Left atrial appendage occluder detachment treated with transthoracic ultrasound combined with digital subtraction angiography guided catcher:A case report

BACKGROUND There are very few cases of cardiac occluder detachment,and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after detachment.This case innovatively used ultrasound guidance combined with digital subtraction angiography(DSA)to completely remove the occluder,accumulating some experience.CASE SUMMARY The patient underwent left atrial appendage occlusion surgery in our hospital due to atrial fibrillation.After the surgery,the occluder fell off and became free in the left ventricle,which is very dangerous.We innovatively used ultrasound guidance,combined with DSA,and interventional surgery to successfully capture the free occluder using a catcher,completely remove it,and then re implant a new left atrial appendage occluder.After the surgery,the patient recovered very well.CONCLUSION The size selection of the occluder is slightly conservative,and the shape of the left atrial appendage opening is irregular.

Welding of shape memory alloy to stainless steel for medical occluder

Dissimilar metal joining between NiTi shape memory alloy（SMA） and stainless steel was conducted.A cluster of NiTi SMA wires were first joined with tungsten inert gas（TIG） welding process,then the NiTi SMA TIG weld was welded to a stainless steel pipe with laser spot welding process.The microstructure of the welds was examined with an optical microscope and the elemental distribution in the welds was measured by electron probe microanalysis（EPMA）.The results show that TiC compounds dispersively distribute in the NiTi SMA TIG weld.However,the amount of TiC compounds greatly decreases around the fusion boundary of the laser spot weld between the NiTi SMA and stainless steel.Mutual diffusion between NiTi shape memory alloy and stainless steel happen within a short distance near the fusion boundary,and intermetallic compounds such as Ni3Ti＋（Fe,Ni）Ti appear around the fusion boundary.

Completed atrioventricular block induced by atrial septal defect occluder unfolding:A case report

BACKGROUND An atrial septal defect is a common condition and accounts for 25%of adult congenital heart diseases.Transcatheter occlusion is a widely used technique for the treatment of secondary aperture-type atrial septal defects(ASDs).CASE SUMMARY A 30-year-old female patient was diagnosed with ASD by transthoracic echocardiography(TTE)1 year ago.The electrocardiogram showed a heart rate of 88 beats per minute,normal sinus rhythm,and no change in the ST-T wave.After admission,TTE showed an atrial septal defect with a left-to-right shunt,aortic root short-axis section with an ASD diameter of 8 mm,a parasternal four-chamber section with an ASD diameter of 9 mm,and subxiphoid biatrial section with a diameter of 13 mm.Percutaneous occlusion was proposed.The intraoperative TTE scan showed that the atrial septal defect was oval in shape,was located near the root of the aorta,and had a maximum diameter of 13 mm.A 10-F sheath was placed in the right femoral vein,and a 0.035°hard guidewire was used to establish the transport track between the left pulmonary vein and the inferior vena cava.A shape-memory alloy atrial septal occluder with a waist diameter of 20 mm was placed successfully and located correctly.TTE showed that the double disk unfolded well and that the clamping of the atrial septum was smooth.Immediately after the disc was revealed,electrocardiograph monitoring showed that the ST interval of the inferior leads was prolonged,the P waves and QRS waves were separated,a junctional escape rhythm maintained the heart rate,and the blood pressure began to decrease.After removing the occluder,the elevation in the ST segment returned to normal immediately,and the sinus rhythm returned to average approximately 10 min later.After consulting the patient’s family,we finally decided to withdraw from the operation.CONCLUSION Compression of the small coronary artery,which provides an alternative blood supply to the atrioventricular nodule during the operation,leads to the emergence of a complete atrioventricular block.

Safety and efficacy of amplatzer duct occluder for percutaneous closure of ventricular septal defects with tunnel shape aneurysm: Medium term follow up

