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.

A Deep Learning-Enabled Electrocardiogram Model for the Identification of a Rare Inherited Arrhythmia: Brugada Syndrome.

Background: Brugada syndrome is a major cause of sudden cardiac death in young people and has distinctive electrocardiographic (ECG) features. We aimed to develop a deep learning-enabled ECG model for automatic screening for Brugada syndrome to identify these patients at an early point in time, thus allowing for life-saving therapy.

Methods: A total of 276 ECGs with a type 1 Brugada ECG pattern (276 type 1 Brugada ECGs and another randomly retrieved 276 non-Brugada type ECGs for 1:1 allocation) were extracted from the hospital-based ECG database for a 2-stage analysis with a deep learning model.

RR interval variability in the evaluation of ventricular tachycardia and effects of implantable cardioverter defibrillator therapy.

Background: An implantable cardioverter defibrillator (ICD) is the most reliable therapeutic device for preventing sudden cardiac death in patients with sustained ventricular tachycardia (VT). Regarding its effectiveness, targeted VT is defined based on the tachyarrhythmia cycle length. However, variations in RR interval variability of VTs may occur.

Deep Sedation with Intravenous Anesthesia Is Associated with Outcome in Patients Undergoing Cryoablation for Paroxysmal Atrial Fibrillation.

Whether deep sedation with intravenous anesthesia will affect the recurrence after cryoballoon ablation (CBA) of paroxysmal atrial fibrillation (AF) is yet to be examined. Thus, in this study, we hypothesize that there is difference in terms of the recurrence between local anesthesia and deep sedation with intravenous anesthesia after an index ablation procedure.In total, 109 patients were enrolled and received CBA, of which 68 (58.

Mechanism of angiotensin receptor-neprilysin inhibitor in suppression of ventricular arrhythmia.

Background: The mechanisms underlying angiotensin receptor-neprilysin inhibitor (ARNi) suppression of ventricular arrhythmia (VA) are unclear. This study aimed to investigate the mechanism of ARNi-related suppression of VA in a heart failure (HF) model.

Methods: New Zealand white rabbits (n = 6 per group) were assigned to normal, HF [4 weeks of left ascending artery (LAD) ligation], angiotensin receptor blocker (ARB, valsartan at 27 mg/kg/day for 3 weeks after 1 week of LAD ligation), and ARNi (sacubitril at 34 mg/kg/day and valsartan at 27 mg/kg/day for 3 weeks after 1 week of LAD ligation) groups.

Proinflammatory Cytokine Modulates Intracellular Calcium Handling and Enhances Ventricular Arrhythmia Susceptibility.

The mechanism of Interleukin-17 (IL-17) induced ventricular arrhythmia (VA) remains unclear. This study aimed to investigate the effect of intracellular calcium (Ca) handling and VA susceptibility by IL-17. The electrophysiological properties of isolated perfused rabbit hearts under IL-17 (20 ng/ml, = 6) and the IL-17 with neutralizer (0.

Diabetes and Endocrine Disorders (Hyperthyroidism/Hypothyroidism) as Risk Factors for Atrial Fibrillation.

Risk factors including cardiometabolic and endocrine disorders have a significant impact on atrial remodeling causing atrial fibrillation (AF). Diabetes mellitus and hyperthyroidism are strong independent risk factors for AF and worsen outcomes of rhythm control strategies. An early diagnosis and intervention for these risk factors combined with rhythm control strategies may improve the overall cardiovascular mortality and morbidity.

ZFHX3 knockdown dysregulates mitochondrial adaptations to tachypacing in atrial myocytes through enhanced oxidative stress and calcium overload.

Aim: To investigate the role of zinc finger homeobox 3 gene (ZFHX3) in tachypacing-induced mitochondrial dysfunction and explore its molecular mechanisms and potential as a therapeutic target in atrial fibrillation (AF).

