Left atrial dilation due to mitral regurgitation increases the risk of which complication?

• A. Pulmonary edema
• B. Deep vein thrombosis
• C. Renal failure
• D. Hepatic cirrhosis

Answer: (A)

Mitral regurgitation causes blood to flow back from the left ventricle into the left atrium during systole, creating volume and pressure overload in the left atrium. Over time the atrium enlarges to accommodate this extra volume. The elevated left atrial pressure is transmitted back into the pulmonary veins and capillaries, raising hydrostatic pressure in the pulmonary circulation and leading to pulmonary edema. So, left atrial dilation from mitral regurgitation most directly increases the risk of pulmonary edema. Deep vein thrombosis, renal failure, and hepatic cirrhosis are not the direct, immediate consequences of this left-sided pressure overload.