A 56-year-old male patient was admitted for catheter ablation of highly symptomatic paroxysmal atrial fibrillation. During the procedure, a rare anatomic variation with an interrupted inferior caval vein (ICV) branching suprarenal into an azygos venous continuation draining into the superior caval vein was detected. Using angiography, a continuation of the ICV leading into the liver, subdividing into 5 smaller branches draining into the right atrium (RA), was displayed. Despite this challenging anatomic variation, successful pulmonary vein isolation (PVI) was performed. A 56-year-old male patient was admitted for catheter ablation of highly symptomatic drug-refractory paroxysmal atrial fibrillation (2 to 3 episodes per week), first diagnosed 48 months before the procedure. Physical examination revealed no anomalous findings, and medical history was unremarkable except for a known 1-vessel coronary artery disease with status post bare metal stent implantation in the left anterior descending artery, normal left ventricular function, and left atrial (LA) diameter of 51 mm. No LA thrombus was detected before the procedure by transesophageal echocardiography. No additional preinterventional imaging was performed. ### Ablation Procedure After written informed consent was obtained, the procedure was performed under conscious sedation using boli of midazolam, fentanyl, and a continuous infusion of propofol (1%). Venous accesses (8F) were achieved via the right femoral vein, the left femoral vein, and the left subclavian vein. Positioning of both deflectable diagnostic catheters (7F, Webster, Biosense Webster, Diamond Bar, Calif) in the coronary sinus from the left subclavian vein and at the His-bundle region via the left femoral vein was unremarkable. ### Transseptal Puncture The guide wire for the first transseptal sheath was introduced via the right femoral vein. The guide wire exhibited an uncommon course and did not enter the RA from inferior; angiography revealed a persistent vena azygos draining into the superior caval vein (Figure 1). An additional angiography from the ICV demonstrated suprarenal …