Which pathophysiologic consequence is most characteristic of mitral regurgitation?

Which pathophysiologic consequence is most characteristic of mitral regurgitation?

• A. Hyperdynamic LV systolic function
• B. Volume depletion
• C. Low-output syndrome
• D. Volume overload

Answer: (D)

Mitral regurgitation creates a backflow of blood from the left ventricle into the left atrium during systole. This regurgitant flow adds extra volume that the ventricle must handle, increasing preload and raising the left ventricular end-diastolic volume. Over time, the ventricle dilates and undergoes eccentric remodeling to accommodate this increased volume, a hallmark of volume overload. The left atrium also becomes volume overloaded from receiving the regurgitated blood, which can lead to atrial dilation and higher pulmonary pressures. Although a hyperdynamic appearance of the ventricle can occur because the regurgitant orifice lowers effective afterload, the defining and most characteristic consequence is the increased volume load—volume overload—imposed on both the LV and LA.

Mitral regurgitation creates a backflow of blood from the left ventricle into the left atrium during systole. This regurgitant flow adds extra volume that the ventricle must handle, increasing preload and raising the left ventricular end-diastolic volume. Over time, the ventricle dilates and undergoes eccentric remodeling to accommodate this increased volume, a hallmark of volume overload. The left atrium also becomes volume overloaded from receiving the regurgitated blood, which can lead to atrial dilation and higher pulmonary pressures.

Although a hyperdynamic appearance of the ventricle can occur because the regurgitant orifice lowers effective afterload, the defining and most characteristic consequence is the increased volume load—volume overload—imposed on both the LV and LA.