Efficacy of radiofrequency catheter ablation for premature ventricular contractions in children.

PURPOSE: This study evaluated the efficacy and safety of transcatheter radiofrequency ablation (RFCA) in treating ventricular premature contractions (PVCs) in children, summarized the countermeasures during intraoperative ventricular fibrillation (VF), and improved the safety of ventricular premature treatment. METHODS: A retrospective analysis was conducted on 75 children with PVCs who received RFCA in the Second Affiliated Hospital of Wenzhou Medical University from January 2010 to April 2019. Data including age, sex, body weight, ejection fraction, left ventricular end diastolic diameter, burden and number of PVCs/24 h, origin of PVCs, and its complications were collected. Paired t test was used to compare changes in cardiac function before and after surgery. RESULTS: Among the 75 cases treated with RFCA, 68 were successfully ablated, giving a success rate of 90.67%. After ablation, the left ventricular ejection fraction (LVEF) of the children was 69.13 ± 3.81%, which was significantly higher than that before surgery (69.13 ± 3.81% vs. 66.21 ± 3.22%, P = 0.012). One of the patients experienced VF during the operation, with no other complications. The initial locus of origin was the anterior septum of the right ventricular outflow tract, but VF occurred during the ablation process. Mean follow-up time was 39 ± 33 months, with two recurrent cases (2.94%). CONCLUSIONS: Performing RFCA in children is safe and effective, with a low recurrence rate and few complications. VF is not an indication to cease surgery; the key to eliminating complications is repositioning the catheter and finding a more accurate origin point.

Oxidised Low-Density Lipoprotein and Its Receptor-Mediated Endothelial Dysfunction Are Associated with Coronary Artery Lesions in Kawasaki Disease.

The study aimed to investigate the role of oxidised low-density lipoprotein (oxLDL)/lectin-like-oxLDL receptor-1 (LOX-1) in coronary artery lesions (CALs) in Kawasaki disease (KD) and of plasma oxLDL concentration in the early prediction of CALs in KD. This prospective study included 80 KD patients, 20 febrile and 20 healthy children. oxLDL, LOX-1 and other parameters were analysed in the acute phase. Plasma oxLDL concentration and LOX-1 mRNA expression in peripheral blood mononuclear cells (PBMCs) were significantly increased in KD patients compared with febrile and healthy children (P < 0.001 and P = 0.022, respectively), particularly in the group with CALs (P < 0.001 and P = 0.027, respectively). Coronary Z-score was significantly correlated with plasma oxLDL concentration and LOX-1 mRNA expression (r = 0.739 and 0.637, respectively; P < 0.01). The sensitivity and specificity of predicting CALs were 71.4% and 77.2%, respectively, at plasma oxLDL concentration ≥ 12.38 mU/L. oxLDL/LOX-1 may be involved in CAL development. The plasma oxLDL concentration in the acute phase is a potentially useful biological indicator for predicting CAL in KD patients.

Microarray analysis reveals key genes and pathways in Tetralogy of Fallot.

The aim of the present study was to identify key genes that may be involved in the pathogenesis of Tetralogy of Fallot (TOF) using bioinformatics methods. The GSE26125 microarray dataset, which includes cardiovascular tissue samples derived from 16 children with TOF and five healthy age­matched control infants, was downloaded from the Gene Expression Omnibus database. Differential expression analysis was performed between TOF and control samples to identify differentially expressed genes (DEGs) using Student's t­test, and the R/limma package, with a log2 fold­change of >2 and a false discovery rate of <0.01 set as thresholds. The biological functions of DEGs were analyzed using the ToppGene database. The ReactomeFIViz application was used to construct functional interaction (FI) networks, and the genes in each module were subjected to pathway enrichment analysis. The iRegulon plugin was used to identify transcription factors predicted to regulate the DEGs in the FI network, and the gene­transcription factor pairs were then visualized using Cytoscape software. A total of 878 DEGs were identified, including 848 upregulated genes and 30 downregulated genes. The gene FI network contained seven function modules, which were all comprised of upregulated genes. Genes enriched in Module 1 were enriched in the following three neurological disorder­associated signaling pathways: Parkinson's disease, Alzheimer's disease and Huntington's disease. Genes in Modules 0, 3 and 5 were dominantly enriched in pathways associated with ribosomes and protein translation. The Xbox binding protein 1 transcription factor was demonstrated to be involved in the regulation of genes encoding the subunits of cytoplasmic and mitochondrial ribosomes, as well as genes involved in neurodegenerative disorders. Therefore, dysfunction of genes involved in signaling pathways associated with neurodegenerative disorders, ribosome function and protein translation may contribute to the pathogenesis of TOF.

