Systolic anterior motion of the mitral valve after mitral valve repair: a method of prevention

Factors predisposing patients to systolic anterior motion of the mitral valve (SAM) with left ventricular outflow tract (LVOT) obstruction after mitral valve repair are the presence of a myxomatous mitral valve with redundant leaflets, a nondilated hyperdynamic left ventricle, and a short distance between the mitral valve coaptation point and the ventricular septum after repair. From December 1999 through March 2000, we used our surgical method in 6 patients with severely myxomatous regurgitant mitral valves who were at risk of developing SAM. Leaflets were markedly redundant in all 6. Left ventricular function was hyperdynamic in 4 patients and normal in 2. Triangular or quadrangular resection of the midportion of the posterior leaflet and posterior band annuloplasty were performed. To prevent SAM and LVOT obstruction, extra, posteriorly directed, mid-posterior-leaflet secondary chordae tendineae, which would otherwise have been resected, were transferred to the underside of the middle of the mid-anterior leaflet with a small piece of associated valve as an anchoring pledget. This kept the redundant anterior leaflet edge, which extended below the coaptation point, away from the LVOT No post-repair SAM or LVOT obstruction was observed on intraoperative or discharge echocardiography. All patients had no or trivial residual mitral regurgitation. We conclude that extra chordae tendineae, when available, can be used in mitral valve repair to tether the redundant anterior leaflet and thus prevent it from flipping into the LVOT. This will theoretically prevent SAM and LVOT obstruction in patients with risk factors for SAM.     

Transient left ventricular outflow tract obstruction with systolic anterior motion of the mitral valve: A stunning cause

Left ventricular outflow tract obstruction (LVOTO) and systolic anterior motion (SAM) of the mitral valve may have various etiologies, of which hypertrophic cardiomyopathy is the most common. More rarely, an acute coronary syndrome, myocardial stunning, and takotsubo cardiomyopathy may give rise to LVOTO and SAM. Here, we present a 70‐year‐old female patient with a non‐ST‐elevation acute coronary syndrome treated with percutaneous coronary intervention. Echocardiography the day after, because of dyspnea and hypotension, revealed apical akinesia, LVOTO, and SAM, which proved completely reversible after treatment with a β‐blocker and a 2‐month follow‐up period. It was concluded that postischemic apical stunning had caused LVOTO and SAM.     

Mitral valve remodeling in the development of obstructive hypertrophic cardiomyopathy

Approximately 2/3 of patients with hypertrophic cardiomyopathy (HCM) have significant left ventricular outflow tract obstruction (LVOTO), which is caused by the interaction mitral valve apparatus and the hypertrophied septum. The contribution of mitral valve remodeling to the development of obstruction over time has never been described. We analyzed retrospectively 40 patients with HCM and no baseline obstruction followed up for a median of 2179 days. At follow up, 13 patients developed significant LVOTO. Patients who developed LVOTO had longer posterior leaflets and longer anterior leaflet residual length.     

Left ventricular outflow tract obstruction after mitral valve repair treated with alcohol septal ablation

Left ventricular outflow tract (LVOT) obstruction due to systolic anterior motion of the mitral valve (SAM) occurs in 4–5% of patients after mitral valve repair. If conservative treatment is unsuccessful, reoperation is indicated. Treatment options include repeated mitral valve repair or valve replacement and septal myectomy if hypertrophy is present. We report a case of a patient with pre‐operatively undiagnosed hypertrophic cardiomyopathy who suffered from progressive dyspnea post‐operation due to severe LVOT obstruction with SAM. This case was successfully treated with catheter‐based alcohol septal ablation. © 2013 Wiley Periodicals, Inc.     

