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The correct answer is C. Tetralogy of Fallot is
the most common cause of cyanosis within the
fi rst few weeks of life. The skin becomes bluish
because of the malformed right-to-left shunt.
Infants also have worsening cyanosis with agitation,
diffi culty feeding, and failure to gain
weight. Patients may also have clubbing of the
fi ngers and toes or even polycythemia. The
four components of the teratology are (1) ventricular
septal defect, (2) overriding aorta, (3)
infundibular pulmonary stenosis, and (4) right
ventricular hypertrophy.
Answer A is incorrect. Atrial septal defects typically
are not clinically apparent until adulthood,
when a patient experiences Eisenmenger’s
syndrome, a reversal of blood fl ow
caused by pulmonary hypertension.
Answer B is incorrect. Patent ductus arteriosus
typically is not clinically apparent until adulthood,
when a patient experiences Eisenmenger’s
syndrome, a reversal of blood fl ow
caused by pulmonary hypertension.
Answer D is incorrect. Transposition of the
great vessels is a condition that leads to early
cyanosis, but it is not as common as tetralogy
of Fallot.
Answer E is incorrect. Ventricular septal defects
(VSDs) are the most common cardiac
congenital defects, but they do not present
with early cyanosis. Infants with larger VSDs
present with tachypnea, dyspnea, and feeding
diffi culties. In addition, they have other signs
of breathing diffi culties such as subcostal or
intercostals retractions and a hyperdynamic
precordium (brisk, quick movement of the thorax).
A holosystolic murmur may be heard on
auscultation.
the most common cause of cyanosis within the
fi rst few weeks of life. The skin becomes bluish
because of the malformed right-to-left shunt.
Infants also have worsening cyanosis with agitation,
diffi culty feeding, and failure to gain
weight. Patients may also have clubbing of the
fi ngers and toes or even polycythemia. The
four components of the teratology are (1) ventricular
septal defect, (2) overriding aorta, (3)
infundibular pulmonary stenosis, and (4) right
ventricular hypertrophy.
Answer A is incorrect. Atrial septal defects typically
are not clinically apparent until adulthood,
when a patient experiences Eisenmenger’s
syndrome, a reversal of blood fl ow
caused by pulmonary hypertension.
Answer B is incorrect. Patent ductus arteriosus
typically is not clinically apparent until adulthood,
when a patient experiences Eisenmenger’s
syndrome, a reversal of blood fl ow
caused by pulmonary hypertension.
Answer D is incorrect. Transposition of the
great vessels is a condition that leads to early
cyanosis, but it is not as common as tetralogy
of Fallot.
Answer E is incorrect. Ventricular septal defects
(VSDs) are the most common cardiac
congenital defects, but they do not present
with early cyanosis. Infants with larger VSDs
present with tachypnea, dyspnea, and feeding
diffi culties. In addition, they have other signs
of breathing diffi culties such as subcostal or
intercostals retractions and a hyperdynamic
precordium (brisk, quick movement of the thorax).
A holosystolic murmur may be heard on
auscultation.
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