Ilbawi procedure (operation)		An operation for congenitally corrected transposition of the great arteries with VSD and PS, wherein a communication is established between the LV and the aorta via the VSD using a baffle within the RV. The RV is connected to the pulmonary artery using a valved conduit. An atrial switch procedure is done. The left ventricle then supports the systemic circulation. (Ilbawi MN et al. An alternative approach to the surgical management of physiologically corrected transposition with ventricular septal defect and pulmonary stenosis or atresia. J Thorac Cardiovasc Surg 1990;100:410-415.)
infracristal		Located below the crista ventricularis in the RV outflow tract. see crista ventricularis.
infundibular, infundibulum		(Pertaining to) a ventricular-great arterial connecting segment. Normally sub-pulmonary, but can be sub-aortic, and may be bilateral or absent. Bilateral infundibulum may be seen in patients with TGA/VSD/PS, DORV with VSD/PS, and anatomically corrected malposition. Also called conus.
inlet VSD		see ventricular septal defect.
interrupted aortic arch		see aortic arch anomaly.
interrupted inferior vena cava		The inferior vena cava is interrupted below the hepatic veins with subsequent systemic venous drainage via the azygos vein to the superior vena cava. The hepatic veins enter the right atrium directly. This anomaly is frequently associated with complex congenital heart disease, particularly left-isomerism.
ISACCD		International Society for Adult Congenital Cardiac Disease.
isolation of arch vessels		see aortic arch anomalies.
isomerism		Paired, mirror image sets of normally single or non-identical organ systems (atria, lungs, and viscera), often associated with other abnormalities.
right isomerism		syn. asplenia syndrome. Congenital syndrome consisting of paired morphologically right structures: absence of spleen, bilateral right bronchi, bilateral tri-lobed (right) lungs, two morphologic right atria, and multiple anomalies of systemic and pulmonary venous connections and other complex cardiac and non-cardiac anomalies.
left isomerism		syn. polysplenia syndrome. A congenital syndrome consisting of paired, morphologically left structures: multiple bilateral spleens, bilateral left bronchi, bilateral bilobed (left) lungs, midline liver, two morphologic left atria, and complex congenital heart disease and other associated non-cardiac malformations.