Accessory mitral valve tissue: an updated review of the literature

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.

Accessory mitral valve tissue: a differential diagnosis of an obstructive mass on the left ventricular outflow tract

Accessory mitral valve tissue is a rare congenital cardiac anomaly that is typically discovered incidentally during echocardiographic evaluation prompted by an asymptomatic murmur. This pathology has characteristic echocardiographic elements and is usually associated with other CHD. The decision to perform surgical resection depends on factors such as the degree of obstruction, presence of symptoms, presence of other CHDs, and risk of thrombosis. The researchers hereby present a case of an asymptomatic paediatric patient with accessory mitral valve tissue that produced left ventricular outflow tract obstruction.

Left ventricular outflow tract obstruction caused by a congenital accessory mitral valve leaflet and treated by open-heart surgery in a young dog

A 3-month-old Shetland sheepdog presented with a loud ejection murmur and exercise intolerance. Echocardiography revealed an accessory mitral valve leaflet, characterised by a valve-like structure separate from the mitral valve seen in the subaortic region of the ventricular septum. The left ventricular outflow tract was partially obstructed with a pressure gradient of 12 mmHg. Accessory mitral valve leaflet resection and mitral valvuloplasty were performed during open-heart surgery. Histology performed on the membrane-like structures were indicative of fibrous connective tissues. Postoperative echocardiography confirmed removal of the valve-like structure with resolution of the left ventricular outflow tract obstruction. The pressure gradient was decreased to 4.6 mmHg. The dog was in good condition and no further treatment was required 5 months after surgery. Both cardiac troponin I and NT-proBNP were markedly decreased. In this dog, surgical resection combined with mitral valve plasty resolved the left ventricular outflow tract obstruction and the clinical signs.

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.

Prenatal diagnosis of accessory mitral valve tissue in a fetus with persistent dysrhythmia

Background

Accessory mitral valve tissue (AMVT) is a rare congenital cardiac anomaly that mainly diagnosed in the first decade of life. However, asymptomatic cases may not be diagnosed even up to adulthood. We report a fetus with AMVT to show the diagnostic ability of the fetal echocardiography for detection of this pathology in the prenatal period.

Case presentation

AMVT was diagnosed in a 26-week-old male fetus with persistent dysrhythmia. Dysrhythmia could not be aborted and controlled by sotalol till the third trimester evaluation. Apical left ventricular (LV) diverticulum was the additional finding in his fetal echocardiogram. After birth, he was in sinus rhythm and echocardiography confirmed the presence of AMVT, however, without any evidence of LV apical diverticulum.

Conclusions

The diagnosis of AMVT in the prenatal period is possible by fetal echocardiography.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43044-022-00263-z.

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.

Papillary muscle rupture after transcatheter aortic valve implantation

Catheter-induced mitral regurgitation (MR) caused by mitral papillary muscle rupture can be a fatal complication of transcatheter aortic valve implantation (TAVI). We report a case involving an 89-year-old man who presented with symptomatic severe aortic stenosis. In addition, preoperative echocardiography showed accessory mitral valve tissue. Although moderate MR developed immediately after TAVI, severe MR caused by anterolateral papillary muscle rupture occurred 3 months after TAVI. As only a few case series have been published, our case report adds to the evidence base for this treatment strategy.

Non-Obstructive Accessory Mitral Valve Tissue in an Asymptomatic Adult: A Case Report and Review of Literature

Accessory mitral valve tissue (AMVT) is a rare congenital cardiac anomaly that is often an asymptomatic incidental finding. However, it has also been reported to be an important cause of left ventricular outflow tract obstruction (LVOTO) in subset of patients. When symptomatic, patients can often present with symptoms, including dyspnea, chest pain and palpitations/arrhythmias. Surgical resection is indicated in symptomatic cases with significant LVOTO. We here report a 50-year-old male who presented with chest pain and was incidentally found to have AMVT on an echocardiogram. No evidence of LVOTO was seen at rest, Valsalva, or stress. We also provide a review of literature in regards to most relevant clinical implication of AMVT. 

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.).

Minimally invasive surgical repair of accessory mitral valve tissue: A case report

INTRODUCTION

Accessory mitral valve tissue is a rare congenital disease of the mitral valve. It is usually associated with other cardiac malformations and/or left ventricular outflow tract obstruction. More than 2/3 of patients were diagnosed in their childhood. Treatment can be conservative or surgical. The suitable timing for surgery remains controversial, some authors suggest early intervention to prevent devastating complications.

CASE REPORT

We report a case of an adult patient with accessory mitral valve tissue causing left ventricular outflow tract obstruction, who was treated surgically via the right minithoracotomy.

Echocardiographic Diagnosis of a Subaortic Membrane Attached to the Free Edge of the Right Coronary Cusp of the Aortic Valve

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Subaortic membranes may attach to the free edge of the aortic valve cusps.

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Subaortic membranes may occur in isolation without other congenital abnormalities.

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TEE may offer better characterization of subaortic membranes.

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.

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.

Accessory mitral valve mimicking aortic valve endocarditis as a cause of cerebrovascular accident

Accessory mitral valve (AMV) is a rare congenital cardiac malformation associated with left ventricular outflow tract obstruction and endocarditis. We report a patient with an AMV who presented with a cerebellar infarct and discuss the management of this anomaly.

Accessory Mitral Valve Leaflet Causing Severe Left Ventricular Outflow Tract Obstruction in a Preterm Neonate with a Partial Atrioventricular Septal Defect

Atrioventricular septal defects represent a class of congenital cardiac malformations that vary in presentation and management strategy depending upon the severity of the particular lesions present. We present the case of a premature neonate who had a partial atrioventricular septal defect and an accessory mitral (or left atrioventricular) valve leaflet. The latter caused severe left ventricular outflow tract obstruction and severely depressed left ventricular function. We found only one other report of this atrioventricular valve abnormality in association with atrioventricular septal defect. To our knowledge, our patient (at a body weight of 1,800 g) is the smallest to survive corrective surgery of an accessory mitral valve leaflet with severe left ventricular outflow tract obstruction. In addition to our patient's case, we discuss the relevant medical literature.

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.

The year 2014 in the European Heart Journal--Cardiovascular Imaging: part II

The European Heart Journal-Cardiovascular Imaging, created in 2012, has become a reference for publishing multimodality cardiovascular imaging scientific and review papers. The impressive 2014 impact factor of 4.105 confirms the important position of our journal. In this part, we summarize the most important studies from the journal's third year, with specific emphasis on cardiomyopathies, congenital heart diseases, valvular heart diseases, and heart failure.