3 DISCUSSION
Ebstine anomaly is essentially a tricuspid valve disorder which begins
in the embryonic stage by failure of delamination 2,
5. Due to failure in delamination of inner layer of inlet part of right
ventricle in EA we see adherence of septal and posterior leaflets to the
underlying myocardium and as a consequence we saw downward displacement
of hinge points of septal and posterior leaflets from atrioventricular
junction 2, 5, 6. In contrast to septal and posterior
leaflets, anterior leaflet usually remains in the normal position due to
different embryonic origin of anterior leaflet versus posterior and
septal leaflets 4, 7. Septal (medial) and posterior
(inferior) leaflets originate from the tricuspid gully7 but the anterior leaflet developed from the lateral
endocardial cushion and lateral conus 2, so that,
anterior tricuspid leaflet is very rarely affected in EA and the attach
point of the septal and inferior leaflets never apically displaced
beyond the junction between ventricular inlet and apicotrabecular
component of RV 1, 7 and the junctional hing of the
anterior leaflet is very rarely affected 2, 7.
In our case which the symptoms represented in adulthood, a rare variant
of EA was seen with downward displacement of all three tricuspid
leaflets. Ebstein cases may represent at different ages due to severity
of structural and functional abnormality and also presence of associated
defects 8, such as our patient which well tolerated
till 35 years old and passed tow pregnancies with no complain of dyspnea
or right side failure symptoms. There was no same case in literature
with apical disposition of all three tricuspid leaflets. There was
reported few cases of isolated anterior leaflet displacement and not
septal and posterior ones, and displacement of septal or posterior
leaflets is the regular kind of EA, but apical downward of all three
ones was not reported till now.