Midventricular obstruction--a form of hypertrophic obstructive cardiomyopathy--and systolic anterior motion of the mitral valve

Hypertrophic cardiomyopathy (HCM) has various manifestations with respect to the localization of the hypertrophy. In this study we report clinical, electrocardiographic (ECG), echocardiographic (echo), and hemodynamic findings in midventricular obstruction (MO), an uncommon form of hypertrophic obstructive cardiomyopathy (HOCM) in 9 patients. The prevalence of systolic anterior motion of anterior mitral leaflet (SAM) in MO, an echocardiographic diagnostic hallmark in HOCM, was another purpose of this study. All patients had complete clinical, ECG, echo, and hemodynamic workup, including left ventricular (in 4 patients simultaneous biventricular, SBVA) and coronary angiograms. All patients had dyspnea and palpitations, chest pain, 2 had syncope. In the ECG, atrial fibrillation was present in 2, and left ventricular hypertrophy in 9 patients. Septal and left ventricular free wall thickening was significantly present in all patients in echo, and SAM in 1 patient. The intraventricular gradient (IVG) was 40-176 mmHg, in 1 case 40 mmHg by provocation, Brockenbrough was positive in all patients. Two patients had right ventricular IVG. A positive beta-blocking agent effect was present in 6 cases. The best localization of the obstruction was possible with SBVA and 2D-echo. We conclude that MO has all the signs of HOCM, but SAM in echocardiography is uncommon. SAM is occasionally present and is not a necessary factor to produce an intraventricular pressure gradient in HOCM, especially in MO. It seems that hypertrophic right ventricular obstruction is relatively common in MO (2 of 9 cases), and may have the same obstructive mechanism.     

Systolic anterior motion of the mitral valve in hypertrophic cardiomyopathy. A cross-sectional echocardiographic study

Different cross-sectional echocardiographic patterns of systolicanterior motion of the mitral valve (SAM) have been observedin patients with hypertrophic cardiomyopathy. Chordae tendineaeand/or the free edge of the mitral valve were seen to be involvedin some: SAM(c). The body of the mitral valve encroached uponthe left ventricular outflow tract in this movement in a secondgroup: SAM(v). Other patients did not show SAM. A study of 27patients was performed to investigate the relationship of thesepatterns of SAM to the subaortic gradient as well as the prevalenceand degree of mitral re gurgitation. The absence of SAM correlatedwith no obstruction and 29% prevalence of mitral re gurgitation.In SAM(c), the mean gradient was 10±10 mmHg. (0–35mmHg), and mitral regurgitation involved 36% of the patients.In SAM(v) the mean gradient found was 81 ±37 mmHg (20–150),and 67% had mitral regurgitation. In situations where mitralregurgitation was most prevalent its degree was greatest. Inconclusion: (1) chordal or leaflet participation in SAM is relevantto the presence and degree of obstruction: (2) leaflet involvementusually implies severe obstruction: (3) distortion of the mitralvalve apparatus may contribute to the genesis of mitral.     

Dynamic mild subaortic left ventricular obstruction caused by an accessory mitral valve attached to the anterior mitral valve in a young pregnant woman

Accessory mitral valve tissue is an extremely rare congenitalcardiac anomaly of embryologic development of the endocardialcushion. This anomaly is often associated with left ventricularoutflow tract obstruction (LVOTO). A 26-year-old pregnant femalewas referred to our Department of Cardiology with exertionalshortness of breath and tachycardia. Transthoracic and transesophagealechocardiography revealed a flexible circular (1.3 x 1.4 cm),mobile structure attached to the ventricular side of anteriormitral valve leaflet, with chordal attachments structure fromanterior papillary muscle. This picture is compatible with aparachute-like accessory mitral valve tissue. We performed anechocardiographic exercise test that shows a systolic flow turbulencestarting immediately proximal to this structure, resulting ina small increase in left ventricular outflow tract (LVOT) gradient(30 mmHg). Therefore we started low dose of beta-blocker therapyin order to decrease heart frequency and reduce the future riskof a worsening of an LVOT dynamic obstruction. Transthoracic and transesophageal echocardiography is criticalfor the differential diagnosis of LVOT and in the managementof accessory mitral valve tissue. In patients without rest andonly an exertional mild LVOTO and no other cardiac malformations,prophylactic removal of mitral accessory tissue excision isnot required; antibiotic prophylaxis for endocarditis can beindicated and a regular follow-up is recommended to identifyany progression in LVOTO entity.     

