[Characteristics of electrophysiology and effects of ouabain on transient outward potassium current and L-type calcium current of left atrium posterior wall in rabbits].

Objective: To investigate the properties of electrophysiology and effects of ouabain upon transient outward potassium current (I(to)) and L-type calcium current (I(Ca-L)) of left atrium posterior wall (LAPW) and left atrium appendage tissue (LAA)in rabbit so as to provide the scientific explanations that LAPW and ouabain can enhance atrial fibrillation (AF) vulnerability through increasing electrophysiological heterogeneity and electrical remodeling of different regions of left atrium in rabbits.

Methods: Atrial myocytes from LAPWs and LAAs of rabbits on an in vitro heart perfusion system were obtained by enzymatic dissociation. The whole-cell patch-clamp technique was used to assess the effects of ouabain upon I(to) and I(Ca-L).

[Effects of NADPH oxidase inhibition on cardiac function and myocardial calcium regulatory proteins in rabbits with heart failure].

Objective: To investigate the effects of NADPH oxidase inhibition on cardiac function and myocardial calcium regulatory proteins mRNA expressions in rabbits with heart failure (HF).

Methods: HF was induced by experimental aortic insufficiency and abdominal aortic constriction, HF animals were treated with oral apocynin (15 mg/d), a NADPH oxidase inhibitor or equal dose placebo. Eight weeks later, cardiac function was measured by echocardiography.

A single amino acid change in Ca(v)1.2 channels eliminates the permeation and gating differences between Ca(2+) and Ba(2+).

Glutamate scanning mutagenesis was used to assess the role of the calcicludine binding segment in regulating channel permeation and gating using both Ca(2+) and Ba(2+) as charge carriers. As expected, wild-type Ca(V)1.2 channels had a Ba(2+) conductance ~2x that in Ca(2+) (G(Ba)/G(Ca) = 2) and activation was ~10 mV more positive in Ca(2+) vs.

Depressive symptoms and risk factors in Chinese patients with premature ventricular contractions without structural heart disease.

Hypothesis: Our objective was to study depressive symptoms and potential risk factors in Chinese persons with premature ventricular contractions (PVCs) without structural heart disease.

Methods: The Zung self-rating depression scale (ZSDS) was used to assess depressive symptoms. Correlations between depressive symptoms and sociodemographic and medical factors were analyzed by logistic regression.

[Curcumin attenuates left ventricular dysfunction and remodeling in rabbits with chronic heart failure.].

Objective: To investigate the effects of Curcumin on rabbits with chronic heart failure.

Methods: Heart failure was induced by combined aortic regurgitation and aortic stenosis in 20 New Zealand rabbits and treated with placebo (HF, n = 10) and Curcumin (Cur, 100 mgxkg(-1)xd(-1), n = 10) for 8 weeks, 10 sham operated rabbits served as controls (Con). Echocardiography was performed in all rabbits at baseline and 8 weeks later.

Ghrelin inhibits post-infarct myocardial remodeling and improves cardiac function through anti-inflammation effect.

Ghrelin is a novel growth hormone-releasing peptide, which has been shown to exert beneficial cardiac effects on chronic heart failure (CHF) recently. In this study, we attempted to investigate the mechanisms for the effect of ghrelin on ventricular remodeling following acute myocardial infarction (MI). Ligation of a coronary artery was used to create an MI in rats.

[Effects of BmKIM on sodium current of isolated cardiomyocytes, transmembrane action potential and aconitine induced arrhythmia in vivo in rabbits].

Objective: To investigate the effects of recombinant BmKIM (poly-peptide derived from Asian Scorpion Buthus martensi Karsch) on the sodium current (I(Na)) of isolated ventricular myocytes, transmembrane action potential and aconitine induced arrhythmia in vivo in rabbits.

Methods: Ventricular myocytes were enzymatically dissociated from adult rabbits. Whole-cell patch-clamp technique was used to record voltage-dependent I(Na).

Changes in atrial effective refractory period and I(KACh) after vagal stimulation plus rapid pacing in the pulmonary vein.

Introduction And Objectives: Recent studies have shown that rapid atrial pacing causes atrial electrical remodeling. However, the influence of the vagus nerve on atrial electrical remodeling is not clear.

Methods: This study involved 24 dogs divided into three groups.

A novel peptide ghrelin inhibits neural remodeling after myocardial infarction in rats.

