Clinical and pathological features of accessory valve tissue

A Redundant Tricuspid Valve Leaflet in a 23-Year-Old Female: A Report of a Rare Case and a Literature Review

Accessory tricuspid valve (ATV) is a rare cardiac anomaly often associated with other complex cardiac disorders, most commonly tetralogy of Fallot (TOF) and ventricular septal defect (VSD), but it can also be an isolated entity. It is usually diagnosed in childhood. It can be asymptomatic and get diagnosed incidentally, but it can also lead to cardiac complications such as right ventricular outflow obstruction (RVOTO) or tricuspid valve regurgitation. Here, we present the case of a 23-year-old woman with an isolated ATV diagnosed on an echocardiogram without symptoms after a physical exam noted a murmur, with a subsequent echocardiogram showing moderate to severe tricuspid valve regurgitation. A literature review was also performed. Only a small number of ATV cases have been reported, most of them diagnosed in childhood and associated with other congenital cardiac anomalies. Most of the cases necessitated surgical intervention, with a portion resulting in fatalities. It is important to understand the diagnosis and morphology of the ATV due to its association with dangerous complications to guide the management of this entity. It is also important to conduct further research to understand the inheritance of this pathology and develop screening and prevention plans.

Accessory mitral valve tissue: anatomical and clinical perspectives

Mitral valve is a complex cardiac structure composed of several components to work in synchrony to allow blood flow into left ventricle during diastole and not to allow blood flow into left atrium during systole. Accessory mitral valve tissue (AMVT) was defined as existence of any additional part and parcel of valvular structure which has an attachment to normal mitral valve apparatus in left-sided cardiac chambers. AMVT may present itself in different clinical circumstances ranging from a silent clinical course to thromboembolic events, heart failure, left ventricular outflow tract obstruction, and severe arrhythmia. This article reviews the clinical perspectives of AMVT in terms of symptoms, diagnosis, and treatment, providing a new anatomical classification regarding the location of AMVT. Briefly type I refers to AMVT having attachments on the supra leaflets level, type II refers to attachments on the mitral leaflets, and type III refers to attachment below the mitral leaflets. Increased awareness and widespread use of echocardiographic techniques would increase recognition of AMVT in patients with heart murmurs but otherwise healthy and in those with left ventricular outflow tract obstruction or tissue which causes subaortic stenosis and with unexplained cerebrovascular events.

A rare finding of giant accessory mitral valve tissue: a case report

Background

Accessory mitral valve tissue (AMVT) is a rare anomaly that can be detected in the first decade. It is associated with other congenital cardiac abnormalities, such as ventricular septal defect. When detected in adulthood, it is usually an incidental finding on echocardiography. Symptomatic individuals can present with breathlessness, syncope, and features of distal tissue embolization. Cardiac surgery is indicated in those with significant left ventricular outflow tract obstruction.

Case summary 

A 45-year-old man without any significant medical history was referred due to an abnormal electrocardiogram. He was asymptomatic from a cardiac perspective. Echocardiography revealed the presence of a giant mobile mass attached to the anterior mitral valve leaflet and prolapsing into the left ventricular outflow tract (LVOT). This was classified as Type IIB2 AMVT. As there was no dynamic outflow tract obstruction on subsequent treadmill stress echocardiography, and in the absence of other coexistent congenital abnormality, surgical excision was not performed.

Discussion 

It is important to exclude significant obstruction when a large AMVT is seen to be prolapsing into the LVOT. Three-dimensional echocardiography is the tool of choice for anatomical classification and to assess for concomitant congenital cardiac abnormalities.

A rare cause of retinal artery embolism: Accessory mitral valve tissue

A 42-year-old female patient was referred our clinic for investigation of a history of acute retinal artery occlusion. Transthoracic echocardiography showed a cyst-like, mobile formation on posterior mitral valve leaflet. 2D and real time 3D transesophageal echocardiography showed a flexible circular mobile structure which was attached to posterior mitral valve leaflet. Echocardiographic appearance and morphological characteristics were suggestive of accessory mitral valve tissue.

Accessory Mitral Valve Tissue Obstructing Left Ventricular Outflow Tract

A 6-year-old girl underwent surgical excision of accessory mitral valve tissue causing significant subaortic stenosis. Preoperative 2-dimensional echocardio-graphy gave the necessary information on this isolated anomaly. The approach through an aortotomy provided adequate exposure. Postoperatively, there was no residual gradient across the left ventricular outflow tract, or mitral regurgitation.

Bands, Chords, Tendons, and Membranes in the Heart: An Imaging Overview

Crests, bands, chords, and membranes can be seen within the different cardiac chambers, with variable clinical significance. They can be incidental or can have clinical implications by causing hemodynamic disturbance. It is crucial to know the morphology and orientation of normal structures, aberrant or accessory muscles, and abnormal membranes to diagnose the hemodynamic disturbance associated with them. Newer generation computed tomographic scanners and faster magnetic resonance imaging sequences offer high spatial and temporal resolution allowing for acquisition of high resolution images of the cardiac chambers improving identification of small internal structures, such as papillary muscles, muscular bands, chords, and membranes. They also help in identification of other associated complications, malformations, and provide a road map for treatment. In this article, we review cross-sectional cardiac imaging findings of normal anatomical variants and distinctive imaging features of pathologic bands, chords, or membranes, which may produce significant hemodynamic changes and clinical symptomatology.

