Loss of left ventricular rotation is a significant determinant of functional mitral regurgitation

To evaluate insufficient rotational movement of the left ventricle (LV) as a potential novel mechanism for functional regurgitation of the mitral valve (FMR). We compared reference subjects and patients with LV dysfunction (LVD, ejection fraction EF 10 ml). Subjects without structural mitral valve pathology undergoing cardiac MRI were evaluated. Delayed enhancement, global LV remodeling parameters, systolic twist and torsion were measured (using manual and novel automated cardiac MRI tissue-tracking). The study included 117 subjects with mean ± SD age 50.4 ± 17.8 years, of which 30.8% were female. Compared to subjects with LVD without FMR (n = 31), those with FMR (n = 37) had similar clinical characteristics, diagnoses, delayed enhancement, EF, and longitudinal strain. Subjects with FMR had significantly larger left ventricles (EDVi:136.6 ± 41.8 vs 97.5 ± 26.2 ml/m, p