Abstract 18503: Relationship Between Left Ventricular Fibrosis and Abnormalities of Mitral Annulus in Arrhythmic Mitral Valve Prolapse
Introduction: Mitral valve prolapse (MVP) is characterized by myxomatous leaflets and in those subjects with malignant ventricular arrhythmias the presence of myocardial fibrosis at the level left ventricular inferobasal wall and papillary muscles have been recently demonstrated.
Hypothesis: We investigated the role of morpho-functional abnormalities of the mitral valve that could explain a regional mechanical myocardial stretch.
Methods and Results: Thirty-seven (28 females; median age 43 years) arrhythmic MVP patients with LV late-gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) and no or trivial mitral regurgitation and 18 (7 females; median age 40 years) MVP patients without LGE were investigated by morpho-functional CMR. Mitral annulus disjunction (MAD, median 4.9 mm vs. 0.8, p<0.001), end-systolic (median 41.0 vs. 32.2, p=0.002), prevalence of posterior systolic curling (35, 95%; vs. 3, 17%, p <0.001) and basal-mid LV wall thickness ratio>1.5 (23, 62%; vs. 4, 22% p=0.005) were higher in MVP patients with LGE than in those without. A Spearman’s correlation coefficient was found between MAD and curling (r=0.853, p<.001). A higher prevalence of auscultatory mid-systolic click (26, 70%, vs. 6, 33%, p=0.009) was also noted. Histology of the mitral annulus showed a longer MAD in 50 sudden death victims with MVP and LV fibrosis than in 20 victims without MVP (median 3 mm vs. 1.5, p<0.001).
Conclusions: In our study MAD seems a constant feature of arrhythmic MVP with LV fibrosis. These data could explain that the excessive mobility of the leaflets caused by posterior systolic curling may account for a mechanical stretch of the inferobasal wall and papillary muscles, eventually leading to myocardial hypertrophy and scarring. These mitral annulus abnormalities, together with auscultatory mid-systolic click, may identify MVP patients who would need arrhythmic risk stratification.
Author Disclosures: M. Perazzolo Marra: None. C. Basso: None. M. De Lazzari: None. S. Rizzo: None. A. Cipriani: None. B. Giorgi: None. C. Lacognata: None. I. Rigato: None. F. Migliore: None. K. Pilichou: None. L. Cacciavillani: None. E. Bertaglia: None. A. Frigo: None. B. Bauce: None. D. Corrado: None. G. Thiene: None. S. Iliceto: None.
- © 2016 by American Heart Association, Inc.