528 results match your criteria Electrical Alternans


Diagnostic value of electrocardiogram in cardiac tamponade.

Med J Malaysia 2019 Feb;74(1):51-56

Sultanah Aminah Hospital, Department of Cardiology, Johor Bahru, Johor, Malaysia.

Introduction: We aim to study the diagnostic value of electrocardiogram (ECG) in cardiac tamponade.

Methods: This study was a single centre, retrospective casecontrol study. We recruited 42 patients diagnosed with cardiac tamponade of various aetiologies confirmed by transthoracic echocardiography and 100 controls between January 2011 and December 2015. Read More

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February 2019
1 Read

Neutrophil-lymphocyte ratio: A prognostic tool in patients with in-hospital cardiac arrest.

World J Crit Care Med 2019 Feb 21;8(2):9-17. Epub 2019 Feb 21.

Department of Cardiovascular Medicine, Ascension-St John Hospital and Medical Center, Detroit, MI 48236, United States.

Background: In-hospital cardiac arrest (IHCA) portends a poor prognosis and survival to discharge rate. Prognostic markers such as interleukin-6, S-100 protein and high sensitivity C reactive protein have been studied as predictors of adverse outcomes after return of spontaneous circulation (ROSC); however; these variables are not routine laboratory tests and incur additional cost making them difficult to incorporate and less attractive in assessing patient's prognosis. The neutrophil-lymphocyte ratio (NLR) is a marker of adverse prognosis for many cardiovascular conditions and certain types of cancers and sepsis. Read More

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https://www.wjgnet.com/2220-3141/full/v8/i2/9.htm
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http://dx.doi.org/10.5492/wjccm.v8.i2.9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6388309PMC
February 2019
1 Read

Pulse Arrival Time and Pulse Interval as Accurate Markers to Detect Mechanical Alternans.

Ann Biomed Eng 2019 Feb 12. Epub 2019 Feb 12.

Department of Mechanical Engineering, University College London, London, UK.

Mechanical alternans (MA) is a powerful predictor of adverse prognosis in patients with heart failure and cardiomyopathy, but its use remains limited due to the need of invasive continuous arterial pressure recordings. This study aims to assess novel cardiovascular correlates of MA in the intact human heart to facilitate affordable and non-invasive detection of MA and advance our understanding of the underlying pathophysiology. Arterial pressure, respiration, and ECG were recorded in 12 subjects with healthy ventricles during voluntarily controlled breathing at different respiratory rate, before and after administration of beta-blockers. Read More

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http://dx.doi.org/10.1007/s10439-019-02221-4DOI Listing
February 2019
1 Read

Mechanistic insights from targeted molecular profiling of repolarization alternans in the intact human heart.

Europace 2019 Feb 8. Epub 2019 Feb 8.

Institute of Cardiovascular Science, University College London, London, UK.

Aims: Action potential duration (APD) alternans is an established precursor or arrhythmia and sudden cardiac death. Important differences in fundamental electrophysiological properties relevant to arrhythmia exist between experimental models and the diseased in vivo human heart. To investigate mechanisms of APD alternans using a novel approach combining intact heart and cellular cardiac electrophysiology in human in vivo. Read More

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http://dx.doi.org/10.1093/europace/euz007DOI Listing
February 2019
3 Reads

Supraventricular tachycardia with QRS and cycle length alternans. What is the diagnosis?

Hellenic J Cardiol 2019 Jan 23. Epub 2019 Jan 23.

2(nd) Department of Cardiology, General Hospital of Nikea-Piraeus "Agios Panteleimon", D. Mantouvalou 3, 18454, Piraeus, Greece.

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http://dx.doi.org/10.1016/j.hjc.2019.01.006DOI Listing
January 2019
1 Read

Acute Influenza Infection Presenting with Cardiac Tamponade: A Case Report and Review of Literature.

Perm J 2019 ;23:18-104

Department of Pulmonary and Critical Care, University of Arkansas for Medical Sciences Medical Center, Little Rock.

Introduction: Cardiac complications associated with influenza infection can occur either via a direct effect of the virus on the heart or through exacerbation of preexisting cardiovascular disease. We present a case of a 57-year-old man with acute influenza infection complicated by pericardial effusion and cardiac tamponade.

