Chinese consensus on the use of antiarrhythmic drugs for rhythm control in atrial fibrillation / 中华内科杂志

Rhythm control is crucial part of comprehensive management of atrial fibrillation (AF). Rhythm control can reduce the burden of AF effectively, reduce symptoms, and improve the prognosis in early AF. Antiarrhythmic drugs (AADs) are the first-line treatment for rhythm-control strategies. This consensus focuses on the principle of rhythm control in AF, the characteristics of AADs, and the medication recommendations for patients in different populations suffering from AF. Hence, this consensus aims to support clinical decision-making for AF therapy.

Prevalence and incidence of heart failure among community in China during a three-year follow-up / 老年心脏病学杂志（英文版）

BACKGROUND@#Epidemiological surveys on heart failure (HF) in Chinese community are relatively lacking. This study aimed to estimate the prevalence and incidence of HF among community residents in southern China.@*METHODS@#Baseline data of this prospective study was collected from 2015 to 2017 among 12,013 permanent residents aged ≥ 35 years in Guangzhou, China. The same survey process was carried out for individuals aged ≥ 65 years after a three-year follow-up.@*RESULTS@#The overall prevalence of HF in community residents aged ≥ 35 years was 1.06%. Male had significantly higher risk of HF prevalence [odds ratio (OR) = 1.50, P = 0.027]. The gender-adjusted risk of HF was 1.48 times higher per 10 years aging. HF prevalence was statistically associated with atrial fibrillation, valvular heart disease, hypertension and chronic obstructive pulmonary disease after adjusting for age and gender (OR = 8.30, 5.17, 1.11, 2.28, respectively; all P < 0.05). HF incidence in individuals aged ≥ 65 years were 847 per 100,000 person-years. Baseline atrial fibrillation, valvular heart disease, and diabetes mellitus were risk factors for HF incidence for individuals aged ≥ 65 years adjusting for age and gender (OR = 5.05, 3.99, 2.11, respectively; all P < 0.05). Besides, residents with new-onset atrial fibrillation and myocardial infarction were at significantly higher risk of progression to HF (OR = 14.41, 8.54, respectively; all P < 0.05).@*CONCLUSIONS@#Both pre-existing and new-onset cardiovascular diseases were associated with HF incidence in southern China. Management of related cardiovascular diseases may be helpful to reduce the incidence of HF.

Involvement of Src kinase in the down-regulation of ultra-rapid delayed rectifier K(+)current induced by tumor necrosis factor-α in cardiomyocytes / 中华心血管病杂志

Objective: To investigate whether inflammatory factor tumor necrosis factor-α (TNF-α) is involved in the electrical remodeling of cardiomyocytes by regulating ultra-rapid delayed rectifier K(+) current (I(kur)) and the role of Src kinase. Methods: H9c2 cells, embryonic cardiomyocytes of rat, were cultured in Dulbecco's modified Eagle's medium (DMEM) and atrium-derived HL-1 cells were cultured in Claycomb medium. Both H9c2 and HL-1 cells were cultured at 37 ℃ with 5% CO(2). Cells cultured in normal conditions without additional treatment served as control group. Experimental groups were treated with different concentration of TNF-α (25 or 50 or 100 ng/ml) for 24 hours. To study whether Src specific inhibitor PP1 could abrogate the effect of TNF-α, cells were pre-treated with 10 μmol/L PP1 for 1 hour, followed by TNF-α (100 ng/ml) for 24 hours. Western blot and the whole cell patch clamp technique were used to detect the protein expression of Kv1.5 and Src and I(kur) in each group. Results: (1) In H9c2 cells, high concentration of TNF-α treatment (100 ng/ml) significantly reduced the Kv1.5 protein expression compared with control group and TNF-α 25 ng/ml group (both P<0.05). Compared with control group, the expression of p-Src protein was higher in 25 ng/ml, 50 ng/ml, 100 ng/ml TNF-α group (all P<0.05), but there was no statistical difference in the expression of Src protein among groups (P>0.05). In addition, the current density of I(kur) was decreased in 50 ng/ml, 100 ng/ml TNF-α group (both P<0.05). Furthermore, the expression of Kv1.5 protein and the current density of I(kur) were increased in PP1+TNF-α group compared with TNF-α 100 ng/ml group (both P<0.05). There was no statistical difference in the expression of Kv1.5 protein and the current density of I(kur) between the control group and PP1+TNF-α group (both P>0.05). (2) In atrium-derived HL-1 cells, the expression of Kv1.5 protein was reduced in 100 ng/ml TNF-α group compared with control group and TNF-α 25 ng/ml group (both P<0.01). In addition, the expression of p-Src protein was increased in TNF-α 100 ng/ml group compared with control group (P<0.05), but there was no statistical difference in the protein expression of Src among groups (P>0.05). The expression of Kv1.5 protein was increased in PP1+TNF-α group compared with TNF-α 100 ng/ml group (P<0.05). Conclusion: TNF-α is involved in the pathogenesis of atrial fibrillation, probably via decreasing I(kur) current density in atrium-derived myocytes through the activation of Src kinase.

