transposition of great arteries
Also written as: TGA — transposition of great arteries
Critical congenital heart defect where the aorta and pulmonary artery are switched, creating separate parallel circulatory circuits incompatible with life.
Full Definition
Transposition of the great arteries (TGA) is a cyanotic congenital heart defect characterized by abnormal positioning of the two main arteries leaving the heart, with the aorta arising from the right ventricle and the pulmonary artery from the left ventricle. This anatomical arrangement creates two separate parallel circuits: the systemic circulation carries deoxygenated blood, while the pulmonary circulation carries oxygenated blood that cannot reach the body. Survival depends on mixing between the circuits through associated defects such as atrial septal defects, ventricular septal defects, or patent ductus arteriosus. TGA presents in two forms: simple (intact ventricular septum) and complex (with associated defects). Immediate management includes maintaining ductal patency with prostaglandin E1 and balloon atrial septostomy to improve mixing. Definitive repair typically involves the arterial switch operation performed in early infancy.
Usage
Usage note: Specify simple vs. complex forms and associated defects. Critical condition requiring immediate intervention.
In Context
- "The newborn with transposition of great arteries required immediate balloon atrial septostomy to improve systemic oxygenation." — Cardiac catheterization report
- "Arterial switch operation was successfully performed at 3 weeks of age for complete transposition of great arteries with intact ventricular septum." — Cardiac surgery operative note