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Pathophysiology, clinical manifestations, and diagnosis of D-transposition of the great arteries

Authors
David R Fulton, MD
David A Kane, MD
Section Editor
John K Triedman, MD
Deputy Editor
Carrie Armsby, MD, MPH

INTRODUCTION

Transposition of the great arteries (TGA) is a ventriculoarterial discordant lesion in which the aorta arises from the right ventricle and the pulmonary artery from the left ventricle. The most common form of TGA is the dextro type (referred to as D-TGA) in which the ventricles are oriented so that the right ventricle is positioned to the right of the left ventricle and the origin of the aorta is anterior and rightward to the origin of the pulmonary artery (figure 1). The anatomical defect of D-TGA leads to cyanotic heart disease as a result of two parallel circulations. The first sends deoxygenated systemic venous blood to the right atrium and back to the systemic circulation via the right ventricle and aorta, and the second sends oxygenated pulmonary venous blood to the left atrium and back to the lungs via the left ventricle and pulmonary artery.

The pathophysiology, clinical features, and diagnosis of D-TGA of the great arteries will be presented here. The management and outcome of D-TGA are discussed separately. (See "Management and outcome of D-transposition of the great arteries".)

EPIDEMIOLOGY

The prevalence of transposition of the great arteries (TGA) in the United States is estimated to be 4.7 per 10,000 live births [1]. However, a population-based surveillance study of all live births in five counties in Georgia from 1993 and 2005 reported a lower rate of 2.3 per 10,000 live births [2]. TGA accounts for about 3 percent of all congenital heart disease (CHD) disorders and almost 20 percent of all cyanotic CHD defects [2].

EMBRYOLOGY AND PATHOGENESIS

The specific developmental aspects that result in ventriculoarterial discordance in D-transposition of the great arteries (D-TGA) are not fully delineated. It is hypothesized that the morphogenesis of D-TGA is due to the abnormal growth and development of the bilateral subarterial conus. In normal cardiac development, the subaortic conus and subpulmonary conus are present in the first month of gestation as the great arteries are positioned superior to the right ventricle. Typically, the subaortic conus is resorbed at approximately 30 to 34 days into gestation, which allows for migration of the aortic valve inferiorly and posteriorly into its normal position above the left ventricle. Subaortic conal resorption also leads to the characteristic fibrous continuity between the mitral and aortic valve within the left ventricle. The pulmonary valve retains its association with the right ventricle due to the persistence of the subpulmonary conus [3].

In D-TGA, however, the subpulmonary conus is resorbed, which allows for posterior migration of the pulmonary valve and the development of fibrous continuity between the pulmonary and mitral valve. The unabsorbed subaortic conus forces the aortic valve anteriorly where it abnormally engages with the morphologic right ventricle. The range in the size and orientation of the subaortic conus is thought to create much of the variability of the coronary arteries’ origins and course [4].

              

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Literature review current through: Nov 2016. | This topic last updated: Mon Jan 04 00:00:00 GMT+00:00 2016.
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References
Top
  1. Centers for Disease Control and Prevention (CDC). Improved national prevalence estimates for 18 selected major birth defects--United States, 1999-2001. MMWR Morb Mortal Wkly Rep 2006; 54:1301.
  2. Reller MD, Strickland MJ, Riehle-Colarusso T, et al. Prevalence of congenital heart defects in metropolitan Atlanta, 1998-2005. J Pediatr 2008; 153:807.
  3. Fulton DR, Fyler DC. D-Transposition of the Great Arteries. In: Nadas’ Pediatric Cardiology, 2nd ed, Keane JF, Lock JE, Fyler DC (Eds), Saunders Elsevier, Philadelphia, PA 2006. p.645.
  4. Wernovsky G. Transposition of the Great Arteries. In: Moss and Adams' Heart Disease in Infants, Children, and Adolescents: Including the Fetus and Young Adult, 7th ed, Allen HD, Shaddy RE, Driscoll DJ, Feltes TF (Eds), Wolters Kluwer Health/Lipincott Williams & Wilkins, Philadelphia, PA 2008. p.1039.
  5. Ryan AK, Goodship JA, Wilson DI, et al. Spectrum of clinical features associated with interstitial chromosome 22q11 deletions: a European collaborative study. J Med Genet 1997; 34:798.
  6. Momma K. Cardiovascular anomalies associated with chromosome 22q11.2 deletion syndrome. Am J Cardiol 2010; 105:1617.
  7. McElhinney DB, Clark BJ 3rd, Weinberg PM, et al. Association of chromosome 22q11 deletion with isolated anomalies of aortic arch laterality and branching. J Am Coll Cardiol 2001; 37:2114.
  8. Becker TA, Van Amber R, Moller JH, Pierpont ME. Occurrence of cardiac malformations in relatives of children with transposition of the great arteries. Am J Med Genet 1996; 66:28.
  9. Tennstedt C, Chaoui R, Körner H, Dietel M. Spectrum of congenital heart defects and extracardiac malformations associated with chromosomal abnormalities: results of a seven year necropsy study. Heart 1999; 82:34.
  10. Moene RJ, Oppenheimer-Dekker A, Bartelings MM. Anatomic obstruction of the right ventricular outflow tract in transposition of the great arteries. Am J Cardiol 1983; 51:1701.
  11. Kirklin JW, Barratt-Boyes BG. Complete Transposition of the Great Arteries. In: Cardiac Surgery, Kirklin JW, Barratt-Boyes BG (Eds), Churchill Livingston, New York 1993. p.1383.
  12. Deal BJ, Chin AJ, Sanders SP, et al. Subxiphoid two-dimensional echocardiographic identification of tricuspid valve abnormalities in transposition of the great arteries with ventricular septal defect. Am J Cardiol 1985; 55:1146.
  13. Huhta JC, Edwards WD, Danielson GK, Feldt RH. Abnormalities of the tricuspid valve in complete transposition of the great arteries with ventricular septal defect. J Thorac Cardiovasc Surg 1982; 83:569.
  14. Moene RJ, Oppenheimer-Dekker A. Congenital mitral valve anomalies in transposition of the great arteries. Am J Cardiol 1982; 49:1972.
  15. Wernovsky G, Sanders SP. Coronary artery anatomy and transposition of the great arteries. Coron Artery Dis 1993; 4:148.
  16. Friedberg MK, Silverman NH, Moon-Grady AJ, et al. Prenatal detection of congenital heart disease. J Pediatr 2009; 155:26.
  17. Gottlieb D, Schwartz ML, Bischoff K, et al. Predictors of outcome of arterial switch operation for complex D-transposition. Ann Thorac Surg 2008; 85:1698.