Atresia: Absence of a normal opening, or failure of a structure to be tubular. Atresia can affect many structures in the body. For example, esophageal atresia is a birth defect in which part of the esophagus is not hollow, and with anal atresia, there is no hole at the bottom end of the intestine.
- Atresia, anal
Atresia, anal: Congenital absence of an opening at the bottom end of the intestinal tract. Also called imperforate anus. Occurs in about 1 in 5,000 births. It is corrected by surgery. Atresia refers to the absence of a normal opening.
- Atresia, aortic
Atresia, aortic: Congenital absence of the normal valvular opening from the left ventricle of the heart into the aorta. “Atresia” here refers to the absence of a normal opening.
- Atresia, biliary
Atresia, biliary: Congenital absence or closure of the major bile ducts, the ducts that drain bile from the liver. Biliary atresia results in a progressive inflammatory process which may lead to cirrhosis of the liver. The infant looks normal at birth but develops jaundice after the age of 2 to 3 weeks with yellowing of […]
Atrial: Pertaining to the atria, the upper chambers of the heart, as in atrial fibrillation and atrial septal defect.
- Atrial flutter
Atrial flutter: Well-organized but overly rapid contractions of the atrium of the heart (usually at a rate of 250-350 contractions per minute). Flutter refers to a rapid vibration or pulsation. The difference between flutter and fibrillation is that flutter is well organized while fibrillation is not. Atrial flutter is a serious and potentially unstable rhythm […]