Evaluation Of Left Atrial Function In Patients With Atrial Fibrillation By Echocardiographic And The Risk Of Recurrence After Radiofrequency Ablation

Objective: To evaluate the relationship between pre-operative left atrial function and post-operative recurrence in patients with paroxysmal atrial fibrillation undergoing catheter radiofrequency ablation for the frist time through two-dimensional speckle tracking imaging（2D-STI）of echocardiographic,to explore the predictors of recurrence in post-operative patients with paroxysmal atrial fibrillation and to provide a reference value for patients with atrial fibrillation.Methods:1.Subjects: A total of 75 patients with paroxysmal atrial fibrillation undergoing catheter radiofrequency ablation for the frist time from March2014 to June 2015 were chosen from the second hospital of hebei medical university.2.Methods: All the patients has performed echocardiography before catheter radiofrequency ablation,left ventricular ejection fraction（LVEF）,left ventricular end-diastolic diameter（LVEDD）,left ventricular end-systolic diameter（LVESD）,left atrial dimension（LAD）,peak velocity of early diastole（VE）,peak velocity of late diastole（VA）,E/A,left atrial maximum volume（LAVmax）,left atrial minimum volume（LAVmin）and left atrial preliminary systole volume（LAVP）were measured.Left atrial active ejection fraction（LAAEF）and left atrial passive ejection fraction（LAPEF）were calculated.Left atrial wall strain and strain rate were measured by two-dimensional speckle tracking technology,and the average levels of the mSRs,mSRe,mSRa and mGLS were calculated.After postoperative follow-up of 3 months,patients with recurrence of atrial fibrillation wereincluded in the recurrence group,the others were included in the no recurrence group.Left atrial function strain and strain rate were compared between groups.3.Statistical analysis: Creating a database through the application of SPSS 19.0 software package for statistical analysis.Normal distribution:measurement data were expressed as mean ± standard deviation（x ± s）,the intergroup difference was compared with the independent sample t-test,correlation analys by Pearson correlation coefficient.Non-normal distribution:the intergroup difference was compared with the independent samples nonparametric test,correlation analysis by Spearman correlation coefficient.Analysis of the independent risk factors for recurrence of atrial fibrillation using multivariable logistic regression analysis.P-value <0.05 was considered statistically significan.Results: 1.A total of 75 cases of patients with paroxysmal atrial fibrillation undergoing radiofrequency ablation was collected,after postoperative follow-up of 14 ± 3.5 months on average,12 cases was enrolled in the recurrence group,the recurrence rate was 16%;63 cases was enrolled in the no recurrence group,the success rate was 84%.There was no significant difference in age,gender,hypertension,diabetes mellitus,diabetes mellitus,smoking,family history of atrial fibrillation between groups（P>0.05）;2.There was no significant difference in LVEF,LVEDD,LVESD,LAD,VE,VA and E/A between groups;3.Compared with no recurrence group,the levels of LAVP,LAVmax,LAVmin were significantly increased in the recurrence group（P<0.001）,but LAAEF was significantly reduced（P<0.001）.There was no significant difference in LAPEF between groups（P>0.05）;4.Compared with no recurrence group,the levels of mSRs [（1.26±0.56）vs（1.70±0.43）s^-1],mSRe [-1.63（-2.05^-1.23）vs^-1.90（-2.48^-1.60）s^-1],mSRa [（-1.51±0.67）vs（-2.49±0.88）s^-1] and mGLS [（28.38±11.86）vs（38.77±9.59）s^-1] were significantly reduced in the recurrence group（P<0.05）,and that pump function,conduit functions and reservoir function were significantly reduced;5.mSRs and LAVmax were negatively correlation（r=-0.525;P<0.05）,mSReand LAPEF were positively correlation（r=0.474;P<0.05）,mSRa and LAAEF were positively correlation（r= 0.541;P<0.05）,left atrial strain mGS and LAD were negatively correlation（r =-0.498;P<0.05）and negatively correlated with LAVmax（r=-0.610;P<0.05）;6.Logistic regression analysis revealed that the independent predictor for the recurrence of atrial fibrillation was LAVP and LAAEF.Conclusion:1.Left atrial strain and strain rate can be used to evaluate left atrial function.The peak period of strain rate and its corresponded parameters of left atrial pump function,conduit functions and reservoir function of the volume,ejection fraction have a good correlation.2.Strain rate of preoperative patients with paroxysmal atrial fibrillation is significantly associated with postoperative recurrence.3.The independent predictors for the recurrence of atrial fibrillation are left atrial preliminary systole volume and left atrial active ejection fraction.