Congenital heart disease comprises a wide spectrum of heart defects which may be present at the time of a person’s birth.
The most common type of congenital defect is a hole in the heart. This may occur between the two atria (an atrial septal defect) or between the two ventricles (a ventricular septal defect). Both conditions typically present themselves in the form of heart murmurs which are abnormal sounds produced by turbulence in the flow of blood through the heart. A ventricular septal defect is generally more serious than an atrial septal defect and, unless the hole in question is very tiny, must be repaired.
Other examples of congenital heart disease include aortic stenosis and Tetralogy of Fallot. In patients with the former condition, the aortic valve (i.e. the valve which separates the left ventricle from the aorta) is unusually narrow. The left ventricle therefore has to work harder to pump blood through the narrowed valve. Where the constriction is severe, the supply of oxygenated blood to other parts of the body may be considerably reduced.
As for Tetralogy of Fallot, it is a condition arising from several different malformations of the heart, namely: the narrowing of the pulmonary valve (pulmonary stenosis); a hole in the wall between the ventricles (a ventricular septal defect); and the “overriding” by the aorta of the hole between the ventricles. As a result, the aorta receives blood from both the left and right ventricles.
This in turn means that the blood which is pumped out of the heart for distribution to other organs is a mixture of oxygenated and deoxygenated blood, and not oxygenated blood alone. Tetralogy of Fallot is usually detected via the characteristic bluish tinge of affected infants’ skin, a symptom arising from an insufficient supply of oxygen-rich blood.