Pulmonary vein isolation is a common procedure used in the treatment of atrial fibrillation, a type of irregular heart rhythm. During this procedure, a doctor will use various techniques to isolate and block abnormal electrical signals coming from the pulmonary veins, which are often the source of the irregular heartbeat. This can help restore normal heart rhythm and reduce symptoms associated with atrial fibrillation. Pulmonary vein isolation can be done using catheter ablation techniques, such as radiofrequency energy or cryoablation, to create scar tissue around the pulmonary veins and prevent abnormal electrical signals from causing the irregular heartbeat.