[Early complications following transcatheter occlusion of perimembranous ventricular septal defects in children].

OBJECTIVE: To evaluate the early complications during and after transcatheter closure of perimembranous ventricular septal defects (PMVSDs) in children. METHODS: A total of 223 patients received transcatheter closure of PMVSDs from March 2002 to December 2005 in our hospital were included in this retrospective study. RESULTS: The overall complications rate was 26.9% (60/223). Major complications occurred in 9 patients (4.0%) including III degrees atrioventricular block (AVB) in 2 (0.9%), hemolysis in 3 (1.3%) and surgical interventions in 4 patients (1.8%) because of device malposition (1), mild aortic regurgitation (2) and device embolization (1) and all 4 patients recovered without further complications. The 2 patients with III degrees AVB were completely recovered to normal sinus rhythm after 7 days treatment with temporary pacemaker and corticosteroid. Hemolysis in 3 patients disappeared after corticosteroid treatment. Minor complications occurred in 51 patients (22.8%) including bundle branch block (BBB) in 37 (16.6%), first-degree AVB in 2 (0.9%), second-degree AVB in 1 (0.4%), new-onset mild aortic regurgitation in 5 (2.2%) and new-onset mild to moderate tricuspid regurgitation in 6 patients (2.6%). Except for right bundle branch blocks, other BBBs were treated with albumin and corticosteroid and completely recovered. No treatment was applied for new-onset valve regurgitations. There was no death in all 223 patients. CONCLUSIONS: Early complications post PMVSDs in children are mostly minor with good prognosis and the prognosis for major complications post PMVSDs is good after proper treatment.

[Effects of transcatheter closure in children with congenital coronary artery fistula].

OBJECTIVE: To observe the effects of transcatheter closure method for treating congenital coronary artery fistula (CAF) in children. METHODS: Twenty-three children with CAF received transcatheter closure. Under anesthesia, heart catheterization and selective coronary angiography were performed to show the CAF size and relationship with normal coronary artery. CAF with the narrowest inner diameter < 3 mm (n = 16) were occluded with coil device, and CAF with narrowest inner diameter > 3 mm (n = 7) were closed with Amplatzer duct or VSD occluder. RESULTS: Transcatheter closure was successfully performed in 21 cases and failed in 2 cases (CAF is too tortuous in one case and right CAF outlet near the right coronary artery main stem in another case) and CAF were closed by surgery in these 2 patients. No residual shunt or other complications were observed during the 3 months to 3 years follow up. CONCLUSION: Transcatheter closure was an effective and mini-traumatic method for CAF treatment in children.

[Management of the arrhythmia around the procedure of transcatheter closure of ventricular septal defects in pediatric patients].

OBJECTIVE: To discuss the treatment of arrhythmia occurs in the process of transcatheter closure of perimembranous ventricular septal defects (VSD) in pediatric patients. METHODS: 182 cases (mean age: 6.2 +/- 3.3 years) with membranous VSD underwent transcatheter occlusion procedure. Two different devices were used: the Amplatzer membranous VSD occluder in 81 patients and the domestic-made device in 101 patients. Electrocardiogram of all patients was recorded before and during closure and at one day after the procedure, and Holter monitoring was performed one week after the procedure. RESULTS: Perioperation arrhythmia occurred in thirty-one patients (17%). Second- or third-degree atrioventricular bundle (AVB) was noted during the procedure in four patients. Normal AV conduction recovered spontaneously before the catheters were withdrawn in three cases and another patient underwent surgical repair. In the other twenty-seven patients, arrhythmia was first documented between one day and one week after the procedure. Third-degree AVB was found in three (1.6%) children after the procedure and underwent the temporary pacemaker (TPM) was implanted, two of them recovered to normal sinus rhythm within one week, another patient underwent elective surgery to remove the occluder and repair the defect. Other arrhythmias were: left bundle-branch block (n = 3), right bundle-branch block (n = 12), second-degree AVB (n = 2), sinus tachycardia (n = 6). CONCLUSIONS: In properly selected cases of perimembranous VSD, the transcatheter closure is safe and effective by using appropriate devices. During and after the procedure, closure of VSD can be associated with some kinds of arrhythmia, such as A-V block, more intensive observation and follow-up were therefore needed.

[A follow-up study on transcatheter closure of patent ductus arteriosus with Amplatzer duct occluder in children].

