Accessory Mitral Valve Tissue Research Articles

Accessory mitral valve tissue: an updated review of the literature

Accessory mitral valve tissue (AMVT) is a rare congenital cardiac anomaly sometimes responsible for left ventricular outflow tract (LVOT) obstruction. It is diagnosed during both neonate-childhood and adult periods in patients usually symptomatic for dyspnoea, chest pain, palpitations, fatigue, or syncope. Nevertheless, AMVT is often an incidental finding. AMVT is most often associated with other cardiac and vascular congenital malformations, such as septal defects and transposition of the great arteries. Surgery is indicated only in cases of significant LVOT obstruction and in patients undergoing correction of other cardiac malformations or exploration of an intracardiac mass. Two-dimensional echocardiography, both transthoracic and transoesophageal, is considered the main imaging modality for AMVT diagnosis and patient follow-up. The recent introduction of three-dimensional echocardiography allows a more realistic characterization of this entity. We present three clinical cases in which AMVT was incidentally diagnosed during standard echocardiography and an updated review of the literature highlighting the usefulness of echocardiography for AMVT morphological and functional characterization as well as the most relevant clinical implications due to its discovery.

Occlusion of the retinal artery occlusion by undiagnosed accessory mitral valve tissue

Occlusion of the retinal artery occlusion by undiagnosed accessory mitral valve tissue

Isolated accessory mitral valve tissue in an asymptomatic elderly patient.

Accessory mitral valve tissue is a membranous or tumor-like structure observed in the left ventricular outflow tract. This congenital anomaly has been reported in more than 100 cases since 1842; however, most of them were found in patients with complex cardiac malformations. We report a 72-year-old Asian woman with isolated accessory mitral valve tissue incidentally found during the evaluation of hypertension and arrhythmia. Her left ventricular outflow tract obstruction was mild. Because worsening of the left ventricular outflow tract obstruction was reported in patients without significant obstruction at the time of diagnosis, periodical echocardiographic follow-up is necessary.

Isolated non-obstructive accessory mitral valve tissue in an adult mimicking ruptured chordae

Accessory mitral valve tissue is commonly associated with other congenital heart diseases and is usually detected in children causing left ventricular outflow tract obstruction. We present an adult patient with isolated non-obstructive accessory mitral valve tissue that was mimicking ruptured chordae of the mitral valve. Accessory mitral valve tissue in adults is very rare and can mimick various causes of left ventricular outflow tract obstruction. This patient represents the first case in literature wherein an unobstructive accessory mitral valve tissue simulated a ruptured chordae. This case illustrates that in patients with suspected mitral valve chordae rupture without any mitral regurgitation, this diagnosis should be considered, which can have therapeutic implications.

Four‐Dimensional Visualization of Accessory Mitral Valve Tissue and Cleft Mitral Valve Movement

Mini‐AbstractA 26‐year‐old woman was referred to our department due to cardiac tumor. She was asymptomatic, and transthoracic echocardiography showed accessory mitral valve tissue (AMVT) associated with cleft mitral valve. There was no left ventricular outflow obstruction, but we could identify the three‐dimensional movement of AMVT and cleft mitral valve. Four‐dimensional transthoracic echocardiography enabled us to reveal the real time movement of these structures precisely. In particular, en face visualization of cleft mitral valve and accessory mitral valve cannot be obtained by two‐dimensional echocardiography.

Association between Anomalous Origin of the Left Main and Accessory Mitral Valve Tissue

A 73-year-old man presented to our department for ischemic alterations appeared during a stress electrocardiogram. The diagnostic process including coronary angiography, cardiac computed tomography and echocardiogram revealed an anomalous origin of the left main coronary artery from the commissural region between the left and the non-coronary Valsalva sinus associated with non-obstructive accessory mitral valve tissue. Although these malformations are relatively common the association is not described in literature to date.

Accessory mitral valve tissue: Appearance on cardiac computed tomography

Accessory mitral valve tissue is an uncommon congenital malformation and a rare cause of left ventricular outflow tract obstruction. Although echocardiography provides a "gold standard" for evaluation of valves, the high temporal and spatial resolutions of computed tomography technology makes it useful in the assessment of valvular structure and function.

