Adenosine monophosphate-regulated protein kinase inhibition modulates electrophysiological characteristics and calcium homeostasis of rabbit right ventricular outflow tract.

Background: Metabolic stress predisposes to ventricular arrhythmias and sudden cardiac death. Right ventricular outflow tract (RVOT) is the common origin of ventricular arrhythmias. Adenosine monophosphate-regulated protein kinase (AMPK) activation is an important compensatory mechanism for cardiac remodeling during metabolic stress.

Fibroblast Growth Factor 1 Reduces Pulmonary Vein and Atrium Arrhythmogenesis Modification of Oxidative Stress and Sodium/Calcium Homeostasis.

Rationale: Atrial fibrillation is a critical health burden. Targeting calcium (Ca) dysregulation and oxidative stress are potential upstream therapeutic strategies. Fibroblast growth factor (FGF) 1 can modulate Ca homeostasis and has antioxidant activity.

Vascular endothelial growth factor modulates pulmonary vein arrhythmogenesis via vascular endothelial growth factor receptor 1/NOS pathway.

Atrial fibrillation (AF) is a common form of arrhythmia with serious public health impacts, but its underlying mechanisms are not yet fully understood. Vascular endothelial growth factor (VEGF) is highly expressed in the atrium of patients with AF, but whether VEGF affects AF pathogenesis remains unclear. Pulmonary veins (PVs) are important sources for the genesis of atrial tachycardia or AF.

Trastuzumab increases pulmonary vein arrhythmogenesis through modulating pulmonary vein electrical and conduction properties via phosphatidylinositol 3-kinase signaling.

Objectives: Drug-induced atrial fibrillation (AF) is considered an adverse effect of chemotherapeutic drugs. AF is a crucial risk factor for stroke, heart failure, myocardial infarction, and mortality. Pulmonary veins (PVs) are considered triggers inducing AF, and the sinoatrial node (SAN) may modulate PV activity and participate in AF genesis.

Various subtypes of phosphodiesterase inhibitors differentially regulate pulmonary vein and sinoatrial node electrical activities.

Phosphodiesterase (PDE)3-5 are expressed in cardiac tissue and play critical roles in the pathogenesis of heart failure and atrial fibrillation. PDE inhibitors are widely used in the clinic, but their effects on the electrical activity of the heart are not well understood. The aim of the present study was to examine the effects of various PDE inhibitors on spontaneous cardiac activity and compare those effects between sinoatrial nodes (SANs) and pulmonary veins (PVs).

Effects of ANP on pulmonary vein electrophysiology, Ca homeostasis and adrenergic arrhythmogenesis via PKA.

Atrial fibrillation (AF) is the most common form of arrhythmia and increases the risk of stroke and heart failure (HF). Pulmonary veins (PVs) are important sources of triggers that generate AF, and calcium (Ca ) overload participates in PV arrhythmogenesis. Neurohormonal activation is an important cause of AF.

Evolution and diversity of the courtship repertoire in the Drosophila montium species group (Diptera: Drosophilidae).

Changes in elements of courtship behaviour can influence sexual isolation between species. Large-scale analyses of changes, including loss and gain of courtship elements, across a relatively complete phylogenetic group are rare but needed to understand the significance of such changes, for example whether the gain and loss of courtship elements are essentially arbitrary or equally reversible. In most species of Drosophila, courtship, including singing, mainly occurs before mounting as premounting courtship.

Factor Xa inhibitors differently modulate electrical activities in pulmonary veins and the sinoatrial node.

Factor Xa inhibitors reduce stroke in patients with atrial fibrillation. Pulmonary veins (PVs) and the sinoatrial node (SAN) are crucial for genesis of atrial fibrillation. However, the electrophysiological effects of factor Xa inhibitors (edoxaban and rivaroxaban) on PVs and the SAN remain unclear.

Angiotensin 1-7 modulates electrophysiological characteristics and calcium homoeostasis in pulmonary veins cardiomyocytes via MAS/PI3K/eNOS signalling pathway.

