Congenital means inborn or existing at birth. The terms congenital heart defect and congenital heart disease are often used equally, but the word defect is more accurate. A congenital heart defect occurs when the heart or blood vessels near the heart don't develop normally before birth. Congenital heart defects are present in about one percent of live births and are the most frequent congenital malformations in newborns. In most cases scientists don't know why they occur. Sometimes a viral infection causes serious problems. German measles (also called rubella) is an example. If a mother contracts German measles during pregnancy, it can interfere with the development of the baby's heart or produce other malformations. Other viral diseases also may produce congenital defects.

Many types of congenital heart disease can cause major problems starting immediately or soon after birth. Some of them may even lead to irreversible changes that might prevent surgical correction. Therefore, there has been a trend over the years to operate on children with congenital heart disease at earlier ages. Diseases Of The Coronary Arteries Ischemia is a deficiency of blood flow to living tissue or an organ. Many things can cause ischemia. Pinching, cutting or plugging an artery can each cause ischemia by robbing tissue of oxygen-rich blood. Angina is short for angina pectoris, the term for chest pain that arises from insufficient blood flow to the heart muscle. That muscle is continuously active and, consequently, has a large appetite for oxygen. Even a brief reduction of blood flow to it causes pain in most people. The blood vessels in question are called the coronary arteries, which deliver blood to the heart muscle; they are not the vessels that carry blood into and out of the heart's pumping chambers. Ischemia in the three coronary arteries is usually caused by the accumulation of cholesterol, calcium and excess cells on the vessel's inner walls, a process called atherosclerosis. Prolonged or severe ischemia can lead to death of the heart muscle served by the narrowed artery. That is called a myocardial infarction, or, in more common parlance, a heart attack.