111,799 results match your criteria Electrophysiology

Deformation of stylet-driven leads & helix unraveling during acute explant after conduction system pacing.

Indian Pacing Electrophysiol J 2021 Jun 9. Epub 2021 Jun 9.

Stanford Health Care, Palo Alto, CA, USA; Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA.

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Utstein-style and the importance of the system, is it time for a new Utstein revision?

Resuscitation 2021 Jun 9. Epub 2021 Jun 9.

Division of Cardiology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.

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Magnetic resonance imaging in all patients with implanted cardiac devices - Yes, We Can!

Int J Cardiol 2021 Jun 9. Epub 2021 Jun 9.

Clinic for Electrophysiology, Herz- und Diabeteszentrum NRW, Ruhr-Universität Bochum, Bad Oeynhausen, Germany. Electronic address:

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Extracellular loops of the serotonin transporter act as a selectivity filter for drug binding.

J Biol Chem 2021 Jun 9:100863. Epub 2021 Jun 9.

The Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Austria.

The serotonin transporter (SERT) shapes serotonergic neurotransmission by retrieving its eponymous substrate from the synaptic cleft. Ligands which discriminate between SERT and its close relative, the dopamine transporter DAT, differ in their association rate constant rather than their dissociation rate. The structural basis for this phenomenon is not known. Read More

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Peripherally active dextromethorphan derivatives lower blood glucose levels by targeting pancreatic islets.

Cell Chem Biol 2021 Jun 2. Epub 2021 Jun 2.

Institute for Vascular and Islet Cell Biology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, 40225 Düsseldorf, Germany; Institute of Metabolic Physiology, Heinrich Heine University, 40225 Düsseldorf, Germany; Center of Competence for Innovative Diabetes Therapy (KomIT), German Diabetes Center (DDZ), 40225 Düsseldorf, Germany; German Center for Diabetes Research (DZD e.V.), Helmholtz Zentrum München, 85764 Neuherberg, Germany. Electronic address:

Dextromethorphan (DXM) acts as cough suppressant via its central action. Cell-protective effects of this drug have been reported in peripheral tissues, making DXM potentially useful for treatment of several common human diseases, such as type 2 diabetes mellitus (T2DM). Pancreatic islets are among the peripheral tissues that positively respond to DXM, and anti-diabetic effects of DXM were observed in two placebo-controlled, randomized clinical trials in humans with T2DM. Read More

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Cortical Responses to Vowel Sequences in Awake and Anesthetized States: A Human Intracranial Electrophysiology Study.

Cereb Cortex 2021 Jun 12. Epub 2021 Jun 12.

Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA.

Elucidating neural signatures of sensory processing across consciousness states is a major focus in neuroscience. Noninvasive human studies using the general anesthetic propofol reveal differential effects on auditory cortical activity, with a greater impact on nonprimary and auditory-related areas than primary auditory cortex. This study used intracranial electroencephalography to examine cortical responses to vowel sequences during induction of general anesthesia with propofol. Read More

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Clinical electrophysiology of the optic nerve and retinal ganglion cells.

Eye (Lond) 2021 Jun 11. Epub 2021 Jun 11.

College of Optometry, State University of New York, New York, NY, USA.

Clinical electrophysiological assessment of optic nerve and retinal ganglion cell function can be performed using the Pattern Electroretinogram (PERG), Visual Evoked Potential (VEP) and the Photopic Negative Response (PhNR) amongst other more specialised techniques. In this review, we describe these electrophysiological techniques and their application in diseases affecting the optic nerve and retinal ganglion cells with the exception of glaucoma. The disease groups discussed include hereditary, compressive, toxic/nutritional, traumatic, vascular, inflammatory and intracranial causes for optic nerve or retinal ganglion cell dysfunction. Read More

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Non-invasive electrophysiology in glaucoma, structure and function-a review.

Eye (Lond) 2021 Jun 11. Epub 2021 Jun 11.

Faculty of Medicine, Eye Center, Medical Center-University of Freiburg, Freiburg im Breisgau, Germany.