Nerve growth factor-induced Akt/mTOR activation protects the ischemic heart via restoring autophagic flux and attenuating ubiquitinated protein accumulation.

The dysregulation of autophagy is related to a variety of cardiovascular diseases, such as myocardial ischemia/reperfusion (I/R). Nerve growth factor (NGF) has been shown to have therapeutic potential in ischaemic heart injury. In this study, we demonstrate that NGF administration can accelerate autophagic flux and attenuate protein ubiquitination in myocardial I/R heart. Our results showed that NGF could restored heart function and decreased the apoptosis of cardiomyocytes which induced by myocardial I/R injury. The protective effect of NGF is associated with the inhibition of autophagy related proteins. On another hand, NGF enhances the clearance of ubiquitinated protein and increases the survival of myocardial cell in vivo and in vitro. Additionally, NGF could activate the PI3K/AKT and mTOR signaling pathways. These results suggested that the cardioprotective effect of NGF is related to the restoration of autophagic flux and attenuation of protein ubiquitination via the activation of PI3K/AKT and mTOR pathway.

[Expression and role of urotensin II on the lung of patients with pulmonary hypertension with congenital heart disease].

OBJECTIVE: To observe the expression of urotensin II (UII) on the lung of patients with pulmonary hypertension (PH) with congenital heart disease and investigate the meaning of this phenomenon. METHOD: Thirty eight patients with CHD were divided into three groups according to pulmonary arterial systolic pressure (PASP) measured in cardiac catheterization and surgery: normal pulmonary pressure group (N group, PASP < 30 mm Hg, n = 10), mild PH group (M group, PASP ≥ 30 mm Hg, n = 15), severe or moderate PH group (S group, PASP ≥ 50 mm Hg, n = 13). The expression of UII protein and UII mRNA in pulmonary arterioles were measured separately by immunohistochemical (IHC) analysis and in situ hybridization (ISH) analysis. RESULT: (1) The results of UIIIHC staining: The UII protein expression of group M was higher than that of group N (20.22 ± 3.58 vs. 14.34 ± 2.18, P < 0.01), but less than group S (20.22 ± 3.58 vs. 28.92 ± 3.22, P < 0.05). (2) The results of UIIISH mRNA staining were similar to IHC staining, the A value of group M was higher than group N (12.51 ± 2.02 vs. 8.85 ± 1.41, P < 0.05), less than that of group S(12.51 ± 2.02 vs. 25.35 ± 4.33, P < 0.01). (3) Correlation study: there was a positive correlation between the A values of UIIIHC and pulmonary hypertension (r = 0.64, P < 0.01, n = 38), a positive correlation between the A values of UIIISH and pulmonary hypertension (r = 0.58, P < 0.01, n = 38). CONCLUSION: There was the expression of Urotensin II protein and mRNA in the lung of pulmonary hypertension patients with congenital heart disease, and these expression may involve the formation of pulmonary hypertension of congenital heart disease.

[Effects of carvedilol on cardiomyocyte apoptosis in autoimmune myocarditis in mice].

