Festa et al developed a simple equation for estimating the percent pulmonary regurgitation in patients with surgically-repaired Tetralogy of Fallot. This is based on the Pulmonary Regurgitation Index by M-mode Echocardiography (PRIME). The authors are from CNR-Reg Toscana Fondazione Gabriele Monasterio in Massa-Pisa, Italy.


Patient selection: surgically-repaired tetralogy of Fallot


Method: M-mode echocardiography



(1) diameter of pulmonary artery during systole in cm (to at least 2 decimal points)

(2) diameter of pulmonary artery during diastole in cm



= (diameter during systole) / (diameter during diastole)


pulmonary regurgitation fraction =

= 51.5 / (1 + EXP((-1) * X))


X =

= (8.94 * ((PRIME) - 1.26))


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