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。     

文摘

０３７　二尖瓣脱垂与呼吸器官疾病［俄］／КорытниковКИ…／／КлинМед．－１９９９,７７（４）．－１５～１８由于心瓣膜和腱索粘液变性引起的二尖瓣和其他瓣膜脱垂,是系统性结缔组织衰弱的表现,可见于Ｍａｒｆａｎ综合征、Ｄａｎｌｏｓ综合征。作者观察９例心瓣膜粘液变性引起的二尖瓣脱垂病人,男７例,女２例;年龄５１～８２岁,平均６８－１岁。经超声心动图、心电图和胸部Ｘ线检查确诊。①单独二尖瓣脱垂１例,有Ⅳ度二尖瓣血流返流和Ⅲ度三尖瓣返流。②二尖瓣、三尖瓣脱垂５例：二尖瓣返流Ⅳ度１例,Ⅲ度３…     

左心疾病继发功能性三尖瓣返流的外科治疗现状

<正>健康人群中,约有80%~90%存有不同程度的三尖瓣返流[1]。功能性三尖瓣返流(functional tricuspid regurgitation,FTR)是指在无器质性三尖瓣病变及相关心肌损伤的情况下,由于三尖瓣及其相关结构的功能异常所导致的三尖瓣返流,常由左心系统瓣膜病变引起,是三尖瓣最常见的疾病。文献报道,至少1/3的二尖瓣病变患者存在中、重度三尖瓣返流[2],在实施二     

人工心脏瓣膜返流量的非定常流测量方法研究

为简化人工心脏瓣膜返流量测量装置的结构，降低测试成本，提出了用非定常流等效定常流进行人工心脏瓣膜返流量测量的新方法，推导出了非定常流等效定常流测量时的水头适用条件，利用流体力学拉格朗日积分建立了非定常流的非线性微分方程并进行了数值解析，分析了该方法的理论测量误差。计算和实验表明：在满足水头适用条件且瓣膜反向过流面积与测试管截面积比值小于3．422％时，非定常流测量方法实际测量精度可保证在2．27％以内。该方法的提出对于以非定常流等效定常流方法进行人工心脏瓣膜返流量测量系统的设计提供了理论依据。     

微创介入瓣膜治疗器械——瓣膜夹合器

正心脏二尖瓣反流是最常见的心脏瓣膜疾病,严重二尖瓣反流会引起左室扩大,最终导致左心衰竭、房颤和肺动脉高压。对于二尖瓣反流,药物治疗只能改善患者症状,而且不能延长患者生存或手术时机。虽说外科手术瓣膜修复或置换术被认为是二尖瓣反流疾病的标准治疗方法,但因需要体外循环,手术创伤大,一些高危患者不能耐受,术后恢复时间长。因而研发微创、低风险、治疗二尖瓣反流的介入治疗器械已成为国内外心血管器械研发的重点方向之一。     

经导管瓣膜瓣中瓣模式下流体力学性能体外测试及评价

目的 随着生物瓣膜毁损病例的增加,越来越多的经导管瓣膜作为瓣中瓣被应用于二次瓣膜置换手术,但其流体力学性能鲜有报道.本文将经导管瓣膜安装在生物瓣膜内形成瓣中瓣结构,并对其流体力学性能进行体外测试及评价.方法 将经导管瓣膜(23 mm、27 mm、29 mm)分别安装在对应规格生物瓣膜(23 mm、27 mm、29 mm)中形成瓣中瓣,进行稳态前向流实验、稳态反向泄漏实验、脉动流实验,对其流体力学性能进行评价,并与同规格生物瓣膜流体力学性能进行对比.结果 稳态前向流实验中,同一规格的经导管瓣中瓣跨瓣压差随着前向流量的增大而增大.稳态反向泄漏实验中,同一规格的经导管瓣中瓣泄漏量随着反向压力的增大而增大.脉动流实验中,经导管瓣中瓣和生物瓣膜的平均跨瓣压差、返流百分比和有效瓣口面积变化趋势相同.对于同一规格的经导管瓣中瓣和生物瓣膜,随着心输出量的增加,跨瓣压差增大,返流百分比减小,有效瓣口面积增大;在同一心输出量下,随着经导管瓣中瓣和生物瓣膜规格的增大,跨瓣压差减小,返流百分比增大,有效瓣口面积增大.结论 经导管瓣中瓣体外脉动流性能指标满足YY/T1449.3—2016标准中经导管瓣膜的性能要求,且其脉动流性能与同规格生物瓣膜相比无明显差异.该经导管瓣中瓣具有良好的血流动力学性能.     