OBJECTIVE: To observe the effects of carvedilol on the expression of Bcl-2, Bax and Fas in autoimmune myocarditis (AM). METHODS: A total of 60 inbred male BALB/C mice 4 - 5 weeks of age were divided at random into 3 groups as follows: AM group (n = 20), carvedilol group (n = 20) and control group (n = 20). The mice were sacrificed after gathering blood specimens by taking out the eyeballs and hearts tissue. The histological and ultrastructural changes were observed under light microscope and electron microscope. The concentrations of cardiac troponin I (cTn I) were detected by chemiluminescence immunoassay (CLIA). Immunohistochemistry (IHC) was performed to analyze the contents of Bcl-2, Bax and Fas, TUNEL to detect the apoptotic index in myocardial cells. RESULTS: There were large number of lymphocyte and monocyte infiltrates under light microscope and karyopyknosis and chromatin gathered along the nuclear membrane under electron microscope in AM group. There were no inflammations and chromatin gathering in group C. Compared with control group, the Bcl-2, Bax and Fas protein expression significantly elevated in AM group (23.48 ± 2.24 vs. 6.64 ± 1.60, 26.15 ± 2.02 vs. 5.09 ± 0.85, 21.22 ± 3.62 vs. 5.86 ± 1.37, P < 0.01). The histopathologic scores (2.60 ± 0.31 vs. 2.02 ± 0.26, P < 0.05) and karyopyknosis of carvedilol group decreased as compared with AM group. The Bcl-2, Bax and Fas protein expression (17.13 ± 1.94 vs. 23.48 ± 2.24, 17.66 ± 2.62 vs. 26.15 ± 2.02, 16.79 ± 2.83 vs. 21.22 ± 3.62, P < 0.05), AI [(16.61 ± 4.67)% vs. (24.51 ± 4.70)%, P < 0.05] and contents of cTnI [(1.878 ± 0.48) ng/ml vs. (1.102 ± 0.23) ng/ml, P < 0.05] also decreased in carvedilol group compared with AM group. CONCLUSION: Carvedilol could protect against AM by alleviating cardiomyocyte apoptosis.

[Implication of N-terminal pro-B-type natriuretic peptide and Tei index of left ventricle changes in children with ventricular septal defect treated by transcatheter interventional therapy].

OBJECTIVE: To explore the implication of the dynamic changes of plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) level and Tei index of left ventricle (LV) in children with ventricular septal defect (VSD) treated by transcatheter closure. METHODS: Sixty children with VSD treated by transcatheter closure with VSD occluder (Group VSD) and 30 healthy children (Group C) were included in this study. The plasma concentration of NT-proBNP, Tei index of LV and left ventricle ejection fraction (LVEF) were measured in Group C and at before, 5th minute, 4th hour, 1st month, 3rd month and 6th month after VSD closure in Group VSD. RESULTS: (1) The concentration of plasma NT-proBNP was significantly increased in children with VSD before transcatheter closure compared with Group C [(229.45 ± 57.75) ng/L vs. (99.21 ± 46.86) ng/L, P < 0.01], significantly increased at 5th minute and 24th hour after transcatheter closure [(356.27 ± 96.78) ng/L and (356.38 ± 91.95) ng/L vs. (229.45 ± 57.75) ng/L, all P < 0.01], and significantly decreased at 1st month, 3rd months and 6th months after transcatheter closure [(131.33 ± 34.79) ng/L, (96.56 ± 31.55) ng/L and (93.39 ± 29.46) ng/L vs. (229.45 ± 57.75) ng/L, P < 0.05 or P < 0.01]. (2) The Tei indexes of LV in Group VSD before transcatheter closure were significantly higher than in Group C (0.45 ± 0.05 vs. 0.33 ± 0.08, P < 0.01) and Tei index was significantly increased at 24th hour, 1st month after transcatheter closure (P < 0.01) while significantly decreased at 3rd and 6th month compared with those before transcatheter closure (0.34 ± 0.07 and 0.34 ± 0.06 vs. 0.45 ± 0.05, all P < 0.01). (3) There is a positive correlation between the changes of the plasma concentration of NT-proBNP and the change of Tei index of LV before and after transcatheter closure (r = 0.653, P < 0.05). CONCLUSION: Tei index of LV and NT-proBNP can monitor cardiac function changes in children with VSD before and after transcatheter closure.

[Expression of cystathionine-γ-lyase/hydrogen sulfide pathway in CVB3-induced myocarditis in mice].