Methods: Through a bioluminescent assay, a patch clamp, confocal fluorescence and fluorescence microscopy, microplate enzyme activity assays and Western blotting, we studied ATP and ADP production, mitochondrial electron transfer chain complex activities, ATP-sensitive potassium channels (I ), mitochondrial oxidative stress, Ca content, and protein expression in control and ZFHX3 knockdown (KD) HL-1 cells subjected to 1 and 5-Hz pacing for 24 hours.

Results: Compared with 1-Hz pacing, 5-Hz pacing increased ATP and ADP production, I , phosphorylated adenosine monophosphate-activated protein kinase and inositol 1,4,5-triphosphate (IP ) receptor (IP R) protein expression.

Rhodiola crenulata reduces ventricular arrhythmia through mitigating the activation of IL-17 and inhibiting the MAPK signaling pathway.

Purpose: Ventricular arrhythmia (VA) is related to inflammatory activity. Rhodiola crenulate (RC) and its main active component, salidroside, have been reported as anti-inflammatory agents. The aim of this study was to demonstrate the effect of RC and salidroside in preventing VA via the inhibition of IL-17 in an ischemic heart failure (HF) model.

Concurrent increases in post-pacing action potential duration and contractility predict occurrence of ventricular arrhythmia.

Excitation-contraction coupling from the integration of action potential duration (APD) and muscle contractility plays an important role in arrhythmogenesis. We aimed to determine whether distinctive excitation-contraction coupling contributes to the genesis of ventricular tachycardias (VTs). Action potential (AP) and mechanical activity were simultaneously recorded under electrical pacing (cycle lengths from 1000 to 100 ms) in the tissue model created from isolated rabbit right ventricular outflow tracts treated with NS 5806 (10 μM, transient outward potassium current enhancer), pinacidil (2 μM, ATP-sensitive potassium channel opener), and pilsicainide (5 μM, sodium channel blocker).

Resistin as a Biomarker for the Prediction of Left Atrial Substrate and Recurrence in Patients with Drug-Refractory Atrial Fibrillation Undergoing Catheter Ablation.

Resistin is an adipocytokine that is abundantly secreted from lipid cells and is related to the inflammatory process and cardiometabolic diseases. This study aimed to examine the role of resistin on inflammation and its effect on the clinical outcome of patients with atrial fibrillation (AF) following catheter ablation.A total of 108 patients (56.

The AMP-activated protein kinase modulates hypothermia-induced J wave.

Background: The mechanism underlying the occurrence of the J wave in low temperature remains unclear. However, low temperature is associated with metabolic disorder and 5' AMP-activated protein kinase (AMPK), which modulates ionic currents and cardiac metabolism. This study investigated whether AMPK regulation can modulate the occurrence of the J wave at low temperature.

Cryoballoon Ablation for Patients With Paroxysmal Atrial Fibrillation.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in clinical practice and induces cardiac dysfunction and stroke. The development of AF requires a trigger and also an electroanatomic substrate capable of both initiating and perpetuating AF. In the past decade, ectopic beats originating from the pulmonary veins (PV) have been identified as a source of paroxysmal AF.

Catheter Ablation of Paroxysmal Atrial Fibrillation Originating from Non-pulmonary Vein Areas.

Pulmonary veins (PVs) are a major source of ectopic beats that initiate AF. PV isolation from the left atrium is an effective therapy for the majority of paroxysmal AF. However, investigators have reported that ectopy originating from non-PV areas can also initiate AF.

Interleukin-17 enhances cardiac ventricular remodeling via activating MAPK pathway in ischemic heart failure.

Background: We aimed to investigate the impact of interleukin (IL)-17 on ventricular remodeling and the genesis of ventricular arrhythmia (VA) in an ischemic heart failure (HF) model. The expression of the proinflammatory cytokine IL-17 is upregulated during myocardial ischemia and plays a fundamental role in post-infarct inflammation. However, the influence of IL-17 on the genesis of VA has not yet been studied.

