Mitral Annulus Disjunction, Annuloaortic Ectasia, and Pseudoaneurysm of Aortomitral Interannular Fibrosa in a 2-Year-Old Child

Madhu Shukla; Jagdish Chander Mohan

doi:10.4103/jiae.jiae_60_22

INTERESTING CASE REPORT

Year : 2023 | Volume : 7 | Issue : 1 | Page : 44-46

Mitral Annulus Disjunction, Annuloaortic Ectasia, and Pseudoaneurysm of Aortomitral Interannular Fibrosa in a 2-Year-Old Child

Madhu Shukla, Jagdish Chander Mohan
Department of Cardiology, Institute of Heart and Vascular Diseases, Jaipur Golden Hospital, New Delhi, India

Date of Submission	30-Nov-2022
Date of Acceptance	20-Dec-2022
Date of Web Publication	10-Feb-2023

Correspondence Address:
Prof. Jagdish Chander Mohan
A51, Hauz Khas, New Delhi - 110 016
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jiae.jiae_60_22

Abstract

Genetically determined deficiency of connective tissue predisposes to the prolapsed mitral valve and an abnormal fibrous annulus including mitral annulus disjunction and dehiscence of aortomitral annular fibrosa. In a more severe phenotype, there may be abnormal aortic tissue, leading to annuloaortic ectasia. This report describes a 2-year-old male child who presented with failure to thrive and was found to have Barlow's syndrome with bileaflet mitral valve prolapse and mitral annulus disjunction, annuloaortic ectasia, and a pseudoaneurysm of interannular fibrosa. The case is reported for its interesting unifying linkage among various defects.

Keywords: Annuloaortic ectasia, interannular pseudoaneurysm, mitral annulus disjunction, myxomatous aortic valve

How to cite this article:
Shukla M, Mohan JC. Mitral Annulus Disjunction, Annuloaortic Ectasia, and Pseudoaneurysm of Aortomitral Interannular Fibrosa in a 2-Year-Old Child. J Indian Acad Echocardiogr Cardiovasc Imaging 2023;7:44-6

How to cite this URL:
Shukla M, Mohan JC. Mitral Annulus Disjunction, Annuloaortic Ectasia, and Pseudoaneurysm of Aortomitral Interannular Fibrosa in a 2-Year-Old Child. J Indian Acad Echocardiogr Cardiovasc Imaging [serial online] 2023 [cited 2023 Oct 3];7:44-6. Available from: https://jiaecho.org/text.asp?2023/7/1/44/369551

Introduction

The presence of mitral annulus disjunction (MAD) is common in patients with mitral valve prolapse (MVP) in younger patients, and is independently associated with severe myxomatous disease involving bileaflet MVP and marked leaflet redundancy.^[1] MAD in patients with MVP has received renewed attention in view of its malignant nature resulting in ventricular arrhythmias and an increased risk of sudden cardiac death.^[2] MAD may induce mechanical stress on the basal inferolateral myocardial wall and papillary muscles through the abnormal systolic curling motion of the subvalvular region of the left ventricular (LV) free wall, eventually leading to myocardial fibrosis providing a proarrhythmogenic substrate.^[3] More recently, its association with connective tissue disorders such as Marfan's syndrome and Loeys–Dietz syndrome has been reported.^[4],[5],[6]

We herein report a 2-year-old male child who presented with several congenital anomalies secondary to altered connective tissue architecture of the heart.

Case Report

This 2-year-old male child (weight 11 kg, height 90 cm, and body surface area 0.536 m²) was brought to the hospital with a complaint of failure to thrive. There were no skeletal deformities. Developmental milestones were normal. The child was comfortable with a resting heart rate of 118 beats/min, supine left arm blood pressure of 70/40 mmHg, and hyperkinetic precordium with no murmurs or extra sounds. The chest skiagram showed an enlarged cardiac silhouette. The 12-lead electrocardiogram revealed sinus rhythm, right axis deviation, and prominent R waves in all precordial leads [Figure 1].

Figure 1: A 12-lead electrocardiogram of the child showing sinus rhythm, right axis deviation, and prominent R waves in leads V1-V2

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The patient underwent a transthoracic echocardiographic examination (GE Vivid system E9; GE Healthcare). Image acquisitions and standard measurements were carried out in accordance with the guidelines. Data on aortic diameters, valvular function, cardiac dimensions, and cardiac function were collected. Mitral valve leaflets were thickened, hypermobile, and with elongated chords. Bileaflet MVP was present and defined as a mitral leaflet or scallop displacement of 2 mm or more beyond the mitral annulus toward the left atrium (LA) in systole [Figure 2] and [Video 1]. The maximum diastolic thickness of the leaflets was 6 mm with fundamental imaging. The anteroposterior mitral annular diameter measured during end systole (25 mm, Z score = +2.54) and end diastole (24 mm, Z score = +2.3) were increased in the parasternal long-axis view. The MAD distance measured during end systole in parasternal long-axis views from the left atrial wall mitral valve leaflet junction to the base of the LV inferolateral wall was 11 mm. MAD measured in apical five-chamber view was 12 mm [Figure 3] and [Video 2].

