Histopathologic effects of endocardial and epicardial percutaneous radiofrequency catheter ablation in dilated nonischemic cardiomyopathy.

We report the histological evaluation of both endocardial and epicardial radiofrequency (RF) ablation lesions in the explanted heart of a patient presenting with nonischemic dilated cardiomyopathy complicated by recurrent electrical storms. In this case, chronic RF lesions were almost transmural at the endocardial side, while remaining only superficial at the epicardial aspect, possibly because of the insulating interposed epicardial fat layer.