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Junctional Rhythm

Hideyuki Hasebe, Akira Takanohashi, Kazuaki Shirota, Hajime Nakamura
Atrioventricular (AV) block and pseudoaneurysm of the mitral-aortic intervalvular fibrosa (P-MAIVF) are rare complications of infective endocarditis (IE). A 72-year-old man with severe aortic stenosis was hospitalized due to IE. After admission, intermittent AV block and P-MAIVF were noted. Interestingly, an accelerated junctional rhythm was observed during the process of AV block resolution. Elective surgery, which included patch closure of the fistula and replacement of the aortic valve, was successfully performed...
2016: Internal Medicine
Patrycja Orlowska-Feuer, Jagoda S Jeczmien-Lazur, Hanna J Szkudlarek, Marian H Lewandowski
A subpopulation of olivary pretectal nucleus (OPN) neurons fire action potentials in a rhythmic manner with an eruption of activity occurring approximately every two minutes. These infra-slow oscillations depend critically on functional retinal input and are subject to modulation by light. Interestingly, the activity of photoreceptors is necessary for the emergence of the rhythm and while classic photoreceptors (rods and cones) are necessary in darkness and dim light, melanopsin photoreceptors are indispensable in bright light...
September 28, 2016: Neuroscience
Amy L Brewster, Kyle Marzec, Alexandria Hairston, Marvin Ho, Anne E Anderson, Yi-Chen Lai
OBJECTIVES: A myriad of acute and chronic cardiac alterations are associated with status epilepticus (SE) including increased sympathetic tone, rhythm and ventricular repolarization disturbances. Despite these observations, the molecular processes underlying SE-associated myocardial remodeling remain to be identified. Here we determined early SE-associated myocardial electrical and molecular alterations using a model of SE and acquired epilepsy. METHODS: We performed electrocardiography (ECG) assessments in rats beginning at 2 weeks following kainate-induced SE, and calculated short-term variability (STV) of the corrected QT intervals (QTc) as a marker of ventricular stability...
August 24, 2016: Epilepsia
Susana Cañón, Ricardo Caballero, Adela Herraiz-Martínez, Marta Pérez-Hernández, Begoña López, Felipe Atienza, José Jalife, Leif Hove-Madsen, Eva Delpón, Antonio Bernad
microRNAs (miR) have considerable potential as therapeutic tools in cardiac diseases. Alterations in atrial miR are involved in the development of atrial fibrillation (AF), but the molecular mechanism underlying their contribution to atrial remodeling in chronic atrial fibrillation (CAF) is only partially understood. Here we used miR array to analyze the miR profile of atrial biopsies from sinus rhythm (SR) and CAF patients. qRT-PCR identified a distinctive CAF-miR signature and described conserved miR-208b upregulation in human and ovine AF atrial tissue...
August 18, 2016: Journal of Molecular and Cellular Cardiology
Natale Daniele Brunetti, Pier Luigi Pellegrino, Girolamo D'Arienzo, Rafel Sai, Luigi Ziccardi, Francesco Santoro, Antonio Gaglione, Matteo Di Biase
We report the case of a 38-year-old woman with history of syncope and polymorphic ventricular tachycardia; tachycardia was inducible at exercise stress test, not at electrophysiologic study. Phases of QT prolongation were found at ambulatory electrocardiogram monitoring. The woman came to our attention for periodic control of implantable loop recorder. Rest electrocardiogram at admission unexpectedly showed sinus bradycardia, junctional rhythm, and ventricular premature beats. Furthermore, loop recorder control revealed a short run of bidirectional tachycardia, not associated with syncope...
July 28, 2016: Journal of Electrocardiology
Ammar M Killu, Erin A Fender, Abhishek J Deshmukh, Thomas M Munger, Philip Araoz, Peter A Brady, Yong-Mei Cha, Douglas L Packer, Paul A Friedman, Samuel J Asirvatham, Peter A Noseworthy, Siva K Mulpuru
BACKGROUND: Many patients with atrial fibrillation (AF) or atrial flutter (Aflutter) have concomitant sinus node dysfunction (SND). Ablation may result in injury to the sinus node complex or its blood supply resulting in sinus arrest and need for temporary pacing. We sought to characterize patients who develop acute SND (ASND) during/immediately after AF/Aflutter ablation. METHODS: We performed a retrospective analysis of AF/Aflutter ablation patients between January 1, 2010 and February 28, 2015 to characterize those who required temporary pacemaker (TPM) implantation due to ASND (sinus arrest, sinus bradycardia <40 beats/min, or junctional rhythm with hemodynamic compromise) following atrial ablation...
