Quantification of Left-to-Right Shunt in Secundum Atrial Septal Defect by PISA Method

BackgroundThe purpose of this study was to quantitate the degree of left-to-right shunt in patients with secundum atrial septal defect (2o ASD) with the PISA method and compare the results with the usual continuity equation. Although the PISA method has been used extensively for the quantitative measurement of regurgitant severity and valve area in patients with valvular regurgitation and stenosis, its use in patients with left-to-right shunts including ASD is yet to be evaluated extensively. Methods We studied 48 consecutive patients with 2 ASD (mean age: 32.5±4 years; range:18-54 years). Left-to-right shunting was quantified by continuity equation and PISA method. The defect size was between 12 and 40 mm (mean: 26±6). ResultsQP/QS by continuity equation was between 1.7-4.5/1 (mean: 2.91), and by PISA method was between 1.6-4.8/1 (mean: 2.92), [r = 0.92, PV= 0.0001]. There was no significant difference between the degree of shunt estimated by continuity equation and PISA method in terms of the defect size and the degree of shunt (PV = 0.179). Conclusion-The PISA method could be used as an accurate alternative method to the continuity equation for quantitation of the degree of shunt flow in patients with 2 ASD (Iranian Heart Journal 2006; 7 (2):25-30).