Skip to main content

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

Abstract

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.

Background

Accessory mitral valve tissue (AMVT) is a rare congenital cardiac anomaly. This anomaly is mainly diagnosed in the first decade of life, but it may remain undiagnosed until adulthood [1]. A large proportion of patients with AMVT are asymptomatic and diagnosed incidentally. However, symptomatic patients present with chest pain, dyspnea or arrhythmias. The most serious concern in AMVT is left ventricular outflow tract (LVOT) obstruction that usually requires surgical intervention [2]. To the best of our knowledge, prenatal diagnosis of AMVT has not been previously described. Here, we present a case of non-obstructive AMVT in a fetus of the second trimester that was referred for the assessment of dysrhythmia.

Case presentation

A 30-year-old pregnant woman (gravid 2, abortion 1 and non-consanguineous marriage) was referred to us at 26 weeks of gestation because of her fetus dysrhythmia. Extrasystoles of bigeminy premature ventricular contractions (PVCs) were the cause of dysrhythmia (Fig. 1). In addition, a contractile outpouching of 7 mm × 10 mm was found in the left ventricular apex (Fig. 2). It was diagnosed as a diverticulum due to its synchronized contraction with the main left ventricular chamber. The diverticulum was connected with a broad neck to the left ventricle and had a low-velocity color flow in it (Additional file 1: Video S1). Given the persistent fetal dysrhythmia, sotalol 80 mg twice a day was initiated for the mother. In the fetal screening examination, no additional extracardiac anomaly was reported. No evidence of cardiac failure or hydrops was noted either. At 32 weeks of gestation, follow-up echocardiography revealed persistent dysrhythmia as PVCs in more than 50% of the time of the test. The LV systolic function and ventricular myocardial performance index were within the normal limits. Hence, it was decided not to continue sotalol. Moreover, an AMVT was identified below the main mitral valve with two leaflets connected to the same papillary muscles by separate chordae tendineae. Leaflets movement and E/A ratio in pulse wave Doppler were similar to the main mitral valve Doppler tracing. Accessory and main mitral valve diameter at the age of 35 weeks of gestation were 6.8 mm and 6.7 mm, respectively. Both valves had simultaneous phases of movement. There was no evidence of valvar regurgitation and LVOT obstruction. The mother's past medical history was unremarkable. She did not report the consumption of any teratogenic drugs or being affected by any viral infections during gestation. Fetal growth scans were normal in the course of pregnancy, and hydrops did not occur either. A baby girl with an Apgar score of 9 and birth weight of 3.1 kg was born at the age of 39 weeks by normal vaginal delivery. She was transferred to NICU for further work-up and monitoring. The electrocardiographic (ECG) tracing after birth was in normal sinus rhythm without any evidence of dysrhythmia. Post-delivery echocardiography confirmed the presence of accessory mitral valve, while the LV apical diverticulum faded away. At 4-month follow-up the infant was free of arrhythmia and LVOT obstruction. She was treated with aspirin, and periodic follow-up was recommended.

Fig. 1
figure 1

The pulsed Doppler sample gate was placed to include the outflow and inflow of the left ventricle. It shows the occurrence of frequent premature ventricular contractions (PVCs) with the full compensatory pauses and the first part being in a bigeminy pattern

Fig. 2
figure 2

Four chamber view of the heart showing the accessory mitral valve tissue (AMVT) and the outpouching of left ventricular diverticulum (LVD) at 26 weeks of gestation

Discussion

Accessory mitral valve tissue as a rare pathology has been reported to have an estimated incidence of 1 out of 26,000 adults [1]. With reporting our case as the prenatal diagnosis of this anomaly, one might claim that AMVT could be an echocardiographic finding from fetal to late adulthood period. Despite the miniaturized anatomy of the fetal heart, the quality and resolution of the fetal echocardiographic images have been remarkably improved since the introduction of this imaging modality [3]. With ongoing evolution in technology, the diagnosis of delicate structural heart defects such as AMVT in the fetus has become possible. Both three-dimensional (3D) and four-dimensional (4D) echocardiography enable to depict a more precise anatomical structure and provide en face visualization of the mitral valve. However, 3D and 4D fetal cardiac imaging require technical expertise [4, 5]. Likewise, although fetal cardiac magnetic resonance imaging has been used as a research tool, its clinical application in fetal heart diagnostic imaging has several limitations [3, 6].