一种新型介入瓣膜脉动流性能的初步研究

本文对一种国产新型介入瓣膜(HVPMIT)的体外脉动流性能进行了初步评价,并就该方法对HVPMIT的适用性进行了初步探索。试验中以国产HVPMIT为试验样品、进口的常规生物瓣为对照样品,根据ISO5840-2005和GB 12279-2008标准列出的方法,采用人工心脏瓣膜脉动流测试仪测定了试样的脉动流参数(包括平均跨瓣压差、返流百分比和有效开口面积)。结果显示,在模拟心输出量为5L/min时,HVPMIT的返流百分比高达13%,显著高于对照瓣,显示其发生了瓣周漏。进一步分析可以发现因为HVPMIT在植入体内时不需缝合,因此在HVPMIT支架外侧没有缝合环。当将HVPMIT夹持在试验仪器上时夹持垫片和HVPMIT支架间有明显缝隙,所以导致瓣周漏的发生。这说明,HVPMIT在外形、结构、在心脏上的固定方式、临床的手术方法等方面和传统的心脏瓣膜有明显的区别。必须根据其自身的特点,设计和建立适用的检测方法来科学客观地评价HVPMIT的性能。     

经食道三维超声在房颤二尖瓣结构变化对其 返流程度影响中的应用

目的 经食道三维超声心动图研究房颤患者二尖瓣结构变化对其返流程度影响。方法 选取电生理检查、射频消融手术患者66例。根据术前心电图分为阵发性房颤、持续性房颤、非房颤对照三组,分别行经胸二维超声检查,获得左房舒张末内径、左室舒张末内径、二尖瓣返流量,除外心脏瓣膜病、左心室扩大相关疾病、先心等病例。根据二尖瓣返流程度将其分为轻微返流、轻度返流、中度返流三组。行食道三维超声检查,应用MVQ软件进行二尖瓣量化分析,分别获得瓣环前后径、瓣环前外-后内径、瓣环高度、瓣叶非平面交角、前叶交角、后叶交角等二尖瓣参数。结果 对照组与持续性房颤组,对照组与阵发性房颤组之间DAIPm、H对比,差异有统计学意义（P＜0.05）;DAIPm、H在阵发性房颤组与持续性房颤组,差异无统计学意义（P＞0.05）;NAP、θANT、θPOST在持续性房颤、阵发性房颤、对照组,差异无统计学意义（P＞0.05）;DAP、DAIPm 在MR轻微组与中度组间比较,差异有统计学意义（P＜0.05）; H、θNAP、θANT在不同程度MR,差异无统计学意义（P＞0.05）;θPOST不同程度MR间对比,差异有统计学意义（P＜0.05）。结论 房颤患者二尖瓣后叶交角的增大常预示其功能性二尖瓣返流的增加,二尖瓣后叶交角对评估其反流程度有一定意义。     

32例心内膜垫缺损的外科治疗

目的 讨论和总结心内膜垫缺损外科治疗的方法和安全性。方法 分析全组32例心内膜垫缺损病人的手术方法和诊疗过程。重点讨论了瓣叶裂和房室间隔缺损的修补，房室瓣返流的纠正和防止传导束的损伤。结果 25病人心功能恢复到Ⅰ级，6例Ⅱ级。12例病人术后二尖瓣轻度返流，4例三尖瓣轻度返流，1例二尖瓣中重度返流。早期1例Ⅲ度房室传导阻滞，术后心率维持在50次/分左右（未用起搏器时），出院后2年随访心率没有明显改善，病人心功能Ⅱ级。全组死亡1例，原因为术后持续的低心排，于术后第三天救治无效死亡。结论心内膜垫缺损外科治疗效果满意，手术关键是防止传导束的损伤和术后补片残余漏，以及二尖瓣返流的纠正效果。术者的细心和经验是手术成功的关键。     

