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https://www.readbyqxmd.com/read/29017652/-hydrogen-can-alleviate-post-cardiac-arrest-myocardium-injury-in-rabbits
#1
Jingao Wang, Jiyan Lin, Minwei Zhang, Yujing He, Xiaowen Pan, Chengbin Yang, Dongmei Cai
OBJECTIVE: To investigate the effects of hydrogen (H2) on myocardium injury post-cardiac arrest (CA) in rabbits. METHODS: Sixty New Zealand rabbits were randomly divided into H2 treatment group (n = 30) and control group (n = 30) by random number table. The rabbit CA model was established by means of electrical stimulation of external membrane, both groups were mechanically ventilated. Cardiopulmonary resuscitation (CPR) was performed after 6 minutes of nonintervention, and stopped after restoration of spontaneous circulation (ROSC)...
October 2017: Zhonghua Wei Zhong Bing Ji Jiu Yi Xue
https://www.readbyqxmd.com/read/28972668/wenxin-keli-diminishes-ca-2-overload-induced-by-hypoxia-reoxygenation-in-cardiomyocytes-through-inhibiting-inal-and-ical
#2
Antao Luo, Zhipei Liu, Zhenzhen Cao, Jie Hao, Lin Wu, Chen Fu, Mengliu Zeng, Wanzhen Jiang, Peihua Zhang, Buchang Zhao, Tao Zhao, Jing Zhao, Jihua Ma
BACKGROUND: An increase in the late sodium current (INaL ) causes intracellular Na(+) overload and subsequently intracellular Ca(2+) ([Ca(2+) ]i ) overload via the stimulated reverse Na(+) -Ca(2+) exchange (NCX). Wenxin Keli (WXKL) is an effective antiarrhythmic Chinese herb extract, but the underlying mechanisms are unclear. METHODS AND RESULTS: The INaL , NCX current (INCX ), L-type Ca(2+) current (ICaL ) and action potentials (APs) were recorded using the whole-cell patch-clamp technique in rabbit ventricular myocytes...
October 3, 2017: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/28964134/extremes-of-fractional-noises-a-model-for-the-timings-of-arrhythmic-heart-beats-in-post-infarction-patients
#3
Annette Witt, Frithjof Ehlers, Stefan Luther
We have analyzed symbol sequences of heart beat annotations obtained from 24-h electrocardiogram recordings of 184 post-infarction patients (from the Cardiac Arrhythmia Suppression Trial database, CAST). In the symbol sequences, each heart beat was coded as an arrhythmic or as a normal beat. The symbol sequences were analyzed with a model-based approach which relies on two-parametric peaks over the threshold (POT) model, interpreting each premature ventricular contraction (PVC) as an extreme event. For the POT model, we explored (i) the Shannon entropy which was estimated in terms of the Lempel-Ziv complexity, (ii) the shape parameter of the Weibull distribution that best fits the PVC return times, and (iii) the strength of long-range correlations quantified by detrended fluctuation analysis (DFA) for the two-dimensional parameter space...
September 2017: Chaos
https://www.readbyqxmd.com/read/28964108/stochastic-spontaneous-calcium-release-events-and-sodium-channelopathies-promote-ventricular-arrhythmias
#4
Fernando O Campos, Yohannes Shiferaw, Edward J Vigmond, Gernot Plank
Premature ventricular complexes (PVCs), the first initiating beats of a variety of cardiac arrhythmias, have been associated with spontaneous calcium release (SCR) events at the cell level. However, the mechanisms underlying the degeneration of such PVCs into arrhythmias are not fully understood. The objective of this study was to investigate the conditions under which SCR-mediated PVCs can lead to ventricular arrhythmias. In particular, we sought to determine whether sodium (Na(+)) current loss-of-function in the structurally normal ventricles provides a substrate for unidirectional conduction block and reentry initiated by SCR-mediated PVCs...
September 2017: Chaos
https://www.readbyqxmd.com/read/28958795/heart-rate-turbulence-after-ventricular-premature-beats-in-healthy-doberman-pinschers-and-those-with-dilated-cardiomyopathy
#5
J D Harris, C J L Little, J M Dennis, M W Patteson
OBJECTIVES: To describe the measurement of heart rate turbulence (HRT) after ventricular premature beats and compare HRT in healthy Doberman pinschers and those with dilated cardiomyopathy (DCM), with and without congestive heart failure (CHF). ANIMALS: Sixty-five client-owned Dobermans: 20 healthy (NORMAL), 31 with preclinical DCM and 14 with DCM and CHF (DCM + CHF). METHODS: A retrospective study of data retrieved from clinical records and ambulatory ECG (Holter) archives, including data collected previously for a large-scale prospective study of Dobermans with preclinical DCM...
