aberrant innominate artery		A rare abnormality associated with right aortic arch wherein the sequence of arteries arising from the aortic arch is: right carotid artery, right subclavian artery, then (left) innominate artery. The latter passes behind the esophagus. This is in contrast to the general rule that the first arch artery gives rise to the carotid artery contralateral to the side of the aortic arch (i.e.: right carotid artery in left aortic arch and left carotid artery in right aortic arch). syn. retro-esophageal innominate artery.
aberrant subclavian artery		The right subclavian artery arises from the aorta distal to the left subclavian artery. Left aortic arch with (retroesophageal) aberrant right subclavian artery is the most common aortic arch anomaly, first described 1735 by Hunauld, and occurring in 0.5% of the general population.
absent pulmonary valve syndrome		Pulmonary valvular tissue is absent, resulting in pulmonary regurgitation. This rare anomaly uncommonly may be isolated; or it may be associated with ventricular septal defect, obstructed pulmonary valve annulus and massive dilation and distortion of the pulmonary arteries. Absent pulmonary valve may also occur in association with other simple or complex congenital heart lesions.
ACHD		Adult Congenital Heart Disease
Alagille syndrome		see arteriohepatic dysplasia
ALCAPA		Anomalous left coronary artery arising from the pulmonary artery. see Bland-White-Garland syndrome.
ambiguus		With reference to cardiac situs, neither right- nor left-sided (indeterminate). see situs.
Amplatzer device		A self-centering device delivered percutaneously by catheter for closure of an atrial septal defect, a patent foramen ovale or a patent ductus arteriosus.
anomalous pulmonary venous connection		Pulmonary venous return to the right heart, which may be total or partial.
total anomalous pulmonary venous connection (TAPVC)		All pulmonary veins connect to the right side of the heart, either directly or via venous tributaries. The connection may be supradiaphragmatic, usually via a vertical vein to the innominate vein or the SVC. The connection may also be infradiaphragmatic via a descending vein to the portal vein, the IVC or one of its tributaries. Pulmonary venous obstruction is common in supradiaphragmatic connection, and almost universal in infradiaphragmatic connection.
partial anomalous pulmonary venous connection (PAPVC)		One or more but not all the pulmonary veins connect to the right atrium directly, or via a vena cava. This anomaly is frequently associated with sinus venosus atrial septal defect. see also scimitar syndrome.
aortic arch anomalies		Abnormalities of the aortic arch and its branching. Note that left or right aortic arch is defined by the mainstem bronchus that is crossed by the descending thoracic aorta and does not refer to the side of the midline on which the aorta descends. In left aortic arch (normal anatomic arrangement) the descending thoracic aorta crosses over the left mainstem bronchus; the innominate artery branching into the right carotid and right subclavian artery arises first, the left carotid artery second and the left subclavian artery third. Usually, the first aortic arch vessel gives rise to the carotid artery that is opposite to the side of the aortic arch (i.e. the right carotid artery in left aortic arch and the left carotid artery in right aortic arch). The most important anomalies are:
abnormal left aortic arch		Left aortic arch with minor branching anomalies; Left aortic arch with retroesophageal right subclavian artery.
right aortic arch		In right aortic arch the descending thoracic aorta crosses the right mainstem bronchus. It is often associated with tetralogy of Fallot, pulmonary atresia, truncus arteriosus and other cono-truncal anomalies. Types of right aortic arch branching: Mirror image branching (left innominate artery, right carotid artery, right subclavian artery). Retroesophageal left (aberrant) subclavian artery with a normal calibre. Sequence of branching: left carotid artery, right carotid artery, right subclavian artery, then left subclavian artery. Retroesophageal diverticulum of Kommerell. see diverticulum of Kommerell. Right aortic arch with left descending aorta i.e. retroesophageal segment of right aortic arch. The descending aortic arch crosses the midline toward the left by a retroesophageal route. Isolation of contralateral arch vessels: an aortic arch vessel arises from the pulmonary artery via the ductus arteriosus without connection to the aorta. This anomaly is very uncommon. Isolation of the left subclavian artery is the most common form.
cervical aortic arch		The arch is located above the level of the clavicle.
double aortic arch		Both right and left aortic arches are present, i.e. the ascending aorta splits into two limbs encircling the trachea and esophagus; the two limbs join to form a single descending aorta. There are several forms such as widely open right and left arches or hypoplasia/atresia of one arch (usually the left). This anomaly is commonly associated with patent ductus arteriosus. Double aortic arch creates a vascular ring around the trachea and the esophagus. see also vascular ring
persistent 5th aortic arch		Double-lumen aortic arch with both lumina on the same side of the trachea. Degree of lumen patency varies from full patency of both lumina to complete atresia of one of them.
interrupted aortic arch		Complete discontinuation between the ascending and descending thoracic aorta. Type A: Interruption distal to the subclavian artery that is ipsilateral to the second carotid artery. Type B: Interruption between second carotid artery and ipsilateral subclavian artery. Interruption between carotid arteries.
aortic-left ventricular defect (tunnel)		Vascular connection between the aorta and the left ventricle resulting in left ventricular volume overload due to regurgitation from the aorta via the tunnel to the left ventricle.
aortic override		see tetralogy of Fallot.
aortic valve-sparing ascending aortic replacement		see David operation.
aorto-pulmonary collateral		Abnormal arterial vessel arising from the aorta, providing blood supply to the pulmonary arteries. May be single or multiple, and small or large (see also MAPCA). May be associated with tetralogy of Fallot, pulmonary atresia or other complex cyanotic congenital heart disease.