The association of AMVT with other congenital cardiac defects has been frequently reported in the literature [1, 2, 7, 8]. This association might be attributed to the developmental pathophysiology of AMVT in the embryonic period. Normally, the endocardial cushion forms the mitral valve. If this embryonic process fails to develop normally, then AMVT might be separated from the cushion [9]. Major associated anomalies such as ventricular and atrial septal defects, atrial septal aneurysm and subaortic stenosis also originate from the defects in the endocardial cushion development [8].

Several classifications have been used to describe the shape of AMVT in different case series [8,9,10,11]. The shape is dependent on the site where AMVT is attached. The site of attachment is on the left-sided heart structures including the anterior and posterior leaflets of the mitral valve, aortic valve, papillary muscles, chordae tendineae, interventricular septum and the left atrial/ventricular walls. For a more precise anatomical description of the lesion, Prifti et al. proposed a classification system [10]. In this system, the accessory valves are divided into two shapes of fixed and mobile types. Fixed types (type I) include nodular (IA) and membranous (IB) accessory valves. Mobile type (type II) is also divided into two groups of pedunculated (IIA) and leaflet likes (IIB) accessory valves. Type IIB is further subdivided as rudimentary or well-developed chorda tendineae. Our case seems to be classified in the subdivision of IIB2 because of its mobile leaflets and well-developed chordae. A simpler classification method by Yetkin et al. [11] uses the true mitral valve leaflets as the primary landmarks for the AMVT typing. In this classification, the three types of I, II and III are described according to the attachments above, on or below the true mitral valve leaflets, respectively.

One-third of the patients with AMVT are asymptomatic. Symptoms of palpitation, chest pain, syncope and dyspnea have been reported. Patients with LVOT obstruction might experience dizziness and exertional dyspnea [8]. Other serious, however, uncommon complications are hemiplegia, transient ischemic attack and retinal artery occlusion due to thromboembolic events [11,12,13]. Dysrhythmia including atrial fibrillation and ventricular tachycardia has been reported too [8, 11]. The prenatal presentation of ventricular extrasystoles in our fetus might be attributed to the AMVT. Anomalies of the conduction system have been reported in cases of AMVT [14]. However, the co-existence of extrasystoles and AMVT in our case seems to be irrelevant because of the disappearance of both premature beats and LV apical diverticulum in post-partum echocardiograms [15, 16]. The ventricular ectopy and arrhythmia have been reported with LV wall defects including LV diverticulum. Moreover, there are reports of spontaneous fading of ventricular diverticulum before and after delivery [17]. Concomitant disappearance of extrasystoles and diverticulum in our patient's follow-up might be a clue for their cause and effect relationship.

Some studies have reported that AMVTs might be overlooked in the echocardiographic examination for other cardiac anomalies, and even some cases of AMVT have been detected years after cardiac surgery. Hence, it is advised to improve echocardiographic imaging especially in the field of fetal echocardiography by optimizing image quality in different aspects of probe resolution, probe position, transducer pressure, depth and sector width.

Clinical assessment of patients is necessary for choosing the treatment in patients with AMVT. In asymptomatic patients without any associated conditions, only follow-up is recommended. However, in symptomatic patients, multiple factors including the symptoms, obstruction of the LVOT, valvar disease, heart failure and the concomitant anomalies must be considered in the therapeutic approach [8]. Antiplatelet therapy has been suggested in all patients with AMVT [13]. Surgery is a choice with relatively vague indications in the literature. Overall, surgical resection is indicated in symptomatic patients or those with prominent LVOT obstruction [1, 8].