Exuberant accessory mitral valve tissue with possible true parachute mitral valve: a case report

IntroductionA parachute mitral valve is defined as a unifocal attachment of mitral valve chordae tendineae independent of the number of papillary muscles. Data from the literature suggests that the valve can be distinguished on the basis of morphological features as either a parachute-like asymmetrical mitral valve or a true parachute mitral valve. A parachute-like asymmetrical mitral valve has two papillary muscles; one is elongated and located higher in the left ventricle. A true parachute mitral valve has a single papillary muscle that receives all chordae, as was present in our patient. Patients with parachute mitral valves during childhood have multilevel left-side heart obstructions, with poor outcomes without operative treatment. The finding of a parachute mitral valve in an adult patient is extremely rare, especially as an isolated lesion. In adults, the unifocal attachment of the chordae results in a slightly restricted valve opening and, more frequently, valvular regurgitation.Case presentationA 40-year-old Caucasian female patient was admitted to a primary care physician due to her recent symptoms of heart palpitation and chest discomfort on effort. Transthoracic echocardiography showed chordae tendineae which were elongated and formed an unusual net shape penetrating into left ventricle cavity. The parasternal short axis view of her left ventricle showed a single papillary muscle positioned on one side in the posteromedial commissure receiving all chordae. Her mitral valve orifice was slightly eccentric and the chordae were converting into a single papillary muscle. Mitral regurgitation was present and it was graded as moderate to severe. Her left atrium was enlarged. There were no signs of mitral stenosis or a subvalvular ring. She did not have a bicuspid aortic valve or coarctation of the ascending aorta. The dimensions and systolic function of her left ventricle were normal. Our patient had a normal body habitus, without signs of heart failure. Her functional status was graded as class I according to the New York Heart Association grading.ConclusionsA recently published review found that, in the last several decades, there have been only nine adult patients with parachute mitral valve disease reported, of which five had the same morphological characteristics as our patient. This case presentation should encourage doctors, especially those involved in echocardiography, to contribute their own experience, knowledge and research in parachute mitral valve disease to enrich statistical and epidemiologic databases and aid clinicians in getting acquainted with this rare disease.

Accessory mitral tissue - an unusual cause of left ventricular outflow tract obstruction

Accessory mitral valve tissue is one of the rare anomalies of embryonic development of the endocardial cushion. We describe here a case of a 9 year old male who presented with dyspnoea on exertion. Transthoracic and transesophageal echocardiography revealed aneurysm of membranous part of the interventricular septum producing left ventricular outflow obstruction. Left ventriculography showed a filling defect in the area of mitral aortic interventricular fibrosa probably a localized subaortic membrane. But intraopertive findings showed an accessory mitral valve tissue attached to the annulus of anterior leaflet with its chordal attachment to the papillary muscles of normal mitral valve and to the interventricular septum. The anomalous tissue was excised with its attachment through the aortotomy and left atriotomy. We emphasize, that fixed type of left ventricular outflow tract obstruction produced by an accessory mitral tissue can mimic an aneurysm of the interventricular septum on echocardiography and surgical excision through bicameral approach is recommended.

Asymptomatic Accessory Mitral Valve Tissue Diagnosed by Echocardiography

A 19-year-old male patient was presented with a complaint of palpitation. His physical examination and 12-lead electrocardiogram were normal. Transthoracic echocardiography revealed a mobile, chord-like structure, attached to the anterior papillary muscle and ventricular surface of the anterior mitral leaflet moving in the systole into the left ventricular outflow tract (arrow) (Fig. 1). There was no mitral regurgitation. Doppler examination showed a maximal 20 mm Hg gradient in the left ventricular outflow tract area. Transoesophageal echocardiography revealed an accessory mitral valve tissue (arrow), which adheres to the anterior mitral valve leaflet, and ballooning into the left ventricular outflow tract during the systole (Fig. 2). The patient was followed-up with periodical echocardiographic examinations, and without any surgical intervention. Accessory mitral valve tissue is a rare anomaly of embryologic development of the endocardial cushion. It may be associated with complex cardiac congenital malformations, can cause the left ventricle outflow tract obstruction and valve insufficiency.1),2) In patients with accessory mitral valve tissue, surgery is mandatory if there is significant obstruction in the left ventricular outflow tract, severe valvular regurgitation or any complication associated with this accessory tissue.3) Fig. 1 Fig. 2

Accessory mitral valve tissue: an unusual cause of congenital mitral stenosis

Accessory mitral valve tissue (AMVT) is a rare congenital anomaly of endocardial cushion. Usually, it arises from the anterior mitral leaflet and causes the left ventricular outflow tract obstruction. We report here the first and a rarest presentation of the AMVT in a 19-year old female patient diagnosed to have double outlet right ventricle, ventricular septal defect (VSD), infundibular stenosis and congenital mitral stenosis (MS). She presented with a history of shortness of breath and chest pain over 3 years. Diagnosis was made by chest X-ray, transthoracic and transoesophageal echocardiography, which was confirmed by cardiac catheterization, and angiography. A successful closure of the VSD with excision of the right ventricular bundle and excision of the AMVT was done. Post-operative course was uneventful and an echocardiogram before the discharge showed no residual shunt, no right ventricular outflow gradient or mitral regurgitation, and the gradient across the mitral valve was 5/3 mmHg. We emphasize that, although AMVT commonly produces left ventricular outflow tract obstruction, it should be considered a rare but an important cause of congenital MS.

