The significance of systolic anterior motion (SAM) on the mitral valve echo pattern in hypertrophic cardiomyopathy

The systolic anterior motion (SAM) of valve structures in the mitral echogram in hypertrophic cardiomyopathy (HCM) has previously been considered to be anterior motion and re-opening of mitral valve leaflets, causing left ventricular outflow tract (LVOT) obstruction and mitral regurgitation. Fifteen patients with HCM underwent cardiac catheterisation and were also examined by M-scan and mechanical real-time B-scan techniques. In all patients SAM was seen during M-scan echocardiography. The mitral valve leaflets were visualised during the entire cardiac cycle during real-time B-scanning without showing any re-opening in systole. Thickened papillary muscles have been observed in 12 patients and prominent chordae tendineae moving in the opposite direction to the anterior mitral valve leaflet in 10 patients. Four patients with SAM did not show mitral regurgitation during left ventricular angiography. In two patients without fixed haemodynamic obstruction, a complete SAM touching the interventricular septum was observed with prolonged apposition in one case. These findings suggest that SAM is due to the motion of chordae tendineae and/or papillary muscles traversing the single dimensional ultrasonic beam in systole, thus producing single linear or multiple spotty echoes within SAM. The mechanism of the upward motion of the subvalvular mitral valve apparatus in systole appears to be due to forceful contraction of the apical left ventricular posterior wall. The observation of SAM in patients without HCM also indicates that its presence during single dimensional echocardiography is neither diagnostic nor specific for HCM, LVOT obstruction or mitral regurgitation, and contradicts the assumption that the anterior mitral valve leaflet plays a significant role in the mechanism of LVOT obstruction. The salient feature of all conditions associated with abnormal mitral subvalvular motion is hyperkinetic contraction of the apical left ventricular posterior wall. Hyperkinetic left ventricular ejection appears to be the main factor in the complex development of an LVOT gradient in hypertrophic cardiomyopathy.     

保留瓣下结构的二尖瓣替换术后早期效果观察

目的：二尖瓣关闭不全患者行常规二尖瓣替换术后常有左心室功能恶化，有作者推测术中二尖瓣结构的破坏是导致术后左心室功能不全的主要原因之一。本文旨在探讨保留瓣下结构的影响。方法：总结了保留瓣下结构的二尖瓣替换术２６例，其中部分保留２２例为二尖瓣狭窄，完全保留４例为二尖瓣关闭不全。结果：与同期完全切除的２６例（均为二尖瓣狭窄）比较，保留瓣下结构者术后低心输出量综合征发生率较低，左心房缩小较明显，未发生左心室破裂。其余５项指标两组间无差异。结论：二尖瓣关闭不全者应完全保留瓣下结构，其中将人工瓣置入二尖瓣口内更为简便安全。部分二尖瓣狭窄者可保留后瓣及瓣下结构，而瓣叶和瓣下结构病变严重者则应完全切除。     

Double orifice mitral valve associated with endocardial cushion defect

Duplication of the mitral valve is a rare congenital cardiac anomaly. We encountered a case of duplication of the mitral valve associated with a partial form of endocardial cushion defect in a 6-year-old girl. The mitral orifice was separated by a fibrous tissue and each orifice provided papillary muscle and complete subvalvular mechanisms except for the cleft region. The fibrous tissue also provided a subvalvular apparatus. The cleft was repaired without complication. The short axis view of the two-dimensional echocardiogram demonstrated two separate holes in the mitral valve, which constituted the most obvious diagnostic sign prior to surgery.     

Mitral valve repair for ischemic mitral regurgitation: lessons from the Cardiothoracic Surgical Trials Network randomized study

Approximately 30% to 50% of patients will develop ischemic mitral regurgitation (MR) after a myocardial infarction, which is a result of progressive left ventricular remodeling and dysfunction of the subvalvular apparatus, and portends a poor long-term prognosis. Surgical treatment is centered on mitral valve repair utilizing a restrictive annuloplasty, or valve replacement with preservation of the subvalvular apparatus. In the recent Cardiothoracic Surgical Trials Network (CSTN) study, patients with severe ischemic MR were randomized to mitral valve repair with a restrictive annuloplasty versus chordal-sparing valve replacement, and concomitant coronary artery bypass grafting, if indicated. At 2-year follow-up, mitral valve repair was associated with a significantly higher incidence of moderate or greater recurrent MR and heart failure, with no difference in the indices of left ventricular reverse remodeling, as compared with valve replacement. The current appraisal aims to provide insight into the CSTN trial results, and discusses the evidence supporting a pathophysiologic-guided repair strategy incorporating combined annuloplasty and subvalvular repair techniques to optimize the outcomes of mitral valve repair in ischemic MR.     

