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Sample records for arrhythmias venice 5-8

  1. Arrhythmias

    MedlinePlus

    A change in the heart's normal electrical conduction system can result in an arrhythmia or irregular heartbeat. An arrhythmia can be an abnormally slow heartbeat, or an abnormally fast heartbeat. In ...

  2. Arrhythmia

    MedlinePlus

    An arrhythmia is a problem with the rate or rhythm of your heartbeat. It means that your heart beats ... is called bradycardia. The most common type of arrhythmia is atrial fibrillation, which causes an irregular and ...

  3. Arrhythmia

    MedlinePlus

    ... from the NHLBI on Twitter. What Is an Arrhythmia? Español An arrhythmia (ah-RITH-me-ah) is a problem with ... rate or rhythm of the heartbeat. During an arrhythmia, the heart can beat too fast, too slow, ...

  4. Arrhythmia

    MedlinePlus

    ... beats too quickly, too slowly, or with an irregular pattern. When the heart beats faster than normal, ... of arrhythmia is atrial fibrillation, which causes an irregular and fast heart beat. Many factors can affect ...

  5. [Arrhythmias].

    PubMed

    Misaki, Takuro; Fukahara, Kazuaki

    2004-07-01

    The success of the radiofrequency catheter ablation procedure for most types of supraventricular and ventricular tachycardia largely eliminated the role of surgical therapy of arrhythmias. However, there remains a subset of arrhythmia patients in whom urgent surgical treatments are required. In this review we mention recent developments of the urgent surgical treatment for arrhythmias. In cases with complete atrioventricular (AV) block and ventricular fibrillation which associated with sudden death, temporary cardiac pacing and cardiac defibrillation using direct current (DC) cardioversion must be immediately induced and followed by implantation of permanent cardiac pacemaker or implantable cardioverter defibrillator (ICD), if necessary. In addition to usual cardiac pacing therapy, novel pacing therapy has been developed recently for the patients with symptomatic heart failure. Cardiac resynchronization therapy (CRT) using biventricular pacing is an emerging therapy for improvement of cardiac function in patients with heart failure in association with intraventricular conduction delay. To prevent the sudden death in patients with heart failure, biventricular pacing combined with ICD are also implanted and its efficacy are reported. With the exception of the pacing therapy, curative surgical treatments are limited in drug-refractory atrial fibrillation and ventricular fibrillation/tachycardia after myocardial infarction requiring Dor's type operation. In any case surgical treatment must be performed promptly and suitably with lower invasive methods. PMID:15362552

  6. Venice, Italy

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Four hundred bridges cross the labyrinth of canals that form the 120 islands of Venice, situated in a saltwater lagoon between the mouths of the Po and Piave rivers in northeast Italy. All traffic in the city moves by boat. Venice is connected to the mainland, 4 kilometers (2.5 miles) away, by ferries as well as a causeway for road and rail traffic. The Grand Canal winds through the city for about 3 kilometers (about 2 miles), dividing it into two nearly equal sections. According to tradition, Venice was founded in 452, when the inhabitants of Aquileia, Padua, and several other northern Italian cities took refuge on the islands of the lagoon from the Teutonic tribes invading Italy at that time.

    This image was acquired on December 9, 2001 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    Dr. Anne

  7. [Reperfusion arrhythmias].

    PubMed

    Jurkovicová, O; Cagán, S

    1998-01-01

    Reperfusion arrhythmias originate as a consequence of the complex of cellular and humoral reactions accompanying the opening of coronary artery. As the primary cause of their generation are considered the chemically defined substances that are produced and accumulated in myocardium during reperfusion. The key role is ascribed to free oxygen radicals but of importance are also other substances such as calcium, thrombin, platelet activating factor, inositol triphosphate, angiotensin II and others. These chemical mediators of reperfusion arrhythmias operate as modulators of cellular electrophysiology causing the complex changes at the level of ion channels. It is supposed that in the genesis of reperfusion arrhythmias unlike ischemic arrhytmias operate nonreentrant mechanisms such as abnormal or enhanced automacy and triggered activity due to afterdepolarizations. As a typical reperfusion arrhythmia is considered an early (within 6 hours after start of thrombolysis), frequent (> 30 episodes/hour) and repetitive (occurring during > 3 consecutive hours) accelerated idioventricular rhythm (AIVR). AIVR with such characteristics has a high specificity and positive predictive accuracy but relative low sensitivity as a predictor of reperfusion. Thus, in occurrence of AIVR, recanalization of infarction-related coronary artery is very probable, but in absence of AIVR, reperfusion is still not excluded. The following arrhythmias are regarded also as markers of reperfusion: frequent premature ventricular complexes (> twofold increase in frequency within 90 minutes after the start of thrombolysis), a significant increase of episodes in nonsustained ventricular tachycardia, sinus bradycardia and probably also high-degree atrioventricular blocks. At present, there is no definite evidence, as to whether sustained ventricular tachycardia and especially ventricular fibrillation can be caused by reperfusion. Reperfusion arrhythmias are an important noninvasive marker of successful

  8. Living with an Arrhythmia

    MedlinePlus

    ... from the NHLBI on Twitter. Living With an Arrhythmia Many arrhythmias are harmless. It's common to have an occasional ... heartbeat or mild palpitations . People who have harmless arrhythmias can live healthy lives. They usually don't ...

  9. Spectrum of Fascicular Arrhythmias.

    PubMed

    Sung, Raphael; Scheinman, Melvin

    2016-09-01

    Fascicular arrhythmias encompass a wide spectrum of ventricular arrhythmias that depend on the specialized conduction system of the right and left ventricles. These arrhythmias include premature ventricular complexes, monomorphic ventricular tachycardia, polymorphic ventricular tachycardia, and ventricular fibrillation. These arrhythmias may be organized by mechanism, including intrafascicular reentry, interfascicular reentry, and focal. Mapping and ablation of the fascicular system can result in high cure rates of debilitating and potentially life-threatening arrhythmias. When approaching these arrhythmias, careful consideration of the structure of the His Purkinje system as well as their electrophysiologic properties may help guide even the most complex of arrhythmias. PMID:27521090

  10. Gypsies, Jews, and "The Merchant of Venice."

    ERIC Educational Resources Information Center

    McKendy, Thomas

    1988-01-01

    Shows how looking at Shakespeare's prejudices and their roots, as seen in "The Merchant of Venice," can teach students not only about historical attitudes but also about their own unacknowledged assumptions and stereotypes. (MM)

  11. Prevention and Treatment of Arrhythmia

    MedlinePlus

    ... Pressure High Blood Pressure Tools & Resources Stroke More Prevention & Treatment of Arrhythmia Updated:Sep 2,2016 Do ... Risk for Arrhythmia • Symptoms, Diagnosis & Monitoring of Arrhythmia • Prevention & Treatment of Arrhythmia Introduction Medications Ablation Devices for ...

  12. Children and Arrhythmia

    MedlinePlus

    ... and is at risk for sudden arrhythmias including sudden death. Learn about special considerations for cardiac arrest in ... and is at risk for sudden arrhythmias including sudden death. Learn about special considerations for cardiac arrest in ...

  13. Treating Arrhythmias in Children

    MedlinePlus

    ... and is at risk for sudden arrhythmias including sudden death. Learn about special considerations for cardiac arrest in ... and is at risk for sudden arrhythmias including sudden death. Learn about special considerations for cardiac arrest in ...

  14. How Are Arrhythmias Treated?

    MedlinePlus

    ... Some arrhythmias are treated with a jolt of electricity to the heart. This type of treatment is ... senses a dangerous ventricular arrhythmia, it sends an electric shock to the heart to restore a normal ...

  15. Cardiac arrhythmias in pregnancy.

    PubMed

    Knotts, Robert J; Garan, Hasan

    2014-08-01

    As more women with repaired congenital heart disease survive to their reproductive years and many other women are delaying pregnancy until later in life, a rising concern is the risk of cardiac arrhythmias during pregnancy. Naturally occurring cardiovascular changes during pregnancy increase the likelihood that a recurrence of a previously experienced cardiac arrhythmia or a de novo arrhythmia will occur. Arrhythmias should be thoroughly investigated to determine if there is a reversible etiology, and risks/benefits of treatment options should be fully explored. We discuss the approach to working up and treating various arrhythmias during pregnancy with attention to fetal and maternal risks as well as treatment of fetal arrhythmias. Acute management in stable patients includes close monitoring and intravenous pharmacologic therapy, while DC cardioversion should be used to terminate arrhythmias in hemodynamically unstable patients. Long-term management may require continued oral antiarrhythmic therapy, with particular attention to fetal safety, to prevent complications associated with arrhythmias. PMID:25037518

  16. Predictive simulation of the subsidence of venice.

    PubMed

    Gambolati, G; Gatto, P; Freeze, R A

    1974-03-01

    Land subsidence at Venice is the result of sediment compaction in the unconsolidated, aquifer-aquitard system that underlies the Venetian Lagoon. Compaction is caused by extensive groundwater withdrawals at the nearby industrial port of Marghera. The total subsidence at Venice for the period from 1930 through 1973 has been about 15 centimeters. Predictive simulations with a calibrated mathematical model were hampered by the sparseness of available data, but, as a first estimate, they suggest that, if withdrawals are kept constant in the future as they have been since 1969, about 3 centimeters of further subsidence can be expected. PMID:17780771

  17. Ranolazine in Cardiac Arrhythmia.

    PubMed

    Saad, Marwan; Mahmoud, Ahmed; Elgendy, Islam Y; Richard Conti, C

    2016-03-01

    Ranolazine utilization in the management of refractory angina has been established by multiple randomized clinical studies. However, there is growing evidence showing an evolving role in the field of cardiac arrhythmias. Multiple experimental and clinical studies have evaluated the role of ranolazine in prevention and management of atrial fibrillation, with ongoing studies on its role in ventricular arrhythmias. In this review, we will discuss the pharmacological, experimental, and clinical evidence behind ranolazine use in the management of various cardiac arrhythmias. PMID:26459200

  18. Anger and ventricular arrhythmias

    PubMed Central

    Lampert, Rachel

    2011-01-01

    Purpose of review Although anecdotal evidence has long suggested links between emotion and ventricular arrhythmia, more recent studies have prospectively demonstrated the arrhythmogenic effects of anger, as well as mechanisms underlying these effects. Recent findings Epidemiological studies reveal that psychological stress increases sudden death, as well as arrhythmias, in patients with implantable cardioverter-defibrillators, in populations during emotionally devastating disasters such as earthquake or war. Diary-based studies confirm that anger and other negative emotions can trigger potentially lethal ventricular arrhythmias. Anger alters electrophysiological properties of the myocardium, including T-wave alternans, a measure of heterogeneity of repolarization, suggesting one mechanistic link between emotion and arrhythmia. Pilot studies of behavioral interventions have shown promise in decreasing arrhythmias in patients with implantable cardioverter-defibrillators. Summary Anger and other strong emotions can trigger polymorphic, potentially life-threatening ventricular arrhythmias in vulnerable patients. Through autonomic changes including increased sympathetic activity and vagal withdrawal, anger leads to increases in heterogeneity of repolarization as measured by T-wave alternans, known to be associated with arrhythmogenesis, as well as increasing inducibility of arrhythmia. Further delineation of mechanisms linking anger and arrhythmia, and of approaches to decrease the detrimental effects of anger and other negative emotions on arrhythmogenesis, are important areas of future investigation. PMID:19864944

  19. 6 CFR 5.8 - Business information.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... requirements of Executive Order 12600 (3 CFR, 1988 Comp., p. 235); or (4) The designation made by the submitter... 6 Domestic Security 1 2011-01-01 2011-01-01 false Business information. 5.8 Section 5.8 Domestic... Freedom of Information Act § 5.8 Business information. (a) In general. Business information obtained...

  20. 6 CFR 5.8 - Business information.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... requirements of Executive Order 12600 (3 CFR, 1988 Comp., p. 235); or (4) The designation made by the submitter... 6 Domestic Security 1 2012-01-01 2012-01-01 false Business information. 5.8 Section 5.8 Domestic... Freedom of Information Act § 5.8 Business information. (a) In general. Business information obtained...

  1. 6 CFR 5.8 - Business information.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... requirements of Executive Order 12600 (3 CFR, 1988 Comp., p. 235); or (4) The designation made by the submitter... 6 Domestic Security 1 2014-01-01 2014-01-01 false Business information. 5.8 Section 5.8 Domestic... Freedom of Information Act § 5.8 Business information. (a) In general. Business information obtained...

  2. 6 CFR 5.8 - Business information.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... requirements of Executive Order 12600 (3 CFR, 1988 Comp., p. 235); or (4) The designation made by the submitter... 6 Domestic Security 1 2013-01-01 2013-01-01 false Business information. 5.8 Section 5.8 Domestic... Freedom of Information Act § 5.8 Business information. (a) In general. Business information obtained...

  3. 6 CFR 5.8 - Business information.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... requirements of Executive Order 12600 (3 CFR, 1988 Comp., p. 235); or (4) The designation made by the submitter... 6 Domestic Security 1 2010-01-01 2010-01-01 false Business information. 5.8 Section 5.8 Domestic... Freedom of Information Act § 5.8 Business information. (a) In general. Business information obtained...

  4. Land Subsidence International Symposium held in Venice

    NASA Astrophysics Data System (ADS)

    The Third International Symposium on Land Subsidence was held March 18-25, 1984, in Venice, Italy. Sponsors were the Ground-Water Commission of the International Association of Hydrological Sciences (IAHS), the United Nations Educational, Scientific, and Cultural Organization (UNESCO), the Italian National Research Council (CNR), the Italian Regions of Veneto and Emilia-Romagna, the Italian Municipalities of Venice, Ravenna, and Modena, the Venice Province, and the European Research Office. Cosponsors included the International Association of Hydrogeologists (IAH), the International Society for Soil Mechanics and Foundation Engineering (ISSMFE), and the Association of Geoscientists for International Development (AGID).Organized within the framework of UNESCO's International Hydrological Program, the symposium brought together over 200 international interdisciplinary specialists in the problems of land subsidence due to fluid and mineral withdrawal. Because man's continuing heavy development of groundwater, gas, oil, and minerals is changing the natural regime and thus causing more and more subsiding areas in the world, there had been sufficient new land subsidence occurrence, problems, research, and remedial measures since the 1976 Second International Symposium held in Anaheim, California, to develop a most interesting program of nearly 100 papers from about 30 countries. The program consisted of papers covering case histories of fluid and mineral withdrawal, engineering theory and analysis, karst “sink-hole”-type subsidence, subsidence due to dewatering of organic deposits or due to application of water (hydrocompaction), instrumentation, legal, socioeconomic, and environmental effects of land subsidence, and remedial works.

  5. Is the Venice Lagoon Noisy? First Passive Listening Monitoring of the Venice Lagoon: Possible Effects on the Typical Fish Community.

    PubMed

    Bolgan, Marta; Picciulin, Marta; Codarin, Antonio; Fiorin, Riccardo; Zucchetta, Matteo; Malavasi, Stefano

    2016-01-01

    Three passive listening surveys have been carried out in two of the three Venice lagoon tide inlets and inside the Venice island. The spectral content and the intensity level of the underwater noise as well as the presence or absence of Sciaena umbra and the distribution of its different sound patterns have been investigated in all the recording sites. The passive listening proved to be successful in detecting S. umbra drumming sounds in both Venice lagoon tide inlets. Our results indicate that the spectral content and the level of underwater noise pollution in the Venice lagoon could affect fish acoustic communication. PMID:26610947

  6. Understand Your Risk for Arrhythmia

    MedlinePlus

    ... Tools & Resources Stroke More Understand Your Risk for Arrhythmia Updated:Apr 6,2016 Expected changes in heart ... content was last reviewed on 10/23/2014. Arrhythmia • Home • About Arrhythmia • Why Arrhythmia Matters • Understand Your ...

  7. Devices for Arrhythmia

    MedlinePlus

    ... the heart an electric shock (as with a defibrillator ). For people with recurrent arrhythmias, medical devices such as a pacemaker and implantable cardioverter defibrillator (ICD) can help by continuously monitoring the heart's ...

  8. History of arrhythmias.

    PubMed

    Janse, M J; Rosen, M R

    2006-01-01

    A historical overview is given on the techniques to record the electrical activity of the heart, some anatomical aspects relevant for the understanding of arrhythmias, general mechanisms of arrhythmias, mechanisms of some specific arrhythmias and nonpharmacological forms of therapy. The unravelling of arrhythmia mechanisms depends, of course, on the ability to record the electrical activity of the heart. It is therefore no surprise that following the construction of the string galvanometer by Einthoven in 1901, which allowed high-fidelity recording of the body surface electrocardiogram, the study of arrhythmias developed in an explosive way. Still, papers from McWilliam (1887), Garrey (1914) and Mines (1913, 1914) in which neither mechanical nor electrical activity was recorded provided crucial insights into re-entry as a mechanism for atrial and ventricular fibrillation, atrioventricular nodal re-entry and atrioventricular re-entrant tachycardia in hearts with an accessory atrioventricular connection. The components of the electrocardiogram, and of extracellular electrograms directly recorded from the heart, could only be well understood by comparing such registrations with recordings of transmembrane potentials. The first intracellular potentials were recorded with microelectrodes in 1949 by Coraboeuf and Weidmann. It is remarkable that the interpretation of extracellular electrograms was still controversial in the 1950s, and it was not until 1962 that Dower showed that the transmembrane action potential upstroke coincided with the steep negative deflection in the electrogram. For many decades, mapping of the spread of activation during an arrhythmia was performed with a "roving" electrode that was subsequently placed on different sites on the cardiac surface with a simultaneous recording of another signal as time reference. This method could only provide reliable information if the arrhythmia was strictly regular. When multiplexing systems became available in

  9. Deposition in St. Mark's Basilica of Venice.

    PubMed

    Morabito, E; Zendri, E; Piazza, R; Ganzerla, R; Montalbani, S; Marcoleoni, E; Bonetto, F; Scandella, A; Barbante, C; Gambaro, A

    2013-04-01

    Atmospheric pollutants may cause damage to monuments and historical buildings. Besides air contaminants, soluble salts are also responsible for stone deterioration and decay in outdoor and indoor monuments. The problem of how to conserve works of arts thus requires a deep knowledge of contaminants' concentration and distribution inside buildings. In this work, water-soluble ions inside St. Mark's Basilica in Venice were studied, with the aim of understanding their principal source and distribution inside the building. With the aid of Fourier transform infrared spectroscopy and scanning electron microscopy analysis, the interaction between ions and surface's material was also investigated. Ion chromatographic analysis of depositions highlighted a large amount of "deteriorating agents" such as sulphates and chlorides. A possible source in the innermost area of the basilica has been found for formates and nitrates. On the contrary, a decrease of chloride, from the entrance to the innermost area, has been found, which indicates that the source is outside the building. It is emphasized that different contaminants behave differently on different material, and the effect of pollution inside churches and monuments is not easy to predict. Wood and brick seem to react differently than stone and mortar to the damaging action of salts and pollutants. The present work should be considered a useful tool for the future preservation of St. Mark's Basilica in Venice. PMID:22972617

  10. Mitochondria and Arrhythmias

    PubMed Central

    Yang, Kai-Chien; Bonini, Marcelo G.; Dudley, Samuel C.

    2014-01-01

    Mitochondria are essential to providing ATP thereby satisfying the energy demand of the incessant electrical activity and contractile action of cardiac muscle. Emerging evidence indicates that mitochondrial dysfunction can adversely impact cardiac electrical functioning by impairing the intracellular ion homeostasis and membrane excitability through reduced ATP production and excessive reactive oxidative species (ROS) generation, resulting in increased propensity to cardiac arrhythmias. In this review, the molecular mechanisms linking mitochondrial dysfunction to cardiac arrhythmias are discussed with an emphasis on the impact of increased mitochondrial ROS on the cardiac ion channels and transporters that are critical to maintaining normal electromechanical functioning of the cardiomyocytes. The potential of using mitochondria-targeted antioxidants as a novel anti-arrhythmia therapy is highlighted. PMID:24713422

  11. Hemodynamics in fetal arrhythmia.

    PubMed

    Sonesson, Sven-Erik; Acharya, Ganesh

    2016-06-01

    Fetal arrhythmias are among the few conditions that can be managed in utero. However, accurate diagnosis is essential for appropriate management. Ultrasound-based imaging methods can be used to study fetal heart structure and function noninvasively and help to understand fetal cardiovascular pathophysiology, and they remain the mainstay of evaluating fetuses with arrhythmias in clinical settings. Hemodynamic evaluation using Doppler echocardiography allows the elucidation of the electrophysiological mechanism and helps to make an accurate diagnosis. It can also be used as a tool to understand fetal cardiac pathophysiology, for assessing fetal condition and monitoring the effect of antiarrhythmic treatment. This narrative review describes Doppler techniques that are useful for evaluating fetal cardiac rhythms to refine diagnosis and provides an overview of hemodynamic changes observed in different types of fetal arrhythmia. PMID:26660845

  12. [Alcohol and arrhythmias].

    PubMed

    Pfeiffer, D; Jurisch, D; Neef, M; Hagendorff, A

    2016-09-01

    The effects of alcohol on induction of arrhythmias is dose-dependent, independent of preexisting cardiovascular diseases or heart failure and can affect otherwise healthy subjects. While the probability of atrial fibrillation increases with the alcohol dosage, events of sudden cardiac death are less frequent with low and moderate consumption but occur more often in heavy drinkers with alcoholic cardiomyopathy. Men are first affected at higher dosages of alcohol but women can suffer from arrhythmias at lower dosages. Thromboembolisms and ischemic stroke can occur less often at lower dosages of alcohol; however, hemorrhagic stroke and subarachnoid hemorrhage are increased with higher alcohol dosages. Recognizable protective mechanisms of alcohol with respect to cardiovascular diseases only occur with lower amounts of alcohol of less than 10 g per day. Underlying mechanisms explain these controversial effects. Specific therapeutic options for alcohol-related arrhythmias apart from abstinence from alcohol consumption are not known. PMID:27582366

  13. Fetal and Neonatal Arrhythmias.

    PubMed

    Jaeggi, Edgar; Öhman, Annika

    2016-03-01

    Cardiac arrhythmias are an important aspect of fetal and neonatal medicine. Premature complexes of atrial or ventricular origin are the main cause of an irregular heart rhythm. The finding is typically unrelated to an identifiable cause and no treatment is required. Tachyarrhythmia most commonly relates to supraventricular reentrant tachycardia, atrial flutter, and sinus tachycardia. Several antiarrhythmic agents are available for the perinatal treatment of tachyarrhythmias. Enduring bradycardia may result from sinus node dysfunction, complete heart block and nonconducted atrial bigeminy as the main arrhythmia mechanisms. The management and outcome of bradycardia depend on the underlying mechanism. PMID:26876124

  14. LITERATURE CURRICULUM III--TEST FOR "THE MERCHANT OF VENICE."

    ERIC Educational Resources Information Center

    KITZHABER, ALBERT R.

    THIS TEST--"THE MERCHANT OF VENICE"--WAS DESIGNED BY THE OREGON CURRICULUM STUDY CENTER FOR A NINTH-GRADE LITERATURE CURRICULUM. IT IS INTENDED TO ACCOMPANY CURRICULUM UNITS AVAILABLE AS ED 010 815 AND ED 010 816. (MM)

  15. Exercise and Inherited Arrhythmias.

    PubMed

    Cheung, Christopher C; Laksman, Zachary W M; Mellor, Gregory; Sanatani, Shubhayan; Krahn, Andrew D

    2016-04-01

    Sudden cardiac death (SCD) in an apparently healthy individual is a tragedy that prompts a series of investigations to identify the cause of death and to prevent SCD in potentially at-risk family members. Several inherited channelopathies and cardiomyopathies, including long QT syndrome (LQTS), catecholaminergic polymorphic ventricular cardiomyopathy (CPVT), hypertrophic cardiomyopathy (HCM), and arrhythmogenic right ventricular cardiomyopathy (ARVC) are associated with exercise-related SCD. Exercise restriction has been a historical mainstay of therapy for these conditions. Syncope and cardiac arrest occur during exercise in LQTS and CPVT because of ventricular arrhythmias, which are managed with β-blockade and exercise restriction. Exercise may provoke hemodynamic or ischemic changes in HCM, leading to ventricular arrhythmias. ARVC is a disease of the desmosome, whose underlying disease process is accelerated by exercise. On this basis, expert consensus has erred on the side of caution, recommending rigorous exercise restriction for all inherited arrhythmias. With time, as familiarity with inherited arrhythmia conditions has increased and patients with milder forms of disease are diagnosed, practitioners have questioned the historical rigorous restrictions advocated for all. This change has been driven by the fact that these are often children and young adults who wish to lead active lives. Recent evidence suggests a lower risk of exercise-related arrhythmias in treated patients than was previously assumed, including those with previous symptoms managed with an implantable cardioverter-defibrillator. In this review, we emphasize shared decision making, monitored medical therapy, individual and team awareness of precautions and emergency response measures, and a more permissive approach to recreational and competitive exercise. PMID:26927864

  16. Meeting of World Medical Association in Venice.

    PubMed

    1983-12-10

    Several changes in existing WMA declarations were adopted at the 1983 annual Assembly. The 1948 Declaration of Geneva was amended to indicate respect for human life from the "time of commencement" rather than the previous "time of conception." A determination of when life commences was left open. A new clause was added to the 1964 Declaration on Human Experimentation in General to cover protection of children. Wording emphasizing that the entire brain including the stem must have ceased functioning was added to the WMA position on determining death for purposes of organ transplantation. A document regarding euthanasia was approved and will be released as the Declaration of Venice, 1983. It considers euthanasia to be unacceptable even in cases of incurable illness; however, withholding treatment in order to reduce suffering is stated to be appropriate when the patient or next of kin consents. PMID:11644274

  17. [Arrhythmias during pregnancy].

    PubMed

    Trappe, H-J

    2008-09-01

    Cardiovascular emergencies are rare during pregnancy with an incidence of 0,2-4,0%. Emergencies include arrhythmias, acute coronary syndrome, peripartum cardiomyopathy and hypertensive disorders. Electrical DC-cardioversion with 50-100 Joules is indicated in the acute treatment of arrhythmias in all patients in an unstable hemodynamic state. If 100 J fails higher energies (up to 360 J) will be necessary. In stable supraventricular tachycardia intravenous adenosine is the first choice drug and may safely terminate the arrhythmia. Ventricular premature beats are frequently present during pregnancy and benign in most patients. However, life-threatening ventricular tachyarrhythmias (sustained ventricular tachycardia [VT], ventricular flutter [VFlt], ventricular fibrillation [VF]) were observed less frequently. Electrical DC-cardioversion is necessary in all pregnant women who are in a hemodynamically unstable state and have a life-threatening ventricular tachyarrhythmias. In hemodynamically stable pregnant women the initial therapy with ajmaline, procainamide or lidocaine is indicated. Implantation of a cardioverter-defibrillator is indicated in patients with syncope caused by VT, VF, VFlt or aborted sudden death. PMID:18767007

  18. [Arrhythmias in athlets (author's transl)].

    PubMed

    Degenhardt, H; Jungmann, H

    1978-10-20

    380 athletes in optimal performance were examinated within 10 years between 2 and 13 times (average: 4 times): ECG were taken at rest, during breathing tests and under maximal physical load by ergometry. 88 (23.2%) of them showed arrhythmias, 32 in the same examination different forms of premature beats. All kinds of arrhythmias were seen except atrial flatter, total av-block and paroxysmal tachycardias. Breathing tests provoked most of arrhythmias followed by the recovery after maximal physical load. Follow-up studies and clinical examinations proved that in 86 sportsmen these arrhythmias were not a symptom of heart disease. Only in 2 athletes heart injury could not be excluded. But in nearly 50% extracardial inflammations, like tonsillitis, bronchitis etc., were found. It is discussed that bradycardia and vagotonia of the highly trained sportsmen cause the arrhythmias. This vagotonia is intensified by breathing tests. But arrhythmias found in athletes should cause an examination for other chronical sicknesses. PMID:703672

  19. Arrhythmias in pulmonary arterial hypertension.

    PubMed

    Rajdev, Archana; Garan, Hasan; Biviano, Angelo

    2012-01-01

    Cardiac arrhythmias are important contributors to morbidity and mortality in patients with pulmonary arterial hypertension (PAH). Such patients manifest a substrate resulting from altered autonomics, repolarization abnormalities, and ischemia. Supraventricular arrhythmias such as atrial fibrillation and flutter are associated with worsened outcomes, and maintenance of sinus rhythm is a goal. Sudden death is a relatively common issue, though the contribution of malignant ventricular arrhythmias versus bradyarrhythmias differs from non-PAH patients. Congenital heart disease patients with PAH benefit from catheter ablation of medically refractory arrhythmias. Clinical studies of defibrillator/pacemaker therapy for primary prevention against sudden death in PAH patients are lacking. PMID:23009914

  20. Arrhythmias in Pulmonary Arterial Hypertension

    PubMed Central

    Rajdev, Archana; Garan, Hasan; Biviano, Angelo

    2013-01-01

    Cardiac arrhythmias are important contributors to morbidity and mortality in patients with pulmonary arterial hypertension (PAH). Such patients manifest a substrate resulting from altered autonomics, repolarization abnormalities, and ischemia. Supraventricular arrhythmias such as atrial fibrillation and flutter are associated with worsened outcomes, and maintenance of sinus rhythm is a goal. Sudden death is a relatively common issue, though the contribution of malignant ventricular arrhythmias versus bradyarrhythmias differs from non-PAH patients. Congenital heart disease patients with PAH benefit from catheter ablation of medically refractory arrhythmias. Clinical studies of defibrillator/pacemaker therapy for primary prevention against sudden death in PAH patients are lacking. PMID:23009914

  1. Natural versus anthropogenic subsidence of Venice.

    PubMed

    Tosi, Luigi; Teatini, Pietro; Strozzi, Tazio

    2013-01-01

    We detected land displacements of Venice by Persistent Scatterer Interferometry using ERS and ENVISAT C-band and TerraSAR-X and COSMO-SkyMed X-band acquisitions over the periods 1992-2010 and 2008-2011, respectively. By reason of the larger observation period, the C-band sensors was used to quantify the long-term movements, i.e. the subsidence component primarily ascribed to natural processes. The high resolution X-band satellites reveal a high effectiveness to monitor short-time movements as those induced by human activities. Interpolation of the two datasets and removal of the C-band from the X-band map allows discriminating between the natural and anthropogenic components of the subsidence. A certain variability characterizes the natural subsidence (0.9 ± 0.7 mm/yr), mainly because of the heterogeneous nature and age of the lagoon subsoil. The 2008 displacements show that man interventions are responsible for movements ranging from -10 to 2 mm/yr. These displacements are generally local and distributed along the margins of the city islands. PMID:24067871

  2. Natural versus anthropogenic subsidence of Venice

    PubMed Central

    Tosi, Luigi; Teatini, Pietro; Strozzi, Tazio

    2013-01-01

    We detected land displacements of Venice by Persistent Scatterer Interferometry using ERS and ENVISAT C-band and TerraSAR-X and COSMO-SkyMed X-band acquisitions over the periods 1992–2010 and 2008–2011, respectively. By reason of the larger observation period, the C-band sensors was used to quantify the long-term movements, i.e. the subsidence component primarily ascribed to natural processes. The high resolution X-band satellites reveal a high effectiveness to monitor short-time movements as those induced by human activities. Interpolation of the two datasets and removal of the C-band from the X-band map allows discriminating between the natural and anthropogenic components of the subsidence. A certain variability characterizes the natural subsidence (0.9 ± 0.7 mm/yr), mainly because of the heterogeneous nature and age of the lagoon subsoil. The 2008 displacements show that man interventions are responsible for movements ranging from −10 to 2 mm/yr. These displacements are generally local and distributed along the margins of the city islands. PMID:24067871

  3. [Rational management of arrhythmias].

