Effects of anesthetic and sedative agents on sympathetic nerve activity.

Background: The effects of sedative and anesthetic agents on sympathetic nerve activity (SNA) are poorly understood.

Objective: The purpose of this study was to determine the effects of commonly used sedative and anesthetic agents on SNA in ambulatory dogs and humans.

Methods: We implanted radiotransmitters in 6 dogs to record stellate ganglion nerve activity (SGNA), subcutaneous nerve activity (ScNA), and blood pressure (BP).

Characterization of skin sympathetic nerve activity in patients with cardiomyopathy and ventricular arrhythmia.

Background: Heightened sympathetic nerve activity is associated with occurrence of ventricular arrhythmia (VA).

Objective: To investigate the association of skin sympathetic nerve activity (SKNA) and VA occurrence.

Methods: We prospectively enrolled 65 patients with severe cardiomyopathy.

Renal Denervation Update From the International Sympathetic Nervous System Summit: JACC State-of-the-Art Review.

Three recent renal denervation studies in both drug-naïve and drug-treated hypertensive patients demonstrated a significant reduction of ambulatory blood pressure compared with respective sham control groups. Improved trial design, selection of relevant patient cohorts, and optimized interventional procedures have likely contributed to these positive findings. However, substantial variability in the blood pressure response to renal denervation can still be observed and remains a challenging and important problem.

Subcutaneous nerve stimulation for rate control in ambulatory dogs with persistent atrial fibrillation.

Background: Subcutaneous nerve stimulation (ScNS) damages the stellate ganglion and improves rhythm control of atrial fibrillation (AF) in ambulatory dogs.

Objective: The purpose of this study was to test the hypothesis that thoracic ScNS can improve rate control in persistent AF.

Methods: We created persistent AF in 13 dogs and randomly assigned them to ScNS (n = 6) and sham control (n = 7) groups.

Weighted Gene Co-expression Network Analysis for RNA-Sequencing Data of the Varicose Veins Transcriptome.

Objective: Varicose veins are a common problem worldwide and can cause significant impairments in health-related quality of life, but the etiology and pathogenesis remain not well defined. This study aims to elucidate transcriptomic regulations of varicose veins by detecting differentially expressed genes, pathways and regulator genes.

Methods: We harvested great saphenous veins (GSV) from patients who underwent coronary artery bypass grafting (CABG) and varicose veins from conventional stripping surgery.

Doxorubicin Exposure Causes Subacute Cardiac Atrophy Dependent on the Striated Muscle-Specific Ubiquitin Ligase MuRF1.

Background Anthracycline chemotherapeutics, such as doxorubicin, are used widely in the treatment of numerous malignancies. The primary dose-limiting adverse effect of anthracyclines is cardiotoxicity that often presents as heart failure due to dilated cardiomyopathy years after anthracycline exposure. Recent data from animal studies indicate that anthracyclines cause cardiac atrophy.

Antiarrhythmic and proarrhythmic effects of subcutaneous nerve stimulation in ambulatory dogs.

Background: High output subcutaneous nerve stimulation (ScNS) remodels the stellate ganglia and suppresses cardiac arrhythmia.

Objective: The purpose of this study was to test the hypothesis that long duration low output ScNS causes cardiac nerve sprouting and increases plasma norepinephrine concentration and the duration of paroxysmal atrial tachycardia (PAT) in ambulatory dogs.

Methods: We prospectively randomized 22 dogs (11 males and 11 females) into 5 different output groups for 2 months of ScNS: 0 mA (sham) (n = 6), 0.

Skin sympathetic nerve activity and the temporal clustering of cardiac arrhythmias.

Background: Simultaneous noninvasively recorded skin sympathetic nerve activity (SKNA) and electrocardiogram (neuECG) can be used to estimate cardiac sympathetic tone. We tested the hypothesis that large and prolonged SKNA bursts are associated with temporal clustering arrhythmias.

Methods: We recorded neuECG in 10 patients (69 ± 10 years old) with atrial fibrillation (AF) episodes and in 6 patients (50 ± 13 years old) with ventricular tachycardia (VT) or fibrillation (VF) episodes.

Atrial fibrillation and electrophysiology in transgenic mice with cardiac-restricted overexpression of FKBP12.

Cardiomyocyte-restricted overexpression of FK506-binding protein 12 transgenic (αMyHC-FKBP12) mice develop spontaneous atrial fibrillation (AF). The aim of the present study is to explore the mechanisms underlying the occurrence of AF in αMyHC-FKBP12 mice. Spontaneous AF was documented by telemetry in vivo and Langendorff-perfused hearts of αMyHC-FKBP12 and littermate control mice in vitro.

Small-conductance calcium-activated potassium current modulates the ventricular escape rhythm in normal rabbit hearts.

Background: The apamin-sensitive small-conductance calcium-activated K (SK) current I modulates automaticity of the sinus node. I blockade by apamin causes sinus bradycardia.

Objective: The purpose of this study was to test the hypothesis that I modulates ventricular automaticity.

Phospholamban regulates nuclear Ca stores and inositol 1,4,5-trisphosphate mediated nuclear Ca cycling in cardiomyocytes.

Aims: Phospholamban (PLB) is the key regulator of the cardiac Ca pump (SERCA2a)-mediated sarcoplasmic reticulum Ca stores. We recently reported that PLB is highly concentrated in the nuclear envelope (NE) from where it can modulate perinuclear Ca handling of the cardiomyocytes (CMs). Since inositol 1,4,5-trisphosphate (IP) receptor (IPR) mediates nuclear Ca release, we examined whether the nuclear pool of PLB regulates IP-induced nuclear Ca handling.