September 25, 2017: Journal of Veterinary Cardiology: the Official Journal of the European Society of Veterinary Cardiology
https://www.readbyqxmd.com/read/28952932/localization-of-origins-of-premature-ventricular-contraction-by-means-of-convolutional-neural-network-from-12-lead-ecg
#6
Ting Yang, Long Yu, Qi Jin, Liqun Wu, Bin He
OBJECTIVE: This paper proposes a novel method to localize origins of premature ventricular contractions (PVCs) from 12-lead electrocardiography (ECG) using convolutional neural network (CNN) and a realistic computer heart model. METHODS: The proposed method consists of two CNNs (Segment CNN and Epi-Endo CNN) to classify among ventricular sources from 25 segments and from epicardium (Epi) or endocardium (Endo). The inputs are the full time courses and the first half of QRS complexes of 12-lead ECG, respectively...
September 25, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28952588/a-proof-of-concept-study-simple-and-effective-detection-of-p-and-t-waves-in-arrhythmic-ecg-signals
#7
Mohamed Elgendi, Marianna Meo, Derek Abbott
A robust and numerically-efficient method based on two moving average filters, followed by a dynamic event-related threshold, has been developed to detect P and T waves in electrocardiogram (ECG) signals as a proof-of-concept. Detection of P and T waves is affected by the quality and abnormalities in ECG recordings; the proposed method can detect P and T waves simultaneously through a unique algorithm despite these challenges. The algorithm was tested on arrhythmic ECG signals extracted from the MIT-BIH arrhythmia database with 21,702 beats...
October 17, 2016: Bioengineering
https://www.readbyqxmd.com/read/28940881/diagnostic-yield-of-asymptomatic-arrhythmias-detected-by-mobile-cardiac-outpatient-telemetry-and-autotrigger-looping-event-cardiac-monitors
#8
Wayne M Derkac, Jeffrey R Finkelmeier, Daniel J Horgan, Mathew D Hutchinson
INTRODUCTION: Asymptomatic arrhythmias can have important therapeutic implications in certain patient populations, for example, atrial fibrillation in patients with prior ischemic stroke. We sought to compare the diagnostic yield of two commercially available monitoring systems with automated arrhythmia detection algorithms. METHODS: We queried a large, proprietary database containing rhythm data for patients receiving ambulatory EKG monitoring (BioTelemetry, Malvern, PA, USA)...
September 22, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28894131/ecg-features-and-methods-for-automatic-classification-of-ventricular-premature-and-ischemic-heartbeats-a-comprehensive-experimental-study
#9
Lucie Maršánová, Marina Ronzhina, Radovan Smíšek, Martin Vítek, Andrea Němcová, Lukas Smital, Marie Nováková
Accurate detection of cardiac pathological events is an important part of electrocardiogram (ECG) evaluation and subsequent correct treatment of the patient. The paper introduces the results of a complex study, where various aspects of automatic classification of various heartbeat types have been addressed. Particularly, non-ischemic, ischemic (of two different grades) and subsequent ventricular premature beats were classified in this combination for the first time. ECGs recorded in rabbit isolated hearts under non-ischemic and ischemic conditions were used for analysis...
September 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28884872/the-tip-of-the-muscle-is-a-dominant-location-of-ventricular-ectopy-originating-from-papillary-muscles-in-the-left-ventricle
#10
Petr Peichl, Jakub Baran, Dan Wichterle, Robert Čihák, Tomáš Skála, Bashar Aldhoon, Matevž Jan, Bor Antolič, Josef Kautzner
INTRODUCTION: Frequent ventricular premature complexes (VPCs) may cause symptoms and/or lead to deterioration of LV systolic function. Although frequent VPCs may be abolished by catheter ablation, it may be challenging in case of their origin from the LV papillary muscles (PMs). Our collaborative study aimed to analyze in detail the site of origin and the outcome of ablation. METHODS: Consecutive 34 patients (males: 68%; aged 62 ± 12 years; LV ejection fraction: 50 ± 9%) undergoing catheter ablation of VPCs originating from PMs were included...