    PubMed

    González-Hermosillo, J A; Colín, L; Iturralde, P; Romero, L

    1990-01-01

    Despite the development of better diagnostic techniques and new modes of therapy, management of cardiac arrhythmias is still difficult. The lack of standardization in the indications of each technique has increased the risk of overtreatment and unnecessary cost. This paper describes the minimal requirements necessary for the different techniques and the appropriate information that should be collected from each. A well taken clinical history and a 12-lead EKG give very important information for the decision on when and how to treat. PMID:2091549

  4. Arrhythmias in the athlete.

    PubMed

    Bisbal, F; Mont, L

    2012-06-01

    Regular exercise provides substantial health benefits, mostly by reducing cardiovascular risk factors. However, it may also trigger acute cardiac events and cause sudden cardiac death in individuals with a pre-existing condition. In an otherwise healthy population, intense regular exercise may lead to morphological and electrical cardiac adaptations commonly referred as "athlete's heart." Recent data suggest that this may itself produce structural changes of atrial and ventricular myocardium with enlargement and fibrosis, creating the substrate for development of arrhythmias in apparently healthy athletes. The state of the art in this controversial issue is reviewed. PMID:22782729

  5. Mechanisms of cardiac arrhythmias

    PubMed Central

    Tse, Gary

    2015-01-01

    Blood circulation is the result of the beating of the heart, which provides the mechanical force to pump oxygenated blood to, and deoxygenated blood away from, the peripheral tissues. This depends critically on the preceding electrical activation. Disruptions in the orderly pattern of this propagating cardiac excitation wave can lead to arrhythmias. Understanding of the mechanisms underlying their generation and maintenance requires knowledge of the ionic contributions to the cardiac action potential, which is discussed in the first part of this review. A brief outline of the different classification systems for arrhythmogenesis is then provided, followed by a detailed discussion for each mechanism in turn, highlighting recent advances in this area. PMID:27092186

  6. Who Is at Risk for Arrhythmia?

    MedlinePlus

    ... on Twitter. Who Is at Risk for an Arrhythmia? Arrhythmias are very common in older adults. Atrial fibrillation (a common type of arrhythmia that can cause problems) affects millions of people, ...

  7. [New diagnostic tools for arrhythmias].

    PubMed

    Teres, C; Burri, H

    2015-05-27

    Cardiac arrhythmias are common conditions that often manifest themselves intermittently, thus complicating their diagnosis, particularly in the ambulatory setting. Recently, technological advances have facilitated public access to health applications and devices. This article reviews the available technologies and analyses their usefulness for the diagnosis of arrhythmias in the context of everyday clinical practice. PMID:26182638

  8. Using "The Merchant of Venice" in Teaching Monetary Economics.

    ERIC Educational Resources Information Center

    Kish-Goodling, Donna M.

    1999-01-01

    Describes the use of Shakespeare's "The Merchant of Venice" in an undergraduate course in monetary economics, focusing on the usury theme origins of usury laws, scholastic arguments on paying interest for using money, civil usury laws, and modern theories of interest. It is argued that the play provides an interesting vehicle for an…

  9. Using "The Merchant of Venice" in Teaching Monetary Economics.

    ERIC Educational Resources Information Center

    Kish-Goodling, Donna M.

    1998-01-01

    Uses the theme of usury in Shakespeare's "The Merchant of Venice," and the history of Christian and Jewish beliefs concerning the charging of interest on loans to crystallize lending practices throughout history, particularly the medieval period and the transition to modern capitalism. Outlines themes addressed in the unit and assignments. (DSK)

  10. Case Studies in Censorship: Censoring "The Merchant of Venice."

    ERIC Educational Resources Information Center

    Gray, Richard A.

    1991-01-01

    Reviews censorship of "The Merchant of Venice," which has been based on its portrayal of the Jewish character Shylock. Background information is followed by an annotated bibliography which includes 15 citations dealing with Shylock, 22 citations to articles that address the censorship of the play, and 64 works of literature that have been censored…

  11. A Teacher's Guide for "The Merchant of Venice" and "Othello."

    ERIC Educational Resources Information Center

    WGBH-TV, Boston, MA.

    William Shakespeare has influenced most, if not all, Western playwrights. His techniques, themes, characters, and plots are contained in much of what is produced today, from television to Broadway. This teacher's guide provides summaries of the plays "The Merchant of Venice" and "Othello," essays, and corresponding student activities. The…

  12. Tycho Brahe and the Republic of Venice: a failed project

    NASA Astrophysics Data System (ADS)

    Pigatto, Luisa

    In 1592 the Senate of the Republic of Venice issued a decree by which awarded Tycho Brahe `300 coronati' for an astronomical mission to Alexandria in Egypt. The aim was to measure the pole elevation with meridian observations both of Sun and stars. Tycho writes about this project, never carried into execution, in his Astronomiae Instauratae Mechanica of 1598.

  13. Systems Pharmacology of Arrhythmias

    PubMed Central

    Berger, Seth I.; Ma’ayan, Avi; Iyengar, Ravi

    2011-01-01

    Long-QT syndrome (LQTS) is a congenital or drug-induced change in electrical activity of the heart that can lead to fatal arrhythmias. Mutations in 12 genes encoding ion channels and associated proteins are linked with congenital LQTS. With a computational systems biology approach, we found that gene products involved in LQTS formed a distinct functional neighborhood within the human interactome. Other diseases form similarly selective neighborhoods, and comparison of the LQTS neighborhood with other disease-centered neighborhoods suggested a molecular basis for associations between seemingly unrelated diseases that have increased risk of cardiac complications. By combining the LQTS neighborhood with published genome-wide association study data, we identified previously unknown single-nucleotide polymorphisms likely to affect the QT interval. We found that targets of U.S. Food and Drug Administration (FDA)–approved drugs that cause LQTS as an adverse event were enriched in the LQTS neighborhood. With the LQTS neighborhood as a classifier, we predicted drugs likely to have risks for QT effects and we validated these predictions with the FDA’s Adverse Events Reporting System, illustrating how network analysis can enhance the detection of adverse drug effects associated with drugs in clinical use. Thus, the identification of disease-selective neighborhoods within the human interactome can be useful for predicting new gene variants involved in disease, explaining the complexity underlying adverse drug side effects, and predicting adverse event susceptibility for new drugs. PMID:20407125

  14. 76 FR 60113 - Culturally Significant Objects Imported for Exhibition Determinations: “Masters of Venice...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-28

    ... Paintings of Passion and Power from Kunsthistorisches Museum, Vienna'' SUMMARY: Notice is hereby given of... included in the exhibition ``Masters of Venice: Renaissance Paintings of Passion and Power...

  15. Is the 'mose' project to save Venice already obsolete?

    NASA Astrophysics Data System (ADS)

    Pirazzoli, P. A.; Umgiesser, G.

    2003-04-01

    Five meteorological and surge events that occurred during the last decades are analysed, simulating that a relative sea-level rise of 0.5 m (average IPCC prediction for the year 2100 + local subsidence) has taken place and that the "MOSE" gates (the planned mobile protection against flooding of Venice) could have been in operation during the events. In all cases considered, flooding would have occurred in the lowest parts of Venice, lasting for dozen hours, in spite of raising the street level to the +100 cm, or even to the +110 cm levels above the local datum. Problems would start for a sea-level rise of about 25--30 cm, or even of only 10 cm for a repetition of the 1966 event. This is both because the projected gates are not watertight, and rainfall and river discharge contribute to raise the average water level in the lagoon. Therefore, the "MOSE" would be inadequate to protect Venice in the case of the near-future sea-level rise predicted by climatic models for this century. This project might be useful to attenuate surge peaks, but would not prevent gradual floods when the closure durations implied by a sea-level rise will increase. Temporary "diffuse" interventions seem preferable to the "MOSE" gates because they would be safer for the environment and bring back the frequency of flooding to the very acceptable level of about one century ago, thus making possible to gain a few decades. This would give time to verify ongoing evolution and probably to narrow the large uncertainty ranges of present-day estimations. Only with a closer assessment of near-future sea-level rise will it be possible to decide which type of "hard" defence would be eventually necessary to save Venice and its lagoon. Anyway, a stricter control of water pollution should be a priority intervention.

  16. Arrhythmia risk in liver cirrhosis

    PubMed Central

    Mozos, Ioana

    2015-01-01

    Interactions between the functioning of the heart and the liver have been described, with heart diseases affecting the liver, liver diseases affecting the heart, and conditions that simultaneously affect both. The heart is one of the most adversely affected organs in patients with liver cirrhosis. For example, arrhythmias and electrocardiographic changes are observed in patients with liver cirrhosis. The risk for arrhythmia is influenced by factors such as cirrhotic cardiomyopathy, cardiac ion channel remodeling, electrolyte imbalances, impaired autonomic function, hepatorenal syndrome, metabolic abnormalities, advanced age, inflammatory syndrome, stressful events, impaired drug metabolism and comorbidities. Close monitoring of cirrhotic patients is needed for arrhythmias, particularly when QT interval-prolonging drugs are given, or if electrolyte imbalances or hepatorenal syndrome appear. Arrhythmia risk may persist after liver transplantation due to possible QT interval prolongation, persistence of the parasympathetic impairment, post-transplant reperfusion and chronic immunosuppression, as well as consideration of the fact that the transplant itself is a stressful event for the cardiovascular system. The aims of the present article were to provide a review of the most important data regarding the epidemiology, pathophysiology, and biomarkers of arrhythmia risk in patients with liver cirrhosis, to elucidate the association with long-term outcome, and to propose future research directions. PMID:25866603

  17. 1 CFR 5.8 - Form of citation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 1 General Provisions 1 2013-01-01 2012-01-01 true Form of citation. 5.8 Section 5.8 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER THE FEDERAL REGISTER GENERAL § 5.8 Form of citation. Without prejudice to any other form of citation, Federal Register material may be cited by...

  18. 1 CFR 5.8 - Form of citation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 1 General Provisions 1 2014-01-01 2012-01-01 true Form of citation. 5.8 Section 5.8 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER THE FEDERAL REGISTER GENERAL § 5.8 Form of citation. Without prejudice to any other form of citation, Federal Register material may be cited by...

  19. 1 CFR 5.8 - Form of citation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 1 General Provisions 1 2010-01-01 2010-01-01 false Form of citation. 5.8 Section 5.8 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER THE FEDERAL REGISTER GENERAL § 5.8 Form of citation. Without prejudice to any other form of citation, Federal Register material may be cited by...

  20. 1 CFR 5.8 - Form of citation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 1 General Provisions 1 2011-01-01 2011-01-01 false Form of citation. 5.8 Section 5.8 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER THE FEDERAL REGISTER GENERAL § 5.8 Form of citation. Without prejudice to any other form of citation, Federal Register material may be cited by...

  1. 1 CFR 5.8 - Form of citation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 1 General Provisions 1 2012-01-01 2012-01-01 false Form of citation. 5.8 Section 5.8 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER THE FEDERAL REGISTER GENERAL § 5.8 Form of citation. Without prejudice to any other form of citation, Federal Register material may be cited by...

  2. Arrhythmias in the muscular dystrophies.

    PubMed

    Rajdev, Archana; Groh, William J

    2015-06-01

    In patients with muscular dystrophies, cardiac involvement leading to cardiomyopathy and arrhythmias occurs with variable prevalence, mirroring the phenotypic variability seen among and within the various hereditary myopathies. Knowledge of the incidence of arrhythmias and predictors of sudden death in the various hereditary myopathies can help guide screening and appropriate management of these patients, thereby improving survival. The noncardiac manifestations can lead to delayed recognition of symptoms, affect the decision to implant a prophylactic device, and once a decision is made to proceed with device implant, increase peri-procedural respiratory and anesthesia-related complications. PMID:26002394

  3. Sudden Arrhythmia Death Syndromes (SADS) Foundation

    MedlinePlus

    ... all proceeds benefiting the SADS Foundation (Sudden Arrhythmia Death Syndrome). Each year 4,000 young Americans die ... Investigator Awardees 5/19/2016 The Sudden Arrhythmia Death Syndromes (SADS) Foundation announces the winners for the ...

  4. Arrhythmia - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Arrhythmia URL of this page: https://medlineplus.gov/languages/arrhythmia.html Other topics A-Z A B ...

  5. Arrhythmia - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Arrhythmia URL of this page: https://www.nlm.nih.gov/medlineplus/languages/arrhythmia.html Other topics A-Z A B ...

  6. 76 FR 4651 - Venice Gathering System, L.L.C.; Notice of Request Under Blanket Authorization

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-26

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Venice Gathering System, L.L.C.; Notice of Request Under Blanket Authorization January 19, 2010. Take notice that on January 7, 2011, Venice Gathering System, L.L.C....

  7. Arrhythmias in Complex Congenital Heart Disease

    PubMed Central

    Hayward, Robert M.; Tseng, Zian H.

    2014-01-01

    Late after surgical repair of complex congenital heart disease, atrial arrhythmias are a major cause of morbidity, and ventricular arrhythmias and sudden cardiac death are a major cause of mortality. The six cases in this article highlight common challenges in the management of arrhythmias in the adult congenital heart disease population. PMID:25197326

  8. A new hydrogeologic model to predict anthropogenic uplift of Venice

    NASA Astrophysics Data System (ADS)

    Teatini, P.; Castelletto, N.; Ferronato, M.; Gambolati, G.; Tosi, L.

    2011-12-01

    Recent numerical studies based on a simplified lithostratigraphy of the Venice subsurface suggest that the city may be raised by pumping seawater into deep aquifers through 12 wells located on a 10 km diameter circle. Using an updated 3-D reconstruction of the Quaternary deposits, developed very recently from about 1050 km of multichannel seismic profiles and eight exploration wells, along with a more accurate representation of the injection boreholes, novel finite-element predictions are performed. The new model simulates the lithostratigraphy of the lagoon subsurface and allows for a reliable assessment of the water volumes injected into the geologic formations based on the actual bottom hole overpressure that can vary both in space and time. Pumping occurs into two Pleistocene sequences that are originated from the Alps and Apennine sedimentation and terminate just south and north of Venice, respectively, and the shelf portion of a Pliocene sequence that is rather continuous below the central lagoon with arenite layers to depths as much as 1000 m below mean sea level. With a proper tuning of the injection pressure the new hydrogeologic model allows for a prediction of a quite uniform 25-30 cm uplift over 10 years after the inception of injection. The gradient of the vertical displacement ξz does not exceed 5 × 10-5 and 1 × 10-5 in the whole lagoon and Venice, respectively, i.e., well below the most conservative bound recommended for the safety of the structures. If ad hoc calibrated injection overpressures are implemented in each single well, ξz may be reduced to as much as 0.1 × 10-5 throughout the city.

  9. Floating call boys and agile homosexuals: homophobia/Venice/history.

    PubMed

    Champagne, John

    2014-01-01

    Because works of nonfiction are always composed of literary tropes and metaphors, they have to be read critically for the ways in which their truth claims are potentially structured by ideologies and stereotypes. This essay reads passages from Richard Sennett's sociological analysis Flesh and Stone, The Body and the City in Western Civilization and Joseph Brodsky's memoir Watermark in order to demonstrate how these alleged works of nonfiction shore up some dishearteningly familiar literary stereotypes of male homosexuality and participate in a tradition, dating from the 19th century, of linking the city of Venice with homosexuality and death. PMID:24423004

  10. Arrhythmias in the Muscular Dystrophies

    PubMed Central

    Rajdev, Archana; Groh, William J.

    2015-01-01

    Synopsis In patients with muscular dystrophies, cardiac involvement leading to cardiomyopathy and arrhythmias occur with variable prevalence mirroring the phenotypic variability seen among and within the various hereditary myopathies. These patients are at risk for development for bradyarrhythmias and tachyarrhythmias including sudden cardiac death. Knowledge of the incidence of arrhythmias and predictors of sudden death in the various hereditary myopathies can help guide screening and appropriate management of these patients, thereby improving survival. The non-cardiac manifestations can lead to delayed recognition of symptoms (limited mobility and respiratory weakness masking cardiac manifestations), affect decision to implant prophylactic device (quantity vs. quality of life) and once a decision is made to proceed with device implant, increase peri-procedural respiratory and anesthesia-related complications. PMID:26002394

  11. Remote Arrhythmia Monitoring System Developed

    NASA Technical Reports Server (NTRS)

    York, David W.; Mackin, Michael A.; Liszka, Kathy J.; Lichter, Michael J.

    2004-01-01

    Telemedicine is taking a step forward with the efforts of team members from the NASA Glenn Research Center, the MetroHealth campus of Case Western University, and the University of Akron. The Arrhythmia Monitoring System is a completed, working test bed developed at Glenn that collects real-time electrocardiogram (ECG) signals from a mobile or homebound patient, combines these signals with global positioning system (GPS) location data, and transmits them to a remote station for display and monitoring. Approximately 300,000 Americans die every year from sudden heart attacks, which are arrhythmia cases. However, not all patients identified at risk for arrhythmias can be monitored continuously because of technological and economical limitations. Such patients, who are at moderate risk of arrhythmias, would benefit from technology that would permit long-term continuous monitoring of electrical cardiac rhythms outside the hospital environment. Embedded Web Technology developed at Glenn to remotely command and collect data from embedded systems using Web technology is the catalyst for this new telemetry system (ref. 1). In the end-to-end system architecture, ECG signals are collected from a patient using an event recorder and are transmitted to a handheld personal digital assistant (PDA) using Bluetooth, a short-range wireless technology. The PDA concurrently tracks the patient's location via a connection to a GPS receiver. A long distance link is established via a standard Internet connection over a 2.5-generation Global System for Mobile Communications/General Packet Radio Service (GSM/GPRS)1 cellular, wireless infrastructure. Then, the digital signal is transmitted to a call center for monitoring by medical professionals.

  12. Arrhythmias presenting in neonatal lupus.

    PubMed

    Brucato, A; Previtali, E; Ramoni, V; Ghidoni, S

    2010-09-01

    Perfusion of human foetal heart with anti-Ro/SSA antibodies induces transient heart block. Anti-Ro/SSA antibodies may cross-react with T- and L-type calcium channels, and anti-p200 antibodies may cause calcium to accumulate in rat heart cells. These actions may explain a direct electrophysiological effect of these antibodies. Congenital complete heart block is the more severe manifestation of so-called "Neonatal Lupus". In clinical practice, it is important to distinguish in utero complete versus incomplete atrioventricular (AV) block, as complete AV block to date is irreversible, while incomplete AV block has been shown to be potentially reversible after fluorinated steroid therapy. Another issue is the definition of congenital AV block, as cardiologists have considered congenital blocks detected months or years after birth. We propose as congenital blocks detected in utero or within the neonatal period (0-27 days after birth). The possible detection of first degree AV block in utero, with different techniques, might be a promising tool to assess the effects of these antibodies. Other arrhythmias have been described in NL or have been linked to anti-Ro/SSA antibodies: first degree AV block, in utero and after birth, second degree (i.e. incomplete block), sinus bradycardia and QT prolongation, both in infants and in adults, ventricular arrhythmias (in adults). Overall, these arrhythmias have not a clinical relevance, but are important for research purposes. PMID:20696016

  13. Electrical injury causing ventricular arrhythmias.

    PubMed Central

    Jensen, P J; Thomsen, P E; Bagger, J P; Nørgaard, A; Baandrup, U

    1987-01-01

    Dangerous or long lasting ventricular arrhythmias developed in three patients who had sustained an electrical injury in which current passed through the thorax. In all three cases there was a delay of 8-12 hours between the injury and the onset of symptoms. The ventricular arrhythmias were severe and long lasting. In two of the three patients, ventricular tachycardia or ventricular fibrillation or both occurred and in one patient ventricular parasystole developed. No enzymatic evidence of myocardial necrosis was found but the results of an endomyocardial biopsy carried out in two of the three patients showed focal myocardial fibrosis and increased numbers of Na, K-pumps. The two patients with ventricular tachycardia became symptom free after appropriate antiarrhythmic treatment and in the third patient ventricular parasystole disappeared spontaneously within two years. Patients sustaining electrical injury in which current passes through the thorax should be monitored electrocardiographically for at least 24 hours, and patients with unexpected arrhythmias should be questioned about previous electrical injury. Images Fig 2 PMID:3566986

  14. Vibrio Trends in the Ecology of the Venice Lagoon

    PubMed Central

    Rahman, Mohammad Shamsur; Cardazzo, Barbara; Facco, Pierantonio; Bordin, Paola; Mioni, Renzo; Novelli, Enrico; Fasolato, Luca

    2014-01-01

    Vibrio is a very diverse genus that is responsible for different human and animal diseases. The accurate identification of Vibrio at the species level is important to assess the risks related to public health and diseases caused by aquatic organisms. The ecology of Vibrio spp., together with their genetic background, represents an important key for species discrimination and evolution. Thus, analyses of population structure and ecology association are necessary for reliable characterization of bacteria and to investigate whether bacterial species are going through adaptation processes. In this study, a population of Vibrionaceae was isolated from shellfish of the Venice lagoon and analyzed in depth to study its structure and distribution in the environment. A multilocus sequence analysis (MLSA) was developed on the basis of four housekeeping genes. Both molecular and biochemical approaches were used for species characterization, and the results were compared to assess the consistency of the two methods. In addition, strain ecology and the association between genetic information and environment were investigated through statistical models. The phylogenetic and population analyses achieved good species clustering, while biochemical identification was demonstrated to be imprecise. In addition, this study provided a fine-scale overview of the distribution of Vibrio spp. in the Venice lagoon, and the results highlighted a preferential association of the species toward specific ecological variables. These findings support the use of MLSA for taxonomic studies and demonstrate the need to consider environmental information to obtain broader and more accurate bacterial characterization. PMID:24487545

  15. Eukaryotic ribosomes that lack a 5.8S RNA

    NASA Technical Reports Server (NTRS)

    Vossbrinck, C. R.; Woese, C. R.

    1986-01-01

    The 5.8S ribosomal RNA is believed to be a universal eukaryotic characteristic. It has no (size) counterpart among the prokaryotes, although its sequence is homologous with the first 150 or so nucleotides of the prokaryotic large subunit (23S) ribosomal RNA. An exception to this rule is reported here. The microsporidian Vairimorpha necatrix is a eukaryote that has no 5.8S rRNA. As in the prokaryotes, it has a single large subunit rRNA, whose 5-prime region corresponds to the 5.8S rRNA.

  16. Maternal cardiac arrhythmias during pregnancy and lactation

    PubMed Central

    Cordina, Rachael; McGuire, Mark A

    2010-01-01

    Arrhythmias occurring during pregnancy can cause significant symptoms and even death in mother and fetus. The management of these arrhythmias is complicated by the need to avoid harm to the fetus and neonate. It is useful to classify patients with arrhythmias into those with and without structural heart disease. Those with a primary electrical problem, but an otherwise normal heart, often tolerate rapid heart rates without compromise whereas patients with problems such as rheumatic heart disease, congenital heart disease or cardiomyopathy may quickly decompensate during an arrhythmia.

  17. Carbon monoxide and lethal arrhythmias

    SciTech Connect

    Farber, J.P.; Schwartz, P.J.; Vanoli, E.; Stramba-Badiale, M.; De Ferrari, G.M. )

    1990-12-01

    The effect of acute exposure to carbon monoxide on ventricular arrhythmias was studied in a previously described chronically maintained animal model of sudden cardiac death. In 60 percent of dogs with a healed anterior myocardial infarction, the combination of mild exercise and acute myocardial ischemia induces ventricular fibrillation. The events in this model are highly reproducible, thus allowing study by internal control analysis. Dogs that develop ventricular fibrillation during the test of exercise and acute myocardial ischemia are considered at high risk for sudden death and are defined as 'susceptible'; dogs that survive the test without a fatal arrhythmia are considered at low risk for sudden death and are defined as 'resistant.' In the current study, the effects of carboxyhemoglobin levels ranging from 5 to 15 percent were tested in resistant and susceptible dogs. A trend toward higher heart rates was observed at all levels of carboxyhemoglobin, although significant differences were observed only with 15 percent carboxyhemoglobin. This trend was observed at rest and during exercise in both resistant and susceptible dogs. In resistant animals, in which acute myocardial ischemia is typically associated with bradycardia even under the control condition, this reflex response occurred earlier and was augmented after exposure to carbon monoxide. This effect may depend on the increased hypoxic challenge caused by carbon monoxide, and thus on an augmentation of the neural reflex activation or a sensitization of the sinus node to acetylcholine induced by hypoxia. In both resistant and susceptible dogs, carbon monoxide exposure induced a worsening of ventricular arrhythmias in a minority of cases. This worsening was not reproducible in subsequent trials. These data indicate that acute exposure to carbon monoxide is seldom arrhythmogenic in dogs that have survived myocardial infarction. (Abstract Truncated)

  18. Noninvasive mapping of ventricular arrhythmias.

    PubMed

    Shah, Ashok J; Lim, Han S; Yamashita, Seigo; Zellerhoff, Stephan; Berte, Benjamin; Mahida, Saagar; Hooks, Darren; Aljefairi, Nora; Derval, Nicolas; Denis, Arnaud; Sacher, Frédéric; Jais, Pierre; Dubois, Rémi; Hocini, Meleze; Haissaguerre, Michel

    2015-03-01

    Several decades of research has led to the development of a 252-lead electrocardiogram-based three-dimensional imaging modality to refine noninvasive diagnosis and improve the management of heart rhythm disorders. This article reviews the clinical potential of this noninvasive mapping technique in identifying the sources of electrical disorders and guiding the catheter ablation of ventricular arrhythmias (premature ventricular beats and ventricular tachycardia). The article also briefly refers to the noninvasive electrical imaging of the arrhythmogenic ventricular substrate based on the electrophysiologic characteristics of postinfarction ventricular myocardium. PMID:25784026

  19. Arrhythmias

    MedlinePlus

    ... travels through the heart along a set electrical pathway. Different nerve messages signal your heart to beat ... slowed. Electrical signals travel in new or different pathways through the heart. Some common causes of abnormal ...

  20. Arrhythmias

    MedlinePlus

    ... done to look at heart function: Coronary angiography ECG (electrocardiogram) Echocardiogram A special test, called an electrophysiology ... through the middle Heart, front view Atrioventricular block, ECG tracing Normal heart rhythm Bradycardia Ventricular tachycardia Conduction ...

  1. Arrhythmia

    MedlinePlus

    ... chambers. The walls of the heart squeeze together (contract) to push blood through the chambers. The contractions ... heart beats too slowly. Cardiac defibrillation (very brief electric shock) can be used to stop an abnormal ...

  2. Arrhythmias

    MedlinePlus

    ... a heart function test, like an electrocardiogram (ECG/EKG) . continue What's a Normal Heart Rate? Heart rate ... suspected, the doctor will probably recommend an ECG/EKG to measure the heart's electrical activity. There's nothing ...

  3. Macroalgae, nutrient cycles, and pollutants in the lagoon of Venice

    SciTech Connect

    Sfriso, A.; Pavoni, B.; Marcomini, A.; Orio, A.A. )

    1992-12-01

    The Lagoon of Venice is a wide, shallow coastal basin that extends for about 50 km along the northwest coast of the Adriatic Sea. The lagoon has been substantially modified through the actions of man over the last century through the artificial control of the hydraulic dynamics of the lagoon including the construction of channels to facilitate navigation. The lagoon is subjected to considerable pollutant loading through the drainage of land under cultivation, municipal sewage, and industrial effluents. In this paper are reported the results of observations designed to document recent changes in macroalgal species composition, seasonal cycles of primary producers and nutrient levels, and the effects of the macroalgal community on concentrations of organic and inorganic pollutants. The dominant macroalgae in the lagoon was Ulva rigida, and the levels of plant nutrients and pollutants were influenced by the seasonal cycles of the macroalgal community. 44 refs., 11 figs., 2 tabs.

  4. Statistical characterization of spatiotemporal sediment dynamics in the Venice lagoon

    NASA Astrophysics Data System (ADS)

    Carniello, Luca; D'Alpaos, Andrea; Botter, Gianluca; Rinaldo, Andrea

    2016-05-01

    Characterizing the dynamics of suspended sediment is crucial when investigating the long-term evolution of tidal landscapes. Here we apply a widely tested mathematical model which describes the dynamics of cohesive and noncohesive sediments, driven by the combined effect of tidal currents and wind waves, using 1 year long time series of observed water levels and wind data from the Venice lagoon. The spatiotemporal evolution of the computed suspended sediment concentration (SSC) is analyzed on the basis of the "peak over threshold" theory. Our analysis suggests that events characterized by high SSC can be modeled as a marked Poisson process over most of the lagoon. The interarrival time between two consecutive over threshold events, the intensity of peak excesses, and the duration are found to be exponentially distributed random variables over most of tidal flats. Our study suggests that intensity and duration of over threshold events are temporally correlated, while almost no correlation exists between interarrival times and both durations and intensities. The benthic vegetation colonizing the central southern part of the Venice lagoon is found to exert a crucial role on sediment dynamics: vegetation locally decreases the frequency of significant resuspension events by affecting spatiotemporal patterns of SSCs also in adjacent areas. Spatial patterns of the mean interarrival of over threshold SSC events are found to be less heterogeneous than the corresponding patterns of mean interarrivals of over threshold bottom shear stress events because of the role of advection/dispersion processes in mixing suspended sediments within the lagoon. Implications for long-term morphodynamic modeling of tidal environments are discussed.