Muscle-specific regulation of right ventricular transcriptional responses to chronic hypoxia-induced hypertrophy by the muscle ring finger-1 (MuRF1) ubiquitin ligase in mice.

Background: We recently identified a role for the muscle-specific ubiquitin ligase MuRF1 in right-sided heart failure secondary to pulmonary hypertension induced by chronic hypoxia (CH). MuRF1-/- mice exposed to CH are resistant to right ventricular (RV) dysfunction whereas MuRF1 Tg + mice exhibit impaired function indicative of heart failure. The present study was undertaken to understand the underlying transcriptional alterations in the RV of MuRF1-/- and MuRF1 Tg + mice.

Prospective Multicenter Experience With Cooled Radiofrequency Ablation Using High Impedance Irrigant to Target Deep Myocardial Substrate Refractory to Standard Ablation.

Objectives: This study sought to evaluate the efficacy and safety of using half-normal saline (HNS) as the cooling radiofrequency ablation (RFA) irrigant among patients who had failed prior, standard RFA.

Background: Effective control of ventricular arrhythmias that arise from mid-myocardium may be refractory to standard RFA. Recent data suggest that delivering fluid with decreased ionic concentration during open-irrigated RFA can produce deeper RFA lesions.

Effects of Vagal Nerve Stimulation on Ganglionated Plexi Nerve Activity and Ventricular Rate in Ambulatory Dogs With Persistent Atrial Fibrillation.

Objectives: This study was designed to test the hypothesis that low-level vagal nerve stimulation (VNS) reduces the ventricular rate (VR) during atrial fibrillation (AF) through the activation of the inferior vena cava (IVC)-inferior atrial ganglionated plexus nerve activity (IAGPNA).

Background: Increased IVC-IAGPNA can suppress atrioventricular node conduction and slow VR in canine models of AF.

Methods: Persistent AF was induced in 6 dogs and the IVC-IAGPNA, right vagal nerve activity, left vagal nerve activity, and an electrocardiogram were recorded.

Epicardial Fat Distribution Assessed with Cardiac CT in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy.

Purpose To compare epicardial fat in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) with that in healthy subjects. Materials and Methods In this retrospective study, cardiac CT scans in 44 patients with ARVD/C (mean age, 39 years ± 12; 23 men) were compared with those in 45 control group participants between January 2008 and July 2015. Volumes of intrathoracic adipose tissue, mediastinal adipose tissue (MAT), and total epicardial adipose tissue (EAT) were quantified.

His Bundle Pacing.

Traditional right ventricular (RV) pacing for the management of bradyarrhythmias has been pursued successfully for decades, although there remains debate regarding optimal pacing site with respect to both hemodynamic and clinical outcomes. The deleterious effects of long-term RV apical pacing have been well recognized. This has generated interest in approaches providing more physiological stimulation, namely, His bundle pacing (HBP).

Sex-specific activation of SK current by isoproterenol facilitates action potential triangulation and arrhythmogenesis in rabbit ventricles.

Key Points: It is unknown if a sex difference exists in cardiac apamin-sensitive small conductance Ca -activated K (SK) current (I ). There is no sex difference in I in the basal condition. However, there is larger I in female rabbit ventricles than in male during isoproterenol infusion.

Phosphorylation of the RSRSP stretch is critical for splicing regulation by RNA-Binding Motif Protein 20 (RBM20) through nuclear localization.

RBM20 is a major regulator of heart-specific alternative pre-mRNA splicing of TTN encoding a giant sarcomeric protein titin. Mutation in RBM20 is linked to autosomal-dominant familial dilated cardiomyopathy (DCM), yet most of the RBM20 missense mutations in familial and sporadic cases were mapped to an RSRSP stretch in an arginine/serine-rich region of which function remains unknown. In the present study, we identified an R634W missense mutation within the stretch and a G1031X nonsense mutation in cohorts of DCM patients.

Cost-effectiveness analysis of magnetic resonance imaging-conditional pacemaker implantation: Insights from a multicenter study and implications in the current era.

Background: Magnetic resonance imaging (MRI)-conditional pacemakers (M-PPMs) grant patients greater accessibility to MRI scans. The cost-effectiveness of implanting M-PPM is unknown.

Objective: The purpose of this study was to determine the cost-effectiveness of M-PPM implantation.

Effects of Stellate Ganglion Cryoablation on Subcutaneous Nerve Activity and Atrial Tachyarrhythmias in a Canine Model of Pacing-Induced Heart Failure.

Objectives: This study aimed to test the hypothesis that subcutaneous nerve activity (SCNA) can adequately estimate the cardiac sympathetic tone and the effects of cryoablation of the stellate ganglion in dogs with pacing-induced heart failure (HF).

Background: Recording of SCNA is a new method to estimate sympathetic tone in dogs. HF is known to increase sympathetic tone and atrial arrhythmias.

A comprehensive review and meta-analysis of risk factors for statin-induced myopathy.

Purpose: To aid prescribers in assessing a patient's risk for statin-induced myopathy (SIM), we performed a comprehensive review of currently known risk factors and calculated aggregated odds ratios for each risk factor through a meta-analysis.

Methods: This meta-analysis was done through four phases: (1) Identification of the relevant primary literature; (2) abstract screening using inclusion and exclusion criteria; (3) detailed review and data extraction; and (4) synthesis and statistical analysis.

Results: Out of 44 papers analyzed from 836 papers searched from MEDLINE, 18 different potential risk factors were collected, divided into three categories: three demographics (11 papers), ten clinical factors (31 papers), and five pharmacogenetics/biomarkers (12 papers).