The Effect Of Catheter Ablation To The Sizes Of Left Atrium For Patients With Atrial Fibrillation

Objective: Clinical and basic researches have shown that atrial fibrillation(AF)can result in atrial structural remodeling, including atrial enlargement and myocardial fibrosis.The duration of atrial fibrillation was positively related with atrial enlargement.In addition,the atrial enlargement can also lead to cardiac dysfunction,which contributes to the maintenance of AF.Catheter ablation has been demonstrated to be an effective therapy for AF.The present study aimed to investigate the effectiveness of catheter ablation to the sizes of left atrium for patients with atrial fibrillation.Methods:83 patients with drug-refractory symptomatic AF who underwent a first-time ablation in the first affiliated hospital of Dalian medical university, were enrolled in the present study. Cardiac echocardiography was given for these patients of atrial fibrillation in the pre-ablation(1-2 days) and post-ablation 6 months.Results:After a follow-up period of 6 months, 3 cases were lost, a total of 80 patients finished the study. According to the follow-up outcome, the patients were divided into recurrence group(n = 33) and sinus rhythm maintaining group(n = 47).The success rate of paroxysmal atrial fibrillation is 57.4 % after ablation and the success rate of persistent atrial fibrillation is 61.5%. The basic characteristics between two groups were no comparable(P>0.05)(Table 1). Multivariate regression analysis showed that LAVI is an independent predictor of recurrence of atrial fibrillation. The cutoff points were 28.9ml/m2(sensitivity 46%, speci?city 70%). The possibility of recurrence of atrial fibrillation after ablation will increase 15% from theprevious(OR:1.15, 95% confidence interval: 1.06-1.24),the LAVI increased by an average 1ml/㎡. The LA anterior-posterior diameter,LA superior-inferior diameter,LA medial-lateral diameter, LA volume(LAV) and LAV index(LAVI) in the sinus rhythm maintaining group decreased significantly after ablation(38.2±3.6 vs.36.8±4.5,P<0.01; 41.0±4.1 vs. 38.2±4.7, P<0.01; 52.8±6.8 vs. 49.2±6.9, P<0.01; 44.4±12.9vs36.9±13.3, P<0.01; 23.8 ± 6.4 vs. 19.8 ± 6.4, P<0.01, respectively); However, there were no differences in these characteristics between the pre-ablation and post-ablation in the recurrence group. According to the AF type before ablation, the two groups were further divided into the four subgroups: sinus rhythm maintaining group of paroxysmal AF(PAF)(n = 31), recurrence group of PAF(n = 23), sinus rhythm maintaining group of Pe AF(n = 16) and recurrence group of Pe AF(n = 10). The LA anterior-posterior diameter,LA superior-inferior diameter,LA medial-lateral diameter LAV and LAVI decreased significantly after ablation in the sinus rhythm maintaining group of paroxysmal atrial fibrillation(Pa AF)(P<0.05). The LA superior-inferior diameter,LA medial-lateral diameter LAV and LAVI were significantly decreased(P<0.05)after ablation in the sinus rhythm maintaining group of Pe AF, with no change in the LA anterior-posterior diameter(P> 0.05). In contrast, these variabilities did not change after ablation both in the recurrence group of PAF and the recurrence group of Pe AF, there no significant difference between the pre-ablation and postablation(P> 0.05).Conclusion:(1) LAVI is an independent predictor of AF recurrence after catheter ablation.(2) Successful ablation of AF and maintenance of sinus rhythm could decrease the left atrial diameter, LAV and LAVI.(3)Failure to maintain sinus rhythm after ablation could not decrease the LA diameter, LAV and LAVI.