Which of the following is the most likely finding on EKG?

A 3-month-old female infant is brought in because her parents say she will not eat anymore. Upon physical examination, a loud pansystolic murmur is appreciated. The child also appears small for her age, but her records show no maternal or delivery complications.

Which of the following is the most likely finding on EKG?
A . ST segment elevation
B . Right ventricular hypertrophy
C . QT interval elongation
D . Right bundle branch block

Answer: B

Explanation:

The key to this case is understanding that a child who was otherwise healthy but presents with a holosystolic murmur and symptoms of failure to thrive most likely has a VSD. Right ventricular hypertrophy occurs from blood shunting from the high pressure left system to the low pressure right system. This could later lead to Eisenmenger syndrome (ES). ES is defined as the process in which a left-to-right shunt caused by a VSD reverses into a right-to-left shunt due to hypertrophy of the right ventricle.