Background: Repair of ischaemic mitral incompetence (IMR) by annuloplasty has a high failure rate as it does not directly address leaflet tethering. Strut chordal cutting can relieve leaflet tethering and improve repair durability but impairs left ventricular (LV) function, as does papillary muscle approximation. Although the strut chordae are attached to the body of the anterior leaflet, they align with the trigones and are the structural support for the LV, a function which should be preserved. Papillary-annular shortening has been described but its effect on LV function has not been measured. We aimed to show that the placement of neochords between the papillary tips and ipsilateral trigones to correct papillary displacement could be done without impairment of LV contractility. Methods: Healthy Merino ewes underwent a thoracotomy and normothermic beating heart bypass for insertion of 2 strut neochord loops measured to the length of the anterior marginal chordae and secured 4mm below each papillary tip. A prolene suture attached to the trigonal end of each loop exited the heart through the ipsilateral trigone to allow for reversible papillary-trigonal shortening (P-T S) in an off pump beating heart. Sonocrystals were attached to papillary tips and trigones. A conductance catheter was inserted via the LV apex. Results: Eight sheep (50+1.0Kg) had anterior marginal chordal measurements of 17.5+0.3 mm. Sonocrystal measurements confirmed a mean papillary trigonal shortening of 4.8+0.8mm. Echocardiography showed normal mitral function. Cardiac output and stroke volume were significantly impaired, but there were no statistically significant changes in measurements of contractility associated with P-T S. Conclusion: P-T S does not cause LV contractility impairment in a normal ovine heart. The anterior leaflet marginal chordae offer a useful guide for strut neochord length selection. This may be the optimum subvalvular procedure for repair of IMR.