Ghrelin is a newly discovered peptide as an endogenous ligand for the growth hormone secretagogue receptor, and has been demonstrated to exert beneficial effect in the cardiovascular system. In the present study, we investigated whether ghrelin administration could inhibit cardiac neural remodeling and sympathetic hyperinnervation after myocardial infarction. Sprague-Dawley rats underwent coronary ligation to induce myocardial infarction and receiving ghrelin chronically (100 microg/kg s.

Same ablation may be used for frequent premature ventricular contractions and supraventricular tachycardia.

Radiofrequency catheter ablation (RFCA) has been increasingly used for the treatment of various kinds of cardiac arrhythmias over the past 20 years. RFCA of symptomatic premature ventricular contractions (PVCs) has been reported to be a safe and effective treatment option and may be considered in patients with extremely symptomatic or incapacitating cases who do not respond to medications. Long-term prognosis in patients with truly idiopathic PVCs is excellent, despite frequent recurrences of tachycardia.

[Circumferential pulmonary vein with additional linear ablation for persistent and permanent atrial].

Objective: To investigate the safety and efficacy of circumferential pulmonary vein with additional linear ablation in treatment of persistent and permanent atrial fibrillation (AF), and to identify possible predictors of recurrence of AF.

Methods: The clinical data of 127 patients with persistent and permanent AF who had undergone circumferential pulmonary vein with additional linear ablation from January 2006 to December 2006 in multiple electrophysiological centers were collected, success rate and recurrence rate, cardiac function and atrial arrhythmias after ablation, and complications were analyzed. The relationship between the recurrent AF and clinical and echocardiographic variables was investigated.

Relationship between autonomic innervation in crista terminalis and atrial arrhythmia.

Background: The crista terminalis (CT) is known to initiate and maintain atrial arrhythmia, and is affected by autonomic tone, but the underlying mechanisms are poorly understood. This study sought to study the relation between autonomic innervation in CT and atrial arrhythmia.

Methods: Thirty adult canines were used in the present study.

Acetylcholine-regulated K+ current remodelling in the atrium after myocardial infarction and valsartan administration.

Background: Atrial fibrillation (AF) is a common complication of myocardial infarction (MI). Angiotensin II receptor antagonists prevent the promotion and propagation of AF. However, the activation of the acetylcholine-regulated K(+) current (I(K,ACh)) in the atrium after MI and the effect of valsartan on I(K,ACh) are less understood.

Sinus node, phrenic nerve and electrical connections between superior vena cava and right atrium: lessons learned from a prospective study.

Background: When performing superior vena cava isolation, the major concerns are inadvertent ablation on sinus node and right phrenic nerve. However, little is known about the spatial relationship of electrical connections between superior vena cava and right atrium with the sinus node and phrenic nerve locations among individual patients.

Methods: We studied 87 patients (male/female 60/27, mean age of (51 +/- 9) years) with atrial fibrillation.

New access for radiofrequency catheter ablation of left-sided atrioventricular accessory pathways: safety and efficacy of the transradial approach.

Background: The safety and efficacy of the transradial approach for radiofrequency catheter ablation (RFCA) of left-sided atrioventricular accessory pathways (APs) was evaluated in the present study.

Methods And Results: Included were 40 consecutive patients with type A Wolff-Parkinson-White (WPW) syndrome who underwent RFCA via the radial artery route, and 30 patients with type A WPW syndrome who underwent RFCA via the transfemoral approach (controls) were retrospectively chosen for control. All 45 APs in the 40 patients were successfully ablated: 35 APs were successfully blocked with 1 ablation attempt, and the other 10 APs were ablated after 2-4 attempts.

Novel thermosensitive hydrogel injection inhibits post-infarct ventricle remodelling.

Aims: Myocardial infarction (MI) remains the commonest cause of cardiac-related death throughout the world. Adverse cardiac remodelling and progressive heart failure after MI are associated with excessive and continuous damage of the extracellular matrix (ECM). In this study, we hypothesized that implantation of hydrogel into infarcted myocardium could replace the damaged ECM, thicken the infarcted wall, and inhibit cardiac remodelling.

Oxidative stress: a possible pathogenesis of atrial fibrillation.

Atrial fibrillation (AF) is the most commonly sustained arrhythmia in clinical practice. Despite the extensive studies, the pathophysiology of AF, however, remains incompletely understood. Studies have demonstrated that oxidative stress may be involved in cardiac structural and electrical remodeling.

[Comparison of coronary plaque composition between patients with acute coronary syndrome and stable coronary artery disease].

Objective: The purpose of the present study was to compare the plaque composition between patients with acute coronary syndrome (ACS) and stable coronary artery disease (SCAD) by intravascular ultrasound virtual histological analysis.

