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

A case of percutaneous septal myocardial ablation in a patient with obstructive hypertrophic cardiomyopathy with accessory mitral valve tissue

Accessory mitral valve tissue (AMVT) is a rare congenital anomaly that sometimes causes left ventricular outflow tract (LVOT) obstruction. We report the case of a 72-year-old woman with hypertrophic obstructive cardiomyopathy (HOCM) complicated by AMVT. The patient presented at our hospital with palpitations and shortness of breath. Transthoracic echocardiography revealed a diagnosis of HOCM and an abnormal structure inside the LVOT. Transesophageal echocardiography revealed an AMVT. We initially treated the patient with oral medication, but due to side effects, the patient could not take the target dose and her symptoms did not improve. We suggested surgical treatment, but the patient refused. By evaluating the relationship between AMVT and the surrounding tissues using three-dimensional transesophageal echocardiography, we determined that percutaneous septal myocardial ablation (PTSMA) might be successful. The first PTSMA was not effective, but the second procedure showed significant improvement in the pressure gradient and symptoms. The patient with HOCM and concomitant AMVT had a severe LVOT pressure gradient, and PTSMA was performed with excellent results. Since we experienced a rare case and were able to treat it percutaneously, we report our findings in relation to the literature.

Learning objective

This case study highlights successful use of percutaneous septal myocardial ablation (PTSMA) in treating a patient with hypertrophic obstructive cardiomyopathy (HOCM) and accessory mitral valve tissue (AMVT). The key objective is to understand PTSMA can be an effective treatment option for HOCM with Type IIa AMVT, characterized by the attachment only to the mitral leaflets, when surgical intervention is not preferred, enhancing management of this rare condition.

Hypertrophic obstructive cardiomyopathy with left ventricle outflow tract chordae insertion: Surgery or alcohol septal ablation? A case report

Anomalous insertion of chordae is a rare disease that could be associated with hypertrophic obstructive cardiomyopathy (HOCM), but clinical and echocardiographic diagnoses tend to be delayed. Alcohol septal ablation has emerged as an alternative to surgical myomectomy in HOCM. When a patient showed an anomalous insertion of chordae, physicians generally opt for surgery and not alcohol septal ablation. In this report, we present the case of a lady, with symptomatic HOCM associated with a chord inserted on the left ventricular outflow tract. We succeeded to relieve obstruction by alcohol septal ablation without the need for surgery.

Incidental detection of accessory mitral valve in adolescent with atrial septal defect: Diagnosis with 3D transesophageal echocardiography and excision with transaortic method

BACKGROUND

Accessory mitral valve tissue (AMVT) is an extremely rare causes left ventricular outflow tract (LVOT) obstruction and is usually incidentally detected in childhood. It is often associated with other cardiac and vascular congenital malformations.

CASE PRESENTATION

In this case, we present a 15-year-old girl was diagnosed with AMVT by transesophageal echocardiography, resulting in LVOT obstruction during systole. Interestingly enough, the patient's accessory mitral valve remained undetected for years until he became symptomatic for wide ASD. Successful closure of the ASD with resection of the AMVT was performed with a transaortic approach. The patient was hemodynamically stable postoperatively. There were no abnormalities in the mitral valves and LVOT.

CONCLUSION

It was also unusual to see AMVT with ASD instead of other frequently associated other congenital anomalies. Accessory mitral valve should be considered a rare but important cause of left ventricular outflow tract obstruction in childhood.

Accessory Mitral Valve Tissue and Internal Mammary Artery Stenosis

A man with recurrent syncope and remote aortic coarctation repair experienced cardiac arrest with exercise stress testing. Critical coronary stenosis was discovered. Further evaluation revealed accessory mitral valve tissue and internal mammary artery occlusion. These rare abnormalities, not previously reported together, presented challenges to treatment. (Level of Difficulty: Intermediate.)

Incidental finding of accessory mitral valve tissue on routine adult echocardiography

Accessory mitral valve tissue is a rare congenital cardiac abnormality that sometimes can cause left ventricular outflow tract obstruction. We herein present the case of a 55-year-old male with an incidental finding of accessory mitral valve tissue on transthoracic echocardiography. The patient was managed conservatively as accessory tissue was not causing left ventricular outflow obstruction and there were no hemodynamic consequences.

Echocardiographic features of accessory mitral valve tissue presenting left ventricular outflow tract obstruction in a dog

In a 3-year-old Samoyed, aortic bulging was found on radiography during a general check-up. On echocardiography, turbulent flow was found in left ventricular outflow tract (LVOT) with high velocity (6.1 m/s). A linear structure was attached to the interventricular septum and connected to the chordae tendineae reaching the papillary muscle. A part of the structure moved during cardiac cycle, similar to mitral motion. This dog was diagnosed with LVOT obstruction caused by accessory mitral valve tissue (AMVT). This is the first report of AMVT in veterinary medicine. AMVT should be considered as a possible cause of LVOT obstruction in dogs.

