1) Right to left shunts/ Cyanotic heart defects
The heart is made up of four chambers – two on the left and two on the right. Typically, the left and right side of the heart are separate from each other. The left side of the heart delivers oxygen-rich blood from the lungs to the body while the right side of the heart receives oxygen-poor blood from the rest of the body and transports it to the lungs.
However, in right to left shunts, an unusual link between the right and left sides of the heart causes blood to flow from the right to left side of the heart. This reduces the amount of oxygen in the blood circulating in the body, resulting in a bluish tint to the skin (cyanosis).
Tetralogy of Fallot Ebstein’s anomalyPulmonary atresia Tricuspid atresia
2) Left to right shunts
In left to right shunts, there is an unusual link between the right and left sides of the heart which causes blood to flow from the left side of the heart to the right. This results in an excess amount of blood in the right side of the heart and as such, excessive blood flow to the lungs. Patent Ductus Arteriosus (PDA)Atrial septal defectVentricular septal defectAtrio-Ventricular defectAorto-pulmonary window3) Blood flow obstructionThese are conditions where faulty heart valves or blood vessels block the flow of blood in or out of the heart. Mitral valve stenosisCoarctation of AortaCongenital pulmonary stenosisCongenital aortic stenosisInterrupted aortic arch