Echocardiography Evaluation Of Iatrogenic Atrial Septal Defect After Combined Procedure Of Catheter Ablation And Left Atrial Appendage Closure For Atrial Fibrillation

Objective:Using transthoracic echocardiography(TTE)and transesophageal echocardiography(TEE)to investigate the occurrence and related causes of iatrogenic atrial septal defect(iASD)after catheter ablation combined with left atrial appendage closure(LAAC)for atrial fibrillation(AF)and its impact on the right heart system.Methods:We retrospectively analyzed 330 patients that underwent combined procedure of catheter ablation for AF and LAAC at General Hospital of Northern Theater Command from January 2018 to March 2022.There were 179 males and 151 females,with an average age of 65.81±4.35 years.Exclusion criteria: 1.Patients with contraindications for TEE;2.Patients with previous TSP,valvular disease,idiopathic cardiomyopathy,congenital atrial septal defect or other complex congenital heart disease;3.Patients with severe cardiac dysfunction or other systemic diseases;4.Patients with frequent atrial/ventricular premature contraction or other factors that interfere with image quality.These patients underwent TEE at 3 month and TTE at 24 hours,3 and 6 months after operation and were divided into persistent iASD group and spontaneous closure group according to whether there was persistent iASD at 3-months follow-up.Baseline information of all patients was collected,including gender,age,height,weight,BMI,hemoglobin(Hb),serum albumin(ALB),serum cholesterol(TC),history of hypertension/diabetes/pulmonary disease/kidney disease/coronary heart disease/peripheral vascular disease/myocardial infarction /TIA/ stroke/previous history of left atrial appendage thrombosis,CHA2DS2-VASc score,HAS-BLED score,atrial fibrillation type,preoperative anticoagulation,type/size of device,type/size of sheath,number/position of TSP,procedure time of left atrium.Image acquisition data pre-operation and post-operation were collected.Test measurement with TTE:The subjects were asked to rest peacefully for 5-10 min.The left lateral long axis section of the left ventricle beside the sternum was taken to measure the anterior and posterior systolic diameter,diastolic aortic diameter,anterior and posterior right ventricular diameter,diastolic ventricular septal thickness,anterior and posterior left ventricular diameter,and posterior left ventricular wall thickness.Left ventricular ejection fraction,cardiac volume,cardiac output and left ventricular short axis shortening rate were calculated by M-mode echocardiography.The inner diameter of pulmonary artery was measured at the short axis section of the great artery.The blood flow velocity in pulmonary artery during systolic period was measured by continuous Doppler or pulse Doppler.The degree of regurgitation of tricuspid valve and pulmonary valve and the continuity of atrial septum were measured by color Doppler.The systolic right atrium size was measured in the apical four-chamber heart and two-chamber view.The blood flow velocity in the early and late diastolic mitral valve orifice was measured by continuous Doppler or pulse Doppler.The left ventricular diastolic function was determined according to the ratio of E/A.The area and velocity of second and tricuspid valve regurgitation during systolic period were measured and the pulmonary artery pressure was estimated.Simpson method was used to measure left atrial end-diastolic volume and left atrial end-systolic volume,and left atrial ejection fraction was calculated.Tissue Doppler was used to measure the mitral ring velocity,including early peak diastolic velocity e ’and late peak diastolic velocity a’,and the mitral valve E/e ’was used to estimate the left ventricular filling pressure(<8 indicating normal,>14 indicating elevated).Color Doppler was applied to the apical five-chamber view of the heart to observe whether there was regurgitation in the left ventricular outflow tract.Continuous Doppler or pulse Doppler was used to measure the flow velocity in the left ventricular outflow tract and in the aorta during systolic period.TEE was used to assess the LAA at angles of 0°,45°,90° and 135°,and 3-5 cardiac cycles were taken and saved for off-line analysis.The data from TTE and TEE before and after surgery were collected to evaluate the relevant causes of iASD after combined operation of catheter ablation and LAAC,and the influence of the presence of iASD on right heart system was explored.Results:1.Comparison of baseline information and operative data between the two groups:There were no significant differences on gender,age,BMI,smoking history,comorbidities,type of AF,INR,ALB and TC between two groups(P > 0.05).Preoperative left atrial volume was larger in the persistent iASD group(p=0.036).The persistent iASD group has longer procedure time within left atrium(92.1±36.3vs 69.1±17.8 min,p=0.003)and larger size of sheath(4.1±1.2mmvs 3.3±1.2mm,p=0.022).We found that the use of ICE was associated with iASD(p=0.048).In addition,we also observed that the puncture site was relatively low,about 1.85±2.23 cm above the ostium of the inferior vena cava.2.Comparison on Echocardiographic parameters 3 months after operation between the two groups:The persistent iASD group had higher occurrence of postoperative MR(32.3%vs12.8%,p=0.018)and postoperative TR(27.1%vs7.3%,p=0.002).No significant differences were found on LVEF,CO,SV,FS and other echocardiographic indexes(P >0.05).Comparing the right heart parameters of patients in the persistent iASD group before and after operation,there was no significant differences on right heart size,right heart systolic/diastolic function and pulmonary artery pressure(P>0.05).3.Results of Logistic regression analysis:The occurrence of persistent iASD 3 months after surgery(no persistent iASD=0,the occurrence of persistent iASD=1)was taken as the dependent variable,and the factors with statistically significant differences among single factors(LA size before surgery,MR3 months after surgery,TR 3 months after surgery,left atrial operation time,sheath diameter,intraoperative ICE application)were taken as independent variables and assigned.It was included in the Logistic regression model,and the results showed that the larger left atrium before surgery,the greater degree of mitral regurgitation at follow-up,the longer operation time of the left atrium during surgery,the larger diameter of the sheath tube and the intraoperative use of ICE were the risk factors for iASD healing(P <0.05).Conclusions:1.The occurrence of iASD 3 months after combined atrial fibrillation ablation and LAAC was high.2.The size of left atrium,the manipulation time within left atrium,the size of sheath,and the use of ICE during operation was related to the closure of iASD.3.There is a possibility of right heart volume overload caused by The persisting iASD,but no significant changes in right heart function or pulmonary artery systolic blood pressure were observed in the short term.