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.

Parachute Mitral Valve: A Case of Isolated Accessory Mitral Valve Tissue

A 69-year-old male presented to the emergency room with dyspnea on exertion lasting more than 2 weeks. Echocardiography showed an ill-defined subaortic structure. Subsequent transesophageal echocardiography revealed a parachute-like structure prolapsing into the left ventricular outflow tract causing subvalvular aortic obstruction. Surgical excision confirmed this structure as an accessory anterior mitral leaflet. (Level of Difficulty: Intermediate.).

Accessory mitral valve tissue that caused a left ventricular outflow tract obstruction: a case report

BACKGROUND

Accessory mitral valve tissue (AMVT) is a rare congenital cardiac anomaly and is usually diagnosed in childhood. The diagnosis of AMVT in adulthood is extremely rare. We present a case report on an adult patient with AMVT that caused a left ventricular outflow tract (LVOT) obstruction.

CASE PRESENTATION

A 51-year-old man was diagnosed with AMVT via transesophageal echocardiography, which resulted in an LVOT occlusion (mean gradient 12 mmHg) during systole. Resection of the AMVT was performed under general anesthesia. The patient was hemodynamically stable throughout the surgery and post-operation. There was no abnormity of the mitral valves, including mitral regurgitation.

CONCLUSIONS

Although a very rare malformation, particularly in adults, AMVT can cause LVOT obstruction. Examination of the mitral valve using transesophageal echocardiography is important to understand the severity of LVOT obstruction.

An Extremely Rare Cause of Mitral Regurgitation-Accessory Commissural Mitral Tissue with Anomalous Left Atrial Chordal Attachment

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Accessory mitral tissue and left atrial chordae are rare congenital abnormalities.

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Accessory mitral tissue can result in left ventricular outflow tract and mitral valve obstruction.

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This is the first case of lateral mitral accessory tissue with an associate anomalous chord.

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Transthoracic echocardiography may not be able to evaluate accessory mitral valve tissue.

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Removal of anomalous chordae affecting the mitral valve may be complicated.

Obstructive accessory mitral valve tissue in an adult patient: a case report

Background

Accessory mitral valve tissue is a rare congenital anomaly that is commonly diagnosed in early childhood and rarely in adulthood. It is usually asymptomatic. However, it may cause left ventricular outflow tract obstruction in a way that mimics various other causes of obstruction.

Case summary

A 72-year-old Caucasian man complained of chest discomfort and exertional dyspnea for 3 months. There were no specific findings from a physical examination except systolic murmur. Transthoracic echocardiography demonstrated a mass on the mitral valve extending to the intraventricular septal, raising the pressure gradient flow across the aortic valve. Transesophageal echocardiography showed parachute-like tissue connected to the anterior leaflet of the mitral valve causing left ventricular outflow tract obstruction. During the surgery preparation period, he underwent coronary angiography and computed tomography to study the anatomy surrounding the mass. After surgery, biopsy showed non-specific findings.

Conclusion

When facing a case of aortic valve stenosis, accessory mitral valve tissue should be kept in mind as one of the possible underlying causes despite its rarity. Although it is simple and noninvasive, echocardiography remains the best diagnostic procedure to make the correct decision about management and to define the golden time for surgical intervention.

Electronic supplementary material

The online version of this article (10.1186/s13256-019-2110-z) contains supplementary material, which is available to authorized users.

A rare case of accessory mitral valve tissue causing left ventricular outflow tract obstruction associated with parachute mitral valve, ventricular septal defect, bicuspid aortic valve, unruptured aneurysm of aortic sinus: a case report

Background

Accessory mitral valve tissue rarely causes left ventricular outflow tract obstruction in adults. It is often associated with other cardiac and vascular congenital malformations. Here, we report the rarest presentation of accessory mitral valve tissue (AMVT) causing left ventricular outflow tract obstruction.

Case summary

A 22-year-old female patient presented with a history of shortness of breath and chest pain for more than 5 years. A diagnosis of AMVT with parachute mitral valve, ventricular septal defect (VSD), bicuspid aortic valve, unruptured aneurysm of aortic sinus, and left ventricular outflow tract obstruction was made. Successful closure of VSD with mitral valve replacement, excision of AMVT, and repair of the aortic sinus were performed. The post-operative course was uneventful, and an echocardiogram showed complete resection of the accessory mitral valve, no residual shunt and no left ventricular outflow gradient. Additionally, the peak gradient of rapid filling phase and atrial systolic phase across the prosthetic mitral valve were 16 mmHg and 4 mmHg, respectively. The peak velocity across left ventricular outflow tract was 1.4 m/s.