Methods: Two hundred and ten patients were divided into ACS group (n = 131, 188 diseased vessels) and SCAD group (n = 79, 158 diseased vessels). A total of 346 de novo lesions with > 50% stenosis in native coronary arteries with diameters > 2.

[Effects of antiarrhythmic drug use on atrial fibrillation recurrence in atrial fibrillation patients post circumferential pulmonary vein ablation].

Objective: This prospective and randomize-controlled trial was designed to investigate the effects of antiarrhythmic drug use (AADs) on atrial fibrillation (AF) recurrence in atrial fibrillation patients post circumferential pulmonary vein ablation (CAPV).

Methods: Seventy-four consecutive AF patients underwent CAPV (41 paroxysmal and 33 drug refractory AF) were randomly assigned to receive placebo (Group A) or AADs (Group B) for 3 months. Monthly standard electrocardiograms (ECG) and Holter monitoring were performed to assess AF recurrences during 17 - 28 months follow-up.

[Association between inflammatory cytokine CD40 gene polymorphism and risk of acute coronary syndrome].

Objective: To investigate the expression levels of CD40, sCD40L, hs-CRP, WBC in acute coronary syndrome (ACS) patients and the association between CD40-1C/T single nucleotide polymorphism and risk of ACS in Han Chinese, moreover, the regulatory effects of IFN-gamma and fluvastatin on the expression of CD40 in peripheral blood mononuclear cell (PBMNC) were also observed.

Methods: (1) 160 ACS patients and 92 control patients diagnosed by coronary angiography were recruited. Enzyme linked immunosorbent assay, particle enhanced immunoturbidimetric assay, flow cytometry were used to detect the levels of soluble CD40L, hs-CRP, and WBC count.

Effect of transplanted mesenchymal stem cells from rats of different ages on the improvement of heart function after acute myocardial infarction.

Background: Mesenchymal stem cells (MSCs) transplantation is of therapeutic potential after ischemic injury in both experimental and clinical studies. Clinically, elderly patients are more vulnerable to acute myocardial infarction (AMI). But little is known about the characteristics of young donor-derived MSCs transplanted to old patients with AMI.

[Effects of sympathetic nerve stimulation on connexin43 and ventricular arrhythmias during acute myocardial ischemia: experiment with rats].

Objective: To investigate the effects of sympathetic nerve stimulation (SNS) on connexin43 (Cx43) and ventricular arrhythmias during acute myocardial ischemia (MI).

Methods: Ninety five Wistar rats were randomly divided into four groups: MI group (n=25), undergoing: ligation of the anterior descending coronary; MII-SNS group (n=25); undergoing electric stimulation of sympathetic nerve since the beginning of ligation of the anterior descending coronary and lasting till 30 min after the ligation, sympathetic nerve stimulation preconditioning + myocardial ischemia (pSNS-MI) group (n=25), undergoing electric stimulation of sympathetic nerve since the beginning of ligation of the anterior descending coronary that ended just after the ligation; and sham operation (SO) group (n=20), without coronary ligation. Ventricular arrhythmias were monitored by electrocardiography.

The influence of carvedilol on atrial connexin 40 after myocardial infarction.

Objective: The purpose of the present study was to study the influence of left ventricular myocardial infarction on gap junction protein connexin 40 in the atria, and to observe the intervention function of carvedilol as an adrenergic receptor blocker.

Methods And Results: Thirty New Zealand rabbits were randomly divided into three experimental groups: myocardial infarction, carvedilol and control groups. The left anterior descending coronary artery was ligated in animals in the myocardial infarction group; in the control animals no artery was ligated.

Injection of a novel synthetic hydrogel preserves left ventricle function after myocardial infarction.

Myocardial infarction (MI) and the subsequent heart failure remain one of the leading causes of morbidity and mortality world wide. A number of studies have demonstrated that bioderived materials improve cardiac function after implantation because of their angiogenic potential. In this study, we hypothesized that injection of biomaterials into infarcted myocardium can preserve left ventricular (LV) function through its prevention of paradoxical systolic bulging.

M2 and M3-muscarinic acetylcholine receptors remodelling in patients with a dilated atrium.

Background: Studies have shown that autonomic tone plays an important role in the pathogenesis of atrial fibrillation (AF) and remodelling of I(K, ACh) in chronic AF serves as a compensatory mechanism for the AF. The relation between atrial size and AF has been established. We investigated the remodelling of muscarinic receptors in patients with dilated atrium and assessed the relationship between the muscarinic receptor remodelling and the dilated atrium.