A 4-year-old, apparently healthy child is examined by a pediatrician. The pediatrician hears a loud systolic ejection murmur with a prominent systolic ejection click. He also hears a soft, early diastolic murmur. Both murmurs are heard best at the upper right sternal border. ECG shows left ventricular hypertrophy. Which of the following is the most likely diagnosis?
A. Aortic valve stenosis
B. Atrial septal defect
C. Tetralogy of Fallot
D. Transposition of great arteries
E. Ventricular septal defect
Explanation: The correct answer is A. This is aortic valve stenosis, which accounts for 5% of diagnosed cardiac defects, but may actually be the most common congenital anomaly of the heart since many minor cases are never diagnosed. Most cases are due to bicuspid aortic valves, and characteristically produce a systolic ejection murmur. An accompanying aortic insufficiency may produce an early diastolic murmur. The timing of surgical correction depends on the severity of the individual case.
Atrial septal defect (choice B) causes a murmur heard best at the left upper sternal border.
Tetralogy of Fallot (choice C) and transposition of great arteries (choice D) usually present in infancy.
Ventricular septal defect (choice E) causes a murmur heard best at the lower left sternal border.