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Isomerism or heterotaxy: which term leads to better understanding?

Published online by Cambridge University Press:  19 June 2015

Rohit S. Loomba ,
Anthony M. Hlavacek ,
Diane E. Spicer  and
Robert H. Anderson
Rohit S. Loomba
Affiliation:
Division of Cardiology, Children’s Hospital of Wisconsin, Milwaukee, Wisconsin, United States of America
Anthony M. Hlavacek
Affiliation:
Division of Pediatric Cardiology, Medical University of South Carolina, Charleston, South Carolina, United States of America
Diane E. Spicer
Affiliation:
Division of Pediatric Cardiology, University of Florida, Gainesville, Florida, United States of America Children’s Heart Institute of Florida, St Petersburg, Florida, United States of America
Robert H. Anderson*
Affiliation:
Division of Pediatric Cardiology, Medical University of South Carolina, Charleston, South Carolina, United States of America Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, United Kingdom
*
Correspondence to: Professor R. H. Anderson, 60 Earlsfield Road, London SW18 3DN, United Kingdom. Tel: +00 44 20 8870 4368; E-mail: sejjran@ucl.ac.uk
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Abstract

Use of correct nomenclature is important in all aspects of medicine. Many of the controversies that have bedeviled paediatric cardiology have devolved from the inappropriate use of words to describe the lesions to be found when the heart is congenitally abnormal. A continuing area of disagreement is the situation currently described by many as representing “heterotaxy”. When used literally, this word means any departure from the normal. Thus, all congenitally malformed hearts represent examples of heterotaxy. By convention, nonetheless, the term is used to describe the arrangement in which the bodily organs, including parts of the heart, are not in their usual or in their mirror-imaged patterns. The arrangements, therefore, represent the presence of the organs on the right and left sides of the body being mirror imaged, in other words isomeric; however, not all the organs are uniformly isomeric. In this review, we show that, when assessed on the basis of the morphology of the atrial appendages, specifically the extent of the pectinate muscles relative to the atrioventricular junctions, isomerism is an unequivocal finding within the heart. Only the atrial appendages, however, are truly isomeric. The potential problem of disharmony between the various systems of organs is resolved simply by accounting specifically for each of the systems. On these bases, we suggest that the isomeric arrangements can now readily be diagnosed in the clinical setting, and differentiated into their right and left isomeric variants. We propose that such distinctions will provide the key for establishing the genetic cues responsible for the formation of the isomeric as opposed to the lateralised arrangements.

Keywords

Splenic syndromesatrial arrangementsequential segmental arrangementmorphological method
Type
Review Articles
Information
Cardiology in the Young , Volume 25 , Issue 6 , August 2015 , pp. 1037 - 1043
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Copyright
© Cambridge University Press 2015 

