Predictors of conduit dysfunction and reopera- tion include placement of small diameter conduits; therefore, insertion of conduits with the largest possible diameter should be attempted,S4.3.6-8 antic- ipating that subsequent valve replacement may be via a transcatheter approach. 5. Right ventricle to-PA conduit intervention, which includes surgical replacement or percutaneous stenting and/or transcatheter valve placement, may be reasonable in asymptomatic patients with severe right ventricle to-PA conduit stenosis or regurgitation in the presence of reduced RV systolic function or dilation in the expectation of improvement in hemodynamics, decreased RV size, improved RV stroke volume, and improved RV ejection fraction. Moreover, peak oxygen con- sumption and anaerobic threshold may also im- prove with conduit intervention. 4.4. Complex Lesions 4.4.1. Transposition of the Great Arteries 4.4.1.1. Transposition of the Great Arteries With Atrial Switch Recommendations for d-TGA With Atrial Switch Referenced studies that support recommendations are summarized in Online Data Supplement 45. COR LOE Recommendations Diagnostic I C-EO Ambulatory monitoring for bradycardia or sinus node dysfunction is recommended for adults with d-TGA with atrial switch, especially if treated with beta blockers or other rate-slowing agents. I C-EO Adults with d-TGA with atrial switch repair should undergo annual imaging with either echocardiography or CMR to evaluate for common long-term complications of the atrial switch. 