Dr Ira Shah
Consultant Pediatrician - B.J.Wadia Hospital for Children
Editor - Pediatric Oncall

What is tricuspid atresia?
The heart consists of 4 chambers - the right and left atrium (These are the chambers that receive the blood - the right atrium receives impure blood from the rest of the body and left atrium receives pure blood from the lungs) and the right and left ventricles (These are the chambers that pump the blood from the heart - right ventricle receives impure blood from right atrium and sends it to the lungs and left ventricle receives pure blood from left atrium and sends it to the body). Right atrium is separated from the right ventricle by a valve called as tricuspid valve. Left atrium is separated from the left ventricle by a valve called as mitral valve. The function of the valve is to allow blood to flow from each atrium to their respective ventricle. In tricuspid atresia, there is no tricuspid valve. Thus no blood can flow from right atrium to the right ventricle. Thus the right ventricle is small and not fully developed. The impure blood then that reaches the right atrium flows through a hole between the right atrium and left atrium (atrial septal defect) to the left atrium and then to the left ventricle. Thus the left ventricle receives both pure and impure blood. This blood then is sent to the body and certain amount reaches the right ventricle by a hole between the two ventricles (Ventricular Septal Defect) and then to the lungs and from there after it is oxygenated it goes back to the left atrium.