Schematic diagrams of cardiac anatomy in 2 patients who could not be classified by the modified Lucas classification. Red arrows indicate flow direction. (A) Diagram of patient with cor triatriatum, secundum atrial septal defect (ASD), sinus venosus ASD and partial anomalous pulmonary venous return (PAPVR) (right lower pulmonary vein [RUPV] to right atrium [RA]). The accessory left atrial chamber (AC) that received part of the pulmonary veins was connected to both the left and right atria through the ASD and membranous opening. The true chamber was connected to the right atrium through another ASD. (B) Diagram of patient with cor triatriatum, nearly common atrium, and PAPVR (RUPV and right middle pulmonary vein [RMPV] to RA). The accessory atrial chamber that received part of the pulmonary veins was connected to both left and right atrium through ASD and membranous opening. LLPV, left lower pulmonary vein; LUPV, left upper pulmonary vein; RUPV, right upper pulmonary vein; TC, true left atrial chamber.|@|~(^,^)~|@|Overall survival after repair of cor triatriatum sinister. One early death occurred, and there were no late deaths during a median of 74 months of follow-up. The 15-year overall survival rate was 96.9%.

J Chest Surg 2022;55:151~157 https://doi.org/10.5090/jcs.21.134