Repeated USMLE Questions Step 1- 192

An 18 year-old student visits her physician for a routine physical examination. She has no complaints. Physical examination is unremarkable except for a mid-systolic click followed by a late systolic murmur heard at the lower left sternal border and apex. The murmur duration increases in standing and shortens with squatting. Electrocardiogram (ECG) shows no abnormalities.

Which of the following is the most likely diagnosis of this condition?

A- Mitral stenosis

B- Aortic stenosis

C- Mitral valve prolapse

D- Tricuspid regurgitation

E- Dilated cardiomyopathy

Answer






The only diagnosis that matches the described murmur is mitral valve prolapse. Patients with MVP are usually asymptomatic and only diagnosed accidently or due to progress to mitral regurgitation. Normal ECG findings support this diagnosis. Mitral valve prolapse is confirmed by echocardiography.

The correct answer is C