title: Abnormal Mitral Valve Dimensions in Pediatric Patients with Hypertrophic Cardiomyopathy.
abstract: The hearts of patients with hypertrophic cardiomyopathy (HCM) show structural abnormalities other than isolated wall thickening. Recently, adult HCM patients have been found to have longer mitral valve leaflets than control subjects. The aim of the current study was to assess whether children and adolescents with HCM have similar measureable differences in mitral valve leaflet dimensions when compared to a healthy control group. Clinical and echocardiographic data from 46 children with myocardial hypertrophy and a phenotype and/or genotype consistent with sarcomeric HCM were reviewed. Cardiac magnetic resonance imaging studies were evaluated. The anterior and posterior mitral valve leaflet lengths and myocardial structure were compared to 20 healthy controls. The anterior mitral valve was longer in the HCM group than in the control group (28.4 ± 4.9 vs. 25.2 ± 3.6 mm in control patients, p = 0.013) as was the posterior mitral valve leaflet (16.3 ± 3.0 vs. 13.1 ± 2.3 mm for controls <0.0001). There was no correlation between the resting left ventricular outflow tract gradient and anterior mitral valve leaflet length, nor was the anterior mitral valve leaflet longer in those with systolic anterior motion of the mitral valve compared to those without (28.9 ± 6.1 vs. 28.1 ± 4.5 mm, p = 0.61). Children and adolescents with HCM have abnormally long mitral valve leaflets when compared with healthy control subjects. These abnormalities do not appear to result in, or be due to, obstruction to left ventricular outflow. The mechanism of this mitral valve elongation is not clear but appears to be independent of hemodynamic disturbances.
authors.affiliation: Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.|The Variety Children's Heart Centre, University of Manitoba, FE241-685 William Ave, Winnipeg, MB, R3E 0Z2, Canada.
authors.forename: Daryl
authors.initials: D
authors.lastname: Schantz
authors.affiliation: Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: Lee
authors.initials: L
authors.lastname: Benson
authors.affiliation: Department of Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Windram
authors.affiliation: Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: Derek
authors.initials: D
authors.lastname: Wong
authors.affiliation: Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: Andreea
authors.initials: A
authors.lastname: Dragulescu
authors.affiliation: Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.|Department of Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: Shi-Joon
authors.initials: SJ
authors.lastname: Yoo
authors.affiliation: Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: Luc
authors.initials: L
authors.lastname: Mertens
authors.affiliation: Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Friedberg
authors.affiliation: Department of Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: Bahiyah
authors.initials: B
authors.lastname: Al Nafisi
authors.affiliation: Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada. lars.grosse-wortmann@sickkids.ca.|Department of Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada. lars.grosse-wortmann@sickkids.ca.
authors.forename: Lars
authors.initials: L
authors.lastname: Grosse-Wortmann
mesh_terms: D000293:Adolescent; D002170:Canada; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D002648:Child; D004452:Echocardiography; D005260:Female; D006349:Heart Valve Diseases / Q000000981:diagnostic imaging*; D006352:Heart Ventricles / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008943:Mitral Valve / Q000473:pathology*; D012189:Retrospective Studies; D013599:Systole
keywords: Cardiac magnetic resonance; Children; Hypertrophic cardiomyopathy; Mitral valve; Myocardial delayed enhancement