Keywords: Mitral valve, Echocardiography, Three-dimensional
echocardiography, Congenital heart defects, Atrial septal defect
Data availability: The data that support the findings of this
study are available on request from the corresponding author. The data
are not publicly available due to privacy or ethical restrictions.
Abstract
A 60-year-old female was referred to our clinic for evaluation of her
rapidly progressive dyspnea, she had no previuos history of heart
disease. A murmur was noted on her examination and transthoracic
echocardiography was so difficult to be performed due to poor acoustic
windows so she was referred to do a transesophageal echocardiography
that showed an ostium primum atrial septal defect (ASD) with left to
right shunt and a quadrileaflet mitral valve with severe regurgitation.
Later on, she underwent surgery with Ostium Primum ASD closure by a
patch and double cleft repair by suture after right heart
catheterization.
Introduction:
Partial atrioventricular canal (PAVC) defect is a form of endocardial
cushion defect that is infrequently seen in adults with very rare case
reports published. Although the results of surgery in younger
individuals is well known and studied, yet there is a very rare data
about results of surgery in older patients.
Case Report:
A 60-year-old female patient was referred to our clinic for evaluation
of her rapidly progressive dyspnea that started few days before her
presentation. She had no previuos history of cardiovascular disease, nor
other risk factors. On clinical examination, a systolic murmur was heard
over the apex. A transthoracic echocardiography was difficult due to
poor acoustic windows but there was marked dilatation of the right
cardiac chambers so the patient was scheduled for a transesophageal
echocardiography (TEE) that revealed an atrial septal defect (ASD) type
ostium primum with left-to-right shunt, right chambers dilatation and
mitral regurgitation (Video 1, 2). 3-dimensional (3D) transesophageal
echocardiography was performed with Philips X7-2t probe and allowed us a
correct 3D measurement of the defect size (2.1 x 2.3 cm) using Qlab10
software for post-processing imaging (Figure 1), the evaluation of a
quadrileaflet mitral anatomy (Video 3, Figure 2) with a cleft in the
anterior mitral leaflet (Video 4, figure 3) and another cleft in the
posterior mitral leaflet (Video 5, figure 4). The valve appeared to be
divided into four scallops A1-A2 P1-P2 as we can see from surgical view
of mitral valve (Video 6).
Later on, the patient underwent surgical closure of Ostium Primum ASD by
a patch and double cleft repair by suture after right heart
catheterization.
Six months after the procedure, the patient reported significant
improvement in her functional status and her shortness of breath
improved considerably. TTE performed 6 months after the surgery
documented a significant reduction in the right chambers dimensions.
Discussion
Partial atrioventricular canal (PAVC) defect is a form of endocardial
cushion defect infrequently encountered in adults; few reported patients
have survived into the sixth or seventh decade of
life.1-3 PAVC defect was defined as an ostium primum
atrial septal defect but with two separate atrioventricular valve rings,
a cleft in the anterior mitral leaflet and no appreciable
interventricular communication. Failure of fusion of the leaflets
derived from the superior and inferior cushions can result in clefting
of the aortic leaflet subsequent to otherwise normal development; it is
the latter arrangement that results in the trifoliate left component of
the common valve found in the setting of AVSDs.4Trileaflet mitral valves have only been recently reported in the
literature as an extremely rare distinct disease entity.5,6 There are 6 published reports of 7 patients with
trileaflet mitral valves, all of which were diagnosed by 3D
echocardiography.7
We report an even more rare case where the clefts affect both the
anterior mitral leaflet and the posterior mitral leaflet in a patient
with ostium primum atrial septal defect turning the valve into a
quadrileaflet valve.
Conclusion
The present clinical case highlights the importance of 3D TEE as the
only tool for an accurate knowledge of the mitral valve anatomy and
helping the surgeon in choosing the best mitral repair technique. In
this specific case, the evidence of mitral regurgitation at the level of
the clefts changed our decision towards the suturing of the same valve
material and avoiding the use of annuloplasty.
References
1. Wiener L, Schneider PJ, Cox JW: Persistent cardiac ostium primum: a
diagnostic dilemma in the aged. J Am Geriatr Soc 14:1156, 1966
2. Campbell M, Neill C, Suzman S: The prognosis of atrial septal defect.
Br Med J 1: 1375, 1957
3. Heath D: Long survival in partial persistent common atrioventricular
canal. Br J Dis Chest 62: 207, 1968
4. Kanani M, Moorman AFM, Cook AC,Webb S, Brown NA, Lamers WH, Anderson
RH. Development of the atrioventricular valves: clinicomorphological
correlations. Ann Thorac Surg 2005;79:1797–1804
5. D’Ancona G, Neuhausen-Abramkina A, Atmowihardjo I, Kische S, Ince H.
Tri-leaflet mitral valve anatomy: a rare occurrence leading to severe
mitral valve regurgitation. Eur Heart J 2015;36:1697.
6. Moya-Mur J-L, García-Martín A, Jiménez-Nacher JJ, Fernández- Golfín
C, Zamorano-Gómez J-L. “Tri-leaflet mitral valve morphology”: a new
phenotypic expression in hypertrophic cardiomyopathy? Eur Heart J
Cardiovasc Imaging 2015;16:692.
7. Jason Chui, MBChBa, Robert H. Anderson, MDb, Roberto M. Lang, MDc,
and Wendy Tsang, MDd. The trileaflet mitral valve. Am J Cardiol
2018;121:513–519
Figure/Video Legends
Video 1 ME 0° four-chambers
view showing an ostium primum ASD and right chambers dilatation. ME
=midesophageal; ASD= Atrial septal defect
Video 2 ME 0° four-chambers view showing left-to-right shunt and
mitral regurgitation. ME = midesophageal
Video 3 3D TEE surgeon “en face” view showing clefts in the
anterior and posterior mitral leaflets dividing the valve into four
scallops. TEE= Transesopgaheal Echocardiography
Video 4 3D TEE view from LAA perspective focused on ostium primum
ASD and AML cleft. LAA =Left atrial appendage; ASD = atrial septal
defect; AML = Anterior mitral leaflet.
Video 5 3D TEE cropped on the posterior mitral leaflet showing
cleft between P1-P2.
Video 6 3D TEE “en face” view of quadrileaflet mitral valve.
Figure 1 MPR of defect showing an ostium primum ASD with
diameters 2.1 x 2.3 cm. MPR= MultiPlanarReconstruction; ASD = Atrial
septal defect
Figure 2 “En face” view of the mitral valve from the left
atrium. AV= Aortic valve; TV =tricuspid valve; LAA= left atrial
appendage; ALC= anterolateral commissure; PMC= posteromedial commissure
Figure 3 Focused 3D image on the OP ASD and AML cleft. AO= aorta;
OP ASD = ostium primum atrial septal defect; AML = Anterior mitral
leaflet
Figure 4 3D shows another detail, a bilobate P2 scallop with an
indentation between medial and lateral lobe (asterisks). From this view
we can appreciate the main difference between cleft and indentation:
cleft is deeper than indentation and reaches the posterior annulus.