Internal Medicine EOR Practice Exam 2025 – Your Comprehensive All-in-One Guide to Success!

Mitral regurgitation leads to significant hemodynamic changes within the heart, primarily due to the backflow of blood from the left ventricle into the left atrium during systole. This regurgitant flow causes volume overload in both the left atrium and the left ventricle, leading to specific structural adaptations.

The left atrial enlargement occurs because the increased volume of blood returning to the left atrium, as a result of the regurgitation, causes it to dilate over time. The left ventricle also enlarges (dilates) due to the increased volume load it faces as it must accommodate both the normal forward flow of blood and the added volume from the regurgitation. This dilation reflects the heart's compensatory response to manage the altered hemodynamics.

Hypertrophy may occur as a compensatory mechanism as well, but it is primarily the combination of dilation of both the left atrium and the left ventricle that is most characteristic of mitral regurgitation. This structural transformation is significant in understanding the pathology of chronic mitral regurgitation and its potential complications, including heart failure if left untreated.

Other options, like left ventricular hypertrophy, aortic dilation, or thickening of