(A) 2D polar maps of radial strain with AHA segmentation representing time to peak of each segment with plots (below) depicting the time to peak radial strain of individual chords (cvi42®). (B) Septal-lateral segment difference was better in TBX18 pigs one month following AV block (115±10ms GFP, 53±15ms TBX18, P=0.001) (C) Representative post processed MRI (cvi42®) identifying end diastolic (top) and end systolic (bottom) phases (D) Endpoint ejection fraction was higher in TBX18 animals (46.75±2% GFP, 58.5±1.3% TBX18, p=0.001). (E-F) Additionally, TBX18 pigs demonstrated lower end systolic (61.1±1.2ml GFP, 52±3ml TBX18 p=0.04) and end diastolic volume (123±3ml GFP, 110±5ml TBX18, p=0.1)