  5. Free amino acids in atmospheric particulate matter of Venice, Italy

    NASA Astrophysics Data System (ADS)

    Barbaro, Elena; Zangrando, Roberta; Moret, Ivo; Barbante, Carlo; Cescon, Paolo; Gambaro, Andrea

    2011-09-01

    The concentrations of free amino acids were determined in atmospheric particulate matter from the city of Venice (Italy) in order to better understand their origin. The analysis of aerosol samples was carried out via high-performance liquid chromatography coupled to a triple quadrupole tandem mass spectrometric detector (HPLC/ESI-MS/MS). The internal standard method was used and the analytical procedure was validated by evaluating the trueness, the precision, the recovery, the detection and the quantification limits. The particulate matter was collected using quartz fiber filters and extracted in methanol; after filtration the extract was directly analyzed. Forty samples were collected from April to October 2007 and the average concentrations of free amino acids in the aerosol were: alanine 35.6 pmol m -3, aspartic acid 31.1 pmol m -3, glycine 30.1 pmol m -3, glutamic acid 32.5 pmol m -3, isoleucine 2.4 pmol m -3, leucine 2.7 pmol m -3, methionine, cystine and 3-hydroxy-proline below the limit of detection, phenylalanine 2.8 pmol m -3, proline 43.3 pmol m -3, serine 8.6 pmol m -3, threonine 2.8 pmol m -3, tyrosine 1.7 pmolm -3, valine 3.8 pmol m -3, asparagine 70.2 pmol m -3, glutamine 38.0 pmol m -3, 4-hydroxy-proline 2.5 pmol m -3, methionine sulfoxide 1.1 pmol m -3, and methionine sulfone 0.1 pmol m -3. The total average concentration of these free amino acids in aerosol samples of Venice Lagoon was 334 pmol m -3. The temporal evolution and multivariate analysis indicated the photochemical origin of 4-hydroxy-proline and methionine sulfoxide and for other compounds an origin further away from the site of sampling, presumably reflecting transport from terrestrial sources.

  6. Electromechanical wave imaging for arrhythmias

    NASA Astrophysics Data System (ADS)

    Provost, Jean; Thanh-Hieu Nguyen, Vu; Legrand, Diégo; Okrasinski, Stan; Costet, Alexandre; Gambhir, Alok; Garan, Hasan; Konofagou, Elisa E.

    2011-11-01

    Electromechanical wave imaging (EWI) is a novel ultrasound-based imaging modality for mapping of the electromechanical wave (EW), i.e. the transient deformations occurring in immediate response to the electrical activation. The correlation between the EW and the electrical activation has been established in prior studies. However, the methods used previously to map the EW required the reconstruction of images over multiple cardiac cycles, precluding the application of EWI for non-periodic arrhythmias such as fibrillation. In this study, new imaging sequences are developed and applied based on flash- and wide-beam emissions to image the entire heart at very high frame rates (2000 fps) during free breathing in a single heartbeat. The methods are first validated by imaging the heart of an open-chest canine while simultaneously mapping the electrical activation using a 64-electrode basket catheter. Feasibility is then assessed by imaging the atria and ventricles of closed-chest, conscious canines during sinus rhythm and during right-ventricular pacing following atrio-ventricular dissociation, i.e., during a non-periodic rhythm. The EW was validated against electrode measurements in the open-chest case, and followed the expected electrical propagation pattern in the closed-chest setting. These results indicate that EWI can be used for the characterization of non-periodic arrhythmias in conditions similar to the clinical setting, in a single heartbeat, and during free breathing.

  7. Electromechanical Wave Imaging for Arrhythmias

    PubMed Central

    Provost, Jean; Nguyen, Vu Thanh-Hieu; Legrand, Diégo; Okrasinski, Stan; Costet, Alexandre; Gambhir, Alok; Garan, Hasan; Konofagou, Elisa E.

    2015-01-01

    Electromechanical Wave Imaging (EWI) is a novel ultrasound-based imaging modality for the mapping of the electromechanical wave (EW), i.e., the transient deformations occurring in immediate response to the electrical activation. The correlation between the EW and the electrical activation has been established in previous studies. However, the methods used previously to map the EW required the reconstruction of images over multiple cardiac cycle, precluding the application of EWI for non-periodic arrhythmia such as fibrillation. In this study, we develop new imaging sequences based on flash and wide-beam emissions to image the entire heart at very high frame rate (2000 fps) during free breathing in a single heartbeat. The methods are first validated by imaging the heart of an open-chest canine while simultaneously mapping the electrical activation using a 64-electrode basket catheter. Feasibility is then assessed by imaging the atria and ventricles of closed-chest, conscious canines during sinus rhythm and during right-ventricular pacing following atrioventricular dissociation, i.e., a non-periodic rhythm. The EW was validated against electrode measurements in the open-chest case, and followed the expected electrical propagation pattern in the closed-chest setting. These results indicate that EWI can be used for the characterization of non-periodic arrhythmia in conditions close to the clinical setting, in a single heartbeat, and during free-breathing. PMID:22024555

  8. Electromechanical wave imaging for arrhythmias.

    PubMed

    Provost, Jean; Nguyen, Vu Thanh-Hieu; Legrand, Diégo; Okrasinski, Stan; Costet, Alexandre; Gambhir, Alok; Garan, Hasan; Konofagou, Elisa E

    2011-11-21

    Electromechanical wave imaging (EWI) is a novel ultrasound-based imaging modality for mapping of the electromechanical wave (EW), i.e. the transient deformations occurring in immediate response to the electrical activation. The correlation between the EW and the electrical activation has been established in prior studies. However, the methods used previously to map the EW required the reconstruction of images over multiple cardiac cycles, precluding the application of EWI for non-periodic arrhythmias such as fibrillation. In this study, new imaging sequences are developed and applied based on flash- and wide-beam emissions to image the entire heart at very high frame rates (2000 fps) during free breathing in a single heartbeat. The methods are first validated by imaging the heart of an open-chest canine while simultaneously mapping the electrical activation using a 64-electrode basket catheter. Feasibility is then assessed by imaging the atria and ventricles of closed-chest, conscious canines during sinus rhythm and during right-ventricular pacing following atrio-ventricular dissociation, i.e., during a non-periodic rhythm. The EW was validated against electrode measurements in the open-chest case, and followed the expected electrical propagation pattern in the closed-chest setting. These results indicate that EWI can be used for the characterization of non-periodic arrhythmias in conditions similar to the clinical setting, in a single heartbeat, and during free breathing. PMID:22024555

  9. Sinus Node and Atrial Arrhythmias.

    PubMed

    John, Roy M; Kumar, Saurabh

    2016-05-10

    Although sinus node dysfunction (SND) and atrial arrhythmias frequently coexist and interact, the putative mechanism linking the 2 remain unclear. Although SND is accompanied by atrial myocardial structural changes in the right atrium, atrial fibrillation (AF) is a disease of variable interactions between left atrial triggers and substrate most commonly of left atrial origin. Significant advances have been made in our understanding of the genetic and pathophysiologic mechanism underlying the development and progression of SND and AF. Although some patients manifest SND as a result of electric remodeling induced by periods of AF, others develop progressive atrial structural remodeling that gives rise to both conditions together. The treatment strategy will thus vary according to the predominant disease phenotype. Although catheter ablation will benefit patients with predominantly AF and secondary SND, cardiac pacing may be the mainstay of therapy for patients with predominant fibrotic atrial cardiomyopathy. This contemporary review summarizes current knowledge on sinus node pathophysiology with the broader goal of yielding insights into the complex relationship between sinus node disease and atrial arrhythmias. PMID:27166347

  10. [Electrophysiologic study in arrhythmia surgery].

    PubMed

    Nitta, Takashi

    2007-07-01

    The traditional paradigm in surgery for cardiac arrhythmias has been the electrophysiological assessment of the arrhythmia followed by the determination of a specific lesion set for the ablation or a definitive procedure based on the results of the analysis in each patient. The maze procedure was developed as a definitive procedure for atrial fibrillation (AF) and was not guided by electrophysiologic findings in individual patients. The rationale behind the maze procedure is to create a line of conduction block to prevent the propagation of repetitive activations from the pulmonary veins toward the left atrium and to block the reentrant activations occurring on the atrial wall. The cut-and-sew technique is the most reliable method to accomplish conduction block. However, it extends the cardiac arrest and cardiopulmonary times and increases the risk of bleeding. During the past decade, a number of ablation devices have been developed and tested in animals and humans for their ability to create complete conduction block. The use of ablation devices enables less invasive AF surgery. However, the non-transmural or non-contiguous necrosis caused by an incomplete ablation can permit conduction across the ablation line and impair the efficacy of the surgery. Intraoperative verification of conduction block is mandatory to assure the transmurality and contiguity of the lesions created by the ablation devices. PMID:17763669

  11. Atrial Arrhythmia Summit: Post Summit Report

    NASA Technical Reports Server (NTRS)

    Barr, Yael

    2010-01-01

    The Atrial Arrhythmia Summit brought together nationally and internationally recognized experts in cardiology, electrophysiology, exercise physiology, and space medicine in an effort to elucidate the mechanisms, risk factors, and management of atrial arrhythmias in the unique occupational cohort of the U.S. astronaut corps.

  12. Global Issues in the Intermediate Classroom, Grades 5-8.

    ERIC Educational Resources Information Center

    Johnson, Jacquelyn; Benegar, John

    This publication contains teacher developed activities for teaching about global issues in grades 5-8. The self-contained activities are organized into three major parts. Part I, "Global Awareness," introduces students to the concept of global education. Students are made aware of the nature of the world and the part they play in it as inhabitants…

  13. 36 CFR 5.8 - Discrimination in employment practices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Discrimination in employment... INTERIOR COMMERCIAL AND PRIVATE OPERATIONS § 5.8 Discrimination in employment practices. (a) The proprietor... jurisdiction of the United States Department of the Interior. No discrimination in employment practices on...

  14. 36 CFR 5.8 - Discrimination in employment practices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Discrimination in employment... INTERIOR COMMERCIAL AND PRIVATE OPERATIONS § 5.8 Discrimination in employment practices. (a) The proprietor... jurisdiction of the United States Department of the Interior. No discrimination in employment practices on...

  15. 36 CFR 5.8 - Discrimination in employment practices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Discrimination in employment... INTERIOR COMMERCIAL AND PRIVATE OPERATIONS § 5.8 Discrimination in employment practices. (a) The proprietor... jurisdiction of the United States Department of the Interior. No discrimination in employment practices on...

  16. 36 CFR 5.8 - Discrimination in employment practices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Discrimination in employment... INTERIOR COMMERCIAL AND PRIVATE OPERATIONS § 5.8 Discrimination in employment practices. (a) The proprietor... jurisdiction of the United States Department of the Interior. No discrimination in employment practices on...

  17. 36 CFR 5.8 - Discrimination in employment practices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Discrimination in employment... INTERIOR COMMERCIAL AND PRIVATE OPERATIONS § 5.8 Discrimination in employment practices. (a) The proprietor... jurisdiction of the United States Department of the Interior. No discrimination in employment practices on...

  18. Ideas: NCTM Standards-Based Instruction, Grades 5-8.

    ERIC Educational Resources Information Center

    Hynes, Michael C., Ed.

    This document is a collection of activity-based mathematics lessons for grades 5-8 from the "Ideas" department in "Arithmetic Teacher: Mathematics Education through the Middle Grades." Each lesson includes background information, objectives, directions, extensions, and student worksheets. A matrix is included which correlates the titles of the…

  19. 17 CFR 5.8 - Aggregate retail forex assets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 1 2012-04-01 2012-04-01 false Aggregate retail forex assets... FOREIGN CURRENCY TRANSACTIONS § 5.8 Aggregate retail forex assets. (a) Each retail foreign exchange dealer and futures commission merchant offering or engaging in retail forex transactions shall calculate...

  20. 17 CFR 5.8 - Aggregate retail forex assets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 1 2013-04-01 2013-04-01 false Aggregate retail forex assets... FOREIGN CURRENCY TRANSACTIONS § 5.8 Aggregate retail forex assets. (a) Each retail foreign exchange dealer and futures commission merchant offering or engaging in retail forex transactions shall calculate...

  1. 17 CFR 5.8 - Aggregate retail forex assets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 1 2014-04-01 2014-04-01 false Aggregate retail forex assets... FOREIGN CURRENCY TRANSACTIONS § 5.8 Aggregate retail forex assets. (a) Each retail foreign exchange dealer and futures commission merchant offering or engaging in retail forex transactions shall calculate...

  2. Lysophosphatidylcholine (LPC) metabolism and cardiac arrhythmias

    SciTech Connect

    Giffin, D.M.; Man, R.Y.K.; Arthur, G.; Choy, P.C.

    1986-05-01

    The effect of LPC in the production of cardiac arrhythmias in isolated mammalian hearts has been well-documented. Cardiac arrhythmias are initiated by the accumulation of the lysolipid in the cardiac membrane. When isolated rat hearts were perfused in 10 ..mu..M LPC for 10 min, severe arrhythmias were observed in all experiments. In isolated guinea pig hearts that were perfused under identical conditions, the development of severe arrhythmias was never observed, and mild arrhythmias were produced in less than 50% of the hearts used. When the hearts of both species were perfused with (/sup 14/C-palmitate)-LPC, the labellings found in the microsomal fractions (expressed in mg protein) were similar. However, a higher amount of labelled LPC (2-fold) was found in rat heart microsomes, whereas a higher amount of labelled fatty acid was located in the guinea pig heart microsomes. Determination of lysophospholipase activities in these microsomal fractions revealed that the specific activity of the enzyme was much higher in the guinea pig heart than the rat heart. The authors conclude that the differential effect of LPC-induced arrhythmias between the rat and guinea pig heart may be a direct result of the lysophospholipase activities in these hearts. The ability to catabolize LPC more rapidly in the guinea pig heart may decrease the accumulation of LPC in the membrane, and hence, reduce the production of arrhythmias.

  3. POPs in the Lagoon of Venice: budgets and pathways.

    PubMed

    Guerzoni, Stefano; Rossini, Paolo; Sarretta, Alessandro; Raccanelli, Stefano; Ferrari, Giorgio; Molinaroli, Emanuela

    2007-04-01

    Dioxins and furans (PCDD/Fs), polychlorobiphenyls (PCBs) and hexachlorobenzene (HCB) in the ecosystem of the Lagoon of Venice were studied, in order to provide a general picture of conditions in the lagoon in terms of contamination by persistent organic pollutants (POPs). We present here novel data on atmospheric deposition, water, sediment and clam samples collected in the lagoon during the period January 2001-December 2004. Atmospheric deposition was sampled monthly at six sites located both close and far from large industrial and urban sources. Water samples were collected monthly from fifteen stations, and twenty-five samples of sediments and clams (Tapes philippinarum) were collected in four areas where clams are farmed and harvested inside the lagoon. All samples were analysed for PCDD/Fs, PCBs and HCB by HRGC/HRMS in the same laboratory. All samples examined (atmospheric deposition and water) substantially confirmed the spatial pattern reported in previously published data on sediments and atmospheric deposition: the zone surrounding the Porto Marghera petrochemical plant always had the highest levels of POPs (i.e., PCDD/Fs: atmosphere approximately 6 pg of 2,3,7,8-TCDD equivalents (I-TE) m(-2)d(-1); water 0.37 pg I-TEl(-1); sediment: 300 ng kg(-1); clam 2.8 pg I-TE g(-1)), and the minima were found at points on the margins of the lagoon (PCDD/Fs: atmosphere approximately 1 pg I-TEm(-2)d(-1); water 0.05 pg I-TEl(-1); sediment: approximately 5 ng kg(-1); clam approximately 0.2 pg I-TE g(-1)). Intermediate values were often encountered in the historical city centre of Venice and in the central part of the lagoon. To confirm this, new data on correlation between levels of PCDD/F in sediments and clams are reported, both for absolute values and for the PCDD/F "fingerprint". There is always a clear fingerprinting signature (PCDF/PCDD>1) for samples collected near Porto Marghera, and the opposite (PCDF/PCDD<1) in the rest of the lagoon. PMID:17215019

  4. Ship traffic and shoreline erosion in the Lagoon of Venice

    NASA Astrophysics Data System (ADS)

    Scarpa, Gian Marco; Zaggia, Luca; Lorenzetti, Giuliano; Manfè, Giorgia; Parnell, Kevin; Molinaroli, Emanuela; Rapaglia, John; Gionta, Sofia

    2016-04-01

    A study based on the analysis of a historical sequence of aerial photographs and satellite images combined with in situ measurements revealed an unprecedented shoreline regression on the side of a major waterway in the Venice Lagoon, Italy. The study considered long and short-term recession rates caused by ship-induced depression wakes in an area which was reclaimed at the end of the '60 for the expansion of the nearby Porto Marghera Industrial Zone and never used since then. The GIS analysis performed with the available imagery shows an average retreat of about 4 m yr-1 in the period between 1965 and 2015. Field measurements carried out between April 2014 and January 2015 also revealed that the shoreline's regression still proceed with a speed comparable to the long-term average regardless of the distance from the navigation channel and is not constant through time. Periods of high water levels determined by astronomical tide or storm surges, more common in the winter season, are characterized by faster regression rates. The retreat proceeds by collapse of slabs of the reclaimed muddy soil after erosion and removal of the underlying original salt marsh sediments and is a discontinuous process in time and space depending on morphology, intrinsic propertiesand vegetation cover of the artificial deposits. Digitalization of historical maps and new bathymetric surveys made in April 2015 allowed for the reconstruction of two digital terrain models for both past and present situations. The two models have been used to calculate the total volume of sediment lost during the period between 1970 and 2015. The results of this study shows as ship-channel interactions can dominate the morphodynamics of a waterway and its margins and permitted to better understand how this part of the Venice Lagoon reacted to the pressure of human activities in the post-industrial period. Evaluation of the temporal and spatial variation of shoreline position is also crucial to predict future

  5. Improving Literacy Outcomes for Years 5-8 Boys

    ERIC Educational Resources Information Center

    Mercer, Kelly

    2011-01-01

    This paper reports on a small action research project carried out by a Special Education Needs Coordinator (SENCO) in a small rural, full primary school in New Zealand. It focused on improving the literacy outcomes for Years 5-8 boys in the school by way of a boys'-only writing group. Results show that the boys'-only learning group had a positive…

  6. Fragrances as new contaminants in the Venice lagoon.

    PubMed

    Vecchiato, Marco; Cremonese, Simone; Gregoris, Elena; Barbaro, Elena; Gambaro, Andrea; Barbante, Carlo

    2016-10-01

    Fragrance Materials (FMs) are omnipresent components of household and Personal Care Products (PCPs). In spite of their widespread use, little is known about their environmental occurrence. We selected 17 among the longest-lasting and most stable fragrance ingredients that are commercially available, namely: Amberketal, Ambrofix, Amyl Salicylate, Benzyl Salicylate, Bourgeonal, Dupical, Hexyl Salicylate, Isobutavan, Lemonile, Mefranal, Myraldene, Okoumal, Oranger Crystals, Pelargene, Peonile, Tridecene-2-Nitrile, Ultravanil. A new analytical method was developed to quantify FMs in water samples and it was applied to perform the first study about the distribution of these compounds in the surface waters of the city of Venice and its lagoon. Total FMs concentrations range from about 30ngL(-1) to more than 10μgL(-1) in polluted canals during the low tide. Sewage discharges were supposed to be the main sources of the selected FMs in the environment. Salicylates, oestrogenic and allergenic compounds, were in general the most abundant and widespread components. This study reports for the first time the detection of most of the selected FMs in surface waters and represent the first step to understand their environmental fate. PMID:27267717

  7. Cardiac Arrhythmias In Congenital Heart Diseases

    PubMed Central

    Khairy, Paul; Balaji, Seshadri

    2009-01-01

    Arrhythmias figure prominently among the complications encountered in the varied and diverse population of patients with congenital heart disease, and are the leading cause of morbidity and mortality. The incidence generally increases as the patient ages, with multifactorial predisposing features that may include congenitally malformed or displaced conduction systems, altered hemodynamics, mechanical or hypoxic stress, and residual or postoperative sequelae. The safe and effective management of arrhythmias in congenital heart disease requires a thorough appreciation for conduction system variants, arrhythmia mechanisms, underlying anatomy, and associated physiology. We, therefore, begin this review by presenting the scope of the problem, outlining therapeutic options, and summarizing congenital heart disease-related conduction system anomalies associated with disorders of the sinus node and AV conduction system. Arrhythmias encountered in common forms of congenital heart disease are subsequently discussed. In so doing, we touch upon issues related to risk stratification for sudden death, implantable cardiac devices, catheter ablation, and adjuvant surgical therapy. PMID:19898654

  8. Effects of an antiarrhythmic drug A-2545 on canine ventricular arrhythmia models; comparison with mexiletine and flecainide.

    PubMed

    Xue, Y X; Arita, J; Aye, N N; Hashimoto, K

    1998-12-01

    We investigated effects of a new Na+ channel blocking antiarrhythmic drug, A-2545, N-3 (2,2,5,5-tetramethyl-3-pyrroline-3-carboxamido)-propyl-phthalimide-hydro chloride, on various canine ventricular automaticity arrhythmias induced by two-stage coronary ligation, digitalis and adrenaline, and compared them with those of mexiletine. A-2545 showed antiarrhythmic effects, significantly decreasing the arrhythmic ratio of 24-h and 48-h coronary ligation-, digitalis- and adrenaline-induced automaticity arrhythmias. The antiarrhythmic plasma concentrations (IC50) of A-2545, 2 mg kg(-1) 10 min(-1), i.v., for 24-h and 48-h coronary ligation-, digitalis- and adrenaline-induced arrhythmias were 1.8, 1.3, 5.8 and 3.7 microg ml(-1), respectively, and that calculated for oral A-2545 (25 mg kg(-1)) in 24-h coronary ligation-induced arrhythmia was 1.8 microg ml(-1). A-2545 is specifically potent in suppressing coronary ligation-induced arrhythmias, i.e., decreasing the arrhythmic ratio nearly to zero by oral administration, and among the intravenously given experiments A-2545 was effective at lower concentrations than other arrhythmia models; A-2545, 2 mg kg(-1) 10 min(-1), was equipotent to 5 mg kg(-1) 10 min(-1) mexiletine in suppressing 24-h coronary ligation-induced arrhythmia, indicating that A-2545 is more potent than mexiletine. In order to determine whether A-2545 has arrhythmogenic effects, we used programmed electrical stimulation (PES)-induced reentry arrhythmias in dogs with old myocardial infarction and compared effects of A-2545 and flecainide. A-2545, 2 and 5 mg kg(-1) 10 min(-1), significantly suppressed the PES-induced arrhythmias in all six dogs without aggravating them. These arrhythmias were not markedly suppressed by flecainide either with 1 or 3 mg kg(-1) 1O min(-1); moreover even in one out of six dogs aggravation of arrhythmia was noted after 1 mg kg(-1) 10 min(-1). In conclusion, A-2545 suppressed various canine ventricular arrhythmias, and the

  9. Microwave Treatment for Cardiac Arrhythmias

    NASA Technical Reports Server (NTRS)

    Arndt, G. Dickey (Inventor); Carl, James R. (Inventor); Raffoul, George W. (Inventor); Pacifico, Antonio (Inventor)

    1999-01-01

    Method and apparatus are provided for propagating microwave energy into heart tissues to produce a desired temperature profile therein at tissue depths sufficient for thermally ablating arrhythmogenic cardiac tissue to treat ventricular tachycardia and other arrhythmias while preventing excessive heating of surrounding tissues, organs, and blood. A wide bandwidth double-disk antenna is effective for this purpose over a bandwidth of about six gigahertz. A computer simulation provides initial screening capabilities for an antenna such as antenna, frequency, power level, and power application duration. The simulation also allows optimization of techniques for specific patients or conditions. In operation, microwave energy between about 1 Gigahertz and 12 Gigahertz is applied to monopole microwave radiator having a surface wave limiter. A test setup provides physical testing of microwave radiators to determine the temperature profile created in actual heart tissue or ersatz heart tissue. Saline solution pumped over the heart tissue with a peristaltic pump simulates blood flow. Optical temperature sensors disposed at various tissue depths within the heart tissue detect the temperature profile without creating any electromagnetic interference. The method may be used to produce a desired temperature profile in other body tissues reachable by catheter such as tumors and the like.

  10. Arrhythmia in Stem Cell Transplantation

    PubMed Central

    Almeida, Shone O.; Skelton, Rhys J.; Adigopula, Sasikanth; Ardehali, Reza

    2015-01-01

    Synopsis Stem cell regenerative therapies hold promise for treating diseases across the spectrum of medicine. Recent clinical trials have confirmed the safety of stem cell delivery to the heart with promising but variable results. While significant progress has been made in the preclinical stages, the clinical application of cardiac cell therapy is limited by technical challenges, including inability to isolate a pure population of cardiac-specific progenitors capable of robust engraftment and regeneration, lack of appropriate pre-clinical animal models, uncertainty about the best mode of delivery, paucity of adequate imaging modalities, and lack of knowledge about the fate of transplanted cells. The inability of transplanted cells to structurally and functionally integrate into the host myocardium may pose arrhythmogenic risk to patients. This is in part dependent on the type of cell transplanted, where the expression of gap junctions such as connexin-43 is essential not only for electromechanical integration, but has also been found to be protective against electrical instability post-transplant. Additionally, certain methods of cell delivery, such as intramyocardial injection, carry a higher rate of arrhythmias. Other potential contributors to the arrhythmogenicity of cell transplantation include re-entrant pathways due to heterogeneity in conduction velocities between graft and host as well as graft automaticity. In this paper, we discuss the arrhythmogenic potential of cell delivery to the heart. PMID:26002399

  11. Inherited arrhythmias: The cardiac channelopathies.

    PubMed

    Behere, Shashank P; Weindling, Steven N

    2015-01-01

    Ion channels in the myocardial cellular membrane are responsible for allowing the cardiac action potential. Genetic abnormalities in these channels can predispose to life-threatening arrhythmias. We discuss the basic science of the cardiac action potential; outline the different clinical entities, including information regarding overlapping diagnoses, touching upon relevant genetics, new innovations in screening, diagnosis, risk stratification, and management. The special considerations of sudden unexplained death and sudden infant death syndrome are discussed. Scientists and clinicians continue to reconcile the rapidly growing body of knowledge regarding the molecular mechanisms and genetics while continuing to improve our understanding of the various clinical entities and their diagnosis and management in clinical setting. Two separate searches were run on the National Center for Biotechnology Information's website. The first using the term cardiac channelopathies was run on the PubMed database using filters for time (published in past 5 years) and age (birth-18 years), yielding 47 results. The second search using the medical subject headings (MeSH) database with the search terms "Long QT Syndrome" (MeSH) and "Short QT Syndrome" (MeSH) and "Brugada Syndrome" (MeSH) and "Catecholaminergic Polymorphic Ventricular Tachycardia" (MeSH), applying the same filters yielded 467 results. The abstracts of these articles were studied, and the articles were categorized and organized. Articles of relevance were read in full. As and where applicable, relevant references and citations from the primary articles where further explored and read in full. PMID:26556967

  12. Inherited arrhythmias: The cardiac channelopathies

    PubMed Central

    Behere, Shashank P; Weindling, Steven N

    2015-01-01

    Ion channels in the myocardial cellular membrane are responsible for allowing the cardiac action potential. Genetic abnormalities in these channels can predispose to life-threatening arrhythmias. We discuss the basic science of the cardiac action potential; outline the different clinical entities, including information regarding overlapping diagnoses, touching upon relevant genetics, new innovations in screening, diagnosis, risk stratification, and management. The special considerations of sudden unexplained death and sudden infant death syndrome are discussed. Scientists and clinicians continue to reconcile the rapidly growing body of knowledge regarding the molecular mechanisms and genetics while continuing to improve our understanding of the various clinical entities and their diagnosis and management in clinical setting. Two separate searches were run on the National Center for Biotechnology Information's website. The first using the term cardiac channelopathies was run on the PubMed database using filters for time (published in past 5 years) and age (birth-18 years), yielding 47 results. The second search using the medical subject headings (MeSH) database with the search terms “Long QT Syndrome” (MeSH) and “Short QT Syndrome” (MeSH) and “Brugada Syndrome” (MeSH) and “Catecholaminergic Polymorphic Ventricular Tachycardia” (MeSH), applying the same filters yielded 467 results. The abstracts of these articles were studied, and the articles were categorized and organized. Articles of relevance were read in full. As and where applicable, relevant references and citations from the primary articles where further explored and read in full. PMID:26556967

  13. Cardiac arrhythmias during or after epileptic seizures

    PubMed Central

    van der Lende, Marije; Surges, Rainer; Sander, Josemir W; Thijs, Roland D

    2016-01-01

    Seizure-related cardiac arrhythmias are frequently reported and have been implicated as potential pathomechanisms of Sudden Unexpected Death in Epilepsy (SUDEP). We attempted to identify clinical profiles associated with various (post)ictal cardiac arrhythmias. We conducted a systematic search from the first date available to July 2013 on the combination of two terms: ‘cardiac arrhythmias’ and ‘epilepsy’. The databases searched were PubMed, Embase (OVID version), Web of Science and COCHRANE Library. We attempted to identify all case reports and case series. We identified seven distinct patterns of (post)ictal cardiac arrhythmias: ictal asystole (103 cases), postictal asystole (13 cases), ictal bradycardia (25 cases), ictal atrioventricular (AV)-conduction block (11 cases), postictal AV-conduction block (2 cases), (post)ictal atrial flutter/atrial fibrillation (14 cases) and postictal ventricular fibrillation (3 cases). Ictal asystole had a mean prevalence of 0.318% (95% CI 0.316% to 0.320%) in people with refractory epilepsy who underwent video-EEG monitoring. Ictal asystole, bradycardia and AV-conduction block were self-limiting in all but one of the cases and seen during focal dyscognitive seizures. Seizure onset was mostly temporal (91%) without consistent lateralisation. Postictal arrhythmias were mostly found following convulsive seizures and often associated with (near) SUDEP. The contrasting clinical profiles of ictal and postictal arrhythmias suggest different pathomechanisms. Postictal rather than ictal arrhythmias seem of greater importance to the pathophysiology of SUDEP. PMID:26038597

  14. Demons, nature, or God? Witchcraft accusations and the French disease in early modern Venice.

    PubMed

    McGough, Laura J

    2006-01-01

    In early modern Venice, establishing the cause of a disease was critical to determining the appropriate cure: natural remedies for natural illnesses, spiritual solutions for supernatural or demonic ones. One common ailment was the French disease (syphilis), widely distributed throughout Venice's neighborhoods and social hierarchy, and evenly distributed between men and women. The disease was widely regarded as curable by the mid-sixteenth century, and cases that did not respond to natural remedies presented problems of interpretation to physicians and laypeople. Witchcraft was one possible explanation; using expert testimony from physicians, however, the Holy Office ruled out witchcraft as a cause of incurable cases and reinforced perceptions that the disease was of natural origin. Incurable cases were explained as the result of immoral behavior, thereby reinforcing the associated stigma. This article uses archival material from Venice's Inquisition records from 1580 to 1650, as well as mortality data. PMID:16809862

  15. Sediment budget in the Lagoon of Venice, Italy

    NASA Astrophysics Data System (ADS)

    Sarretta, A.; Pillon, S.; Molinaroli, E.; Guerzoni, S.; Fontolan, G.

