Clinical Study On Therapy Of Atrial Septal Defect In Adult Patients

Part One:Short-and intermediate-term Electrical and geometric changes after transcatheter closure of atrial septal defect with the Amplatzer Septal OccluderBackground and ObjectAtrial septal defect(ASD) is one of the most common congenital intracardiac deformities.Accounting for 10%of all congenital heart diseases,ASD ranks the third of that in adults.Atrial arrhythmias are well known long-term complications of ASD,presumably due to chronic atrial enlargement and stretch.Although the open surgery can reduce the incidence of the complications such as heart failure and pulmonary hypertension,it fails to decrease the atrial arrhythmic risk(atrial fibrillation or atrial flutter),maybe as a consequence of atriotomic scar.Researches show that percutaneous ASD closure should result in atrial unloading and arrhythmic risk decreasing.According to the previous work, abnormal electric activity taking place in right atrium exists in ASD patients.The incoordination of the electric activity in right atrium mainly presents as the variation of maxium P wave duration and P wave dispersion.These two indices can predict the occurance of atrial arrhythmia among ASD patients.This article is to evaluate the short- or intermediate-term electrical and geometric changes after transcatheter closure of ASD.Materials and methodData includes 30 patients admitted to the department of cardiology of Zhongshan Hospital from September 2007 to September 2008.In addition to the preoperative EKG and echocardiography,personalized occluder selection was based on the position,shape, diameter of the defect and the distance from each edge of the defect determined by cardiac catheter examination.The surface ECG and TTE variations were studied both preoperatively and postoperatively(1,3,6,12 months from the procedure).ECG test included the indices of maxium P wave duration,P wave dispersion,P-R interval,and QRS duration.TTE test include RADlo,RADtr,RVDlo,RVDtr,LAD,LVDd,LVDs,LVEF,and PASP.Results The obvious deflation and normal size recovery of right atrium and ventriculum were observed 1 month and 3 months after the occlusion respectively.The systolic pressure of pulmonary artery reduced significantly 1 month after the therapy.However,LVEF and the size of left atrium and ventricle showed no apparent changes.RBBB was observed in 13 patients preoperatively.Two diminished 1 month after occlusion.Another two diminished 3 months from the procedure.No noticeable changes of maximum P wave duration and P wave dispersion were seen 1 or 3 months from the procedure,whereas the reduction of these two indices 6 month from the procedure had a statistical significance.ConclusionThe transcatheter closure of the secondary ASD reduced the volume load of right heart, which led to obvious atrial and ventricular deflation shortly after occlusion and normal size recovery 3 months after the occlusion.As the indices that predict atrial arrhythmia,the shortening of maximum P wave duration and P wave dispersion were not observed immediately after the therapy despite the reduction of the volume load.However the improvement of these two indices were seen 6 months after the therapy.The transcatheter therapy reversed the high volume load of right heart.The occlusion not only normalized geometric structure,but also improved the abnormal electric activity of right heart.Part Two:Application of transesophageal echocardiography(TEE) in patients with atrial septal defect after transcatheter closure with the Amplatzer Septal OccluderBackground and objectTranscatheter closure of atrial septal defect(TCASD) using amplatzer duct device has been put into practice in China since 1997.The interventional therapy for secondary ASD accepted by most patients has overcome the demerits of open surgery such as soft tissue damage,scar formation,and delayed recovery.However,TCASD may bring complications like detachment of the occluder to pulmonary artery,systemic allergic reaction and peripheral vascular thrombosis.The previous work on animal proved that the occluder implantation would induce thrombosis both on the surface and inside of the occluder. Whereas we have found no report of such phenomenon on the postoperative ASD patients followed up by TEE.This article is to evaluate the value of TEE in the follow-up of the patients after the interventional surgery.Materials and methodData includes 64 patients who went on regular clinical follow-up in our department from January 2008 to January 2009.The follow-up,including physical examination,surface ECG,TTE,was practised 1,3,6,12 months from the procedure.18 patients underwent TEE test 1 month after the occlusion,16 underwent the test 3 months after the therapy,18 did so 6 months from the procedure,and another 12 were tested 1 year after the occlusion.The indices observed by TEE included the fixation of the occluder,the influence on the function of surrounding structures,and the thrombus on the surface of the occluder and in the atrium. We also compared the calibers of each chamber measured by TTE and TEE.ResultsAmong all 64 patients,no thrombus were detected both on the surface of the occluders and in the atrium.The fixation of the occluders were favorable and there was no interference of the surrounding valves.Residual shunt was found in 1 patient under TTE. No residual shunt was detected by TEE.The caliber variation of the chambers measured by TTE and TEE during each period after the surgery was with no statistical significance.ConclusionTEE and TTE showed no significant difference in measuring the chamber caliber of the ASD patient who underwent postoperative follow-up.TEE could not detect fine thrombi on the surface or inside of ASO after the interventional surgery of ASD.