血泵瓣膜的现在与将来

现有许多瓣膜可适用于血泵—心室辅助泵或全人工心脏。难以置信的是人们仍然不停地制造出新的和改进后的瓣膜。在犹他人工心脏和心室辅助方案中,最近也使用了Medtroalc Hall瓣膜(Medtronic,Minneapolis,MN,USA)。该瓣膜有一块热解碳圆碟,这块热解碳圆碟悬挂在一块钛支持结构中,并可自由倾斜,此支持结构被机械地固定于心室的瓣膜支撑系统或连接系统上。许多年以前就选择了这种机械倾斜圆碟瓣膜作为较好的瓣膜,并在实验装置中不断地应用。很显然,这种瓣膜需要一些量的返流血液来关闭倾斜的圆碟,同时瓣膜关闭后,仍有血液返流。这种负向流动(即返流)降低了血泵效能。然而,当采用外动力体系和由压缩空气推动控制时,这种效能的丢失是能被接受的。     

A comparison of different feature extraction methods for diagnosis of valvular heart diseases using PCG signals

This article presents a novel method for diagnosis of valvular heart disease (VHD) based on phonocardiography (PCG) signals. Application of the pattern classification and feature selection and reduction methods in analysing normal and pathological heart sound was investigated. After signal preprocessing using independent component analysis (ICA), 32 features are extracted. Those include carefully selected linear and nonlinear time domain, wavelet and entropy features. By examining different feature selection and feature reduction methods such as principal component analysis (PCA), genetic algorithms (GA), genetic programming (GP) and generalized discriminant analysis (GDA), the four most informative features are extracted. Furthermore, support vector machines (SVM) and neural network classifiers are compared for diagnosis of pathological heart sounds. Three valvular heart diseases are considered: aortic stenosis (AS), mitral stenosis (MS) and mitral regurgitation (MR). An overall accuracy of 99.47% was achieved by proposed algorithm.     

Implications of third heart sounds in patients with valvular heart disease. The Veterans Affairs Cooperative Study on Valvular Heart Disease.

BACKGROUND. The presence of third heart sounds in patients with valvular heart disease is often regarded as a sign of heart failure, but it may also depend on the type of valvular disease. METHODS. We assessed the prevalence of third heart sounds and the relation between third heart sounds and cardiac function in 1281 patients with six types of valvular heart disease. RESULTS. The prevalence of third heart sounds was higher in patients with mitral regurgitation (46 percent) or aortic regurgitation (28 percent) than in those with aortic stenosis (11 percent) or mitral stenosis (8 percent). The left ventricular ejection fraction was significantly lower (P less than 0.001) when a third heart sound was detected in patients with aortic stenosis (0.38, vs. 0.56 in those without third heart sounds) or mixed aortic valve disease (0.40 vs. 0.55). However, the ejection fraction was only slightly lower in patients with mitral regurgitation and third heart sounds (0.51 vs. 0.57, P = 0.03). The pulmonary-capillary wedge pressure was higher (P less than 0.001) when a third heart sound was detected in patients with aortic stenosis (18.6 mm Hg, vs. 12.1 mm Hg in those without third heart sounds). There was no association between the wedge pressure and third heart sounds in patients with mitral regurgitation. The prevalence of third heart sounds increased with the severity of mitral regurgitation. CONCLUSIONS. In patients with mitral regurgitation, third heart sounds are common but do not necessarily reflect left ventricular systolic dysfunction or increased filling pressure. In patients with aortic stenosis, third heart sounds are uncommon but usually indicate the presence of systolic dysfunction and elevated filling pressure.     