Figure 2: Parasternal short-axis view (a) and parasternal long-axis view (b) showing thickened and redundant leaflets with bileaflet mitral valve prolapse (arrows)

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Figure 3: Transthoracic echocardiographic apical five-chamber view (a) and parasternal long-axis view (b) showing mitral annulus disjunction distance of 11 mm in end systole. Furthermore, note bileaflet mitral valve prolapse in panel b. LV: Left ventricle, AO: Aorta, LA: Left atrium

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[Additional file 1]

Video 1: Transthoracic parasternal long axis view showing bileaflet mitral valve prolapse, systolic MAD, and enlarged

mitral and aortic annuli

[Additional file 2]

Video 2: Modified long-axis view showing dilated aortic root and aortic annulus and pseudoaneurysm

The aortic diameter at the level of the sinus of the Valsalva in diastole using the leading edge-to-leading edge convention was 31 mm (Z = 10.17, normal range: 11.47–17.78 mm, Boston), whereas the aortic annulus measured in mid-systole was 21 mm (Z score = 9.44, normal range: 9.2–13.25 mm, Boston). Diameters of the tubular ascending aorta (20 mm, normal range 12–16 mm, Z score = 3.95) and the arch (13 mm) were also measured. Aortic and mitral regurgitation graded by color Doppler imaging were mild [vena contract 2 mm, [Figure 4]]. An expansile space was observed between aortic and mitral annuli (2 cm × 1.4 cm) communicating with the LV outflow tract through a 4 mm wide neck. It expanded in systole and collapsed in diastole and showed to-and-fro flow [Figure 5] and [Figure 6]. Tissue from this pseudoaneurysm extended along the LA reflection of the aortic root toward and along the atrial septum. Its wall was 4 mm thick, possibly due to myxomatous change. It had no communication with the aortic root or the LA. Visually, ventricular functions were normal. Holter monitoring for ventricular arrhythmias was not performed. The child's father did not agree to genetic testing.

Figure 4: Parasternal long-axis view with (a) and without color (b) showing dilated aortic root and annulus and jet of aortic regurgitation

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Figure 5: Transthoracic echocardiographic short-axis view (a) and modified parasternal long-axis view (b) showing dilated aortic root with sinuses and a pseudoaneurysm of mitral-aortic annular fibrosa (arrow). LV: Left ventricle, AO: Aorta, LA: Left atrium

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Figure 6: Modified long-axis view (a) and 4-chamber view (b) showing pseudoaneurysm of interannular fibrosa (arrow). LV: Left ventricle, AO: Aorta, LA: Left atrium, RV: Right ventricle

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The patient is on conservative follow-up.

Discussion

This 2-year-old child with Marfan-like cardiovascular phenotype (with no skeletal or ocular features and no genetic testing) revealed a myxomatous MVP, significant MAD, dilatation of aortic annulus, and aortic root and dehiscence of aortomitral annular fibrosa resulting in a pseudoaneurysm. In the population-based Copenhagen Baby study, MVP and Barlow's syndrome were reported in 0.35% and 0.13% of babies, respectively.^[7] However, there was no mention of MAD in this population. Association of MVP with aortic root and sinuses dilatation has been reported in Marfan syndrome and its alike^[4] Demolder et al. reported a 34% prevalence of MAD in Marfan syndrome, wherein 32% of patients were <10 years of age.^[5] MAD was more often seen in pediatric patients than in adults. MAD was associated with MVP and larger aortic roots and ventricular arrhythmias. In this study, serious aortic events occurred more frequently only in those with a MAD distance of >10 mm. The MAD distance was not related to age or body surface area and did not increase over time. Another study reported increased mitral and aortic events in those with MAD.^[6] MAD may occur without MVP and is still associated with ventricular arrhythmias.^[8]

Dehiscence of mitral-aortic intervalvular fibrosa resulting in a pseudoaneurysm is a rare anomaly secondary to infective endocarditis and surgical or nonsurgical trauma.^[9] Very few cases of congenital origin have been described.^[9] Although intuitively possible, it has not been reported in patients with Marfan-like cardiovascular phenotype. Another interesting feature of this pseudoaneurysm was its thick wall possibly due to the excessive myxomatous tissue. Whether such a change protects it from rupture or produces compressive change is not known.

Conclusion

In conclusion, we present an unusual case of a 2-year-old child with multiple anomalies involving a cardiovascular fibrous skeleton and Marfan-like cardiovascular phenotype.

Contribution of authors

Both authors contributed equally in acquiring images, review of the literature, and writing the manuscript.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given their consent for the child's images and other clinical information to be reported in the journal. The guardian understands that child's name 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.

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