Accessory mitral valve: a rare cause of asymptomatic severe left ventricular outflow tract obstruction

Accessory mitral valve (AMV) is an extremely uncommon congenital cardiac anomaly and it is a rare cause of left ventricular outflow tract (LVOT) obstruction. Identification of asymptomatic patients with LVOT obstruction is uncommon since the symptoms usually become manifest when the gradient across the LVOT rises. We describe a rare case of asymptomatic AMV with severe LVOT obstruction in a 10-year old child with no other congenital or acquired cardiac defects who successful underwent surgery. This case emphasizes the importance of early surgical indication also in absence of symptoms when significant LVOT obstruction occurs.

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.

Abnormal mitral valve anatomy in d-transposition of the great arteries: anatomic characterization and surgical outcomes

Mitral valve anomalies can occur with S,D,D-transposition of the great arteries (d-TGA). Their influence on surgical technique and outcome after an arterial switch operation (ASO) has not been well described. Patients with d-TGA who underwent ASO from February 1990 to January 2011 were identified. Echocardiograms, operative reports, hospital course, and latest follow-up evaluation were reviewed. A total of 218 infants underwent ASO at a median age of 15.8 days. Survival was 95 % during a mean follow-up period of 60 months. Nine patients (4 %) were found to have similar mitral valve anomalies including anterior malalignment conoventricular septal defect, anterior displacement of the mitral valve toward the left ventricular outflow tract (LVOT), malpositioning of the posteromedial papillary muscle, unusual rotation of the mitral valve leaflets orienting the commissure toward the anterior ventricular septum, and redundant mitral valve tissue extending into the LVOT. Coarctation was more frequent in this subgroup (33 vs. 10 %; p = 0.05). Preoperative echocardiography consistently indicated suspicion of a cleft mitral valve with chordal attachments to the ventricular septum causing potential LVOT obstruction. Operative inspection did not identify a cleft or anomalous attachments in any patient, and no valvuloplasty or chordal manipulation was performed. The average hospital length of stay were similar (30.7 vs. 25.3 days; p = 0.54). One patient died late due to progressive LVOT obstruction, and one required heart transplantation. No patient had significant mitral valve regurgitation. We conclude that mitral valve anomalies associated with d-TGA are rare but present with consistent anatomic features and higher risk of coarctation. Unusual mitral valve apparatus positioning and chordal redundancy can suggest the need for valvuloplasty and chordal resection preoperatively, but this is rarely needed.

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.

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 causing left ventricular outflow tract obstruction

We studied the clinical characteristics and operative treatment of left ventricular outflow tract obstruction (LVOTO) caused by a congenital accessory mitral valve (AMV). Two patients were admitted to our department. Preoperatively, case 1 was diagnosed as congenital heart disease with severe LVOTO and an anterior mitral valve cleft. The patient in case 2 had a congenital atrial septal defect combined with AMV and mild LVOTO, as well as mild mitral valve regurgitation. In case 1, LVOTO was caused by a type I (fixed) AMV. In case 2, the AMV was type II (mobile type). Both AMV were resected, and the concomitant cardiac disorders were treated simultaneously. The operations were successful, and the LVOTO almost disappeared. Patients with LVOTO caused by AMV should undergo operation for removal of the accessory valve. These patients should be followed up and observed periodically by Doppler echocardiography to identify any aggravation of the LVOTO.

Isolated accessory tricuspid valve causing right ventricular outflow tract obstruction

Accessory tricuspid valve (TV) tissue is a rare congenital cardiac anomaly with varying clinical and hemodynamic features. We report a rare case of accessory TV tissue causing severe right ventricular outflow tract obstruction (RVOT) in a patient without associated cardiac anomaly. Surgical resection of the isolated accessory TV tissue resulted in complete relief of the RVOT without compromising TV function.

Accessory mitral valve in an elderly man on maintenance hemodialysis

This report describes a case of accessory mitral valve in an elderly patient on maintenance hemodialysis. Transesophageal echocardiography revealed a mobile sac-like structure with size of 12 × 10 mm(2), which attached to the left ventricular surface of base of the anterior mitral valve leaflet. Mobile stick-like structure with diameter of 21 mm was extending from this sac-like structure toward the left ventricular outflow tract and had a floating free edge. Peak pressure gradient across the left ventricular outflow tract was 32 mmHg. There were no other congenital cardiac anomalies. No clinical findings suggestive of bacterial or nonbacterial vegetation were seen. Also other possibilities of mobile thrombus or calcification were unlikely. These abnormal structures were diagnosed as accessory mitral valve with rudimentary chordae.

Accessory mitral valve causing left ventricular outflow tract obstruction in an adult

Accessory mitral valve (AMV) is a rare congenital abnormality that, rarely, causes left ventricular outflow tract (LVOT) obstruction in adults. We report the case of a 47-year-old man with deteriorating exertional dizziness. Evaluations revealed that the left ventricular outflow tract obstruction was caused by the accessory mitral valve. The patient underwent a successful operation for removal of the accessory mitral valve.

Accessory Mitral Valve in an Adult Population: The Role of Echocardiography in Diagnosis and Management

Accessory mitral valve is a rare congenital abnormality and is an unusual cause for subvalvular left ventricular outflow tract (LVOT) obstruction. It is detected first in children and is very rarely noticed in adults. The most common clinical presentation is symptomatic LVOT obstruction. We present a case series of 5 adult patients with varying clinical presentations in which the accessory mitral valve was diagnosed using echocardiography. Three patients presented with varying degrees of symptomatic LVOT obstruction, one presented with recurrent transient ischemic attack and stroke, and one patient was incidentally diagnosed during echocardiography to exclude endocarditis. Accessory mitral valve should be suggested in patients with LVOT obstruction.