Yigang Li

Electrophysiological Findings During Ablation of Persistent Atrial Fibrillation With Electroanatomic Mapping and Double Lasso Catheter Technique

Background— Pulmonary veins (PVs) can be completely isolated with continuous circular lesions (CCLs) around the ipsilateral PVs. However, electrophysiological findings have not been described in detail during ablation of persistent atrial fibrillation (AF). Methods and Results— Forty patients with symptomatic persistent AF underwent complete isolation of the right-sided and left-sided ipsilateral PVs guided by 3D mapping and double Lasso technique during AF. Irrigated ablation was initially performed in the right-sided CCLs and subsequently in the left-sided CCLs. After complete isolation of both lateral PVs, stable sinus rhythm was achieved after AF termination in 12 patients; AF persisted and required cardioversion in 18 patients. In the remaining 10 patients, AF changed to left macroreentrant atrial tachycardia in 6 and common-type atrial flutter in 4 patients. All atrial tachycardias were successfully terminated during the procedure. Atrial tachyarrhythmias recurred in 15 of 40 patients at a median of 4 days after the initial ablation. A repeat ablation was performed at a median of 35 days after the initial procedure in 14 patients. During the repeat study, recovered PV conduction was found in 13 patients and successfully abolished by focal ablation of the conduction gap of the previous CCLs. After a mean of 8±2 months of follow-up, 38 (95%) of the 40 patients were free of AF. Conclusions— In patients with persistent AF, CCLs can result in either AF termination or conversion to macroreentrant atrial tachycardia in 55% of the patients. In addition, recovered PV conduction after the initial procedure is a dominant finding in recurrent atrial tachyarrhythmias and can be successfully abolished.

Knockdown of microRNA-181 by lentivirus mediated siRNA expression vector decreases the arrhythmogenic effect of skeletal myoblast transplantation in rat with myocardial infarction

The arrhythmogenic effect of intracardiac skeletal myoblast (SKM) transplantation may be related to the differentiation state of SKMs. We tested the hypothesis that lentivirus mediated siRNA against the loop region of miRNA-181a could upregulate the SKMs differentiation repressor homeobox protein A11 (Hox-A11) and reduce the arrhythmias post SKM transplantation into ischemic myocardium of rats. Primary cultured SKMs were transfected with Lenti-siR-miR-181 (recombined lentivirus expressing the unique siRNA against miR-181a, LV group). Real-time PCR showed that miRNA-181a level was significantly decreased and Hox-A11 protein level significantly increased in LV group than in control group at days 5 and days 7 post Lentivirus transfection. Knockdown of miRNA-181a significantly promoted SKMs growth and attenuated the connexin43 downregulation in SKMs in vitro. Seven days after left coronary artery ligation, rats were randomized to receive intramyocardial injection of either 5x10(6) SKMs transfected with Lenti-siR-miR-181 (MI-SKMLV), 5x10(6) Lenti-siLUC SKMs (MI-SKM) or PBS (MI-PBS). Systolic function was significantly improved in both MI-SKM and MI-SKMLV groups fourteen days after injection. Incidence of inducible self-terminating ventricular tachycardia was significantly lower in MI-SKMLV than that in MI-SKM group. Engraftments of SKMs with knockdowned miRNA-181a similarly improved cardiac function as SKM transplantation but significantly decreased the arrhythmogenic effect of SKM transplantation in rats with experimental myocardial infarction.

Meta-analysis of prospective studies on the effects of nut consumption on hypertension and type 2 diabetes mellitus 对食用坚果对高血压和2型糖尿病的影响的前瞻性研究进行的meta分析

Inconclusive reports have been published on the consumption of nuts and the risk of hypertension and type 2 diabetes mellitus (T2DM). We performed a meta‐analysis of prospective studies to assess the effects of nut consumption on hypertension and T2DM risks.