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.

Impact of Renal Denervation on Atrial Arrhythmogenic Substrate in Ischemic Model of Heart Failure.

Background: Myocardial infarction increases the risk of heart failure (HF) and atrial fibrillation. Renal denervation (RDN) might suppress the development of atrial remodeling. This study aimed to elucidate the molecular mechanism of RDN in the suppression of atrial fibrillation in a HF model after myocardial infarction.

Risk of Stroke in Patients With Short-Run Atrial Tachyarrhythmia.

Background And Purpose: The risk of stroke in patients with short-run atrial tachyarrhythmia (AT) remains unclear. This study aimed to investigate the relationship between short-run AT and the stroke and the use of the CHADS-VASc score for the risk stratification.

Methods: From the registry of 24-hour Holter monitoring, 5342 subjects without known atrial fibrillation or stroke were enrolled.

Superior Rhythm Discrimination With the SmartShock Technology Algorithm - Results of the Implantable Defibrillator With Enhanced Features and Settings for Reduction of Inaccurate Detection (DEFENSE) Trial.

Background: Shocks delivered by implanted anti-tachyarrhythmia devices, even when appropriate, lower the quality of life and survival. The new SmartShock Technology(SST) discrimination algorithm was developed to prevent the delivery of inappropriate shock. This prospective, multicenter, observational study compared the rate of inaccurate detection of ventricular tachyarrhythmia using the SST vs.

The use of a novel signal analysis to identify the origin of idiopathic right ventricular outflow tract ventricular tachycardia during sinus rhythm: Simultaneous amplitude frequency electrogram transformation mapping.

Introduction: The signal characteristics of intracardiac bipolar electrograms at the origin of idiopathic RVOT-VT during sinus rhythm remain unclear.

Objective: The study sought to develop a novel real-time/online technique, simultaneous amplitude frequency electrogram transformation (SAFE-T), to quantify and localize the diseased ventricular substrate in idiopathic RVOT-VT.

Methods: We retrospectively investigated the intracardiac bipolar recordings in 70 consecutive patients (26% male, mean age 42±12 years) who underwent successful radiofrequency catheter ablation of idiopathic RVOT-VT.

The Different Substrate Characteristics of Arrhythmogenic Triggers in Idiopathic Right Ventricular Outflow Tract Tachycardia and Arrhythmogenic Right Ventricular Dysplasia: New Insight from Noncontact Mapping.

Background: The aim of this study was to investigate the different substrate characteristics of repetitive premature ventricular complexed (PVC) trigger sites by the non-contact mapping (NCM).

Methods: Thirty-five consecutive patients, including 14 with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC) and 21 with idiopathic right ventricular outflow tract tachycardia (RVOT VT), were enrolled for electrophysiological study and catheter ablation guided by the NCM. Substrate and electrogram (Eg) characteristics of the earliest activation (EA) and breakout (BO) sites of PVCs were investigated, and these were confirmed by successful PVC elimination.

Resveratrol, a red wine antioxidant, reduces atrial fibrillation susceptibility in the failing heart by PI3K/AKT/eNOS signaling pathway activation.

Background: Resveratrol has shown benefits in reducing ventricular remodeling and arrhythmias.

Objective: This study aimed to assess the therapeutic efficacy of resveratrol in reducing atrial fibrillation (AF) in a heart failure (HF) model and to explore the underlying mechanisms.

Methods: HF rabbits were created 4 weeks after undergoing coronary ligation.

[Reconstruction of the posterior mitral annulus using a crescent-shaped collar; a novel technique for mitral valve replacement in the severely calcified annulus; report of a case].

A 74-year-old female who had been on hemodialysis for 4 years developed congestive heart failure. Severe mitral valve stenosis and tricuspid regurgitation were thought to be causes of her heart failure. She underwent a replacement of severely calcified mitral valve and an annuloplasty of tricuspid valve.