Prominent Chiari Network as a Cause of Cyanosis in Infants: A Case Report and Implications for Pediatric Cardiology Practice.

The Chiari network (CN) is an embryological remnant generally regarded as a benign incidental finding. When large and mobile, it may redirect venous blood across atrial communication and provoke cyanosis. We report a 1-month-old infant referred with a presumptive diagnosis of Tetralogy of Fallot whose intermittent desaturation was ultimately attributed to a prominent CN that streamed blood across a sizable atrial septal defect (ASD) in the setting of double outlet right ventricle (DORV). Recognition of this mechanism permitted conservative management until elective repair at 6 months (weight 6 kg). This case adds to the limited number of reports documenting CN-induced positional right-to-left shunting in infants with DORV and underscores how meticulous echocardiography can prevent premature surgery in underweighted neonates.