Congenital Heart Disease: Risk Factors for VA/SCD Congenital Heart Disease Incidence of VA Incidence of SCD Higher Risk Characteristics Simple complexity RV dilatation Pulmonary hypertension Moderate complexity Tetralogy of FallotS10.8-1,S10.8-2,S10.8-5,S10.8-6,S10.8 28,S10.8 34,S10.8 36,S10.8 Frequent or complex VA Sustained VT QRS duration 180 ms Inducible sustained VT Atrial tachycardia Decreased LVEF Dilated right ventricle Severe PR Severe PS Aortic stenosis S10.8 27,S10.8 44,S10.8 56 Severe LV hypertrophy Aortic stenosis mean pressure gradient >40 mmHg Ventricular dysfunction Coarctation of aortaS10.8 28,S10.8 29, 2% 2% Aneurysm at repair site Aortic stenosis Systemic hypertension Premature coronary artery disease Atrial fibrillation Wide complex tachycardia Mitral regurgitation Dilated RVOT Severe complexity Transposition of the great arteriesS10.8 27,S10.8 44 S10.8 48,S10.8 Atrial switch Atrial switch 2% 3% 9.5% Mustard repair Arterial switch 2% 1% Prior VSD closure cc-TGA 10% 17% 25% Unexplained syncope Atrial tachycardia Coronary orifice stenosis Systemic ventricular dysfunction Severe tricuspid regurgitation 10% 4% Multiple surgical repairs Coronary anomalies Ventricular dysfunction and/or hypertrophy Fontan repair for univentricular physiology*S10.8 27,S10.8 37, Longer duration of follow-up Ascites Protein-losing enteropathy *Univentricular physiology includes: Tricuspid atresia, Double inlet left ventricle, Mitral atresia, Hypoplastic left heart, Unbalanced AV septal defect. ASD indicates atrial septal defect; cc-TGA, congenitally corrected transposition of the great arteries; LV, left ventricular; LVEF, left ventricular ejection fraction; PR, pulmonary regurgitation; PS, pulmonary stenosis; RV, right ventricular; RVOT, right ventricular outflow tract; SCD, sudden cardiac death; VA, ventricular arrhythmia; VSD, ventricular septal defect; and VT, ventricular tachycardia. CLINICAL STATEMENTS AND GUIDELINES Patients with adult congenital heart disease expe- rience a higher rate of complications and inap- propriate shocks compared with other adult 4. Challenges of ICD implantation in patients with adult congenital heart disease may include ana- tomic complexity, intracardiac shunts, and limited vascular access to the ventricle. 