OBJECTIVE: To document the five-year follow-up results of transcatheter Amplatzer duct occluder (ADO) occlusion of patent ductus arteriosus (PDA) in children and to assess the safety and effectiveness of this method for PDA closure. METHODS: A retrospective cohort study was completed in patients with PDA underwent transcatheter closure by the ADO in Guangdong Cardiovascular Institute from April 1998 to December 2003. RESULTS: Transcatheter closure of PDA with ADO was attempted in 250 children patients. The median age was 5.3 years and median weight was 15.1 kg. The PDAs were from 1.8 mm to 11.0 mm (median 4.2 mm) in the narrowest diameter, of which 52 were larger than 5 mm (20.0%). All PDAs were occluded with 4 approximately 14 mm ADO through 6F (n = 205) or 7F (n = 45) sheaths. Devices were successfully implanted in 245 patients (98.0%). The Qp/Qs decreased from 1.90 +/- 0.60 to 1.03 +/- 0.21 (P < 0.05). All shapes of the PDA could be closed. Late complication occurred in five patients, including hemolysis in three patients and the los of the pulse of femoral artery in two patients. Follow-up after device implantation was accomplished in 205 patients (82.0%). The incidence of residual shunt at follow-up periods of 1 d, 1 m, 6 m, 12 m, 24 m, 36 m, 48m and 60 m after device occlusion was 9.2%, 2.8%, 1.2%, 0.8%, 0, 0, 0 and 0, respectively. Five patients (2.0%) required re-intervention to treat residual shunt with or without hemolysis. Event-free rates were 98.0% at one year and five years. CONCLUSION: This long-term follow-up result confirmed the safety and effectiveness of ADO closure of PDAs in children.

[Applying interventional treatment for the atrial septal defect in 165 children under five years of age].

OBJECTIVE: To study the clinical technology of transcatheter closure of secundum atrial septal defects (ASD) with Amplatzer device in younger and lower body weight children. METHODS: The transcatheter closure of ASD using Amplatzer septal occluder (ASO) was performed in 165 children under 5 years of age (75 boys and 90 girls) with secundum ASD from Aug 1998 to May 2004. The age of the cases ranged from 2 to 5 (mean 3.7 +/- 1.1) years. The body weight ranged from 9 to 18 (mean 12.6 +/- 2.3) kg. The ratio of pulmonary circulation quantity to the systemic circulation quantity (Qp/Qs) was 3.2 +/- 1.9. All the patients underwent clinical examination, X-ray, electrocardiography (ECG) and echocardiography (Echo) for diagnosis of secundum ASD. The transthoracic echocardiography (TTE) was used to detect and measure the defect of the patients and even trans-esophageal echocardiography (TEE) had to be used when it was necessary. With Echo and X-ray guidance, the measuring balloon was used in the body and outside the body to determine the balloon-stretch diameters of ASD, and proper occluders were selected accordingly for the patients for interventional treatment of ASD. RESULTS: The devices were implanted successfully in 163 (98.8%) cases. One failure occurred in a case in whom the device moved into the left atrium after release, and the other failure was that the position of the device was uncertain because of temporary unavailability of a special transducer for TEE. Surgical operations were performed for these two cases. The stretch diameter of ASD was from (8 - 30) mm, (mean 18.3 +/- 5.1) mm. The size of device was selected according to the stretch diameter of ASD. The diameter of the occluders selected was from (8 - 30), (mean 18.6 +/- 5) mm in this series. The occlusion procedure was monitored by fluoroscopy and TTE and in 5 cases (3%) by TEE. The diameter of right ventricle was improved within 2 days after occlusion from (mean 16.4 +/- 4.9) mm to (mean 12.6 +/- 3.8) mm, (p < 0.01). One hundred and forty seven cases belonged to the simple secundum ASD(89%). Thirteen cases who were complicated with other cardiac deformity were treated successfully with different interventional procedure. Six cases had multiple openings and three of these cases had tumour-like changes of the atrial septum which were closed completely just by one occluder. In only one case small quantity of residual shunt remains. No other severe complication was found in this group. About 100 cases (60%) had large ASD, so the procedure was more difficult in those cases. CONCLUSION: The clinical effectiveness of treatment of ASD in children under 5 years of age with Amplatzer occluders was satisfactory and therefore this therapeutic procedure is feasible for this age group of patients. Nevertheless, we do not recommend to use the technique for infants and children under 2 years of age. Strict selection of indications and proper size of occluder and good cardiologic and surgical settings are among the basic factors for successful interventional occlusion of ASD in young children.