Objectives: Different devices including Amplatzer duct occluder has been used for percutaneous closure of ventricular septal defects. This study reports our medium term follow up of perimembranous and muscular ventricular septal defects with tunnel shape aneurysm closure using the Amplatzer duct occluder. Materials and Methods: From May 2006-December 2012, we used Amplatzer duct occluder in seven ventricular septal defect patients here atHamad General Hospital,Doha,Qatar. There were 4 male and 3 female patients with an age range of 4 - 32 years with a median of 8 years and weight range of 16 - 63 kgwith a median of33 kg. In this group, 6 were perimembranous and 1 muscular and all these ventricular septal defects had a tunnel shape aneurysm. Transesophageal echocardiographic diameter ranged from 4 - 8 mmand Qp/Qs was 1 - 1.6. Angiographically, the diameter on the left ventricular side measured 3.5 - 10 mmand on right ventricular side 2.4?- 5 mm. 8/6 mmAmplatzer duct occluder was used to close these ventricular septal defects. Results: There were no major complications and immediately after the procedure there was no residual shunt in any of these patients and all the patients remained in normal sinus rhythm. One patient was expatriate and no further follow up was available. The rest of the 6 patients had 1 - 80 months with a median of 54 months follow up and none of these patients had any residual shunt and all remained in normal sinus rhythm. Two patients developed trivial aortic valve regurgitation immediate post procedure, one remained unchanged and the 2nd has progressed to mild at this latest follow up. Conclusion: Amplatzer duct occluder is feasible and a safe device for percutaneous closure of selective tunnel shape aneurysmal perimembranous and muscular ventricular septal defects.

Safety and Efficacy of Biodegradable Patent Foramen Ovale Occluder in Patients with Migraine:A Clinical Trial

Background:Transcatheter closure of patent foramen ovale(PFO)has been widely accepted as a highly effective way to treat high-risk PFO-related diseases.However,traditional non-degradable occluders made of metal alloys will permanently exist in the body,resulting in thrombosis,valve damage,hemolysis,arrhythmia,or other complications.The biodegradable PFO occluder developed by Shanghai Mallow Medical Instrument Co.,Ltd.,China can be fully absorbed and degrade into nontoxic ingredients,reducing postoperative complications.Objectives:To study the safety and efficacy of biodegradable PFO occluders in treating PFO.Methods:This single-center clinical trial collected 30 patients treated with a biodegradable PFO occluder.The follow-up period lasted 12 months to analyze the echocardiographic characteristics and headache relief through HIT-6 scores.Results:The immediate success rate was 100%,with no intraoperative severe occlusion-related complications.The contrast transcranial Doppler(cTCD)at 12 months showed that all patients’right-to-left shunts(RLS)were grade I or 0 with no serious postoperative complications,indicating the overall success rate was 100%.The biodegradable PFO occluder mostly degraded six months after the occlusion.Conclusion:PFO closure with a Mallow biodegradable occluder is safe and effective and has no severe complications.

Occlusion of atrial septal defect utilizing occluder devise via minimally invasive right chest approach

Objective To evaluate atrial septal defect(ASD) occlusion employing a small right anterior thoracotomy approach. Methods A total of 21 patients with ASD underwent general anesthesia and 2-3 cm incision was made in the fourth right intercostal space.Utilizing transesophageal or transthoracic echocardiography,the occluder was released using a monotube unit. Results All patients were occluded successfully.No patient required open surgery utilizing extracorporeal circulation.There were no major complications and no evidence of residual atrial shunt. Conclusion ASD occlusion via a minimal surgical incision is safe,less invasive,and has excellent outcomes.

Transcatheter Closure of Perimembranous Ventricular Septal Defect Using the Amplatzer Duct Occluder II

Objective:To evaluate the efficacy of Amplatzer duct occluder II(ADO II)in the treatment of perimembranous ventricular septal defect(pmVSD)in children.Methods:Between June 2017 and June 2020,13 patients with pmVSD had attempted transcatheter closure using ADO II,seven of patients were used antegrade approach and six of them were used retrograde approach.Results:There were 8 males and 5 females,age from 1 to 7 years,weight from 10.5 to 31.0 kg,and VSD size from 2.0 to 4.0 mm.Procedure was successful in all cases with the outer diameter of the occluders ranging from 4 to 6 mm.No aortic,tricuspid regurgitation or residual shunt was found in the immediate ultrasound assessment.No arrhythmia was observed in the Holter monitoring 3 days after the intervention.Discharge echocardiography indicated complete shunt closure.No evidence of occluder prolapse,malignant arrhythmia,or intensed valve regurgitation was seen on a median follow-up of 18 months(range,6 to 36 months).Conclusions:Based on our experience,ADO II showed good efficacy in the early and middle stages of pediatric pmVSD closures.