Right ventricular outflow tract septal pacing versus apical pacing: A prospective, randomized, single-blind 5-years follow-up study of ventricular lead performance and safety / 华中科技大学学报（医学）（英德文版）

Lead placement for ventricular pacing variably impacts the physiological benefit of the patient. This study evaluated the ventricular lead performance and safety of right ventricular outflow tract septal pacing in patients with bradyarrhythmia in South China over 60-month follow-up. Totally, 192 patients (108 males, and 84 females, 63±21 years old) with bradyarrhythmia were randomly divided into two groups. The right ventricular outflow tract septum (RVOTs) group had lead placement near the septum (n=97), while the right ventricular apex (RVA) group had a traditional apical placement (n=95). RV septal lead positioning was achieved with a specialized stylet and confirmed using fluoroscopic projection. All patients were followed up for 60 months. Follow-up assessment included stimulation threshold, R-wave sensing, lead impedance and lead complications. The time of electrode implantation in both the ROVTs and RVA groups were significantly different (4.29±0.61 vs. 2.16±0.22 min; P=0.009). No differences were identified in threshold, impedance or R-wave sensing between the two groups at 1st, 12th, 36th and 60th month during the follow-up period. No occurrence of electrode displacement, increased pacing threshold or inadequate sensing was found. The long-term active fixation ventricular electrode performance in RVOTs group was similar to that in RVA group. RVOTs pacing near the septum using active fixation electrodes may provide stability during long-term follow-up period.

Role of tumor necrosis factor-alpha in the pathogenesis of atrial fibrillation / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Tumor necrosis factor-alpha (TNF-α) is a pleiotropic proinflammatory cytokine and contributes to many kinds of cardiovascular diseases via its receptors (TNFR1/TNFR2). We hypothesize that TNF-α plays a role in the pathogenesis of chronic atrial fibrillation (AF).</p><p><b>METHODS</b>Sixty-seven consecutive patients who were scheduled to have cardiac surgery were enrolled into the study. Thirty-one patients with rheumatic heart disease (RHD) and AF were enrolled as study group (AF group). The sinus rhythm (SR) control groups consisted of 20 patients with RHD and 16 patients with coronary artery disease (CAD). Peripheral blood sample was collected before the operation. About 5 mm(3) left atrial tissue was disserted during the operation and was separated into three parts for Western blotting, real time polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) analysis.</p><p><b>RESULTS</b>Compared with the controls (RHD SR and CAD SR), the levels of TNF-α ((14.40 ± 5.45) pg/ml vs. (4.20 ± 3.19) pg/ml vs. (2.68 ± 2.20) pg/ml, P = 0.000) and its soluble receptor 1 (sTNFR1) ((1623.9 ± 558.6) pg/ml vs. (1222.3 ± 175.6) pg/ml vs. (1387.5 ± 362.2) pg/ml, P = 0.001) in plasma were higher in patients with AF. TNF-α level had positive correlation with the left atrial diameter (LAD) (r = 0.642, P = 0.000). Western blotting analysis showed that the protein levels of TNF-α (0.618 ± 0.236 vs. 0.234 ± 0.178 vs. 0.180 ± 0.103, P = 0.000) were higher in patients with AF. The RT-PCR analysis results demonstrated that the mRNA expression of TNF-α (0.103 ± 0.047 vs. 0.031 ± 0.027 vs. 0.023 ± 0.018, P = 0.000) increased in patients with AF. IHC analysis displayed that, comparing to the SR, the expression of TNF-α (0.125 ± 0.025 vs. 0.080 ± 0.027 vs. 0.070 ± 0.023, P = 0.000) increased in the AF group. The protein level and mRNA expression of TNF-α also had positive correlation with left atrium diameter (LAD) (r = 0.415, P = 0.000 and r = 0.499, P = 0.000).</p><p><b>CONCLUSIONS</b>The results revealed that TNF-α elevated in the plasma and left atrial tissue and had positive correlation with LAD in patients of chronic AF. TNF-α might involve in the pathogenesis of chronic AF.</p>

