Journal of The Indian Academy of Echocardiography & Cardiovascular Imaging

INTERESTING CASE REPORT
Year
: 2019  |  Volume : 3  |  Issue : 3  |  Page : 185--188

Atypical Presentation of Typical Parachute-Like Asymmetrical Mitral Valve


Pratap Chandra Rath1, Md Abdul Azeez Asad1, B. V. A. Ranga Reddy1, Monica Vinesh Dillikar1, C. Rajesh Reddy2,  
1 Department of Cardiology, Apollo Hospital, Hyderabad, Telangana, India
2 Department of Neurology, Apollo Hospital, Hyderabad, Telangana, India

Correspondence Address:
Monica Vinesh Dillikar
Apollo Hospital, Jubilee Hills, Hyderabad, Telangana
India

Abstract

Parachute and parachute-like mitral valve are extremely rare congenital anomalies of mitral valve involving multiple aspects of mitral valve apparatus. It is usually seen in the younger age group. Very few cases of isolated parachute-like mitral valve in the adult age group have been in the literature. We hereby present a case report of 70-year-old elderly man who had presented with recurrent stroke and a routine transthoracic echocardiography had revealed a classical description of asymmetrical mitral valve.



How to cite this article:
Rath PC, Asad MA, Reddy BV, Dillikar MV, Reddy CR. Atypical Presentation of Typical Parachute-Like Asymmetrical Mitral Valve.J Indian Acad Echocardiogr Cardiovasc Imaging 2019;3:185-188


How to cite this URL:
Rath PC, Asad MA, Reddy BV, Dillikar MV, Reddy CR. Atypical Presentation of Typical Parachute-Like Asymmetrical Mitral Valve. J Indian Acad Echocardiogr Cardiovasc Imaging [serial online] 2019 [cited 2020 Jun 6 ];3:185-188
Available from: http://www.jiaecho.org/text.asp?2019/3/3/185/273304


Full Text

 Introduction



Clinically significant congenital mitral valve lesion is rare and is estimated to affect 0.4% of those with congenital heart disease.[1]

These often affect multiple segments of the mitral valve occurring in isolation or with other congenital heart disease, most of them being in the severe forms. However, frequently seen are the milder, atypical, isolated or incomplete forms of mitral defects and these are referred to as 'forme fruste of Shone anomaly.[2],[3],[4] Thus, through our case report, we would like to enlighten this rare entity called “parachute-like asymmetrical mitral valve.”

 Clinical Presentation



A 70-year-old hypertensive, diabetic male with a history of left frontoparietal infarct 3 years back presented with a sudden onset of right-sided weakness. He was diagnosed as left middle cerebral artery territory infarct on magnetic resonance imaging (MRI) [Figure 1]. He had an unremarkable cardiac history. He had a pulse rate of 68/min and a supine arm blood pressure of 130/80.{Figure 1}

Precordial examination showed normal heart sounds, with no murmur indicative of any valvular heart disease.

Twelve lead electrocardiogram taken with normal standardization showed sinus rhythm with rate of 73/min, with all the intervals and segments being within the acceptable limits. All other laboratory tests and chest X-ray were unremarkable. 24-h Holter monitoring recorded no abnormal rhythms.

The transthoracic echocardiography (echo) was done using Affiniti system (version 30, Philips Medical Systems, Andover, MA, USA) with a S4-2 phased array transducer, and the study was performed as per the recommendations from the American Society of Echocardiography 2019.[5]

Thus, starting with the parasternal view, it showed a dilated left atrium, with long thick chordae forming a net-like structure and attaching to a single papillary muscle on the inferolateral wall. Mitral valve had a restricted opening owing to this pathology [Figure 2].{Figure 2}

Parasternal short axis showed no regional wall abnormalities with good left ventricular (LV) systolic function. There were two heads of the papillary muscle, anterolateral papillary muscle being relatively short and rudimentary [Figure 3]. The mitral valve area was around 1.5 cm2 by planimetry method [Figure 4].{Figure 3}{Figure 4}