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References

1. Anderson, RH, Spicer, DE, Hlavacek, AJ, Hill, A, Loukas, M. Describing the cardiac components-attitudinally appropriate nomenclature. J Cardiovasc Transl Res 2013; 6: 118–123.CrossRefGoogle ScholarPubMed
2. Cosio, FG, Anderson, RH, Kuck, KH, et al. Living anatomy of the atrioventricular junctions. A guide to electrophysiologic mapping. A Consensus Statement from the Cardiac Nomenclature Study Group, Working Group of Arrhythmias, European Society of Cardiology, and the Task Force on Cardiac Nomenclature from NASPE. Circulation 1999; 100: e31–e37.CrossRefGoogle Scholar
3. Jacobs, JP, Anderson, RH, Weinberg, PM, et al. The nomenclature, definition and classification of cardiac structures in the setting of heterotaxy. Cardiol Young 2007; 17 (Suppl 2): 1–28.Google Scholar
4. Laux, D, Houyel, L, Bajolle, F, Raimondi, R, Boudjemline, Y, Bonnet, D. Problems in the diagnosis of discordant atrioventricular with concordant ventriculo-arterial connections: anatomical considerations, surgical management and long-term outcome. Cardiol Young 2015 (in press).Google Scholar
5. Van Praagh, R. The segmental approach to diagnosis in congenital heart disease. In Bergsma D (ed.), Birth Defects Original Article Series vol. VIII, No. 5. The National Foundation – March of Dimes, Williams and Wilkins, Baltimore, MD, 1972: 4–23.Google Scholar
6. Ivemark, B. Implications of agenesis of the spleen in the pathogenesis of conotruncus anomalies in childhood. An analysis of the heart; malformations in the splenic agenesis syndrome, with 14 new cases. Acta Paediatr Scand 1955; 44 (Suppl 104): 1–110.Google Scholar
7. Putschar, WGJ, Mannion, WC. Congenital absence of the spleen and associated anomalies. Am J Clin Pathol 1956; 26: 429–470.Google Scholar
8. Van Mierop, LHS, Eisen, S, Schiebler, GL. The radiographic appearance of the tracheobronchial tree as an indicator of visceral situs. Am J Cardiol 1970; 26: 432–435.Google Scholar
9. Landing, BH, Lawrence, TY, Payne, VC Jr, Wells, TR. Bronchial anatomy in syndromes with abnormal visceral situs, abnormal spleen and congenital heart disease. Am J Cardiol 1971; 28: 456–462.Google Scholar
10. Partridge, JB, Scott, O, Deverall, PB, Macartney, FJ. Visualization and measurement of the main bronchi by tomography as an objective indicator of thoracic situs in congenital heart disease. Circulation 1975; 51: 188–196.Google Scholar
11. Cohen, MS, Anderson, RH, Cohen, MI, et al. Controversies, genetics, diagnostic assessment, and outcomes relating to the heterotaxy syndromes. Cardiol Young 2007; 17 (Suppl 2): 29–43.Google Scholar
12. Debich, DE, Devine, WA, Anderson, RH. Polysplenia with normally structured hearts. Am J Cardiol 1990; 65: 1274–1275.Google Scholar
13. Kawakami, R, Dobi, A, Shigemoto, R, Ito, I. Right isomerism of the brain in inversus viscerum mutant mice. PLoS One 2008; 3: e1945.Google Scholar
14. Nagel, BH, Williams, H, Stewart, L, Paul, J, Stumper, O. Splenic state in surviving patients with visceral heterotaxy. Cardiol Young 2005; 15: 469–473.Google Scholar
15. Macartney, FJ, Zuberbuhler, JR, Anderson, RH. Morphological considerations pertaining to recognition of atrial isomerism. Consequences for sequential chamber localisation. Br Heart J 1980; 44: 657–667.CrossRefGoogle ScholarPubMed
16. Van Praagh, R, Van Praagh, S. Atrial isomerism in the heterotaxy syndromes with asplenia, or polysplenia, or normally formed spleen: an erroneous concept. Am J Cardiol 1990; 66: 1504–1506.Google Scholar
17. Uemura, H, Ho, SY, Devine, WA, Kilpatrick, LL, Anderson, RH. Atrial appendages and venoatrial connections in hearts from patients with visceral heterotaxy. Ann Thorac Surg 1995; 60: 561–569.Google Scholar
18. Bamforth, SD, Bragança, J, Farthing, CR, et al. Cited2 controls left-right patterning and heart development through a Nodal-Pitx2c pathway. Nat Genet 2004; 36: 1189–1196.Google Scholar
19. Meno, C, Shimono, A, Saijoh, Y, et al. Lefty-1 is required for left-right determination as a regulator of lefty-2 and nodal . Cell 1998; 94: 287–292.Google Scholar
20. Wolla, CD, Hlavacek, AM, Schoepf, UJ, Bucher, AM, Chowdhury, S. Cardiovascular manifestations of heterotaxy and related situs abnormalities assessed with CT angiography. J Cardiovasc Comput Tomogr 2013; 7: 408–416.Google Scholar
21. Uemura, H, Ho, SY, Devine, WA, Anderson, RH. Analysis of visceral heterotaxy according to splenic status, appendage morphology, or both. Am J Cardiol 1995; 76: 846–849.Google Scholar
22. Li, Y, Klena, NT, Gabriel, GC, et al. Global genetic analysis in mice unveils central role for cilia in congenital heart disease. Nature 2015, doi: 10.1038/nature14269.Google Scholar