Simplifying proximal isovelocity surface area as an assessment method of mitral valve area in patients with rheumatic mitral stenosis by fixing aliasing velocity and mitral valve angle

UNLABELLED: We aimed to test the ability of a simple equation using proximal isovelocity surface area method (PISA), created by fixing the angle to 100° and the aliasing velocity to 33 cm/s, to calculate mitral valve area (MVA) and assess severity in patients with rheumatic mitral stenosis (MS)