USMLE-Rx Step 1 Qmax Challenge #1690

Check out today’s Step 1 Qmax Question Challenge.

Know the answer? Post it below! Don’t forget to check back for an update with the correct answer and explanation (we’ll post it in the comments section below).

USMLE-Rx Step 1 Qmax Challenge #1690A 38-year-old diabetic woman gives birth to a term male infant. Immediately after birth, the infant is cyanotic and tachypneic. A murmur is not auscultated during the newborn screening examination. His hypoxemia quickly worsens over minutes, and a chest radiograph is obtained, which resembles the results shown here for an older child. He undergoes cardiac catheterization, in which a balloon is guided to perforate the atrial septum. He is also given an infusion of prostaglandin E1. An ECG after the procedure demonstrates right-axis deviation and right ventricular hypertrophy. The infant’s hypoxia stabilizes, and he later undergoes definitive, corrective surgery.

Which of the following is the underlying condition responsible for this infant’s hypoxemia?

A. Concomitant ventricular septal defect
B. Pulmonary atresia
C. Tetralogy of Fallot
D. Total anomalous pulmonary venous return
E. Transposition of the great vessels
F. Tricuspid atresia

———————–

Want to know the ‘bottom line?’ Purchase a USMLE-Rx Subscription and get many more features, more questions, and passages from First Aid, including images, references, and other facts relevant to this question.

This practice question is an actual question from the USMLE-Rx Step 1 test bank. For more USMLE Step 1 prep, subscribe to our Flash Facts and Step 1 Express video series. Score the best deal on all three products with USMLE-Rx 360 Step 1.

 

Related Articles