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 Case
Report
Ebstein
syndrome
by
Heidi E. Karpen, MD
Assistant Professor of Pediatrics
This
3023 gm infant was born at 38 weeks’ gestation by repeat
cesarean section to a 22-year-old gravida III para II mother.
Initially, the baby was admitted to the newborn nursery but was
noted to be cyanotic at six hours of life. Physical exam revealed
an infant in moderate respiratory distress with a 3/6 holosystolic
murmur loudest at the RSB and a room air pulse oximetry of 69%.
Arterial blood gas (ABG) on 100% oxyhood showed pH 7.34 pCO2 41
pO2 27. Chest roentgenogram (CXR) revealed a cardiac silhouette
that occupied >90% of the thoracic cavity. Patient was intubated
and prostaglandin (PGE1) was started. Follow-up ABG on endotracheal
CPAP and 100% oxygen was similar to that in room air.
On
the second day of life (DOL), an echocardiogram revealed apical
displacement of the septal leaflet of the tricuspid valve, which
was severely limited by tethering to the interventricular septum.
The anterior leaflet also was tethered but less so. These anomalies
resulted in significant tricuspid regurgitation, producing severe
right atrial dilation. The pulmonary valve was hypoplastic with
minimal antegrade flow and trivial regurgitation. A large patent
ductus arteriosus (PDA) was noted with left-to-right shunting.
The right ventricle was small with severe hypertrophy but with
qualitatively good ventricular systolic function.
On
DOL 4, cardiac catheterization confirmed the echocardiographic
findings with a pulmonary balloon valvuloplasty. Over the next
several weeks, the infant was weaned from support and was discharged
on oral furosemide. Discharge CXR showed marked reduction in the
size of the cardiac silhouette.
Discussion
Ebstein
anomaly is a congenital cardiac defect consisting of three main
components—severe malformation of the tricuspid valve, atrialization
of the right ventricular wall, and patent foramen ovale. Ebstein
anomaly may occur as an isolated defect or in conjunction with
coarctation of the aorta or L-transposition of the great arteries.
Wolff-Parkinson-White syndrome, or concealed bypass tracts, is
seen in about 20% of patients.
Neonates
with severe Ebstein anomaly typically present with cyanosis and
signs of right heart failure. The murmur usually is a low-frequency
holosystolic murmur of tricuspid regurgitation. ECG typically
shows right bundle branch block with or without right atrial enlargement.
Chest radiograph shows marked cardiomegally due to right atrial
enlargement. The extent of cardiac enlargement is a useful tool
in predicting severity and outcome. In mild forms, the diagnosis
may be suspected during evaluation of a click or SVT.
The
factors most strongly associated with poor outcome are diagnosis
in the fetal or neonatal period, echocardiographic evidence of
right ventricular outflow tract obstruction, and cardiothoracic
ratio on CXR >90%.
Mild
forms of Ebstein anomaly do not require any specific therapy and
generally do well. Severely affected infants may have little prograde
pulmonary flow and hence are ductal dependent. For these patients,
therapy may require prolonged prostaglandin therapy or ECMO with
subsequent surgical intervention. Treatment with iNO and balloon
valvuloplasty offers a minimally invasive alternative and may
delay the need for more aggressive intervention.
References
1.
van Son JA, Konstantinov IE, Zimmermann V. Wilhelm Ebstein and
Ebstein’s malformation. Eur J Cardiothorac Surg 2001 Nov;20(5):1082-1085.
2.
Celermajer DS, Bull C, Till JA, Cullen S, et al. Ebstein’s anomaly:
presentation and outcome from fetus to adult. J Am Coll Cardiol 1994 Jan;23(1):170-176.
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