USMLE Step 1 Question 383

Question:

An 13-year-old girl presents for evaluation of short stature (<10th percentile) and absence of breast development. Her mother reports that the patient was the same height as her peers until a few years ago. On physical exam, patient is found to have appropriate pubic hair and normal external female genitalia. There were no other significant findings except for elevated blood pressure in both arms and weak femoral pulses. What is the patient's most likely cardiac defect?

Correct Answer: D.  Coarctation of the aorta

The patient has Turner’s syndrome and thus most likely has coarctation of the aorta. Turner’s syndrome is associated with type I coarctation, which involves narrowing of the aorta distal to the left subclavian but proximal to the insertion of the ductus arteriosus or preductal.

Tetralogy of Fallot includes VSD, pulmonary stenosis, right ventricular hypertrophy, and overriding aorta. This defect is associated with cyanosis and would be diagnosed at a younger age.

Epstein’s anomaly (found in babies of mothers taking lithium in the 1st trimester) is a downward displaced tricuspid valve. This type of congenital heart defect is not associated with cyanosis (similar to coarctation of the aorta), but it is not associated with Turner’s syndrome.

A patent ductus arteriosus is associated with rubella and prematurity, not Turner’s syndrome. A PDA often has a continuous, machine-like murmur. In addition, this defect is associated with the later development of cyanosis. First, there is a left-to-right shunt that then develops into the right to left shunt of Eisenmenger’s.

Eisenmenger’s syndrome is the right to left shunt that develops after an initial left-to-right shunt. It is associated with thickening of the pulmonary artery walls and the common symptoms include cyanosis, clubbing, pulmonary hypertension, and heart failure. The congenital defects that may result in Eisenmenger’s if they are not corrected include VSD, ASD, PDA, persistent truncus arteriosus, and anomalous pulmonary venous drainage. Eisenmenger’s is not associated with coarctation of the aorta or with Turner’s syndrome.