Brussels, Belgium

Definition:

Transposition of the great vessels is one of the most common cardiovascular anomalies. There is a concordant atrioventricular connection and discordant ventriculo- atrerial connection. The aorta is anterior to the pulmonary artery. The aorta takes origin above the morphologically right ventricle and the pulmonary trunk above the morphologically left ventricle. The relentless course of these babies without treatment is death shortly after birth from hypoxemia (1).

Case report:

The following images were obtained during a routine ultrasound examination at 25 weeks. The woman had no personal nor family history of malformations or genetic disorders. No other abnormatity was seen. An amniocentesis was performed. The karyotype was normal and no microdeletion 22q11 was detected.

Figure 1-4: The position of the ventricular septal defect (sd) involves the infudibular septum with a malaligment of the pulmonary artery.

Figure 5-6  : The pulmonary artery (pa) arises from the left ventricle (lv)

Figure 7 : The ascending aorta (Ao) and the pulmonary artery (PA are parallel to each other.

Figure 8 :The aorta (Ao) arises from the anterior, right ventricle (RV)

Incidence:

2.11/10,000 (2), more frequent in boys.

Sonographic findings:

The four chamber-view is normal. The great arteries arise in parallel arrangement. The aorta arise close to the anterior wall from the right ventricle and the pulmonary trunk arise posteriorely from the left ventricle.(3,4)

Types of  heart with complete transposition of great vessels (TGA):

4 types have been described (1)

1. TGA and intact ventricular septum or small ventricular septal defect (74%)
2. TGA and large ventricular septal defect (21%)
3. TGA, ventricular septal defect and pulmonary stenosis (5%)
4. )TGA, intact ventricular septum and pulmonary stenosis (0,7%)

Other Abnormalities:

Usally TGA is an isolated malformation (1,2). Some cases of microdeletion 22q11 can be found. Di George syndrome (velocardiofacial and conotruncal anomaly face syndrome) is include in the CATCH-22 microdeletion complex.

Infants with TGA have normal birth weight but smaller head volume relative to birth weight (5).

Prognosis:

After the initial life-saving maneuver of baloon septotomy (Rashkind and Miller 1966) a second surgical act is needed for the arterial repair (Arterial switch operation with coronary artery relocation) or atrial repair (Mustard operation). The range of mortality is 5-10%. It depends of the degree of pulmonary stenosis and the coronary arterial anomalies.(1,6, 7)

References

1)      R.M. Freedom, L.N. Benson, J.F. Smallhorn. Neonatal heart disease. Springer-Verlag London 1992, p179-212

2)      C.Ferencz, J.D. Rubin, R.J. Mc Carter. Congenital heart disease: prevalence at livebirth. The Baltimore- Washington infant study. Am J Epidemiol 1985 121: 31-36

3)      L. Allan, G. Sharland, A. Cook. Fetal Cardiology. 1994 Mosby-Wolfe.p109-114.

4)      S.J. Yoo, Y.H. Lee, E.S. Kim, H.M. Ryu, M.Y. Kim, H.K. Choi, K.S. Cho, A. Kim. Three-vessel view of the fetal upper mediastinum: an easy means of detecting abnormalities of the ventricular outflow tracts and great arteries during pbstetric screening. Ultrasound Obstet. Gynecol 9 (1997) 173-182.

5)      G.L. Rosenthal. Patterns of prenatal growth among infants with cardiovascular malformations: possible fetal hemodynamic effects. Am J Epidemiol.1996 may15;143 (10) :1079

6)      J.P. Binet, C. Planche. Development of a technique for complete correction of transposition of great vessels. C R seances Soc Biol Fil 1992; 186(4): 401-404.

7)      A. Batisse. Cardiologie pédiatrique pratique. Doin2002, 106-109.