title: Left Ventricular Noncompaction: Anatomical Phenotype or Distinct Cardiomyopathy?
abstract: There is considerable overlap between left ventricular noncompaction (LVNC) and other cardiomyopathies. LVNC has been reported in up to 40% of the general population, raising questions about whether it is a distinct pathological entity, a remodeling epiphenomenon, or merely an anatomical phenotype.
  
  
  
  The authors determined the prevalence and predictors of LVNC in a healthy population using 4 cardiac magnetic resonance imaging diagnostic criteria.
  
  
  
  Volunteers >40 years of age (N = 1,651) with no history of cardiovascular disease (CVD), a 10-year risk of CVD < 20%, and a B-type natriuretic peptide level greater than their gender-specific median underwent magnetic resonance imaging scan as part of the TASCFORCE (Tayside Screening for Cardiac Events) study. LVNC ratios were measured on the horizontal and vertical long axis cine sequences. All individuals with a noncompaction ratio of ≥2 underwent short axis systolic and diastolic LVNC ratio measurements, and quantification of noncompacted and compacted myocardial mass ratios. Those who met all 4 criteria were considered to have LVNC.
  
  
  
  Of 1,480 participants analyzed, 219 (14.8%) met ≥1 diagnostic criterion for LVNC, 117 (7.9%) met 2 criteria, 63 (4.3%) met 3 criteria, and 19 (1.3%) met all 4 diagnostic criteria. There was no difference in demographic or allometric measures between those with and without LVNC. Long axis noncompaction ratios were the least specific, with current diagnostic criteria positive in 219 (14.8%), whereas the noncompacted to compacted myocardial mass ratio was the most specific, only being met in 61 (4.4%).
  
  
  
  A significant proportion of an asymptomatic population free from CVD satisfy all currently used cardiac magnetic resonance imaging diagnostic criteria for LVNC, suggesting that those criteria have poor specificity for LVNC, or that LVNC is an anatomical phenotype rather than a distinct cardiomyopathy.
authors.affiliation: Department of Cardiovascular and Diabetes Medicine, College of Medicine, University of Dundee, Dundee, United Kingdom.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Weir-McCall
authors.affiliation: Department of Cardiovascular and Diabetes Medicine, College of Medicine, University of Dundee, Dundee, United Kingdom.
authors.forename: Phey Ming
authors.initials: PM
authors.lastname: Yeap
authors.affiliation: Department of Cardiovascular and Diabetes Medicine, College of Medicine, University of Dundee, Dundee, United Kingdom.
authors.forename: Carla
authors.initials: C
authors.lastname: Papagiorcopulo
authors.affiliation: Department of Cardiovascular and Diabetes Medicine, College of Medicine, University of Dundee, Dundee, United Kingdom.
authors.forename: Kerrie
authors.initials: K
authors.lastname: Fitzgerald
authors.affiliation: NHS Tayside Medical Physics, Ninewells Hospital, Dundee, United Kingdom.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Gandy
authors.affiliation: Department of Cardiovascular and Diabetes Medicine, College of Medicine, University of Dundee, Dundee, United Kingdom.
authors.forename: Matthew
authors.initials: M
authors.lastname: Lambert
authors.affiliation: Department of Cardiovascular and Diabetes Medicine, College of Medicine, University of Dundee, Dundee, United Kingdom.
authors.forename: Jill J F
authors.initials: JJ
authors.lastname: Belch
authors.affiliation: NHS Tayside Medical Physics, Ninewells Hospital, Dundee, United Kingdom.
authors.forename: Ian
authors.initials: I
authors.lastname: Cavin
authors.affiliation: Department of Cardiovascular and Diabetes Medicine, College of Medicine, University of Dundee, Dundee, United Kingdom.
authors.forename: Roberta
authors.initials: R
authors.lastname: Littleford
authors.affiliation: NHS Tayside Medical Physics, Ninewells Hospital, Dundee, United Kingdom.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Macfarlane
authors.affiliation: Department of Cardiovascular and Diabetes Medicine, College of Medicine, University of Dundee, Dundee, United Kingdom.
authors.forename: Shona Z
authors.initials: SZ
authors.lastname: Matthew
authors.affiliation: NHS Tayside Medical Physics, Ninewells Hospital, Dundee, United Kingdom.
authors.forename: R Stephen
authors.initials: RS
authors.lastname: Nicholas
authors.affiliation: Department of Cardiovascular and Diabetes Medicine, College of Medicine, University of Dundee, Dundee, United Kingdom.
authors.forename: Allan D
authors.initials: AD
authors.lastname: Struthers
authors.affiliation: Department of Research and Innovation, North York General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Frank
authors.initials: F
authors.lastname: Sullivan
authors.affiliation: NHS Tayside Medical Physics, Ninewells Hospital, Dundee, United Kingdom.
authors.forename: Shelley A
authors.initials: SA
authors.lastname: Waugh
authors.affiliation: Department of Clinical Radiology, University Hospital of Wales, United Kingdom.
authors.forename: Richard D
authors.initials: RD
authors.lastname: White
authors.affiliation: Department of Cardiovascular and Diabetes Medicine, College of Medicine, University of Dundee, Dundee, United Kingdom. Electronic address: ghouston@nhs.net.
authors.forename: J Graeme
authors.initials: JG
authors.lastname: Houston
mesh_terms: D000328:Adult; D009202:Cardiomyopathies / Q000175:diagnosis*; D003937:Diagnosis, Differential; D004452:Echocardiography; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D056830:Isolated Noncompaction of the Ventricular Myocardium / Q000175:diagnosis*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012189:Retrospective Studies
keywords: anatomy; cardiomyopathy; diagnostic; left ventricular noncompaction; magnetic resonance imaging