Adult Echocardiography Practice Exam

The most significant feature of severe mitral regurgitation is the increase in left atrial volume. In this condition, when the mitral valve does not close properly, a portion of the blood that is pumped from the left ventricle into the aorta flows back into the left atrium during systole. This backflow leads to a volume overload in the left atrium, causing it to enlarge over time.

As the regurgitation becomes more severe, the left atrial volume can significantly increase, contributing to various complications, such as atrial fibrillation and an elevated risk of thrombus formation. Monitoring left atrial volume is crucial in assessing the severity of mitral regurgitation and understanding its consequences on overall cardiac function.

Other features, like decreased ejection fraction or left ventricular hypertrophy, may occur in the context of chronic volume overload but are not as immediate or directly related to the mechanics of severe mitral regurgitation. Similarly, pulmonary edema, while associated with advanced heart failure and volume overload states, is more of a consequence than a direct feature of severe mitral regurgitation itself. Thus, the increase in left atrial volume stands out as the most significant and readily identifiable feature in clinical practice.