Congenital Heart Defects
A congenital heart defect is a malformation that occurs during the development of the heart and is present at birth. In eight out of 1,000 births congenital heart defects are present, affecting 30,000 children per year. Some of these defects are mild and only need to be observed. Others are more severe and need surgery soon after birth. Those defects requiring open-heart surgery will require the use of a heart lung machine (bypass machine) to circulate and oxygenate the blood while the heart is stopped during repair. Closed heart surgery is done while the heart is beating and does not require the use of a heart lung machine.
Septal defects are holes in the walls that separate the right and left atria (atrial septal defects) or right and left ventricles (ventricular septal defects). Large defects allow enough blood to cross through the opening that the heart grows larger and the child develops symptoms of “congestive heart failure” such as rapid breathing, difficulty feeding and slow weight gain. Surgery is often required to close these defects.
Narrowing of a blood vessel or valve causes a blockage of blood flow called stenosis. Severe blockage of the pulmonary valve (pulmonary stenosis) can elevate blood pressure and thickening of the right ventricle. Similarly aorta valve stenosis increases the workload on the left ventricle and can also cause thickening. Frequently this can be treated during cardiac catheterization with a balloon tipped catheter (tube) which stretches open the narrowed valve. If this is not successful, surgery is then required.
Abnormal Blood Vessels
A Patent Ductus Arteriosus (PDA) is a normal connection between the aorta and pulmonary artery that is required during fetal life and normally closes in the first day after birth. If it remains open it may causes symptoms of congestive heart failure or infection. It may be closed surgically during a closed heart procedure or with coil embolization during cardiac catheterization.
Coarctation of the aorta is an abnormal narrowing of the main blood vessel of the body. Obstruction of flow can cause high blood pressure in the upper half of the body and leg cramps. During surgery the narrowed area is removed.
Acquired Heart Disease
In contrast to congenital heart disease, acquired heart disease occurs after birth. Some of these are caused by infection such as rheumatic fever or endocarditis. Cardiomyopathy may occur after certain viral infections. Kawasaki’s disease is an inflammatory disease whose cause is unknown.