Chapter 16 / Heart Disease in the Child 259
Treatment includes stabilization of the patient with ventilatory and inotropic support
and correction of acidosis. Inhaled nitric oxide may be used to reduce pulmonary resis-
tance (80,81). A beneficial role of PGE
1
, which may relax the ductus venosus, has been
suggested (82). In severe cases, extracorporal membrane oxygenation (ECMO) may be
used as a lifesaving measure.
ANOMALOUS ORIGIN OF THE LEFT CORONARY ARTERY
In this rare, treatable lesion, the left coronary artery originates from the pulmonary
artery. As the pressure in the pulmonary artery decreases in the first weeks after birth,
perfusion pressure of the anomalous artery decreases. Low perfusion pressure and low
oxygen saturation may result in ischemia to the region supplied by the left coronary
artery. The whole coronary tree is usually supplied by the large right coronary artery
with retrograde flow in the left system via collateral arteries. Ischemia may cause left
ventricular dysfunction and mitral valve regurgitation. The presentation can be cardio-
genic shock in the infant or it may be more subtle, resulting in cardiomyopathy in older
age. Physical examination and chest X-ray do not differ from other forms of myocardi-
tis/cardiomyopathies. The electrocardiogram may reveal deep and wide Q-waves in the
left leads (I, avL, V4–6). The diagnosis may be made by echocardiography, where the
origin of the left coronary artery and the direction of flow through it can be established.
In uncertain cases, catheterization is indicated.
The patient may require preoperative inotropic support. Surgical treatment should
not be delayed, because without surgery, the mortality is high (83). A number of surgi-
cal techniques have been used. These include ligation of the left coronary artery, cre-
ation of an aorto-pulmonary window with a tunnel directing the blood flow from the
aorta to the left coronary artery [Takeuchi operation (84),], or reimplantation of the left
coronary artery to the aorta (85). Reported surgical results are much better for the
Takeuchi and reimplantation techniques (86).
EBSTEIN ANOMALY OF THE TRICUSPID VALVE
Ebstein anomaly of the tricuspid valve is a rare defect in which the septal and poste-
rior leaflets of the tricuspid valve are displaced downward toward the apex of the right
ventricle. The right ventricle is divided into an “atrialized” portion above the tricuspid
valve and a ventricular portion below the valve. The right atrial pressure is elevated as a
result of a combination of low right ventricular compliance, tricuspid regurgitation, and
systolic contraction of the atrialized right ventricle. An atrial septal defect or patent
foramen ovale is commonly present. Cyanosis results from the right-to-left shunt at the
atrial level. The clinical presentation may be hydrops fetalis (87), neonatal cyanosis
which may be severe and accompanied by cardiogenic shock, or mild cyanosis in the
older child. After birth, when the pulmonary vascular resistance is high, the right ventri-
cle may be incapable of propelling blood antegradely across the pulmonary valve in
severe cases, resulting in “functional” pulmonary atresia (88) and ductus-dependent
pulmonary circulation. Anatomical pulmonary stenosis or atresia may be present. On
physical examination, the baby is cyanotic and may be in shock. A systolic tricuspid
regurgitation murmur and a gallop may be heard. Chest X-ray may reveal extreme car-
diomegaly resulting from massive enlargement of the right atrium, with diminished pul-
monary vascularity. The ECG may reveal large P-waves, and a Wolff–Parkinson–White
pattern may be present. Echocardiography is diagnostic.
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