Subvalvular left ventricular pseudoaneurysm: A rare complication of mitral valve replacement

A patient who developed a subvalvular left ventricular paeudoaneurysm following mitral valve replacement is presented, the fourth such case in the literature. The etiology of this uncommon complication is felt to be caused by excessive surgical resection of the diseased nitral valve, which may weaken or cause rupture of the heart at the mitral annulus. The diagnosis can only be made by left ventriculography. Surgical treatment is indicated, because rupture of the pseudoaneurysm can occur.     

Diagnosis of subvalvular adhesions in mitral stenosis by 2--dimensional echocardiography

Echocardiographic signs of subvalvular fusions are discussed, as they frequently complicate the course of mitral stenosis. The diagnostic value of two-dimensional echo-cardiography is established for this abnormality. Subvalvular fusions of the chordal apparatus are shown to be associated with certain signs on the two-dimensional echocardiogram, such as additional echoes under mitral valve cusps in short-axis heart section (sensitivity 67.2%, specificity 90.7%), and mitral orifice drawn towards the interventricular septum (sensitivity 35.7%, specificity 93.5%), thickened subvalvular structures in the long-axis section of the heart's left compartments (sensitivity 40.7%, specificity 82.9%), and fissural or "coma-like" shape of the mitral orifice.     

Value of two-dimensional echocardiography in selecting patients and balloon sizes for percutaneous balloon mitral valvuloplasty

The effect of valvular and subvalvular morphologic features and balloon size/mitral anulus size ratio on results of valvuloplasty were prospectively studied in 38 consecutive patients undergoing mitral valvuloplasty. The severity of valvular and subvalvular disease was graded echocardiographically from grade I to IV (mild to severe) for immobility, thickening, calcification of mitral leaflets and subvalvular thickening and fusion, yielding a maximal total score of 16. The diastolic mitral anulus diameter was measured in the apical four chamber view. After valvuloplasty, the mitral valve area increased from 0.9 +/- 0.3 to 2.2 +/- 0.5 cm2 (p less than 0.001) with increasing mitral regurgitation in 12 (32%) of the 38 patients. Multiple stepwise analysis revealed that the ratio of balloon size and annular size and the severity of subvalvular disease are two independent factors that correlated significantly with the mitral valve area after valvuloplasty (multiple r = 0.65, p less than 0.0002). One of 34 patients with mild subvalvular disease of grade III or less had an unsatisfactory increase in mitral valve area to less than or equal to 1.5 cm2, whereas 3 of 4 patients with severe (grade IV) subvalvular disease had a valve area less than or equal to 1.5 cm2 (p less than 0.002) after valvuloplasty. The increase in mitral regurgitation after valvuloplasty correlated significantly with the ratio of balloon to mitral anulus size and the severity of subvalvular disease (multiple r = 0.53, p less than 0.003). (ABSTRACT TRUNCATED AT 250 WORDS)     

Usefulness of echocardiography in the prediction of early results of catheter balloon mitral valvuloplasty

Catheter balloon mitral valvuloplasty (BMV) was performed in 50 patients and 32 of them undergoing BMV with double balloon technique were studied to evaluate the usefulness of echocardiography in the prediction of early results of BMV. Five echocardiographic variables including mitral valve motion, mitral valve thickness, subvalvular change, commissural calcification and left atrial dimension were evaluated. Each variable was divided into mild, moderate and severe subgroups. Before valvuloplasty there were no differences in mitral valve area among any subgroup for any variable. After valvuloplasty, variables associated with a greater increase in mitral valve area from mild and moderate subgroups than from severe subgroup included mitral valve motion, mitral valve thickness, and subvalvular change, but not commissural calcification or left atrial dimension. We scored the former 3 variables as 0, 1 and 2 points in the mild, moderate and severe subgroups, respectively. The sums of individual scores in these 3 variables were further divided into 3 groups: 12 patients had a lower score (less than 2), 10 patients had a score of 3-4 and 10 patients had a higher score (greater than 5). Patients with lower scores tended to have greater increases in mitral valve areas after valvuloplasty than those with higher scores. Thus, mitral valve motion, mitral valve thickness and subvalvular change may be useful to predict a greater increase in mitral valve area after valvuloplasty. A lower score of echocardiographic variables anticipates successful balloon mitral valvuloplasty, which may be helpful in patient selection.     

