Grant et al. 1926 did not provide the first description of left ventricular hypertrabeculation/noncompaction

Abstract

The American and European Societies of Cardiology categorise left ventricular hypertrabeculation/noncompaction (LVHT) as unclassified cardiomyopathy [ [1] Elliott P. Andersson B. Arbustini E. et al. Classification of the cardiomyopathies: a position statement from the European Society Of Cardiology Working Group on Myocardial and Pericardial Diseases. Eur Heart J. 2008; 29: 270-276 Crossref PubMed Scopus (1866) Google Scholar ]. Though the aetiology of LVHT is unknown, it is frequently associated with hereditary neuromuscular disorders (NMDs), hereditary cardiac disease, or chromosomal abnormalities [ [2] Finsterer J. Cardiogenetics, neurogenetics, and pathogenetics of left ventricular hypertrabeculation/noncompaction. Pediatr Cardiol. 2009; 30: 659-681 Crossref PubMed Scopus (189) Google Scholar ]. LVHT refers to a morphological abnormality of the left ventricular myocardium macroscopically characterised by a two-layered structure, of which the epicardial layer is compacted and the endocardial layer non-compacted [ [3] Stöllberger C. Gerecke B. Finsterer J. Engberding R. Refinement of echocardiographic criteria for left ventricular noncompaction. Int J Cardiol. 2013; 165: 463-467 Abstract Full Text Full Text PDF PubMed Scopus (79) Google Scholar ]. The endocardial layer is thicker than the epicardial layer and characterised by a meshwork of interwoven myocardial strings, which are separated by deep intertrabecular recesses and perfused from the ventricular side [ [4] Captur G. Nihoyannopoulos P. Left ventricular non-compaction: genetic heterogeneity, diagnosis and clinical course. Int J Cardiol. 2010; 140: 145-153 Abstract Full Text Full Text PDF PubMed Scopus (98) Google Scholar ]. Histologically, the trabeculations are lined with endocardium and show vacuolisation of cardiomyocytes, abnormal nuclei, increased glycogen storage, and frequently subendocardial fibrosis [ 5 Allenby P.A. Gould N.S. Schwartz M.F. Chiemmongkoltip P. Dysplastic cardiac development presenting as cardiomyopathy. Arch Pathol Lab Med. 1988; 112: 1255-1258 PubMed Google Scholar , 6 Bleyl S.B. Mumford B.R. Brown-Harrison M.C. et al. Xq28-linked noncompaction of the left ventricular myocardium: prenatal diagnosis and pathologic analysis of affected individuals. Am J Med Genet. 1997; 72: 257-265 Crossref PubMed Scopus (289) Google Scholar ]. In LVHT the intertrabecular spaces do not communicate with myocardial arteries, veins, or capillaries, neither with those of the compacted nor with those of the non-compacted layer [ [7] Engberding R. Yelbuz T.M. Breithardt G. Isolated noncompaction of the left ventricular myocardium — a review of the literature two decades after the initial case description. Clin Res Cardiol. 2007; 96: 481-488 Crossref PubMed Scopus (103) Google Scholar ]. There is also no other communication with the coronary artery system. Contrary to LVHT, there are communications between the coronary arteries and the left ventricle in conditions such as persisting sinusoids [ [8] Jenni R. Goebel N. Tartini R. Schneider J. Arbenz U. Oelz O. Persisting myocardial sinusoids of both ventricles as an isolated anomaly: echocardiographic, angiographic, and pathologic anatomical findings. Cardiovasc Intervent Radiol. 1986; 9: 127-131 Crossref PubMed Scopus (155) Google Scholar ] or the snake heart [ [9] Walia I. Arora H.S. Barker E.A. Delgado III, R.M. Frazier O.H. Snake heart: a case of atavism in a human being. Tex Heart Inst J. 2010; 37: 687-690 PubMed Google Scholar ], which may be also associated with hypertrabeculation of the left ventricle. In a number of publications [ 10 Misra C. Garg V. Compacting the heart with Notch. Nat Med. 2013; 19: 133-134 Crossref PubMed Scopus (8) Google Scholar , 11 Brescia S.T. Rossano J.W. Pignatelli R. et al. Mortality and sudden death in pediatric left ventricular noncompaction in a tertiary referral center. Circulation. 2013; 127: 2202-2208 Crossref PubMed Scopus (164) Google Scholar ], LVHT is reported to have been described for the first time by Grant et al. in 1926 [ [12] Grant R.T. An unusual anomaly of the coronary vessels in the malformed heart of a child. Heart. 1926; 13: 273-283 Google Scholar ]. This, however, needs to be revised since the condition described by Grant et al. does not meet the diagnostic criteria of LVHT outlined above.