Case Presentation: A 57-year-old white man presented to the Emergency Department with sudden onset of severe, nonexertional, retrosternal, pressure-like chest pain for a few hours and with fever and muscle aches for 2 days. Read More

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http://dx.doi.org/10.7812/TPP/18-104DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6326557PMC
January 2019
1 Read

Mechanistic insight into spontaneous transition from cellular alternans to arrhythmia-A simulation study.

PLoS Comput Biol 2018 11 30;14(11):e1006594. Epub 2018 Nov 30.

Biological Physics Group, School of Physics & Astronomy, The University of Manchester, Manchester, United Kingdom.

Cardiac electrical alternans (CEA), manifested as T-wave alternans in ECG, is a clinical biomarker for predicting cardiac arrhythmias and sudden death. However, the mechanism underlying the spontaneous transition from CEA to arrhythmias remains incompletely elucidated. In this study, multiscale rabbit ventricular models were used to study the transition and a potential role of INa in perpetuating such a transition. Read More

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http://dx.doi.org/10.1371/journal.pcbi.1006594DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6291170PMC
November 2018
2 Reads

Concomitant SK current activation and sodium current inhibition cause J wave syndrome.

JCI Insight 2018 Nov 15;3(22). Epub 2018 Nov 15.

Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA.

The mechanisms of J wave syndrome (JWS) are incompletely understood. Here, we showed that the concomitant activation of small-conductance calcium-activated potassium (SK) current (IKAS) and inhibition of sodium current by cyclohexyl-[2-(3,5-dimethyl-pyrazol-1-yl)-6-methyl-pyrimidin-4-yl]-amine (CyPPA) recapitulate the phenotypes of JWS in Langendorff-perfused rabbit hearts. CyPPA induced significant J wave elevation and frequent spontaneous ventricular fibrillation (SVF), as well as sinus bradycardia, atrioventricular block, and intraventricular conduction delay. Read More

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https://insight.jci.org/articles/view/122329
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http://dx.doi.org/10.1172/jci.insight.122329DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6302939PMC
November 2018
15 Reads

Electrical Alternans in Disguise-A Curious Case of Atrial Flutter.

JAMA Intern Med 2018 Dec;178(12):1704-1705

Department of Medicine, University of California, San Francisco, San Francisco.

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http://dx.doi.org/10.1001/jamainternmed.2018.5291DOI Listing
December 2018
2 Reads

Calcium in the Pathophysiology of Atrial Fibrillation and Heart Failure.

Front Physiol 2018 4;9:1380. Epub 2018 Oct 4.

Unit of Cardiac Physiology, Division of Cardiovascular Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom.

Atrial fibrillation (AF) is commonly associated with heart failure. A bidirectional relationship exists between the two-AF exacerbates heart failure causing a significant increase in heart failure symptoms, admissions to hospital and cardiovascular death, while pathological remodeling of the atria as a result of heart failure increases the risk of AF. A comprehensive understanding of the pathophysiology of AF is essential if we are to break this vicious circle. Read More

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https://www.frontiersin.org/article/10.3389/fphys.2018.01380
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http://dx.doi.org/10.3389/fphys.2018.01380DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6180171PMC
October 2018
22 Reads

Geometry-Dependent Arrhythmias in Electrically Excitable Tissues.

Cell Syst 2018 Oct 3;7(4):359-370.e6. Epub 2018 Oct 3.

Department of Physics, Harvard University, Cambridge, MA 02138, USA; Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA; Howard Hughes Medical Institute, Cambridge, MA 02138, USA. Electronic address:

Little is known about how individual cells sense the macroscopic geometry of their tissue environment. Here, we explore whether long-range electrical signaling can convey information on tissue geometry to individual cells. First, we studied an engineered electrically excitable cell line. Read More

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http://dx.doi.org/10.1016/j.cels.2018.08.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6204347PMC
October 2018
4 Reads

Synchronization of Triggered Waves in Atrial Tissue.

Biophys J 2018 Sep 18;115(6):1130-1141. Epub 2018 Aug 18.

Department of Medicine (Cardiology) and The Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois.

When an atrial cell is paced rapidly, calcium (Ca) waves can form on the cell boundary and propagate to the cell interior. These waves are referred to as "triggered waves" because they are initiated by Ca influx from the L-type Ca channel and occur during the action potential. However, the consequences of triggered waves in atrial tissue are not known. Read More

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http://dx.doi.org/10.1016/j.bpj.2018.08.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6139957PMC
September 2018
21 Reads

Pericardial effusion and electrical alternans.