Effectiveness and Safety of Transcatheter Closure of Various Ventricular Septal Defects Using Second-Generation Amplatzer Duct Occluders

Objective:This study was designed to determine the long-term safety and efficacy of using the Amplatzer Duct Occluder II(ADO II)for the closure of various ventricular septal defects(VSDs).Methods:From January 2011 to December 2019,selected VSD patients were treated through transcatheter intervention using ADO II occluders.The closure results and complications from 188 patients,involving 167 perimembranous ventricular septal defects(pmVSDs),9 intracristal VSDs,11 post surgery residual shunts and 1 post closure residual shunt with the mean outlet diameter3.1±0.8 mm under angiography,were enrolled in this study.Results:The success rate was 98.9%for all procedures.During the median 77-month follow-up period,no cases of complete atrioventricular block(cAVB),infective endocarditis or death occurred.One major adverse event(0.5%)was recorded:cerebrovascular accident occurred 1 day after the procedure in one patient who was transferred to the neurology department.The residual shunt rate was 44.6%,which was the most common minor adverse event.The cardiac conduction block rate was 4.3%.Specifically,one pmVSD patient developed intermittent LBBB during the 28-month follow-up.There were 3 patients(1.6%)with new-onset mild tricuspid insufficiency,and the insufficiency degree was stable during follow-up.There was no new-onset aortic insufficiency that occurred.Conclusions:Transcatheter closure of pmVSDs,some intracristal VSDs,some postsurgery or postclosure residual shunts using ADO II occluders were both safe and effective and yielded excellent long-term results in selected patients.

Isolated Major Aortopulmonary Collateral Artery Causing Heart Failure: Transcatheter Occlusion of Mapcas Using Amplatzer Vascular Plugs and Amplatzer Piccolo Occluders

Major aortopulmonary collateral arteries (MAPCAs) are congenital vessels that arise from the aorta or its first-order branches and are distally connected to the pulmonary arterial vasculature, thereby providing pulmonary blood flow. MAPCAs are often associated with cyanotic congenital heart disease with decreased pulmonary blood flow. Isolated MAPCAs are rare in patients without congenital heart disease with structurally normal hearts. Sometimes, isolated congenital MAPCAs can occur without any lung disease. Isolated MAPCAs represent the occurrence of collaterals in the absence of underlying heart disease, which commonly presents as heart failure, recurrent respiratory tract infection, and pulmonary artery hypertension. We report a rare case of congestive heart failure in a 6-year-old patient with dual arterial supply to an otherwise normal right lung, with a normal bronchial tree, and a structurally normal heart. The patient was successfully managed by the closure of collaterals by Amplatzer vascular plugs II (AVPII) and Amplatzer Piccolo Occluders.

TRANSCATHETER CLOSURE OF LARGE SECUNDUM ATRIAL SEPTAL DEFECTS WITH AMPLATZER~ SEPTAL OCCLUDER

Objective To evaluate the safety and feasibility of transcatheter closure of large secundum atrial septal defects(ASDs)with Amplatzer~ septal occluder(ASO).Methods A total of 26 patients(age 16 to 67 years,median 43 years;body weight 52 to 102 kg,median 67 kg)with large ASDs underwent an attempted transcatheter closure using ASO.Large ASD was defined as those with a balloon-stretched diameter of ≥30 mm.Another 81 patients with small-to-moderate ASD during same period who underwent closure served as controls.Results In patients with large ASDs,the ASD dimension means were(22.1±3.2)mm(range from 16 to 30 mm)and(23.8±2.6)mm(range from 18 to 31mm)assessed by transesophageal echocardiography(TEE)and transthoracic echocardiography(TTE),respectively.The mean balloon-stretched diameter of the ASD was(31.9±2.1)mm(range from 30 to 37mm).The size of device was(32.0±1.9)mm(range from 30 to 36mm).The transcatheter procedure was successful in all patients(100%).Seventeen deployments were performed using the conventional left atrium approach,and remaining 9 patients required the right upper pulmonary vein approach.Immediately after deployment,TEE revealed that complete closure rate was 73%.Procedure-related complications were recorded in 3 patients(12%),including device embolization in one patient,pericardial effusion in one patient,and large hematoma at puncture site in one patient.During follow-up,the complete closure rate increased to 88% at 24h after procedure and 100% at 6 months.The procedural success rates,immediate TEE results and TTE results at 24h and 6 months after procedure,were not significantly different between patients with large ASDs and those with small-to-moderate ASDs.Conclusion Transcatheter closure of large ASDs using ASO is technical feasible and relatively safe.Proper care selection and specific technique modification such as the right upper pulmonary vein approach is vital for the implantation success.