Mitral valve replacement with preservation of the subvalvular apparatus

The introduction of the Starr-Edwards valve allowed complete replacement of diseased left-sided heart valves. With improved cardiopulmonary bypass, myocardial protection, and surgical techniques the mortality rate from aortic valve replacement decreased substantially, whereas the mortality rate from mitral valve replacement remained high, largely because of low cardiac output syndrome. Increasing use of mitral valve repair techniques resulted in a marked decrease in short-term and long-term morbidity and mortality when treating patients with mitral regurgitation. Some believed that this resulted from maintenance of the mitral annular papillary muscle continuity during mitral valve repair. Subsequent experimental and clinical studies have validated the positive short-term and long-term effects of maintaining the integrity of the mitral valve subvalvular apparatus. This article considers the history of the clinical use of preservation of the subvalvular apparatus, the physiologic studies examining this concept, and the clinical data available on its use. It also examines the following: 1) mitral stenosis versus mitral regurgitation and the preservation of the subvalvular apparatus; 2) whether the anterior, posterior, or both areas of the subvalvular apparatus should be preserved; and 3) the surgical techniques for the preservation of the subvalvular apparatus and valve implantation.     

人工腱索置入的二尖瓣置换术5年效果分析

目的:评价人工腱索置入的二尖瓣置换术后5年效果。方法:将术后随访>5年的行二尖瓣置换患者分为两组。组1患者二尖瓣置换同时行人工腱索置入;组2二尖瓣置换时保留全部或部分后瓣患者,每组各30例。将术后5年的超声结果进行比较,同时比较术前、术后各组间数据差别。结果:对于二尖瓣替换手术,人工腱索置入与保留瓣下结构患者术后各项指标均有良好的改善,中期效果相当。结论:当二尖瓣置换手术中瓣下结构严重钙化,腱索、乳头肌与瓣膜重度粘连及融合导致其无法保留的风湿性心脏病患者中,人工腱索置入不失为一种合适的选择。     

部分或全部保留瓣下结构的二尖瓣置换术对巨大左室几何学的影响

目的 动态观察二尖瓣置换术(Mitral valve replacement,MVR)后巨大左心室的几何学变化，对比3种不同术式对左心室形态学逆转的影响。方法 回顾性分析1992年1月至2002年1月间48例巨大左心室病人施行二尖瓣置换术后的超声心动图随访资料。结果 保留二尖瓣装置对巨大左心室形态的逆转有效，其中保留全部瓣下结构术后左窒缩小最显，部分保留其次，无保留术后早期缩小晚期再扩大。结论 对于二尖瓣关闭不全为主合并巨大左室。应尽量采用保留瓣下结构的术式，有利于术后晚期左心室形态的逆转。     

Mitral stenosis with notable or important subvalvular changes. Complete open commissurotomies supported by chorda transfer

Since 1983, 40 consecutive patients with mitral stenosis (MS) and significant disease of the subvalvular apparatus underwent open heart mitral commissurotomy (OHMC). The aim of the study was to evaluate the effects of an unrestricted dilatation of the two commissures followed by repair of the subsequent mitral regurgitation. The mitral regurgitation created by this procedure in 24 cases was corrected by transferring 2 to 6 chordae tendinae to the free border of the anterior and/or posterior leaflet in the commissural region. A central regurgitant lesion due to lack of coaptation of the valvular surfaces was treated by annuloplasty with a Carpentier prosthesis in 12 cases. The subvalvular abnormalities were treated by the conventional techniques of fenestration, resection and division of the papillary muscles. Thirty of the 38 survivors had no residual murmur, and 6 had a short low intensity systolic murmur. The 2D echocardiographic study showed no residual stenosis. The residual systolic murmurs were evaluated by pulsed Doppler and corresponded to very localised regurgitation. This extensive operative technique gives very good immediate valvular results which, associated with an adequate subvalvular procedure, are considered to be an important prognostic factor.     