Valvulopathy in primary antiphospholipid syndrome. Prospective echocardiography study

Echocardiographic studies have demonstrated a high prevalence of valvular disease in patients with primary antiphospholipid syndrome (PAPS). However, there are no studies assessing changes over time in valvular abnormalities. We conducted a study to determine whether there are changes over time in valvular lesions as detected by serial transesophageal echocardiography (TEE). Twelve patients with a first TEE had a second evaluation after a mean period of 13.5 months. There were 10 women and two men with a mean age of 38 years. Two patients had normal TEE on both initial and follow-up studies. Ten patients (83%) had valvular abnormalities, predominantly of the mitral and aortic valves in both studies. Abnormalities consisted of thickening, nodules, regurgitation, regurgitation and stenosis, and calcification. The type and frequency of lesions changed over time. As an example, one mitral valve nodule disappeared on follow up but three new aortic nodules developed even though all patients were receiving anticoagulant therapy. Two patients with mitral and aortic nodules presented cerebral ischemia. Mitral valvuloplasty was performed in one case. These results show that valvular abnormalities in patients with PAPS resolve, appear, or persist irrespective of anticoagulant therapy. Regurgitation is often mild or moderate, but stenosis may appear.     

Computer simulation of human mitral valve mechanics and motion

The human mitral valve is the left atrio-ventricular valve which is composed of several components including leaflets, chordae tendineae, papillary muscles, and the valve annulus. Any or all of these components may fail and contribute to various valvular diseases including mitral regurgitation and mitral valve prolapse. A computer simulation of mitral valve mechanics and motion was written in BASIC for micro-computers. This program allows valvular geometry and biomechanical parameters to be varied and records time varying motion of the valve and all components during systole including a graphic display of the valve leaflets.     

Computational analysis of the effect of mitral and aortic regurgitation on the function of ventricular assist devices using 3D cardiac electromechanical model

Valvular insufficiency affects cardiac responses and the pumping efficacy of left ventricular assist devices (LVADs) when patients undergo LVAD therapy. Knowledge of the effect of valvular regurgitation on the function of LVADs is important when treating heart failure patients. The goal of this study was to examine the effect of valvular regurgitation on the ventricular mechanics of a heart under LVAD treatment and the pumping efficacy of an LVAD using a computational model of the cardiovascular system. For this purpose, a 3D electromechanical model of failing ventricles in a human heart was coupled with a lumped-parameter model of valvular regurgitation and an LVAD-implanted vascular system. We used the computational model to predict cardiac responses with respect to the severity of valvular regurgitation in the presence of LVAD treatment. An LVAD could reduce left ventricle (LV) pressure (up to 34%) and end-diastolic ventricular volume (up to 80%) and maintain cardiac output at the estimated flow rate from the LVAD under the condition of mitral regurgitation (MR); however, the opposite would occur under the condition of aortic regurgitation (AR). Considering these physiological responses, we conclude that AR, and not MR, diminishes the pumping function of LVADs.     

Double valve disease in systemic lupus erythematosus. Case report and literature review

A young, nonhypertensive female with advanced systemic lupus erythematosus (SLE) presented in congestive cardiac failure due to aortic and mitral regurgitation. The valvular lesions resulted from organization of valvular pocket Libman-Sacks vegetations. Her clinical course mimicked infective endocarditis. She is only the third recorded patient with SLE valvular disease warranting double valve replacement. This patient, who had her valvular disease at presentation (prior to initiation of steroid therapy), illustrates that untreated SLE per se may produce severe organic valvular disease.     

