Which condition is associated with right-to-left shunts?

Right-to-left shunts are conditions where blood flows from the right side of the heart to the left side without passing through the lungs. This results in deoxygenated blood entering the systemic circulation, leading to cyanosis (bluish discoloration of the skin due to low oxygen levels).

Tetralogy of Fallot is characterized by a combination of four defects, one of which is a ventricular septal defect and a right ventricular outflow tract obstruction, both contributing to the right-to-left shunting of blood. This condition typically leads to cyanotic spells due to decreased oxygenation.

Persistent truncus arteriosus is a condition where a single arterial trunk arises from the heart instead of two separate arteries (aorta and pulmonary artery). This defect often leads to mixing of oxygenated and deoxygenated blood due to the presence of a ventricular septal defect, resulting in a right-to-left shunt.

Transposition of the great vessels occurs when the aorta and pulmonary artery are switched, leading to two separate circulations that do not communicate. In some cases, if there are associated defects like a septal defect or patent ductus arteriosus, there can be right-to-left shunting.

Thus, all of these conditions can feature right-to-left