title: Key Questions Relating to Left Ventricular Noncompaction Cardiomyopathy: Is the Emperor Still Wearing Any Clothes?
abstract: The evidence is increasing that left ventricular noncompaction cardiomyopathy as it is currently defined does not represent a failure of compaction of pre-existing trabecular myocardium found during embryonic development to form the compact component of the ventricular walls. Neither is there evidence of which we are aware to favour the notion that the entity is a return to a phenotype seen in cold-blooded animals. It is also known that when seen in adults, the presence of excessive ventricular trabeculations does not portend a poor prognosis when the ejection fraction is normal, with the risks of complications such as arrhythmia and stroke being rare in this setting. It is also the case that images of "noncompaction" as provided from children or autopsy studies are quite different from the features observed clinically in asymptomatic adults with excessive trabeculation. Our review suggests that the presence of an excessively trabeculated left ventricular wall is not in itself a clinical entity. It is equally possible that the excessive trabeculation is no more than a bystander in the presence of additional lesions such as dilated cardiomyopathy, with the additional lesions being responsible for the reduced ejection fraction bringing a given patient to clinical attention. We, therefore, argue that the term "noncompaction cardiomyopathy" is misleading, because there is neither failure of compaction nor a cardiomyopathic process in most individuals that fulfill widely used diagnostic criteria.
authors.affiliation: Institute of Genetic Medicine, Newcastle University, Newcastle Upon Tyne, United Kingdom; Division of Biomedical Sciences, University College London, London, United Kingdom.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Anderson
authors.affiliation: Department of Medical Biology, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Bjarke
authors.initials: B
authors.lastname: Jensen
authors.affiliation: National Institute for Medical Research, London, United Kingdom.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Mohun
authors.affiliation: William Harvey Research Institute, NIHR Cardiovascular Biomedical Research Unit at Barts, Queen Mary University of London, London, United Kingdom.
authors.forename: Steffen E
authors.initials: SE
authors.lastname: Petersen
authors.affiliation: William Harvey Research Institute, NIHR Cardiovascular Biomedical Research Unit at Barts, Queen Mary University of London, London, United Kingdom.
authors.forename: Nay
authors.initials: N
authors.lastname: Aung
authors.affiliation: William Harvey Research Institute, NIHR Cardiovascular Biomedical Research Unit at Barts, Queen Mary University of London, London, United Kingdom.
authors.forename: Filip
authors.initials: F
authors.lastname: Zemrak
authors.affiliation: Department of Radiology, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: R Nils
authors.initials: RN
authors.lastname: Planken
authors.affiliation: Department of Cardiology, Taunton & Somerset Hospital, Musgrove Park, Taunton, United Kingdom; Biological Physics Group, School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom; University of Bristol, Bristol, United Kingdom. Electronic address: david.maciver@tst.nhs.uk.
authors.forename: David H
authors.initials: DH
authors.lastname: MacIver
mesh_terms: D000818:Animals; D003952:Diagnostic Imaging / Q000379:methods*; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D056830:Isolated Noncompaction of the Ventricular Myocardium / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000502:physiology*