[Radiofrequency catheter ablation of septum originated tachycardia in children].

OBJECTIVE: The study was undertaken to analyze retrospectively the results of radiofrequency catheter ablation (RFCA) on septum originated tachycardia in children with arrhythmia. The 98 children were all treated with RFCA on septum originated tachycardia in which the ablation sites were located near the bundle of His. METHODS: Fifty female and forty-eight male cases were included in this analysis. They were at the age of 8.1 +/- 2.3 years and their body weight was (28 +/- 9) kg. The arrhythmia they suffered from consisted of atrioventricular nodal reentry tachycardia (AVNRT) (n = 62), atrioventricular reentry tachycardia (AVRT) on septum (n = 25), atria Itachycardia on Koch areas (n = 3) and left ventricular tachycardia (ILVT) on the septum (n = 8). Swartz SRO long sheath was used on the right site ablation. Titration of capacity and degreed time of increase were used in the ablation. RESULTS: Radiofrequency ablation was successful in all cases. Eleven cases had relapse after the procedure. They accepted RFCA again and then the treatment succeeded. One case of AVRT at the posterior septum experienced complete atrioventricular block (AVB) during ablation. Two weeks later this case was implanted with permanent pacemaker. CONCLUSIONS: The septal site is narrow and small in children. Atrioventricular node is tender. If the above facts were neglected, it was very likely to cause AVB, especially in children accepting the procedures of electrophysiologic study an RFCA on the septal site. Attention should be paid to the followings during such procedures: ablation in the sinus rhythm; ablation following the principle, titration of capacity and degreed time of increase; ablation at the right site long sheath; thermo-ablation catheter application and ablation on the two sides of septum in the posterior septum ablation procedure. The end-point of ablation in children should be the elimination of tachycardia and the delta wave, disassociation of VA or passing through bundle of His at pacing in the ventricle, disappearance of jumping conduction or no echo or one echo but without AVNRT after infusion of isoprenaline and stimulation procedure. Avoiding bundle of His injury is important during the procedure of ablation in children.

[Ablation of postoperative "incisional" reentrant atrial tachycardia and flutter in children using the CARTO system].

OBJECTIVE: In children with congenital heart diseases who have undergone surgical interventions, postoperative arrhythmias frequently complicate the clinical course. "Incisional" atrial tachycardia or flutter is one of the most common forms of postoperative arrhythmias in these patients and can lead to significant morbidity and even mortality. The aim of this study was to investigate how to use antiarrhythmic drugs and the CARTO system to treat these cases. METHODS: There were 12 patients with "incisional" atrial tachycardia or flutter complicating surgery for congenital heart diseases in this study (3 patients with correction of tetrology of Fallot, 3 with atrial septal defect repair, 2 with ventricular septal defect repair, 1 with switch, 1 with repair of Ebstein's anomaly, 1 with total anomalous pulmonary venous drainage, and 1 with atrial septal closure with the Amplatzer septal occlusion). Patients whose body weight was less than 10 kg or those who did not wish to accept ablation were treated with antiarrhythmic drugs, including digitoxin, propranolol, metoprolol and cordarone. CARTO system was used to map 6 patients whose body weight was more than 10 kg and who agreed with accepting ablation for atrial tachycardia and flutter. Radio-frequency ablation was performed in these 6 cases including two cases of "incisional" atrial tachycardia and 4 of atrial flutter. RESULTS: (1) The antiarrhythmic drug was successful in 6 patients with "incisional" atrial tachycardia. (2) Six patients including 2 children with "incisional" atrial tachycardia and 4 children with atrial flutter were successfully ablated. But one case of "incisional" atrial tachycardia relapsed after 3 months of ablation. This case, however, was successfully ablated again later. No further relapse was observed during the 2 - 24 months of follow-up. CONCLUSION: Ablation of "incisional" atrial tachycardia and flutter is the first choice to treat the patients whose body weight is more than 10 kg and those who agree with accepting ablation by CARTO system. Drug therapy of "incisional" atrial tachycardia and flutter is palliative and it is the only selection to treat the patients whose body weight is less than 10 kg or those who do not wish to accept ablation procedure.