy in women with mitral regurgitation

OBJECTIVES:

to evaluate the structural and functional heart abnormalities in women with mitral regurgitation during pregnancy.

INTRODUCTION:

Women with mitral regurgitation progress well during pregnancy. However, the effects on the heart of the association between pregnancy and mitral regurgitation are not well established.

METHODS:

This is a case–control, longitudinal prospective study. Echocardiograms were performed in 18 women with mitral regurgitation at the 12th and 36th week of pregnancy and on the 45th day of the puerperium. Twelve age‐matched healthy and pregnant women were included as controls and underwent the same evaluation as the study group.

RESULTS:

Compared with controls, women with mitral regurgitation presented increased left cardiac chambers in all evaluations. Increasing left atrium during pregnancy occurred only in the mitral regurgitation group. At the end of the puerperium, women with mitral regurgitation showed persistent enlargement of the left atrium compared with the beginning of pregnancy (5.0 ± 1.1 cm vs 4.6 ± 0.9 cm; p<0.05). Reduced left ventricular relative wall thickness (0.13 ± 0.02 vs 0.16 ± 0.02; p<0.05) and an increased peak of afterload (278 ± 55 g/cm² vs 207 ± 28 g/cm²; p<0.05) was still observed on the 45th day after delivery in the mitral regurgitation group compared with controls.

CONCLUSIONS:

Pregnancy causes unfavorable structural alterations in women with mitral regurgitation that are associated with an aggravation of the hemodynamic overload.     

Computational simulations of mitral regurgitation quantification using the flow convergence method: Comparison of hemispheric and hemielliptic formulae

Mitral regurgitation results from the incomplete closure of the mitral valve, and the noninvasive diagnosis of this disease remains an important clinical goal. In this study, steady flow computer simulations were used to evaluate flow convergence method for flow rate estimation. The hemispheric and hemielliptic formulae were compared for accuracy in the presence of complicating factors such, as ventricular confinement, orifice shape, and aortic outflow. Results showed that in the absence of aortic outflow and ventricular confinement, there was a plateau zone where the hemispheric formula approximated the true flow rate, independent of orifice shape. However, in the presence of complicating factors such as aortic outflow and ventricular confinement, there was no clear zone where the hemispheric formula could be applied. The hemielliptic formula, however, worked in, all cases, regardless of chamber size or magnitude of aortic outflow. Therefore, application of the hemielliptic formula shold be considered in future clinical studies.