What does transposition of the great arteries involve?

Transposition of the great arteries (TGA) is characterized by a condition where the positions of the aorta and pulmonary artery are switched, leading to atrioventricular and ventriculo-arterial discordance. This means that the aorta arises from the right ventricle while the pulmonary artery originates from the left ventricle. Consequently, this misalignment results in a systemic circulation that does not properly oxygenate blood, as the right side of the heart is sending deoxygenated blood back to the body, while the left side is sending oxygenated blood back to the lungs.

This discordance is the fundamental issue in TGA, requiring surgical intervention, often in the form of an arterial switch operation, to correct the arrangement of these major vessels and restore normal blood flow patterns. The other options pertain to different cardiovascular conditions or anatomical arrangements that do not accurately represent the unique characteristics of transposition of the great arteries.