A 60-year-old woman with drug refractory paroxysmal AF was referred for PVI. Because of a previous failed attempt, the puncture of the interatrial septum was performed under general anesthesia with transesophageal echocardiography (TEE) guidance. IV heparin anticoagulation was given to maintain an activated clotting time of between 250 and 350 s. An irrigated ablation catheter (3.5-mm-tip Navistar Thermocool; Biosense Webster; Diamond Bar, CA) was used for three-dimensional electro-anatomic mapping (Carto XP; Biosense Webster). The catheter was deployed 2 to 4 cm into each PV and slowly pulled back to add separate PV geometries to the left atrium (LA) body. The right inferior PV (RIPV) was the last to be mapped; following the acquisition of a set of points, the catheter could not be maneuvered anymore. Figure 1A shows the position of the catheter in the RIPV. Gentle repetitive tractions were applied, which only produced a downward shift of the heart silhouette on fluoroscopy. The transseptal guiding sheath was advanced to provide additional support and optimize the vector of traction, and catheter irrigation flow was increased and IV nitrates were infused to try to dilate the distal PV, but all these maneuvers failed to free the catheter. TEE showed no pericardial effusion. A cardiothoracic surgical opinion was obtained. Only stronger tractions and rotations eventually allowed us to retrieve the catheter, but unusual resistance was felt during this maneuver. Visual inspection showed a thin, translucent membrane covering the catheter tip, suggesting mechanical disruption of a vein branch (Fig 2A). Figure 1B shows the LA angiogram after catheter removal. The main trunk of the RIPV remained patent with no contrast extravasations, but a tapered narrowing of its superior branch suggesting vascular wall tearing was observed. This superior branch was clearly seen on the preoperative MRI, as shown in Figure 2B, and its diameter was approximately the size of the ablation catheter. Because the patient remained stable, the procedure was resumed and was followed by a successful PVI. Repeat TEE procedures revealed no pericardial effusion. After recovery from general anesthesia, the patient reported continuous mild chest oppression and blood-tinged sputum. ECG, transthoracic echocardiographic, and chest radiographic results were normal, and all symptoms spontaneously resolved within 48 h. The patient was discharged 4 days after the procedure with low-molecular-weight heparin anticoagulation for a week before starting warfarin. A follow-up MRI scan, performed 2 months after the procedure, showed patency of the superior branch of the RIPV (data not shown). The disruption of the vein was thus transient, suggesting stripping of the internal layers of the vessel rather than complete avulsion.