Adult Echocardiography Practice Exam

When severe pulmonic regurgitation is present, where may there be holodiastolic flow reversal?

1. A. right ventricular outflow tract

2. B. left ventricular outflow tract

3. C. main pulmonary artery

4. D. aorta

The correct answer is: C. main pulmonary artery

In cases of severe pulmonic regurgitation, the backflow of blood from the pulmonary artery into the right ventricle during diastole leads to unique hemodynamic changes. Holodiastolic flow reversal is often observed in the main pulmonary artery. This occurs because the increased pressure in the right ventricle during diastole allows blood to flow back into the pulmonary artery from the right ventricle, especially when the regurgitation is significant enough to cause substantial backward flow. The presence of holodiastolic flow reversal in the main pulmonary artery indicates a recognition of the severity of the regurgitation and the dynamic interactions between the right heart and pulmonary circulation. This finding is critical for both the diagnosis and evaluation of the severity of pulmonic regurgitation, as it reflects the direct impact of the regurgitant flow on pulmonary artery dynamics. In contrast, flow reversal is less commonly observed in other structures like the right or left ventricular outflow tracts and the aorta under these pathological conditions, making the main pulmonary artery the most relevant site for detecting this specific hemodynamic change in the context of severe pulmonic regurgitation.