Discussion

Accessory mitral valve tissue is associated with other cardiac abnormalities and is usually diagnosed in the first or second decade of life. It is responsible for left ventricular outflow tract obstruction. The obstruction can occur in the early period of life due to continued deposition of fibrous tissues within left ventricular outflow tract. Accessory mitral valve tissue should be considered a rare but important cause of left ventricular outflow tract obstruction.

Transaortic accessory mitral valve excision in an adult patient: Case report

Accessory mitral valve tissue is a rare congenital cardiac anomaly, and is usually incidentally detected in childhood. In this case, we present a 65-year-old man with aortic stenosis originating from an accessory mitral valve leaflet attached to the anterior mitral leaflet. Interestingly enough, the patient's accessory mitral valve remained undetected for years until he became symptomatic for degenerative aortic stenosis. Aortic valve replacement and excision of the accessory mitral valve attached to the anterior mitral leaflet was performed with a transaortic approach instead of atriotomy. It was also unusual to see accessory mitral valve tissue with aortic stenosis instead of other frequently associated congenital anomalies.

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.

Acute Multiple Cerebral Infarction in a Patient with an Accessory Mitral Valve

A 96-year-old woman developed hemiparesis 2 weeks after orthopedic surgery. Magnetic resonance imaging revealed multiple cerebral infarctions in the bilateral hemisphere. Transthoracic echocardiography revealed a mobile structure attached to the anterior mitral leaflet that protruded toward the left ventricular outflow tract. The structure was identified as an accessory mitral valve. Doppler echocardiography showed that there was no significant left ventricular outflow obstruction. This is a rare case of a silent accessory mitral valve that was detected after multiple cerebral infarctions.

Jellyfish-Like Accessory Mitral Valve Tissue Causing Near-Collapse in a Young Child

Accessory mitral valve tissue (AMVT) causing left ventricular outflow tract obstruction (LVOTO) is rare. We report a case of AMVT causing severe LVOTO resulting in acutely progressive symptoms of near-collapse. Urgent surgical resection eliminated the patient's life-threatening symptoms. AMVT should be considered among potential LVOTO diagnoses, and early surgical intervention may be required.

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.

Robotic resection of dual accessory mitral valve tissue in an adult patient

The presence of isolated accessory mitral valve tissue (AMVT) is extremely rare in adults. We successfully performed robot-assisted resection of dual AMVT that was attached to the papillary muscle and anterior mitral leaflet. Echocardiography was invaluable for identifying the most suitable approach. The short-axis view on echocardiography revealed the precise location where the AMVT was attached. The robotic operation enabled fine visualization; we clearly observed the AMVT and removed its entire extra structure. The patient recovered well and was discharged 3 days after the operation. To the best of our knowledge, this is the first report of successful robotic AMVT resection.

Asymptomatic and isolated accessory mitral valve tissue in an adult

Accessory mitral valve (AMV) tissue is a congenital anomaly that occurs in association with other congenital anomalies, and is an uncommon cause of left ventricular outflow tract obstruction. It is usually detected in early childhood when accompanied by symptoms of obstruction of the left ventricular outflow tract, and is rarely diagnosed in adults. We present a case of a 53-year-old man who was referred to our institution for evaluation of a systolic heart murmur. Echocardiography disclosed a diagnosis of AMV tissue. This case was uncommon because of the lack of severe obstruction of left ventricular outflow, cardiac symptoms, or other cardiac anomalies. We were able to carry out surgical resection of AMV tissue to avert possible progression of aortic insufficiency and the risk of a cerebrovascular embolization. The patient's postoperative course was uneventful, and postoperative echocardiography showed no residual accessory mitral tissue.

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.

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.

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.

Accessory mitral valve associated with transient ischemic attacks

Accessory mitral valve (AMV) is an unusual congenital cardiac anomaly typically presenting with left ventricular outflow obstruction. We describe a patient with AVM presenting with transient ischemic attack. 

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.

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.

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.

Accessory mitral valve as a potential source of cardioembolism

An accessory mitral valve (AMV) is considered to arise from abnormal development of endocardial cushion tissue. It is a very rare entity, commonly diagnosed in childhood and associated with symptomatic left ventricular outflow tract (LVOT) obstruction. Here we describe the presence of AMV in a 58-year old patient who presented with a transient ischemic attack. Transesophageal echocardiography visualized a spherical structure attached to the ventricular aspect of the anterior mitral valve leaflet.

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.