Ace the Ultrasound Registry 2026: Master MV Abnormalities with Confidence!

PISA quantification of mitral regurgitation is based on the hemispheric flow convergence that forms proximal to the regurgitant orifice during systole. The radius is measured at a fixed aliasing velocity when the regurgitant jet is well developed and the flow convergence is stable. That timing is typically mid to late systole, when the regurgitant flow reaches its peak. On the ECG, this corresponds to the period after the QRS complex (ventricular systole) and before systole ends. Diastole and atrial systole are outside when MR occurs, and early systole is usually when the jet is just beginning and less stable for accurate measurement.