Pulmonary vein isolation in a case of common drainage of a persistent left superior caval vein and the left-sided pulmonary veins into the left atrium

Preprocedural imaging before catheter ablation of atrial fibrillation is often limited. We present a case of a 67-year-old female with unsuspected anatomy relevant to procedure planning. Routine computed tomography revealed an undetected persistent left-sided superior caval vein (LpSVC). All left-sided pulmonary veins drained with the LpSVC by way of a common vessel at the roof of the left atrium (LA). This common vein exhibited low-amplitude signals connected to the LA beyond 25 mm. Both right-sided caval veins and the coronary sinus drained to the right atrium. We struggled to keep the ablation lesions distant from the common vein to avoid an increase of the left-to-right shunt by unintended narrowing of this vessel. The encircling ablation lines around the right-sided pulmonary veins and the common vein were close together so an additional roof line was done. In summary, imaging definitively helped to prepare the ablation procedure and to avoid complications.