title: The hypertrabeculated (noncompacted) left ventricle is different from the ventricle of embryos and ectothermic vertebrates.
abstract: Ventricular hypertrabeculation (noncompaction) is a poorly characterized condition associated with heart failure. The condition is widely assumed to be the retention of the trabeculated ventricular design of the embryo and ectothermic (cold-blooded) vertebrates. This assumption appears simplistic and counterfactual. Here, we measured a set of anatomical parameters in hypertrabeculation in man and in the ventricles of embryos and animals. We compared humans with left ventricular hypertrabeculation (N=21) with humans with structurally normal left ventricles (N=54). We measured ejection fraction and ventricular trabeculation using cardiovascular MRI. Ventricular trabeculation was further measured in series of embryonic human and 9 animal species, and in hearts of 15 adult animal species using MRI, CT, or histology. In human, hypertrabeculated left ventricles were significantly different from structurally normal left ventricles by all structural measures and ejection fraction. They were far less trabeculated than human embryonic hearts (15-40% trabeculated volume versus 55-80%). Early in development all vertebrate embryos acquired a ventricle with approximately 80% trabeculations, but only ectotherms retained the 80% trabeculation throughout development. Endothermic (warm-blooded) animals including human slowly matured in fetal and postnatal stages towards ventricles with little trabeculations, generally less than 30%. Further, the trabeculations of all embryos and adult ectotherms were very thin, less than 50 μm wide, whereas the trabeculations in adult endotherms and in the setting of hypertrabeculation were wider by orders of magnitude. It is concluded in contrast to a prevailing assumption, the hypertrabeculated left ventricle is not like the ventricle of the embryo or of adult ectotherms. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.
authors.affiliation: Department of Anatomy, Embryology & Physiology, Academic Medical Center, University of Amsterdam, The Netherlands. Electronic address: b.jensen@amc.uva.nl.
authors.forename: Bjarke
authors.initials: B
authors.lastname: Jensen
authors.affiliation: Department of Clinical Medicine, Aarhus University Hospital, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Agger
authors.affiliation: Department of Anatomy, Embryology & Physiology, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Bouke A
authors.initials: BA
authors.lastname: de Boer
authors.affiliation: Department of Anatomy, Embryology & Physiology, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Roelof-Jan
authors.initials: RJ
authors.lastname: Oostra
authors.affiliation: MR Research Center, Department of Clinical Medicine, Aarhus University, Denmark.
authors.forename: Michael
authors.initials: M
authors.lastname: Pedersen
authors.affiliation: Department of Pathology, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Allard C
authors.initials: AC
authors.lastname: van der Wal
authors.affiliation: Department of Radiology, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Nils Planken
authors.affiliation: Department of Anatomy, Embryology & Physiology, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Antoon F M
authors.initials: AF
authors.lastname: Moorman
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000818:Animals; D002648:Child; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000196:embryology* / Q000503:physiopathology; D006801:Humans; D056830:Isolated Noncompaction of the Ventricular Myocardium / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009024:Morphogenesis; D009206:Myocardium / Q000473:pathology*; D012189:Retrospective Studies; D013045:Species Specificity; D013318:Stroke Volume; D014057:Tomography, X-Ray Computed; D016277:Ventricular Function, Left; D055815:Young Adult
keywords: Development; Evolution; Heart failure; Noncompaction