USMLE (United States Medical Licensing Examination) Step 1 Practice Exam

Which heart disease causes fatigue, syncope, shortness of breath, and palpitations?

1. Coarctation of the aorta

2. Patent ductus arteriosus

3. Aortic regurgitation

4. Mitral regurgitation

The correct answer is: Mitral regurgitation

The symptoms of fatigue, syncope, shortness of breath, and palpitations align well with mitral regurgitation, which is characterized by the backflow of blood from the left ventricle into the left atrium during systole due to an insufficient mitral valve. This backflow leads to volume overload of the left atrium and subsequent pulmonary circulation congestion. The pulmonary congestion manifests as shortness of breath, particularly during exertion or when lying flat. Additionally, the volume overload can lead to increased pressures in the left atrium, which may trigger arrhythmias, contributing to palpitations and increased fatigability from reduced cardiac output. Syncope may occur due to decreased cerebral perfusion, especially during episodes of significant arrhythmia or reduced cardiac efficiency. While coarctation of the aorta typically presents with hypertension in the upper body and decreased blood flow to the lower body leading to exertional symptoms, patent ductus arteriosus usually results in continuous murmurs or findings associated with volume overload, but not outright syncope or palpitations. Aortic regurgitation does cause volume overload of the left ventricle and can lead to symptoms like fatigue and shortness of breath, but it is often associated with