Overexpression of Sema3a in myocardial infarction border zone decreases vulnerability of ventricular tachycardia post-myocardial infarction in rats.

The expression of the chemorepellent Sema3a is inversely related to sympathetic innervation. We investigated whether overexpression of Sema3a in the myocardial infarction (MI) border zone could attenuate sympathetic hyper‐innervation and decrease the vulnerability to malignant ventricular tachyarrhythmia (VT) in rats. Survived MI rats were randomized to phosphate buffered saline (PBS, n = 12); mock lentivirus (MLV, n = 13) and lentivirus‐mediated overexpression of Sema3a (SLV, n = 13) groups. Sham‐operated rats served as control group (CON, n = 20). Cardiac function and electrophysiological study (PES) were performed at 1 week later. Blood and tissue samples were collected for histological analysis, epinephrine (EPI), growth‐associated factor 43 (GAP43) and tyrosine hydroxylase (TH) measurements. QTc intervals were significantly shorter in SLV group than in PBS and MLV groups (168.6 ± 7.8 vs. 178.1 ± 9.5 and 180.9 ± 8.2 ms, all P < 0.01). Inducibility of VT by PES was significantly lower in the SLV group [30.8% (4/13)] than in PBS [66.7% (8/12)] and MLV [61.5% (8/13)] groups (P < 0.05). mRNA and protein expressions of Sema3a were significantly higher and the protein expression of GAP43 and TH was significantly lower at 7 days after transduction in SLV group compared with PBS, MLV and CON groups. Myocardial EPI in the border zone was also significantly lower in SLV group than in PBS and MLV group (8.73 ± 1.30 vs. 11.94 ± 1.71 and 12.24 ± 1.54 μg/g protein, P < 0.001). Overexpression of Sema3a in MI border zone could reduce the inducibility of ventricular arrhythmias by reducing sympathetic hyper‐reinnervation after infarction.

Effects of valsartan on ventricular arrhythmia induced by programmed electrical stimulation in rats with myocardial infarction

The impact of angiotensin II receptor blockers (ARBs) on electrical remodelling after myocardial infarction (MI) remains unclear. The purpose of the present study was to evaluate the effect of valsartan on incidence of ventricular arrhythmia induced by programmed electrical stimulation (PES) and potential link to changes of myocardial connexins (Cx) 43 expression and distribution in MI rats. Fifty‐nine rats were randomly divided into three groups: Sham (n = 20), MI (n = 20) and MI + Val (20 mg/kg/day per gavage, n = 19). After eight weeks, the incidence of PES‐induced ventricular tachycardia (VT) and fibrillation (VF) was compared among groups. mRNA and protein expressions of Cx43, angiotensin II type 1 receptor (AT1R) in the LV border zone (BZ) and non‐infarct zone (NIZ) were determined by real‐time PCR and Western blot, respectively. Connexins 43 protein and collagen distribution were examined by immunohistochemistry in BZ and NIZ sections from MI hearts. Valsartan effectively improved the cardiac function, reduced the prolonged QTc (163.7 ± 3.7 msec. versus 177.8 ± 4.5 msec., P < 0.05) after MI and the incidence of VT or VF evoked by PES (21.1% versus 55%, P < 0.05). Angiotensin II type 1 receptor expression was significantly increased in BZ and NIZ sections after MI, which was down‐regulated by valsartan. The mRNA and protein expressions of Cx43 in BZ were significantly reduced after MI and up‐regulated by valsartan. Increased collagen deposition and reduced Cx43 expression in BZ after MI could be partly attenuated by Valsartan. Valsartan reduced the incidence of PES‐induced ventricular arrhythmia, this effect was possibly through modulating the myocardial AT1R and Cx43 expression.

Safety and efficacy of zotarolimus-eluting stents in the treatment of diabetic coronary lesions in Chinese patients: The RESOLUTE-DIABETES CHINA Study: ZES in treating diabetic coronary lesion

The RESOLUTE‐DIABETES CHINA study was specifically designed to investigate the safety and efficacy of Resolute zotarolimus‐eluting stents (ZES; Medtronic, Santa Rosa, CA, USA) in the treatment of diabetic coronary lesions in the Chinese population.