    2010-05-01

    A comparison of 1927, 1970 and 2002 bathymetric surveys in the Lagoon of Venice was used to reconstruct historical changes in sedimentation. A detailed GIS-based analysis of the charts revealed the timing and pattern of geomorphic changes and allowed calculation of sediment deposition and erosion for the entire lagoon and each of its four sub-basins: Treporti, Lido, Malamocco and Chioggia. Two main developments are discernible from comparative observation of the areal distribution of the main elevation ranges: the diminution in area of the saltmarshes, which decreased by more than 50%, from 68 km 2 in 1927 to 32 km 2 in 2002, and the progressive deepening of the lagoon, with a huge increase in the area of subtidal flats (between -0.75 and -2.00 m depth), from 88 to 206 km 2 during the same period. Generally, the lagoon showed a clear-cut change in the most frequent depths (modal depth) from a value of -0.62 m in 1927 to -0.88 m in 2002. The deepening of the lagoon affected mostly the lagoonal sub-basins south of the town of Venice, where modal depth increased from -0.65 to -1.12 m in Lido, from -0.64 to -1.75 m in Malamocco and from -0.39 to -0.88 m in Chioggia. Large changes in lagoonal morphology were caused by human-induced subsidence, the dredging of navigation channels between 1927 and 1970, and intense natural erosion enhanced by sediment re-suspension due to Manila clam fishing between 1970 and 2002. There was a net loss of about 110 Mm 3 of sediment from the lagoon, most of which (73 Mm 3, ca.70%) was in the earlier period. A significant amount was lost by dredging and direct disposal outside the system, either on land or at sea, and there was a net loss of 39 Mm 3 from the lagoon to the sea through the inlets, at an annual rate of 0.5 Mm 3. Comparison of erosion rates in the two periods revealed an alarming acceleration, from a net sediment loss of 0.3 Mm 3 yr -1 in the period 1927-1970 to 0.8 Mm 3 yr -1 in 1970-2002. Deterioration caused a shift from a

  16. Migration Rate Of Tidal Meanders: Inferences From The Venice Lagoon

    NASA Astrophysics Data System (ADS)

    Finotello, A.; D'Alpaos, A.; Ghinassi, M.; Lanzoni, S.; Marani, M.; Rinaldo, A.

    2015-12-01

    Meandering channels are ubiquitous features of tidal landscapes. However, despite their fundamental role on the eco-morphodynamic evolution of these landscapes, tidal meanders have received less attention when compared to their fluvial counterparts. Improving current understanding of tidal meander migration, a largely-examined topic in fluvial landscapes, is a key step to highlight analogies and differences between tidal and fluvial cases. The migration of about 400 meander bends, belonging to 40 salt-marsh channels in the Northern Venice Lagoon (Italy), from 1968 to nowadays, has been investigated by means of both a classical method in fluvial frameworks and new procedure. Similarities with fluvial meanders occur, although important difference also emerge. Meanders cutting through the San Felice marsh follow the relationship between cartesian length and channel width, typical of meanders developed within different settings. However, meander migration rates proved to be smaller than those characterizing fluvial meanders. Indeed, the analysis of meander migration suggests a mean migration rate of about 0.10 m/year, consistent with the few data available in the literature. As for the fluvial case, the maximum-potential migration rate (i.e. the envelope curve of the relationship between migration rate and bend radius, both divided by channel width) reaches a maximum for radius-over-width ratio included between 2 and 3, regardless of the considered method. Nevertheless, the new-proposed method allows us to provide a more objective and continuous characterization. By using this new procedure, the channel curvature has finally been Fourier-analyzed, confirming the importance of even harmonics along the curvature spectrum. A correlation between migration rates and dominant harmonics seems to drive the evolution of tidal meanders and might represent a key-feature to distinguish them from their fluvial counterparts.

  17. The Taming of the Jew: "The Merchant of Venice" Is No Laughing Matter

    ERIC Educational Resources Information Center

    Beck, Bernard

    2005-01-01

    A new movie version of Shakespeare's classic troubling comedy, "The Merchant of Venice" (Brokaw, Cowan, Navidi, Piette, & Radford, 2004), has appeared, bringing up an ancient issue of the possible bigotry of the greatest writer in the English language. Shakespeare's plays about minority characters in the Venetian Republic have caused more and more…

  18. Understanding "The Merchant of Venice": A Student Casebook to Issues, Sources, and Historical Documents.

    ERIC Educational Resources Information Center

    Halio, Jay L.

    "The Merchant of Venice," even in its own time, was considered William Shakespeare's most controversial play. Now, one of the most popular read and performed works, the play raises even more important issues for today, particularly anti-Semitism and the treatment of Jews. The analysis of the play in this casebook helps students interpret…

  19. Situation Venice: Towards a Performative "Ex-Planation" of a City

    ERIC Educational Resources Information Center

    Whybrow, Nicolas

    2011-01-01

    The article's main concern is to analyse theoretical and artistic factors influencing the attempt by a group of undergraduate students (at the University of Warwick, UK) to produce a "performative mapping" of the city of Venice. In other words, it asks what kind of performance-based strategies might usefully be applied in the process of…

  20. Sedimentation rates and erosion processes in the lagoon of Venice.

    PubMed

    Sfriso, Adriano; Adriano, Sfriso; Facca, Chiara; Chiara, Facca; Marcomini, Antonio; Antonio, Marcomini

    2005-09-01

    Since the early 1990s in the lagoon of Venice, especially in the central basin, the surface sediment underwent high re-suspension and sedimentation changes and water turbidity increased both because of the disappearance of the macroalgal coverage and the harvesting of the Manila clam Tapes philippinarum Adams and Reeve, which had rapidly colonised the bottom free of macrophytes. Clams are harvested with hydraulic and mechanical dredges which remove and re-suspend surface sediments causing the transport and loss of the finest materials. Sediment transport and re-deposition in the lagoon have been monitored with sediment traps placed onto the bottoms near the Malamocco mouth (st. A), the Lido watershed (st. B) and the mainland (sts. C and D). From 1989-1993 to 1998-1999 sedimentation rates increased significantly at st. A (from 41 to 228 kg DW m(-2) year(-1)), st. B (from 65 to 760 kg DW m(-2) year(-1)) and st. C (from 140 to 721 kg DW m(-2) year(-1)), while at st. D sedimentation rates increased only by ca. 20%. In parallel sediment grain-size changed with a loss of the finest fraction especially near the mainland. The erosion or sedimentation status, acquired by utilizing sedimentation devices placed onto the bottoms, showed that sts. B, C, D were affected by sediment losses, while st. A, populated by seagrasses and characterised by seasonal variations which depend on the shoot development, did not show any significant bathymetric change on an annual basis. The highest sediment erosion was recorded at st. D (ca. 3.6 cm year(-1)) whereas a loss of ca. 1.5 and 0.5 cm year(-1) was found at sts. C and B, respectively, which accounted for a mean loss in the central lagoon of ca. 1.2 million tonnes year(-1). Those data agree with the previous indirect estimation of sediment loss which was based on the number of fishing boats operating in the lagoon on an annual basis. PMID:16083960

  1. Noninvasive diagnostic mapping of supraventricular arrhythmias (Wolf-Parkinson-White syndrome and atrial arrhythmias).

    PubMed

    Cakulev, Ivan; Sahadevan, Jayakumar; Waldo, Albert L

    2015-03-01

    The 12-lead electrocardiogram has limited value in precisely identifying the origin of focal or critical component of reentrant arrhythmias during supraventricular arrhythmias, as well as precisely locating accessory atrioventricular conduction pathways. Because of these limitations, efforts have been made to reconstruct epicardial activation sequences from body surface measurements obtained noninvasively. The last decade has registered significant progress in obtaining clinically useful data from the attempts to noninvasively map the epicardial electrical activity. This article summarizes the recent advances made in this area, specifically addressing the clinical outcomes of such efforts relating to atrial arrhythmias and Wolf-Parkinson-White syndrome. PMID:25784024

  2. Arrhythmias: Opening Pandora's Box -- incidental genetic findings.

    PubMed

    Behr, Elijah R; Krahn, Andrew D

    2016-04-01

    A major goal of precision medicine is to improve disease prevention and therapy by using big data provided by genomic technology and electronic health records. In a new study, assessment of a patient population without a history of cardiac disease revealed that genetic variants putatively associated with a risk of sudden death were not linked with arrhythmia phenotypes. PMID:26935036

  3. Cardiac arrhythmias associated with spinal cord injury

    PubMed Central

    Hector, Sven Magnus; Biering-Sørensen, Tor; Krassioukov, Andrei; Biering-Sørensen, Fin

    2013-01-01

    Context/Objectives To review the current literature to reveal the incidence of cardiac arrhythmias and its relation to spinal cord injury (SCI). Methods Data source: MEDLINE database, 304 hits, and 32 articles were found to be relevant. The relevant articles all met the inclusion criteria: (1) contained original data (2) on cardiac arrhythmias (3) in humans with (4) traumatic SCI. Results In the acute phase of SCI (1–14 days after injury) more cranial as well as more severe injuries seemed to increase the incidence of bradycardia. Articles not covering the first 14 days after injury, thus describing the chronic phase of SCI, showed that individuals with SCI did not have a higher incidence of cardiac arrhythmias compared with able-bodied controls. Furthermore, their heart rate did not differ significantly. Penile vibro-stimulation was the procedure investigated most likely to cause bradycardia, which in turn was associated with episodes of autonomic dysreflexia. The incidence of bradycardia was found to be 17–77% for individuals with cervical SCI. For individuals with thoracolumbar SCI, the incidence was 0–13%. Conclusion Bradycardia was commonly seen in the acute stage after SCI as well as during procedures such as penile vibro-stimulation and tracheal suction. These episodes of bradycardia were seen more often in individuals with cervical injuries. Longitudinal studies with continuous electrocardiogram recordings are needed to uncover the true relation between cardiac arrhythmias and SCI. PMID:24090076

  4. Inherited Arrhythmias - Where do we Stand?

    PubMed

    Katritsis, Demosthenes G; Gersh, Bernard J; Camm, A John

    2014-08-01

    This review discusses inherited arrhythmias and conduction disturbances due to genetic disorders. Known channel mutations that are responsible for these conditions are presented, the indications and value of genetic testing are discussed, and a glossary of terms related to the discipline of genetic cardiology has been compiled. PMID:26835071

  5. Cardiac Arrhythmias and Abnormal Electrocardiograms After Acute Stroke.

    PubMed

    Ruthirago, Doungporn; Julayanont, Parunyou; Tantrachoti, Pakpoom; Kim, Jongyeol; Nugent, Kenneth

    2016-01-01

    Cardiac arrhythmias and electrocardiogram (ECG) abnormalities occur frequently but are often underrecognized after strokes. Acute ischemic and hemorrhagic strokes in some particular area of brain can disrupt central autonomic control of the heart, precipitating cardiac arrhythmias, ECG abnormalities, myocardial injury and sometimes sudden death. Identification of high-risk patients after acute stroke is important to arrange appropriate cardiac monitoring and effective management of arrhythmias, and to prevent cardiac morbidity and mortality. More studies are needed to better clarify pathogenesis, localization of areas associated with arrhythmias and practical management of arrhythmias and abnormal ECGs after acute stroke. PMID:26802767

  6. Recommendations and cardiological evaluation of athletes with arrhythmias

    PubMed Central

    Hoogsteen, J.; Bennekers, J.H.; van der Wall, E.E.; van Hemel, N.M.; Wilde, A.A.M.; Crijns, H.J.G.M.; Gorgels, A.P.M.; Smeets, J.L.R.M.; Hauer, R.N.W.; Jordaens, J.L.M.; Schalij, M.J.

    2004-01-01

    Confronted with a competitive or recreational athlete, the physician has to discriminate between benign, paraphysiological and pathological arrhythmias. Benign arrhythmias do not represent a risk for SCD, nor do they induce haemodynamic consequences during athletic activities. These arrhythmias are not markers for heart disease. Paraphysiological arrhythmias are related to athletic performance. Long periods of endurance training induce changes in rhythm, conduction and repolarisation. These changes are fully reversible and disappear when the sport is terminated. Pathological arrhythmias have haemodynamic consequences and express disease, such as sick sinus syndrome, cardiomyopathy or inverse consequences of physical training. Arrhythmias can be classified as bradyarrhythmias and tachyarrhythmias. Conduction disorders can be seen in fast as well as in slow arrhythmias. ImagesFigure 2 PMID:25696329

  7. Transcriptomic resources for environmental risk assessment: a case study in the Venice lagoon.

    PubMed

    Milan, M; Pauletto, M; Boffo, L; Carrer, C; Sorrentino, F; Ferrari, G; Pavan, L; Patarnello, T; Bargelloni, L

    2015-02-01

    The development of new resources to evaluate the environmental status is becoming increasingly important representing a key challenge for ocean and coastal management. Recently, the employment of transcriptomics in aquatic toxicology has led to increasing initiatives proposing to integrate eco-toxicogenomics in the evaluation of marine ecosystem health. However, several technical issues need to be addressed before introducing genomics as a reliable tool in regulatory ecotoxicology. The Venice lagoon constitutes an excellent case, in which the assessment of environmental risks derived from the nearby industrial activities represents a crucial task. In this context, the potential role of genomics to assist environmental monitoring was investigated through the definition of reliable gene expression markers associated to chemical contamination in Manila clams, and their subsequent employment for the classification of Venice lagoon areas. Overall, the present study addresses key issues to evaluate the future outlooks of genomics in the environmental monitoring and risk assessment. PMID:25514060

  8. Cardiac arrhythmias in space. Role of vagotonia.

    PubMed

    Leguay, G; Seigneuric, A

    1981-07-01

    Rhythm disorders observed in space have always been minor but they are not unfrequent. They include: ventricular or supra-ventricular extrasystoles, nodal arrhythmias, auriculo-ventricular conduction disorders. There are several etiopathogenetic hypotheses: a strict selection must permit its elimination of an underlying heart disease; the potassium deficiency is often advanced but its role is not certain; the role of catecholamines is also discussed; the role of hypervagotony is extensively analysed as great clinical and electro-cardiographic evidence speaks for it. It can induce disorders which are more serious than those observed so far, particularly fibrillation or intermittent atrial flutter; weightlessness itself could partly condition the vagotonic state; and the effects of fluid shifts are also discussed from this point of view. The possible therapies for various atrial, nodal, ventricular disorders are reviewed, with greater detail for vagal atrial arrhythmias. PMID:11542963

  9. Non-invasive Mapping of Cardiac Arrhythmias.

    PubMed

    Shah, Ashok; Hocini, Meleze; Haissaguerre, Michel; Jaïs, Pierre

    2015-08-01

    Since more than 100 years, 12-lead electrocardiography (ECG) is the standard-of-care tool, which involves measuring electrical potentials from limited sites on the body surface to diagnose cardiac disorder, its possible mechanism, and the likely site of origin. Several decades of research has led to the development of a 252-lead ECG and computed tomography (CT) scan-based three-dimensional electro-imaging modality to non-invasively map abnormal cardiac rhythms including fibrillation. These maps provide guidance towards ablative therapy and thereby help advance the management of complex heart rhythm disorders. Here, we describe the clinical experience obtained using non-invasive technique in mapping the electrical disorder and guide the catheter ablation of atrial arrhythmias (premature atrial beat, atrial tachycardia, atrial fibrillation), ventricular arrhythmias (premature ventricular beats), and ventricular pre-excitation (Wolff-Parkinson-White syndrome). PMID:26072438

  10. Genetics of inherited primary arrhythmia disorders

    PubMed Central

    Spears, Danna A; Gollob, Michael H

    2015-01-01

    A sudden unexplained death is felt to be due to a primary arrhythmic disorder when no structural heart disease is found on autopsy, and there is no preceding documentation of heart disease. In these cases, death is presumed to be secondary to a lethal and potentially heritable abnormality of cardiac ion channel function. These channelopathies include congenital long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, Brugada syndrome, and short QT syndrome. In certain cases, genetic testing may have an important role in supporting a diagnosis of a primary arrhythmia disorder, and can also provide prognostic information, but by far the greatest strength of genetic testing lies in the screening of family members, who may be at risk. The purpose of this review is to describe the basic genetic and molecular pathophysiology of the primary inherited arrhythmia disorders, and to outline a rational approach to genetic testing, management, and family screening. PMID:26425105

  11. Progressive interatrial block and supraventricular arrhythmias.

    PubMed

    Enriquez, Andres; Conde, Diego; Redfearn, Damian P; Baranchuk, Adrian

    2015-07-01

    Interatrial conduction disorders are frequent in patients with structural heart diseases, including hypertension, coronary disease, and hypertrophic cardiomyopathy, and they are strongly associated with atrial tachyarrhythmias, especially atrial fibrillation and flutter. Conduction delays lead to dispersion of refractory periods and participate in initiating and maintaining reentry circuits, facilitating atrial arrhythmias. In this case, the changing pattern over time is a manifestation of progressive atrial remodeling and conduction delay. The terminal negative component of the P wave in the inferior leads suggests block of the electrical impulse in the Bachman bundle zone, with retrograde activation of the left atria via muscular connections at the coronary sinus. This has been reproduced in experimental models and confirmed by endocardial mapping. Physicians should be aware of the association between advanced interatrial block and development of atrial arrhythmias as its recognition could prompt early and aggressive antiarrhythmic treatment. PMID:25201217

  12. Diagnosis and Treatment of Fetal Arrhythmia

    PubMed Central

    Wacker-Gussmann, Annette; Strasburger, Janette F.; Cuneo, Bettina F.; Wakai, Ronald T.

    2014-01-01

    Detection and careful stratification of fetal heart rate (FHR) is extremely important in all pregnancies. The most lethal cardiac rhythm disturbances occur during apparently normal pregnancies where FHR and rhythmare regular and within normal or low-normal ranges. These hidden depolarization and repolarization abnormalities, associated with genetic ion channelopathies cannot be detected by echocardiography, and may be responsible for up to 10% of unexplained fetal demise, prompting a need for newer and better fetal diagnostic techniques. Other manifest fetal arrhythmias such as premature beats, tachycardia, and bradycardia are commonly recognized. Heart rhythm diagnosis in obstetrical practice is usually made by M-mode and pulsed Doppler fetal echocardiography, but not all fetal cardiac time intervals are captured by echocardiographic methods. This article reviews different types of fetal arrhythmias, their presentation and treatment strategies, and gives an overview of the present and future diagnostic techniques. PMID:24858320

  13. [Managing acute supraventricular arrhythmia in pregnancy].

    PubMed

    Manzo-Silberman, Stéphane

    2015-01-01

    Palpitations: frequent reason for referral to a cardiologist. Arrythmia: rare, mostly benign. Premature extra-beats and sustained tachy-arrhythmias: more frequent or revealed during pregnancy. Hemodynamic changes in expectant women favor an environment conducive to arrhythmogenesis. AF and flutter: very rare unless structural heart disease or hyperthyroidism. Drugs: careful monitoring of the patient and dose adjustments. Cardioversion: only in case of severe symptoms or hemodynamically unstable. PMID:26277779

  14. Catheter Ablation of Arrhythmia During Pregnancy.

    PubMed

    Driver, Kevin; Chisholm, Christian A; Darby, Andrew E; Malhotra, Rohit; Dimarco, John P; Ferguson, John D

    2015-06-01

    Cardiac arrhythmia as a complication of pregnancy can be problematic to maternal health and fetal life and development. Catheter ablation of tachyarrhythmias during pregnancy has been successfully performed in selected patients with limited experience. Techniques to limit maternal and fetal radiation exposure, including intracardiac echo and electroanatomic mapping systems, are particularly important in this setting. Specific accommodations are necessary in the care of the gravid patient during catheter ablation. PMID:25828853

  15. Impact of maritime traffic on polycyclic aromatic hydrocarbons, metals and particulate matter in Venice air.

    PubMed

    Gregoris, Elena; Barbaro, Elena; Morabito, Elisa; Toscano, Giuseppa; Donateo, Antonio; Cesari, Daniela; Contini, Daniele; Gambaro, Andrea

    2016-04-01

    Harbours are important hubs for economic growth in both tourism and commercial activities. They are also an environmental burden being a source of atmospheric pollution often localized near cities and industrial complexes. The aim of this study is to quantify the relative contribution of maritime traffic and harbour activities to atmospheric pollutant concentration in the Venice lagoon. The impact of ship traffic was quantified on various pollutants that are not directly included in the current European legislation for shipping emission reduction: (i) gaseous and particulate PAHs; (ii) metals in PM10; and (iii) PM10 and PM2.5. All contributions were correlated with the tonnage of ships during the sampling periods and results were used to evaluate the impact of the European Directive 2005/33/EC on air quality in Venice comparing measurements taken before and after the application of the Directive (year 2010). The outcomes suggest that legislation on ship traffic, which focused on the issue of the emissions of sulphur oxides, could be an efficient method also to reduce the impact of shipping on primary particulate matter concentration; on the other hand, we did not observe a significant reduction in the contribution of ship traffic and harbour activities to particulate PAHs and metals. Graphical abstract Impact of maritime traffic on polycyclic aromatic hydrocarbons, metals and particulate matter and evaluation of the effect of an European Directive on air quality in Venice. PMID:26681325

  16. Regional and local land subsidence at the Venice coastland by TerraSAR-X PSI

    NASA Astrophysics Data System (ADS)

    Tosi, L.; Strozzi, T.; Da Lio, C.; Teatini, P.

    2015-11-01

    Land subsidence occurred at the Venice coastland over the 2008-2011 period has been investigated by Persistent Scatterer Interferometry (PSI) using a stack of 90 TerraSAR-X stripmap images with a 3 m resolution and a 11-day revisiting time. The regular X-band SAR acquisitions over more than three years coupled with the very-high image resolution has significantly improved the monitoring of ground displacements at regional and local scales, e.g., the entire lagoon, especially the historical palaces, the MoSE large structures under construction at the lagoon inlets to disconnect the lagoon from the Adriatic Sea during high tides, and single small structures scattered within the lagoon environments. Our results show that subsidence is characterized by a certain variability at the regional scale with superimposed important local displacements. The movements range from a gentle uplift to subsidence rates of up to 35 mm yr-1. For instance, settlements of 30-35 mm yr-1 have been detected at the three lagoon inlets in correspondence of the MoSE works, and local sinking bowls up to 10 mm yr-1 connected with the construction of new large buildings or restoration works have been measured in the Venice and Chioggia historical centers. Focusing on the city of Venice, the mean subsidence of 1.1 ± 1.0 mm yr-1 confirms the general stability of the historical center.

  17. Diagnosis of diabetes mellitus at the hospital of Venice in 1863.

    PubMed

    Dall'Olio, G; Dorizzi, R M

    2000-07-01

    In 1674 Thomas Willis reported that the presence of urine 'as sweet as honey' was the pathognomonic sign of diabetes mellitus. In the 19th Century several reactions for the detection of glucose in urine were proposed and glucose measurement became common in the laboratories that were being set up in Europe. A case of diabetes mellitus, diagnosed by Namias, the head of the Women's Section of the Medicine Department of Venice Hospital, was reported in 1863 in the 'Giornale Veneto di Scienze Mediche' which contains clinical and laboratory information. A 34-year-old woman was admitted to the hospital for polydypsia, polyuria, bulimia and fatigue. Urine was weighed for 2 months (2-10 kgday(-1)) and the relative density ranged from 1.045 to 1.038. Glucose was measured in the urine using Moore, Trommer and Fehling reagents. A few days after admission a urine sample showed 7.69 parts/100 parts of urine and a blood sample showed 547 mg of glucose/100 g of serum. The assays were carried out in the Clinical Laboratory of Venice Hospital, founded in 1863, directed by Giovanni Bizio, one of the first chemists who graduated at Padua University. In 1863 chemical analyses were commonly carried out in Venice as in the other parts of Habsburg empire. PMID:10841905

  18. Arrhythmia discrimination using a smart phone.

    PubMed

    Chong, Jo Woon; Esa, Nada; McManus, David D; Chon, Ki H

    2015-05-01

    We hypothesize that our smartphone-based arrhythmia discrimination algorithm with data acquisition approach reliably differentiates between normal sinus rhythm (NSR), atrial fibrillation (AF), premature ventricular contractions (PVCs) and premature atrial contraction (PACs) in a diverse group of patients having these common arrhythmias. We combine root mean square of successive RR differences and Shannon entropy with Poincare plot (or turning point ratio method) and pulse rise and fall times to increase the sensitivity of AF discrimination and add new capabilities of PVC and PAC identification. To investigate the capability of the smartphone-based algorithm for arrhythmia discrimination, 99 subjects, including 88 study participants with AF at baseline and in NSR after electrical cardioversion, as well as seven participants with PACs and four with PVCs were recruited. Using a smartphone, we collected 2-min pulsatile time series from each recruited subject. This clinical application results show that the proposed method detects NSR with specificity of 0.9886, and discriminates PVCs and PACs from AF with sensitivities of 0.9684 and 0.9783, respectively. PMID:25838530

  19. Arrhythmias following spinal anesthesia for cesarean delivery - Is Wenckebach common?

    PubMed Central

    Kalra, Seema; Hayaran, Nitin

    2011-01-01

    Arrhythmias in pregnancy are common and may cause concern for the well-being of both mother and fetus. Generally, no previous history of heart disease is elicited and majority of the arrhythmias are benign. Bradycardia is commonly seen following subarachnoid block for cesarean section. However, the incidence of subsequent heart block is low. This case report highlights the occurrence of perioperative arrhythmias following sympathetic blockade in pregnant patients and their early detection by vigilant monitoring. PMID:22096293

  20. 41 CFR 51-5.8 - Violations by entities of the Government.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Violations by entities of the Government. 51-5.8 Section 51-5.8 Public Contracts and Property Management Other Provisions...-CONTRACTING REQUIREMENTS § 51-5.8 Violations by entities of the Government. Any alleged violations of the...

