Abstract: Adjustable, flexible mitral and tricuspid annuloplasty rings having internal drawstrings that emerge from the rings on the annular faces so that the drawstring knots are out of the bloodstream, the drawstrings being contained in clearly marked channels, the mitral ring having a curved semi-flexible stiffener member in the anterior segment to maintain intertrigonal distance during implantation, the plane of the anterior segment lying at an angle of about 30.degree.-75.degree. to the plane of the posterior segment, arcing up across the anterior leaflet to prevent outflow tract obstruction.