OBJECTIVE: Previous studies have shown that hydrogen sulfide (H2S) plays key roles in a number of biological processes, including vasorelaxation, inflammation, apoptosis, ischemia/reperfusion and oxidative stress, which are involved in the pathogenesis of myocarditis. This study aimed to examine the expression of cystathionine-γ-lyase(CSE)/H2S pathway in mice with viral myocarditis. METHODS: Six-week-old inbred male mice were randomly assigned to control (n=25) and myocarditis group (n=30). The myocarditis and the control groups were inoculated intraperitoneally with 0.1 mL 10-5.69TCID50/mL CVB3 or vehicle (PBS) alone respectively. Ten mice were sacrificed 4 and 10 days after injection. Blood and heart specimens were harvested for measuring the content of serum H2S and the H2S production rates in cardiac tissues. Heart sections were stained with hematoxylin and eosin. Immunohistochemisty was used to detect the CSE protein expression in the heart. RESULTS: In the myocarditis group, the serum H2S content and H2S production rates in cardiac tissues were significantly higher than those in the control group 4 and 10 days after injection (P<0.05). The expression of CSE protein in the heart in the myocarditis group was also significantly higher than that in the control group (P<0.05). CONCLUSIONS: CSE and its downstream production H2S increase in mice with acute viral myocarditis. The increased expression of CSE/H2S pathway might be involved in the pathogenesis of viral myocarditis.

[Heart rate variability, adrenomedullin and B-type natriuretic peptide before and after transcatheter closure in children with patent ductus arteriosus].

OBJECTIVE: To observe the changes of heart rate variability (HRV), adrenomedullin (ADM) and B-type natriuretic peptide (BNP) before and after transcatheter closure in children with patent ductus arteriosus. METHODS: HRV spectral values (TF, VLF, LF, HF, LF/HF) were detected by 24 dynamic electrocardiogram and the concentrations of plasma ADM and BNP were measured in 55 children with patent ductus arteriosus (Group PDA, n = 55) before and 3(rd) day, 3(rd) month after transcatheter closure therapy, and in 60 normal children (Group C). RESULTS: (1) Compared with Group C, the HRV spectral values (TF, VLF, HF) were significantly lower (all P < 0.01), LF/HF and the concentrations of plasma ADM, BNP were significantly higher in patients with PDA before transcatheter closure (all P < 0.01). (2) Compared with the values before transcatheter closure values, plasma ADM were significantly reduced at 3(rd) day and 3(rd) month after transcatheter closure (P < 0.01), the HRV spectral values (TF, VLF, HF) were significantly increased while LF/HF and plasma BNP were significantly decreased at 3(rd) month after transcatheter closure (P < 0.01 or P < 0.05). CONCLUSIONS: HRV and plasma ADM, BNP improved significantly post transcatheter closure in children with patent ductus arteriosus.

[Changes of serum leptin and vascular endothelial growth factor in children with congenital heart disease].

OBJECTIVE: To study the changes of serum leptin (LEP) and vascular endothelial growth factor (VEGF) in children with congenital heart disease(CHD) and their roles in CHD. METHODS: Forty-eight children with acyanotic CHD (ACHD group), 20 age-matched children with cyanotic CHD (CCHD group) and 20 healthy children (control group) were enrolled. The ACHD group was subdivided into two groups with (n=20) or without concurrent heart failure (n=28). Serum LEP, VEGF, total protein and albumin levels and body mass index (BMI) were measured. RESULTS: Serum total protein and albumin levels were not apparently different in all CHD children from healthy controls, but there was a significant difference in the BMI between them (p<0.01). Serum LEP and VEGF levels and the ratio of LEP/BMI in all CHD children were significantly higher than those in healthy controls (p<0.01). Compared with the ACHD group without heart failure, the serum LEP and VEGF levels and the ratio of LEP/BMI in the CCHD and the ACHD with heart failure groups increased significantly (p<0.01). In the ACHD group, serum LEP level was positively correlated with BMI (p<0.01). In the CCHD group, there were positive correlations between serum LEP level and serum VEGF level (p<0.01) and between hemoglobin concentration and serum VEGF level (p<0.01). Arterial oxygen saturation was negatively correlated with serum VEGF (p<0.01) and LEP levels (p<0.01) in the CCHD group. CONCLUSIONS: Both VEGF and LEP play roles in the pathophisiological process of CHD. VEGF and LEP are associated with the development of heart failure in children with ACHD.

[Reducing plasma homocysteic acid lowers serum C-reactive protein level in children with Kawasaki disease].