Glaucoma, its early diagnosis, and monitoring of interventions remain an ongoing challenge. We here review developments in functional assessment and its relation to morphology, evaluating recent insights in electrophysiology in glaucoma and highlighting how glaucoma research and diagnostics benefit from combined approaches of OCT and electrophysiological investigations. After concise overviews of OCT and non-invasive electrophysiology in glaucoma, we evaluate commonalities and complementarities of OCT and electrophysiology for our understanding of glaucoma. Read More

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Atrioventricular synchronous pacing using leadless pacemaker in a heart transplant patient.

BMJ Case Rep 2021 Jun 11;14(6). Epub 2021 Jun 11.

Department of Cardiology, Glenfield Hospital, Leicester, UK.

We report the first leadless pacemaker (L-PM) providing atrioventricular synchronous pacing implanted into a heart transplant patient receiving chronic immunosuppressive therapy. The patient presented with syncope corresponding to sinus rhythm with high-grade atrioventricular block. Previously, L-PMs provided only single-chamber ventricular sensing and pacing. Read More

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Subregion-specific effects on striatal neurotransmission and dopamine-signaling by acute and repeated amphetamine exposure.

Neuropharmacology 2021 Jun 8:108638. Epub 2021 Jun 8.

Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Sweden; Department of Pharmacology, Institute of Neuroscience and Physiology, Sahlgrenska Academy University of Gothenburg, Sweden. Electronic address:

Repeated administration of psychostimulants, such as amphetamine, is associated with a progressive increased sensitivity to some of the drug's effects, but tolerance towards others. We hypothesized that these adaptations in part could be linked to differential effects by amphetamine on dopaminergic signaling in striatal subregions. To test this theory, acute and long-lasting changes in dopaminergic neurotransmission were assessed in the nucleus accumbens (nAc) and the dorsomedial striatum (DMS) following amphetamine exposure in Wistar rats. Read More

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Performance and outcomes of transvenous rotational lead extraction: Results from a prospective, monitored, global clinical study-"An evolution in extraction".

Heart Rhythm O2 2021 Apr 19;2(2):122-123. Epub 2021 Mar 19.

Division of Cardiology, Cardiac Electrophysiology Program, Sulpizio Family Cardiovascular Center, La Jolla, California, and the University of California Medical Center, San Diego, California.

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Empiric catheter ablation of premature ventricular contractions when there is a >20% burden in an asymptomatic patient with normal left ventricular size and function-An argument for a conservative, do-less approach.

Kurt S Hoffmayer

Heart Rhythm O2 2021 Apr 26;2(2):210-214. Epub 2021 Feb 26.

Division of Cardiology, Section of Electrophysiology, University of California, San Diego, La Jolla, California.

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Empiric ablation of asymptomatic PVCs when there is greater than 20% burden but normal left ventricular function-An argument in support of catheter ablation.

Frederick T Han

Heart Rhythm O2 2021 Apr 26;2(2):205-209. Epub 2021 Feb 26.

Section of Cardiac Electrophysiology University of California, San Diego Cardiovascular Institute, La Jolla, California.

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Comparing patient and family usability of insertable cardiac monitors in a pediatric cohort: Patient external activator versus smartphone transmission.

Heart Rhythm O2 2021 Apr 13;2(2):201-204. Epub 2021 Mar 13.

Division of Pediatric Cardiology, Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri.

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Pregnancy-induced increased heart rate is independent of thyroid hormones.

Heart Rhythm O2 2021 Apr 4;2(2):168-173. Epub 2021 Mar 4.

Research Center, Montreal Heart Institute, Montreal, Canada.

Background: The heart rate increases by 10-20 beats per minute (bpm) throughout pregnancy in women, reaching maximum heart rate in the third trimester. During pregnancy, important changes in thyroid hormones also occur, with increases of up to 50% in the levels of triiodothyronine (T), the biological active thyroid hormone. In addition, T has been shown to regulate cardiac electrophysiology. Read More

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Performance and outcomes of transvenous rotational lead extraction: Results from a prospective, monitored, international clinical study.

Heart Rhythm O2 2021 Apr 2;2(2):113-121. Epub 2021 Mar 2.

Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany.

Background: Transvenous lead extraction (TLE) plays a critical role in managing patients with cardiovascular implantable electronic devices. Mechanical TLE tools, including rotational sheaths, are used to overcome fibrosis and calcification surrounding leads. Prospective clinical data are limited regarding the safety and effectiveness of use of mechanical TLE devices, especially rotational tools. Read More

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A novel approach to electrocardiography in the prone patient.

