American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the volume capacity (VC) indicative of mild aortic regurgitation?

1. Less than 0.3 cm

2. Between 0.3 cm and 0.6 cm

3. Greater than 0.6 cm

4. Exactly 0.3 cm

The correct answer is: Less than 0.3 cm

The volume capacity indicative of mild aortic regurgitation is typically characterized by a stroke volume that exceeds the normal range, leading to an effective regurgitant orifice area that is generally smaller than 0.3 cm. In the context of aortic regurgitation, a smaller orifice area corresponds to a less severe form of the condition, as it indicates that the amount of blood regurgitating back into the left ventricle during diastole is limited. Mild aortic regurgitation generally presents with minimal impact on the patient's hemodynamics and typically does not result in significant left ventricular dilation or dysfunction. A threshold of less than 0.3 cm for the effective regurgitant orifice signifies that the patient is likely experiencing only a mild degree of regurgitation. The option denoting a range of between 0.3 cm and 0.6 cm indicates a moderate level of aortic regurgitation, which would involve greater compensatory adaptations by the heart and potential symptoms. Similarly, a measurement greater than 0.6 cm is indicative of severe aortic regurgitation, implying a significant burden on the cardiovascular system. An exact measurement of 0.3 cm lacks clinical relevance as it does not