QJM 2019 Feb;112(2):135-136

Department of Internal Medicine, Post Graduate Institute of Medical Education and Research, 4th floor, F block, Chandigarh, India.

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http://dx.doi.org/10.1093/qjmed/hcy191DOI Listing
February 2019
4 Reads

Clinical Outcomes and Modes of Death in Timothy Syndrome: A Multicenter International Study of a Rare Disorder.

JACC Clin Electrophysiol 2018 Apr 6;4(4):459-466. Epub 2017 Nov 6.

Department of Pediatrics, Division of Pediatric Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania. Electronic address:

Objectives: The objective of this study was to evaluate contemporary clinical outcomes and identify triggers for arrhythmias or sudden death in an international cohort of Timothy Syndrome (TS) patients including those with novel TS-associated CACNA1C mutations.

Background: TS is an extremely rare genetic disorder of the L-type cardiac channel Ca1.2 encoded by CACNA1C. Read More

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http://dx.doi.org/10.1016/j.jacep.2017.08.007DOI Listing
April 2018
5 Reads

Rapid Fire: Pericardial Effusion and Tamponade.

Emerg Med Clin North Am 2018 Aug 11;36(3):557-565. Epub 2018 Jun 11.

Department of Emergency Medicine, University of Maryland Medical Center, 110 South Paca Street, 6th Floor, Suite 200, Baltimore, MD 21201, USA. Electronic address:

One of the most common causes of pericardial effusion in the Western world is malignancy. Emergency physicians must maintain vigilance in suspecting pericardial effusion and tamponade in patients with known or suspected malignancy who present with tachycardia, dyspnea, and hypotension. Diagnosis can be expedited by key physical examination, electrocardiogram, and sonographic findings. Read More

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http://dx.doi.org/10.1016/j.emc.2018.04.004DOI Listing
August 2018
6 Reads

Massive pericardial effusion: A rare and easily missed finding in myocardial perfusion scintigraphy.

World J Nucl Med 2018 Jul-Sep;17(3):198-200

Nuclear Medicine Unit, Queen Elizabeth Hospital, Kowloon, Hong Kong, China.

A 72-year-old gentleman underwent myocardial perfusion scintigraphy (MPS) for sinus tachycardia of unknown cause. Baseline electrocardiography (ECG) showed sinus tachycardia and electrical alternans. Thallium-201 stress-redistribution MPS was performed with dipyridamole stress. Read More

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http://dx.doi.org/10.4103/wjnm.WJNM_39_17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6034550PMC
July 2018
2 Reads

Total electrical alternans in a patient with malignant pericardial tamponade.

BMJ Case Rep 2018 Jul 19;2018. Epub 2018 Jul 19.

Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands.

We present a case of a 59-year-old man with acute abdominal pain and progressive shortness of breath. A focused assessment with sonography for trauma scan showed free fluid in the hepatorenal recess and in the recto-uterine recess. Later, due to clinical deterioration and the differential possibility of a pulmonary embolism or aortic dissection, a CT scan was performed which revealed large pericardial effusion. Read More

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http://casereports.bmj.com/lookup/doi/10.1136/bcr-2018-22477
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http://dx.doi.org/10.1136/bcr-2018-224771DOI Listing
July 2018
17 Reads

Reduced T wave alternans in heart failure responders to cardiac resynchronization therapy: Evidence of electrical remodeling.

PLoS One 2018 28;13(6):e0199637. Epub 2018 Jun 28.

Peter Munk Cardiac Center, Division of Cardiology, University Health Network, Toronto, ON, Canada.

Background: T-wave alternans (TWA), a marker of electrical instability, can be modulated by cardiac resynchronization therapy (CRT). The relationship between TWA and heart failure response to CRT has not been clearly defined.

Methods And Results: In 40-patients (age 65±11 years, left ventricular ejection-fraction [LVEF] 23±7%), TWA was evaluated prospectively at median of 2 months (baseline) and 8 months (follow-up) post-CRT implant. Read More

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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0199637PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6023131PMC
December 2018
3 Reads

Mechanical perturbation control of cardiac alternans.

Phys Rev E 2018 May;97(5-1):052407

Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2V4.

Cardiac alternans is a disturbance in heart rhythm that is linked to the onset of lethal cardiac arrhythmias. Mechanical perturbation control has been recently used to suppress alternans in cardiac tissue of relevant size. In this control strategy, cardiac tissue mechanics are perturbed via active tension generated by the heart's electrical activity, which alters the tissue's electric wave profile through mechanoelectric coupling. Read More

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http://dx.doi.org/10.1103/PhysRevE.97.052407DOI Listing
May 2018
2 Reads

Targeted ablation of cardiac sympathetic neurons improves ventricular electrical remodelling in a canine model of chronic myocardial infarction.

