Cardiac ablation is a procedure for treating atrial fibrillation. Ablation involves the removal of tissue at the source of the condition. Catheter ablation is the least invasive type of ablation. This involves a doctor inserting a thin tube into your blood vessel and applying heat, cold, or radio energy to the tissue that is triggering the atrial fibrillation. Surgical ablation involves surgically entering the chest cavity and manually creating scar tissue to treat the source of the arrhythmia.