In D-TGA, the aorta arises from the RV and the PA arises from the LV. This ventriculoarterial discordance results in two parallel circulations in which deoxygenated systemic venous blood returns to the RA and is sent back to the systemic circulation via the RV and aorta, while simultaneously, oxygenated pulmonary venous blood returning to the LA is pumped back to the lungs via the LV and PA. Mixing between the two parallel circulations depends upon a PDA and intracardiac communications (eg, a PFO [shown here] and/or VSD [not shown]).
Ao: aorta; LA: left atrium; LV: left ventricle; PA: pulmonary artery; PDA: patent ductus arteriosus; PFO: patent foramen ovale; RA: right atrium; RV: right ventricle; VSD: ventricular septal defect.