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.     

Echocardiographic correlates of left ventricular outflow obstruction and systolic anterior motion following mitral valve repair

BACKGROUND AND AIM OF THE STUDY: Systolic anterior motion (SAM) of the mitral valve resulting in left ventricular outflow obstruction is a well-recognized complication of repair of the degenerative myxomatous mitral valve. A precise mechanism is unknown. A current approach consists of sliding annuloplasty of the posterior leaflet. It was postulated that excess tissue of the anterior mitral leaflet (AML) was as equally (or more) important as the excess posterior mitral leaflet (PML) tissue in the development of SAM subsequent to valve repair. METHODS: Thirty-two patients without post-repair SAM (No-SAM group) were compared with eight patients with SAM (SAM group). The AML and PML heights and the mitral annulus diameter were measured by TEE using mid-esophageal four-chamber and long-axis planes. RESULTS: Pre-repair TEE showed the AML height to be greater in the SAM group (p = 0.04), and that of the posterior leaflet tended to be greater (p = 0.08), whilst the annular dimensions were similar in both groups. In the post-repair status, the AML height was markedly greater (p = 0.005) and the annulus markedly smaller (p = 0.001) in the SAM group. Post-repair assessment showed the relative difference between AML height and annular dimension (AML - Ann) as well as the difference between combined leaflet heights and annular dimension (AML + PML - Ann) to be strikingly greater in the SAM group as compared with the No-SAM group (p = 0.001). CONCLUSION: A disparity between dimension of the annulus following mitral valve repair and combined heights of the two leaflets explains post-repair SAM. The AML height is a more important factor in the development of SAM. Thus, surgical techniques to reduce AML heights should be considered in patients with disproportionately large anterior leaflets in order to prevent SAM. Selection of size of the annuloplasty ring should take into consideration the height of the AML.     

MitraClip‐induced systolic anterior motion complicated by pericardial effusion: A case report

Systolic anterior motion (SAM) of the anterior mitral leaflet is a well reported complication of surgical mitral valve repair (MVR). In the current report, we present a case of SAM with left ventricular outflow tract obstruction (LVOTO) which occurred after transcatheter mitral valve repair (TMVR) using the MitraClip device. LVOTO was caused by the combination of protrusion of the MitraClip device into the LVOT and underfilling of the left ventricle due to pericardial effusion and atrial fibrillation. Rapid clinical resolution and marked decline in LVOT pressure gradient occurred following surgical drainage and windowing of the pericardium. We conclude that SAM and LVOTO could occur after TMVR. Seeking and addressing reversible aggravators of LVOTO including pericardial effusion is essential and could potentially make the difference between a successful procedure and a failed one. © 2016 Wiley Periodicals, Inc.     

Clinical utility of new real time three-dimensional transthoracic echocardiography in assessment of mitral valve prolapse

BACKGROUND: Noninvasive and accurate assessment of mitral valve anatomy has become integral in the presurgical evaluation of patients with mitral valve prolapse (MVP). Recently developed real time three-dimensional (RT3D) ultrasound allows online acquisition, rendering, and can provide accurate information on cardiac structures. We sought to evaluate the feasibility of RT3D for the assessment of MVP segments when compared with transesophageal echocardiography (TEE) and intraoperative findings. METHODS: We examined 42 patients with MVP using RT3D, two-dimensional (2D) transthoracic echocardiography (TTE) and TEE. For RT3D analysis, cropping planes were used to slice the 3D volume on line to visualize the prolapsed segments of the mitral valve leaflets. The mitral valve was divided into six segments based on the American Society of Echocardiography's recommendations. Two experienced cardiologists evaluated echocardiographic images. RESULTS: Adequate RT3D images of the mitral valve were acquired in 40 out of 42 patients. The sensitivity and specificity of RT3D for defining prolapsed segments when compared with TEE were 95% and 99%, respectively (anterior leaflet: 96% and 99%, posterior leaflets: 93% and 100%, respectively). The sensitivity and specificity of TTE were 93% and 97%, respectively (anterior leaflet: 96% and 98%, posterior leaflets: 90% and 97%, respectively). Interobserver agreement for RT3D (Kappa 0.95, 95% confidence interval [CI] 0.91-1.00) was significantly greater than for TTE (Kappa 0.85, 95% CI 0.78-0.93) (P < 0.05). The elapsed time for completion of RT3D (14.4 +/- 2.8 min) was shorter than for TEE (26.4 +/- 4.7 min, P < 0.0001) and TTE (19.0 +/- 3.1 min, P< 0.0001). CONCLUSIONS: RT3D is fast, accurate, and highly reproducible for assessing MVP.     

