Proximal Isovelocity Surface Area (PISA) is a method employed in echocardiography to quantify the severity of mitral valve leakage. It involves measuring the radius of the hemispherical flow convergence region just upstream of the regurgitant orifice. This measurement, along with the peak velocity within that hemisphere, allows for the calculation of flow rate and, subsequently, the effective regurgitant orifice area (EROA), a key indicator of the degree of valve dysfunction. Software and devices facilitate the calculation of these parameters using the PISA method.
This approach is valuable because it provides a non-invasive means to estimate the severity of valve insufficiency, guiding clinical decision-making regarding medical management, interventional procedures, or surgical repair. Historically, visual assessment and other Doppler techniques were used, but PISA offers a more quantitative and reproducible measurement. Its use has become increasingly important in the evaluation of patients with suspected mitral regurgitation due to its ability to offer an objective assessment of the valve’s function.