Conclusions

The AMVT is a rare cardiac anomaly which could be diagnosed in prenatal period in association with other structural cardiac anomalies such as ventricular diverticulum or presented as fetal dysrhythmia including ventricular premature beats.

Availability of data and materials

Please contact the corresponding author for data requests.

Abbreviations

AMVT:

Accessory mitral valve tissue

ECG:

Electrocardiography

LV:

Left ventricle

LVOT:

Left ventricular outflow tract

PVC:

Premature ventricular contraction

References

  1. Okafor J, Kanaganayagam GS, Patel K (2020) A rare finding of giant accessory mitral valve tissue: a case report. Eur Heart J Case Rep 4:1–4. https://doi.org/10.1093/ehjcr/ytz244

    Article  PubMed  PubMed Central  Google Scholar 

  2. Yuan SM, Shinfeld A, Mishaly D, Haizler R, Ghosh P, Raanani E (2008) Accessory mitral valve tissue: a case report and an updated review of literature. J Card Surg 23:769–772. https://doi.org/10.1111/j.1540-8191.2008.00633.x

    Article  PubMed  Google Scholar 

  3. Donofrio MT, Moon-Grady AJ, Hornberger LK, Copel JA, Sklansky MS, Abuhamad A, Cuneo BF, Huhta JC, Jonas RA, Krishnan A, Lacey S, Lee W, Michelfelder EC, Rempel GR, Silverman NH, Spray TL, Strasburger JF, Tworetzky W, Rychik J (2014) Diagnosis and treatment of fetal cardiac disease. Circulation 129:2183–2242. https://doi.org/10.1161/01.cir.0000437597.44550.5d

    Article  PubMed  Google Scholar 

  4. Hamill N, Yeo L, Romero R, Hassan SS, Myers SA, Mittal P, Kusanovic JP, Balasubramaniam M, Chaiworapongsa T, Vaisbuch E (2011) Fetal cardiac ventricular volume, cardiac output, and ejection fraction determined with 4-dimensional ultrasound using spatiotemporal image correlation and virtual organ computer-aided analysis. Am J Obstet Gynecol 205:76.e71-76.e10

    Article  Google Scholar 

  5. Sklansky MS, Nelson TR, Pretorius DH (1998) Three-dimensional fetal echocardiography: gated versus nongated techniques. J Ultrasound Med 17:451–457

    CAS  Article  Google Scholar 

  6. Manganaro L, Savelli S, Di Maurizio M, Perrone A, Tesei J, Francioso A, Angeletti M, Coratella F, Irimia D, Fierro F (2008) Potential role of fetal cardiac evaluation with magnetic resonance imaging: preliminary experience. Prenat Diagn Publ Affil Int Soc Prenat Diagn 28:148–156

    Google Scholar 

  7. Bilal MS, Oztunç F, Beşikçi R, Bilal S, Ozkara A, Olga R (1999) Accessory mitral valve tissue causing severe subaortic stenosis with dextrocardia in a premature newborn. Thorac Cardiovasc Surg 47:252–255. https://doi.org/10.1055/s-2007-1013154

    CAS  Article  PubMed  Google Scholar 

  8. Manganaro R, Zito C, Khandheria BK, Cusmà-Piccione M, Chiara Todaro M, Oreto G, D’Angelo M, Mohammed M, Carerj S (2014) Accessory mitral valve tissue: an updated review of the literature. Eur Heart J Cardiovasc Imaging 15:489–497. https://doi.org/10.1093/ehjci/jet163

    Article  PubMed  Google Scholar 

  9. Panduranga P, Eapen T, Al-Maskari S, Al-Farqani A (2011) Accessory mitral valve tissue causing severe left ventricular outflow tract obstruction in a post-Senning patient with transposition of the great arteries. Heart Int 6:e6. https://doi.org/10.4081/hi.2011.e6