Finite Element Simulation of Chain-Die Forming U Profiles with Variable Cross-Section

Roll forming has been widely used to manufacture constant cross-section products because of high quality, efficiency and low cost. It is quite epidemic in producing automobile parts made of advanced high strength steels (AHSS) nowadays. However, with the development of the vehicle industry and diversity of the products, variable cross-section profiles have attracted more and more attention. The traditional roll forming technique is difficult to meet the requirements. Chain-die forming which was introduced in recent years makes it possible. Chain-die forming is an extension of roll forming and its key characteristic is enlarging the rotation radii of the moulds, by which the deformation zone is extended. The study focused on the finite element simulations of Chain-die forming U profiles with variable cross-section, including variable width and height. The feasibility of Chain-die forming producing variable cross-section products was verified by the perfect simulation results. The advantage of Chain-die forming was that there was no need to design the intermediate moulds except the finished-profile ones, which reduced the mould quantity immensely. Then the cost was lower.

Left Atrial Appendage Intervention for the Prevention of Thromboembolic Events in Patients with Atrial Fibrillation: A Joint Consensus Document of the Chinese Society of Pacing and Electrophysiology, Chinese Society of Cardiology, Chinese Society of Arrhythmias

PreamBle Atrial fibrillation (AF) is one of the common arrhythmias and can lead to serious thromboembolic events that may affect the quality of life and even cause disability and death. For this reason, preventing the occurrence of thromboembolism events is the most important prevention and treatment strategy. Regular antithrombus treatment has acquired satisfied therapeutic effect in prevention of thromboembolic events. However, the patient compliance is poor due to long-term therapy and potential side effects caused by antithrombotic medication. It is estimated that <10% of patients with AF have regular anti-thrombotic therapy in China. Therefore, it is necessary to explore new strategies for the prevention of thromboembolic events in patients with AF in China.

Meta-analysis of prospective studies on the effects of nut consumption on hypertension and type 2 diabetes mellitus 对食用坚果对高血压和2型糖尿病的影响的前瞻性研究进行的meta分析: Nut consumption and hypertension and T2DM

Inconclusive reports have been published on the consumption of nuts and the risk of hypertension and type 2 diabetes mellitus (T2DM). We performed a meta‐analysis of prospective studies to assess the effects of nut consumption on hypertension and T2DM risks.

Impact of phosphomimetic and non-phosphorylatable mutations of phospholemman on L-type calcium channels gating in HEK 293T cells.

Background: Phospholemman (PLM) is an important phosphorylation substrate for protein kinases A and C in the heart. Until now, the association between PLM phosphorylation status and L‐type calcium channels (LTCCs) gating has not been fully understood. We investigated the kinetics of LTCCs in HEK 293T cells expressing phosphomimetic or nonphosphorylatable PLM mutants. Methods: The LTCCs gating was measured in HEK 293T cells transfected with LTCC and wild‐type (WT) PLM, phosphomimetic or nonphosphorylatable PLM mutants: 6263AA, 6869AA, AAAA, 6263DD, 6869DD or DDDD. Results: WT PLM significantly slowed LTCCs activation and deactivation while enhanced voltage‐dependent inactivation (VDI). PLM mutants 6869DD and DDDD significantly increased the peak of the currents. 6263DD accelerated channel activation, while 6263AA slowed it more than WT PLM. 6869DD significantly enhanced PLM‐induced increase of VDI. AAAA slowed the channel activation more than 6263AA, and DDDD accelerated the channel VDI more than 6869DD. Conclusions: Our results demonstrate that phosphomimetic PLM could stimulate LTCCs and alter their dynamics, while PLM nonphosphorylatable mutant produced the opposite effects.