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Figure 1 Principles of PISA Methods
Case example of a 17-year-old patient with severe dilated cardiomyopathy and functional MR. (A, top) The PISA-VTI method; midsystolic PISA at a Nyquist setting of –15.4 cm/s in 4-chamber view with PISA radius r for calculation of MRSV (14.9 ml) (right). (A, bottom) Continuous-wave Doppler spectrum of regurgitant flow with determination of peak velocity (Vmax) and VTI. (B) Serial PISA method. Six serial PISAs throughout systole at a frame rate of 18 frames/s, with calculated MRSV of 22.2 ml (right). Note the decrease of PISA size in midsystole. (C) M-mode PISA method. M-mode registration of PISA with typical midsystolic trough. The gray curved line indicates the leaflet level. The white box illustrates volumetry of the M-mode PISA by method of discs (using Philips EnConcert offline analysis software, Philips Medical Systems, Andover, Massachusetts) to derive r2
mean. Calculated MRSV was 27.9 ml. Length (PISA) = length of M-mode proximal isovelocity surface area in cm; MR = mitral regurgitation; MRSV = mitral regurgitant stroke volume; PISA = proximal isovelocity surface area; t (PISA) = time of mitral regurgitation duration in seconds; Vol (PISA) = M-mode proximal isovelocity surface area volume in ml; VTI = velocity–time integral.
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