Table 1:

Complexity of adult congenital heart disease

Simple CHD	Moderate CHD	Severely Complex CHD
Native disease ○Isolated congenital aortic valve disease ○Isolated congenital MV disease ○Small ASD ○Isolated small VSD ○Mild PS ○Small PDA	Aorto-left ventricular fistulas Anomalous pulmonary venous drainage AVSD (partial or complete) CoA Ebstein anomaly Infundibular RVOTO of significance Ostium primum ASD	Conduits Cyanotic CHD (all forms) Double-outlet ventricle Eisenmenger syndrome Fontan procedure Mitral atresia Single ventricle Pulmonary atresia (all forms) Transposition of the great arteries
Repaired conditions (without residua) ○Ligated or occluded PDA ○Repaired VSD ○Repaired secundum or sinus venosus ○ASD	PDA, not closed Pulmonary valve regurgitation (moderate to severe) Pulmonary valve stenosis (moderate to severe) Sinus of Valsalva fistula or aneurysm Sinus venosus ASD Subvalvular AS or supra-AS Tetralogy of Fallot VSD with absent valves, AI, CoA, mitral disease, RVOTO, straddling TV or MV, sub-AS	Tricuspid atresia Truncus arteriosus, hemitruncus Abnormalities of atrioventricular or ventriculoarterial connection NOS (ie, crisscross heart, isomerism, heterotaxy, ventricular inversion)

Abbreviations: AI, aortic insufficiency; AS, aortic stenosis; ASD, atrial septal defect; AVSD, atrioventricular septal defect; CoA, coarctation of the aorta; MV, mitral valve; NOS, not otherwise specified; PDA, patent ductus arteriosus; PS, pulmonic stenosis; RVOTO, right ventricular outflow tract obstruction; TV, tricuspid valve; VSD, ventricular septal defect.

Modified from Connelly MS, Webb GD, Somerville J, et al. Canadian consensus conference on adult congenital heart disease, 1996. Can J Cardiol 1998;14:395–452; with permission.