Anomalous left coronary artery (ALCA) occurs when the left coronary artery arises from the pulmonary artery instead of its usual site of origin, the aorta. It is a rare problem comprising <1% of congenital heart defects.

Anomalous pulmonary venous return (APVR) is a rare heart defect that occurs when the pulmonary veins fail to form normally while the baby is in the mother’s womb. It comprises <1% of all congenital heart defects. The cause of the problem is not known.

Aortic stenosis is a term used to describe congenital heart defects that cause obstruction of blood flow from the heart to the body. Significant aortic stenosis is relatively uncommon affecting about 6 of every 1000 babies born and occurs more often in boys. It can occur alone, that is without other heart problems, or in association with bicuspid aortic valve, coarctation of the aorta, ventricular septal defect, mitral valve abnormality, and less commonly with atrial septal defect or complete at

Atrial fibrillation (AF) is an arrhythmia (abnormal heart rhythm) that causes the heart’s upper chambers-the atria- to beat very fast and irregularly. It is quite rare in children but can occur in children with cardiomyopathy, after complex heart surgery, and very rarely, in children with otherwise normal hearts.

Atrial flutter is an abnormal, rapid heart rhythm that comes from the heart’s upper chambers — the atria — causing them to beat at rates of 220 to 300 times a minute. Atrial flutter is uncommon in the young except when there is a history of heart surgery involving the atria. The operations associated with atrial flutter include the Fontan procedure, Mustard or Senning procedure, repair of tetralogy of Fallot, repair of total anomalous venous connection, and repair of atrial septal defect. The

Atrial septal defect (ASD) is the second most common congenital heart defect and accounts for 10-15% of all congenital heart defects. They occur almost twice as frequently in girls. Atrial septal defects commonly occur in otherwise normal hearts but may be associated with other heart defects including pulmonary stenosis, ventricular septal defect, partial anomalous venous return, patent ductus arteriosus, mitral valve prolapse, and other more complex heart anomalies. The information on this page

Atrioventricular septal defect (AVSD) is a heart defect that involves the valves between the heart's upper and lower chambers and the walls between the chambers. Other terms used to describe this problem include endocardial cushion defect and AV canal defect. A similar but less serious form of atrioventricular septal defect is called primum atrial septal defect or incomplete or partial atrioventricular septal defect. The cause of atrioventricular septal defect is not known. Overall it is quite r