What happens to the left atrial pressure in acute mitral regurgitation?

In acute mitral regurgitation, the left atrial pressure increases due to the sudden volume overload from the regurgitant flow of blood from the left ventricle back into the left atrium during systole. Normally, during ventricular contraction, the mitral valve closes, preventing backflow into the atrium. However, in acute mitral regurgitation, this closure is compromised, leading to an influx of blood into the left atrium.

As a result, the left atrium experiences elevated pressures quickly as it accommodates the excess blood volume. This increased pressure can lead to symptoms such as pulmonary congestion and respiratory distress due to elevated pulmonary venous pressure. Understanding the dynamics of blood flow and pressure changes during this condition is vital for assessing patient status and planning appropriate interventions.