Europace 2018 Dec;20(12):2036-2044

Department of Cardiology, Renmin Hospital of Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.

Aims: The purpose of this study was to evaluate the cardiac electrophysiologic effects of targeted ablation of cardiac sympathetic neurons (TACSN) in a canine model of chronic myocardial infarction (MI).

Methods And Results: Thirty-eight anaesthetized dogs were randomly assigned into the sham-operated, MI, and MI-TACSN groups, respectively. Myocardial infarction-targeted ablation of cardiac sympathetic neuron was induced by injecting cholera toxin B subunit-saporin compound in the left stellate ganglion (LSG). Read More

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http://dx.doi.org/10.1093/europace/euy090DOI Listing
December 2018
7 Reads

True vs. pseudo-electrical ventricular alternans sustained by ventricular premature complexes.

Herzschrittmacherther Elektrophysiol 2018 Jun;29(2):233-235

Biotronik, Berlin, Germany.

This report describes a form of electrical ventricular alternans sustained by ventricular premature complexes (VPC). Alternans was associated with a constant heart rate (RR interval) and was therefore considered to be either a form of classic or true alternans or a mimic of the configuration seen in true alternans from other causes. In contrast, VPC-induced pseudo-alternans is characterized by an inconstant heart rate (RR interval). Read More

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http://dx.doi.org/10.1007/s00399-018-0572-0DOI Listing
June 2018
4 Reads

Utility of heart rate turbulence and T-wave alternans to assess risk for readmission and cardiac death in hospitalized heart failure patients.

J Cardiovasc Electrophysiol 2018 Sep 6;29(9):1257-1264. Epub 2018 Jun 6.

Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan.

Background: Heart failure (HF) patients have a higher risk of recurrent HF and cardiac death, and electrical remodeling is considered to be an important factor for HF progression. The present study aimed to validate the utility of electrocardiogram and Holter monitoring for the risk stratification of HF patients.

Methods: Our study comprised 215 patients (144 males, mean age 62 years) who had been hospitalized due to acute decompensated HF. Read More

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http://dx.doi.org/10.1111/jce.13639DOI Listing
September 2018
24 Reads

Disruption of neonatal cardiomyocyte physiology following exposure to bisphenol-a.

Sci Rep 2018 May 9;8(1):7356. Epub 2018 May 9.

Sheikh Zayed Institute for Pediatric and Surgical Innovation, Children's National Health System, Washington, USA.

Bisphenol chemicals are commonly used in the manufacturing of polycarbonate plastics, polyvinyl chloride plastics, resins, and thermal printing applications. Humans are inadvertently exposed to bisphenols through contact with consumer products and/or medical devices. Recent reports have shown a link between bisphenol-a (BPA) exposure and adverse cardiovascular outcomes; although these studies have been limited to adult subjects and models. Read More

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http://dx.doi.org/10.1038/s41598-018-25719-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5943481PMC
May 2018
3 Reads
5.080 Impact Factor

Electrical stimulation-based renal nerve mapping exacerbates ventricular arrhythmias during acute myocardial ischaemia.

J Hypertens 2018 Jun;36(6):1342-1350

Objective: Blood pressure elevation in response to transient renal nerve stimulation (RNS) has been used to determine the ablation target and endpoint of renal denervation. This study aimed to evaluate the safety of transient RNS in canines with normal or ischaemic hearts.

Methods: In ten normal (Group 1) and six healed myocardial infarction (HMI) (Group 2) canines, a large-tip catheter was inserted into the left or right renal artery to perform transient RNS. Read More

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http://dx.doi.org/10.1097/HJH.0000000000001712DOI Listing
June 2018
11 Reads
4.720 Impact Factor

Sympathetic Nervous Regulation of Calcium and Action Potential Alternans in the Intact Heart.

Front Physiol 2018 23;9:16. Epub 2018 Jan 23.

School of Cardiovascular Medicine and Sciences, King's College London, United Kingdom.

