What occurs in Transposition of the great arteries?

In Transposition of the Great Arteries (TGA), the primary issue is that the aorta and pulmonary artery are indeed reversed or transposed. This means that the aorta arises from the right ventricle instead of the left, and the pulmonary artery arises from the left ventricle instead of the right. As a result, two separate and parallel circulatory systems exist: one circulation goes from the heart to the body and back (systemic circulation) without passing through the lungs, while the other circulates through the lungs but does not supply blood to the body.

This abnormal arrangement results in inadequate oxygenation of blood since the blood returning from the body does not get oxygenated in the lungs before being pumped back to the systemic circulation. The clinical implications of this condition can be severe and often require surgical intervention or other treatment modalities to establish proper blood circulation.

In this context, the other options may involve criteria that can be associated with different cardiac conditions or anatomical issues but do not accurately describe the fundamental defect that occurs in Transposition of the Great Arteries. Understanding this critical aspect of TGA is vital for recognizing the urgency of diagnosis and treatment.