Registered Cardiovascular Invasive Specialist (RCIS) Practice Test

How is right atrial pressure primarily influenced in mitral regurgitation?

1. By systemic vascular resistance

2. Through ventricular stiffness

3. Via increased volume return

4. By vascular compliance

The correct answer is: Via increased volume return

In mitral regurgitation, the primary influence on right atrial pressure comes from increased volume return. This condition occurs when the mitral valve does not close properly during ventricular contraction, allowing some blood to flow back into the left atrium from the left ventricle. As a result, the left atrium experiences increased volume and pressure, which can subsequently back up into the pulmonary circulation, increasing pressure there. This increased pressure can lead to higher volume return to the right side of the heart, particularly affecting the right atrium. The elevated volume entering the right atrium contributes to higher right atrial pressure. Therefore, the dynamics of increased return of blood due to the backflow from the left atrium play a critical role in influencing right atrial pressure in this context, making this option the most accurate in explaining the mechanism at work in mitral regurgitation. Other factors, while they may contribute to hemodynamics, do not primarily govern the increase in right atrial pressure associated with this condition.