Functional tricuspid valve regurgitation(TR) is often secondary to left-sided valvular heart diseases.The precise diagnosis of TR degree and reasonable treatment can improve the long-term prognosis of patient. Now we believe that rectifying the TR during leftcardiac valve surgery can prevent a further development of TR and avoid the reducing of the cardiac function for patients with moderate TR, tricuspid valve annulus diameter>40 mm in late diastole,tricuspid valve diameter/body surface area>21 mm/m2, and ...