Qijun Shan

Effects of resveratrol on number and activity of endothelial progenitor cells from human peripheral blood.

1 It has been well established that oestrogens can increase the number of endothelial progenitor cells (EPC) by anti‐apoptotic effects. Resveratrol, a polyphenolic phytoalexin extracted from grapes and wine, has been reported to act as an oestrogen receptor agonist. We hypothesize that putative phyto‐oestrogen may promote EPC proliferation and survival in vitro. 2 Endothelial progenitor cells were isolated from human peripheral blood and identified immunocytochemically. Endothelial progenitor cells were incubated with resveratrol (1, 10, 25 and 50 mmol/L) or control for specified times. Cell proliferation, migration and in vitro vasculogenesis were assayed using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetra‐zolium bromide (MTT) assay, modified Boyden chamber assay and in vitro vasculogenesis detection, respectively. 3 Resveratrol increased the number of EPC and promoted EPC proliferation, adhesion and migration in a dose‐ and time‐dependent manner. Cell number peaked at 50 mmol/L resveratrol after incubation for 24 h compared with vehicle control (61.3 ± 5.8 vs 112.8 ± 7.2, respectively; P < 0.01). 4 Furthermore, cell cycle analysis showed that 50 mmol/L resveratrol significantly increased the S phase and decreased the G0/G1 phase of EPC. In addition, resveratrol increased vascular endothelial growth factor production and further induced vasculogenesis in vitro. 5 In conclusion, resveratrol significantly induces EPC proliferation, migration and further promotes angiogenesis in vitro.

Dynamic Substrate Mapping and Ablation of Ventricular Tachycardias in Right Ventricular Dysplasia

AbstractBackground: Ablation of ventricular tachycardias in arrhythmogenic right ventricular dysplasia (ARVD-VTs) still remains a clinical challenge. We reported the value of abnormal electrophysiological substrate mapping for guiding ablation of ARVD-VTs using a non-contact mapping system. Methods and Results: Dynamic substrate mapping was performed in three male ARVD patients during sinus rhythm. The sites of earliest activation, exit point and activation sequence were mapped for each induced VT. Three different patterns of substrates were determined in 3 patients and located in right ventricular outflow tract, anterior right ventricular wall, and anterolateral right ventricular wall, respectively. Five different clinical VTs (mean CL, 348 ± 65 ms) were induced. Of 5 VTs, three originated from or near the boundary of substrate, and two had a remote origin. One VT conducted through the substrate. Linear ablations were created between the sites of the earliest ventricular activation and the VT exit point, or across the critical isthmus. The five clinical VTs were successfully ablated with a median of 17 radiofrequency applications. One patient was treated with amiodarone for a VT not clinically observed. There were no VT recurrences during 8.6 months of follow-up. Conclusions: Defining the abnormal anatomical VT substrates is useful for understanding the mechanisms of ARVD-VTs and determining an ablation strategy. Linear ablation across a critical isthmus or between the early activation and the exit point can effectively cure these arrhythmias.

Renal Denervation Findings on Cardiac and Renal Fibrosis in Rats with Isoproterenol Induced Cardiomyopathy

Cardio-renal fibrosis plays key roles in heart failure and chronic kidney disease. We sought to determine the effects of renal denervation (RDN) on cardiac and renal fibrosis in rats with isoproterenol induced cardiomyopathy. Sixty male Sprague Dawley rats were randomly assigned to Control (n = 10) and isoproterenol (ISO)-induced cardiomyopathy group (n = 50). At week 5, 31 survival ISO-induced cardiomyopathy rats were randomized to RDN (n = 15) and Sham group (n = 16). Compared with Control group, ejection fraction was decreased, diastolic interventricular septal thickness and left atrial dimension were increased in ISO-induced cardiomyopathy group at 5 week. After 10 weeks, cardio-renal pathophysiologic results demonstrated that the collagen volume fraction of left atrio-ventricular and kidney tissues reduced significantly in RDN group compared with Sham group. Moreover the pro-fibrosis factors (TGF-β1, MMP2 and Collagen I), inflammatory cytokines (CRP and TNF-α), and collagen synthesis biomarkers (PICP, PINP and PIIINP) concentration significantly decreased in RDN group. Compared with Sham group, RDN group showed that release of noradrenaline and aldosterone were reduced, angiotensin-converting enzyme (ACE)/angiotensin II (Ang II)/angiotensin II type-1 receptor (AT1R) axis was downregulated. Meanwhile, angiotensin-converting enzyme 2 (ACE2)/angiotensin-1-7 (Ang-(1-7))/mas receptor (Mas-R) axis was upregulated. RDN inhibits cardio-renal fibrogenesis through multiple pathways, including reducing SNS over-activity, rebalancing RAAS axis.

An algorithm to predict the site of origin of focal atrial tachycardia.

Background: Only a few algorithms for predicting the site of origin of focal atrial tachycardia (AT) have been reported. We aimed to develop a new and more effective algorithm.

Right-Sided Free Wall Accessory Pathway Refractory to Conventional Catheter Ablation: Lessons From 3-Dimensional Electroanatomic Mapping

Right Free Wall Accessory Pathway Ablation. Introduction: The aim of this study was to delineate the electroanatomic substrates of right‐sided free wall (RFW) accessory pathways (APs) that were refractory to conventional catheter ablation utilizing 3‐dimensional (3‐D) mapping.