Very large aortic pseudoaneurysm repair using a septal occluder

A 63-year-old man,with previous coronary artery bypass surgery presented with infectious aortitis and a large ascending aorta pseudoaneurysm,causing compression of the left internal mammary graft.Percutaneous intervention with stenting of the graft followed by closure of the pseudoaneurysm using an atrial septal defect occluder was successfully carried out.

Clinical Study on Amplatzer Occluder Device to CloseVentricular Septal Defect

Objectives To evaluate the therapeutic effect of transcatheter Amplatzer device on the closure of ventricular septal defect （VSD）. Methods Among 143 patients with VSD, 135 patients with perimembrane VSD and 2 with muscular VSD aged 2.5 -28 years old, were successfully closed with Amplatzer oeeluder device by the pereutaneous guidwire through femoral artery-VSD-femoral vein route under the guidance of fluoroscopy, ventrieulography and transthoracic echocardiography （TIE）. The diameters of the VSDs were 2.3-15.7 （6.90±2.76）mm by left ventriculography. Results The success rate of transcatheter closure of VSD with Amplatzer devices was 96%（137/143）. Minimal residual amount of shunts were found in one patient, although the shunts was decreased one month after the procedure. There were one patient who had respiratory arrest during the procedure, 7 patients（5%）had conduction disturbance, 3 patients had complete left bundle branch block, 2 patients had complete right bundle branch block, 1 patient had Ⅰ degree atrial-ventricular block and 1 patient had Ⅲ degree atr/al-ventricular block during hospitalization. The diameters of the occluder ranged from 4 to 23 （9.13±3.31）mm and were symmetrical in 122 patients and asymmetrical in 15 patients. Conclusions Transcatheter closure of the perimembranous ventrieular septal defect using Amplatzer VSD occluder device is an efficient method for patients with the perimembranous VSD. The operation is simple with a high success rate and a good effect.

The Changes of Left Ventricular Form and Function After Closure of Moderate-to Large-sized Patent Ductus Arteriosus Using Domestic-made Occluder

Objectives To evaluate the changes of the left ventricular form and function after closure of moderate- to large-sized patent ductus arteriosus （PDA） using domestic-made occluder. Methods 22 patients with PDA underwent procedure successfuly using the domestic-made occluder. The mean PDA minimal （pulmonary end） diameter by aortography was 8.01±2.47 mm （range 4 to 15.5mm）. All patients underwent transthoracic echocardiography （TTE） study before the procedure and the following 48 hours, 3 months after procedure. Results All patients had been implanted the domestic-made occluders successfully with no haematolysis, infective endocarditis, recanalization and other complications. At 3 months, mean LVED was decreased to 50.05±6.55 mm, compared to the pre-procedure （55.67 ±8.48 mm）, P 〈 0.01. After 48 hours of the procedure, mean LVEDD and LVESD decreased significantly （156.22± 51.40 mL vs. 121.28±35.73ml, 57.16±32.07 mL vs. 45.88±15.97 mL）, P〈 0.05. At 3 months, LVEDD decreased to 110.93 ±15.08ml, LVSV reached 73.50± 9.19 mL, compared to the pre-procedure, P 〈 0.01. LVESD decreased to 37.43±10.44 mL at 3 months, P〈 0.05. Conclusions Closuring of moderate- to largesized PDA using domestic-made occluder is effective and safe. After procedure, left ventricular form and function improved.

Safety of an improved patent ductus arteriosus occluder for transcatheter closure of perimembranous ventricular septal defects with abnormally attached tricuspid chordae tendineae