October 2016: Pacing and Clinical Electrophysiology: PACE
Rengasayee Veeraraghavan, Joyce Lin, James P Keener, Robert Gourdie, Steven Poelzing
It was recently demonstrated that cardiac sodium channels (Nav1.5) localized at the perinexus, an intercalated disc (ID) nanodomain associated with gap junctions (GJ), may contribute to electrical coupling between cardiac myocytes via an ephaptic mechanism. Impairment of ephaptic coupling by acute interstitial edema (AIE)-induced swelling of the perinexus was associated with arrhythmogenic, anisotropic conduction slowing. Given that Kir2.1 has also recently been reported to localize at intercalated discs, we hypothesized that Kir2...
October 2016: Pflügers Archiv: European Journal of Physiology
Gwang Sil Kim, Jae-Sun Uhm, Tae-Hoon Kim, Hancheol Lee, Junbeom Park, Jin-Kyu Park, Boyoung Joung, Hui-Nam Pak, Moon-Hyoung Lee
BACKGROUND: This study aimed to determine the risk of thromboembolic events in patients with junctional bradycardia(JB). METHODS: We retrospectively reviewed electrocardiograms(ECGs) for 380,682 patients. Those with JB on an ECG at least twice over a ≥3-month interval were included for analysis. We additionally included 138 CHADS2 score-matched patients(age, 68.4 ± 15.7 years; male, 52.2%) in sinus rhythm as a control group. Between the JB patients(with or without retrograde P wave) and controls, we compared incidences of ischemic stroke and a composite of ischemic stroke, renal infarction, ischemic colitis, acute limb ischemia, and pulmonary embolism...
2016: BMC Neurology
Renata Bocian, Bartosz Caban, Paulina Kłos-Wojtczak, Jan Konopacki, Tomasz Kowalczyk
Data obtained in in vitro experiments and urethane anaesthetized animals have revealed that the mechanisms responsible for the generation of hippocampal cholinergic theta rhythm are specifically affected by the administration of broad spectrum gap junctions (GJs) blocker - carbenoxolone (CBX). The aim of this study was to examine the effect of GJs modulation on the production of posterior hypothalamic theta. Specifically, we were interested in evaluating whether CBX could attenuate the theta rhythm recorded from the supramammillary nucleus and posterior hypothalamic nuclei, in both in vitro and in vivo preparations...
September 2016: European Journal of Neuroscience
Chien-Jung Chang, Chen-Chuan Cheng, Yao-Chang Chen, Yu-Hsun Kao, Shih-Ann Chen, Yi-Jen Chen
BACKGROUND: Gap junction (GJ) dysfunctions predispose cardiac tissues to various arrhythmias. Sinoatrial node (SAN) and pulmonary veins (PVs) are closely related atrial dysrhythmia. This study evaluated whether GJ modifications modulate SAN and PVs electrical activities. METHODS: Conventional microelectrodes were used to record action potentials in isolated rabbit SAN, PVs, and connected PV-SAN tissue preparations before and after heptanol (GJ inhibitor) and PQ1 (GJ enhancer) administration with and without isoproterenol...
October 15, 2016: International Journal of Cardiology
Steven D Verba, Brock T Jensen, Jeffrey S Lynn
OBJECTIVE: Deer hunting includes various stimuli resulting in augmented sympathetic activity, increased heart rate (HR) response, and rhythm changes. Collectively, these superimposed stresses may increase an individual's risk for cardiovascular events. We undertook this study to evaluate HR and rhythm responses in multiple phases of deer hunting in men and women with and without cardiovascular disease (CVD). METHODS: Nineteen participants age 38.3 ± 13.8 years (mean ± SD) with body mass index 29...
September 2016: Wilderness & Environmental Medicine
David Forsberg, Zachi Horn, Evangelia Tserga, Erik Smedler, Gilad Silberberg, Yuri Shvarev, Kai Kaila, Per Uhlén, Eric Herlenius
Inflammation-induced release of prostaglandin E2 (PGE2) changes breathing patterns and the response to CO2 levels. This may have fatal consequences in newborn babies and result in sudden infant death. To elucidate the underlying mechanisms, we present a novel breathing brainstem organotypic culture that generates rhythmic neural network and motor activity for 3 weeks. We show that increased CO2 elicits a gap junction-dependent release of PGE2. This alters neural network activity in the preBötzinger rhythm-generating complex and in the chemosensitive brainstem respiratory regions, thereby increasing sigh frequency and the depth of inspiration...