Multi-center clinical trial on efficacy of national-made radiofrequency ablation catheter for the treatment of atrioventricular nodal reentrant tachycardia and atrioventricular reentrant tachycardia / 中华心血管病杂志

<p><b>OBJECTIVE</b>The aim of this trial is to compare the efficacy and safety between national-made and imported ablation catheters for the treatment of atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT).</p><p><b>METHOD</b>A total of 1342 patients with AVNRT or AVRT were randomly treated with national-made ablation catheter (Group 1, n = 672) or imported ablation catheter (Group 2, n = 670).</p><p><b>RESULTS</b>The immediate ablation success rate was similar in Group 1 and Group 2 (97.9% vs. 99.1%, P > 0.05). There were also no significant differences in the procedure time [(68 +/- 36) min vs. (67 +/- 34) min], the fluoroscopic time [(14 +/- 14) min vs. (10 +/- 11) min], the number of energy delivery [(4.5 +/- 4.5) beats vs. (4.6 +/- 3.9) beats], the ablation time [(260 +/- 218) s vs. (257 +/- 207) s] and the score of ablation catheter performance evaluation [(4.4 +/- 0.5) vs. (4.5 +/- 0.4) ] between the two groups (all P > 0.05). Three patients developed pericardial effusion (1 in Group 1 and 2 in Group 2, P > 0.05). Incidence of recurrence of tachycardia during the 3 months follow up was similar between the 2 groups (14 in Group1 vs. 16 in Group 2, P > 0.05).</p><p><b>CONCLUSION</b>National-made and imported radiofrequency ablation catheters have similar efficacy and safety for treatment of AVNRT and AVRT.</p>

Changes of endothelial function indices and their relation to platelet activation in idiopathic atrial fibrillation / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes of endothelial function indices and their relation to platelet activation in patients with idiopathic atrial fibrillation (AF).</p><p><b>METHODS</b>We studied 61 patients with idiopathic AF with 34 age- and sex-matched healthy persons as control. Platelet counts in the blood were tested, and plasma levels of NOx were analyzed using Griess method. The plasma levels of von Willibrand factor (vWF) and soluble P-selectin (sP-selectin) were determined using enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>Compared to healthy control, the patients with idiopathic AF had significantly lower levels of plasma NOx (18.2-/+7.3 vs 24.3-/+7.8 micromol/L, P=0.049) and higher levels of plasma sP-selectin (25.6-/+6.2 vs 22.4-/+4.8 ng/ml, P=0.007). No significant differences were found in the platelet counts or plasma vWF levels between the two groups. A significant inverse correlation was found between plasma NOx and sP-selectin (r=-0.405, P=0.025) in patients with idiopathic AF.</p><p><b>CONCLUSION</b>AF per se may impair the endothelial function and activate platelet function, suggesting the role of endothelial dysfunction in activated platelet function in AF patients.</p>

