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

What heart condition involves turbulent flow back into the left ventricle during diastole?

1. Coarctation of the aorta

2. Patent ductus arteriosus

3. Aortic regurgitation

4. Mitral stenosis

The correct answer is: Aortic regurgitation

The heart condition characterized by turbulent flow back into the left ventricle during diastole is aortic regurgitation. In this condition, the aortic valve fails to close properly during diastole, allowing blood from the aorta to flow back into the left ventricle. This backflow creates turbulence as the heart refills, resulting in a volume overload of the left ventricle. The mechanism involved in aortic regurgitation leads to distinctive clinical features, such as a diastolic murmur best heard along the left sternal border. Over time, the volume overload on the left ventricle can lead to asymptomatic left ventricular dilation and potential heart failure if the condition progresses without intervention. Other heart conditions mentioned do not involve backflow into the left ventricle during diastole. Coarctation of the aorta primarily affects systemic blood flow and can cause hypertension in the upper body, but it does not cause regurgitation into the left ventricle. Patent ductus arteriosus results in left-to-right shunting of blood from the aorta to the pulmonary artery during systole and diastole, but does not lead to the turbulent flow characteristic of regurgitation. Mitral stenosis