September 8, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28863167/the-development-and-validation-of-an-easy-to-use-automatic-qt-interval-algorithm
#11
Ben J M Hermans, Arja S Vink, Frank C Bennis, Luc H Filippini, Veronique M F Meijborg, Arthur A M Wilde, Laurent Pison, Pieter G Postema, Tammo Delhaas
BACKGROUND: To evaluate QT-interval dynamics in patients and in drug safety analysis, beat-to-beat QT-interval measurements are increasingly used. However, interobserver differences, aberrant T-wave morphologies and changes in heart axis might hamper accurate QT-interval measurements. OBJECTIVE: To develop and validate a QT-interval algorithm robust to heart axis orientation and T-wave morphology that can be applied on a beat-to-beat basis. METHODS: Additionally to standard ECG leads, the root mean square (ECGRMS), standard deviation and vectorcardiogram were used...
2017: PloS One
https://www.readbyqxmd.com/read/28858645/simulation-study-of-the-ionic-mechanisms-underlying-torsade-de-pointes-in-a-2d-cardiac-tissue
#12
Ponnuraj Kirthi Priya, M Ramasubba Reddy
BACKGROUND: To understand the ionic mechanism behind the genesis of Torsade de Pointes (TdP) occurring with long QT syndrome 2 (LQTS2) in a remodelled transmural tissue. METHODS: The TP06 model is used to simulate the electrical activity of cells in a 2D transmural ventricular model. LQTS2 is realised by reducing the potassium current (IKr) to 0.5 in each cell. Each cell of the tissue is remodelled by increasing the conductance of calcium current (GCaL). The above two factors make the cells prone to early after depolarizations (EADs) development...
August 24, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28846146/paroxysmal-atrioventricular-block-electrophysiological-mechanism-of-phase-4-conduction-block-in-the-his-purkinje-system-a-comparison-with-phase-3-block
#13
Mohammad Shenasa, Mark E Josephson, Andrew L Wit
BACKGROUND: Paroxysmal atrioventricular (A-V) block is relatively rare, and due to its transient nature, it is often under recognized. It is often triggered by atrial, junctional or ventricular premature beats, and occurs in the presence of a diseased His-Purkinje system (HPS). Here we present a 45-year-old white male who was admitted for observation due to recurrent syncope and near-syncope, who had paroxysmal A-V block. The likely cellular electrophysiological mechanisms(s) of paroxysmal A-V block and its differential diagnosis and management are discussed...
August 28, 2017: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/28836312/premature-ventricular-contraction-induced-concealed-retrograde-penetration-electrocardiographic-manifestations-on-anterograde-ventricular-preexcitation
#14
Damián Longo, Adrian Baranchuk
In patients with manifest anterograde ventricular preexcitation, the electrocardiographic manifestation of the anomalous conduction through the simultaneous conduction over the atrioventricular (AV) node and the accessory pathway ("delta wave"); depends on several factors, the most representative being the conduction velocity over one or another connection. Occasionally, ventricular ectopic beats may present with retrograde penetration over one or both conduction pathways (AV node and/or accessory pathway), impacting on the morphology of the next immediate anterogradely conducted QRS...
August 24, 2017: Annals of Noninvasive Electrocardiology
https://www.readbyqxmd.com/read/28795038/indentation-in-the-right-ventricle-by-an-incomplete-pericardium-on-3-dimensional-reconstructed-computed-tomography
#15
Hak Ju Kim, Jae Gun Kwak
We report the case of a 17-year-old girl who presented with an indentation in the right ventricle caused by an incomplete pericardium on preoperative 3-dimensional reconstructed computed tomography. She was to undergo surgery for a partial atrioventricular septal defect and secundum atrial septal defect. Preoperative electrocardiography revealed occasional premature ventricular beats. We found the absence of the left side of the pericardium intraoperatively, and this absence caused strangulation of the diaphragmatic surface of the right ventricle...
August 2017: Korean Journal of Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/28770871/yield-of-48-hour-holter-monitoring-in-children-with-unexplained-palpitations-and-significance-of-associated-symptoms
#16
Rabbia Aman, Ahmad Usaid Qureshi, Masood Sadiq
OBJECTIVE: To determine the yield of 48-hour Holter monitoring in children with unexplained palpitations and the significance of associated symptoms. METHODS: This descriptive study was conducted at the Children's Hospital and Institute of Child Health, Lahore, Pakistan, from January 1 to December 31, 2015. All children above 5 years of age with history of intermittent palpitations and normal basic cardiovascular workup were enrolled. A 48-hour Holter study was performed using Motara Holter Monitoring System...
