The vast majority of patients with CCTGA have one or more of the following associated defects (1, 2): VSD (> 60%) Pulmonic stenosis (40%) Ebstein anomaly or other dysplasia of the left sided tricuspid valve (90%) Congenital or acquired AV block (progressive in 2% per year, 10 to 15% by adolescents and up to 30% in adults) Malposition with mesocardia or dextrocardia (20%) Progressive dysfunction of the systemic right ventricle (50% by 30 years of age) Pathophysiology references 1.