    Article  PubMed  PubMed Central  Google Scholar 

  10. Prifti E, Bonacchi M, Bartolozzi F, Frati G, Leacche M, Vanini V (2003) Postoperative outcome in patients with accessory mitral valve tissue. Med Sci Monit 9:Ra126–133

    PubMed  Google Scholar 

  11. Yetkin E, Cuglan B, Turhan H, Yalta K (2021) Accessory mitral valve tissue: anatomical and clinical perspectives. Cardiovasc Pathol 50:107277. https://doi.org/10.1016/j.carpath.2020.107277

    Article  PubMed  Google Scholar 

  12. Yetkin E, Turhan H, Atak R, Senen K, Cehreli S (2003) Accessory mitral valve tissue manifesting cerebrovascular thromboembolic event in a 34-year-old woman. Int J Cardiol 89:309–311. https://doi.org/10.1016/s0167-5273(02)00511-9

    Article  PubMed  Google Scholar 

  13. Turhan H, Yetkin E (2009) A potential source of cardioembolic cerebrovascular event: accessory mitral valve tissue. Int J Cardiol 133:e57. https://doi.org/10.1016/j.ijcard.2007.11.011

    Article  PubMed  Google Scholar 

  14. Golias C, Bitsis T, Krikidis D, Charalabopoulos K (2012) Accessory mitral valve without subaortic obstruction of left ventricular outflow tract in a middle-aged male. BMJ Case Rep 2012:bcr2012006949. https://doi.org/10.1136/bcr-2012-006949

    Article  PubMed  PubMed Central  Google Scholar 

  15. Pradhan M, Dalal A, Kapoor A, Kumar S, Manisha R (2008) Fetal left ventricular diverticulum presenting as dysrhythmia: diagnosis and management. Fetal Diagn Ther 23:10–14. https://doi.org/10.1159/000109219

    Article  PubMed  Google Scholar 

  16. Perlitz Y, Mukary M, Lorber A, Ben-Ami M (2009) Prenatal diagnosis of fetal cardiac right ventricular diverticulum disappearing at three months of age. A case report and literature review. Fetal Diagn Ther 25:44–46. https://doi.org/10.1159/000196815

    Article  PubMed  Google Scholar 

  17. Brucks U, Duval J, Roberson D, Cuneo B, Husayni T (2008) Fetal bifid left ventricular diverticulum presenting with ventricular ectopy. J Diagn Med Sonogr 24:165–168. https://doi.org/10.1177/8756479308317003

    Article  Google Scholar 

Download references

Acknowledgements

Not applicable.

Funding

Not applicable.

Author information

Authors and Affiliations

Authors

Contributions

All authors effectively contributed to different parts of manuscript preparation including conceptualization, writing original draft, reviewing and editing the manuscript and supervision of intellectual content. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Reza Shabanian.

Ethics declarations

Ethics approval and consent to participate

This article does not contain any studies with human participants performed by any of the authors.

Consent for publication

Written informed consent was obtained from the patient for publication of this case report and accompanying images.

Competing interests

The authors declare that they have no competing interests.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Additional file 1: Video S1. 2D and color Doppler four chamber view of the heart showing type IIB2 accessory mitral valve tissue (AMVT) and the synchronous left ventricular diverticulum (LVD) contraction with the main LV chamber at 26 weeks of gestation.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Hematian, M.N., Torabi, S., Hantoushzadeh, S. et al. Prenatal diagnosis of accessory mitral valve tissue in a fetus with persistent dysrhythmia. Egypt Heart J 74, 26 (2022). https://doi.org/10.1186/s43044-022-00263-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s43044-022-00263-z

Keywords

  • Accessory mitral valve tissue
  • Diverticulum
  • Fetal echocardiography
  • Dysrhythmia
  • Extrasystole