Transient severe mitral regurgitation after mitral valve repair is associated with a poor clinical outcome: a small case series

Background: During mitral valve repair, patients with transesophageal echo‐detected immediate postoperative systolic anterior motion of the mitral valve (SAM) and mitral regurgitation (MR) are successfully medically managed. They have been shown to do well in a short‐term follow‐up. However, the long‐term outcome has not been investigated. The objective of this project was to investigate the long‐term outcome of these patients. Methods: This is an observational, retrospective study of 385 patients who underwent MVR. All cases of SAM and MR in this report were successfully medically managed with conservative therapy preventing the need for immediate surgical reintervention. Patients were divided into two groups based on the severity of MR. Group I had grade ≤ 2 + MR (     

瓣中瓣置入术治疗二尖瓣关闭不全16例报告

二尖瓣关闭不全患者行常规二尖瓣置换术后常有左室功能恶化，有人推测术中二尖瓣结构的破坏是导致术后左室功能不全的主要机制之一。从１９９１年５月～１９９５年５月，我们对１６例二尖瓣关闭不全患者实施了一种新的二尖瓣置换术，即“瓣中瓣”置入术。术中保留全部二尖瓣瓣叶及瓣下结构，人工瓣置入固定后，前、后瓣叶均卷缩折叠于缝合环下。术后所有患者病情平稳，仅３例需要很少量的正性肌力药物支持，且都能在术后３６小时内脱离呼吸机。经超声心动图测定，术后左室功能很快恢复，所有患者均痊愈出院。结果表明：对二尖瓣关闭不全及其合并轻度狭窄者采用瓣中瓣置入术，有利于术后左室功能的恢复，瓣中瓣置入术是一种安全和有效的手术方法。     

经食管实时三维超声检测风湿性心脏病患者二尖瓣对合指数的研究

目的:应用经食管实时三维超声心动图检测风湿性心脏病(RHD)患者二尖瓣对合指数,探讨其定量二尖瓣对合程度的可行性及临床价值。方法:选取合并有二尖瓣反流的RHD患者16例作为RHD组,无瓣膜病变且无瓣膜反流的志愿者16例作为对照组。①2组均行经食管实时三维超声心动图检查,应用二尖瓣定量分析程序对三维原始图像进行脱机分析,对相同时相的二尖瓣瓣叶及瓣环进行逐帧描记,分别获取2组在收缩末期及舒张早期的二尖瓣瓣叶面积、瓣环三维周长、瓣环二维投影面积。计算出2组的二尖瓣对合面积及对合指数。②2组均行常规超声心动图检查,测量2组舒张末期左室内径、收缩末期左室内径、左房内径及左室射血分数,并测量RHD组二尖瓣反流面积。结果:RHD组与对照组均能成功得到二尖瓣对合面积并可以计算出二尖瓣对合指数,且RHD组的对合指数明显小于对照组[(10.4±2.8)%:(28.1±3.8)%,P<0.001]。2组的前瓣叶对合指数均小于后瓣叶(RHD组P=0.03,对照组P=0.075)。RHD组的二尖瓣瓣叶面积、左房内径、瓣环三维周长、瓣环二维投影面积均大于对照组(均P<0.01)。结论:应用经食管实时三维超声心动图技术及相关二尖瓣定量分析程序可得到二尖瓣对合指数。合并有二尖瓣反流的RHD患者二尖瓣对合指数明显小于正常人。因此该参数可作为定量评估RHD患者二尖瓣对合程度的形态学指标。     

The natural history of aortic valve disease after mitral valve surgery

OBJECTIVES

The present study evaluates the long-term course of aortic valve disease and the need for aortic valve surgery in patients with rheumatic mitral valve disease who underwent mitral valve surgery.

