congenital anomaly of superior vena cava agenesis of the superior vena cava https://www.malacards.org/card/agenesis_of_the_superior_vena_cava MONDO:0020445 agenesis of the SVC SCTID:204464007 absence of the SVC GARD:0019657 UMLS:C0265929 ICD9:747.49 Orphanet:99114 MEDGEN:539590 absence of the superior caval vein Agenesis of the superior vena cava (SVC) is a rare congenital anomaly of the great veins characterized by unilateral or bilateral complete absence of the SVC. Unilateral agenesis is mainly asymptomatic (most of the time diagnosed incidentally) and patients usually have otherwise normal heart structure. Bilateral agenesis, however, is frequently associated with other congenital cardiac anomalies and/or conduction abnormalities (such as tetralogy of Fallot, atrial septal defect) and typically present symptoms of SVC syndrome. absence of the superior vena cava agenesis of the superior caval vein