An Accessory Mitral Valve Leaflet Causing Left Ventricular Outflow Tract Obstruction and Associated with Severe Aortic Incompetence

This case report describes a 20-year-old woman with Turner's syndrome who presented with reduced effort tolerance limited by dyspnea. She had previously been on pediatric cardiology follow-up for congenital subvalvular aortic stenosis first diagnosed at age 7. Unfortunately she defaulted after two visits before any intervention could be done. Transthoracic echocardiography demonstrated severe aortic incompetence (AI) with a membrane-like structure in the left ventricular outflow tract (LVOT). The mean pressure gradient across the LVOT on continuous wave Doppler was 41 mmHg. The membranous interventricular septum appeared aneurysmal and it was observed that the "subaortic membrane" had a connection to the anterolateral papillary muscle via a strand of chordal tissue. Further images were captured using two-dimensional and three-dimensional transthoracic and transesophageal echocardiography (iE33, Philips Medical Systems, Andover, MA, USA). After a review of the literature it was concluded that this appeared to be an accessory mitral valve (AMV) leaflet causing LVOT obstruction associated with AI. AMV tissue is a rare congenital malformation causing LVOT obstruction. Because it is so unusual, it may not be immediately recognizable even in a high volume echocardiography laboratory. The clue which helped with the diagnosis was the strand of chordal tissue which connected the mass to the papillary muscle. This anomaly is often associated with LVOT obstruction.

Tricky image of exuberant accessory mitral valve tissue with partial interchordal space obliteration

A 74-year-old man was referred for mitral valve surgery of symptomatic (weakness and fatigue) prolapse-related mitral regurgitation. He had a past medical history of hypertension, dyslipidaemia, and overweight. His initial evaluation consisted in transthoracic echocardiography which documented the presence of severe mitral regurgitation due to posterior leaflet prolapse ( Panels A and B ; see Supplementary data online, Movie S1 …

Imaging Phenotype Versus Genotype in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a common monogenetic cardiac disease with a prevalence of 0.2%1 that usually is inherited as an autosomal dominant trait with variable penetrance and expression. Clinically, HCM is defined by the presence of left ventricular (LV) hypertrophy (LVH) unexplained by abnormal loading conditions.1 The natural history varies from an asymptomatic course to drug-refractory angina/dyspnea, sudden cardiac death (SCD), and end-stage heart failure. The incidence of HCM-related SCD is approximately 1% to 2% in children and adolescents and 0.5% to 1% in adults.2,3 In this review, we examine the impact of advanced diagnostic imaging technologies on HCM, with particular emphasis on the detection of particular genetic subtypes. In ≈60% of cases, HCM is inherited as an autosomal dominant trait caused by mutations in genes coding for cardiac sarcomere proteins (Figure 1).4–7 Mutations in genes encoding Z-disc proteins and proteins involved in calcium regulation account for <5% of cases. The absence of sarcomeric gene mutations can be explained by limitations of current mutation detection techniques or mutations in as yet unidentified genes, but in some cases, hypertrophy is caused by other diseases that mimic the phenotype of sarcomeric protein disease. Table 1 lists genetic disorders associated with HCM. Figure 1. A schematic illustration of a cardiac sarcomere. View this table: Table 1. Currently Known Genes Implicated in HCM More than 600 different sarcomeric gene mutations are reported in patients with HCM.8–16 The majority are missense mutations, but nonsense, frameshift, and in-frame insertion/deletion mutations also occur. Most mutations are characterized by incomplete penetrance and variable clinical expression likely due to locus heterogeneity and the effect of mutations at different locations within the same gene. Most mutations probably have a dominant negative effect on sarcomere function, but in some cases, haploinsufficiency (ie, only a single functional …

Accessory Mitral Valve Tissue Causing Severe Left Ventricular Outflow Tract Obstruction in a Post-Senning Patient with Transposition of the Great Arteries

Accessory mitral valve tissue is a rare congenital anomaly associated with congenital cardiac defects and is usually detected in the first decade of life. We describe the case of an 18-year old post-Senning asymptomatic patient who was found to have accessory mitral valve tissue on transthoracic echocardiography producing severe left ventricular outflow tract obstruction.

