Changes Of Left Atrial Function After Radiofrequency Ablation Of Frequent Premature Ventricular Contractions In Different Origins

Objective: Frequent premature ventricular contractions can not only affect ventricular function,may also affect atrial function.Catheter ablation of frequent premature ventricular complexes(PVC)improves left ventricular(LV)function and decreases left atrial(LA)volumes in certain patients.However,the study of the influence of LA structure and function before and after successful catheter ablation of PVC in different origins and the trend of the change is not clear.In this study,we attempted to identify the change of LA function after radiofrequency catheter ablation and the influence of PVC originating for that by comparing changes of indexes of left atrial function with before and after radiofrequency catheter ablation in patients with the different sources of frequent ventricular premature,so as to guide the clinical treatment of PVCMethod: The subjects of the study were a total of 68 hospitalized patients with frequent PVC observed on 24-hour Holter monitoring(>10000/24h)and fitting line of radiofrequency ablation surgery at the Second Hospital of Hebei Medical University between December 2014-December 2015.Among them 41 patients with frequent PVC originating in the right ventricle(age: 47 ± 15 years,15 males,PVC burden: 20925±10819)and 27 in the left ventricle(age: 50 ± 17 years,16 males,PVC burden: 21166±10977).All patients before treatment need history taking and preoperative examination.Radiofrequency ablation surgery was performed by the same surgeon,and an unified operation method: the sites of the PVCs were reconstructed using electrical activation mapping and pacing mapping guided by 3-dimensional electroanatomic mapping system(CARTO)and then the ablation was performed based on the location of the ablation is used.The indices of left atrial structure and function were measured by echocardiography before and after radiofrequency ablation surgery at 1 day,2 weeks and 4 weeks.Results: 1 Left atrial structure indicesLeft atrium diameter(LAD): RV PVCs group,the LA showed a slow decreasing trend,the LAD of 2 weeks after operation was the lowest level,and the difference compared with preoperative was statistically significant(P<0.05),4 weeks after operation than 2 weeks was slightly increased but compared with preoperative still has a decreasing trend,but the differences were not statistically significant(P>0.05);LV PVCs group: there was no significant difference in preoperative,1 week,2 weeks,3 weeks,and 4 weeks after radiofrequency ablation surgery(P>0.05);Comparison between groups,although,there was a trend of the LAD after the operation decreased more significantly in the right ventricular origin group than that in the left ventricular origin group,the differences were not statistically significant(P>0.05).2 Heart function indicesLeft atrial ejection fraction(LAEF%): RV PVCs group,the LAEF% of preoperative was significant lower than the healthy controls(63.6±9.3 vs70.3±9.2%,P<0.05);postoperative LAEF increased slowly and upped to the highest point in 4 weeks after surgery,which was significant higher than preoperative(P<0.05),LV PVCs group,preoperative LAEF% was significant lower than the healthy controls(60.9±12.2 vs70.3±9.2%,P<0.05),there was no significant difference in preoperative,1 week,2 weeks,3 weeks,and 4 weeks after radiofrequency ablation surgery(P>0.05);Comparison between groups,although,there was a trend of the LAEF after the operation increased more significantly in the right ventricular origin group than that in the left ventricular origin group,the differences were not statistically significant(P>0.05).3 Left atrial strain indices 3.1 Left atrial strain(S): Difference between the groups was statistically significant(P<0.05),the S after radiofrequency ablation surgery has a tendency to increased gradually,and after radiofrequency ablation in the right ventricular group is higher than that in the left ventricular group(P<0.05).3.2 Left atrial strain rate(SR)3.2.1 Left ventricular systolic(SRs): RV PVCs group,difference between the groups was statistically significant(P<0.05),the SRs after radiofrequency ablation surgery has a tendency to increased gradually,and the SRs of the 4 weeks after operation was the highest;LV PVCs group,1 day after operation was smaller than preoperative(P<0.05);2 weeks after,4 weeks after operation have no difference compared with preoperative;Comparison between groups,although,there was a trend of the SRs after the operation increased more significantly in the right ventricular origin group than that in the left ventricular origin group,the differences were not statistically significant(P>0.05).3.2.2 Left ventricular diastolic early(SRe): there was no significant difference in preoperative,1 day,2 weeks,and 4 weeks after radiofrequency ablation surgery(P>0.05);Comparison between groups,there was no significant difference between the originating in right ventricular group and the originating in left ventricular group;preoperative;after operation,the SRe in the right ventricular origin group is higher than that in the left ventricular origin group(P<0.05).3.2.3 Left atrial systolic(SRa): RV PVCs group,2 weeks,and 4 weeks after radiofrequency ablation surgery was higher than preoperative(P<0.05),but there was no difference between 2 weeks,and 4 weeks after operation;in the left ventricular origin group,there was no significant difference in preoperative,1 week,2 weeks,3 weeks,and 4 weeks after radiofrequency ablation surgery(P>0.05);Comparison between groups,although,there was a trend of the SRa after the operation increased more significantly in the right ventricular origin group than that in the left ventricular origin group,the differences were not statistically significant(P>0.05).Conclusions:1 The LAD of 2 weeks after operation was significant smaller than preoperative in the right ventricular origin group.2 The LAD there was no difference in 4 weeks after operation in the left ventricular origin group.3 In the right ventricular origin group,the LAEF was significant lower than healthy people,and significant improved in 4 weeks after operation.Meanwhile,the S and SR were slowly increased in 1 day to 4 weeks after operation.4 In the left ventricular origin group,the LAEF was significant lower than healthy people,and there was no significant improved after operation.However,the S was slowly increased in 1 day to 4 weeks after operation.5 The LA function improved more significantly in the right ventricular origin group than that in the left ventricular origin group after radiofrequency ablation surgery.