American Board of Internal Medicine (ABIM) Certification Practice Exam

In the context of mild mitral regurgitation, what is the range for the effective regurgitant orifice (ERO)?

1. Less than 0.10 cm2

2. 0.10-0.40 cm2

3. 0.40-0.60 cm2

4. 0.40-0.70 cm2

The correct answer is: Less than 0.10 cm2

In the context of mild mitral regurgitation, the effective regurgitant orifice (ERO) is typically less than 0.10 cm². The ERO is a crucial measurement in assessing the severity of mitral regurgitation, as it quantifies the area through which regurgitant flow occurs. When the ERO is under 0.10 cm², it indicates that the regurgitation is minimal and is generally considered consistent with mild mitral regurgitation. Understanding this parameter is vital for clinicians because it helps inform treatment decisions and follow-up strategies. As the severity of mitral regurgitation increases, the ERO size also increases, correlating with worsening symptoms and changes in the left atrium and ventricle. Values greater than 0.10 cm² typically indicate more significant regurgitation, which can necessitate different management approaches. Therefore, in assessing mild mitral regurgitation, recognizing that an ERO of less than 0.10 cm² signifies a mild condition is essential for proper cardiovascular evaluation and care.