Effect of previous cardiac surgery for structural heart disease and radiofrequency catheter ablation on the mechanism of atrial flutter

Abstract

Objective The present study aimed to analyze the effect of previous cardiac surgery(PCS)for structural heart disease or radiofrequency catheter ablation(ABL)on the mechanism of atrial flutter. Methods This was a prospective, multicenter, and open registry study.Data were collected from the database platform for interventional therapy of arrhythmia from the national center for cardiovascular diseases.Patients who underwent radiofrequency catheter ablation for AFL were consecutively enrolled from 18 hospitals in 10 provinces between January, 2013 and December, 2015, those with incomplete data were excluded.The patients’ baseline clinical data, perioperative data were collected.According to previous history of catheter ablation or cardiac surgery, patients were divided into three groups, control group(n=322), ABL group(n=31)and PCS group(n=48). The composition of different mechanisms of AFL and the influencing factors of the success rate of present catheter ablation for AFL were analyzed. Results Four hundred and one patients who underwent radiofrequency catheter ablation for AFL were enrolled.Left atrium originating AFL, cavotricuspid-isthmus(CTI)dependent AFL and Right atrium non-CTI dependent AFL account for 9.0%, 82.9% and 8.1% respectively.The majority of AFL mechanism still were typical AFL in control group, ABL-non-AF subgroup and PCS group(91.3%, 66.7% and 64.6%), whereas more left atrium originating AFL were found in ABL-AF subgroup(68.4%, P<0.001). There was no significant difference in AFL success rate among the three groups.As for typical AFL, success rate varied among different NYHA classifications(99.3% vs.100% vs.83.3%, P<0.001). For left atrium originating AFL, left atrium diameter was the major influencing factor(100.0% vs.50.0%, P=0.010). Conclusion In patients with PCS or ABL, typical AFL still was the most common mechanism, However, history of PVAI(pulmonary vein antrum isolation)is associated with a higher proportion of left atrium originating AFL.Previous cardiac surgery and ablation made no difference on acute success rate in all types of AFL. Key words: Atrial flutter; History of cardiac operation; Catheter ablation; Rigistry