Heart Rhythm O2 2021 Feb 2;2(1):107-109. Epub 2020 Nov 2.

Section of Cardiac Electrophysiology, Denver Health and Hospital Authority, University of Colorado School of Medicine, Denver, Colorado.

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February 2021

Catheter ablation and healthcare utilization and cost among patients with paroxysmal versus persistent atrial fibrillation.

Heart Rhythm O2 2021 Feb 15;2(1):28-36. Epub 2020 Dec 15.

Electrophysiology Section, Duke University Hospital & Duke Clinical Research Institute, Durham, North Carolina.

Background: Ablation reduces atrial fibrillation (AF) burden and improves health-related quality of life. The relationship between ablation, healthcare utilization, and AF type (paroxysmal AF [PAF] vs persistent AF [PsAF]) remains unclear.

Objective: To compare changes in AF-related healthcare utilization and costs from preablation to postablation among patients with PAF and PsAF. Read More

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February 2021

Noninvasive electrocardiographic assessment of ventricular activation and remodeling response to cardiac resynchronization therapy.

Heart Rhythm O2 2021 Feb 12;2(1):12-18. Epub 2021 Jan 12.

School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.

Background: Cardiac resynchronization therapy (CRT) produces acute changes in electric resynchronization that can be measured noninvasively with electrocardiographic body surface mapping (ECGi). The relation between baseline acute electrophysiology metrics and their manipulation with CRT and reverse remodeling is unclear.

Objective: To test (ECGi) derived parameters of electrical activation as predictors of volumetric response to CRT. Read More

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February 2021

Secondary prevention of sudden cardiac death.

Heart Rhythm O2 2020 Oct 27;1(4):297-310. Epub 2020 Aug 27.

Division of General Internal Medicine, University of Washington, Seattle, Washington.

The prevention and treatment of sudden cardiac death (SCD) remains a significant public health challenge. For patients with a history of sudden death attributable to ventricular arrhythmia, implantable cardioverter-defibrillator (ICD) therapy is a mainstay of treatment, although these patients remain at high risk for recurrent ventricular arrhythmia and defibrillator therapies. In this review, we summarize landmark clinical trials evaluating the efficacy of ICD therapy in secondary prevention patients, review clinical outcomes including mode of death in survivors of SCD, and highlight the role for systematic diagnostic evaluation. Read More

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October 2020

Bipolar ablation's unique paradigm: Duration and power as respectively distinct primary determinants of transmurality and steam pop formation.

Heart Rhythm O2 2020 Oct 24;1(4):290-296. Epub 2020 Jun 24.

Department of Electrophysiology Clinical Research and Innovations, Texas Heart Institute, Houston, Texas.

Background: Bipolar radiofrequency (RF) ablation strategies are increasingly used, mainly to target deep myocardial reentrant circuits responsible for ventricular tachycardia that cannot be extinguished with traditional unipolar RF ablation. Because this strategy is novel, factors that affect lesion geometry and steam pop formation require further investigation.

Objective: To assess the effect of contact force, power, and time on the resulting lesion geometry and the risk of steam pop formation during bipolar RF ablation of thick myocardial tissue. Read More

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October 2020

Sex differences in left ventricular electrical dyssynchrony and outcomes with cardiac resynchronization therapy.

Heart Rhythm O2 2020 Oct 4;1(4):243-249. Epub 2020 Aug 4.

Section of Cardiac Electrophysiology, Duke University School of Medicine, Durham, North Carolina.

Background: Women seem to derive more benefit from cardiac resynchronization therapy (CRT) than men, even after accounting for the higher burden of risk factors for nonresponse often observed in men.

Objective: To assess for sex-specific differences in left ventricular (LV) electrical dyssynchrony as a contributing electrophysiological explanation for the greater degree of CRT benefit among women.

Methods: We compared the extent of baseline LV electrical dyssynchrony, as measured by the QRS area (QRSA), among men and women with left bundle branch block (LBBB) undergoing CRT at Duke University (n = 492, 35% women) overall and in relation to baseline QRS characteristics using independent sample tests and Pearson correlation coefficients. Read More

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October 2020

The wearable cardioverter-defibrillator is needed for most high-risk patients.

Byron K Lee

Heart Rhythm O2 2020 Aug 14;1(3):227-229. Epub 2020 Jul 14.

