ultrasound diagnosis of fatal anomalies

DOUBLE-OUTLET RIGHT VENTRICLE
In a complete AV block, the atria and ventricles
beat regularly but are completely dissociated
from one another. In sinus bradycardia, 1 : 1 conduction
takes place from the atria to the ventricles.
In case of atrial bigeminal rhythm, certain
isolated beats are transferred to the ventricles
and others are not. In second-degree AV block, 3:
1 or 2 : 1 conduction to the ventricles is possible.
80–100 bpm is found in sinus bradycardia; this
may be sufficient for normal development of the
child. The prognosis is poor if a complete AV
block resulting from a complex malformation is
diagnosed, or if the frequency is below 55 bpm.
The fetus is not affected hemodynamically if
there is a second-degree AV block.
Clinical management: Further sonographic
screening, anti-Rho, anti-La and antiphospholipid
antibodies should be determined either
to confirm or to exclude autoimmune disease. If
there is structural malformation, karyotyping is
advised. After 32 completed weeks, premature
delivery is an option if cardiac insufficiency and
hydrops develop. At earlier gestation, maternal
therapy with steroids or plasmapheresis may be
successfully administered. There is no consensus
regarding the mode of delivery. “Fetal distress” is
difficult to diagnose using cardiotocography
during labor, and repeated fetal blood analysis is
only valuable for a short period. Pulse oximetry
may help in this situation. Cesarean section
should be considered if hydrops develops and if
the prognosis is not hopeless due to other cardiac
anomalies.
Procedure after birth: Intensive cardiac care is
needed in the neonatal stage. If there is a bigeminal
pulse and sinus bradycardia, therapy is usually
not needed. In the presence of a complete AV
block with a bradycardia of under 55 bpm or
generalized hydrops, pacemaker installation
should be considered.
Prognosis: This depends on the cause of the
bradycardia. Cases of bigeminal pulse have a
good prognosis and the condition may disappear
spontaneously. However, in 1% of cases, tachyarrhythmia
may develop. A heart frequency of
Double-Outlet Right Ventricle (DORV)
Definition: This is a complex cardiac anomaly in
which both great vessels arise from the right
ventricle. The left ventricle is emptied through a
VSD to the right ventricle.
Incidence: Rare; 1.5–2% of congenital heart disease.
Sex ratio: M:F=1:1.
References
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Clinical history/genetics: Sporadic occurrence.
With one affected sibling, the rate of recurrence
is 3–4%. Chromosomal aberration is found in
10–15% of cases.
Teratogens: Not known.
Associated malformations: Tracheo-esophageal
fistula.
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