2016: ELife
William N Evans, Ruben J Acherman, Humberto Restrepo
We hypothesized that normal sinus rhythm-sinus bradycardia is common in young children following extracardiac Fontan. After excluding patients with sinus pauses, junctional rhythm, tachy-brady syndrome, frequent ectopics, or ectopic atrial rhythm, we found an ambulatory 24-h Holter monitor average heart rate of 78 ± 12 beats per minute (bpm) in 33 post-extracardiac Fontan children with a median age of 6 years (5-10). A 24-h average heart rate of 78 ± 12 bpm is statistically significantly lower than a 24-h average heart rate value of 90 ± 10 bpm derived from a similarly aged control population (p < 0...
October 2016: Pediatric Cardiology
Rohit Rao, Qian Yang, Mehmet A Orman, Francois Berthiaume, Marianthi G Ierapetritou, Ioannis P Androulakis
Circadian rhythms play an important role in maintaining homeostasis and solid organ function. The purpose of this study is to assess the implications of burn injury in rats on the underlying circadian patterns of gene expression in liver. Circadian-regulated genes and burn-induced genes were identified by applying consensus clustering methodology to temporally differentially expressed probe sets obtained from burn and sham-burn data sets. Of the liver specific genes which we hypothesize that exhibit circadian rhythmicity, 88% are not differentially expressed following the burn injury...
2016: International Journal of Burns and Trauma
Jana-Katharina Dieks, Sophia Klehs, Matthias J Müller, Thomas Paul, Ulrich Krause
BACKGROUND: Treatment of congenital junctional ectopic tachycardia (JET) is often challenging. In the majority of patients affected, a combination of ≥2 antiarrhythmic drugs is required for JET control. OBJECTIVE: The purpose of this study was to assess the efficacy and safety of adjunctive ivabradine therapy for pediatric congenital JET. METHODS: Since January 2015, 5 consecutive patients aged 10 days to 3.5 years (median 8 weeks) were treated with adjunctive ivabradine for congenital JET...
June 2016: Heart Rhythm: the Official Journal of the Heart Rhythm Society
Iwanari Kawamura, Rintaro Hojo, Seiji Fukamizu
INTRODUCTION: Duplication of the left innominate vein is a rare systemic venous anomaly defined as the coexistence of a retroaortic innominate vein and a normally positioned left innominate vein. We describe a successful case of pacemaker implantation in a patient with duplication of the left innominate vein via a retroaortic innominate vein. CASE DESCRIPTION: A 70-year-old mentally challenged man was admitted to our hospital because of bradycardia and an altered state of consciousness...
2016: SpringerPlus
Catarina Vieira, Andre Santa Cruz, Carina Arantes, Sérgia Rocha
A 73-year-old woman was admitted to the emergency room due to sudden-onset dyspnoea, altered mental status and haemodynamic instability. ECG showed a junctional rhythm, T-wave inversion in I, aVL and V2-V6 (present in a previous ECG), and no ST/T changes in the right precordial leads. Transthoracic echocardiography, however, revealed a severe depression of global systolic function of right ventricle with akinesia of free wall and a normal left ventricular function. Coronary angiography showed an occlusion of the proximal segment of the right coronary artery, which was treated with balloon angioplasty, and a chronic lesion of the anterior descending artery...
2016: BMJ Case Reports
Anthony Batte, Peter Lwabi, Sulaiman Lubega, Sarah Kiguli, Violette Nabatte, Charles Karamagi
BACKGROUND: In Uganda, few children with congenital heart diseases (CHD) benefit from early corrective cardiac surgery. These children are at high risk of developing heart failure and electrolyte imbalances; factors which increase their risk of developing arrhythmias. This study aimed to determine the prevalence and factors associated with arrhythmias among children with congenital heart diseases receiving care at Mulago Hospital. METHODS: This was a cross-sectional study carried out from August 2013 to March 2014 at Mulago Hospital...
2016: BMC Cardiovascular Disorders
Vikas Kalra, Lynne Foreman, Deepak Bhakta
No abstract text is available yet for this article.
August 2016: Pacing and Clinical Electrophysiology: PACE
Andrew Prendergast, Claire Wyart
A new study has found that zebrafish motor neurons can contribute to the generation of locomotor rhythms by feedback modulation of their premotor interneurons via gap junctions.
March 21, 2016: Current Biology: CB
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