Background: Isolated persistent left superior vena cava (PLSVC), also known as persistent left superior vena cava (SVC) with absent right SVC, affects 0.09-0.13% of the population. Right SVC is presen..
Background: Isolated persistent left superior vena cava (PLSVC), also known as persistent left superior vena cava (SVC) with absent right SVC, affects 0.09-0.13% of the population. Right SVC is present in the majority of people with left SVC. Rarely, the right SVC may be missing. Here, we discuss a rare case of PLSVC found incidentally in a patient with paroxysmal atrial fibrillation (PAF). Case: A 63-year-old female patient with a history of Paroxysmal Atrial flutter (AFL) and atrial fibrillation (AF) on apixaban, HTN, and HLD was brought to the electrophysiology lab for electrophysiology study (EPS) and AF/AFL ablation due to recurrent symptomatic episodes of AF and AFL despite being on antiarrhythmic medications. Pre-ablation CT chest was not performed as the patient’s baseline creatinine was 1.4 mg/dl. Decision‐making: After the placement of venous access sheaths, intracardiac echocardiogram (ICE) was advanced and ICE imaging was performed. No right-sided SVC was identifiable with the inability to visualize superior aspect of interatrial septum and pulmonary veins. Large coronary sinus was noted. Additionally, we were unable to advance the guidewire into the SVC. Due to abnormal cardiac anatomy and the inability to perform a transseptal puncture, AF ablation was not performed. The patient’s repeat creatinine was 1.2 mg/dl and a CT chest was performed which confirmed the absence of right sided SVC and the presence of PLSVC. Patient was discharged on Dofetilide for rhythm management. Conclusion: During the normal cardiac development, the left-sided anterior venous cardinal system vanishes. However, the left SVC persists when the left anterior cardinal vein is unable to close. The left SVC almost always empties into the right atrium via an expanded coronary sinus. Rarely, the persistent left SVC can reach the left atrium directly, which can cause a partial anomalous systemic venous return. Abnormality of the SVC has implications for electrophysiology procedures and ICE/CT and cMRI imaging are helpful in delineating the anatomy.