Improved left atrial catheterization efficiency and consistency using a novel steerable transseptal puncture sheath.

Background: While steerable sheaths are widely used to improve catheter stability and contact force during radiofrequency (RF) catheter ablation in patients with atrial fibrillation (AF), steerable sheaths are less commonly used during transseptal puncture. This study evaluated whether left atrial catheterization efficiency can be improved using the VersaCross combined steerable sheath and transseptal system compared to previous standard workflow.

Methods: This study retrospectively analyzed AF ablation performed using the VersaCross Workflow consisting of VersaCross steerable sheath and RF wire for transseptal puncture and catheter ablation (VCW) to the standard workflow using a fixed curve sheath with RF needle followed by exchange for an Agilis steerable sheath for catheter ablation (STW).

Electromechanical cardioplasty using a wrapped elasto-conductive epicardial mesh.

Heart failure remains a major public health concern with a 5-year mortality rate higher than that of most cancers. Myocardial disease in heart failure is frequently accompanied by impairment of the specialized electrical conduction system and myocardium. We introduce an epicardial mesh made of electrically conductive and mechanically elastic material, to resemble the innate cardiac tissue and confer cardiac conduction system function, to enable electromechanical cardioplasty.

Prolonged atrial refractoriness predicts the onset of atrial fibrillation: A 12-year follow-up study.

Background: Tissue refractoriness to conduction is a crucial electrophysiological factor in determining susceptibility to fibrillation. The relationship between atrial refractoriness and future onset of atrial fibrillation (AF) has not been well studied.

Objectives: We investigated whether atrial effective refractory period (AERP) was associated with AF occurrence in a relatively healthy population.

Rotors in patients with persistent atrial fibrillation: case report of a left atrial appendage rotor identified by a novel computational mapping algorithm integrated into 3-dimensional mapping and termination of atrial fibrillation with ablation.

Recent clinical trials using panoramic mapping techniques have shown success in targeting rotors and focal impulses in atrial fibrillation (AF). Ablations directed toward these organized sources improve outcomes in AF. The left atrial appendage (LAA) has been suspected as a possible extrapulmonary source of AF, and ablation within the LAA or electrical isolation of the LAA improves outcomes in certain cases.

Fragmented QRS as a candidate marker for high-risk assessment in hypertrophic cardiomyopathy.

Background: The relationship between a fragmented QRS complex (fQRS) on 12-lead ECG and fatal arrhythmic events in hypertrophic cardiomyopathy (HCM) remains unclear.

Objective: The purpose of this study was to investigate whether fQRS is associated with ventricular arrhythmic events (VAEs) in HCM patients.

Methods: Of an initial cohort of 273 patients (57% male, mean age 55 years) diagnosed with HCM, 167 patients were included and divided into 2 groups: those with fQRS (n = 67) and those without fQRS (n = 100).

Paced QT interval is a better predictor of mortality than the intrinsic QT interval: long-term follow-up study.

Background: Prolongation of the corrected QT (QTc) interval on 12-lead electrocardiogram is related to total mortality and sudden cardiac death. The value of the paced QTc interval in predicting mortality has not been investigated.

Objective: To evaluate the relationship between the paced QTc interval and mortality.

Multistage electrotherapy delivered through chronically-implanted leads terminates atrial fibrillation with lower energy than a single biphasic shock.

Objectives: The goal of this study was to develop a low-energy, implantable device-based multistage electrotherapy (MSE) to terminate atrial fibrillation (AF).

Background: Previous attempts to perform cardioversion of AF by using an implantable device were limited by the pain caused by use of a high-energy single biphasic shock (BPS).

Methods: Transvenous leads were implanted into the right atrium (RA), coronary sinus, and left pulmonary artery of 14 dogs.

A novel low-energy electrotherapy that terminates ventricular tachycardia with lower energy than a biphasic shock when antitachycardia pacing fails.

Objectives: The authors sought to develop a low-energy electrotherapy that terminates ventricular tachycardia (VT) when antitachycardia pacing (ATP) fails.

Background: High-energy implantable cardioverter-defibrillator (ICD) shocks are associated with device failure, significant morbidity, and increased mortality. A low-energy alternative to ICD shocks is desirable.

Remodeling of calcium handling in human heart failure.

Heart failure (HF) is an increasing public health problem accelerated by a rapidly aging global population. Despite considerable progress in managing the disease, the development of new therapies for effective treatment of HF remains a challenge. To identify targets for early diagnosis and therapeutic intervention, it is essential to understand the molecular and cellular basis of calcium handling and the signaling pathways governing the functional remodeling associated with HF in humans.

Altered systemic ketone body metabolism in advanced heart failure.

Heart failure is a systemic disease in which both myocardium and skeletal muscle exhibit alterations of energy metabolism. Failing myocardium exhibits impaired utilization of free fatty acids and glucose, which are major substrates for myocardial energy production. Ketone bodies normally provide a modest contribution to energy balance, but serum concentrations of ketone bodies are elevated in heart failure.

Low-energy multistage atrial defibrillation therapy terminates atrial fibrillation with less energy than a single shock.

Background: Implantable device therapy of atrial fibrillation (AF) is limited by pain from high-energy shocks. We developed a low-energy multistage defibrillation therapy and tested it in a canine model of AF.

Methods And Results: AF was induced by burst pacing during vagus nerve stimulation.

HIV-1 Nef binds the DOCK2-ELMO1 complex to activate rac and inhibit lymphocyte chemotaxis.

The infectious cycle of primate lentiviruses is intimately linked to interactions between cells of the immune system. Nef, a potent virulence factor, alters cellular environments to increase lentiviral replication in the host, yet the mechanisms underlying these effects have remained elusive. Since Nef likely functions as an adaptor protein, we exploited a proteomic approach to directly identify molecules that Nef targets to subvert the signaling machinery in T cells.

T-cell receptor:CD3 down-regulation is a selected in vivo function of simian immunodeficiency virus Nef but is not sufficient for effective viral replication in rhesus macaques.

We investigated the function of severely truncated simian immunodeficiency virus (SIV) Nef proteins (tNef) in vitro and in vivo. These variants emerged in rhesus monkeys infected with SIVmac239 containing a 152-bp deletion in the nef-unique region and have been suggested to enhance SIV virulence (E. T.