BACKGROUND

Little is known about the natural history of aortic valve disease in patients undergoing mitral valve surgery for rheumatic mitral valve disease. In addition there is no firm policy regarding the appropriate treatment of mild aortic valve disease while replacing the mitral valve.

METHODS

One-hundred thirty-one patients (44 male, 87 female; mean age 61 ± 13 yr, range 35 to 89) were followed after mitral valve surgery for a mean period of 13 ± 7 years. All patients had rheumatic heart disease. Aortic valve function was assessed preoperatively by cardiac catheterization and during follow-up by transthoracic echocardiography.

RESULTS

At the time of mitral valve surgery, 59 patients (45%) had mild aortic valve disease: 7 (5%) aortic stenosis (AS), 58 (44%) aortic regurgitation (AR). At the end of follow-up, 96 patients (73%) had aortic valve disease: 33 AS (mild or moderate except in two cases) and 90 AR (mild or moderate except in one case). Among patients without aortic valve disease at the time of the mitral valve surgery, only three patients developed significant aortic valve disease after 25 years of follow-up procedures. Disease progression was noted in three of the seven patients with AS (2 to severe) and in six of the fifty eight with AR (1 to severe). Fifty two (90%) with mild AR remained stable after a mean follow-up period of 16 years. In only three patients (2%) the aortic valve disease progressed significantly after 9, 17 and 22 years. In only six patients of the entire cohort (5%), aortic valve replacement was needed after a mean period of 21 years (range 15 to 33). In four of them the primary indication for the second surgery was dysfunction of the prosthetic mitral valve.

CONCLUSIONS

Our findings indicate that, among patients with rheumatic heart disease, a considerable number of patients have mild aortic valve disease at the time of mitral valve surgery. Yet most do not progress to severe disease, and aortic valve replacement is rarely needed after a long follow-up period. Thus, prophylactic valve replacement is not indicated in these cases.     

Pigtail catheter “propping” for MitraClip percutaneous transcatheter mitral valve repair

In recent years percutaneous therapy has emerged as a feasible and effective option for the treatment of mitral regurgitation, particularly in cases where the risks of conventional cardiac surgery are prohibitively high. To date the most widely used percutaneous approach is beating heart, edge‐to‐edge repair with the MitraClip device (Abbott Vascular‐Structural Heart, Menlo Park, CA). The technique requires simultaneous grasping and approximation of both mitral valve leaflets prior to securing and releasing the clip. However, this may be technically challenging or indeed impossible in patients with failure of coaptation, particularly when there is a large coaptation gap. We present an approach for overcoming this relatively common obstacle based on “propping” the anterior mitral valve leaflet toward its posterior counterpart with a diagnostic pigtail catheter to reduce the coaptation gap and to allow grasping of both leaflets without difficulty. © 2016 Wiley Periodicals, Inc.     

