Fig. 1

a Photograph shows radiofrequency ablation (triangle) in porcine heart. Two thermocouple probes (asterisk) were placed at the same depth parallel to the needle at distances of 5 mm and 10 mm to monitor the local tissue temperature during the procedure. b Photograph shows laser ablation (arrowhead) in porcine heart. Two thermocouple probes (asterisk) were placed at the same depth parallel to the needle at distances of 5 mm and 10 mm to monitor the local tissue temperature during the procedure. c The coagulation necrosis zones of radiofrequency ablation. The long-axis diameter (a) and short-axis diameter (b) are shown. d The coagulation necrosis zones of laser ablation. The center of laser ablation was carbonized more obviously than that of radiofrequency ablation