Persistent left superior vena cava (SVC) without the right SVC is very
rare and occurs in 0.07%–0.13% of patients with congenital heart
defects. An enlarged coronary sinus detected during cardiac examination
in the prenatal period is the first finding that raises suspicion for
this anomaly. In this report, a patient was presented who was referred
with the prediagnosis of cor triatriatum sinister in the antenatal
period and diagnosed with isolated persistent left SVC.