sexta-feira, fevereiro 12, 2010
Nós, que odiamos tanto o PISA.
Evaluation of the zone of flow convergence proximal to the regurgitant valve, using the proximal isovelocity surface area (PISA) method, is a terrific concept but thus far a disappointing clinical tool.
In theory, flow accelerating toward a regurgitant orifice will form a series of concentric isovelocity shells, each smaller in surface area and higher in velocity as they approach the orifice. If the orifice is a very small circle, the shells will be hemispheres. By calculating the shell area (from its radius) and multiplying by its velocity (the color Doppler aliasing velocity), the regurgitant flow rate and effective regurgitant orifice area (EROA) can be calculated.3 Unfortunately, clinically encountered MR is usually associated with an irregularly shaped regurgitant orifice, and the PISA shape is often not hemispheric.
Journal of the American Society of Echocardiography
Issue: Volume 23(1), January 2010, p 9–12
Little, Stephen H. MD, FASE
Methodist DeBakey Heart & Vascular Center, Houston, Texas
O cálculo do PISA é uma pergunta obrigatória na prova do título, fora isso, nunca vi muita utilidade.
Ensino por obrigação para os residentes e alunos.
Não estou sozinho nessa avaliação.