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. IIa C-LD Assessment for a communication through the interatrial baffle or venous stenosis is reasonable for adults with d-TGA with atrial switch, particularly if transvenous pacemaker/ICD implantation is considered or leads are already present.S4.4.1.1-1 Therapeutic I B-NR GDMT with appropriate attention to the need for anticoagulation is recommended to promptly restore sinus rhythm for adults with d-TGA with atrial switch repair presenting with atrial arrhythmia.S4.4.1.1-2 Synopsis Common problems for patients with d-TGA with atrial switch (Mustard or Senning procedure) include leak across or obstruction of the venous pathways, arrhyth- mias, need for pacemakers/defibrillators, and systolic dysfunction of the systemic ventricle. Although re- ports describing these sequelae abound, data that in- form management decisions are sparse, and many of the most common clinical issues cannot be addressed by data-supported recommendations. Two such issues are medical therapy for RV dysfunction and prevention of SCD. The systematic review report, Medical Therapy for Systemic Right Ventricles: A Systematic Review (Part 1) for the 2018 AHA/ACC Guideline for the Management of Adults With Congenital Heart Disease, has the complete systematic evidence reviewS4.4.1.1-3 for addi- tional data and analyses. The results from the question Are outcomes improved with angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, beta blockers, or aldosterone antagonists alone or in combi- nation in patients with a systemic right ventricle? and the writing committee s review of the totality of the literature demonstrated that medical therapy for sys- tolic ventricular dysfunction remains largely uncertain. Consequently, no recommendations regarding specific medical therapy for systolic dysfunction of the systemic right ventricle can be made. 