BACKGROUND The off-label use of various devices has been reported for the transcatheter closure of perimembranous ventricular septal defects(PmVSD) because of serious complications, such as heart block and tricuspid regurgitation(TR),associated with conventional ventricular septal defect devices. However, whether certain defects such as PmVSD with abnormally attached tricuspid are fit for interventional treatment is still disputable.AIM To explore the feasibility and safety of transcatheter closure of PmVSD with abnormally attached tricuspid chordae tendineae using an improved patent ductus arteriosus(PDA) occluder.METHODS We retrospectively analyzed 20 patients diagnosed with PmVSD with abnormally attached tricuspid chordae tendineae who underwent interventional treatment using an improved PDA occluder at our center from January 2012 to January 2016. Baseline characteristics and procedural and follow-up data were analyzed.RESULTS All 20 patients achieved procedure success. No heart block occurred during the operation. One patient had a transient complete right bundle branch block within48 h post-procedure and reverted to normal rhythm after intravenous injections of dexamethasone for 3 d. For all 20 patients, no residual shunt was observed by transthoracic echocardiography post-procedure. During the average follow-up period of 2.4 years, no severe TR was observed.CONCLUSION Using of the improved PDA occluder for the transcatheter closure of PmVSD with abnormally attached tricuspid chordae tendineae is a safe and promising treatment option. However, long-term follow-up in a large group of patients is still warranted.

Transcatheter Closure of a Right Pulmonary Artery to Left Atrium Fistula Using a Ventricular Septal Defect Occluder

Background:Communication between the right pulmonary artery(RPA)and left atrium(LA)is a rare cause of central cyanosis in pediatric patients.Case presentation:We describe a 3-year-old female patient with an oxygen saturation of 70%at admission.The echocardiogram indicated an abnormal color flow Doppler in the LA and she underwent standard cardiac catheterization.The angiography of pulmonary artery revealed a 7.4 mm×7.6 mm fistula between the RPA and LA and achieved successful closure using ventricular septal defect occlusion.Conclusion:The fistula between pulmonary artery and left atrium is an extremely rare but treatable congenital defect.It should be considered in differential diagnosis of cyanosis in children.

Transcatheter closure of secundum atrial septal defect using an Amplatzer septal occluder

Objective To evaluate the safety and efficacy of the Amplatzer septal occluder for transcatheter closure in patients with secundum atrial septal defect (ASD Ⅱ).Methods Patients with clinically confirmed ASD Ⅱ were recommended for transcatheter closure of ASD Ⅱ. Results 30 ASD Ⅱ patients (20 females) underwent transcatheter closure at a median age of 18.4 years (5-55 years). Both the stretched diameters of ASDs and the sizes of the devices were from 18 to 34?mm (25±7?mm). The successful placement rate was 100%. The rest shunt documented by color Doppler, was immediately after implantation in 40% of patients, in 9.9% after 24 hours, and in 3.3% trace at 3 months. No serious complications were observed. There was improvement in symptoms and in cardiac size. Septal motion abnormalities normalized in all patients after 3 months follow-up.Conclusion The Amplatzer septal occluder is a safe and effective device for transcatheter closure of ASD Ⅱ. Long-term follow-up is still required before widespread clinical use can be recommended.

Reliability of transthoracic echocardiography in estimating the size of Amplatzer septal occluder and guiding percutaneous closure of atrial septal defects

Background In China, transthoracic echocardiography （TTE） is popularly used for pre-intervention examination for atrial septal defect （ASD） and for guiding ASD closure. However, the ability to determine ASD size and the safety and efficacy of l-rE for guiding ASD closure still has not been widely accepted. This study aimed to evaluate the efficacy and safety of l-rE used before, during and after transcatheter ASD closure with Amplatzer septal occluders （ASO）. Methods Sixty-eight subjects （15 men and 53 women; mean age （33.7±17.3） years） were enrolled. TTE was used to measure the diameters and guide transcatheter closure of ASD. The ASD was examined by long-axis view, basal short-axis view, apical four-chamber view and the subcostal view to observe position, diameter and relation with neighbouring structures. The largest diameter was selected as the reference diameter. Patients were divided into 3 groups according to the ASD reference diameter： 22 subjects with ASD diameter 4-14 mm （group A）; 21 subjects with ASD diameter 15-20 mm （group B）; and 25 subjects with ASD diameter 21-33 mm （group C）. Results ASD was occluded successfully in groups A and B. In group C, occlusion failed in 2 cases; 1 case remained with a 3-mm residual shunt sustained until 6-month follow-up. However, at 6-month follow-up, no case of thromboembolism, ASO dislocation or death occurred in the three groups. The diameter of ASD measured by l-rE could accurately predict the ASO size that could successfully occlude the ASD, especially in patients with ASD 〈20 mm. The ASD diameter measured by l-rE correlated well with ASO size （r= 0.925, P〈0.001 ; r=0.976, P〈0.001 ; r=0.929, P〈0.001 respectively）. Conclusions ASD diameter measured by l-rE can accurately estimate the size of the ASO needed for successful closure of ASD. The larger the ASD, the much larger the ASO needed. l-rE is a satisfactory guiding imaging tool for ASD closure.

