The assessment of mitral regurgitation severity frequently involves determining the effective regurgitant orifice area (EROA). One method for estimating EROA utilizes the proximal isovelocity surface area (PISA) technique. This technique relies on measuring the radius of the hemispheric flow convergence zone proximal to the regurgitant mitral valve. By applying established formulas that incorporate the measured radius and the aliasing velocity, the regurgitant flow rate and subsequently the EROA can be derived.
Accurate quantification of mitral regurgitation is critical for clinical decision-making, including guiding medical management and determining the need for surgical intervention. The PISA method provides a non-invasive approach for estimating the severity of mitral regurgitation using echocardiography. While simplified geometric assumptions inherent in the PISA method exist, its widespread adoption reflects its utility and relative ease of implementation in clinical practice. It is important to note that the technique has its limitations, and the results obtained should be interpreted in conjunction with other clinical and echocardiographic parameters.