aorto-pulmonary septal defect		see aorto-pulmonary window.
aorto-pulmonary window		A congenital connection between the ascending aorta and main pulmonary artery, which may be contiguous with the semi-lunar valves, or, less often, separated from them. Simulates the physiology of a large PDA, but requires a more demanding repair. syn. aorto-pulmonary septal defect.
arterial switch operation		see Jatene procedure.
arteriohepatic dysplasia		An autosomal dominant multi-system syndrome consisting of intrahepatic cholestasis, characteristic facies, butterfly-like vertebral anomalies and varying degrees of peripheral pulmonary artery stenoses or diffuse hypoplasia of the pulmonary artery and its branches. Associated with microdeletion in chromosome 20p. syn. Alagille syndrome.
asplenia syndrome		see isomerism/ right isomerism.
atresia, atretic		Imperforate, used with reference to an orifice, valve, or vessel.
atrial septal defect (ASD)		an inter-atrial communication, classified according to its location relative to the oval fossa (fossa ovalis):
coronary sinus ASD		Inferior and anterior location at the anticipated site of the orifice of the coronary sinus. May be part of a complex anomaly including absence of the coronary sinus and a persistent left superior vena cava.
ostium primum ASD		Part of the spectrum of atrio-ventricular septal defect (AVSD). Located anterior and inferior to the oval fossa such that there is no atrial septal tissue between the lower edge of the defect and the atrioventricular valves that are located on the same plane; almost always associated with a "cleft" in the "anterior mitral leaflet". This cleft is actually the separation between the left-sided portions of the primitive antero-superior and postero-inferior bridging leaflets. see also AVSD.
ostium secun­dum ASD		Located at the level of the oval fossa.
sinus venosus ASD		see sinus venosus defect
atrial switch procedure		A procedure to redirect venous return to the contralateral ventricle. When used in complete transposition of the great arteries (either the Mustard or the Senning procedure) this accomplishes physiologic correction of the circulation, while leaving the right ventricle to support the systemic circulation. In patients with l-transposition of the great arteries and in patients who have had a previous Mustard or Senning procedure, it is used as part of a "double switch procedure" which results in anatomic correction of the circulation, with the left ventricle supporting the systemic circulation. see also double switch procedure.
atrio-ventricular concordance		see concordant atrio-ventricular connections.
atrio-ventricular discordance		see discordant atrio-ventricular connections.
atrio-ventricular septal defect (AVSD)		A group of anomalies resulting from a deficiency of the atrio-ventricular septum which have in common: 1) a common atrio-ventricular junction with a common fibrous ring, and a unique, 5-leaflet, atrio-ventricular valve; 2) unwedging of the aorta from its usual position deeply wedged between the mitral and tricuspid valves; 3) a narrowed subaortic outflow tract; 4) disproportion between the inlet and outlet portions of the ventricular septum. Echocardiographic recognition is aided by the observation that "left" and "right" A-V valves are located in the same anatomic plane. Included in this group of conditions are anomalies previously known as (and often still described as) ostium primum ASD (partial AVSD), "cleft" anterior mitral and/or septal tricuspid valve leaflet, inlet VSD, and complete AVSD ("complete A-V canal defect"). An older, obsolete, term describing such a defect is "endocardial cushion defect". see also endocardial cushion defect.
atrio-ventricular septum		The atrio-ventricular septum separates the left ventricular inlet from the right atrium. It has two parts: a muscular portion which exists because the attachment of the septal leaflet of the tricuspid valve is more towards the apex of the ventricle than the corresponding attachment of the mitral valve, and a fibrous portion superior to the attachment of the septal leaflet of the tricuspid valve. This latter portion separates the right atrium from the sub-aortic left ventricular outflow tract. see also Gerbode defect.
atrio-ventricular valve (A-V valve)		A valve guarding the inlet to a ventricle. A-V valves correspond with their respective ventricles, the tricuspid valve always associated with the right ventricle, and the mitral valve with the left ventricle. However, in the setting of an atrio-ventricular septal defect, there is neither a true mitral nor a true tricuspid valve. Rather, in severe forms there is a single atrio-ventricular orifice, guarded by a 5-leaflet A-V valve. The "left A-V valve" comprises the left lateral leaflet and the left portions of the superior (anterior) and inferior (posterior) bridging leaflets, while the "right A-V valve" comprises the right inferior leaflet, the right antero-superior leaflet, and the right portions of the superior and inferior bridging leaflets.
cleft A-V valve		A defect often involving the left A-V valve in AVSD formed by the conjunction of the superior and inferior bridging leaflets. A cleft may also be seen in the septal tricuspid leaflet. A similar but morphogenetically distinct entity may involve the anterior or rarely posterior leaflet of the mitral valve in otherwise normal hearts.
common A-V valve		Describes a 5-leaflet A-V valve in complete AVSD that is related to both ventricles.
overriding A-V valve		Describes an A-V valve that empties into both ventricles. It overrides the interventricular septum above a VSD.
straddling A-V valve		Describes an A-V valve with anomalous insertion of tendinous cords or papillary muscles into the contralateral ventricle (VSD required).
autograft		Tissue or organ transplanted to a new site within the same individual.
A-V septal defect (AVSD)		see atrio-ventricular septal defect (AVSD).
A-V valve		see atrio-ventricular valve.
azygos continuation of the inferior vena cava		An anomaly of systemic venous connections wherein the inferior vena cava is interrupted distal to its passage through the liver, and IVC flow reaches the right atrium through an enlarged azygos vein connecting the IVC to the superior vena cava. Usually, only hepatic venous flow reaches the right atrium from below. see also isomerism.