OBJECTIVE: To investigate the effect of plasma homocysteic acid (HCA) reduction on serum C-reactive protein (CRP) level in children with Kawasaki disease (KD). METHODS: Seventy-six children with KD were divided into 2 equal groups for treatment with aspirin and IVIG, or with vitamin B6 and folic acid besides in addition to aspirin and IVIG. Serum CRP level was tested before and after the treatments, and plasma HCA level was also measured after the treatments. RESULTS: Serum CRP level was comparable between the two groups before the treatment, but significantly reduced after vitamin B6 and folic acid treatment (7.56-/+2.94 mg/L vs 12.23-/+4.16 mg/L, P<0.05). Additional vitamin B6 and folic acid treatment significantly lowered plasma HCA level (4.56-/+1.14 micromol/L vs 7.79-/+1.79 micromol/L, P<0.05), and correlation analysis demonstrated a positive correlation between plasma HCA and serum CRP levels (r=0.697, P<0.01). CONCLUSION: Lowering plasma HCA can decrease serum CRP in children with KD to enhance the therapeutic effect.

[Effects of hemoglobin oxygenase-1 inhibitor zinc protoporphyrin IX on acute viral myocarditis in mice].

OBJECTIVE: To investigate the role of heme oxygenase-1 (HO-1) and its catalyst carbon monoxide (CO) in the development of myocardial damage and the effects of zinc protoporphyrin IX (ZnPPIX), an inhibitor of HO-1 on myocardium of mice with acute viral myocarditis. METHODS: A total of 112 inbred male Balb/C mice 4 - 6 weeks of age were divided randomly into 3 groups: the control group (C group, n = 32), the viral myocarditis group (V group, n = 40) and ZnPPIX group (Z group, n = 40). The Z and V groups were inoculated intraperitoneally (i.p.) with 0.1 ml of 10(-4.36) tissue culture infectious dose 50% (TCID(50))/ml Coxsackie virus B3 (CVB(3)) to produce viral myocarditis model on day 0, C group was injected i.p. with virus-free 1640 culture culture medium 0.1 ml at the same time, then operation was done as follows: the mice of group C and group V were injected i.p. with 0.1 ml NS each day. The mice of group Z were injected i.p. with 40 micromol per kilogram of body weight ZnPPIX (HO-1 inhibitor) qod. Eight mice of each group were sacrificed on days 4, 8, 15 and 21, respectively. The blood specimens were collected by taking out the eyeballs to test for the content of carboxyhemoglobin (COHb) using spectrophotometry and cardiac troponin I (cTnI) using chemiluminescent immunoassay. The hearts tissue slides were also stained by immunohistochemistry (IHC) for HO-1 and in situ hybridization (ISH) for HO-1 mRNA. The histological and ultrastructural changes were observed under light and electron microscopes. RESULTS: (1) The histopathological changes of myocardial cells: in the V and Z groups myocardial inflammatory cells infiltration reached the peak on day 8, the Z group histopathological scores were significantly lower than those in V group on day 8 (2.40 +/- 0.31 vs. 1.73 +/- 0.24, P < 0.01) and on day 15 (1.78 +/- 0.29 vs. 1.43 +/- 0.23, P < 0.05). No inflammation was present in group C. (2) The changes of serum cTnI level in both V and Z groups were significantly higher than those in C group on day 4, 8 and 15 (P < 0.01). The level in Z group was significantly lower than that in V group on day 4 [(6.074 +/- 1.475) ng/ml vs (7.911 +/- 1.225) ng/ml, P < 0.05] and day 8 [(0.821 +/- 0.294) ng/ml vs (1.480 +/- 0.454) ng/ml, P < 0.05]. (3) The changes of blood COHb level: compared with V group, in Z group the COHb level was lower on day 4 (P < 0.05) and day 15 (P < 0.01) after CVB(3) inoculation. Surprisingly, in Z group COHb level elevated suddenly on day 8 and showed conspicuously higher than that of V group (P < 0.01). (4) The result of HO-1 IHC staining: in both V and Z group myocardial cells had positive expression, while C group did not. (5) The results of HO-1 ISH were similar to those of HO-1 IHC, the A values of group Z was significantly lower than that of group V on day 4, 15 and 21(P < 0.01), but on day 8 it was higher than that of group C (P < 0.05). CONCLUSION: HO-1 inhibitor, ZnPP not only could inhibit HO-1 overexpression but also could induce HO-1 expression temporarily and protect against myocardial injury at the early stage of acute viral myocarditis.