CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 9/10, October/November 2013
AFRICA
383
Chromosomal analysis confirmed Down’s syndrome (47, XX,
+21). Elevated C-reactive protein suggested possible neonatal
sepsis that was later confirmed on blood culture, as this
was positive for
Acinetobacter baumannii
species, which was
sensitive to Carbapenems. Sepsis was successfully treated with
Meropenem following unsuccessful empirical antibiotic therapy.
Heart failure therapy (digoxin, furosemide) and potassium
supplements were added.
C-reactive protein levels later normalised, she was weaned off
oxygen and the heart failure treatment was stopped on follow up
at the age of six months. She was thriving well off anti-failure
medication with just mild tricuspid regurgitation at the last
follow up at three years of age.
Case 2
A 38-year-old female, gravida 11, para 4, presented at the
prenatal diagnosis unit 17 + 3 weeks pregnant. She had two
live babies but had also suffered two ectopic pregnancies, two
spontaneous miscarriages, two pregnancy terminations before 16
weeks’ gestation and two intrauterine deaths. An amniocentesis
revealed a male foetus with Down’s syndrome (47, XY, +21). In
view of her poor obstetric history and strong wish for another
child, the couple decided to continue with the pregnancy.
A foetal echocardiogram performed at 32 weeks’ gestation
showed situs solitus, levocardiawith atrioventricular concordance,
and normal pulmonary and systemic venous return. The right
atrium was dilated and the right ventricle was smaller than the
left ventricle due to a very apically displaced coaption point of
an abnormal tricuspid valve, consistent with Ebstein’s anomaly.
There was severe tricuspid regurgitation with a velocity of 3.4
m/s, giving an estimated right ventricular pressure of 46 mmHg
+ right atrial pressure.
A male infant was born by normal vaginal delivery at
gestational age of 36 + 6 weeks. His birth weight was 2 840
g and Apgar scores were recorded as 8 at one minute and 9 at
five minutes. The baby was cyanotic on room air with oxygen
saturations of 60% that went up to 75% with the administration
of 100% oxygen.
Further examination revealed features of Down’s syndrome
and severe respiratory distress. There were scattered pulmonary
rhonchi and a 4/6 holosystolic murmur was heard in the 4th
intercostal space, left parasternal border. The chest X-ray showed
a ‘wall-to-wall’ heart such that it was not possible to comment on
pulmonary vascularity (Fig. 2).
The ECG revealed sinus rhythm with a rate of 126 bpm, QRS
axis of +120, P axis of +45, PR interval of 120 ms, P pulmonale,
incomplete right bundle branch block and QTc of 455 ms (Fig.
3). The echocardiogram showed severe Ebstein’s anomaly with
functional pulmonary atresia, large right-to-left shunting at the
atrial level and ductal-dependent pulmonary circulation. In light
of the baby’s poor prognosis it was decided after consultation
with the parents to withdraw further active management and the
baby died 38 hours after birth.
Discussion
We present two cases of Ebstein’s anomaly in babies with Down’s
syndrome, which illustrate a less severe and an extreme form of
this cardiac defect, respectively. Ebstein’s anomaly is defined as
more than 0.8 cm/m
2
apical displacement of the septal leaflet
of the tricuspid valve.
7
This may be associated with adherence
of both the septal and posterior leaflets of the tricuspid valve
to the myocardium, downward displacement of the functional
annulus, dilatation of the ‘atrialised’ right ventricle, redundancy,
fenestrations, tethering of the anterior leaflet, and dilatation of
the true tricuspid valve annulus.
8
In Ebstein’s anomaly, there is a failure of delamination of the
inner layers of the inlet zone of the ventricles, the mechanism of
which is not well understood.
9
The clinical presentation varies
Fig. 2. Roentgenogram of case 2 showing a ‘wall-to-wall’
heart due to right atrial dilatation.
Fig. 3. ECG of case 2 showing the P pulmonale of right atrial enlargement and incomplete right bundle branch block,
often seen in Ebstein’s anomaly.
