No abstract

Introduction Mitral annular disjunction (MAD) is an anatomical variation of the mitral annulus, characterized by an atrial displacement of the leaflet’s hinge points. It is associated with severe ventricular arrhythmias (VA) in mitral valve prolapse (MVP). Purpose The aim of this study was to assess MAD in MVP by echocardiography, analyze the reproducibility of measurements and evaluate its importance for arrhythmic risk stratification along with strain analysis of myocardial deformation. Methods Two hundred and sixty patients with MVP were included. MAD was evaluated and measured by two observers in the parasternal long axis and in the apical views. Myocardial longitudinal strain was analyzed by speckle-tracking. Results Ninety four patients (36.2%) of MVP patients presented MAD. These patients were younger (53.7 ± 15.1 vs 58.4 ± 17.6, p = 0.033) with higher rate of atypical chest pain (21.3% vs 11.5%, p = 0,041) and bileaflet prolapse (50.5% vs 32.3%, p = 0.004). Para-sternal long-axis view was the incidence of choice to detect MAD with a moderate inter-observer concordance (Kappa of 0.55), good correlation (r = 0.69, p < 0.01) and inter-class correlation coefficient (0.82; 0.67 – 0.90). Twenty patients (7.7%) had a history of severe VA. Among them, no difference was noted in terms of presence (35% vs 36.3%, p = 0.911) or length of MAD (11.1 ± 2.5 vs 11.2 ± 3.1, p = 0.937). However, deformation analysis showed reduced global longitudinal strain (18.6 ± 3.1 vs 21.3 ± 3.3%, p = 0.001) and higher mechanical dispersion values (46 ± 13 vs 37.4 ± 12.9 ms, p = 0.002)in comparison to the rest of the MVP population. Conclusion No significant association was found between severe VA and the presence or severity of MAD in MVP patients. Increased mechanical dispersion and reduced global longitudinal strain may be helpful for arrhythmic risk stratification. Abstract P668 Figure. Comparison of MD and GLS