The purpose of this study is to evaluate a novel paired-ring mitral annuloplasty sizing system in humans.

This is a pilot feasibility study of an investigational device. The proposed device is designed to be used as a temporary, disposable tool that will guide final ring size selection during mitral valve repair surgery. This device enables the direct measurement of the mitral valve opening. Currently, sizing tools for mitral annuloplasty ring implantation has provide only a rough estimate. The field of cardiac surgery is in need of a precise technique to accomplish the important task of correctly selecting an annuloplasty ring for implantation.

Inclusion Criteria:

1. All patients scheduled for mitral repair surgery
2. Age 18 years or older

Exclusion Criteria:

1. Adults unable to consent,
2. Pregnant women and prisoners.
3. Emergency operations and those patients in whom mitral repair is not performed in a meaningful way, requiring mitral replacement instead, will be excluded.
4. Presence of acute endocarditis infection during the initial screening process

Patients undergoing mitral valve repair.