Sizing for mitral annuloplasty: where does science stop and voodoo begin?

The implantation of an improperly sized annuloplasty ring may result in an incompetent valve after surgical mitral valve repair. Consequently, the procedure of ring size selection is considered critical. Although a plethora of sizing strategies are described, the opinions on how to select the appropriate ring size differ widely and often appear arbitrary (ie, without scientific justification). These inconsistencies raise the question where, with respect to ring sizing, science stops and voodoo begins.