Noninvasive assessment of left-to-right shunting in ventricular septal defects by the proximal isovelocity surface area method on Doppler colour flow mapping

BACKGROUND AND AIM: The proximal isovelocity surface area (PISA), which is the zone of flow convergence appearing on the left ventricular septal surface where flow approaching the defect accelerates; allows quantitative estimation of ventricular septal defect (VSD) flow and defect area on colour Doppler imaging. In the present study, the clinical applicability and reliability of the PISA method in assessing the amount of left-to-right shunting in patients with VSDs were evaluated