title: Clinical implications of mitral valve geometric alterations in children with dilated cardiomyopathy.
abstract: We aimed to elucidate the relationship between severity of secondary mitral regurgitation and mitral valve geometry in children with dilated cardiomyopathy. The medical records of 16 children with dilated cardiomyopathy (median age, 1.2 years; range, 0.4-12.3 years) were reviewed. Mitral valve geometry was evaluated by measuring coaptation depth using echocardiographic apical four-chamber views at the initial presentation. Patients were dichotomised according to the mitral regurgitation severity: patients with moderate or severe secondary mitral regurgitation (n=6) and those with mild secondary mitral regurgitation (n=10). A total of 58 healthy children were considered as normal controls, and a regression equation to predict coaptation depth by body surface area was derived: coaptation depth [mm]=4.37+1.34×ln (body surface area [m2]) (residual standard error, 0.49; adjusted R2, 0.68; p<0.0001). Compared with patients with mild secondary mitral regurgitation, those with moderate or severe secondary mitral regurgitation had significantly larger coaptation depth z-scores (6.4±2.3 versus 1.9±1.4, p<0.005), larger mitral annulus diameter z-scores (3.6±2.6 versus 0.9±1.8, p<0.05), higher left ventricular sphericity index (0.89±0.07 versus 0.79±0.06, p<0.005), and greater left ventricular fraction shortening (0.15±0.05 versus 0.09±0.05, p<0.05). In conclusion, geometric alteration in the mitral valve and the left ventricle is associated with the severity of secondary mitral regurgitation in paediatric dilated cardiomyopathy, which would provide a theoretical background to surgical intervention for secondary mitral regurgitation in paediatric populations.
authors.affiliation: 1Division of Cardiology,National Center for Child Health and Development,The University of Tokyo,Tokyo,Japan.
authors.forename: Taiyu
authors.initials: T
authors.lastname: Hayashi
authors.affiliation: 2Department of Pediatrics,Graduate School of Medicine,The University of Tokyo,Tokyo,Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Inuzuka
authors.affiliation: 2Department of Pediatrics,Graduate School of Medicine,The University of Tokyo,Tokyo,Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shindo
authors.affiliation: 1Division of Cardiology,National Center for Child Health and Development,The University of Tokyo,Tokyo,Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ono
authors.affiliation: 3Division of Cardiovascular Surgery,National Center for Child Health and Development,Tokyo,Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Kaneko
authors.affiliation: 1Division of Cardiology,National Center for Child Health and Development,The University of Tokyo,Tokyo,Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kato
mesh_terms: D002311:Cardiomyopathy, Dilated / Q000150:complications*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D007223:Infant; D007564:Japan; D016014:Linear Models; D008297:Male; D008943:Mitral Valve / Q000000981:diagnostic imaging*; D008944:Mitral Valve Insufficiency / Q000601:surgery*; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012720:Severity of Illness Index
keywords: Dilated cardiomyopathy; children; coaptation depth; mitral regurgitation