title: Abnormal septal convexity into the left ventricle occurs in subclinical hypertrophic cardiomyopathy.
abstract: BACKGROUND
  Sarcomeric gene mutations cause hypertrophic cardiomyopathy (HCM). In gene mutation carriers without left ventricular (LV) hypertrophy (G + LVH-), subclinical imaging biomarkers are recognized as predictors of overt HCM, consisting of anterior mitral valve leaflet elongation, myocardial crypts, hyperdynamic LV ejection fraction, and abnormal apical trabeculation. Reverse curvature of the interventricular septum (into the LV) is characteristic of overt HCM. We aimed to assess LV septal convexity in subclinical HCM.
  
  
  METHODS
  Cardiovascular magnetic resonance was performed on 36 G + LVH- individuals (31 ± 14 years, 33 % males) with a pathogenic sarcomere mutation, and 36 sex and age-matched healthy controls (33 ± 12 years, 33 % males). Septal convexity (SCx) was measured in the apical four chamber view perpendicular to a reference line connecting the mid-septal wall at tricuspid valve insertion level and the apical right ventricular insertion point.
  
  
  RESULTS
  Septal convexity was increased in G + LVH- compared to controls (maximal distance of endocardium to reference line: 5.0 ± 2.5 mm vs. 1.6 ± 2.4 mm, p ≤ 0.0001). Expected findings occurred in G + LVH- individuals: longer anterior mitral valve leaflet (23.5 ± 3.0 mm vs. 19.9 ± 3.1 mm, p ≤ 0.0001), higher relative wall thickness (0.31 ± 0.05 vs. 0.29 ± 0.04, p ≤ 0.05), higher LV ejection fraction (70.8 ± 4.3 % vs. 68.3 ± 4.4 %, p ≤ 0.05), and smaller LV end-systolic volume index (21.4 ± 4.4 ml/m(2) vs. 23.7 ± 5.8 ml/m(2), p ≤ 0.05). Other morphologic measurements (LV angles, sphericity index, and eccentricity index) were not different between G + LVH- and controls.
  
  
  CONCLUSIONS
  Septal convexity is an additional previously undescribed feature of subclinical HCM.
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. patricia.reant@chu-bordeaux.fr.|Hôpital Cardiologique du Haut-Levêque (Pessac), CHU de Bordeaux, Université de Bordeaux, Bordeaux, France. patricia.reant@chu-bordeaux.fr.
authors.forename: Patricia
authors.initials: P
authors.lastname: Reant
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. gabriella.captur.11@ucl.ac.uk.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Captur
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. mariana.mirabel@inserm.fr.|INSERM U970, Paris Cardiovascular Research Center PARCC, Paris, France. mariana.mirabel@inserm.fr.
authors.forename: Mariana
authors.initials: M
authors.lastname: Mirabel
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. arthurnasis@yahoo.com.au.
authors.forename: Arthur
authors.initials: A
authors.lastname: Nasis
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. dan_sado@yahoo.com.
authors.forename: Daniel
authors.initials: D
authors.lastname: M Sado
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. vivianamaestrini@gmail.com.
authors.forename: Viviana
authors.initials: V
authors.lastname: Maestrini
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. silvia_castelletti@libero.it.
authors.forename: Silvia
authors.initials: S
authors.lastname: Castelletti
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. c.manisty@ucl.ac.uk.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Manisty
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. anna.herrey@bartshealth.nhs.uk.
authors.forename: Anna S
authors.initials: AS
authors.lastname: Herrey
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. p.syrris@ucl.ac.uk.
authors.forename: Petros
authors.initials: P
authors.lastname: Syrris
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. mtome@nhs.net.
authors.forename: Maite
authors.initials: M
authors.lastname: Tome-Esteban
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. sharon.jenkins@bartshealth.nhs.uk.
authors.forename: Sharon
authors.initials: S
authors.lastname: Jenkins
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. perry.elliott@ucl.ac.uk.
authors.forename: Perry M
authors.initials: PM
authors.lastname: Elliott
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. w.mckenna@ucl.ac.uk.
authors.forename: William J
authors.initials: WJ
authors.lastname: McKenna
authors.affiliation: Division of Cardiovascular Imaging and Inherited Cardiac Disease Unit, The Heart Hospital, Institute of Cardiovascular Science, University College London, London, UK. james.moon@bartshealth.nhs.uk.
authors.forename: James C
authors.initials: JC
authors.lastname: Moon
mesh_terms: D000293:Adolescent; D000328:Adult; D058070:Asymptomatic Diseases; D002312:Cardiomyopathy, Hypertrophic / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D016022:Case-Control Studies; D005260:Female; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease; D006352:Heart Ventricles / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D011237:Predictive Value of Tests; D013318:Stroke Volume; D016277:Ventricular Function, Left; D055815:Young Adult
chemical_list: D005819:Genetic Markers