Beneficial effects of renal denervation on cardiac angiogenesis in rats with prolonged pressure overload.

Renal denervation (RDN) has beneficial effects on cardiac remodelling and function in resistant hypertension. We aimed to investigate the impact of RDN on cardiac angiogenesis during prolonged pressure overload.

Intracoronary delivery of mesenchymal stem cells reduces proarrhythmogenic risks in swine with myocardial infarction

IntroductionThe electrophysiological consequences of mesenchymal stem cell (MSC) therapy in ischemic heart disease have not been fully understood.MethodsSwine myocardial infarction (MI) model by intracoronary balloon occlusion received MSC solution or 0.9% NaCl. Six weeks later, heart rate turbulence (HRT), dispersion of action potential durations (APD) and repolarization time (RT) (APDd and RTd), slope of APD reconstitution curve and programmed electrical stimulation were used to evaluate the ventricular arrhythmic risks.ResultsMSC treatment could significantly ameliorate the abnormal HRT, APD90, APDd, RT and RTd. The slope of APD reconstitution curve in MSC group was higher than control group but lower than MI group. MSC therapy markedly reduced inducible malignant ventricular arrhythmias (VAs), and improved impaired cardiac performances and cardiac fibrosis.ConclusionsThis study provides strong evidence that MSC infusion via intracoronary route does not cause VAs but tends to reduce the risk of malignant VAs.

Renal Denervation Attenuates Multi-Organ Fibrosis and Improves Vascular Remodeling in Rats with Transverse Aortic Constriction Induced Cardiomyopathy

Background/Aims: To investigate the effects of renal denervation (RDN) on multi-organ fibrosis and vascular remodeling in cardiomyopathy. Methods: Thirty-six male Sprague-Dawley rats underwent transverse aortic constriction (TAC). Five weeks later, 28 surviving TAC rats were randomly assigned to three groups: (1) RDN, (2) Sham, (3) Carvedilol. Six male Sham TAC rats served as the Control. Ten weeks after TAC, samples were collected. Results: TAC rats showed an increased diastolic interventricular septal thickness at week 5. At 10 weeks, Masson staining showed that left ventricular and renal glomerular fibrosis were significantly reduced in RDN compared with Sham group. In comparison to Sham group, hepatic perivascular fibrosis was attenuated in both RDN and Carvedilol group, so were the media thickness and the media/lumen of aorta. The plasma levels of B-type natriuretic peptide (BNP), Cystatin C (Cys-C), Alanine Transaminase, angiotensin II (Ang II), transforming growth factor beta 1 (TGF-β1), and malondialdehyde increased, and total superoxide dismutase (T-SOD) decreased in Sham but not in RDN group, compared with Control group. Both RDN and Carvedilol reduced the Cys-C and TGF-β1 levels, and restored T-SOD concentration, compared with Sham group. While only RDN lowered the plasma levels of BNP and Ang II. No significant effects of RDN on blood pressure (BP) and heart rate (HR) were oberved. Conclusions: RDN can attenuate multi-organ fibrosis and improve vascular remodeling independent of BP and HR change in TAC-induced cardiomyopathy. These effects of RDN may be associated with the direct inhibition of renin-angiotensin-aldosterone system and oxidative stress.

Meta-Analysis of Efficacy and Safety of Apixaban in Patients Undergoing Catheter Ablation for Atrial Fibrillation

The efficacy and safety of apixaban in patients undergoing catheter ablation (CA) for atrial fibrillation (AF) are little investigated.

Premature ventricular contractions originating from the right ventricular outflow tract: three-dimensional distribution of the target sites and their electrocardiographic characteristics.

1 The purpose of the present study was to explore the relationship between electrocardiogram (ECG) patterns of right ventricular outflow tract (RVOT) premature ventricular contractions and the three‐dimensional distribution of the target sites. 2 Thirty‐three consecutive patients were included in the study. The target sites were identified by non‐contact mapping and confirmed by successful ablation. The distribution of the target sites in the three‐dimensional reconstructed geometry of the RVOT was classified in three directions: (i) anterior (A)/posterior (P); (ii) free wall (F)/septal (Se); and (iii) superior (Su)/inferior (I). The ECG characteristics were then analysed according to the three‐dimensional distribution of the target sites. 3 The following indices were helpful to identify the position of the target site: (i) QRS duration (≥ 150 msec = F; < 150 msec = Se; P < 0.05); (ii) the R wave pattern in the inferior leads (RR′ or Rr′ = F; R = Se; P < 0.05); (iii) the R wave amplitude in the inferior leads (high = Se; low = F; P < 0.05); (iv) the initial r wave width in lead V1 (wide = F; narrow = Se; P < 0.05); (v) the QS wave amplitude in aVR and aVL (if aVR < aVL, A; if aVR ≥ aVL, P; P < 0.05); and (vi) the initial r wave amplitude in lead V1 and V2 (if V1 ≥ 0.15 mV and V2 ≥ 0.3 mV, Su; if V1 < 0.15 mV or V2 < 0.3 mV, I; P < 0.05). 4 In conclusoin, the ECG characteristics were associated with target site locations in all three directions.