Reference values describing the normal mitral valve and the position of the papillary muscles

In patients with functional mitral regurgitation (MR), the principal mechanisms are insufficient coaptation due to dilatation of the mitral annulus (MA), global ventricular dysfunction with tethering of leaflets, or restricted leaflet motion with incorrect apposition due to regional ventricular dysfunction and displacement of the papillary muscles (PMs). These different entities often coexist and for this reason, knowledge of the normal reference values describing the shape and size of the MA and the position of the PMs is essential. In the present study, we describe the MA dimensions and the position of the PMs in a group of normal individuals (n = 38, 60% women, age [mean +/- SD] 51 +/- 9 years and BSA 1.83 +/- 0.16 m(2)) investigated with transthoracic echocardiography. The anteroposterior dimension (AP) of the ellipse-shaped MA was measured in a parasternal long axis, while the distance from the posteromedial (PoM) to the anterolateral (AL) commissure was measured in a parasternal short axis (CC). The annular area was calculated assuming elliptic geometry. The MA shape was described by the ratios AP/CC and AP/length of the anterior leaflet. The PMs' position was described by the following distances: (a) from the MA to the tip of the PoM and AL, PMs measured in a modified two-chamber view where both PMs could be identified, (b) the interpapillary distance, and (c) the tethering distance from the tip of the PM to the contralateral MA. These data on the normal mitral valve morphology should provide useful information when assessing the underlying mechanism of functional MR.     

Use of three‐dimensional transesophageal echocardiography to evaluate mitral valve morphology for risk stratification prior to mitral valvuloplasty

Mitral stenosis is often managed percutaneously with an interventional procedure such as balloon commissurotomy. Although this often results in an increased mitral valve area and improved clinical symptoms, this procedure is not benign and may have serious complications including the development of hemodynamically significant mitral valve regurgitation. Multiple scoring systems have been developed to attempt to risk stratify these patients prior to their procedure. Case: A 64‐year‐old patient underwent an emergent mitral valve replacement after having percutaneous mitral balloon commissurotomy complicated by development of severe mitral regurgitation. Prior to valvuloplasty, her mitral valve was evaluated by traditional methods including calculation of a Wilkins score. Her mitral valve was evaluated after valvuloplasty and preoperatively with three‐dimensional transesophageal echocardiography. This examination demonstrated heterogeneous distribution of calcification affecting the mitral valve commissures more than the leaflets, which is consistent with the noncommissural leaflet tearing that occurred during her procedure, causing severe mitral regurgitation. In the future, careful 3D evaluation of mitral valve morphology including leaflets, annular calcification, and subvalvular apparatus may help risk stratify patients prior to intervention.     

Transesophageal echocardiography as predictor of mitral valve repair

BACKGROUND AND AIM OF THE STUDY: Mitral valve repair has recently emerged as the treatment of choice in patients presenting with insufficiency due to valve prolapse. The study aims were to evaluate: (i) the clinical presentation in a consecutive series of patients with mitral valve prolapse undergoing surgical repair; (ii) the correlation between pre- and intraoperative echocardiographic features and surgical findings in these patients; and (iii) whether clinical and echocardiographic data may predict surgical outcome. METHODS: Between March 1997 and May 2000, 152 patients (110 men, 42 women; mean age 59+/-13 years) were recruited into the study. All patients had myxomatous mitral valve disease causing severe regurgitation and underwent systematic examination by transesophageal echocardiography (TEE) for clear delineation of the three scallops of the posterior leaflet and juxtaposed segments of the anterior leaflet. RESULTS: In 119 patients (78%) a flail valve was documented by TEE and confirmed on surgical inspection; an anterior leaflet chordal rupture was not visualized by TEE in one case. In 15 cases (10%) there was flail of the anterior leaflet, and in 105 cases (69%) flail of the posterior leaflet. A bileaflet complex prolapse without chordal rupture was found in 32 cases. On the basis of TEE evaluation, mitral valve replacement was performed electively in 10 patients (7%); the other 142 (93%) underwent mitral valve repair. Adequate repair was obtained in 93% of cases; residual mitral regurgitation (eight cases; grade 3+) and mitral stenosis (one case) were documented by intraoperative TEE, and nine patients (6%) underwent valve replacement. CONCLUSION: The majority of patients with myxomatous mitral valve prolapse and severe regurgitation undergoing valve repair have chordal rupture of the posterior mitral leaflet, a condition in which results of valve repair are excellent. TEE provides a powerful means to define the mechanisms of mitral regurgitation and to identify the suitability of patients for valvuloplasty.