Right-sided infective endocarditis combined with mitral involvement in a patient with ventricular septal defect

An autopsy case of right-sided infective endocarditis combined with mitral valvular involvement in a 20-year-old male Japanese with ventricular septal defect (VSD) was reported. The vegetations were found on the endocardium bordering VSD, tricuspid valve, mural endocardium of the right ventricular outflow tract, and even the pulmonic valve, resulting in forming infective aneurysm of the pulmonary trunk. Streptococcus was morphologically identified in the vegetations obtained at autopsy. On the other hand, smaller vegetations were also noted on the mitral valve. The mechanisms of the mitral extending were discussed when right-sided infective endocarditis associated with VSD preceded that on the mitral valve. The authors think that mitral regurgitation in relation to VSD and right to left shunt through VSD which occur even temporarily may be the most important mechanism responsible for the mitral valvular involvement. Several differences between right-sided and left-sided infective endocarditis were also reviewed.     

Die Doppler-echokardiographische Quantifizierung des regurgitierenden Blutvolumens bei Patienten mit Mitralinsuffizienz

Summary The purpose of this study was to assess the accuracy and clinical utility of pulsed Doppler echocardiography in determining the regurgitant fraction in patients with pure mitral regurgitation. In 30 unselected consecutive patients with mitral regurgitation and in 20 patients without valvular heart disease pulsed Doppler echocardiography was performed to measure blood flow at the mitral and aortic valve. The regurgitant blood volume was calculated as the difference of the stroke volumes measured at the mitral and aortic valve. The regurgitant fraction was computed as regurgitant blood volume/mitral flow. By cardiac catheterization regurgitant blood volume and regurgitant fraction were obtained from the left ventricular angiographic stroke volume and the stroke volume measured by thermodilution. Five patients were excluded because of technically poor left ventricular angiograms. In 4 patients with mitral regurgitation measurement of the regurgitant blood volume and regurgitant fraction was impossible by Doppler because of poor ultrasound signal quality. In 21 patients with mitral regurgitation the correlations between the invasive and the Doppler measurements were significant (regurgitant blood volume:r=0.89, SEE=20.9 ml; regurgitant fraction:r=0.91, SEE=7.1%). However, the mean percent error of the regurgitant fraction measurement (12.0±11.6%) was smaller than of the regurgitant blood volume measurement (24.9±17.0%). In the control group the regurgitant blood volume ranged between –25.1 ml and 11.6 ml and the regurgitant fraction between –17.7% and 12.4%.Thus, pulsed Doppler echocardiography is clinically useful in determination of the regurgitant fraction in 84% of unselected adult patients with pure mitral regurgitation. The Doppler method is limited in the diagnosis and quantification of mild regurgitation. However, the method is more accurate in determining the regurgitant fraction than measuring the regurgitant blood volume.

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Abkürzungsverzeichnis MI Mitralinsuffizienz - RBV regurgitierendes Blutvolumen - RF Regurgitationsfraktion - SV_Angio angiographisch berechnetes Schlagvolumen - SV_Ao Doppler-echokardiographisch an der Aortenklappe gemessenes Schlagvolumen - SV_Mi Doppler-echokardiographisch an der Mitralklappe gemessenes Schlagvolumen - SV_Thermo mittels Thermodilution bestimmtes Schlagvolumen     

RIGHT-SIDED INFECTIVE ENDOCARDITIS COMBINED WITH MITRAL INVOLVEMENT IN A PATIENT WITH VENTRICULAR SEPTAL DEFECT

An autopsy case of right-sided infective endocarditis combined with mitral valvular involvement in a 20-year-old male Japanese with ventricular septal defect (VSD) was reported. The vegetations were found on the endocardium bordering VSD, tricuspid valve, mural endocardium of the right ventricular outflow tract, and even the pulmonic valve, resulting in forming infective aneurysm of the pulmonary trunk. Streptococcus was morphologically identified in the vegetations obtained at autopsy. On the other hand, smaller vegetations were also noted on the mitral valve. The mechanisms of the mitral extending were discussed when right-sided infective endocarditis associated with VSD preceded that on the mitral valve. The authors think that mitral regurgitation in relation to VSD and right to left shunt through VSD which occur even temporarily may be the most important mechanism responsible for the mitral valvular involvement. Several differences between right-sided and left-sided infective endocarditis were also reviewed. ACTA PATHOL. JPN. 35 : 459–471, 1985