Electrophysiology and Arrhythmia Service, Division of Cardiology, University of California, San Francisco, San Francisco, California.

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Risk of atrioesophageal fistula with cryoballoon ablation of atrial fibrillation.

Heart Rhythm O2 2020 Aug 28;1(3):173-179. Epub 2020 May 28.

Virginia Commonwealth University Medical Center, Richmond, Virginia.

Background: Although there are considerable data on the safety of cryoablation, data on the rare but severe complication of atrioesophageal fistula (AEF) following cryoballoon ablation are limited.

Objective: To report the global, user-reported incidence of AEF associated with cryoballoon ablation for the treatment of atrial fibrillation using Medtronic's complaint database.

Methods: User-reported cryoballoon ablation complications occurring between July 1, 2009, and March 31, 2019, were reviewed to identify cases of AEF. Read More

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What goes in may need to come out: Considerations in the extraction of a lumenless, fixed-screw permanent pacemaker lead.

Heart Rhythm O2 2020 Jun 11;1(2):160-163. Epub 2020 May 11.

Department of Cardiac Electrophysiology, University of California San Diego Medical Center, La Jolla, California.

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Novel beta-blocker pretreatment prevents alcohol-induced atrial fibrillation in a rat model.

Heart Rhythm O2 2020 Jun 15;1(2):120-125. Epub 2020 Jun 15.

Department of Clinical Specialties, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York.

Background: A case report published in 2019 described a patient who presented with difficult-to-manage atrial fibrillation (AF) that consistently was associated with alcohol consumption. After the patient did not respond to drug therapy, a novel beta-blocker (BB) pretreatment regimen initiated immediately before alcohol consumption successfully prevented AF occurrence.

Objective: The purpose of this study was to test the hypothesis that a novel prophylactic BB therapy given before alcohol consumption could prevent AF in a rat model. Read More

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Introducing a novel catheter-tissue contact feedback feature in robotic navigated catheter ablation: Utility, feasibility, and safety.

Heart Rhythm O2 2020 Jun 11;1(2):103-110. Epub 2020 May 11.

Department of Cardiology, Thoraxcenter, Erasmus MC, Rotterdam, The Netherlands.

Background: The quality of catheter-tissue contact is one of the most important determinants of catheter ablation (CA) success. The absence of catheter-tissue contact feedback has been regarded a major limitation of remote magnetic navigation (RMN)-guided CA. The e-Contact module (ECM) is a novel feature designed for RMN that measures the quality of catheter-tissue contact. Read More

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Left bundle branch pacing is the best approach to physiological pacing.

Heart Rhythm O2 2020 Apr 27;1(1):59-67. Epub 2020 Apr 27.

Department of Cardiac Electrophysiology, Virginia Commonwealth University, Richmond, Virginia.

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Wire countertraction for sheath placement through stenotic and tortuous veins: The "body flossing" technique.

Heart Rhythm O2 2020 Apr 27;1(1):21-26. Epub 2020 Apr 27.

Section of Cardiac Electrophysiology, Cardiovascular Division, Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.

Background: Innominate vein stenosis and venous tortuosity are common findings during cardiac implantable electronic device upgrades or replacements and present a challenge to the implanting physician. Various techniques have been described to facilitate lead placement, including serial dilation, balloon venoplasty, and percutaneous access medial to the stenosis, each with its own benefits and risks.

Objective: The purpose of this study was to assess the feasibility, safety, and efficacy of the wire countertraction ("body flossing") technique to facilitate sheath placement through tortuous and stenotic vessels. Read More

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Screening for atrial fibrillation in high-risk nursing home residents.

Heart Rhythm O2 2020 Apr 27;1(1):10-13. Epub 2020 Apr 27.

Department of Medicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York.

Background: Various methods have been implemented for screening of patients for atrial fibrillation (AF), but the yield has generally been low. Targeting high-risk patients may improve detection of asymptomatic AF, which could be of value if appropriate treatment could be initiated before a potential thromboembolic event.

Objective: The purpose of this study was to test screening of high-risk nursing home residents having ≥2 risk factors for AF and no previous history of AF using a smartphone-based electrocardiographic (ECG) monitoring device to determine whether it is an accurate, easy-to-use method of screening for asymptomatic AF. Read More

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