Which expression correctly defines MR regurgitant volume in terms of effective regurgitant orifice area and the regurgitant jet velocity-time integral?

Which expression correctly defines MR regurgitant volume in terms of effective regurgitant orifice area and the regurgitant jet velocity-time integral?

• A. EROA + MR jet VTI
• B. EROA × MR jet VTI
• C. EROA − MR jet VTI
• D. EROA ÷ MR jet VTI

Answer: (B)

The amount of blood that regurgitates each beat in mitral regurgitation is found by linking orifice size to how far and how long the jet travels. Specifically, regurgitant volume = effective regurgitant orifice area (EROA) × the regurgitant jet velocity-time integral (VTI). This uses the idea that flow through the orifice equals area times velocity, and the VTI represents the distance the jet travels during systole when you integrate velocity over time. Multiplying cm^2 (EROA) by cm (the VTI in distance units) gives cm^3, i.e., milliliters, which is the regurgitated volume per beat. Hence, the correct expression is EROA × MR jet VTI. Other operations would not produce a volume with correct units or physical meaning.

The amount of blood that regurgitates each beat in mitral regurgitation is found by linking orifice size to how far and how long the jet travels. Specifically, regurgitant volume = effective regurgitant orifice area (EROA) × the regurgitant jet velocity-time integral (VTI). This uses the idea that flow through the orifice equals area times velocity, and the VTI represents the distance the jet travels during systole when you integrate velocity over time. Multiplying cm^2 (EROA) by cm (the VTI in distance units) gives cm^3, i.e., milliliters, which is the regurgitated volume per beat. Hence, the correct expression is EROA × MR jet VTI. Other operations would not produce a volume with correct units or physical meaning.