Jiangang Zou

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.nMethods 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.nConclusions: 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.

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.

Short-term normalization of ventricular repolarization by transcatheter ablation in a patient with suspected Brugada Syndrome

We report a 30xa0year old male without structural heart disease who presented with recurrent nocturnal syncope and aborted sudden cardiac death. 12-lead ECG showed elevated ST in inferior leads and short coupled premature ventricular complexes (PVCs). Propafenone challenge suggested a diagnosis of an atypical Brugada syndrome. Two morphological types of PVCs and ventricular fibrillation (VF) were induced during propafenone challenge test. He underwent two ablation procedures in right ventricular inflow tract and left ventricular post-inferior septum region by pace-mapping, respectively. After ablation, VF could not be induced and the elevated ST segments normalized. Two subsequent propafenone challenge tests were also negative. Nonetheless, elevated ST segments and PVCs reappeared by 1xa0month follow-up. An implantable defibrillator was recommended, but the patient declined for financial reasons. Unfortunately, he suffered a sudden cardiac death at home 10xa0weeks post-ablation. These findings suggest that short-term normalization of ventricular repolarization possibly due to radiofrequency ablation may occur in Brugada syndrome. However, the transient nature of this finding suggests that it is not a reliable indicator of protection against sudden cardiac death.

Tpeak-Tend interval as a new risk factor for arrhythmic event in patient with Brugada syndrome

Abstract Objective To evaluate Tpeak-Tend(Tp-e) interval in surface standard ECG as a new risk factor for arrhythmic event in patient with Brugada syndrome. Methods 23 male patients with Brugada syndrome and 20 male patients with paroxysmal supraventricular tachycardia(PSVT) as the control group were investigated in this study. Tp-e interval in surface standard ECG was compared between BrS and PSVT patients. Results Tp-e interval in BrS patients was significantly longer than that in PSVT patients (109.57 ± 2.86 ms vs. 88.50 ± 3.08ms, P P P P > 0.05). Conclusion The prolongation of Tp-e interval could serve as a new noninvasive event predictor for arrhyth- mic events in patients with Brugada syndrome.

Predictors of Post Coronary Artery Bypass Grafting Atrial Fibrillation

Objective: To investigate the incidence and relative risk factors of post coronary artery bypass grafting(post-CABG) atrial fibrillation (AF). Methods: 312 patients with CABG were reviewed and divided into an AF group and a non-AF group. Statistical analysis was used to compare the data between the two groups and screen for risk factors of post-CABG AF. Results: 103/312 (33.01%) patients developed post-CABG AF. Univariate analysis showed that patients in AF group compared with those in non-AF group were more likely to have advanced age (≥70 years), early postoperative withdrawal of β-blockers, hypertension, left atrial enlargement (≥40 mm), a history of AF, prolonged p-wave duration (≥120 ms) and increased number of grafts (≥3). Multivariate logistic regression analysis showed that advanced age (≥70 years), early postoperative withdrawal of β-blockers, hypertension, left atrial enlargement (≥40 mm) and a history of AF were highly related to post-CABG AF. Conclusion: The incidence of AF in patients following CABG was 33.01% in this study. Advanced age, early postoperative withdrawal of β-blockers, hypertension, left atrial enlargement and a history of AF were independent risk factors of post-CABG AF.

Termination of polymorphic ventricular tachycardia storm by catheter ablation in a patient with cardiomyopathy induced by incessant idiopathic left ventricular tachycardia.

We detail findings in a patient with incessant idiopathic left ventricular tachycardia (ILVT), induced cardiomyopathy, and an “electrical storm” consisting of recurrent polymorphic ventricular tachycardia (PVT). Catheter ablation not only eradicated the ILVT, but also additionally suppressed recurrent PVT. These findings suggest that the recurrent PVT storm in this patient related to long‐standing tachycardia‐induced cardiac electrical remodeling that led to QT prolongation.

Narrow QRS Tachycardia with Ventriculoatrial Dissociation Mediated by a Left Fasciculoventricular Fiber

A 30-year-old man presented with narrow QRS tachycardia. The intracardiac electrocardiogram showed an atrial-HIS (AH) interval of 75 msec and a HIS-ventricular (HV) interval of 44 msec during baseline. Atrial incremental pacing revealed HV shortening, with apparent incomplete right bundle branch block (RBBB) morphology without QRS complex axis deviation. The induced tachycardia exhibited several QRS morphologies: a narrow QRS, complete RBBB and complete left bundle branch block (LBBB) morphology. Spontaneous conversion of the QRS pattern from wide to narrow was observed. The cycle length of the tachycardia was significantly shortened (from 316 to 272 ms) from LBBB morphology to narrow QRS complex. The atrial activation was dissociated from the ventricular activation during all tachycardias. Each QRS complex during tachycardia was preceded by a HIS deflection and HV interval was 35 ms, which was shorter than that of sinus rhythm. HIS deflection was earlier than right bundle potential during all kinds of tachycardia. This tachycardia is most likely mediated by a left fasciculoventricular fiber which connects the HIS bundle below the atrioventricular node to the myocardial tissue of the left ventricle. The HIS-Purkinje system is used as an antegrade conduction limb and the fasciculoventricular fiber as a retrograde limb in the tachycardia circuit.