Adult Congenital Heart Disease Recommendations for Adult Congenital Heart Disease References that support the recommendations are summarized in Online Data Supplement 54. COR LOE Recommendations I B-NR Adult patients with repaired complex congenital heart disease presenting with frequent, complex, or sustained VA, or unexplained syncope should undergo evaluation for potential residual anatomic or coronary abnormalities.S10.8-1 S10.8-6 I B-NR In patients with adult congenital heart disease and complex or sustained VA in the presence of important residual hemodynamic lesions, treatment of hemodynamic abnormalities with catheter or surgical intervention as feasible is indicated prior to consideration of ablation or an ICD.S10.8-3,S10.8-7 S10.8-12 I B-NR In patients with adult congenital heart disease and hemodynamically unstable VT, an ICD is recommended after evaluation and appropriate treatment for residual lesions/ ventricular dysfunction if meaningful survival of greater than 1 year is expected.S10.8-13 S10.8-17 CLINICAL STATEMENTS AND GUIDELINES I B-NR In patients with adult congenital heart disease with SCA due to VT or VF in the absence of reversible causes, an ICD is recommended if meaningful survival of greater than 1 year is expected.S10.8-13 S10.8-17 IIa B-NR In adults with repaired tetralogy of Fallot physiology with high-risk characteristics and frequent VA, an electrophysiological study can be useful to evaluate the risk of IIa B-NR In adults with repaired tetralogy of Fallot physiology and inducible VT/VF or spontaneous sustained VT, implantation of an ICD is reasonable if meaningful survival greater than IIa B-NR In patients with adult congenital heart disease with recurrent sustained monomorphic VT or recurrent ICD shocks for VT, catheter ablation can be effective.S10.8-21 S10.8-25 IIa B-NR In adults with repaired severe complexity adult congenital heart disease and frequent or complex VA, a beta blocker can be beneficial to reduce the risk of SCA.S10.8-26 IIa B-NR In patients with repaired moderate or severe complexity adult congenital heart disease with unexplained syncope and at least moderate ventricular dysfunction or marked hypertrophy, either ICD implantation or an electrophysiological study with ICD implantation for inducible sustained VA is reasonable if meaningful survival of greater than 1 year is IIb B-NR In patients with adult congenital heart disease and severe ventricular dysfunction (LVEF <35%) and symptoms of heart failure despite GDMT or additional risk factors, ICD implantation may be considered if meaningful survival of greater than 1 year is III: Harm B-NR In patients with adult congenital heart disease who have asymptomatic VA, prophylactic antiarrhythmic therapy with class Ic medications (ie, flecainide, propafenone) or amiodarone is potentially Synopsis Tetralogy of Fallot (TOF) is defined as, congenital heart disease with RVOT obstruction and ventricular septal defect, often requiring right ventricle to pulmonary artery conduit placement or pulmonary valve replace- ment; includes TOF and double-outlet right ventricle. 