HomeCirculationVol. 99, No. 5Evaluation of Regional Differences in Right Ventricular Systolic Function Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBEvaluation of Regional Differences in Right Ventricular Systolic Function Robert H. Anderson Robert H. AndersonRobert H. Anderson Paediatrics National Heart & Lung Institute, Imperial College School of Medicine, Royal Brompton Campus, London, UK Search for more papers by this author Originally published9 Feb 1999https://doi.org/10.1161/circ.99.5.722/cCirculation. 1999;99:722c–725To the Editor:In their recent study on right ventricular function, Geva and colleagues1 indicate that most previous studies have focused on the chamber as a unitary structure. They then present data supporting its traditional division into “sinus” and “infundibular” components. It is disingenuous of these investigators, however, not also to cite the considerable body of evidence that supports the concept that, morphologically, the right ventricle can be analyzed in terms of 3 components, namely, the inlet, the apical trabecular component, and the outlet. The ring of anatomic landmarks that they cite as the infundibular boundary is, in fact, far from uniformly present in the normal heart. The moderator band, extending from the septal band to the anterior papillary muscle of the tricuspid valve, is but one of the many coarse trabeculations to be found in the apical component. Equally important are the septoparietal bands, identified by Goor and Lillehei2 when they proposed the important tripartite approach to right ventricular structure.There is just as much, if not more, anatomic and embryological evidence to support this tripartite approach as that cited by Geva et al1 in substantiating their bipartite concept. Thus, division of the ventricle is equally well explained in tripartite fashion. The rudimentary right ventricle in double-inlet left ventricle and tricuspid atresia is separated from the dominant left ventricle by the remnant of the apical trabecular septum rather than the infundibular septum. It is this apical muscular septum that carries the atrioventricular conduction axis,3 conduction tissue never being found in the muscular outlet septum. Immunostaining has shown that the conduction axis develops astride this apical muscular septum from the outset.4 The ventricular outflow tracts are divided by the outflow ridges and then give rise to the muscular outlet septum in malformed hearts, but with no relationship to the conduction tissues.5 In the normal heart, however, these ridges are muscularized to form the free-standing subpulmonary infundibulum, the anatomic feature that makes it possible for the surgeon to remove the pulmonary valve as an autograft and use it in the Ross procedure. This would not be possible if the “infundibular septum” was positioned as shown by Geva et al.1 To have presented their results without any discussion of a potentially tripartite configuration presents an unduly biased account of right ventricular structure. References 1 Geva T, Powell AJ, Crawford EC, Chung T, Colan SD. Evaluation of regional differences in right ventricular systolic function by acoustic quantification echocardiography and cine magnetic resonance imaging. Circulation.1998; 98:339–345.CrossrefMedlineGoogle Scholar2 Goor DA, Lillehei CW. Congenital Malformations of the Heart. New York, NY: Grune & Stratton; 1975:1–37.Google Scholar3 Anderson RH, Ho SY, Wilcox BR. The surgical anatomy of ventricular septal defects with univentricular atrioventricular connection. J Card Surg.1994; 9:408–426.CrossrefMedlineGoogle Scholar4 Lamers WH, Wessels A, Verbeek FJ, Moorman AFM, Virágh S, Wenink ACG, Gittenberger-de Groot AC, Anderson RH. New findings concerning ventricular septation in the human heart: implications for maldevelopment. Circulation.1992; 86:1194–1205.CrossrefMedlineGoogle Scholar5 de Jong F, Virágh S, Moorman AFM. Cardiac development: a morphologically integrated molecular approach. Cardiol Young.1997; 7:131–146.CrossrefGoogle ScholarcirculationahaCirculationCirculationCirculation0009-73221524-4539Lippincott Williams & WilkinsResponseGeva Tal, MD, Colan Steven D., MD, Powell Andrew J., MD, Chung Taylor, MD, and Crawford Elizabeth C.09021999We thank Dr Anderson for his interest in our article. His views regarding the anatomic partition of the right ventricle have been publishedR1 and are controversial.R2R3 Our article, however, is about regional differences in right ventricular systolic function. A discussion about the different views regarding the anatomic partition of the right ventricle is important but is beyond the scope of our article. Previous Back to top Next FiguresReferencesRelatedDetails February 9, 1999Vol 99, Issue 5 Advertisement Article InformationMetrics Copyright © 1999 by American Heart Associationhttps://doi.org/10.1161/circ.99.5.722/c Originally publishedFebruary 9, 1999 PDF download Advertisement
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