Accessory Mitral Valve Associated With Mitral Cleft, Bicuspid Aortic Valve, and Aortic Coarctation

![Figure][1] ![Figure][1] [![Graphic][3] ][3] Transthoracic echocardiogram showed accessory mitral valve tissue (red arrow) attached to the anterior leaflet, encroaching into the left ventricular outflow tract without obstruction. ![Figure][1] [![Graphic][4] ][4]

Congenital Accessory Mitral Valve Tissue Anomaly in a Patient with Genetically Confirmed Hypertrophic Cardiomyopathy

Accessory mitral valve tissue is a rare congenital cardiac anomaly that was initially described in children in association with other cardiac congenital abnormalities and, more recently, has also been reported in adults. The authors report a patient with genetically confirmed hypertrophic cardiomyopathy who also had a highly mobile, free-floating membrane-like structure in contiguity with the ventricular side of the anterior mitral valve leaflet, a feature consistent with the diagnosis of accessory mitral valve tissue.

Long-term Outcome and Risk of Heart Block After Surgical Treatment of Subaortic Stenosis

Although mortality following repair of subaortic obstruction is low, aggressive resection may increase morbidity. We sought to evaluate outcomes and risk of atrioventricular heart block (AVB) after subaortic resection in the current era. Simple obstruction was defined as a discrete subaortic membrane and complex as multilevel or diffuse narrowing. Limited resection included membranectomy and limited myomectomy. Aggressive resection included Konno, modified Konno, and Ross. Specified variables were obtained from a chart review. The 185 consecutive patients (1991-2008) ranged in age from 1 day to 21.8 years (5.1 ± 5.1 years) with 2 early and 4 late deaths. Actuarial survival was 97%, 95%, and 95% at 1, 5, and 10 years, respectively. Reoperations were required in 29 of 185 patients (15.7%); 2 required a third operation (1%). Freedom from reoperation in all patients was 97%, 83%, and 73% at 1, 5, and 10 years, respectively. Accessory mitral valve tissue (P < .001) and age <3 months (P = .004) predicted the need for reoperation. Transient or permanent high-degree AVB was documented in 33 of 185 patients (17.8%). Complex anatomy (P = .01) and aggressive resection (P < .001) increased the risk of acquiring AVB. The AVB was permanent in 21 of 185 (11.4%) patients, and pacemaker implantation was undertaken in 20 of 185 (10.8%) patients. Complex anatomy (P = .04) and modified Konno procedure (P = .03) increased the risk of acquiring a pacemaker. Aggressive resection lowered the frequency of recurrence but increased the risk of AVB. When aggressive resection is considered for long-term relief of subaortic obstruction, the risk of reobstruction must be balanced with the risk of AVB and the need for pacemaker implantation.

‘2’ much mitral tissue

A 73-year-old female patient was referred for evaluation after suffering an atypical chest pain. Physical examination and ECG were normal. The echocardiogram showed a normal ventricular function. Attached to the anterior leaflet an accessory mitral valve tissue was identified. In systole, this mitral tissue creates an image that looks like the 'number 2'.

Accessory Mitral Valve Tissue: A Case Report and an Updated Review of Literature

Accessory mitral valve tissue is an unusual congenital cardiac anomaly and a rare cause responsible for left ventricular outflow tract obstruction. An 18-year-old patient was referred to this hospital due to an occasionally noted heart murmur in a medical examination. Echocardiography facilitated the diagnosis of accessory mitral valve tissue. To relieve the left ventricular outflow tract obstruction, an operation including resection of the accessory mitral valve tissue, implantation of artificial chordae tendineae, and mitral valve annuloplasty was performed successfully. Postoperative echocardiography showed a complete relief of the mitral valve leaflets and a wide patent left ventricular outflow tract. However, transient ischemic attack and Horner's syndrome complicated the patient early postoperatively. He was administered with a high dose of aspirin, and he recovered shortly. Surgical removal is in so much mandatory as a definite diagnosis of accessory mitral valve tissue with left ventricular outflow tract obstruction is established. A prophylactic treatment should be applied to the patients with accessory mitral valve tissue in virtue of their susceptibility to neurological events.