  1. Basic Cardiac Electrophysiology and Common Drug-induced Arrhythmias.

    PubMed

    Lee, Aimee; Pickham, David

    2016-09-01

    Drugs can be a double-edged sword, providing the benefit of symptom alleviation and disease modification but potentially causing harm from adverse cardiac arrhythmic events. Proarrhythmia is the ability of a drug to cause an arrhythmia, the number one reason for drugs to be withdrawn from the patient. Drug-induced arrhythmias are defined as the production of de novo arrhythmias or aggravation of existing arrhythmias, as a result of previous or concomitant pharmacologic treatment. This review summarizes normal cardiac cell and tissue functioning and provides an overview of drugs that effect cardiac repolarization and the adverse effects of commonly administered antiarrhythmics. PMID:27484663

  2. Classification of cardiac arrhythmias using competitive networks.

    PubMed

    Leite, Cicilia R M; Martin, Daniel L; Sizilio, Glaucia R A; Dos Santos, Keylly E A; de Araujo, Bruno G; Valentim, Ricardo A M; Neto, Adriao D D; de Melo, Jorge D; Guerreiro, Ana M G

    2010-01-01

    Information generated by sensors that collect a patient's vital signals are continuous and unlimited data sequences. Traditionally, this information requires special equipment and programs to monitor them. These programs process and react to the continuous entry of data from different origins. Thus, the purpose of this study is to analyze the data produced by these biomedical devices, in this case the electrocardiogram (ECG). Processing uses a neural classifier, Kohonen competitive neural networks, detecting if the ECG shows any cardiac arrhythmia. In fact, it is possible to classify an ECG signal and thereby detect if it is exhibiting or not any alteration, according to normality. PMID:21096338

  3. Arrhythmia analysis with an expert system.

    PubMed

    Redman, T C; Hahn, A W

    1989-01-01

    We have developed a rule based expert system which was designed to diagnose electrocardiographic arrhythmias in several species. The program, called ECG-X, is written in OPS5 and runs under MS-DOS 2.1 and higher on an IBM-PC or AT type machine. The program uses the paper speed, the species, the temporal relationships between the P waves and the QRS complexes as well as basic information about the P and QRS morphology, and provides the user with a rhythm diagnosis consistent with rules provided by contemporary cardiac electrophysiologic knowledge. PMID:2742969

  4. Drug Resistant Fetal Arrhythmia in Obstetric Cholestasis

    PubMed Central

    Altug, Nahide; Kirbas, Ayse; Daglar, Korkut; Biberoglu, Ebru; Uygur, Dilek; Danisman, Nuri

    2015-01-01

    Obstetric cholestasis (OC) is a pregnancy specific liver disease characterized by increased levels of bile acid (BA) and pruritus. Raised maternal BA levels could be associated with intrauterine death, fetal distress, and preterm labor and also alter the rate and rhythm of cardiomyocyte contraction and may cause fetal arrhythmic events. We report a case of drug resistant fetal supraventricular tachycardia and concomitant OC. Conclusion. If there are maternal OC and concomitant fetal arrhythmia, possibility of the resistance to antiarrhythmic treatment should be kept in mind. PMID:25821617

  5. Difficulties with Ablation for Arrhythmias in Children

    PubMed Central

    Asirvatham, Samuel J

    2008-01-01

    Radiofrequency ablation procedures in children present unique challenges for the electrophysiologist. At times, obtaining vascular access to reach the heart is a problem. If this first step is accomplished, the small size of the child's heart, arrhythmias relatively unique to the pediatric population, and the presence of congenital heart disease add to the complexity. In this manuscript, a review of commonly encountered problems and suggested solutions based on practice are presented. Precise mapping of the arrhythmogenic substrate, techniques to access excluded portions of the atrium from prior surgery, and the basis for electrophysiology maneuvers important in pediatric ablation are highlighted. PMID:18478062

  6. Respiratory sinus arrhythmia in Chagas disease.

    PubMed

    Neves, Victor Ribeiro; Peltola, Mirja; Huikuri, Heikki; Rocha, Manoel Otávio da Costa; Ribeiro, Antonio Luiz

    2014-10-01

    We applied the respiratory sinus arrhythmia (RSA) quantification algorithm to 24-hour ECG recordings of Chagas disease (ChD) patients with (G1, n=148) and without left ventricular dysfunction (LVD) (G2, n=33), and in control subjects (G0, n=28). Both ChD groups displayed a reduced RSA index; G1=299 (144-812); G2=335 (162-667), p=0.011, which was correlated with vagal indexes of heart rate variability analysis. RSA index is a marker of vagal modulation in ChD patients. PMID:25130950

  7. Fetal Arrhythmias Associated with Cardiac Rhabdomyomas

    PubMed Central

    Wacker-Gussmann, Annette; Strasburger, Janette F; Cuneo, Bettina; Wiggins, Delonia; Gotteiner, Nina; Wakai, Ronald T

    2014-01-01

    Background Primary heart tumors in fetuses are rare and mainly represent rhabdomyomas. The tumors have a variable expression and can be associated with arrhythmias, including both wide and narrow QRS tachycardia. Although multiple Doppler techniques exist to assess fetal heart rhythm, it can be difficult to record precise electrophysiological pathologies in fetal life. Objective Investigations defining precise electrophysiological diagnosis were performed using fetal magnetocardiography (fMCG). Methods In addition to routine fetal echocardiography, fMCG was used to investigate electrophysiologic rhythm patterns in a series of 10 fetuses with cardiac rhabdomyomas. Results The mean gestational age of the fetuses was 28.6 weeks (SD ± 4.7 weeks). The multiple rhabdomyomas were mainly located in the right and left ventricles as well as around the AV groove. Arrhythmias or conduction abnormalities were diagnosed in all 10 patients, although only six of them were referred due to that indication. Remarkably, 80% (8/10) had associated Wolff-Parkinson-White pre-excitation. In addition, we found prominent p waves in four fetuses. Conclusion In fetuses with rhabdomyomas, a disease where rhythm pathology is common, precise electrophysiological diagnosis can now be made by fMCG. fMCG is complimentary to echocardiography for rhythm assessment, and can detect conduction abnormalities that are not possible to diagnose prenatally with M-mode or pulsed Doppler ultrasound. Risk factor assessment using fMCG can support pregnancy management and post-natal treatment and follow-up. PMID:24333285

  8. Loperamide Induced Life Threatening Ventricular Arrhythmia

    PubMed Central

    Bodar, Vijaykumar; Singh, Sharanjit; Frumkin, William; Mangla, Aditya; Doshi, Kaushik

    2016-01-01

    Loperamide is over-the-counter antidiarrheal agent acting on peripherally located μ opioid receptors. It is gaining popularity among drug abusers as opioid substitute. We report a case of a 46-year-old male that was presented after cardiac arrest. After ruling out ischemia, cardiomyopathy, pulmonary embolism, central nervous system pathology, sepsis, and other drug toxicity, we found out that patient was using around 100 mg of Loperamide to control his chronic diarrhea presumably because of irritable bowel syndrome for last five years and consumed up to 200 mg of Loperamide daily for last two days before the cardiac arrest. We hypothesize that the patient's QTc prolongation and subsequent cardiac arrest are due to Loperamide toxicity. Patient experienced gradual resolution of tachyarrhythmia and gradual decrease in QTc interval during hospitalization which supports the evidence of causal relationship between Loperamide overdose and potentially fatal arrhythmias. It also provided the clue that patient may have congenital long QT syndrome which was unmasked by Loperamide causing ventricular arrhythmias. This case adds one more pearl in the literature to support that Loperamide overdose related cardiac toxicity does exist and it raises concerns over Loperamide abuse in the community. PMID:27547470

  9. Method for classifying cardiac arrhythmias using photoplethysmography.

    PubMed

    Polania, Luisa F; Mestha, Lalit K; Huang, David T; Couderc, Jean-Philippe

    2015-08-01

    Advances in mobile computing and miniature devices have contributed to the accelerated development of wearable technologies for clinical applications. The new trend of wearable technologies has fostered a growth of interest for sensors that can be easily integrated into wearable devices. In particular, photoplethysmography (PPG) is especially suitable for wearable sensing, as it is low-cost, noninvasive, and does not require wet electrodes like the electrocardiogram. Photoplethysmograph signals contain rich information about the blood pulsating variation which is strongly related to the electrical activities of the heart. Therefore, in this paper we hypothesize that the ambulatory PPG monitoring could be employed for arrhythmia detection and classification. This paper presents a method for classifying ventricular premature contraction (VPC) and ventricular tachycardia (VT) from normal sinus rhythm (NSR) and supraventricular premature contraction (SVPC) recorded in patients going through ablation therapy for arrhythmia. Although occasional VPCs are benign, the increase in the frequency of VPC events may lead to VT, which in turn,could evolve into ventricular fibrillation and sudden cardiac death. Therefore the accurate measurement of VPC frequency and early detection of VT events becomes essential for patients with cardiac disease. PMID:26737799

  10. Caveolae, Ion Channels and Cardiac Arrhythmias

    PubMed Central

    Balijepalli, Ravi C.; Kamp, Timothy J.

    2009-01-01

    Caveolae are specialized membrane microdomains enriched in cholesterol and sphingolipids which are present in multiple cell types including cardiomyocytes. Along with the essential scaffolding protein caveolin-3, a number of different ion channels and transporters have been localized to caveolae in the heart including L-type Ca2+ channels (Cav1.2), Na+ channels (Nav1.5), pacemaker channels (HCN4), Na+/Ca2+ exchnager (NCX1) and others. Closely associated with these channels are specific macromolecular signaling complexes that provide highly localized regulation of the channels. Mutations in the caveolin-3 gene (CAV3) have been linked with the congenital long QT syndrome (LQT9), and mutations in caveolar-localized ion channels may contribute to other inherited arrhythmias. Changes in the caveolar microdomain in acquired heart disease may also lead to dysregulation and dysfunction of ion channels, altering the risk of arrhythmias in conditions such as heart failure. This review highlights the existing evidence identifying and characterizing ion channels localized to caveolae in cardiomyocytes and their role in arrhythmogenesis. PMID:19351512

  11. Loperamide Induced Life Threatening Ventricular Arrhythmia.

    PubMed

    Upadhyay, Ankit; Bodar, Vijaykumar; Malekzadegan, Mohammad; Singh, Sharanjit; Frumkin, William; Mangla, Aditya; Doshi, Kaushik

    2016-01-01

    Loperamide is over-the-counter antidiarrheal agent acting on peripherally located μ opioid receptors. It is gaining popularity among drug abusers as opioid substitute. We report a case of a 46-year-old male that was presented after cardiac arrest. After ruling out ischemia, cardiomyopathy, pulmonary embolism, central nervous system pathology, sepsis, and other drug toxicity, we found out that patient was using around 100 mg of Loperamide to control his chronic diarrhea presumably because of irritable bowel syndrome for last five years and consumed up to 200 mg of Loperamide daily for last two days before the cardiac arrest. We hypothesize that the patient's QTc prolongation and subsequent cardiac arrest are due to Loperamide toxicity. Patient experienced gradual resolution of tachyarrhythmia and gradual decrease in QTc interval during hospitalization which supports the evidence of causal relationship between Loperamide overdose and potentially fatal arrhythmias. It also provided the clue that patient may have congenital long QT syndrome which was unmasked by Loperamide causing ventricular arrhythmias. This case adds one more pearl in the literature to support that Loperamide overdose related cardiac toxicity does exist and it raises concerns over Loperamide abuse in the community. PMID:27547470

  12. Study of water chlorophyl content in the Venice Lagoon through hyperspectral data

    NASA Astrophysics Data System (ADS)

    Garfagnoli, Francesca; Bizzaro, Beatrice; Moretti, Sandro

    2013-04-01

    In the framework of the HICO Project (http://hico.coas.oregonstate.edu/), a number of radiance and reflectance images of the Venice Lagoon were used to evaluate the possibility of performing quick and reliable mapping of water quality parameters. Sponsored by the Office of Naval Research, the Hyperspectral Imager for the Coastal Ocean (HICO™) is the first spaceborne imaging spectrometer specifically designed to sample the coastal areas, with 128 spectral bands, a 90 m spatial resolution, full spectral coverage (380 to 960 nm sampled at 5.7 nm) and a very high signal-to-noise ratio to resolve the complexity of the coastal ocean. Eutrophication is one of the major causes of water quality deterioration. The concentration of chlorophyll-a found in water can be used to trace the abundance of planktonic algae in rivers, lakes or lagoons. The Venice Lagoon, famous worldwide, represents one of the most fragile and vulnerable ecosystems, which is being constantly threatened by factors of stress, both human and natural, such as erosion, presence of urban and agricultural sources of pollution, stress from fishing, pollution produced by the industrial area of Porto Marghera and by the city of Venice itself, downwash of sediments from the hinterland and eutrophication. Traditional methods of water quality estimation are often time consuming and involve periodical sampling and plenty of laboratory analyses. In this study the possibility of using imaging spectroscopy to rapidly obtain raster-based maps of chlorophyll concentration by comparing the results obtained through five different literature bio-optical models, which permit the retrieval of mathematical relations between the water's spectral properties and physicochemical parameters; pH, dissolved oxygen, turbidity and chlorophyll concentration. Evaluation of performances is achieved by comparing the hyperspectral based maps with maps of kriged concentration values, provided by the Magistrato delle Acque di Venezia (http

  13. A Vision of Venice in the next Fin-de-Siècle

    NASA Astrophysics Data System (ADS)

    Tagliapietra, Davide

    2014-05-01

    The IPCC's Fifth Assessment Report projections of sea level rise are larger than in the previous one. In the Adriatic a sea level rise higher than 60 cm is considered possible and rise of one meter cannot be excluded. An end-of-century a scenario in which the mobile barrier at the inlets will not be sufficient to protect the City of Venice from permanent floods is realistic and the closure of the lagoon will become inevitable. The possibility of converting the lagoon of Venice in an enclosed non-tidal basin is discussed. The aim is to protect the City preserving as much as possible the features of a healthy brackish ecosystem able to provide many of the ecosystem services it provides at present. This involves technological challenges, a deeper understanding of the ecological functioning of enclosed coastal basins, and last but not least, a shift in the educational and cultural paradigms. There is the need to endorse a coordinated and large-scale research effort to understand what will be the new hydrology and ecohydrology of the lagoon. The relationship between ecosystem metabolism and hydrology should be approached in the conceptual framework of lagoonal saprobity. Ad hoc research programs with experimental studies and observational monitoring should be implemented to improve our understanding of new ecological scenarios. Among the new opportunities arising from an heavy hydrological management there is the possibility to keep the water at an optimum level for the fruition of the City as it was a few centuries ago. It is likely that the sea level rise would change the entire geographical context. Brackish and freshwater wetlands surrounding the lagoon of Venice, reclaimed during the last century, will be probably ingressed by the sea. An attentive adaptive policy of wetland re-creation could supply both the ecological functions and the ecosystem services lost by the lagoon of Venice. The rapid adoption of a long-term strategy is therefore needed. Strategies should

  14. Atrial Arrhythmias and Their Implications for Space Flight - Introduction

    NASA Technical Reports Server (NTRS)

    Polk, J. D.; Barr, Y. R.; Bauer, P.; Hamilton, D. R.; Kerstman, E.; Tarver, B.

    2010-01-01

    This panel will discuss the implications of atrial arrhythmias in astronauts from a variety of perspectives; including historical data, current practices, and future challenges for exploration class missions. The panelists will present case histories, outline the evolution of current NASA medical standards for atrial arrhythmias, discuss the use of predictive tools, and consider potential challenges for current and future missions.

  15. Perspective: A Dynamics-Based Classification of Ventricular Arrhythmias

    PubMed Central

    Weiss, James N.; Garfinkel, Alan; Karagueuzian, Hrayr S.; Nguyen, Thao P.; Olcese, Riccardo; Chen, Peng-Sheng; Qu, Zhilin

    2015-01-01

    Despite key advances in the clinical management of life-threatening ventricular arrhythmias, culminating with the development of implantable cardioverter-defibrillators and catheter ablation techniques, pharmacologic/biologic therapeutics have lagged behind. The fundamental issue is that biological targets are molecular factors. Diseases, however, represent emergent properties at the scale of the organism that result from dynamic interactions between multiple constantly changing molecular factors. For a pharmacologic/biologic therapy to be effective, it must target the dynamic processes that underlie the disease. Here we propose a classification of ventricular arrhythmias that is based on our current understanding of the dynamics occurring at the subcellular, cellular, tissue and organism scales, which cause arrhythmias by simultaneously generating arrhythmia triggers and exacerbating tissue vulnerability. The goal is to create a framework that systematically links these key dynamic factors together with fixed factors (structural and electrophysiological heterogeneity) synergistically promoting electrical dispersion and increased arrhythmia risk to molecular factors that can serve as biological targets. We classify ventricular arrhythmias into three primary dynamic categories related generally to unstable Ca cycling, reduced repolarization, and excess repolarization, respectively. The clinical syndromes, arrhythmia mechanisms, dynamic factors and what is known about their molecular counterparts are discussed. Based on this framework, we propose a computational-experimental strategy for exploring the links between molecular factors, fixed factors and dynamic factors that underlie life-threatening ventricular arrhythmias. The ultimate objective is to facilitate drug development by creating an in silico platform to evaluate and predict comprehensively how molecular interventions affect not only a single targeted arrhythmia, but all primary arrhythmia dynamics

  16. HERG1 Channel Agonists and Cardiac Arrhythmia

    PubMed Central

    Sanguinetti, Michael

    2014-01-01

    Type 1 human ether-a-go-go-related gene (hERG1) potassium channels are a key determinant of normal repolarization of cardiac action potentials. Loss of function mutations in hERG1 channels cause inherited long QT syndrome and increased risk of cardiac arrhythmia and sudden death. Many common medications that block hERG1 channels as an unintended side effect also increase arrhythmic risk. Routine preclinical screening for hERG1 block led to the discovery of agonists that shorten action potential duration and QT interval. Agonists have the potential to be used as pharmacotherapy for long QT syndrome, but can also be proarrhythmic. Recent studies have elucidated multiple mechanisms of action for these compounds and the structural basis for their binding to the pore domain of the hERG1 channel. PMID:24721650

  17. HERG1 channel agonists and cardiac arrhythmia.

    PubMed

    Sanguinetti, Michael C

    2014-04-01

    Type 1 human ether-a-go-go-related gene (hERG1) potassium channels are a key determinant of normal repolarization of cardiac action potentials. Loss of function mutations in hERG1 channels cause inherited long QT syndrome and increased risk of cardiac arrhythmia and sudden death. Many common medications that block hERG1 channels as an unintended side effect also increase arrhythmic risk. Routine preclinical screening for hERG1 block led to the discovery of agonists that shorten action potential duration and QT interval. Agonists have the potential to be used as pharmacotherapy for long QT syndrome, but can also be proarrhythmic. Recent studies have elucidated multiple mechanisms of action for these compounds and the structural basis for their binding to the pore domain of the hERG1 channel. PMID:24721650

  18. Geochemical characterization of PM10 emitted by glass factories in Murano, Venice (Italy).

    PubMed

    Rampazzo, Giancarlo; Masiol, Mauro; Visin, Flavia; Rampado, Egisto; Pavoni, Bruno

    2008-05-01

    The atmosphere in Venice, like in other European cities, is influenced by complex PM(10) multi-emission sources with a net tendency to exceed the limits fixed by the directive 99/30/EC. This study investigated the composition of an ensemble of similar industrial sources, the Murano Glassmaking Factories (MGFs), and their influence on the Venice air quality, using a modelling approach, statistical analysis and geochemical considerations. Preliminary modelling simulations were conducted to select three sampling sites along the way of preferential transport of pollutants from source between February and April 2003. Subsequently, a sampling campaign was carried out in the same period of simulations. Concentrations of PM(10), eight major elements (Al, Ti, Ca, Mg, Na, K, Fe, Mn), 20 minor and trace elements (Li, V, Cr, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ru, Rh, Cd, Sb, Ba, Ce, Pt, Pb) and four PAHs (BaA, BbF, BkF, BaP) were quantified. The analytical results were statistically processed for exploring the relationships between inorganic elements and organic compounds, and results were interpreted using geochemical considerations. Results show a MGF component of PM(10) characterised by two different fingerprints: the first linked to glass raw material composition and the second mainly related to glass additives. Particularly, Cd, Se, As and Li preserve their ratios in all study area, and are interpreted as principal components of the MGF emissions. Other fingerprints can be traced to urban sources from the Venetian mainland. PMID:18328529

  19. The application of profile imaging for monitoring organic and metal pollution in the Venice lagoon

    SciTech Connect

    Bona, F.; Maffiotti, A.

    1995-12-31

    Since 1993 the technique of Sediment Profile Imaging (SPI) has been applied in monitoring the Venice Lagoon. The purposes of the monitoring were several, ranging from an initial baseline survey of sediment quality, to the control of Ulva rigida proliferation, to sediment quality assessment for dredging and capping activities in restricted areas of the lagoon. Data resulting from each computer image analysis have been summarized in one index which takes into consideration the mutual interactions between the physical and chemical conditions and the benthic community. In this way a spatial and seasonal gradient in the quality Venice Lagoon sediments has been established and the key roles of the organic enrichment and of the ecosystem hydrodynamics have been confirmed. The underwater camera and image analysis have also been an effective screening tool to address further investigations in those areas of particular concern for sediment contamination. On the basis of the SPI indices a selection of stations has been made in order to sample and perform sediment toxicity tests and chemical analyses to assess contamination levels.

  20. Organic micropollutants in wet and dry depositions in the Venice Lagoon.

    PubMed

    Gambaro, Andrea; Radaelli, Marta; Piazza, Rossano; Stortini, Angela Maria; Contini, Daniele; Belosi, Franco; Zangrando, Roberta; Cescon, Paolo

    2009-08-01

    Atmospheric transport is an important route by which pollutants are conveyed from the continents to both coastal and open sea. The role of aerosol deposition in the transport of polycyclic aromatic hydrocarbons (PAHs), polychlorobiphenyls (PCBs) and polybromodiphenyls ethers (PBDEs) to water and soil systems has been evaluated by measuring their concentrations in wet and dry depositions to the Venice Lagoon. The organic micropollutant flux data indicate that they contribute to the total deposition flux in different ways through wet and dry deposition, showing that the prevalent contribution derives from wet deposition. The fluxes calculated for PBDEs, showed the prevalence of 47, 99, 100 and 183 congeners, both in dry and wet fluxes. With regard to PCBs, the flux of summation operatorPCB for wet deposition is in the same order of magnitude of the diffusive flux at the air-water interface. The PAH fluxes obtained in the present study are similar to those obtained in previous studies on the atmospheric bulk deposition to the Venice Lagoon. The ratios between Phe/Ant and Fl/Py indicate that the pollutants sources are pyrolytic, deriving from combustion fuels. PMID:19524283

  1. Wind-induced Resuspension Events in the Venice Lagoon: evidence from the Past and Trends for the Future.

    NASA Astrophysics Data System (ADS)

    D'Alpaos, A.; Carniello, L.; D'Alpaos, L.; Rinaldo, A.

    2015-12-01

    Wind waves promote the erosion and degradation of ubiquitous geomorphic features of tidal landscapes, such as subtidal platforms, tidal flats and salt marshes. Both in the vertical and in the horizontal planes, wind-wave induced erosion is one of the chief processes controlling the morphodynamic evolution of shallow tidal basins. Wind-wave induced bottom shear stresses can promote the disruption of the polymeric microphytobenthic biofilm and lead to the erosion of tidal-flat surfaces and to the increase in suspended sediment concentration which in turn affects the stability of intertidal ecosystems. As an example, the Venice Lagoon has experienced strong erosion processes in the last two centuries, which progressively deepened the lagoonal bottoms, promoted the loss of fine cohesive sediments through the inlets after storms, and lead to the loss of extensive salt-marsh areas. Towards the goal of developing a synthetic theoretical framework to represent wind wave-induced resuspension events and account for their erosional effects on the long-term biomorphodynamic evolution of tidal systems, we employed a full-fledged finite element model accounting for the role of wind waves and tidal currents on the hydrodynamic circulation in shallow basins. Our analyses of the spatial and temporal characteristics of wind-induced erosion events for the actual configuration of the Venice Lagoon and for a few configurations of the last two centuries, allow us to reconstruct erosive trends typical of past Venice Lagoon configurations and to provide predictions on future scenarios for the Venice Lagoon.

  2. Effects of Heterogeneous Diffuse Fibrosis on Arrhythmia Dynamics and Mechanism

    PubMed Central

    Kazbanov, Ivan V.; ten Tusscher, Kirsten H. W. J.; Panfilov, Alexander V.

    2016-01-01

    Myocardial fibrosis is an important risk factor for cardiac arrhythmias. Previous experimental and numerical studies have shown that the texture and spatial distribution of fibrosis may play an important role in arrhythmia onset. Here, we investigate how spatial heterogeneity of fibrosis affects arrhythmia onset using numerical methods. We generate various tissue textures that differ by the mean amount of fibrosis, the degree of heterogeneity and the characteristic size of heterogeneity. We study the onset of arrhythmias using a burst pacing protocol. We confirm that spatial heterogeneity of fibrosis increases the probability of arrhythmia induction. This effect is more pronounced with the increase of both the spatial size and the degree of heterogeneity. The induced arrhythmias have a regular structure with the period being mostly determined by the maximal local fibrosis level. We perform ablations of the induced fibrillatory patterns to classify their type. We show that in fibrotic tissue fibrillation is usually of the mother rotor type but becomes of the multiple wavelet type with increase in tissue size. Overall, we conclude that the most important factor determining the formation and dynamics of arrhythmia in heterogeneous fibrotic tissue is the value of maximal local fibrosis. PMID:26861111

  3. Effects of Heterogeneous Diffuse Fibrosis on Arrhythmia Dynamics and Mechanism.

    PubMed

    Kazbanov, Ivan V; ten Tusscher, Kirsten H W J; Panfilov, Alexander V

    2016-01-01

    Myocardial fibrosis is an important risk factor for cardiac arrhythmias. Previous experimental and numerical studies have shown that the texture and spatial distribution of fibrosis may play an important role in arrhythmia onset. Here, we investigate how spatial heterogeneity of fibrosis affects arrhythmia onset using numerical methods. We generate various tissue textures that differ by the mean amount of fibrosis, the degree of heterogeneity and the characteristic size of heterogeneity. We study the onset of arrhythmias using a burst pacing protocol. We confirm that spatial heterogeneity of fibrosis increases the probability of arrhythmia induction. This effect is more pronounced with the increase of both the spatial size and the degree of heterogeneity. The induced arrhythmias have a regular structure with the period being mostly determined by the maximal local fibrosis level. We perform ablations of the induced fibrillatory patterns to classify their type. We show that in fibrotic tissue fibrillation is usually of the mother rotor type but becomes of the multiple wavelet type with increase in tissue size. Overall, we conclude that the most important factor determining the formation and dynamics of arrhythmia in heterogeneous fibrotic tissue is the value of maximal local fibrosis. PMID:26861111

  4. 43 CFR 3585.5-8 - Decision on plan and participation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Decision on plan and participation. 3585.5-8 Section 3585.5-8 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL LEASING AREAS...

  5. The eSurge-Venice project: altimeter and scatterometer satellite data to improve the storm surge forecasting in the city of Venice

    NASA Astrophysics Data System (ADS)

    Zecchetto, Stefano; De Biasio, Francesco; Umgiesser, Georg; Bajo, Marco; Vignudelli, Stefano; Papa, Alvise; Donlon, Craig; Bellafiore, Debora

    2013-04-01

    On the framework of the Data User Element (DUE) program, the European Space Agency is funding a project to use altimeter Total Water Level Envelope (TWLE) and scatterometer wind data to improve the storm surge forecasting in the Adriatic Sea and in the city of Venice. The project will: a) Select a number of Storm Surge Events occurred in the Venice lagoon in the period 1999-present day b) Provide the available satellite Earth Observation (EO) data related to the Storm Surge Events, mainly satellite winds and altimeter data, as well as all the available in-situ data and model forecasts c) Provide a demonstration Near Real Time service of EO data products and services in support of operational and experimental forecasting and warning services d) Run a number of re-analysis cases, both for historical and contemporary storm surge events, to demonstrate the usefulness of EO data The re-analysis experiments, based on hindcasts performed by the finite element 2-D oceanographic model SHYFEM (https://sites.google.com/site/shyfem/), will 1. use different forcing wind fields (calibrated and not calibrated with satellite wind data) 2. use Storm Surge Model initial conditions determined from altimeter TWLE data. The experience gained working with scatterometer and Numerical Weather Prediction (NWP) winds in the Adriatic Sea tells us that the bias NWP-Scatt wind is negative and spatially and temporally not uniform. In particular, a well established point is that the bias is higher close to coasts then offshore. Therefore, NWP wind speed calibration will be carried out on each single grid point in the Adriatic Sea domain over the period of a Storm Surge Event, taking into account of existing published methods. Point #2 considers two different methodologies to be used in re-analysis tests. One is based on the use of the TWLE values from altimeter data in the Storm Surge Model (SSM), applying data assimilation methodologies and trying to optimize the initial conditions of the

  6. Mechanisms of Ventricular Arrhythmias: From Molecular Fluctuations to Electrical Turbulence

    PubMed Central

    Qu, Zhilin; Weiss, James N.

    2015-01-01

    Ventricular arrhythmias have complex causes and mechanisms. Despite extensive investigation involving many clinical, experimental, and computational studies, effective biological therapeutics are still very limited. In this article, we review our current understanding of the mechanisms of ventricular arrhythmias by summarizing the state of knowledge spanning from the molecular scale to electrical wave behavior at the tissue and organ scales and how the complex nonlinear interactions integrate into the dynamics of arrhythmias in the heart. We discuss the challenges that we face in synthesizing these dynamics to develop safe and effective novel therapeutic approaches. PMID:25340965

  7. Mechanisms of ventricular arrhythmias: from molecular fluctuations to electrical turbulence.

    PubMed

    Qu, Zhilin; Weiss, James N

    2015-01-01

    Ventricular arrhythmias have complex causes and mechanisms. Despite extensive investigation involving many clinical, experimental, and computational studies, effective biological therapeutics are still very limited. In this article, we review our current understanding of the mechanisms of ventricular arrhythmias by summarizing the state of knowledge spanning from the molecular scale to electrical wave behavior at the tissue and organ scales and how the complex nonlinear interactions integrate into the dynamics of arrhythmias in the heart. We discuss the challenges that we face in synthesizing these dynamics to develop safe and effective novel therapeutic approaches. PMID:25340965

  8. An integrated circuit for wireless ambulatory arrhythmia monitoring systems.

    PubMed

    Kim, Hyejung; Yazicioglu, Refet Firat; Torfs, Tom; Merken, Patrick; Van Hoof, Chris; Yoo, Hoi-Jun

    2009-01-01

    An ECG signal processor (ESP) is proposed for the low energy wireless ambulatory arrhythmia monitoring system. The ECG processor mainly performs filtering, compression, classification and encryption. The data compression flow consisting of skeleton and modified Huffman coding is the essential function to reduce the transmission energy consumption and the memory capacity, which are the most energy consuming part. The classification flow performs the arrhythmia analysis to alert the abnormality. The proposed ESP IC is implemented in 0.18-microm CMOS process and integrated into the wireless arrhythmia monitoring sensor platform. By integration of the ESP, the total system energy reduction is evaluated by 95.6%. PMID:19963908

  9. Cardiac arrhythmias during exercise testing in healthy men.

    NASA Technical Reports Server (NTRS)

    Beard, E. F.; Owen, C. A.

    1973-01-01

    Clinically healthy male executives who participate in a long-term physical conditioning program have demonstrated cardiac arrhythmia during and after periodic ergometric testing at submaximal and maximal levels. In 1,385 tests on 248 subjects, it was found that 34% of subjects demonstrated an arrhythmia at some time and 13% of subjects developed arrhythmia on more than one test. Premature systoles of ventricular origin were most common, but premature systoles of atrial origin, premature systoles of junctional origin, paroxysmal atrial tachycardia, atrioventricular block, wandering pacemaker, and pre-excitation were also seen. Careful post-test monitoring and pulse rate regulated training sessions are suggested for such programs.