Arrhythmogenic cardiac alternans are thought to be an important determinant for the initiation of ventricular fibrillation. There is limited information on the effects of sympathetic nerve stimulation (SNS) on alternans in the intact heart and the conclusions of existing studies, focused on investigating electrical alternans, are conflicted. Meanwhile, several lines of evidence implicate instabilities in Ca handling, not electrical restitution, as the primary mechanism underpinning alternans. Read More

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http://dx.doi.org/10.3389/fphys.2018.00016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5787134PMC
January 2018
2 Reads

Electrical and mechanical alternans during ventricular tachycardia with moderate chronic heart failure.

J Electrocardiol 2018 Jan - Feb;51(1):33-37. Epub 2017 Sep 23.

Sarver Heart Center, University of Arizona, Tucson, AZ, United States. Electronic address:

A chronic heart failure (CHF) rat underwent epicardial programmed electrical stimulation (PES). Ventricular tachycardia (VT) developed during PES. Mechanical alternans was noted despite fixed tachycardia cycle length. Read More

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http://dx.doi.org/10.1016/j.jelectrocard.2017.09.002DOI Listing
February 2019
11 Reads
1.363 Impact Factor

Temperature, geometry, and bifurcations in the numerical modeling of the cardiac mechano-electric feedback.

Chaos 2017 Sep;27(9):093924

GIGA In silico medicine, Liège University, B-4000 Liège, Belgium.

This article characterizes the cardiac autonomous electrical activity induced by the mechanical deformations in the cardiac tissue through the mechano-electric feedback. A simplified and qualitative model is used to describe the system and we also account for temperature effects. The analysis emphasizes a very rich dynamics for the system, with periodic solutions, alternans, chaotic behaviors, etc. Read More

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http://dx.doi.org/10.1063/1.5000710DOI Listing
September 2017
2 Reads

Effects of model error on cardiac electrical wave state reconstruction using data assimilation.

Chaos 2017 Sep;27(9):093911

School of Mathematical Sciences, Rochester Institute of Technology, Rochester, New York 14623, USA.

Reentrant electrical scroll waves have been shown to underlie many cardiac arrhythmias, but the inability to observe locations away from the heart surfaces and the restriction of observations to only one or two state variables have made understanding arrhythmia mechanisms challenging. Recently, we showed that data assimilation from spatiotemporally sparse surrogate observations could be used to reconstruct a reliable time series of state estimates of reentrant cardiac electrical waves including unobserved variables in one and three spatial dimensions. However, real cardiac tissue is unlikely to be described accurately by mathematical models because of errors in model formulation and parameterization as well as intrinsic but poorly described spatial heterogeneity of electrophysiological properties in the heart. Read More

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http://dx.doi.org/10.1063/1.4999603DOI Listing
September 2017
5 Reads

Memory in a fractional-order cardiomyocyte model alters properties of alternans and spontaneous activity.

Chaos 2017 Sep;27(9):093904

Virginia Commonwealth University, 401 West Main Street, Richmond, Virginia 23284, USA.

Cardiac memory is the dependence of electrical activity on the prior history of one or more system state variables, including transmembrane potential (V), ionic current gating, and ion concentrations. While prior work has represented memory either phenomenologically or with biophysical detail, in this study, we consider an intermediate approach of a minimal three-variable cardiomyocyte model, modified with fractional-order dynamics, i.e. Read More

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http://dx.doi.org/10.1063/1.4999351DOI Listing
September 2017
3 Reads

Alternans promotion in cardiac electrophysiology models by delay differential equations.

Chaos 2017 Sep;27(9):093915

School of Mathematical Sciences, Rochester Institute of Technology, Rochester, NY 14623, USA.

Cardiac electrical alternans is a state of alternation between long and short action potentials and is frequently associated with harmful cardiac conditions. Different dynamic mechanisms can give rise to alternans; however, many cardiac models based on ordinary differential equations are not able to reproduce this phenomenon. A previous study showed that alternans can be induced by the introduction of delay differential equations (DDEs) in the formulations of the ion channel gating variables of a canine myocyte model. Read More

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http://dx.doi.org/10.1063/1.4999471DOI Listing
September 2017
6 Reads

Double atrial potentials in left-sided accessory pathways are associated with paroxysmal atrial fibrillation.

J Cardiovasc Electrophysiol 2018 Jan 11;29(1):22-29. Epub 2017 Oct 11.

Department of Statistic & Computers, University of Medical Sciences, Poznań, Poland.