Mutation of plakophilin-2 gene in arrhythmogenic right ventricular cardiomyopathy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Arrhythmogenic right ventricular cardiomyopathy (ARVC) is one of the leading causes of sudden cardiac death. Recent studies have shown that ARVC, which is an inheritable genetic change, results from mutations in genes encoding desmosomal proteins. Plakophilin-2 is an important component of the desmosome. Because the full range of genetic variations related to ARVC is unknown and no related studies of the Chinese population have been reported, we aimed to investigate the genetic variation of plakophilin-2 in ARVC patients from the Southern Region of China.</p><p><b>METHODS</b>Genomic DNA was isolated from peripheral blood samples of all 34 ARVC patients, who were screened through a clinical evaluation. They were used to detect variations in the sequences of the plakophilin-2 genes by polymerase chain reaction amplification in combination with direct sequencing.</p><p><b>RESULTS</b>In exon-1 of the plakophilin-2 gene, a deletion mutation (c.145_148 del GACA) was found in one family pedigree. The mutation was also found in exon-2, 4, and 11 of the plakophilin-2 gene. The QT interval dispersion of the ECG was considerably longer in the mutation group than in the non-mutation group of ARVC patients, and this result was statistically significant (P < 0.05).</p><p><b>CONCLUSION</b>We discovered a plakophilin-2 mutation that prolongs the QT interval dispersion in the southern Chinese ARVC population.</p>

Left atrial size and function after radiofrequency catheter ablation for paroxysmal atrial fibrillation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the impact of radiofrequency catheter ablation on left atrial (LA) size and function in patients with paroxysmal atrial fibrillation (PAF) and whether there is any difference between segmental pulmonary vein ostial isolation (SPVI) and circumferential pulmonary vein ablation (CPVA).</p><p><b>METHODS</b>Sixty-six patients with highly symptomatic atrial fibrillation were assigned to undergo either SPVI or CPVA. Transthorax echocardiography was performed before, 1 day, 1 months and 3 months after the procedure. LA dimension, LA area, late diastolic peak velocity of mitral valve inflow (A) and peak atrial systolic mitral annulus velocity (A') were recorded.</p><p><b>RESULTS</b>Of 66 consecutive patients with symptomatic PAF, 30 patients underwent SPVI and 36 underwent CPVA. After a mean follow-up of (315 +/- 153) days, 21 patients (70%) after SPVI and 28 patients (75%) after CPVA were free of atrial tachyarrhythmia. As compared with the baseline, LA area decreased at 1-month after ablation in SPVI group and at 3-month in CPVA group. LA dimension decreased also in SPVI group, but did not in CPVA group. A velocity and A' velocity declined remarkably 1 day after CPVA, and restored 3 months later. The former went back to the level of baseline, and the latter exceeded it apparently. In SPVI group, A velocity increased at 1-month, and maintained in 3-month after ablation. A' velocity increased at 3-month after ablation. No reduction of A velocity or A' velocity was found after SPVI.</p><p><b>CONCLUSIONS</b>This study demonstrated a decrease in LA area and an improvement in LA systolic function 3 months after ablation for PAF. The LA damage by CPVA was more than that by SPVI, which was characterized by the reduction of LA function 1 day after procedure and the delayed improvement of LA size and functional parameters.</p>

Inhibitory effect of anti-C II TA RNase P on MHC II expression in Jurkat cells / 中国实验血液学杂志

This study was purposed to investigate the inhibitory effect of anti-C II TA M1-RNA on MHC II expression. The M1-RNA with guide sequences (GS) recognizing C II TA at 3408 site (M1-3408-GS) and C II TA target RNA (3176 - 3560) were constructed, then cloned into the pUC19 and pGEM-7zf (+) vector respectively. The recombinant M1-RNA and its target RNA were incubated in cell-free conditions. It showed that M1-3408-GS could exclusively cleave target RNA, then it was cloned into the psNAV vector. Stable transfectants of Jurkat cells with M1-3408-GS were analyzed for classical MHC II (HLA-DR, -DP, -DQ) induction in response to IFN-gamma by flow cytometry. The level of C II TA mRNA was measured by RT-PCR. The results showed that after IFN-gamma treatment, the expression of HLA-DR, HLA-DP, HLA-DQ on M1-3408-GS positive Jurkat cells decreased 83.17%, 94.12% and 84.31% respectively as compared with control. At the same time the mRNA contents of C II TA also markedly decreased (P < 0.05, t = 4.89). It is concluded that anti-C II TA M1-RNA (M1-3408-GS) inhibits C II TA, decreases itself mRNA content and so suppresses expression of MHC II molecules regulated by C II TA.