Transcatheter closure of a giant coronary artery fistula with patent duct occluder

Coronary artery fistula （CAF）, an uncommon form of congenital heart disease, is characterized by abnormal communication between a coronary artery and a cardiac chamber or vessel. This disease is often found incidentally in asymptomatic individuals, and leads to cardiac failure, myocardial ischemia and angina, infective endocarditis, and heart rupture in later life. Both surgical repair and transcatheter closure were effective and safe in the treatment of CAF, but percutaneous management of CAF can obviate median sternotomy and cardiopulmonary bypass, and there may be less morbidity with transcatheter embolization techniques, including the use of occluders or microcoils. We report a successful percutaneous closure of a giant CAF from the left coronary artery to the right ventricle using patent duct occluder.

Low molecular weight heparin microcapsule coated occluder for atrial-septal defects

Background Whether the low molecular weight heparin microcapsule coated occluder is helpful to endothelialization in atrial-septal defect models is uncertain. This study aimed to investigate the best conditions for low molecular weight heparin coated NiTi alloy occluder and provide the evidence of the efficacy and safety of atrial-septal defect occluders in vivo. Methods Low molecular weight heparin microcapsules were investigated using gelatin as microcapsule material. The prepared low molecular weight heparin gelatin particles were subjected to nickel and titanium alloy occluder coating by sodium hyaluronate. A dog model of atrial septal defects was established after treatment with low molecular weight heparin microcapsule coated occluder （n=4） and uncoated occluder （n=4）. Endotheliocytes and fibroblastic cells in occluders were observed. And the rate of endothelialization was detected. Results When the concentration of gelatin was 1%, the diameters of particles were mostly about 100 μm, and the particle size was uniform. The envelope efficiency of low molecular weight heparin microcapsule was about 80%. The endothelialization of occluder in the model was more obvious in the coated group than in the uncoated group （P 〈0.0001）. Conclusions Low molecular weight heparin can be prepared into microcapsules with their particle size in nanometric grade. The antithrombotic properties are kept in the nickel and titanium alloy occluder successfully coated with sodium hyaluronate. The endothelialization after the interventional occlusion in the coated group is obvious, indicating that low molecular weight heparin is helpful to the growth of endothelial cells in the occlude and the healing after the interventional occlusion.

Value of the Ratio of Occluder Versus Atrial Septal Length for Predicting Arrhythmia Occurrence after Transcatheter Closure in Children with Ostium Secundum Atrial Septal Defect

Background：Transcatheter occlusion has been applied to treat ostium secundum atrial septal defect （OS ASD） since 1997.During the clinical practice,several postoperative complications including arrhythmia have been reported.This study aimed to evaluate the value of the ratio of atrial septal occluder （ASO） versus atrial septal length （ASL） for predicting arrhythmia occurrence after transcatheter closure in children with OS ASD.Methods：Six hundred and fifty-one children diagnosed with OS ASD underwent occlusion procedures after completing routine examinations.The onsets and types of arrhythmia both during and after the occlusion procedures were monitored.Treatments were given based on the individual types of arrhythmia.The binary logistic regression analysis and receiver-operating characteristic （ROC） curve were used in the analysis of value of the ratio of ASO/ASL for predicting postoperative arrhythmia occurrence.Results：Transcather occlusions were conducted in 651 children,among whom 7 children had different types and degrees of arrhythmia,with an incidence of 1.1%.The types of arrhythmia included sinus bradycardia,atrial premature beats,bundle branch block,and different degrees of atrioventricular block.Normal electrocardiograph findings were resumed in these 7 patients following active therapies such as corticoids,nutrition,and surgeries.The binary logistic regression and ROC analysis suggested that the ratio of ASO/ASL exhibited an intermediate predictive value for predicting arrhythmia occurrence after occlusion procedures.A cut-offvalue of 0.576 in the ratio provided a sensitivity of 87.5% and a specificity of 76.2% with an area under the ROC curve of 0.791 （95% confidence intervals,0.655-0.926;P 〈 0.05） in predicting arrhythmia occurrence after the closure procedures.Conclusions：The ratio of ASO/ASL might be a useful index for predicting arrhythmia occurrence after closure procedures in children with OS ASD.