Apical four-chamber view had a pear-shaped mitral valve with a tunnel-like apex. Mitral valve opening was eccentrically oriented with single papillary muscle accepting all the chordal insertions. There was narrowing of interchordal space resulting in the secondary mitral orifice, leading to inflow obstruction [Figure 5]a and [Figure 5]b. Color Doppler interrogation at the mitral valve had an eccentric jet of mitral regurgitation of at least moderate degree which was also depicted by the continuous-wave Doppler across the mitral valve [Figure 6]a and b].{Figure 5}{Figure 6}

Mitral valve had a mean gradient of 5 mmHg and peak gradient of 13 mmHg [Figure 7].{Figure 7}

The apical three-chambered view also showed the origin of all the chordae from single papillary muscle [Figure 8].{Figure 8}

The LV cavity dimensions were within the normal limits (end-diastolic dimension 4.8 cm, end-systolic dimension 3.0 cm) with an LV ejection fraction of 62%. There was neither LV outflow tract obstruction nor any coarctation of the aorta. The interatrial and interventricular septum was intact. The aortic valve was trileaflet with no stenosis or regurgitation across the aortic valve. Evaluation of the right heart was normal.

The patient was discharged after improvement in his clinical status with a plan for regular follow-up. We also plan to do transesophageal echo on follow-up to check for any source of cardiac emboli, especially in the left atrium causing recurrent stroke in our patient.

 Discussion



Differentiating the entity

Parachute mitral valve is defined as all chords converging and getting inserted in one papillary muscle, commonly seen in the pediatric population.[6] It is usually seen as a part of Shone's anomaly (supravalvular mitral ring, parachute mitral valve, subaortic stenosis, and coarctation of the aorta).[7]

Parachute-like asymmetrical mitral valve is described as incomplete form of parachute mitral valve having two papillary muscle, one of them being hypoplastic and the other dominant papillary muscle, which receives all the chordal attachments leading to unifocalization of chorade.[8] It is divided into three types as described in [Table 1].{Table 1}

Embryogenesis

This condition is a persistent embryonic situation caused due to the disturbed lamination of the anterior and posterior parts of trabecular ridge between 5 and 19 weeks of gestation forcing them to condense into single papillary muscle and also resulting in the formation of accessory pathway of atrioventricular conduction.[4]

Clinical variants

Parachute-like asymmetrical mitral valve can occur in isolation or be associated with left-sided lesions (supravalvular mitral ring, mitral stenosis, subaortic stenosis, aortic stenosis, aortic atresia, supravalvular aortic stenosis, coarctation of the aorta, and aortic arch hypoplasia).

Thus, the adult patients with undiagnosed parachute-like asymmetrical mitral valve present with a wide range of spectrum starting from silent accidental detection to patients with heart failure (due to significant aortic/mitral regurgitation) or patients in atrial fibrillation or those who presented with sudden cardiac death. Rarely, it could be associated with aneurysm of basal muscular interventricular septum.[9]

It is seen that in the few patients who represent the grey zone where the lack of severe obstructive lesion in the left heart has allowed them to reach adulthood, supramitral ring is the main determinant of the clinical outcome.[10],[11]

Diagnosis and echocardiographic features

Currently, two-dimensional echo is the diagnostic imaging modality of choice. Echo findings show the presence of long thick chordae forming a net-like structure and getting attached to a single, dominant papillary muscle. Parasternal short axis shows the presence of two papillary muscle, one of them being dominant and the other one being rudimentary. Apical views show pear-shaped mitral valve configuration with eccentric opening associated with varying degrees of stenosis and regurgitation. Here, mitral stenosis is defined as mild when the mean gradient is between 3 and 5 mmHg and moderate to greater with a mean gradient of >5 mmHg value. These patients should also be screened for the other associated lesions as described above.

