The Study Of Left Atrial Strain And Mechanical Dispersion In Predicting The Recurrence Of Patients With Atrial Fibrillation After Radiofrequency Catheter Ablation

Objective: Radiofrequency ablation in the treatment of atrial fibrillation is to eliminate the trigger point of atrial fibrillation and improve the matrix of atrial fibrillation to terminate the arrhythmia and nausea circulation and remodeling.It has become an effective treatment method for patients with ineffective drug therapy,but there is still a certain recurrence rate.Therefore,this study aims to use two-dimensional speckle tracking technology to evaluate the overall longitudinal strain and mechanical dispersion of the left atrium in patients with paroxysmal and persistent atrial fibrillation,in order to evaluate its clinical correlation with recurrence of atrial fibrillation after radiofrequency ablation.Methods: This is a single-center prospective study.A total of 93 patients(28 cases of persistent atrial fibrillation and 65 cases of paroxysmal atrial fibrillation)with a history of atrial fibrillation and confirmed to undergo radiofrequency ablation in our hospital from September 2018 to September 2020 were selected as the subjects of this study.Exclude patients with a history of heart valve disease,congenital heart disease,heart surgery,myocardial infarction,hyperthyroidism,and poor image quality that cannot be analyzed.All patients underwent transthoracic echocardiography and routine measurements one day before surgery.Use two-dimensional speckle tracking technology to evaluate the mechanical function of the left atrium.The total longitudinal strain of the left atrium(GLAS)is defined as the first peak of positive deflection,representing the function of the left atrium reservoir.GLAS is calculated as the average of the overall longitudinal strain of the three apical views(four-chamber,three-chamber,and two-chamber).The mechanical dispersion of the left atrium is defined as the standard deviation of the strain peak time(SD-TPS)of each segment standardized by the R-R interval.With the first recurrence of atrial fibrillation as the end point,the average follow-up time after operation was 10.4±7.6 months(the shortest 3 months,the longest 27 months).The recurrence of atrial fibrillation is defined as an episode of atrial fibrillation with a transcardiogram or dynamic electrocardiogram showing a duration of more than 30 seconds after radiofrequency ablation.The Cox proportional hazards regression model was used to conduct univariate and multivariate analysis of clinical and ultrasound parameters that may be related to the recurrence of atrial fibrillation,and to determine the independent predictors and risk ratios(HR)for recurrence of atrial fibrillation.Establish receiver operating characteristics(ROC curve),determine the area under the curve and the best cut-off point value.Results: After 3-27 months of follow-up,6 patients with persistent atrial fibrillation(recurrence rate 21.4%)and 12 patients with paroxysmal atrial fibrillation(recurrence rate 18.5%)recurred after surgery.Regardless of whether in the persistent atrial fibrillation group or in the paroxysmal atrial fibrillation group,the GLAS of the recurring group was lower than that of the non-recurring group(7.5±2.0vs13.2±3.7,13.6±6.4vs21.9±6.5,P<0.05),and the SD-TPS of the relapsed group was higher than that of the non-relapsed group(8.0±1.7vs5.8±2.2,8.2±2.6vs6.2±2.5,P<0.05).In the Cox proportional hazard analysis,GLAS and SD-TPS were in the persistent atrial fibrillation group(HR: 0.81,CI: 0.68-0.94,P=0.009;HR: 1.24,CI: 1.01-1.47,P=0.018)and paroxysmal atrial fibrillation group(HR: 0.73,CI : 0.60-0.89,P=0.002;HR: 1.86,CI: 1.14-3.03,P=0.013)predictor of recurrence of atrial fibrillation after radiofrequency ablation.Receiver operating curve analysis shows that GLAS is in persistent atrial fibrillation The cut-off points for predicting postoperative recurrence in the group and paroxysmal atrial fibrillation group were 8.72%(AUC=0.902,sensitivity 83.3%,specificity 90.9%,P<0.001)and 15.16%(AUC=0.828,sensitivity 83.3%,specificity83.0%,P<0.001);the cut-off point of SD-TPS for predicting postoperative recurrence in the persistent atrial fibrillation group and paroxysmal atrial fibrillation group was6.27ms(AUC=0.788,sensitivity 83.3%,Specificity 68.2%,P=0.002)and 6.41ms(AUC=0.724,sensitivity 83.3%,specificity 60.4%,P=0.007).Conclusion: Whether in patients with paroxysmal atrial fibrillation or persistent atrial fibrillation,using two-dimensional speckle tracking technology to evaluate the overall longitudinal strain and movement synchronization of the left atrium can help identify patients at high risk of recurrence of atrial fibrillation after radiofrequency ablation,and then guide clinical medication and treatment.