July 2017: JPMA. the Journal of the Pakistan Medical Association
https://www.readbyqxmd.com/read/28735831/wenxin-keli-for-ventricular-premature-complexes-with-heart-failure-a-systematic-review-and-meta-analysis-of-randomized-clinical-trials
#17
REVIEW
Min Li, Ruijin Qiu, Guihua Tian, Xiaoyu Zhang, Chengyu Li, Shiqi Chen, Qin Zhang, Hongcai Shang
OBJECTIVE: To evaluate the efficacy and safety of Wenxin Keli (WXKL) alone or combined with Western medicine in treating ventricular premature complexes (VPCs) with heart failure (HF). METHODS: We searched five databases to identify relevant randomized controlled trials (RCTs) published before May 2016. Two review authors independently searched and screened the literature, extracted the data as well as assessed the methodological quality of the included studies by using criteria from the Cochrane Handbook, and analyzed via using Review Manager 5...
August 2017: Complementary Therapies in Medicine
https://www.readbyqxmd.com/read/28735292/pathogenesis-of-hypertrophic-cardiomyopathy-is-mutation-rather-than-disease-specific-a-comparison-of-the-cardiac-troponin-t-e163r-and-r92q-mouse-models
#18
Cecilia Ferrantini, Raffaele Coppini, Josè Manuel Pioner, Francesca Gentile, Benedetta Tosi, Luca Mazzoni, Beatrice Scellini, Nicoletta Piroddi, Annunziatina Laurino, Lorenzo Santini, Valentina Spinelli, Leonardo Sacconi, Pieter De Tombe, Rachel Moore, Jil Tardiff, Alessandro Mugelli, Iacopo Olivotto, Elisabetta Cerbai, Chiara Tesi, Corrado Poggesi
BACKGROUND: In cardiomyocytes from patients with hypertrophic cardiomyopathy, mechanical dysfunction and arrhythmogenicity are caused by mutation-driven changes in myofilament function combined with excitation-contraction (E-C) coupling abnormalities related to adverse remodeling. Whether myofilament or E-C coupling alterations are more relevant in disease development is unknown. Here, we aim to investigate whether the relative roles of myofilament dysfunction and E-C coupling remodeling in determining the hypertrophic cardiomyopathy phenotype are mutation specific...
July 22, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28730712/slow-conduction-through-an-arc-of-block-a-basis-for-arrhythmia-formation-postmyocardial-infarction
#19
Eugene Patterson, Benjamin J Scherlag, Edward J Berbari, Ralph Lazzara
INTRODUCTION: The electrophysiologic basis for characteristic rate-dependent, constant-late-coupled (390 + 54 milliseconds) premature ventricular beats (PVBs) present 4-5 days following coronary artery occlusion were examined in 108 anesthetized dogs. METHODS AND RESULTS: Fractionated/double potentials were observed in injured zone bipolar and composite electrograms at prolonged sinus cycle lengths (1,296 ± 396 milliseconds). At shorter cycle lengths, conduction of the delayed potential decremented, separating from the initial electrogram by a progressively prolonged isoelectric interval...
October 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28717114/the-efficacy-of-isochronal-3d-mapping-based-ablation-of-ventricular-arrhythmia
#20
Masahito Suzuki, Junichi Nitta, Yosuke Hayashi, Kikou Lee, Keita Watanabe, Tatsuhiko Hirao, Nobutaka Kato, Yukihiro Inamura, Akira Sato, Masahiko Goya, Kenzo Hirao, Mitsuaki Isobe
Treatment of ventricular arrhythmias (VAs) commonly involves ablating sites showing electrograms with the earliest activity relative to the VA, but there is no threshold value for prematurity guaranteeing success. Ablation of sites with great prematurity can still result in failure.We hypothesized that isochronal map area (ISCA), derived from isochrones indicating electrogram prematurity, could help identify ablation targets in VA patients, as well as predict outcome. Specifically, we hypothesized that smaller ICSA for a given prematurity value would indicate a shallower arrhythmogenic focus leading to a higher likelihood of successful ablation...
August 3, 2017: International Heart Journal
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