Background: Atrial fibrillation (AF) is the most common sustained arrhythmia, and pulmonary veins (PVs) play a critical role in triggering AF. Angiotensin (Ang)-(1-7) regulates calcium (Ca ) homoeostasis and also plays a critical role in cardiovascular pathophysiology. However, the role of Ang-(1-7) in PV arrhythmogenesis remains unclear.

Mitochondrial dysfunction on sinoatrial node and pulmonary vein electrophysiological activities.

Atrial fibrillation (AF) is associated with mitochondrial dysfunction. Sinoatrial node (SAN) dysfunction increases arrhythmogenesis of pulmonary veins (PVs), which is the most important trigger of AF; however, it is not clear whether mitochondrial dysfunction differentially regulates electrical activity of SANs and PVs. In the present study, conventional microelectrodes were used to record the action potentials (APs) in isolated rabbit PVs, SANs, left atrium (LA) and right atrium (RA) before and after application of trifluorocarbonylcyanide phenylhydrazone (FCCP; a mitochondrial uncoupling agent) at 10, 100 and 300 nM.

Discrepant effects of heart failure on electrophysiological property in right ventricular outflow tract and left ventricular outflow tract cardiomyocytes.

Ventricular arrhythmias commonly arise from the right (RVOT) and left ventricular outflow tracts (LVOT) in patients without structural heart disease. Heart failure (HF) significantly increases the risk of ventricular arrhythmias. The regional differences and how HF affects the electrophysiological characteristics of RVOT and LVOT cardiomyocytes remain unclear.

2016 Guidelines of the Taiwan Heart Rhythm Society and the Taiwan Society of Cardiology for the management of atrial fibrillation.

Atrial fibrillation (AF) is the most common sustained arrhythmia. Both the incidence and prevalence of AF are increasing, and the burden of AF is becoming huge. Many innovative advances have emerged in the past decade for the diagnosis and management of AF, including a new scoring system for the prediction of stroke and bleeding events, the introduction of non-vitamin K antagonist oral anticoagulants and their special benefits in Asians, new rhythm- and rate-control concepts, optimal endpoints of rate control, upstream therapy, life-style modification to prevent AF recurrence, and new ablation techniques.

Gap junction modifiers regulate electrical activities of the sinoatrial node and pulmonary vein: Therapeutic implications in atrial arrhythmogenesis.

Background: Gap junction (GJ) dysfunctions predispose cardiac tissues to various arrhythmias. Sinoatrial node (SAN) and pulmonary veins (PVs) are closely related atrial dysrhythmia. This study evaluated whether GJ modifications modulate SAN and PVs electrical activities.

Electrolyte disturbances differentially regulate sinoatrial node and pulmonary vein electrical activity: A contribution to hypokalemia- or hyponatremia-induced atrial fibrillation.

Background: Hypokalemia and hyponatremia increase the occurrence of atrial fibrillation. Sinoatrial nodes (SANs) and pulmonary veins (PVs) play a critical role in the pathophysiology of atrial fibrillation.

Objective: The purpose of this study was to evaluate whether electrolyte disturbances with low concentrations of potassium ([K(+)]) or sodium ([Na(+)]) modulate SAN and PV electrical activity and arrhythmogenesis, and to investigate potential underlying mechanisms.

Selective and non-selective non-steroidal anti-inflammatory drugs differentially regulate pulmonary vein and atrial arrhythmogenesis.

Background: Non-steroidal anti-inflammatory drugs (NSAIDs) increase the risk of atrial fibrillation (AF). This study investigated whether selective and non-selective NSAIDs differentially regulate the arrhythmogenesis of pulmonary veins and atria.

Methods: Conventional microelectrodes were used to record action potentials (APs) in isolated rabbit PVs, sinoatrial node (SAN), left atrium (LA), and right atrium (RA) preparations before and after celecoxib or indomethacin administration.

