[Comparison of ablation of left-sided accessory pathway by atrial septal and retrograde arterial approach]. 
Objective: To compare the advantages and disadvantages of radiofrequency ablation of left-sided accessory pathways by via atrial septal approach with retrograde through aortic approach.  Methods: A total of 184 patients of left-side accessory pathways were treated in Taizhou People's Hospital and the Subei People's Hospital from March 2012 to August 2015.A total of 103 cases were treated by aortic retrograde approach as through arterial group, 81 cases were treated by punctured atrial septal to left atrial for mapping and ablation as through atrial septal group. Comparison of ablation procedure time, total and pathways of different parts(subgroup) at instant success and relapse rates, safety (serious complications), and statistics other complications in operation and postoperative.  Results: Through arterial group and through atrial septal group were no significant difference (P>0.05) in the ablation procedure time((25±18 ) vs (22±15)min ), instant success(98.1% vs 97.5%) and relapse rates(1.0% vs 1.2%), security(1 vs 0 case).  There was no statistical difference in septal part subgroups (all P>0.05) in the ablation procedure time((22±18)vs (25±19)min), instant success(91.7% vs 89.9 %) and relapse rates(0 vs 11.1%); posterior wall subgroup had no statistical difference in the ablation procedure time((18±15)vs (16±12)min), instant success(100% vs 100 %) and relapse rates(0 vs 0)(all P>0.05); side wall subgroup had no statistical difference in the ablation procedure time((29±20)vs (21±18) min), instant success (98.3% vs 98.1%)and relapse rates(1.7% vs 0%)(all P>0.05).  Conclusion: Ablation of left-sided accessory pathways by transseptal approach and transaortic approach has no statistical difference in the procedure time, instant success and relapse rates, security. In a particular case, there is a certain complementarity between the two methods.