Congenital Heart Disease Is Involved In Basic And Clinical Research Of The Treatment On Prevention Of Complications

Section OneIn vitro effect of biologically active coating on biocompatibilityof Nitinol slices designed for the closure of ASDObjective To assess the effects of bioactive coatings on biocompatibilityof Nitinol slices designed for the closure of atrial septal defects (ASD) invitro.Methods We studied the biocompatibility of Nitinol slices in vitro by thetests of hemolysis and cyto-compatibility: 1. The hemolysis test included6 groups: control, uncoating, chitosan, chitosan/fibronectin,chitosan/heparin and chitosan/r-hirudin. Bioactive molecules includingheparin, r-hirudin, and fibronectin, were covalently immobilized onto thesurface of Nitinol slices in differential concentration respectively. Activemolecular groups were divided to low-, middle-, and high-dose groups.The hemocompatibility of biomaterials was evaluated in vitro in adynamic model with whole human blood by the hemolysis test andanticoagulant activity such as partial thrombin time (APTT), prothrombintime (PT), thrombin time (TT), Fibrinogen (FIB) and D-Dimer (DD) weremeasured as well. Surface characterizations such as protein adsorptionand platelet adhesion were observed by scanning electron microscopy. 2.Cyto-compatibility test: Human umbilical vein endothelial cells(HUVECs) were cultured in the medium with tested slices for 72 hours.Adhesion of HUVECs was evaluated with light microscopy and withfluorescence microscope after double-staining of Ki67 or fibronectin. Results 1. The hemolysis test: White blood count (WBC), red bloodcount (RBC) and platelet count (PC) were normal and no difference wasobserved between groups. The hemolysis rates of biomaterials were lessthan 5%. Chitosan/r-hirudin and chitosan/heparin significantly prolongedPT, APTT and TT than those of other groups. The protein adsorption,platelet adhesion, and thrombus formation were reduced bychitosan/r-hirudin and chitosan/heparin. Furthermore, there wasdose-effect relationship of differential concentration chitosan/r-hirudincoated. However, we observed no significant difference in differentialconcentration of chitosan/heparin. 2. Cyto-compatibility test: After 72hours of incubation, without abnormal morphlogy, HUVECs were able togrow on to all kinds of slices. The adhesion of the cells on the slices byfluorescence microscopy through the application of fibronectionimmunofluorescent antibody labeled HUMECs decreased as following:chitosan/fibronectin＞chitosan＞uncoating＞chitosan/r-hirudin＞chitosan/he--parin. The proliferation of the cells on the slices by fluorescencemicroscopy through the application of Ki67 immunofluorescent antibodylabeled HUMECs decreased as following: chitosan/fibronectin＞chitosan=uncoating＞chitosan/r-hirudin＞chitosan/heparin. The cells grown on thesurface of chitosan/heparin were not as good as other groups.Conclusions Adhesion and Proliferation of HUVECs could enhance bychitosan/fibronectin, but the PT, APTT and TT were not prolonged.Thrombus formation on the surface of Nitinol slices was reduced by thechitosan/r-hirudin and chitosan/heparin. However, compared withchitosan/heparin, chitosan/r-hirudin could decrease the effects ofthrombogenicity and increase the effects of endothelialisation. Section TwoThe occurrence, treatment and risk factors of transientpost-procedure arrhythmias after trans-catheter closure ofperimembranous ventricular septal defects (PMVSDs)Objective To explore the occurrence, treatment and risk factors ofpost-procedure arrhythmias after trans-catheter closure with symmetrymembranous ventricular septal defect occluder (sMVSDO).Methods A retrospective analysis was performed on 124 PMVSDs patientssuccessfully underwent trans-catheter closure with sMVSDO in thedepartment of Cardiology in the First Affiliated Hospital of Nanjing MedicalUniversity from September 2003 to December 2006. Records of thefollowing data: (1) The basic ECG parameters (such as median heart rate(mHR), PR interval, QRS width and QTc values) and various types ofarrhythmias detected by ECG, Holter and electrocardio-monitor before andafter procedure; (2)The position, shape and size of PMVSDs and thedistance from the lower margin of the defects to septal leaflet of the tricuspidvalve(DLDTTV) were measured by echocardiography; (3) Right ventricularand pulmonary artery systolic pressure were measured by right cardiaccatheterization, and the shape, size of the defects and the distance from theupper margin of defects to the ring of right aortic valve (DUDTRAV) weremeasured by ventricular angiography; (4) Analysis the risk factors fornewly observed post-procedure arrhythmias.Results (1) QRS width and mHR by ECG were significantly different between before-and post-procedure in PMVSD patients (P＜0.05), but PRinterval and QTc values were no different; (2)55 PMVSD patients (44.4%)developed various types of newly observed arrhythmias after trans-catheterintervention with sMVSDO within 10 days, which included complete andincomplete right bundle branch block in 21 cases (16.9%), nonparoxysmalatrioventricular junctional tachycardia in 15 cases (12.1%), prematureventricular beats in 11 cases (8.9%), nonparoxysmal ventricular tachycardiain 11 cases (8.9%), atrioventricular block in 9 cases (7.3%), complete orincomplete left bundle branch block in 7 cases (5.6%) and atrial prematurebeats in 3 cases (2.4%); (3) Except the patients with advanced orⅢdegreeatrioventricular block treated by dexamethasone or temporary pacing, otherpatients only need bedside ECG monitor, extend hospitalization, andprevention of occurrence of accidents; (4) The post-procedure arrhythmiaswere prone to develop in the following conditions: a. The DUDTRAV wasmore than 3.0mm or the DLDTTV was smaller than 1.9mm in PMVSDpatients with aneurysmatic formation; b.The DUDTRAV was more than4.2mm or the DLDTTV was smaller than 2.1mm in PMVSD patientswithout aneurysmatic formation; c. The diameter of PMVSD withoutaneurysmatic formation was more than 4.2mm or the diameter of device wasmore than 7.1mm; (5) The DLDTTV was a risk factor of post-procedurearrhythmias, while the DUDTRAV was only related to the development ofcomplete, incomplete right bundle branch block or nonparoxysmaljunctional tachycardia.Conclusions About 45% PMVSD patients developed various types ofnewly observed arrhythmias within 10 days after trans-catheter interventionwith sMVSDO. Except the patients with advanced andⅢdegree atrioventricular block, other patients only need bedside ECG monitor, extendhospitalization. The DLDTTV was a risk factor of post-procedurearrhythmias, while the DUDTRAV was only related to complete, incompleteright bundle branch block or nonparoxysmal ventricular tachycardia. It wasimportant to screen the high-risk patients and to avoid post-procedurearrhythmias through measurement of the DUDTRAV or DLDTTV.