A monounsaturated fatty acid (oleic acid) modulates electrical activity in atrial myocytes with calcium and sodium dysregulation.

Background: Obesity and metabolic syndrome are important risk factors for atrial fibrillation. High plasma concentrations of monounsaturated fatty acids, including oleic acid (OLA), are frequently noted in obese individuals and patients with metabolic syndrome. However, it is not clear whether monounsaturated fatty acids (MUFAs) can directly modulate the electrophysiological characteristics of atrial myocytes.

Sinoatrial node electrical activity modulates pulmonary vein arrhythmogenesis.

Background: Sinoatrial node (SAN) dysfunction increases the occurrences of atrial fibrillation (AF). The pulmonary veins (PVs) play a critical role in the pathophysiology of AF. The purpose of this study was to evaluate whether SAN electrical activity can modulate PV arrhythmogenesis.

Courtship patterns in the Drosophila montium species subgroup: repeated loss of precopulatory courtship?

During precopulatory courtship, male Drosophila typically produce wing vibration to generate species-specific songs before mounting females. Three species in the lini clade of the montium species subgroup have been found to produce species-specific sine song only after mounting and during copulation. Here we investigated and analyzed the courtship behavior of 29 species in the montium subgroup from video and song recordings and measured the duration of wing vibration.

Immune-related transcriptome of Coptotermes formosanus Shiraki workers: the defense mechanism.

Formosan subterranean termites, Coptotermes formosanus Shiraki, live socially in microbial-rich habitats. To understand the molecular mechanism by which termites combat pathogenic microbes, a full-length normalized cDNA library and four Suppression Subtractive Hybridization (SSH) libraries were constructed from termite workers infected with entomopathogenic fungi (Metarhizium anisopliae and Beauveria bassiana), Gram-positive Bacillus thuringiensis and Gram-negative Escherichia coli, and the libraries were analyzed. From the high quality normalized cDNA library, 439 immune-related sequences were identified.

Apelin regulates the electrophysiological characteristics of atrial myocytes.

Background: Apelin, a potential agent for treating heart failure, has various ionic effects on ventricular myocytes. However, the effects of apelin on the atrium are not clear. The purpose of this study was to investigate the acute effects of apelin on the electrophysiological characteristics of atrial myocytes.

Novel assessment of temporal variation in fractionated electrograms using histogram analysis of local fractionation interval in patients with persistent atrial fibrillation.

Background: The characteristics of atrial electrograms associated with atrial fibrillation (AF) termination are controversial. We investigated the electrogram characteristics that indicate procedural AF termination during continuous complex fractionated electrogram ablation.

Methods And Results: Fifty-two consecutive patients with persistent AF (47 men; aged 54 ± 9 years), who underwent electrogram-based catheter ablation in the left atrium and coronary sinus after pulmonary vein isolation, were enrolled.

Long-term outcome of catheter ablation in patients with atrial fibrillation originating from the superior vena cava.

Unlabelled: Long-Term Outcome of SVC AF Ablation.

Introduction: Data of the long-term clinical outcome after superior vena cava (SVC) isolation are limited. We aimed to evaluate the long-term outcome in patients with atrial fibrillation (AF) who had triggers originating from the SVC and received catheter ablation of AF.

Long-term follow-up in patients with arrhythmogenic right ventricular cardiomyopathy.

Introduction: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a major cause of sudden cardiac death due to tachyarrhythmias. The purpose of this study was to investigate the long-term prognosis in patients with ARVC and the incidence of rapid ventricular arrhythmias during follow-up.

Methods: Thirty ARVC patients (19 male, 63.

ATX-II-induced pulmonary vein arrhythmogenesis related to atrial fibrillation and long QT syndrome.

Background: Long QT syndrome (LQTS) is associated with a high incidence of atrial fibrillation (AF), but the underlying mechanisms are unclear. Pulmonary veins (PVs) play a critical role in AF genesis. Type 3 LQTS increases late sodium current (I(Na,L) ), which may increase PV arrhythmogenesis and AF.