Attrition Rate in TGA

Attrition rate in TGA 

Transposition of Great Arteries is the most common cyanotic congenital heart disease at birth. It is in fact the first condition to be thought of if cyanosis, especially with heart failure, is detected on day one. It contributes to about five to eight percent of the congenital heart diseases [1] and the survival is poor without early intervention. Untreated, thirty percent of them die in the first week, fifty percent in first month, seventy percent in first six months and ninety percent in the first one year [2]. But there are also rare cases of unusual longevity without surgical intervention and such cases may present in adult life [3].

This happens most often when there is a large atrial septal defect with good mixing of the circulations. It may be noted that pulmonary and systemic circulations are in parallel in transposition of great arteries unlike the series arrangement in normal individuals. Hence good mixing is mandatory for good survival. Mixing at atrial level permits good systemic oxygenation without the development of significant pulmonary hypertension. A balanced shunt with ventricular septal defect and pulmonary stenosis (left ventricular outflow tract obstruction) also may permit survival into adult life without surgery. This can be considered as a tetralogy of Fallot equivalent circulation.

References

1. Carlgren LE. The incidence of congenital heart disease in children born in Goteborg, 1941-1950. Br Heart J 1959;21:40.
2. Liebman J, Cullum L, Belloc NB. Natural history of transposition of the great arteries: anatomy and birth an death characteristics. Circulation 1969;40:237-62.
3. Gallego P, Oliver JM, Benito F, Mesa JM, Sanz E, Moreno I, et al. Unusual longevity without surgical intervention in complete transposition of the great arteries. Pediatr Cardiol 1998;19:358-60.