  10. Global change and relative sea level rise at Venice: what impact in term of flooding

    NASA Astrophysics Data System (ADS)

    Carbognin, Laura; Teatini, Pietro; Tomasin, Alberto; Tosi, Luigi

    2010-11-01

    Relative sea level rise (RSLR) due to climate change and geodynamics represents the main threat for the survival of Venice, emerging today only 90 cm above the Northern Adriatic mean sea level (msl). The 25 cm RSLR occurred over the 20th century, consisting of about 12 cm of land subsidence and 13 cm of sea level rise, has increased the flood frequency by more than seven times with severe damages to the urban heritage. Reasonable forecasts of the RSLR expected to the century end must be investigated to assess the suitability of the Mo.S.E. project planned for the city safeguarding, i.e., the closure of the lagoon inlets by mobile barriers. Here we consider three RSLR scenarios as resulting from the past sea level rise recorded in the Northern Adriatic Sea, the IPCC mid-range A1B scenario, and the expected land subsidence. Available sea level measurements show that more than 5 decades are required to compute a meaningful eustatic trend, due to pseudo-cyclic 7-8 year long fluctuations. The period from 1890 to 2007 is characterized by an average rate of 0.12 ± 0.01 cm/year. We demonstrate that linear regression is the most suitable model to represent the eustatic process over these 117 year. Concerning subsidence, at present Venice is sinking due to natural causes at 0.05 cm/year. The RSLR is expected to range between 17 and 53 cm by 2100, and its repercussions in terms of flooding frequency are associated here to each scenario. In particular, the frequency of tides higher than 110 cm, i.e., the value above which the gates would close the lagoon to the sea, will increase from the nowadays 4 times per year to a range between 20 and 250. These projections provide a large spread of possible conditions concerning the survival of Venice, from a moderate nuisance to an intolerable aggression. Hence, complementary solutions to Mo.S.E. may well be investigated.

  11. On the Lateral Retreat of Salt Marshes: Field Monitoring in the Venice Lagoon (Italy)

    NASA Astrophysics Data System (ADS)

    Solari, L.; Bendoni, M.; Mel, R.; Oumeraci, H.; Francalanci, S.; Lanzoni, S.

    2014-12-01

    Salt marshes are geomorphic structures located in ecotone environments such as lagoon and estuaries, providing lot of ecosystem services to local population. In the last decades they are disappearing due to several factors such as sea level rise, subsidence and edge erosion due to surface waves. The latter is likely the chief mechanism modeling marsh boundaries and leading to the loss of wide marsh areas. In the case of the Venice Lagoon, from the beginning of the last century, the whole salt marsh surface has more than halved and trends indicate that the salt marshes might completely disappear over the next 50 years. Here, we present a field monitoring activity that we are currently carrying out on a retreating salt marsh located in the north part of the Lagoon of Venice (Italy). The marsh is subject to North-East (Bora) wind. Marsh area loss during the last decades has been documented through the comparison of georeferenced aerial photographs showing a retreat rate of the order of 1 m/year. Field measurements started by the end of November 2013 and consist of: salt marsh bank geometry at different cross-sections and wave climate in the lagoon about 30 m in front of the salt marsh. Erosion data are obtained by means of erosion pins located horizontally on the marsh scarp; at higher banks (about 0.9 m), two pins are located along the same vertical direction, for lower banks (about 0.4m), only one pin is employed. Significant wave height has been measured during three storm surges by means of pressure transducers (Pts). The measured wave climate in front of the bank was then put into relationship with the offshore wave climate estimated using wind data (intensity and direction) and bathymetric data. Wind intensity and direction is measured hourly by several measurement stations located in the Lagoon of Venice. In this way, it is possible to extrapolate wave climate hourly at the monitored marsh and calculate the wave power that acted on the bank in a given time

  12. On the Lateral Retreat of Salt Marshes: Field Monitoring in the Venice Lagoon (Italy)

    NASA Astrophysics Data System (ADS)

    Solari, L.

    2015-12-01

    Salt marshes are geomorphic structures located in ecotone environments such as lagoon and estuaries, providing lot of ecosystem services to local population. In the last decades they are disappearing due to several factors such as sea level rise, subsidence and edge erosion due to surface waves. The latter is likely the chief mechanism modeling marsh boundaries and leading to the loss of wide marsh areas. In the case of the Venice Lagoon, from the beginning of the last century, the whole salt marsh surface has more than halved and trends indicate that the salt marshes might completely disappear over the next 50 years. Here, we present a field monitoring activity on a retreating salt marsh located in the north part of the Lagoon of Venice (Italy). The marsh is subject to North-East (Bora) wind. Marsh area loss during the last decades has been documented through the comparison of georeferenced aerial photographs showing a retreat rate of the order of 1 m/year. Field measurements started by the end of November 2013 and consist of: salt marsh bank geometry at different cross-sections and wave climate in the lagoon about 30 m in front of the salt marsh. Erosion data are obtained by means of erosion pins located horizontally on the marsh scarp; at higher banks (about 0.9 m), two pins are located along the same vertical direction, for lower banks (about 0.4 m), only one pin is employed. Significant wave height has been measured during three storm surges by means of pressure transducers. The measured wave climate in front of the bank was then put into relationship with the offshore wave climate estimated using wind data (intensity and direction) and bathymetric data. Wind intensity and direction is measured hourly by several measurement stations located in the Lagoon of Venice. In this way, it is possible to extrapolate wave climate hourly at the monitored marsh and calculate the wave power that acted on the bank in a given time interval. Field survey revealed that the

  13. Cellular and Molecular Mechanisms of Arrhythmia by Oxidative Stress

    PubMed Central

    Sovari, Ali A.

    2016-01-01

    Current therapies for arrhythmia using ion channel blockade, catheter ablation, or an implantable cardioverter defibrillator have limitations, and it is important to search for new antiarrhythmic therapeutic targets. Both atrial fibrillation and heart failure, a condition with increased arrhythmic risk, are associated with excess amount of reactive oxygen species (ROS). There are several possible ways for ROS to induce arrhythmia. ROS can cause focal activity and reentry. ROS alter multiple cardiac ionic currents. ROS promote cardiac fibrosis and impair gap junction function, resulting in reduced myocyte coupling and facilitation of reentry. In order to design effective antioxidant drugs for treatment of arrhythmia, it is essential to explore the molecular mechanisms by which ROS exert these arrhythmic effects. Activation of Ca2+/CaM-dependent kinase II, c-Src tyrosine kinase, protein kinase C, and abnormal splicing of cardiac sodium channels are among the recently discovered molecular mechanisms of ROS-induced arrhythmia. PMID:26981310

  14. An update on risk factors for drug-induced arrhythmias.

    PubMed

    Vlachos, Konstantinos; Georgopoulos, Stamatis; Efremidis, Michael; Sideris, Antonios; Letsas, Konstantinos P

    2016-01-01

    A variety of drugs, either anti-arrhythmics or non-antiarrhythmics, have been associated with drug-induced arrhythmias. Drug-induced arrhythmias are usually observed in the presence of long QT interval or Brugada electrocardiographic pattern. Clinical risk factors, such as female gender, structural heart disease, metabolic and electrolyte abnormalities, bradycardia and conduction disease, increased drug bioavailability, and silent channelopathies act as ''effect amplifiers'' which can make an otherwise relatively safe drug dangerous with regard to risk for polymorphic ventricular tachycardia in the setting of QT interval prolongation. A drug-induced type 1 electrocardiographic pattern of Brugada syndrome is considered highly proarrhythmic. Specific electrocardiographic markers including the corrected QT interval, QRS duration, Tpeak-Tend/QT ratio, and others may predict the risk of arrhythmias in both situations. The present review highlights on the current clinical and electrocardiographic risk factors for prediction of drug-induced arrhythmias. PMID:26460585

  15. Radiofrequency catheter ablation in pediatric patients with supraventricular arrhythmias.

    PubMed

    Rhodes, L A; Lobban, J H; Schmidt, S B

    1995-01-01

    Radiofrequency (RF) ablation of foci leading to abnormal cardiac rhythms is rapidly becoming the procedure of choice in the management of arrhythmias in adults. This report reviews our initial experience with RF ablation in the pediatric population. PMID:8533398

  16. Atrial Arrhythmias in Astronauts. Summary of a NASA Summit

    NASA Technical Reports Server (NTRS)

    Barr, Yael; Watkins, Sharmila; Polk, J. D.

    2011-01-01

    This slide presentation reviews the findings of a panel of heart experts brought together to study if atrial arrhythmias more prevalent in astronauts, and potential risk factors that may predispose astronauts to atrial arrhythmias. The objective of the panel was to solicit expert opinion on screening, diagnosis, and treatment options, identify gaps in knowledge, and propose relevant research initiatives. While Atrial Arrhythmias occur in approximately the same percents in astronauts as in the general population, they seem to occur at younger ages in astronauts. Several reasons for this predisposition were given: gender, hypertension, endurance training, and triggering events. Potential Space Flight-Related Risk factors that may play a role in precipitating lone atrial fibrillation were reviewed. There appears to be no evidence that any variable of the space flight environment increases the likelihood of developing atrial arrhythmias during space flight.

  17. Mechanisms of Arrhythmias and Conduction Disorders in Older Adults

    PubMed Central

    Mirza, Mahek; Strunets, Anton; Shen, Win-Kuang; Jahangir, Arshad

    2012-01-01

    Synopsis Aging is associated with an increased prevalence of cardiac arrhythmias, which contribute to higher morbidity and mortality in the elderly. The frequency of cardiac arrhythmias, particularly atrial fibrillation and ventricular tachyarrhythmia, is projected to increase as the population ages, greatly impacting health care resource utilization. Several clinical factors associated with the risk of arrhythmias have been identified in the population, yet the molecular bases for the increased predisposition to arrhythmogenesis in the elderly are not fully understood. Therefore, only limited therapeutic strategies directed at pathophysiological processes that enhance cardiac vulnerability to arrhythmias are available. This is further compounded by the paucity of outcome studies providing evidence on which optimal management guidelines can be formulated for the very elderly. This review highlights the epidemiology of cardiac dysrhythmias, changes incardiac structure and function associated with aging, and the basis for arrhythmogenesis in the elderly, the understanding of which is critical to formulate preventive strategies. PMID:23101571

  18. Arrhythmia diagnosis and management throughout life in congenital heart disease.

    PubMed

    Clark, Bradley C; Berul, Charles I

    2016-03-01

    Arrhythmias, covering bradycardia and tachycardia, occur in association with congenital heart disease (CHD) and as a consequence of surgical repair. Symptomatic bradycardia can occur due to sinus node dysfunction or atrioventricular block secondary to either unrepaired CHD or surgical repair in the area of the conduction system. Tachyarrhythmias are common in repaired CHD due to scar formation, chamber distension or increased chamber pressure, all potentially leading to abnormal automaticity and heterogeneous conduction properties as a substrate for re-entry. Atrial arrhythmias occur more frequently, but ventricular tachyarrhythmias may be associated with an increased risk of sudden cardiac death, notably in patients with repaired tetralogy of Fallot or aortic stenosis. Defibrillator implantation provides life-saving electrical therapy for hemodynamically unstable arrhythmias. Ablation procedures with 3D electroanatomic mapping technology offer a viable alternative to pharmacologic or device therapy. Advances in electrophysiology have allowed for successful management of arrhythmias in patients with congenital heart disease. PMID:26642231

  19. Cardiac Arrhythmia Management: Why Women Are Different from Men

    MedlinePlus

    ... led to incorrect diagnoses including anxiety neurosis and panic attacks. However, since serotonin reuptake inhibitors can be effective ... Cardiac Arrhythmia Management in Women | Heart Disease Facts | Panic Attack or Heart Attack | Three Women from New Jersey | ...

  20. Arrhythmias in two patients with left ventricular bypass transplants.

    PubMed Central

    Kennelly, B M; Corte, P; Losman, J; Barnard, C N

    1976-01-01

    Two patients who underwent left ventricular bypass transplants are described. Both patients sustained postoperative rhythm disturbances of their own hearts during sinus rhythm of the donor hearts. Illustrative examples of atrial flutter, ventricular flutter, ventricular fibrillation, blocked atrial extrasystoles, and double ventricular parasystole in the recipient hearts are presented. The patients tolerated all these arrhythmias well during uninterrupted sinus rhythm in the donor heart. The problems in interpretation of arrhythmias in the presence of two hearts are discussed. Images PMID:788729

  1. Cardiovascular profiles of scleroderma patients with arrhythmias and conduction disorders.

    PubMed

    Muresan, L; Petcu, A; Pamfil, C; Muresan, C; Rinzis, M; Mada, R O; Gusetu, G N; Pop, D; Zdrenghea, D; Rednic, S

    2016-01-01

    Introduction Arrhythmias and conduction disorders are common among patients with scleroderma. Their early identification is important, since scleroderma patients with arrhythmias have a higher mortality risk compared with scleroderma patients without arrhythmias. The aim of this study was to characterize the cardiovascular profiles of scleroderma patients with different types of arrhythmias and conduction disorders. Methods One hundred and ten consecutive patients with a diagnosis of systemic sclerosis according to the ACR criteria were included in the study. Patients underwent a 12-lead ECG and a 24-hour Holter ECG monitoring for arrhythmias and conduction disorders identification. Blood sample testing, echocardiography, spirometry, chest X-ray and, when considered appropriate, high resolution chest CT were also performed. A subgroup of 21 patients underwent NT-pro BNP level measurements. Patients' clinical and para-clinical characteristics were compared according to the presence or absence of arrhythmias and conduction disorders. Results The prevalence of arrhythmia and conduction disturbances was 60.9%. Patients with such disorders were older (54.4 ± 13.3 vs. 49.7 ± 10.1 years, p=0.05), had a higher prevalence of pulmonary hypertension (p=0.008), valve disease (p < 0.001), especially mitral and tricuspid regurgitation, chamber enlargement on echocardiography (left atrial and right ventricular, p = 0.012 and 0.005, respectively) as well as higher NT-pro BNP levels: 265.5 ± 399.7 vs. 163 ± 264.3 pg/ml, p=0.04. Conclusion Arrhythmias and conduction disorders are common in patients with scleroderma. Patients with such disorders are older, have a higher prevalence of pulmonary hypertension, more severe mitral and tricuspid regurgitation, left atrial and right ventricular dilation on echocardiography. PMID:27115105

  2. Processable, high temperature polymers from 1,4,5,8-tetrahydro-1,4;5,8-diepoxyanthracene and bis-dienes

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B.

    1988-01-01

    1,4,5,8-tetrahydro-1,4;5,8-diepoxyanthracene reacts with various anthracene end-capped polyimide oligomers to form Diels-Alder cycloaddition copolymers. The polymers are soluble in common organic solvents, and have molecular weights of approximately 21,000 to 32,000. These resins exhibit lower weight loss in air than in nitrogen. This is suggested to be due to dehydration (loss of water ranges from 2 to 5 percent) at temperatures of 390 to 400 C to give thermooxidatively stable pentiptycene units along the polymer backbone. Because of their high softening points and good thermooxidative stability, the polymers have potential as processable, matrix resins for high temperature composite applications.

  3. Addition polymers from 1,4,5,8-tetrahydro-1,4;5,8-diepoxyanthracene and Bis-dienes: Processable resins for high temperature application

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B.

    1987-01-01

    1,4,5,8-Tetrahydro-1,4;5,8-diepoxyanthracene reacts with various anthracene endcapped polyimide oligomers to form Diels-Alder cycloaddition copolymers. The polymers are soluble in common organic solvents, and have molecular weights of approximately 21,000 to 32,000. Interestingly, these resins appear to be more stable in air then in nitrogen. This is shown to be due to a unique dehydration (loss of water ranges from 2 to 5 percent) at temperatures of 390 to 400 C to give thermo-oxidatively stable pentiptycene units along the polymer backbone. Because of their high softening points and good thermo-oxidative stability, the polymers have potential as processible, matrix resins for high temperature composite applications.

  4. Ethanol for the treatment of cardiac arrhythmias

    PubMed Central

    Schurmann, Paul; Peñalver, Jorge; Valderrábano, Miguel

    2015-01-01

    Introduction Ethanol infusion was an early mode of ablative treatment for cardiac arrhythmias. Its initial descriptions involved coronary intra-arterial delivery, targeting arrhythmogenic substrates in drug-refractory ventricular tachycardia or the atrioventricular node. Largely superseded by radiofrequency ablation (RFA) and other contact-based technologies as a routine ablation strategy, intracoronary arterial ethanol infusion remains as an alternative option in the treatment of ventricular tachycardia when conventional ablation fails. Arrhythmic foci that are deep-seated in the myocardium may not be amenable to catheter ablation from either the endocardium or the epicardium by RFA, but they can be targeted by an ethanol infusion. Recent findings Recently, we have explored ethanol injection through cardiac venous systems, in order to avoid the risks of complications and limitations of coronary arterial instrumentation. Vein of Marshall ethanol infusion is being studied as an adjunctive procedure in ablation of atrial fibrillation, and coronary venous ethanol infusion for ventricular tachycardia. Conclusion Ethanol ablation remains useful as a bail-out technique for refractory cases to RFA, or as an adjunctive therapy that may improve the efficacy of catheter ablation procedures. PMID:26049378

  5. [Treatment of arrhythmia in atrial fibrillation].

    PubMed

    Daubert, Jean-Claude; Pavin, Dominique

    2013-02-01

    The initial therapy after onset of atrial fibrillation (AF) should always include adequate antithrombotic treatment and control of the ventricular rate. Depending on the patient's course, this strategy may prove insufficient and may then be supplemented by rhythm control using drugs or interventions. Clinical frustration came by clinical trials that have demonstrated that the strategy of maintaining sinus rhythm has no demonstrable value when compared with the "laissez-faire" approach of leaving AF to a permanent form and controlling ventricular rate. These disappointing findings can be considered as paradoxical when considering the severe complications associated with AF in epidemiological studies. New anti-arrhythmic approaches might offer added value but this is still a matter of debate. Non-pharmacological interventions to prevent AF recurrences or to limit its expression have been substantially developed in the past decade. Ablation techniques, usually done percutaneously using a catheter, have proved successful n the treatment of AF, particularly by reducing the symptomatic burden associated with the arrhythmia, to such an extent that a 'cure' may be achieved in some patients with paroxysmal AF. PMID:23513784

  6. Update on management of cardiac arrhythmias in acute coronary syndromes.

    PubMed

    Willich, T; Goette, A

    2015-04-01

    This review summarizes different types of arrhythmias in patients with acute coronary syndromes and provides an overview of the available therapeutic options for acute care and management of critical arrhythmias. The different therapeutic options are depending on the origin and type of arrhythmia. The main common dominant mechanisms are intramural re-entry in ischemia and triggered activity in reperfusion. The different forms of arrhythmia were explained in detail. Atrial arrhythmias are mainly atrial fibrillation; other forms are rare and usually self-limited. As therapeutic options antiarrhythmic drug therapy with beta-blockers or amiodarone and direct current cardioversion are suitable. Ventricular arrhythmias can be divided in premature ventricular complexes, accelerated idioventricular rhythm, non-sustained ventricular tachycardia, sustained ventricular tachycardia (VT), ventricular fibrillation (VF) and electrical storm. As therapeutic options antiarrhythmic drug therapy, implantable cardioverter defibrillator therapy (ICD), radiofrequency catheter ablation (RFA) and stellate ganglion blockade are available. The treatment with antiarrhythmic drug is rather cautious recommended, with the exception of beta-blockers. An additional drug therapy with ranolazine may be considered. The advantage of ICD therapy for long-term primary or secondary prophylactic therapy has been well documented. ICD therapy is associated with significant reduction in mortality compared with antiarrhythmic drug therapy (mainly amiodarone), with the exception of beta-blockers. RFA and stellate ganglion blockade are rather intended as therapeutically options for incessant VT/VF or electrical storm. PMID:25612305

  7. Masterplan to safeguard Venice and to restore the lagoon and conterminous areas

    NASA Astrophysics Data System (ADS)

    Bini, Claudio; Gallo, Alba; Nadimi-Goki, Mandana; Wahsha, Mohammad

    2015-04-01

    Venice and its lagoon constitute a complex system, well known all over the world for the peculiarity of the town and for the fragility of the lagoon ecosystem with its delicate equilibrium. The whole system has been, and is currently, affected by human activities (industry, agriculture, settlements, tourism) that impact severely the ecosystem. Discharge from the agricultural drainage basin affects particularly the area North of the city of Venice; the central and southern areas, instead, receive important pollutant inputs from the industrial zone of Porto Marghera since the early'50s. Additional sources of pollution are domestic sewage and waste disposal from the urban area, that is visited by more than 10M people every year. As a consequence of the increasing land contamination, significant amounts of contaminants (both organic and inorganic) are accumulated in soils of the borderline, in water and in lagoon sediments, which constitute a potential source of secondary pollution. Results of surveys carried out in recent years in the whole area show that contaminants concentration increased from the beginning of the industrial activities until the '90s, when Porto Marghera declined. Most of contaminants have concentrations above the background levels. The highest metal levels were found in an area between Porto Marghera and the city of Venice, where both industrial and urban sewage are discharged, provoking environmental and human health hazard. In order to safeguard the city of Venice, and to restore its lagoon and conterminous areas, a Master Plan of intervention has been developed since the early 2000s. The land currently interested by environmental analysis and/or restoration covers approximately 1350ha; 78% of these (1100ha) proved variously contaminated, with 85% of sites overcoming the National Reference Values. Contamination, besides being diffused, is quite complex, involving the co-existence of several contaminant families (PAH, PCB, dioxin, heavy metals

  8. Dynamics of ship-induced solitary wave troughs in Venice Lagoon

    NASA Astrophysics Data System (ADS)

    Parnell, Kevin E.; Soomere, Tarmo; Zaggia, Luca; Rodin, Artem

    2015-04-01

    Based on experiments in the industrial channel of the Venice Lagoon, we demonstrate that ship-induced depressions (Bernoulli wakes) may propagate as long-living strongly nonlinear Riemann waves of depression into shallow water adjacent to navigation channels. Ships of moderate size (blocking coefficient 0.07-0.14) and sailing at low depth Froude numbers (0.37-0.5) produce depressions with a depth up to 2.5 m. The waves of depression decrease in height away from the channel before increasing in very shallow water. As the waves propagate into and through shallow water surrounding the navigation channel, they become strongly asymmetric with the rear of the depression wave becoming extremely steep, similar to a bore, and may be associated with very high water velocities.

  9. Harmful Algae Records in Venice Lagoon and in Po River Delta (Northern Adriatic Sea, Italy)

    PubMed Central

    Bilaničovà, Dagmar; Marcomini, Antonio

    2014-01-01

    A detailed review of harmful algal blooms (HAB) in northern Adriatic Sea lagoons (Po River Delta and Venice lagoon) is presented to provide “updated reference conditions” for future research and monitoring activities. In the study areas, the high mollusc production requires the necessity to identify better methods able to prevent risks for human health and socioeconomical interests. So, an integrated approach for the identification and quantification of algal toxins is presented by combining microscopy techniques with Liquid Chromatography coupled with High Resolution Time of Flight Mass Spectrometry (HPLC-HR-TOF-MS). The method efficiency was first tested on some samples from the mentioned coastal areas, where Dinophysis spp. occurred during summer in the sites directly affected by seawaters. Although cell abundance was always <200 cells/L, the presence of Pectenotoxin-2 (PTX2), detected by HPLC-HR-TOF-MS, indicated the potential release of detectable amounts of toxins even at low cell abundance. PMID:24683360

  10. Surface water-groundwater exchange in transitional coastal environments by airborne electromagnetics: The Venice Lagoon example

    NASA Astrophysics Data System (ADS)

    Viezzoli, A.; Tosi, L.; Teatini, P.; Silvestri, S.

    2010-01-01

    A comprehensive investigation of the mixing between salt/fresh surficial water and groundwater in transitional environments is an issue of paramount importance considering the ecological, cultural, and socio-economic relevance of coastal zones. Acquiring information, which can improve the process understanding, is often logistically challenging, and generally expensive and slow in these areas. Here we investigate the capability of airborne electromagnetics (AEM) at the margin of the Venice Lagoon, Italy. The quasi-3D interpretation of the AEM outcome by the spatially constrained inversion (SCI) methodology allows us to accurately distinguish several hydrogeological features down to a depth of about 200 m. For example, the extent of the saltwater intrusion in coastal aquifers and the transition between the upper salt saturated and the underlying fresher sediments below the lagoon bottom are detected. The research highlights the AEM capability to improve the hydrogeological characterization of subsurface processes in worldwide lagoons, wetlands, deltas.

  11. Interannual heavy element and nutrient concentration trends in the top sediments of Venice Lagoon (Italy).

    PubMed

    Masiol, Mauro; Facca, Chiara; Visin, Flavia; Sfriso, Adriano; Pavoni, Bruno

    2014-12-15

    The elemental composition of surficial sediments of Venice Lagoon (Italy) in 1987, 1993, 1998 and 2003 were investigated. Zn and Cr concentrations resulted in higher than background levels, but only Cd and Hg were higher than legal quality standards (Italian Decree 2010/260 and Water Framework Directive 2000/60/EC). Contaminants with similar spatial distribution are sorted into three groups by means of correlation analysis: (i) As, Co, Cd, Cu, Fe, Pb, Zn; (ii) Ni, Cr; (iii) Hg. Interannual concentrations are compared by applying a factor analysis to the matrix of differences between subsequent samplings. A general decrease of heavy metal levels is observed from 1987 to 1993, whereas particularly high concentrations of Ni and Cr are recorded in 1998 as a consequence of intense clam fishing, subsequently mitigated by better prevention of illegal harvesting. Due to the major role played by anthropogenic sediment resuspension, bathymetric variations are also considered. PMID:25455371

  12. Storm surge forecasting for operating the Venice Flood Barrier with minimal impact on port activities

    NASA Astrophysics Data System (ADS)

    Cecconi, Giovanni

    2015-04-01

    The operation of the Venice storm barrier, due to enter into operation by the end of 2017 , is particularly demanding in terms of the required accuracy of the forecast of the max water level for the time lead of 3-6 hours. With present sea level and safeguard level established at 1.1 m a.s.l. of 1895 the barrier is expected to be operated 10 times a year to cope with an average of 5 storms with around 15 redirections of the navigation through the locks. The 5 extra closures and the 10 extra interferences with navigation are needed for compensating the present forecast uncertainty of 10 cm in the maximum storm high for the required time lead of three hours, the time needed to stop navigation before the closures of the lagoon inlets. A decision support system based on these rules have been tested along the last four year with satisfactory results in term of reliability easy of operations. The forecast is presently based on a statistical model associated with a deterministic local model; the main source of uncertainty is related to the prediction of the local wind. Due to delays in the completion of Venice local protection till 1.1 m it is expected that the population will urge a reduction of the safeguard level from 1.1m to 0.9m with an exponential increase in the number of closures with greater impact on navigation. The present acceleration in sea level rise will also contribute to the increase in the number of closures. To reduce the impact on port activity, better forecast accuracy is required together with experimenting new operational closures : e.g. activating only the northern barriers. The paper evaluate the problem and the possible solutions in terms of improving storm surge forecast and developing new schemes for partial operation of the barriers for predicted limited floods not requiring complete closures.

  13. Toxic metals in Venics lagoon sediments: Model, observation, an possible removal

    SciTech Connect

    Basu, A.; Molinaroli, E.

    1994-11-01

    We have modeled the distribution of nine toxic metals in the surface sediments from 163 stations in the Venice lagoon using published data. Three entrances from the Adriatic Sea control the circulation in the lagoon and divide it into three basins. We assume, for purposes of modeling, that Porto Marghera at the head of the Industrial Zone area is the single source of toxic metals in the Venice lagoon. In a standing body of lagoon water, concentration of pollutants at distance x from the source (C{sub 0}) may be given by C=C{sub 0}e{sup -kx} where k is the rate constant of dispersal. We calculated k empirically using concentrations at the source, and those farthest from it, that is the end points of the lagoon. Average k values (ppm/km) in the lagoon are: Zn 0.165, Cd 0.116, Hg 0.110, Cu 0.105, Co 0.072, Pb 0.058, Ni 0.008, Cr (0.011) and Fe (0.018 percent/km), and they have complex distributions. Given the k values, concentration at source (C{sub 0}), and the distance x of any point in the lagoon from the source, we have calculated the model concentrations of the nine metals at each sampling station. Tides, currents, floor morphology, additional sources, and continued dumping perturb model distributions causing anomalies (observed minus model concentrations). Positive anomalies are found near the source, where continued dumping perturbs initial boundary conditions, and in areas of sluggish circulation. Negative anomalies are found in areas with strong currents that may flush sediments out of the lagoon. We have thus identified areas in the lagoon where higher rate of sediment removal and exchange may lesson pollution. 41 refs., 4 figs., 3 tabs.

  14. Radiological impact of phosphogypsum discharged into the Venice lagoon: 222Rn

    NASA Astrophysics Data System (ADS)

    Cantaluppi, C.; Ceccotto, F.; Cianchi, A.; Fasson, A.; Degetto, S.

    2012-04-01

    For about 20 years, between the 60 's and the 80 's of the last century, in the Passo a Campalto area (Lagoon of Venice - Italy) about 400,000 m3 of phosphogypsum (PG) were deposited at the border of the lagoon and next to urban areas without any environmental control. These materials are a by-product formed during the wet processing of phosphate rocks by sulphuric acid and have a significant environmental impact due to their abundance and their chemical-physical and radiochemical characteristics. The PG contains both chemical elements, which are considered dangerous for the ecosystems and natural radionuclides whose concentrations are much higher if compared to those typical for the Earth's crust. These discarded materials caused for many years the dispersion of radionuclides in the environment due to the tidal erosion, the re-suspension of radioactive inhalable dusts, the uncontrolled radon exhalation and the bioaccumulation of some radionuclides in the lagoon environment. After a decision of the appointed authorities, the Venice Water Authority (Ministry of Infrastructure and Transport), planned a permanent safety control of the site resulting in the complete isolation of the entire volume of contaminated materials from the environmental system. The entire project was specific for the particular features of the site and it required the improvement of analytical, sampling and measurement techniques in order to verify the effectiveness of the safety action. The radon assessment, in particular the check of the effectiveness of the inhibition of radon exhalation, is part of a more complex study, covering many other aspects of the management of a permanent disposal; they will be the object of further notes. The ultimate results of this study prove the efficacy of the intervention: radon concentrations in air and exhalation values from the restored area, measured during surveys, have been proved to be well in agreement with those of non contaminated soils.