Introduction: Muscular connections between the coronary sinus (CS) and left atrium probably impact distribution of electrical activity. Double atrial potentials (DP) may be their presentation. The aim was to investigate the presence of DP in CS recordings during atrioventricular reentrant tachycardia (AVRT) and its contribution to the occurrence of paroxysmal atrial fibrillation (AF). Read More

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http://dx.doi.org/10.1111/jce.13347DOI Listing
January 2018
7 Reads

Ca/calmodulin-dependent kinase II-dependent regulation of atrial myocyte late Na current, Ca cycling, and excitability: a mathematical modeling study.

Am J Physiol Heart Circ Physiol 2017 Dec 25;313(6):H1227-H1239. Epub 2017 Aug 25.

The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center , Columbus, Ohio.

Atrial fibrillation (AF) affects more than three million people per year in the United States and is associated with high morbidity and mortality. Both electrical and structural remodeling contribute to AF, but the molecular pathways underlying AF pathogenesis are not well understood. Recently, a role for Ca/calmodulin-dependent protein kinase II (CaMKII) in the regulation of persistent "late" Na current ( I) has been identified. Read More

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http://dx.doi.org/10.1152/ajpheart.00185.2017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5814646PMC
December 2017
10 Reads

Automatic detection of T wave alternans using tensor decompositions in multilead ECG signals.

Physiol Meas 2017 Jul 26;38(8):1513-1528. Epub 2017 Jul 26.

KU Leuven, Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics, Leuven, Belgium. IMEC, Leuven, Belgium.

Objective: T wave alternans (TWA) is a promising non-invasive risk stratification tool for sudden cardiac death which can be detected from surface ECG. This paper proposes a novel method to automatically detect TWA based on tensor decomposition methods.

Approach: Two different tensor decomposition approaches are examined and compared, namely canonical polyadic decomposition and the more generalized variation PARAFAC2 which allows the T waves to shift in time. Read More

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http://dx.doi.org/10.1088/1361-6579/aa7876DOI Listing
July 2017
8 Reads

Risk stratification personalised model for prediction of life-threatening ventricular tachyarrhythmias in patients with chronic heart failure.

Kardiol Pol 2017 ;75(7):682-688

Republican Scientific and Practical Centre of Cardiology, Minsk, Belarus, Belarus.

Background: The development of prognostic factors of life-threatening ventricular tachyarrhythmias (VTA) and sudden cardiac death (SCD) continues to maintain its priority and relevance in cardiology. The development of a method of personalised prognosis based on multifactorial analysis of the risk factors associated with life-threatening heart rhythm disturbances is considered a key research and clinical task.

Aim: To design a prognostic and mathematical model to define personalised risk for life-threatening VTA in patients with chronic heart failure (CHF). Read More

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http://dx.doi.org/10.5603/KP.a2017.0060DOI Listing
July 2017
8 Reads

Loss of MD1 exacerbates pressure overload-induced left ventricular structural and electrical remodelling.

Sci Rep 2017 07 11;7(1):5116. Epub 2017 Jul 11.

Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, PR China.

Myeloid differentiation protein 1 (MD1) has been implicated in numerous pathophysiological processes, including immune regulation, obesity, insulin resistance, and inflammation. However, the role of MD1 in cardiac remodelling remains incompletely understood. We used MD1-knockout (KO) mice and their wild-type littermates to determine the functional significance of MD1 in the regulation of aortic banding (AB)-induced left ventricular (LV) structural and electrical remodelling and its underlying mechanisms. Read More

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http://dx.doi.org/10.1038/s41598-017-05379-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5505950PMC
July 2017
20 Reads

CaMKII Activation Promotes Cardiac Electrical Remodeling and Increases the Susceptibility to Arrhythmia Induction in High-fat Diet-Fed Mice With Hyperlipidemia Conditions.

J Cardiovasc Pharmacol 2017 Oct;70(4):245-254

*Department of Cardiology, Renming Hospital of Wuhan University, Wuhan, PR China; †Cardiovascular Research Institute, Wuhan University, Wuhan, PR China; and ‡Huei Key Laboratory of Cardiology, Wuhan, PR China.

Background: Obesity/hyperlipidemia is closely related to both atrial and ventricular arrhythmias. CaMKII, a multifunctional serine/threonine kinase, has been involved in cardiac arrhythmias of different etiologies. However, its role in obesity/hyperlipidemia-related cardiac arrhythmia is unexplored. Read More

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http://dx.doi.org/10.1097/FJC.0000000000000512DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5642343PMC
October 2017
7 Reads

β-Adrenergic receptor stimulation inhibits proarrhythmic alternans in postinfarction border zone cardiomyocytes: a computational analysis.

