Table 1. Echocardiographic parameters used for grading of tricuspid regurgitation severity [9].

Parameter	Mild	Moderate	Severe
Tricuspid valve	Normal	Normal or abnormal	Abnormal / flail leaflet / poor coaptation
RV/RA/IVC size	Normal	Normal or dilated	Dilated
VC width [mm]	Not defined	Not defined, but <7	>7
PISA radius [mm]	≤5	6–9	>9
Hepatic vein flow	Systolic dominance	Systolic blunting	Systolic reversal

RV indicates right ventricle; RA, right atrium; IVC, inferior vena cava; VC, vena contracta; PISA, proximal isovelocity surface area.