Effect of subvalvular disease on results of percutaneous mitral valvotomy]

In order to study the results of percutaneous mitral valvuloplasty (PMV), subvalvular mitral disease was classified using: 1) the transthoracic echo score (0-4), 2) an index derived from left ventricular angiography defined as the ratio of the distance from the extremity of the papillary muscle and the mitral valve in systole and the distance between the beginning of the aortic root and the apex of the left ventricle in diastole. This index of subvalvular fibrosis could be measured in 80 out of our first 103 PMV performed without complication; the mitral surface are a increased from 1.1 +/- 0.4 to 2.2 +/- 0.8 cm2 (p less than 0.0001). After PMV, mitral regurgitation was observed or was aggravated in 28 patients (35%), by one grade in 25 and by more than one grade in 3. The overall echo score was 8.3 +/- 1.5 and that of subvalvular fibrosis was 2 +/- 0.6. The angiographic index of subvalvular fibrosis was 0.18 +/- 0.04. No correlation was observed between echo and angiographic appreciation of subvalvular fibrosis. Multivariate analyses were selected: 1) the overall echocardiographic score (r = -0.45, p less than 0.0001), but not the angiographic index of subvalvular fibrosis or echocardiographic score of subvalvular fibrosis, was predictive of increase of valve surface area; 2) the absence of mitral regurgitation before PMV (p less than 0.01) and an angiographic index of subvalvular fibrosis less than or equal to 0.15 (p less than 0.03) were predictive of increased mitral regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)     

二尖瓣置换术中保留后瓣及瓣下结构对左心功能的影响

目的评价保留二尖瓣后瓣及瓣下结构对二尖瓣瓣膜置换患者左心功能的影响。方法64例二尖瓣置换患者随机分为两组,保留二尖瓣后瓣及瓣下结构组（MVRP组）34例,全瓣膜切除瓣膜置换组（MVRC组）30例;术前、术后15d和术后3个月分别应用彩色超声多普勒监测MVRP组、MVRC两组左心功能指标。结果MVRP组左心室舒张末期内径、收缩末期内径、左室功能较MVRC组改善显著（P〈0．05）。结论二尖瓣置换术中保留后瓣及瓣下结构有利于改善瓣膜置换术后左心室功能。     

Mitral valve replacement with complete mitral leaflet retention: operative techniques

BACKGROUND AND AIMS OF THE STUDY: This report describes surgical indication and operative technique of complete preservation of the mitral valvular and subvalvular apparatus during mitral valve replacement. METHODS: Twenty patients, 12 with rheumatic lesions and eight with congenital lesions, were operated between 1991 and 1996. The left atrium was opened using a trans-septal approach through the right atrium in 17 patients, and at the intra-atrial groove in three. The valve was sized without excising any mitral valvular or subvalvular tissue. Teflon pledget-reinforced horizontal mattress valve sutures were passed from the left atrium, through the mitral annulus, around the free edge of mitral leaflet, and up through the prosthetic sewing ring. The prosthetic valve was seated and the sutures tied, reefing the native leaflets and compressing them between the sewing ring and native annulus. Thus, chordal tension on the ventricle was evenly maintained. RESULTS: There was no operative or late death. Postoperative results were excellent. Echocardiography showed that none of the patients had any observable anterior leaflet and redundant subvalvular tissue in the left ventricular outflow tract (LVOT); thus, neither LVOT obstruction nor interference with prosthetic valve function occurred. CONCLUSIONS: Based on these findings, it is suggested that when mitral valve replacement is required in patients with mitral insufficiency (MI) or MI with mild stenosis, the mitral valvular and subvalvular tissue should be completely preserved.     

心脏瓣膜病巨大左心室病人的瓣膜置换

目的：探讨瓣膜病巨大左心室病人的临床特点，及影响手术疗效的主要因素，提高瓣膜置换术后的疗效。方法：共47例瓣膜病巨大左心室病人行瓣膜置换术，其中主动脉与二尖瓣双瓣置换35例，二尖瓣置换5例，主动脉置换7例，同时行三尖瓣成形42例，左房折叠4例。结果：术后早期并发症14例(349／6)，死亡2例(4．259／6)，影响瓣膜置换手术早期疗效的主要因素是严重左室扩大，严重左室收缩功能下降，射血分数(EF)＜0．40，左室短轴缩短率(FS)＜0．25和严重低心输出量综合征，和围术期室颤。结论：掌握合适手术时机，注意心肌保护措施，最大限度地保留心内结构是巨大左心室病人瓣膜置换手术成功的重要因素。     

