Journal of The Indian Academy of Echocardiography & Cardiovascular Imaging

: 2022  |  Volume : 6  |  Issue : 1  |  Page : 66--68

Ebstein Anomaly of the Tricuspid Valve with Intact Inter-atrial Septum and Cor Triatriatum Dexter in an Asymptomatic Adult: The Tri-chambered Right Atrium

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

Correspondence Address:
Prof. Jagdish Chander Mohan
Institute of Heart and Vascular Diseases, Jaipur Golden Hospital, Sector 3, Rohini, New Delhi - 110 085


Ebstein anomaly of the tricuspid valve is characterized by apical displacement of septal and posterior leaflets of the tricuspid valve leading to the atrialization of right ventricular cavity and severe low-pressure tricuspid regurgitation. Cor triatriatum dexter is a rare congenital cardiac anomaly in which a membranous structure divides the right atrium into two chambers. This combination is rare and very few cases have been described in the literature. We herein report an asymptomatic young female who was incidentally detected to have these anomalies with intact atrial septum. Echocardiographic examination showed tri-chambered right atrium consisting of atrialized right ventricle, anterior right atrial chamber, and the posterior right atrial sinus portion.

How to cite this article:
Shukla M, Mohan JC. Ebstein Anomaly of the Tricuspid Valve with Intact Inter-atrial Septum and Cor Triatriatum Dexter in an Asymptomatic Adult: The Tri-chambered Right Atrium.J Indian Acad Echocardiogr Cardiovasc Imaging 2022;6:66-68

How to cite this URL:
Shukla M, Mohan JC. Ebstein Anomaly of the Tricuspid Valve with Intact Inter-atrial Septum and Cor Triatriatum Dexter in an Asymptomatic Adult: The Tri-chambered Right Atrium. J Indian Acad Echocardiogr Cardiovasc Imaging [serial online] 2022 [cited 2022 Jul 6 ];6:66-68
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Full Text


Ebstein anomaly is a rare congenital cardiac defect characterized by apical displacement of the septal and posterior leaflets along with large fenestrated anterior leaflet of the tricuspid valve due to the arrested process of delamination. It is frequently associated with right heart anomalies, and atrial septal defect is present in 80%–94% cases.[1] There is functional impairment of the right ventricle due to systolic ballooning of the atrialized portion, tricuspid regurgitation, and dilatataion of the annulus. Cor triatriatum dexter is an unusual cardiac abnormality with division between the sinus and primitive trabeculated portions of the right atrium caused by persistence of the right valve of the embryonic sinus venosus as a membrane of variable thickness.[2] Posterior smooth chamber receives blood from venae cavae and coronary sinus and communicates with anterior trabeculated chamber having right atrial appendage and the tricuspid valve. The extent of obstruction by the membrane dictates symptoms, but in the presence of this combination, it may not be possible to document trans-membrane pressure gradients by Doppler. Occasionally, cor triatriatum dexter can mimic Ebstein anomaly.[3] We herein report a 24-year young female who on routine examination for unrelated abdominal pain was detected to have Ebstein anomaly of the tricuspid valve, intact interatrial septum, cor triatriatum dexter. The two-dimensional (2D) and three-dimensional (3D) echocardiographic appearance of tri-chambered right atrium are striking.

 Case Report

This 24-year-old girl was first examined 5 years back for vague abdominal pain and detected to have scratchy precordial systolic murmur. A diagnosis of the Ebstein anomaly was made. She remained asymptomatic during this 5-year period, got married, and gave birth to a healthy baby boy when she was 22-years of age. She reported for a routine examination on June 1, 2021, and had no symptoms. Physical examination revealed a medium-built dusky young girl with a height of 164 cm, weight 54 kg, blood pressure 110/70 mmHg, pulse rate 74/min, peripheral oxygen saturation of 98% at rest, and 96% after 6-min walk test. Jugular venous pressure was not elevated and there was no pedal edema. Precordial examination showed diffuse apical impulse, visible precordial pulsations, normal first heart sound, and wide split variable second heart sound with reduced pulmonary component. A short grade 2/6 systolic murmur was heard all over precordium. No additional sounds were audible. A 12-lead electrocardiogram showed sinus rhythm, tall broad P waves (4 mm × 120 ms), mean front QRS axis of 100°, and complete right bundle branch block. Chest skiagram showed enlarged globular silhouette with normal pulmonary vasculature. Routine biochemistry was normal.

