Pathological findings of the isthmus between the inferior vena cava and tricuspid annulus ablated by radiofrequency application.

Anatomically guided radiofrequency ablation for the treatment of atrial flutter was performed in a 41-year-old man with interstitial pneumonia. He died of respiratory failure 2 months after ablation, and an autopsy was performed. The whole layer of the ablation site showed a transluminal fibrosis.