Follow-up strategy

After the initial assessment, the mitral lesions with no/minimal hemodynamic significance require no intervention to be done perse.[10]

However, such patients should be periodically assessed for the progressive worsening of the valvular lesions. Progressive mitral stenosis is defined as an increase in the mean gradient of at least 2 mmHg or by any increase from no mitral stenosis to the presence of stenosis, whereas progressive mitral regurgitation is described as an increase in the category of regurgitation relative to initial echo.[11]

Role of multimodality imaging

Currently, two-dimensional echo is the diagnostic method of choice, whereas transesophageal echo should be used as a tool in the more challenging case, especially to differentiate between true parachute mitral valve and parachute-like asymmetrical mitral valve and also to rule out the presence of left atrial/left atrial appendage thrombus.

MRI and multidetector computed tomography may be useful as a complementary imaging tool in patients with poor echo acoustic window.[12]

 Conclusion



The findings of this case have raised awareness of an incomplete, isolated form of rare congenital anomalies of parachute or parachute-like asymmetrical mitral valve in adults, the incidence of which might be far more frequent than expected. With the availability of better imaging techniques, such kind of rare anomalies is more likely to be recognized if the doctors, especially those involved in echo field, get acquainted with such a rare disease.

Acknowlegments

We would like to thank Dr. Ravindra Babu (Medical Superintendent, Apollo Hospital Jubilee Hills), Dr. Balaji Patel Kola (Interventional Radiologist) for the unconditionally support provided throughout the entire assignment, with a special mention of Mr. B Surinder for all the help and technical support.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Remenyi B, Gentles TL. Congenital mitral valve lesions: Correlation between morphology and imaging. Ann Pediatr Cardiol 2012;5:3-12.
2Celano V, Pieroni DR, Morera JA, Roland JM, Gingell RL. Two-dimensional echocardiographic examination of mitral valve abnormalities associated with coarctation of the aorta. Circulation 1984;69:924-32.
3Rosenquist GC. Congenital mitral valve disease associated with coarctation of the aorta: A spectrum that includes parachute deformity of the mitral valve. Circulation 1974;49:985-93.
4Oosthoek PW, Wenink AC, Wisse LJ, Gittenberger-de Groot AC. Development of the papillary muscles of the mitral valve: Morphogenetic background of parachute-like asymmetric mitral valves and other mitral valve anomalies. J Thorac Cardiovasc Surg 1998;116:36-46.
5Mitchell C, Rahko PS, Blauwet LA, Canaday B, Finstuen JA, Foster MC, et al. Guidelines for performing a comprehensive transthoracic echocardiographic examination in adults: Recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr 2019;32:1-64.
6Schiebler GL, Edwards JE, Burchell HB, Dushane JW, Ongley PA, Wood EH. Congenital corrected transposition of the great vessels: A study of 33 cases. Pediatrics 1961;27 (5) Suppl: 849-88.
7Shone JD, Sellers RD, Anderson RC, AdamsP Jr., Lillehei CW, Edwards JE, et al. The developmental complex of “parachute mitral valve,” supravalvular ring of left atrium, subaortic stenosis, and coarctation of aorta. Am J Cardiol 1963;11:714-25.
8Oosthoek PW, Wenink AC, Macedo AJ, Gittenberger-de Groot AC. The parachute-like asymmetric mitral valve and its two papillary muscles. J Thorac Cardiovasc Surg 1997;114:9-15.
9Mohan JC, Shukla M, Mohan V, Sethi A. Parachute mitral valve and Pacman deformity of the ventricular septum in a middle-aged male. Indian Heart J 2016;68 Suppl 2:S126-30.
10Hakim FA, Kendall CB, Alharthi M, Mancina JC, Tajik JA, Mookadam F, et al. Parachute mitral valve in adults-a systematic overview. Echocardiography 2010;27:581-6.
11Coles JG, Williams WG, Watanabe T, Duncan KF, Sherret H, Dasmahapatra HK, et al. Surgical experience with reparative techniques in patients with congenital mitral valvular anomalies. Circulation 1987;76:III117-22.
12Ucar O, Vural M, Cicekcioglu H, Pasaoglu L, Aydogdu S, Koparal S. Multidetector CT presentation of parachute like asymmetrical mitral valve. Br J Radiol 2008;81:266-28.