  15. Development and validation of a new Arrhythmia-Specific questionnaire in Tachycardia and Arrhythmia (ASTA) with focus on symptom burden

    PubMed Central

    2012-01-01

    Background Arrhythmias can appear with a variety of symptoms, all from vague to pronounced and handicapping symptoms. Therefore, patient-reported outcomes (PROs) concerning symptom burden are important to assess and take into consideration in the care and treatment of patients with arrhythmias. The main purpose was to develop and validate a disease-specific questionnaire evaluating symptom burden in patients with different forms of arrhythmias. Methods A literature review was conducted and arrhythmia patients were interviewed. Identified symptoms were evaluated by an expert panel consisting of cardiologists and nurses working daily with arrhythmia patients. SF-36 and Symptoms Checklist (SCL) were used in the validation of the new questionnaire Arrhythmia-Specific questionnaire in Tachycardia and Arrhythmia (ASTA). Homogeneity was evaluated with Spearman´s correlations and Cronbach´s alpha coefficient (α) was used to evaluate internal consistency. Construct validity was evaluated using item-total correlations and convergent and discriminant validity. For this, Spearman´s correlations were calculated between the ASTA symptom scale, SCL and SF-36. Concurrent validity was validated by Spearman´s correlations between the ASTA symptom scale and SCL. Results The correlations between the different items in the ASTA symptom scale showed generally sufficient homogeneity. Cronbach´s coefficient was found to be satisfactory (α = 0.80; lower bound 95 % CI for α = 0.76). Construct validity was supported by item-total correlations where all items in the symptom scale were sufficiently correlated (≥0.3). Convergent and discriminant validity was supported by the higher correlations to the arrhythmia-specific SCL compared to the generic SF-36. Concurrent validity was evaluated and there were sufficiently, but not extremely strong correlations found between the ASTA symptom scale and SCL. Conclusions The nine items of the ASTA symptom scale were found to have good

  16. Radial collapse and physical mechanism of carbon nanotube with divacancy and 5-8-5 defects

    NASA Astrophysics Data System (ADS)

    Zhang, Ya-Ping; Ling, Cui-Cui; Li, Gui-Xia; Zhu, Hai-Feng; Zhang, Meng-Yu

    2015-04-01

    By employing molecular mechanics and molecular dynamics simulations, we investigate the radial collapses and elasticities of different chiral single-walled carbon nanotubes (SWCNTs) with divacancy, and 5-8-5 defects. It is found that divacancy and 5-8-5 defect can reduce the collapse pressure (Pc) of SWCNT (10, 10) while 5-8-5 defect can greatly increase Pc of SWCNT (17, 0). For example, 5-8-5 defect can make Pc of SWCNT (17, 0) increase by 500%. A model is established to understand the effects of chirality, divacancy, and 5-8-5 defect on radial collapse of SWCNTs. The results are particularly of value for understanding the mechanical behavior of SWCNT with divacancy, and the 5-8-5 defect that may be considered as a filler of high loading composites. Project supported by the National Natural Science Foundation of China (Grant No. 11374372), Natural Science Foundation of Shandong Province, China (Grant No. ZR2014EMQ006), the Postdoctoral Science Foundation of China (Grant No. 2014M551983), the Postdoctoral Applied Research Foundation of Qingdao City, China (Grant No. 2014), the Fundamental Research Funds for the Central Universities, China (Grant Nos. 12CX04087A and 14CX02018A), and the Qingdao Science and Technology Program, China (Grant No. 14-2-4-27-jch).

  17. Thermal pollution and settlement of new tropical alien species: The case of Grateloupia yinggehaiensis (Rhodophyta) in the Venice Lagoon

    NASA Astrophysics Data System (ADS)

    Wolf, M. A.; Sfriso, A.; Moro, I.

    2014-06-01

    The Venice Lagoon has become increasingly affected by the introduction of allochthonous macroalgae mainly coming from the Indo-Pacific area. In consequence to the recent climate changes and temperature increase, such species could simply find numerous habitats suitable for their growth. One local process that contributes to water temperature changes is thermal pollution. In this study we used the DNA barcoding method to identify a new alien macroalgal species, Grateloupia yinggehaiensis Wang et Luan (Rhodophyta), found near the industrial area of Porto Marghera (Venice, Italy) hosting the Fusina thermoelectric power plant. The microclimate of this area has enabled the spread of this species native of the tropical area of the Hainan Province (China) and probably introduced in the Mediterranean Sea via shellfish transfers.

  18. Nucleotide sequence of an exceptionally long 5.8S ribosomal RNA from Crithidia fasciculata.

    PubMed

    Schnare, M N; Gray, M W

    1982-03-25

    In Crithidia fasciculata, a trypanosomatid protozoan, the large ribosomal subunit contains five small RNA species (e, f, g, i, j) in addition to 5S rRNA [Gray, M.W. (1981) Mol. Cell. Biol. 1, 347-357]. The complete primary sequence of species i is shown here to be pAACGUGUmCGCGAUGGAUGACUUGGCUUCCUAUCUCGUUGA ... AGAmACGCAGUAAAGUGCGAUAAGUGGUApsiCAAUUGmCAGAAUCAUUCAAUUACCGAAUCUUUGAACGAAACGG ... CGCAUGGGAGAAGCUCUUUUGAGUCAUCCCCGUGCAUGCCAUAUUCUCCAmGUGUCGAA(C)OH. This sequence establishes that species i is a 5.8S rRNA, despite its exceptional length (171-172 nucleotides). The extra nucleotides in C. fasciculata 5.8S rRNA are located in a region whose primary sequence and length are highly variable among 5.8S rRNAs, but which is capable of forming a stable hairpin loop structure (the "G+C-rich hairpin"). The sequence of C. fasciculata 5.8S rRNA is no more closely related to that of another protozoan, Acanthamoeba castellanii, than it is to representative 5.8S rRNA sequences from the other eukaryotic kingdoms, emphasizing the deep phylogenetic divisions that seem to exist within the Kingdom Protista. PMID:7079176

  19. Geophysical techniques in the historical center of Venice (Italy): preliminary results from HVSR and multichannel analysis of surface waves

    NASA Astrophysics Data System (ADS)

    Trevisani, Sebastiano; Rocca, Michele; Boaga, Jacopo

    2014-05-01

    This presentation aims to outline the preliminary findings related to an extensive seismic survey conducted in the historical center of Venice, Italy. The survey was conducted via noninvasive and low-cost seismic techniques based on surface waves analysis and microtremor methods, mainly using single station horizontal to vertical spectral ratio techninques (HVSR) and multichannel analysis of surface waves in passive (ReMI) and active (MASW) configurations. The importance and the fragility of the cultural heritage of Venice, coupled with its peculiar geological and geotechnical characteristics, stress the importance of a good knowledge of its geological architecture and seismic characteristics as an opportunity to improve restoration and conservation planning. Even if Venice is located in a relatively low seismic hazard zone, a local characterization of soil resonance frequencies and surficial shear waves velocities could improve the planning of engineering interventions, furnishing important information on possible local effects related to seismic amplification and possible coupling within buildings and soil resonance frequencies. In the specific we collected more than 50 HVSR single station noise measurements and several passive and active multichannel analysis of surface waves located in the historical center. In this work we report the characteristics of the conducted seismic surveys (instrumentation, sampling geometry, etc.) and the preliminary findings of our analysis. Moreover, we discuss briefly the practical issues, mainly of logistic nature, of conducting this kind of surveys in a peculiar and crowed historical center as represented by Venice urban contest. Acknowledgments Instrumentation acquired in relation to the project co-financed by Regione Veneto, POR-CRO, FESR, 2007-2013, action 1.1.1. "Supporto ad attività di ricerca, processi e reti di innovazione e alla creazione di imprese in settori a elevato contenuto tecnologico"

  20. Sedimentological, archeological and historical evidences of paleoclimatic changes during the holocene in the lagoon of Venice (Italy)

    SciTech Connect

    Bonardi, M.; Canal, E.; Cavazzoni, S.

    1997-12-31

    Sedimentological investigations and archeological and historical information have allowed to correlate paleoenvironmental and coastline variations, in the Lagoon of Venice, to climatic changes during the Holocene. In particular, we report the results of a detailed study of Holocene sediments, from salt marshes and small islands, taken above and below a level with well dated archeological findings that gave a good indication of the mean sea level.

  1. Ab initio and molecular dynamics studies of crystalline TNAD (trans-1,4,5,8-tetranitro-1,4,5,8-tetraazadecalin).

    PubMed

    Qiu, Ling; Xiao, He-Ming; Zhu, Wei-Hua; Xiao, Ji-Jun; Zhu, Wei

    2006-06-01

    The structural and electronic properties of the energetic crystal TNAD (trans-1,4,5,8-tetranitro-1,4,5,8- tetraazadecalin) have been studied using plane-wave ab initio calculations based on the density function theory method with the ultrasoft pseudopotentials. It is found that the predicted crystal structure is in good agreement with experimental data and there are strong inter- and intramolecular interactions in bulk TNAD. Band structure calculations indicate that TNAD is an insulator with the band gap of ca. 3.3 eV. The hydrostatic compression effect on TNAD has been studied in the pressure range of 0-600 GPa. The results show that a pressure less than 10 GPa does not significantly change the geometric parameters, charge distributions, and electronic bands. When the pressure is over 10 GPa, increasing the pressure determines significant changes of the geometrical and electronic structures and large broadening of the electronic bands together with a sharp decrease of the band gap. Isothermal-isobaric molecular dynamics simulations at atmospheric pressure were further performed on the TNAD crystal in the temperature range 5-500 K. Average equilibrium lattice parameters and elastic properties as functions of temperature were determined. The thermal expansion coefficients calculated for the crystal indicate anisotropic behavior with the largest expansion along the b axis. PMID:16771311

  2. Cardiac arrhythmias in hypokalemic periodic paralysis: Hypokalemia as only cause?

    PubMed

    Stunnenberg, Bas C; Deinum, Jaap; Links, Thera P; Wilde, Arthur A; Franssen, Hessel; Drost, Gea

    2014-09-01

    It is unknown how often cardiac arrhythmias occur in hypokalemic periodic paralysis (HypoPP) and if they are caused by hypokalemia alone or other factors. This systematic review shows that cardiac arrhythmias were reported in 27 HypoPP patients. Cases were confirmed genetically (13 with an R528H mutation in CACNA1S, 1 an R669H mutation in SCN4A) or had a convincing clinical diagnosis of HypoPP (13 genetically undetermined) if reported prior to the availability of genetic testing. Arrhythmias occurred during severe hypokalemia (11 patients), between attacks at normokalemia (4 patients), were treatment-dependent (2 patients), or unspecified (10 patients). Nine patients died from arrhythmia. Convincing evidence for a pro-arrhythmogenic factor other than hypokalemia is still lacking. The role of cardiac expression of defective skeletal muscle channels in the heart of HypoPP patients remains unclear. Clinicians should be aware of and prevent treatment-induced cardiac arrhythmia in HypoPP. PMID:25088161

  3. Macrolide Antibiotics and the Risk of Cardiac Arrhythmias

    PubMed Central

    Schuller, Joseph L.

    2014-01-01

    Randomized, controlled trials have demonstrated that chronic therapy with macrolide antibiotics reduces the morbidity of patients with cystic fibrosis, non–cystic fibrosis bronchiectasis, chronic obstructive pulmonary disease, and nontuberculous mycobacterial infections. Lower levels of evidence indicate that chronic macrolides are also effective in treating patients with panbronchiolitis, bronchiolitis obliterans, and rejection after lung transplant. Macrolides are known to cause torsade des pointes and other ventricular arrhythmias, and a recent observational study prompted the FDA to strengthen the Warnings and Precautions section of azithromycin drug labels. This summary describes the electrophysiological effects of macrolides, reviews literature indicating that the large majority of subjects experiencing cardiac arrhythmias from macrolides have coexisting risk factors and that the incidence of arrhythmias in absence of coexisting risk factors is very low, examines recently published studies describing the relative risk of arrhythmias from macrolides, and concludes that this risk has been overestimated and suggests an approach to patient evaluation that should reduce the relative risk and the incidence of arrhythmias to the point that chronic macrolides can be used safely in the majority of subjects for whom they are recommended. PMID:24707986

  4. Assessing short- and long-time displacements in the Venice coastland by synthetic aperture radar interferometric point target analysis

    NASA Astrophysics Data System (ADS)

    Teatini, Pietro; Strozzi, Tazio; Tosi, Luigi; Wegmüller, Urs; Werner, Charles; Carbognin, Laura

    2007-03-01

    The Venice Lagoon in Italy is a unique environment vulnerable to loss in surface elevation relative to the mean sea level. We present detailed synthetic aperture radar (SAR) interferometric analyses on persistent point targets for the historical center of Venice, the tourist area of Sottomarina, and the Zennare farmland close to the southern lagoon edge. The selected areas are characterized by different degrees of development and our analyses show the remarkable capability of SAR Interferometric Point Target Analysis (IPTA) to map land displacement rates in densely urbanized zones and to detect movement information on isolated structures with a mm/year accuracy. A detailed analysis of the time series from 1992 to 2000 provided by IPTA shows that the vertical component of the measured displacements are the superposition of a short timescale, generally seasonal, movement on the order of 1 cm that is likely related to the fluctuation of environmental variables (temperature, piezometric head in the aquifer system underlying the lagoon, sea/lagoon water level) and a long-term ground deformation associated with building construction, the geomorphology of the area, and the human development of natural resources. If Venice is confirmed to be generally stable, significant long-term subsidence on the order of 4 mm/year is detected at the Sottomarina coastland. The highest displacement rates, of up to 8-10 mm/year, are recorded in the farmland bounding the lagoon margin where the movements are found to be highly site-specific.

  5. Antiloosening ability of 5/8 inch stainless steel BSW threaded fasteners

    NASA Astrophysics Data System (ADS)

    Panja, Bikash; Das, Santanu

    2016-07-01

    Threaded fasteners are popular for temporary joining of different components due to the fact that they retain high clamping force and torque for long. However, they may loosen under vibrating conditions causing failure of the system. In this experimental work, antiloosening ability of various 5/8 inch BSW fastening elements, such as conventional nut and nylock nut with flat washer, spring washer, inside and outside serrated washers is tested with stainless steel (SS) bolts. A hybrid double nut using a simple nut and one nylock nut at the outside and a typical adhesive bonded nut with 5/8 inch BSW bolt are introduced to obtain resistance to loosening. Some hybrid double nut and adhesive bonded nut are recommended for stainless steel 5/8 inch BSW bolts under vibration.

  6. LDEF polymeric materials: 10 months versus 5.8 years of exposure

    NASA Technical Reports Server (NTRS)

    Young, Philip R.; Slemp, Wayne S.; Chang, Alice C.

    1993-01-01

    The chemical characterization of several polymeric materials which received 10 months of exposure and 5.8 years of exposure on a Row 9 Long Duration Exposure Facility (LDEF) experiment (A0134) is reported. Specimens include fluorinated ethylene propylene (FEP) teflon film, polysulfone film, and graphite fiber reinforced epoxy amd polysulfone matrix composites. The responses of these materials to the two LEO exposures are compared. The results of infrared, thermal, x-ray photoelectron, and scanning electron microscope analyses are reported. Solution property measurements of various molecular weight parameters are presented for the thermoplastic polysulfone materials. Molecular level effects attributable to exposure that were present in 10-month exposed specimens were not found in 5.8-year exposed specimens. This result suggests that increased atomic oxygen fluence toward the end of the LDEF mission may have eroded away selected environmentally induced changes in surface chemistry for 5.8-year exposure specimens.

  7. [Cardiac arrhythmias in targeted connexin deficient mice: significance for the arrhythmia field].

    PubMed

    Hagendorff, A; Plum, A

    2000-12-01

    Intercellular communication can be mediated by gap junction channels. One channel is composed of two hexameric hemichannels which consist of six polypeptide subunits called connexines (Cx). Three different connexines were documented in the cardiac myocytes: Cx40, Cx43 and Cx45. The labeling by number represents the rounded, molecular mass of the amino acid sequences given in kD. Identical connexons form homotypic channels different connexons can form heterotypic channels. Each channel type has specific properties regarding permeability and electrical conductance. Beside a typical age-dependent alignment of gap junction channels on the surface of the cardiac myocytes, regional distribution of the different connexins is different at distinct parts of the mouse heart. The ventricular working myocardium is characterized by Cx43, whereas Cx40 and Cx45 were not found in this region. In the atria as well as in the conduction system, Cx40 is the most frequently expressed. Cx45 appears to form a border zone between conductive and the surrounding working myocardium. In line with the localization and the conduction properties of distinct homotypic gap junction channels, the Cx43 deficient mouse is suitable for analysis of ventricular arrhythmias and the Cx40 deficient mouse primarily for studies of atrial arrhythmias. Increased ventricular conduction velocity and increased ventricular vulnerability were observed in the presence of a decreased number and density of Cx43 gap junction channels. This observation, however, is controversially discussed. Cx40 deficiency induces an impairment of the sinuatrial, intraatrial and atrioventricular conduction properties and is associated with an increased atrial vulnerability. Transgenic mouse models and new mapping techniques for detection of the electrical wavefront propagation provide new insights into the mechanisms of arrhythmogenesis. Geneticists, clinicians and basic researchers need to collaborate in order to explore the clinical

  8. The design and evaluation of a 5.8 ghz laptop-based radar system

    NASA Astrophysics Data System (ADS)

    Teng, Kevin Chi-Ming

    This project involves design and analysis of a 5.8 GHz laptop-based radar system. The radar system measures Doppler, ranging and forming Synthetic Aperture Radar (SAR) images utilizing Matlab software provided from MIT Open Courseware and performs data acquisition and signal processing. The main purpose of this work is to bring new perspective to the existing radar project by increasing the ISM band frequency from 2.4 GHz to 5.8 GHz and to carry out a series of experiments on the implementation of the radar kit. Demonstrating the radar at higher operating frequency is capable of providing accurate data results in Doppler, ranging and SAR images.

  9. 5. 8 GHz ophthalmic microwave applicator for treatment of choroidal melanoma

    SciTech Connect

    Finger, P.T.; Packer, S.; Svitra, P.; Paglione, R.W.; Albert, D.M.; Chess, J.

    1983-01-01

    We report on the use of a 5.8 GHz microwave applicator to treat choroidal melanoma (Greene) in rabbits. The physical requirements needed to treat these intraocular tumors are quite different from those encountered elsewhere in the body. From a trans-scleral approach the penetration needed is minimal (5 to 10 mm.). The fibrous sclera is the only structure between the heat source and the tumor. The sclera has a relatively low water content when compared to tumor. This fact in addition to the frequency dependent interactions of tissue and electromagnetic radiation, results in an advantage to the use of the 5.8 GHz microwave device in treating intraocular malignancies.

  10. Remediation of heavy metal contaminated sites in the Venice lagoon and conterminous areas (Northern Italy)

    NASA Astrophysics Data System (ADS)

    Bini, Claudio; Wahsha, Mohammad; Fontana, Silvia; Maleci, Laura

    2013-04-01

    The lagoon of Venice and the conterminous land are affected by heavy contamination of anthropogenic origin, and for this reason the whole area has been classified as site of national interest, and must be restored. Heavy metals (As, Cd, Cr, Cu, Hg, Mn, Pb, Sb, Se, Zn) and organic compounds (IPA, PCB, Dioxine) have been identified as the main contaminants at various sites, owing to agriculture and industrial wastes discharged on soils and convoyed to the lagoon. Five case studies of soil remediation are here reported. S. Giuliano is a former palustrine area reclaimed since the 60's with various human transported materials (HTM). In this area, hot spots overpassing the reference limits for residential and green areas have been recorded for Cd, Cu, Pb, Zn and IPA. Campalto is a site bordering the Venice lagoon and subjected to oscillating water level, that enhances metal mobility; diffuse contamination by heavy metals, particularly Pb, has been recorded at this site, utilized since 30 years for military and sport (skate) activities. Marghera is dramatically famous for its numerous factories and for oil refineries that affected the lagoon sediments since the 50's. Sediments proved heavily contaminated by As (up to 137 mgkg-1), Cd (57 mgkg-1), Hg (30mgkg-1), Ni, Pb (700 mgkg-1), Zn (5818 mgkg-1). Murano is a small island where many glass factories (the most famous all over the world) are running since XIII century. Glass is stained with several metals and, moreover, some substances are used to regulate fusion temperature, purity, etc., and therefore the surrounding environment is heavily contaminated by these substances. Mean concentrations of As (429 mgkg-1), Cd (1452 mgkg-1), Pb (749 mgkg-1), Zn (1624 mgkg-1), Se (341 mgkg-1), Sb (74 mgkg-1) widely overpass the reference values for both residential and industrial areas in national guidelines. Molo Serbatoi is a former oil container currently under restoration in the port of Venice. Soil contamination by As, Hg, Zn and

  11. Natural versus anthropogenic subsidence of Venice: investigation of the present occurrence by PSI

    NASA Astrophysics Data System (ADS)

    Tosi, Luigi; Strozzi, Tazio; Teatini, Pietro

    2014-05-01

    We detected land displacements of Venice by Persistent Scatterer Interferometry (PSI) using ERS and ENVISAT C-band and TerraSAR-X and COSMO-SkyMed X-band acquisitions over the periods 1992-2010 and 2008-2011, respectively. PSI provides the cumulative land displacements (natural plus anthropogenic) of the investigated area independently of the radar band. The natural subsidence rate depends on the reference period and, due to the present elevation of Venice with respect to the sea level, it is much more interesting for the city to evaluate the natural displacement over the last few decades, i.e. the present natural land subsidence, than that averaged over geological periods. Concerning anthropogenic land subsidence the contribution due to activities characterized by large scale and long term effects, e.g., that caused by groundwater withdrawals, ended a few decades ago. Today, the anthropogenic component of the land subsidence is only due to local, short-time interventions such as restoration works and inherent deformations of historical structures. By reason of the larger observation period, the C-band sensors were used to quantify the long-term movements, i.e. the subsidence component primarily ascribed to natural processes. The high resolution, short revisiting time X-band satellites reveal a high effectiveness to monitor short-time movements as those induced by human activities. The statistical analysis of the displacement distributions measured by PSI points out that the average rates, i.e. the natural component of the subsidence, are almost equal with the C-band and X-band satellites. Conversely, the standard deviation with X-band acquisitions (1.6 mm/yr) is characterized by a value significantly larger than that detected with C-band images (0.7 mm/yr). The larger X-band variability superposes to a background velocity similar to that given by ERS/ENVISAT. It is reasonable to assume that the difference between the movements provided by ERS/ENVISAT and Terra

  12. Next Generation Sequencing for the Diagnosis of Cardiac Arrhythmia Syndromes

    PubMed Central

    Lubitz, Steven A.; Ellinor, Patrick T.

    2015-01-01

    Inherited arrhythmia syndromes are collectively associated with substantial morbidity, yet our understanding of the genetic architecture of these conditions remains limited. Recent technological advances in DNA sequencing have led to the commercialization of genetic testing now widely available in clinical practice. In particular, next generation sequencing allows the large-scale and rapid assessment of entire genomes. Although next generation sequencing represents a major technological advance, it has introduced numerous challenges with respect to the interpretation of genetic variation, and has opened a veritable floodgate of biological data of unknown clinical significance to practitioners. In this review, we discuss current genetic testing indications for inherited arrhythmia syndromes, broadly outline characteristics of next generation sequencing techniques, and highlight challenges associated with such testing. We further summarize future directions that will be necessary to address to enable the widespread adoption of next generation sequencing in the routine management of patients with inherited arrhythmia syndromes. PMID:25625719

  13. Psychological Distress and Arrhythmia: Risk Prediction and Potential Modifiers

    PubMed Central

    Peacock, James; Whang, William

    2014-01-01

    The connection between the heart and the brain has long been anecdotally recognized but systematically studied only relatively recently. Cardiac arrhythmias, especially sudden cardiac death, remain a major public health concern and there is mounting evidence that psychological distress plays a critical role as both a predictor of high-risk cardiac substrate and as an inciting trigger. The transient, unpredictable nature of emotions and cardiac arrhythmias have made their study challenging, but evolving technologies in monitoring and imaging along with larger epidemiological data sets have encouraged more sophisticated studies examining this relationship. Here we review the research on psychological distress including anger, depression and anxiety on cardiac arrhythmias, insights into proposed mechanisms, and potential avenues for future research. PMID:23621968

  14. Electrocardiographic abnormalities and cardiac arrhythmias in chronic obstructive pulmonary disease.

    PubMed

    Goudis, Christos A; Konstantinidis, Athanasios K; Ntalas, Ioannis V; Korantzopoulos, Panagiotis

    2015-11-15

    Chronic obstructive pulmonary disease (COPD) is independently associated with an increased burden of cardiovascular disease. Besides coronary artery disease (CAD) and congestive heart failure (CHF), specific electrocardiographic (ECG) abnormalities and cardiac arrhythmias seem to have a significant impact on cardiovascular prognosis of COPD patients. Disturbances of heart rhythm include premature atrial contractions (PACs), premature ventricular contractions (PVCs), atrial fibrillation (AF), atrial flutter (AFL), multifocal atrial tachycardia (MAT), and ventricular tachycardia (VT). Of note, the identification of ECG abnormalities and the evaluation of the arrhythmic risk may have significant implications in the management and outcome of patients with COPD. This article provides a concise overview of the available data regarding ECG abnormalities and arrhythmias in these patients, including an elaborated description of the underlying arrhythmogenic mechanisms. The clinical impact and prognostic significance of ECG abnormalities and arrhythmias in COPD as well as the appropriate antiarrhythmic therapy and interventions in this setting are also discussed. PMID:26218181

  15. Laboratory Markers of Ventricular Arrhythmia Risk in Renal Failure

    PubMed Central

    2014-01-01

    Sudden cardiac death continues to be a major public health problem. Ventricular arrhythmia is a main cause of sudden cardiac death. The present review addresses the links between renal function tests, several laboratory markers, and ventricular arrhythmia risk in patients with renal disease, undergoing or not hemodialysis or renal transplant, focusing on recent clinical studies. Therapy of hypokalemia, hypocalcemia, and hypomagnesemia should be an emergency and performed simultaneously under electrocardiographic monitoring in patients with renal failure. Serum phosphates and iron, PTH level, renal function, hemoglobin and hematocrit, pH, inflammatory markers, proteinuria and microalbuminuria, and osmolarity should be monitored, besides standard 12-lead ECG, in order to prevent ventricular arrhythmia and sudden cardiac death. PMID:24982887

  16. Controlled Exposures to Air Pollutants and Risk of Cardiac Arrhythmia

    PubMed Central

    Watts, Simon J.; Hunter, Amanda J.; Shah, Anoop S.V.; Bosson, Jenny A.; Unosson, Jon; Barath, Stefan; Lundbäck, Magnus; Cassee, Flemming R.; Donaldson, Ken; Sandström, Thomas; Blomberg, Anders; Newby, David E.; Mills, Nicholas L.

    2014-01-01

    Background: Epidemiological studies have reported associations between air pollution exposure and increases in cardiovascular morbidity and mortality. Exposure to air pollutants can influence cardiac autonomic tone and reduce heart rate variability, and may increase the risk of cardiac arrhythmias, particularly in susceptible patient groups. Objectives: We investigated the incidence of cardiac arrhythmias during and after controlled exposure to air pollutants in healthy volunteers and patients with coronary heart disease. Methods: We analyzed data from 13 double-blind randomized crossover studies including 282 participants (140 healthy volunteers and 142 patients with stable coronary heart disease) from whom continuous electrocardiograms were available. The incidence of cardiac arrhythmias was recorded for each exposure and study population. Results: There were no increases in any cardiac arrhythmia during or after exposure to dilute diesel exhaust, wood smoke, ozone, concentrated ambient particles, engineered carbon nanoparticles, or high ambient levels of air pollution in either healthy volunteers or patients with coronary heart disease. Conclusions: Acute controlled exposure to air pollutants did not increase the short-term risk of arrhythmia in participants. Research employing these techniques remains crucial in identifying the important pathophysiological pathways involved in the adverse effects of air pollution, and is vital to inform environmental and public health policy decisions. Citation: Langrish JP, Watts SJ, Hunter AJ, Shah AS, Bosson JA, Unosson J, Barath S, Lundbäck M, Cassee FR, Donaldson K, Sandström T, Blomberg A, Newby DE, Mills NL. 2014. Controlled exposures to air pollutants and risk of cardiac arrhythmia. Environ Health Perspect 122:747–753; http://dx.doi.org/10.1289/ehp.1307337 PMID:24667535

  17. Risk of land degradation due to saltwater intrusion along the Venice coastland, Italy

    NASA Astrophysics Data System (ADS)

    Teatini, P.; Manoli, G.; Scudiero, E.; Deiana, R.; Perri, M.; Braga, F.; Tosi, L.; Putti, M.; Morari, F.

