A 16-year-old boy is referred to your practice for leg claudication. Blood pressure in his right arm is 150/110 mm Hg, while blood pressure in his left leg is 80/60 mm Hg. On auscultation, a systolic murmur best heard over the middle of the upper back is detected. You also find that the patient’s femoral pulses are diminished when compared to his brachial pulses. Which of the following is the most likely diagnosis?
A) Patent ductus arteriosus
B) Ventricular septal defect
C) Coarctation of the aorta
D) Atrial septal defect
E) Tetralogy of Fallot
Correct Answer C. Coarctation of the aorta
Coarctation of the aorta is narrowing of the aorta usually just distal to the origin of the ductus arteriosus and subclavian artery. Patients may complain of epistaxis, head-ache, cold peripheral extremities, and claudication. Absent, delayed, or markedly diminished femoral pulses may also be found. The low arterial pressure in the legs in the face of hypertension in the arm is also a clue to the diagnosis. Chest radiograph in coarctation shows rib notching secondary to the dilated collateral arteries.
Coarctation of the aorta (CoA) is a relatively common defect that accounts for 5-8% of all congenital heart defects. Coarctation of the aorta may occur as an isolated defect or in association with various other lesions, most commonly bicuspid aortic valve and ventricular septal defect (VSD).