2D-echocardiographic examination showed mildly dilated inferior vena cava (18 mm) with <50% respiratory variation, holosystolic flow reversal in hepatic veins with no flow reversal during atrial contraction, large sail-like anterior tricuspid valve leaflet with free margin attachment to moderator band through short chords, curled-up doughnut like mass at the place of septal leaflet attached to ventricular septum 2 cm caudal to the annulus and restricted posterior leaflet attached one cm caudal to the origin of anterior tricuspid leaflet. Tricuspid annulus was 54 mm in diameter [Figure 1]. Severe low pressure (peak velocity 1.8 m/s) tricuspid regurgitation caused ballooning of the atrialized chamber during systole. The right atrium was partitioned into two chambers (anterior and posterior) by a membrane [Figure 2] and [Figure 3]. The membrane originated in the interatrial septum, contiguous with the mouth of the coronary sinus and ran along the lateral side of the right atrium, leaving a 9-mm defect (with accelerated color Doppler flow at that level with pan-diastolic flow velocity of 90 cm/s [Figure 4] and [Figure 5], although without significantly obstructing the flow) and forming an entry chamber into which the venae cavae opened and another chamber from the membrane to the tricuspid valve. Interatrial septum was intact. The pulmonary veins, left atrium and the left ventricle were normal. There was moderate pulmonary valve regurgitation with early diastolic velocity of 1.5 m/s and normal mitral and aortic valves. The patient is being followed conservatively.{Figure 1}{Figure 2}{Figure 3}{Figure 4}{Figure 5}


The tricuspid valve leaflets and chordae tendineae develop by undermining of the inner layers of the right ventricular inlet (delamination). In Ebstein anomaly, the delamination process is incomplete, resulting in the abnormal apical insertion of the septal and posterior tricuspid valve leaflets at the junction of the inlet and trabecular portions of the right ventricle.[1] The anterior leaflet is formed much earlier in embryological development and may escape this fault. It may contain various amounts of muscle and can even consist of a complete muscular diaphragm between the inlet and apical portions of the right ventricle. Anterior tricuspid leaflet morphology, its mobility, and attachment form the basis of classification of the Ebstein anomaly.

During embryonic development, the common atrium is separated from the sinus venosus by a valve with two leaflets (the venous sinus valve). Subsequently, the left leaflet of the venous sinus valve is incorporated into the interatrial septum and forms part of the septum secundum. The right leaflet is reabsorbed around the 12th week of gestation, leaving 2 structures: the Eustachian valve at the junction of the inferior vena cava and the coronary valve at the mouth of the coronary sinus.[2] The persistence of the right leaflet of the venous sinus valve may manifest as prominent Eustachian valve, the Chiari network, or cor triatriatum dexter. Embryologically, the process of delamination of the tricuspid valve leaflets and absorption of the right valve of the sinus venosus occur at the same time and hence simultaneous fault in both phenomena and the combination of anomalies seen in this case is fortuitously possible.[3]

Extensive literature search has shown only three previously reported cases of Ebstein anomaly with cor triatriatum dexter.[4],[5],[6] All these three cases had atrial septal defect. Our patient is unique in having intact atrial septum in the presence of this combination. Anatomic variants of the remnants of the right valve of the sinus venosus in adults are common and frequently observed on cardiac imaging studies. These include a prominent Eustachian valve, the Chiari network, and cor triatriatum dexter. True cor triatriatum dexter should only be considered if there is a complete flow-obstructing membrane (with a hole) partitioning the right atrium into trabeculated and sinus portions with a definite septal attachment. Our case fulfills these criteria as shown in 2D and 3D echocardiographic views, except that Doppler gradients across the membrane were not high. Among other associated anomalies are stenosis or atresia of the pulmonary valve, tricuspid valve abnormalities, and atrial septal defect.[2] In our case, pulmonary valve was normal and atrial septum did not show any deficiency. A large Italian study has described a benign variant of cor triatriatum dexter seen in about 1.5% of children that is characterized by no flow obstruction and no other associated congenital anomaly.[7] It is possible that the case reported herein may fall in this category as far as description of cor triatriatum is concerned and the association between the two rare anomalies could be fortuitous.


Ebstein anomaly of the tricuspid valve can coexist with cor triatriatum dexter and intact atrial septum.

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 initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

J C Mohan is an editorial board member of the Journal of The Indian Academy of Echocardiography & Cardiovascular Imaging. The article was subject to the journal's standard procedures, with peer review handled independently of this editor and their research groups.

There are no other conflicts of interest.


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