What Is Congenital Heart Disease?

Imperfect development of the heart during fetal life leads to various deformities.  The cause of such deformities is usually unknown, but some times when the mother contracts rubella during he first few first few months of pregnancy, the fetal heart is affected in this way.  

There are many types of abnormalities and some are so severe that they are incompatible with life, the child either being born dead or dying soon after birth.  Less severe deformity of the heart may be compatible with a short period of life; in milder cases still, the normal span of life may be only slightly reduced.  The common types of defect are as follows:

Septal defect:  abnormal openings on the septum separating the atria or ventricles are called atrial septal defect of ventricular septal defect respectively.

Patent ductus arteriosus:  the ductus arteriosus is a normal communication present between the pulmonary artery and aorta which, during fetal life, 'shunts' the blood so that it bypasses the lungs which are not expanded.  Soon after birth this opening normally closes to allow blood to go through the lings, but in some cases it remains open, so causing signs of congenital heart disease.

Pulmonary stenosis:  the pulmonary valve may be blocked so that it obstructs the blood going to the lungs from the right ventricle.  This is commonly associated with other defects such as patent septum between the ventricles, and is in these cases given the name of Fallot's tetralogy.

Coarctation of the aorta:  in this form of congenital lesion there is a marked narrowing of the arch of the aorta so that the flow of blood into the lower part of the body through the normal channel is inadequate.