Am J Physiol Heart Circ Physiol 2017 Aug 26;313(2):H338-H353. Epub 2017 May 26.

Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands.

The border zone (BZ) of the viable myocardium adjacent to an infarct undergoes extensive autonomic and electrical remodeling and is prone to repolarization alternans-induced cardiac arrhythmias. BZ remodeling processes may promote or inhibit Ca and/or repolarization alternans and may differentially affect ventricular arrhythmogenesis. Here, we used a detailed computational model of the canine ventricular cardiomyocyte to study the determinants of alternans in the BZ and their regulation by β-adrenergic receptor (β-AR) stimulation. Read More

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http://dx.doi.org/10.1152/ajpheart.00094.2017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5582914PMC
August 2017
3 Reads

Optical Mapping Approaches on Muscleblind-Like Compound Knockout Mice for Understanding Mechanistic Insights Into Ventricular Arrhythmias in Myotonic Dystrophy.

J Am Heart Assoc 2017 Apr 17;6(4). Epub 2017 Apr 17.

Department of Neurology, Chang Gung Memorial Hospital, Keelung, Taiwan

Background: Cardiac arrhythmias are common causes of death in patients with myotonic dystrophy (dystrophia myotonica [DM]). Evidence shows that atrial tachyarrhythmia is an independent risk factor for sudden death; however, the relationship is unclear.

Methods And Results: Control wild-type ( ) and DM mutant ( ) mice were generated by crossing double heterozygous knockout ( ) mice. Read More

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http://dx.doi.org/10.1161/JAHA.116.005191DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5533016PMC
April 2017
5 Reads

Pseudoelectrical alternans during supraventricular tachycardia.

Turk J Emerg Med 2017 Mar 13;17(1):32-33. Epub 2017 Jan 13.

University of South Florida, FGTBA and TEAMHealth, Tampa, FL, USA.

We present a case of pseudoelectrical alternans occurring during supraventricular tachycardia. Read More

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http://dx.doi.org/10.1016/j.tjem.2016.11.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5357114PMC
March 2017
2 Reads

[The Myocardial Sleeves of the Pulmonary Veins: Potential Implications For Atrial Fibrillation].

Kardiologiia 2017 Feb;57(2):34-39

Institute of Experimental Cardiology of Russian Cardiology Research and Production Complex, Moscow, Russia.

Pulmonary veins (PVs) are thought to play an important role in the initiation of atrial fibrillation. However, systematic microelectrode studies from different regions of the left atria and PV myocardium remain limited.

Methods And Results: A 2-microelectrode technique was used to characterize electrophysiological properties of rat left atrial and PV myocardium, at baseline and during electrical stimulation. Read More

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February 2017
6 Reads

Pro-arrhythmic effect of heart rate variability during periodic pacing.

Conf Proc IEEE Eng Med Biol Soc 2016 08;2016:149-152

Clinically, healthy hearts have been associated with a high ventricular heart rate variability (HRV) while diseased hearts have been known to exhibit low ventricular HRV. Hence, low HRV is suggested to be a marker of cardiac ventricular arrhythmias. Over the past few years, there has been considerable amount of interest in incorporating HRV in pacing to emulate healthy heart conditions and re-stabilize the electrical activity in diseased hearts. Read More

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http://dx.doi.org/10.1109/EMBC.2016.7590662DOI Listing
August 2016
3 Reads

Electrophysiological Twisting: Electrical Alternans in Congenital Dilated Cardiomyopathy.

Circ Arrhythm Electrophysiol 2017 02;10(2)

From the Division of Cardiology, Department of Pediatrics, Dalhousie University, IWK Heart Centre, Halifax, Nova Scotia, Canada

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http://dx.doi.org/10.1161/CIRCEP.116.004953DOI Listing
February 2017
5 Reads

The E23K variant of the Kir6.2 subunit of the ATP-sensitive potassium channel increases susceptibility to ventricular arrhythmia in response to ischemia in rats.

Int J Cardiol 2017 Apr 4;232:192-198. Epub 2017 Jan 4.

Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China; Hubei Key Laboratory of Cardiology, Wuhan 430060, China. Electronic address:

Background: The E23K variant of the Kir6.2 subunit of the ATP-sensitive potassium (KATP) channel has been implicated in cardiac remodeling. However, the effects of E23K variant on ventricular electrophysiology and arrhythmogenesis remain unclear. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S01675273173004
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http://dx.doi.org/10.1016/j.ijcard.2017.01.022DOI Listing
April 2017
20 Reads

Increased beat-to-beat T-wave variability in myocardial infarction patients.

Biomed Tech (Berl) 2018 Mar;63(2):123-130

Department of Electrical and Computer Engineering, Ryerson University, Toronto, Canada.

The purpose of this study was to investigate the beat-to-beat variability of T-waves (TWV) and to assess the diagnostic capabilities of T-wave-based features for myocardial infarction (MI). A total of 148 recordings of standard 12-lead electrocardiograms (ECGs) from 79 MI patients (22 females, mean age 63±12 years; 57 males, mean age 57±10 years) and 69 recordings from healthy subjects (HS) (17 females, 42±18 years; 52 males, 40±13 years) were studied. For the quantification of beat-to-beat QT intervals in ECG signal, a template-matching algorithm was applied. Read More

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http://dx.doi.org/10.1515/bmt-2015-0186DOI Listing
March 2018
8 Reads

Mechanisms of arrhythmogenesis related to calcium-driven alternans in a model of human atrial fibrillation.

Sci Rep 2016 11 4;6:36395. Epub 2016 Nov 4.

Johns Hopkins University, Department of Biomedical Engineering, Baltimore, MD, 21218, USA.

The occurrence of atrial fibrillation (AF) is associated with progressive changes in the calcium handling system of atrial myocytes. Calcium cycling instability has been implicated as an underlying mechanism of electrical alternans observed in patients who experience AF. However, the extent to which calcium-induced alternation of electrical activity in the atria contributes to arrhythmogenesis is unknown. Read More

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http://dx.doi.org/10.1038/srep36395DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5095679PMC
November 2016
8 Reads

Local Electrical Dyssynchrony during Atrial Fibrillation: Theoretical Considerations and Initial Catheter Ablation Results.

PLoS One 2016 25;11(10):e0164236. Epub 2016 Oct 25.

Department of Cardiology-Electrophysiology, University Hospital Hamburg, University Heart Center, Hamburg, Germany.

Background: Electrogram-based identification of the regions maintaining persistent Atrial Fibrillation (AF) is a subject of ongoing debate. Here, we explore the concept of local electrical dyssynchrony to identify AF drivers.

Methods And Results: Local electrical dyssynchrony was calculated using mean phase coherence. Read More

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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0164236PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5079563PMC
June 2017
25 Reads

Cardiac dynamics: Alternans and arrhythmogenesis.

J Arrhythm 2016 Oct 28;32(5):411-417. Epub 2016 Mar 28.

Faculty of Medicine, Imperial College London, SW7 2AZ London, UK.

Pre-existing heterogeneities present in cardiac tissue are essential for maintaining the normal electrical and mechanical functions of the heart. Exacerbation of such heterogeneities or the emergence of dynamic factors can produce repolarization alternans, which are beat-to-beat alternations in the action potential time course. Traditionally, this was explained by restitution, but additional factors, such as cardiac memory, calcium handling dynamics, refractory period restitution, and mechano-electric feedback, are increasingly recognized as the underlying causes. Read More

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http://dx.doi.org/10.1016/j.joa.2016.02.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5063258PMC
October 2016
6 Reads

Nonlinear physics of electrical wave propagation in the heart: a review.

Rep Prog Phys 2016 09 12;79(9):096601. Epub 2016 Aug 12.

Physikalisch-Technische Bundesanstalt, Abbestr. 2-12 10587, Berlin, Germany. Department of Physics, Universitat Politècnica de Catalunya, Av. Dr. Marañón 44, E-08028 Barcelona, Spain.

The beating of the heart is a synchronized contraction of muscle cells (myocytes) that is triggered by a periodic sequence of electrical waves (action potentials) originating in the sino-atrial node and propagating over the atria and the ventricles. Cardiac arrhythmias like atrial and ventricular fibrillation (AF,VF) or ventricular tachycardia (VT) are caused by disruptions and instabilities of these electrical excitations, that lead to the emergence of rotating waves (VT) and turbulent wave patterns (AF,VF). Numerous simulation and experimental studies during the last 20 years have addressed these topics. Read More

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http://dx.doi.org/10.1088/0034-4885/79/9/096601DOI Listing
September 2016
4 Reads