Actuarial analysis of reoperation in patients undergoing open mitral commissurotomy for mitral stenosis

Reoperation is one of the most seriously problematical events in postoperative follow-up of patients undergoing open mitral commissurotomy (OMC) for mitral stenosis. In 217 patients with pure mitral stenosis, even when associated with severe subvalvular changes, the actuarial rate of freedom from reoperation was 94% 12 years after OMC. In contrast, in 85 patients with MS combined with regurgitation, the rate was 66%. In postoperative management of patients undergoing OMC, it is mandatory to know preoperative anatomical findings of the stenosed mitral valve.     

Accessory mitral valve without left ventricular outflow tract obstruction in an adult

Accessory mitral valve is a rare congenital abnormality and an unusual cause of subvalvular obstruction of the left ventricular outflow tract. Accessory mitral valves are usually detected in children due to symptomatic obstruction; isolated nonobstructive accessory mitral valve is rarely seen in adults. We describe the echocardiographic diagnosis of accessory mitral valve as an isolated congenital anomaly not associated with a substantial degree of obstruction of the left ventricular outflow tract in an asymptomatic adult patient. This case highlights the importance of transthoracic and transesophageal echocardiography in the diagnosis and follow-up of this uncommon congenital anomaly.     

Tenting volume: three-dimensional assessment of geometric perturbations in functional mitral regurgitation and implications for surgical repair

BACKGROUND AND AIM OF THE STUDY: Functional mitral regurgitation (FMR) often complicates dilated cardiomyopathy (DCM), and portends a poor prognosis. Debate over the optimal treatment continues, underscoring the present incomplete understanding of the patho-anatomic mechanisms of this disease. Studies of mitral tenting volume and tenting area, and echocardiographic measures of abnormal apical systolic leaflet geometry have linked mitral leaflet deformation with subvalvular left ventricular (LV) remodeling in chronic ischemic MR. The relative contributions of annular versus subvalvular remodeling in FMR due to DCM are less clear. Here, the validity of 3-D measurement of mitral deformation, tenting volume, as a correlate of MR in DCM, was tested. The ability of annular and subvalvular remodeling to predict mitral deformation was then determined. METHODS: Eight sheep underwent placement of radiopaque markers on the mitral annulus and leaflets. Global LV, annular and subvalvular geometry, as well as mitral tenting height, area and volume were calculated before (Control) and after the development of pacing-induced cardiomyopathy and MR (DCM). Multivariable regression determined which measure of mitral deformation was the best predictor of MR. Regression analysis was also used to find geometric predictors of mitral tenting volume. RESULTS: In a multivariable analysis, mitral tenting volume was the only independent predictor of severity of MR (r(2) = 0.79, standard error of estimate (SEE) = 0.58). Increased tenting volume correlated best with increased mitral annular septal-lateral diameter (r(2) = 0.67, SEE = 0.72). CONCLUSION: The 3-D tenting volume correlates best with severity of FMR. Mitral deformation (increased tenting volume) observed in DCM is predicted by annular dilation, but not by subvalvular LV remodeling. These data support the use of an undersized annuloplasty in DCM complicated by FMR, and may guide the rational design of new therapies for this vexing disease.     

Management of Mitral Regurgitation Due to Mitral Prolapse

Opinion statement Notable advances have been made in the treatment of mitral regurgitation, especially the advances resulting from prolapse of the mitral valve with or without a flail leaflet. Prosthetic mitral valve replacement results in a high incidence of postoperative left ventricular systolic dysfunction. Recognition of the importance of the subvalvular apparatus for preserving contractile function has fostered development of new repair techniques that preserve native valve tissue and reduce or eliminate postoperative systolic dysfunction and the need for anticoagulation. Vasoactive medications have a very limited role in the management of patients with primary mitral regurgitation. Better screening tools enable detection of early ventricular decompensation, and appropriate operative interventions continue to significantly reduce the morbidity and mortality associated with mitral regurgitation. Mortality associated with ischemic mitral regurgitation resulting from annular ring dilatation or structural damage associated with rupture of a papillary muscle continues to be high, and the simplest and most expeditious operative intervention is emphasized.