    2012-12-01

    The southern portion of the Venice coastland includes a very precarious environment. Due to an elevation down to 4 m below msl, the Venice Lagoon and Adriatic Sea proximity, and the encroachment of seawater from the mouth of the river network up to 20 km inland, salt contamination of land and groundwater is a severe problem that is seriously impacting the farmland productivity. An interdisciplinary multi-scale research is ongoing with the aim of understanding the contamination process, quantifying the effect of the saltwater intrusion of the crop production, and proposing possible mitigation strategies. A 25 ha basin cultivated with maize crop and representative of the area has been deeply monitored at various scales ranging from a few square meter plots up to the whole basin. Geophysical surveys, lab testing on soil and water samples, continuous measurements of hydrological parameters, physiological crop parameters, proximal sensing and multi-spectral remote sensing acquisitions, together with precise crop yield distribution were performed and acquired from 2010 to 2012. Geomorphological investigations, seismic and geo-electrical surveys combined with salt concentration measurements in the surficial waterbodies and groundwater (down to 10 m deep) are used to delineate the major pathways of seawater intrusion. Relationships existing between soil, water, crop factors and crop yield were identified, helping to assess plant stress at both the canopy and landscape level. The dataset is now used to set-up a three-dimensional numerical model of saturated/unsaturated water dynamics coupled with a crop-growth model. The model is applied at the basin scale to investigate the effects of water stress and soil contamination on the crop production. Once calibrated on hydrological records (e.g., groundwater levels, capillary pressure, etc.), crop growth, and yield production, the model will be applied to investigate expected scenarios related with the change of natural

  18. Benthic macrofauna changes in areas of Venice lagoon populated by seagrasses or seaweeds.

    PubMed

    Sfriso, A; Birkemeyer, T; Ghetti, P F

    2001-10-01

    Two areas of the Venice lagoon populated by seagrasses (three stations covered by Cymodocea nodosa (Ucria) Asherson, Zostera marina Linnaeus, Zostera noltii Hornemann) or seaweeds (two stations: one covered by Ulva rigida C. Agardh and another at present without seaweed biomass) were monitored by means of six surveys over a year in order to study macrofaunal composition and seasonal changes. The seagrass stations showed a mean species richness (28-30 S m(-2)), individual abundance (1854-4018 N m(-2)) and biomass (22.3-37.7 g m(-2) ash-free-dry-weight, AFDW) ca. 3-8 times higher than those populated by seaweeds (10-15 S m(-2), 494-1395 N m(-2) and 5.6-13.7 g m(-2) AFDW). Differences among seagrass or seaweed stations were much lower. The Ulva-dominated station showed a macrofauna completely different both from the other stations and the communities recorded ca. 30 years ago, before the prolific growth of Ulva. In this station, frequent biomass decompositions and anoxic crises created critical conditions for life favouring organisms with reduced life cycles, younger individuals and the epifaunal species instead of the infaunal ones. In particular, Ulva grazers and scrapers such as Gammarus aequicauda Stock and Gibbula adriatica Philippi were found to be by far the most abundant species, whereas the taxa characteristic of the associations found in the past, in the presence of seagrasses or seaweeds and typical of low eutrophicated environments, appear strongly reduced. Marked differences in the macrophyte dominance and in the bio-physico-chemical variables which characterise the main environmental conditions of the Venice lagoon support the different distribution and composition of macrofaunal communities. Seaweed stations appear mainly governed by the seasonal cycles of these un-rooted macrophytes which, by alternating periods of production and decomposition, are responsible for the drastic reduction of macrofauna biodiversity and biomass. Conversely, seagrass

  19. Radar-driven High-resolution Hydrometeorological Forecasts of the 26 September 2007 Venice flash flood

    NASA Astrophysics Data System (ADS)

    Massimo Rossa, Andrea; Laudanna Del Guerra, Franco; Borga, Marco; Zanon, Francesco; Settin, Tommaso; Leuenberger, Daniel

    2010-05-01

    Space and time scales of flash floods are such that flash flood forecasting and warning systems depend upon the accurate real-time provision of rainfall information, high-resolution numerical weather prediction (NWP) forecasts and the use of hydrological models. Currently available high-resolution NWP model models can potentially provide warning forecasters information on the future evolution of storms and their internal structure, thereby increasing convective-scale warning lead times. However, it is essential that the model be started with a very accurate representation of on-going convection, which calls for assimilation of high-resolution rainfall data. This study aims to assess the feasibility of using carefully checked radar-derived quantitative precipitation estimates (QPE) for assimilation into NWP and hydrological models. The hydrometeorological modeling chain includes the convection-permitting NWP model COSMO-2 and a hydrologic-hydraulic models built upon the concept of geomorphological transport. Radar rainfall observations are assimilated into the NWP model via the latent heat nudging method. The study is focused on 26 September 2007 extreme flash flood event which impacted the coastal area of north-eastern Italy around Venice. The hydro-meteorological modeling system is implemented over the Dese river, a 90 km2 catchment flowing to the Venice lagoon. The radar rainfall observations are carefully checked for artifacts, including beam attenuation, by means of physics-based correction procedures and comparison with a dense network of raingauges. The impact of the radar QPE in the assimilation cycle of the NWP model is very significant, in that the main individual organized convective systems were successfully introduced into the model state, both in terms of timing and localization. Also, incorrectly localized precipitation in the model reference run without rainfall assimilation was correctly reduced to about the observed levels. On the other hand, the

  20. Saltwater contamination in the Venice Lagoon margin. Effects on soil productivity

    NASA Astrophysics Data System (ADS)

    Teatini, P.; Scudiero, E.; Braga, F.; Piragnolo, D.; Deiana, R.; Manoli, G.; Berti, A.; Morari, F.

    2011-12-01

    The Venice watershed includes a very precarious coastal environment subject to both natural and anthropogenic changes with a significant and economically important fraction of the coastal farmland presently below mean sea level. In the hydrogeological context of the Venice coastland, a large risk of saltwater contamination characterizes the southernmost area because of the geomorphological setting of the coastal plain. Salt contamination is influenced also by the activity of several pumping stations used to keep drained the area, groundwater withdrawals, irrigation and freshwater releases during summer dry months. The impact of salt intrusion from the salty water bodies on soil productivity has been studied in the years 2010-2011. In a 25 ha basin cultivated with maize crop, soil salinity (electrical conductivity 1:2) and the main physical-chemical properties of the soil (e.g. texture, pH, organic carbon and CSC) were measured along the 1.5 m soil profile in 120 positions. Maps of apparent electrical conductivity (ECa) at three different investigation depths (0 - 0.75 m; 0-1.50 m; 0- 6.00 m) were also obtained in April 2010 and April 2011 with a CMD electromagnetic conductivity meter (GF Instruments) associated to a DGPS. During the 2-year period some physiological crop parameters, in particular leaf reflectance (i.e. Spectrascan, Photoresearch) and leaf ions content were monitored across the study area. Moreover, maps of NDVI were obtained by proximal sensing (three dates each year) using an active spectral radiometer (Crop Circle, Holland Scientific) and remote sensing acquiring WorldView-2 satellite images at the end of July 2010 and beginning of July 2011. Finally, maps of the crop yield were obtained at the end of the growing seasons by a yield mapping system mounted on a combine harvester. Relationships existing between soil, crop factors and crop yield were identified applying a multivariate spatial model, helping to assess plant stress at both the canopy

  1. Innovation in the diagnosis and treatment of cardiac arrhythmias.

    PubMed

    Friedman, Paul A; Eldar, Michal; Ovsyshcher, I Eli

    2012-08-01

    The 11th International Dead Sea Symposium on Cardiac Arrhythmias and Device Therapy - the 20th Anniversary of the meeting - was held in Jerusalem, Israel on the 26-29 February 2012. The global meeting was conducted with the goal of providing a venue for a multidisciplinary approach to exchange knowledge in all areas related to arrhythmia care. In addition to presentations of original research and keynote lectures, special educational sessions were offered that included hands-on anatomy training and interesting case presentations. A series of innovations sessions included presentations by start-up companies and inventors, leveraging the venue's entrepreneurial environment. PMID:23030286

  2. Into Adolescence: Actions for Wellpower. A Curriculum for Grades 5-8. Contemporary Health Series.

    ERIC Educational Resources Information Center

    Waters, Mae; Hocker, Anita

    This module on wellness includes eight lessons, and is oriented toward middle school students in grades 5-8. Students choose partners to support them in achieving their goals for improving health in several areas. In lesson 1, health and wellness are defined. Students are introduced to a wellness continuum and the physical, mental/emotional, and…

  3. The Columbia River: Its Future and You. Teacher's Manual for Grades 5-8.

    ERIC Educational Resources Information Center

    Frost, Marcia

    Designed as a part of a multidisciplinary set of curricula and educational materials on the Columbia River, this teacher's guide focuses on the many uses of the river and the conflicts arising from those uses. This unit's major purpose is to help students in grades 5-8 to start thinking about how the resources of the Columbia River should be…

  4. C.T.B.S. Testing. Spring 1982 District Report, 5, 8, and 11.

    ERIC Educational Resources Information Center

    O'Neal, Sandra

    Each spring the Comprehensive Tests of Basic Skills (CTBS) are administered to grades 5, 8, and 11 throughout New Mexico as part of the State Department of Education mandated assessment program. This report contains information regarding Albuquerque Public Schools' results on the 1982 CTBS. A new form of the CTBS was selected for testing fifth and…

  5. Chemistry of 5,8-dihydroxy-[1,4]-naphtoquinone, a key chromophore in aged cellulosics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    5,8-Dihydroxy-[1,4]-naphthoquinone (DHNQ) is one of the key chromophores found in aged cellulosics. Cellulose aging and yellowing as well as bleaching of cellulosic materials are key processes in the pulp and paper industries and have considerable economic importance: the knowledge of the general re...

  6. Earth Science Supplement to the Syllabus, Part 2, Topics 5-8, 1970 Edition. 1974 Reprint.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    This document contains investigation topics 5-8 in the earth science course developed by the University of the State of New York for secondary schools. Topics include energy in earth processes, insulation and the earth's surface, energy exchanges in the atmosphere, moisture and energy budgets, and environmental change. Each topic is preceded by…

  7. Into Adolescence: Enhancing Self-Esteem. A Curriculum for Grades 5-8. Contemporary Health Series.

    ERIC Educational Resources Information Center

    Zevin, Dale; McPherson, Carole

    This book is a 10-lesson module for grades 5-8, designed to increase students' awareness of self-esteem as a dynamic, ever-changing component in their lives. Beginning with a "Full Esteem Ahead" lesson to help students identify high and low self-esteem behaviors, this module gives teachers specific instructional strategies for guiding students…

  8. Temporal distribution of intertidal macrozoobenthic assemblages in a Nanozostera noltii-dominated area (Lagoon of Venice).

    PubMed

    Tagliapietra, D; Pessa, G; Cornello, M; Zitelli, A; Magni, P

    2016-03-01

    We describe the temporal distribution of intertidal macrozoobenthic assemblages in a small marsh pond of the Lagoon of Venice colonized by the seagrass Nanozostera noltii (Hornemman) Tomlinson et Posluzny. Three stations ranging in the degree of N. noltii cover were selected about 100 m apart and sampled 9 times at regular intervals from March 1996 to March 1997. We applied the concepts of resistance and resilience to "natural stress" (e.g. extent of protection from seagrass meadows, exposure of macrozoobenthic assemblages to high temperatures in summer) with the aim to assess the stability of a community along a gradient of seagrass coverage. Results showed that the most structured and taxa-rich macrozoobenthic assemblage occurred at the station covered by a continuous stand of N. noltii, where permanent taxa (i.e. found in 100% of samples) were almost double than those found at the other stations. During the annual cycle, the macrozoobenthic assemblages showed a cyclical pattern, with temporal fluctuations increasing as they moved further away from the seagrass beds. We propose the role of N. noltii offering structural complexity and stability as the more probable explanation to the observed differences between stations in the intertidal assemblages. PMID:26748407

  9. Understanding the association of Escherichia coli with diverse macroalgae in the lagoon of Venice

    PubMed Central

    Quero, Grazia M.; Fasolato, Luca; Vignaroli, Carla; Luna, Gian Marco

    2015-01-01

    Recent studies provided evidence that the macroalga Cladopohora in lakes hosts associated Escherichia coli, with consequences on the environmental and human health. We expanded these investigations to other macroalgae (Ulva spp., Sargassum muticum and Undaria pinnatifida) widespread in the lagoon of Venice (Italy). Attached E. coli were abundant, accounting up to 3,250 CFU gram−1 of alga. Macroalgal-associated isolates belonged to all E. coli phylogroups, including pathogenic ones, and to Escherichia cryptic clades. Attached E. coli showed potential to grow even at in situ temperature on macroalgal extracts as only source of carbon and nutrients, and ability to produce biofilm in vitro. The genotypic diversity of the attached isolates was high, with significant differences between algae and the overlying water. Our evidences suggest that attached populations consist of both resident and transient strains, likely resulting from the heterogeneous input of fecal bacteria from the city. We report that cosmopolitan and invasive macroalgae may serve as source of E. coli, including pathogenic genotypes, and that this habitat can potentially support their growth. Considering the global diffusion of the macroalgae here studied, this phenomenon is likely occurring in other coastal cities worldwide and deserves further investigations from either the sanitary and ecological perspectives. PMID:26043415

  10. A proposed integrated bioindex for the macrofouling biocoenosis of hard substrata in the lagoon of Venice

    NASA Astrophysics Data System (ADS)

    Cima, Francesca; Ballarin, Loriano

    2013-09-01

    Bioindices are often employed to evaluate the ecological status of an unstable habitat such as a lagoon. However, no bioindex to date has considered the macrofouling biocoenosis of hard substrata, which is characterised by a higher biodiversity than that of the benthic communities of soft substrata. We analysed the progression of the hard-substratum biocoenosis at two stations located in the southern basin of the lagoon of Venice using data collected monthly from artificial panels that were immersed continually for a period of one year. Our goal was to develop an integrated specific bioindex, according to the objectives of the Water Framework Directive (WFD) in Europe, that is easy to calculate and provides a useful and immediate value for the ecological status on a logarithmic scale from 1 to 10. The bioindex proposed here takes into account species richness, covering area, and the Q-values of important physico-chemical parameters (e.g., pH, salinity, temperature). To validate the bioindex, our sampling campaign was repeated for an additional year at the two previous stations and a third station in the central basin that had different hydrodynamic features and was subject to greater anthropogenic impact. The ecological status of the third station was "poor-to-moderate", in contrast to the "good" status of the two stations in the southern basin. Seasonal changes in the bioindex values provide useful information on environmental changes because they indicate the moment of an ecological crisis as well as its causes and long-term effects.

  11. Understanding the association of Escherichia coli with diverse macroalgae in the lagoon of Venice.

    PubMed

    Quero, Grazia M; Fasolato, Luca; Vignaroli, Carla; Luna, Gian Marco

    2015-01-01

    Recent studies provided evidence that the macroalga Cladopohora in lakes hosts associated Escherichia coli, with consequences on the environmental and human health. We expanded these investigations to other macroalgae (Ulva spp., Sargassum muticum and Undaria pinnatifida) widespread in the lagoon of Venice (Italy). Attached E. coli were abundant, accounting up to 3,250 CFU gram(-1) of alga. Macroalgal-associated isolates belonged to all E. coli phylogroups, including pathogenic ones, and to Escherichia cryptic clades. Attached E. coli showed potential to grow even at in situ temperature on macroalgal extracts as only source of carbon and nutrients, and ability to produce biofilm in vitro. The genotypic diversity of the attached isolates was high, with significant differences between algae and the overlying water. Our evidences suggest that attached populations consist of both resident and transient strains, likely resulting from the heterogeneous input of fecal bacteria from the city. We report that cosmopolitan and invasive macroalgae may serve as source of E. coli, including pathogenic genotypes, and that this habitat can potentially support their growth. Considering the global diffusion of the macroalgae here studied, this phenomenon is likely occurring in other coastal cities worldwide and deserves further investigations from either the sanitary and ecological perspectives. PMID:26043415

  12. Understanding the association of Escherichia coli with diverse macroalgae in the lagoon of Venice

    NASA Astrophysics Data System (ADS)

    Quero, Grazia M.; Fasolato, Luca; Vignaroli, Carla; Luna, Gian Marco

    2015-06-01

    Recent studies provided evidence that the macroalga Cladopohora in lakes hosts associated Escherichia coli, with consequences on the environmental and human health. We expanded these investigations to other macroalgae (Ulva spp., Sargassum muticum and Undaria pinnatifida) widespread in the lagoon of Venice (Italy). Attached E. coli were abundant, accounting up to 3,250 CFU gram-1 of alga. Macroalgal-associated isolates belonged to all E. coli phylogroups, including pathogenic ones, and to Escherichia cryptic clades. Attached E. coli showed potential to grow even at in situ temperature on macroalgal extracts as only source of carbon and nutrients, and ability to produce biofilm in vitro. The genotypic diversity of the attached isolates was high, with significant differences between algae and the overlying water. Our evidences suggest that attached populations consist of both resident and transient strains, likely resulting from the heterogeneous input of fecal bacteria from the city. We report that cosmopolitan and invasive macroalgae may serve as source of E. coli, including pathogenic genotypes, and that this habitat can potentially support their growth. Considering the global diffusion of the macroalgae here studied, this phenomenon is likely occurring in other coastal cities worldwide and deserves further investigations from either the sanitary and ecological perspectives.

  13. Road Asphalt Pavements Analyzed by Airborne Thermal Remote Sensing: Preliminary Results of the Venice Highway

    PubMed Central

    Pascucci, Simone; Bassani, Cristiana; Palombo, Angelo; Poscolieri, Maurizio; Cavalli, Rosa

    2008-01-01

    This paper describes a fast procedure for evaluating asphalt pavement surface defects using airborne emissivity data. To develop this procedure, we used airborne multispectral emissivity data covering an urban test area close to Venice (Italy).For this study, we first identify and select the roads' asphalt pavements on Multispectral Infrared Visible Imaging Spectrometer (MIVIS) imagery using a segmentation procedure. Next, since in asphalt pavements the surface defects are strictly related to the decrease of oily components that cause an increase of the abundance of surfacing limestone, the diagnostic absorption emissivity peak at 11.2μm of the limestone was used for retrieving from MIVIS emissivity data the areas exhibiting defects on asphalt pavements surface.The results showed that MIVIS emissivity allows establishing a threshold that points out those asphalt road sites on which a check for a maintenance intervention is required. Therefore, this technique can supply local government authorities an efficient, rapid and repeatable road mapping procedure providing the location of the asphalt pavements to be checked.

  14. Mind the Costs: Rescaling and Multi-Level Environmental Governance in Venice Lagoon

    NASA Astrophysics Data System (ADS)

    Roggero, Matteo; Fritsch, Oliver

    2010-07-01

    Competences over environmental matters are distributed across agencies at different scales on a national-to-local continuum. This article adopts a transaction costs economics perspective in order to explore the question whether, in the light of a particular problem, the scale at which a certain competence is attributed can be reconsidered. Specifically, it tests whether a presumption of least-cost operation concerning an agency at a given scale can hold. By doing so, it investigates whether the rescaling of certain tasks, aiming at solving a scale-related problem, is likely to produce an increase in costs for day-to-day agency operations as compared to the status quo. The article explores such a perspective for the case of Venice Lagoon. The negative aspects of the present arrangement concerning fishery management and morphological remediation are directly linked to the scale of the agencies involved. The analysis suggests that scales have been chosen correctly, at least from the point of view of the costs incurred to the agencies involved. Consequently, a rescaling of those agencies does not represent a viable option.

  15. Postmortem interval (PMI) determined by study sarcophagous biocenoses: three cases from the province of Venice (Italy).

    PubMed

    Turchetto, M; Lafisca, S; Costantini, G

    2001-08-15

    This paper presents and discusses three cases of cadavers found, unburied, in the province of Venice, Northern Italy. In each case, all insect species playing some role in carrion decay processes, both sarcophagous and their predators, found on or in the bodies, were collected and determined. In one case, many larvae of the black soldier fly, Hermetia illucens L. (Diptera: Stratiomyidae) were found and are reported, for the first time in Italy, as necrophagous. Experimental breeding of some fly species was also carried out in controlled temperature and humidity conditions. In particular, it was of interest to know how the Neotropical black soldier fly modified its life-cycle to adapt to a temperate climate. It was thus possible to establish the rate of larval growth and timing of pupation, emergence, oviposition and hatching in various external conditions. The postmortem interval (PMI) established by identifying the life-cycle stages of dipterofauna were later confirmed in all cases through police investigations and the results of forensic analyses. PMID:11457605

  16. Histopathology and stress biomarkers in the clam Venerupis philippinarum from the Venice Lagoon (Italy).

    PubMed

    Boscolo Papo, Michele; Bertotto, Daniela; Quaglio, Francesco; Vascellari, Marta; Pascoli, Francesco; Negrato, Elena; Binato, Giovanni; Radaelli, Giuseppe

    2014-07-01

    The aim of this study was to evaluate the histomorphology and the stress response in the bivalve Venerupis philippinarum sampled in four differently polluted sites of the Venice Lagoon (Palude del Monte, Marghera, Ca' Roman and Val di Brenta). This species is often used as bioindicator of environmental pollution since it can bioaccumulate a large variety of pollutants because of its filter feeding. Chemical analyses for heavy metals (Cd, Cu, Hg and Pb) and polycyclic aromatic hydrocarbons (PAHs) were performed on whole soft tissues of V. philippinarum. The histological evaluation of clams revealed the presence of Perkinsus sp. infection in animals from all sites, although a very high prevalence of parasites was evidenced in clams from Ca' Roman. Perkinsus sp. were systemically distributed in the mantle, in the intestine and digestive gland, in gonads and gills. The trophozoites of Perkinsus sp. were found isolated or in cluster surrounded by a heavy hemocitical response. Haemocytes always exhibited an immunopositivity to cytochrome P4501A (CYP1A), heat shock protein 70 (HSP70), 4-hydroxy-2-nonenal (HNE) and nitrotyrosine (NT) antibodies. The digestive gland of animals from Palude del Monte showed the highest malondialdehyde (MDA) concentration, whereas clams from Ca' Roman exhibited the highest quantity of metallothioneins. PMID:24795081

  17. Chronic Arrhythmias in the Setting of Heterotaxy: Differences between Right and Left Isomerism.

    PubMed

    Loomba, Rohit S; Willes, Richard J; Kovach, Joshua R; Anderson, Robert H

    2016-01-01

    So-called heterotaxy affects lateralization of the thoracic and abdominal organs. Congenital malformations may be present in one of several organ systems. Cardiac involvement includes both structural and conduction abnormalities. Data regarding arrhythmias in heterotaxy come from case reports and small case series. We pooled available data to further characterize arrhythmias in heterotaxy. A systematic review of the literature for manuscripts describing arrhythmias in heterotaxy patients was conducted. Databases including PubMed, EMBASE, and Ovid were searched. Studies describing arrhythmias in patients with heterotaxy were included if they were in English and presented characteristics of the arrhythmias. Arrhythmia characteristics were abstracted and are presented as pooled data. Freedom from arrhythmia by age was then analyzed using Kaplan-Meier analysis. A total of 19 studies with 121 patients were included in the pooled analysis. Those with right isomerism were found to be more likely to have atrial flutter, atrial tachycardia, junctional tachycardia, and ventricular tachycardia. Those with left isomerism were more likely to have atrioventricular block, intraventricular conduction delay, sick sinus syndrome, and atrioventricular nodal reentry tachycardia. Median age of onset for all arrhythmias was 4 years with no difference by specific arrhythmia or isomerism. Those with right and left isomerism are at risk for different arrhythmias but are likely to develop arrhythmias at the same age. Those with left isomerism are more likely to require pacemaker placement due to atrioventricular block. Understanding these differences allows for focused surveillance of development of these arrhythmias. PMID:26219620

  18. 21 CFR 870.1025 - Arrhythmia detector and alarm (including ST-segment measurement and alarm).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Arrhythmia detector and alarm (including ST... Diagnostic Devices § 870.1025 Arrhythmia detector and alarm (including ST-segment measurement and alarm). (a) Identification. The arrhythmia detector and alarm device monitors an electrocardiogram and is designed to...

  19. 21 CFR 870.1025 - Arrhythmia detector and alarm (including ST-segment measurement and alarm).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Arrhythmia detector and alarm (including ST... Diagnostic Devices § 870.1025 Arrhythmia detector and alarm (including ST-segment measurement and alarm). (a) Identification. The arrhythmia detector and alarm device monitors an electrocardiogram and is designed to...

  20. 21 CFR 870.1025 - Arrhythmia detector and alarm (including ST-segment measurement and alarm).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Arrhythmia detector and alarm (including ST... Diagnostic Devices § 870.1025 Arrhythmia detector and alarm (including ST-segment measurement and alarm). (a) Identification. The arrhythmia detector and alarm device monitors an electrocardiogram and is designed to...

  1. 21 CFR 870.1025 - Arrhythmia detector and alarm (including ST-segment measurement and alarm).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Arrhythmia detector and alarm (including ST... Diagnostic Devices § 870.1025 Arrhythmia detector and alarm (including ST-segment measurement and alarm). (a) Identification. The arrhythmia detector and alarm device monitors an electrocardiogram and is designed to...

  2. 21 CFR 870.1025 - Arrhythmia detector and alarm (including ST-segment measurement and alarm).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Arrhythmia detector and alarm (including ST... Diagnostic Devices § 870.1025 Arrhythmia detector and alarm (including ST-segment measurement and alarm). (a) Identification. The arrhythmia detector and alarm device monitors an electrocardiogram and is designed to...

  3. [Arrhythmias in pregnancy. How and when to treat?].

    PubMed

    Flores, Jorge R Gómez; Márquez, Manlio F

    2007-01-01

    Cardiac arrhythmias can develop during pregnancy. The risk of arrhythmias is relatively higher during labor and delivery. Potential factors that can promote arrhythmias in pregnancy or during labor and delivery, include the direct cardiac electrophysiological effects of hormones, changes in autonomic tone, hemodynamic perturbations, hypokalemia, and underlying heart disease. In this review, the basis for treatment of supraventricular and ventricular tachycardias are described. No drug therapy is usually needed for the management of supraventricular or ventricular premature beats, but potential stimulants, such as smoking, caffeine, and alcohol should be eliminated. In paroxysmal supraventricular tachycardia, vagal stimulation maneuvers should be attempted first. In pregnant women with atrial fibrillation, the goal of treatment is conversion to sinus rhythm by electrical cardioversion. Rate control can be achieved by a cardioselective beta-adrenergic blocker drug and/ or digoxin. Ventricular arrhythmias may occur in the pregnant women, specially when cardiomyopathy, congenital heart disease, valvular heart disease, or mitral valve prolapse exists. Electrical cardioversion or treatment with sotalol may be used (amiodarone is not safe for the fetus). Finally, in women with congenital long QT syndrome, beta-blocker therapy must be continued during pregnancy and postpartum period. PMID:17972373

  4. Channelopathies - emerging trends in the management of inherited arrhythmias.

    PubMed

    Chockalingam, Priya; Mizusawa, Yuka; Wilde, Arthur Am

    2015-01-01

    In spite of their relative rarity, inheritable arrhythmias have come to the forefront as a group of potentially fatal but preventable cause of sudden cardiac death in children and (young) adults. Comprehensive management of inherited arrhythmias includes diagnosing and treating the proband and identifying and protecting affected family members. This has been made possible by the vast advances in the field of molecular biology enabling better understanding of the genetic underpinnings of some of these disease groups, namely congenital long QT syndrome, catecholaminergic polymorphic ventricular tachycardia and Brugada syndrome. The ensuing knowledge of the genotype-phenotype correlations enables us to risk-stratify, prognosticate and treat based on the genetic test results. The various diagnostic modalities currently available to us, including clinical tools and genetic technologies, have to be applied judiciously in order to promptly identify those affected and to spare the emotional burden of a potentially lethal disease in the unaffected individuals. The therapeutic armamentarium of inherited arrhythmias includes pharmacological agents, device therapies and surgical interventions. A treatment strategy keeping in mind the risk profile of the patients, the local availability of drugs and the expertise of the treating personnel is proving effective. While opportunities for research are numerous in this expanding field of medicine, there is also tremendous scope for incorporating the emerging trends in managing patients and families with inherited arrhythmias in the Indian subcontinent. PMID:25852242

  5. Diagnosis, treatment and follow up of neonatal arrhythmias

    PubMed Central

    Binnetoğlu, Fatih Köksal; Babaoğlu, Kadir; Altun, Gürkan; Türker, Gülcan

    2014-01-01

    Summary Objective This study aimed to evaluate the aetiology, spectrum, course and outcomes of neonates with arrhythmias observed in a tertiary neonatal intensive care unit from 2007 to 2012. Methods Neonates with rhythm problems were included. The results of electrocardiography (ECG), Holter ECG, echocardiography and biochemical analysis were evaluated. The long-term results of follow up were reviewed. Results Forty-five patients were male (68%) and 21 (32%) were female. Fifty-five patients (83.3%) were term, 11 (16.6%) were preterm, and 34% were diagnosed in the prenatal period. Twenty cases (30.3%) had congenital heart disease. Twenty-three patients (34.8%) were diagnosed during the foetal period. The most common arrhythmias were supraventricular ectopic beats and supraventricular tachycardia (SVT) at 39.3 and 22.7%, respectively. SVT recurred in five patients after the neonatal period. Conclusion Supraventricular ectopic beats and SVT were the most common arrhythmias during the neonatal period. Although the prognosis of arrhythmias in the neonatal period is relatively good, regular monitoring is required. PMID:24844549

  6. Infant Visual Sustained Attention and Respiratory Sinus Arrhythmia.

    ERIC Educational Resources Information Center

    Richards, John E.

    1987-01-01

    Tested the model which posits that heart-rate deceleration and respiratory sinus arrhythmia are indices of infant attention. Infants studied cross-sectionally at 14, 20, and 26 weeks of age were presented with complex patterns on a TV screen which were accompanied by an "interrupting stumulus". (Author/BN)

  7. Electrocardiographic abnormalities and cardiac arrhythmias in structural brain lesions.

    PubMed

    Katsanos, Aristeidis H; Korantzopoulos, Panagiotis; Tsivgoulis, Georgios; Kyritsis, Athanassios P; Kosmidou, Maria; Giannopoulos, Sotirios

    2013-07-31

    Cardiac arrhythmias and electrocardiographic abnormalities are frequently observed after acute cerebrovascular events. The precise mechanism that leads to the development of these arrhythmias is still uncertain, though increasing evidence suggests that it is mainly due to autonomic nervous system dysregulation. In massive brain lesions sympathetic predominance and parasympathetic withdrawal during the first 72 h are associated with the occurrence of severe secondary complications in the first week. Right insular cortex lesions are also related with sympathetic overactivation and with a higher incidence of electrocardiographic abnormalities, mostly QT prolongation, in patients with ischemic stroke. Additionally, female sex and hypokalemia are independent risk factors for severe prolongation of the QT interval which subsequently results in malignant arrhythmias and poor outcome. The prognostic value of repolarization changes commonly seen after aneurysmal subarachnoid hemorrhage, such as ST segment, T wave, and U wave abnormalities, still remains controversial. In patients with traumatic brain injury both intracranial hypertension and cerebral hypoperfusion correlate with low heart rate variability and increased mortality. Given that there are no firm guidelines for the prevention or treatment of the arrhythmias that appear after cerebral incidents this review aims to highlight important issues on this topic. Selected patients with the aforementioned risk factors could benefit from electrocardiographic monitoring, reassessment of the medications that prolong QTc interval, and administration of antiadrenergic agents. Further research is required in order to validate these assumptions and to establish specific therapeutic strategies. PMID:22809542

  8. The Wedensky test predicts malignant ventricular arrhythmias after myocardial infarction

    PubMed Central

    2013-01-01

    Objectives. Better tools are needed for detection of future malignant ventricular arrhythmias post myocardial infarct (MI). Wedensky Modulation (WM) is a new semi-invasive method: A short low-amplitude electrical impulse is applied synchronized to the QRS between a precordial and dorsal thoracic patch, and changes in the following QRS-T are registered. Design. A total of 357 (MI) ICD patients underwent WM testing. QRS-T wavelet analysis provided WM Indexes for the QRS complex (WMI-R) and T wave (WMI-T). Outcome was the time to first occurrence of appropriate device therapy for ventricular arrhythmia. Patients were followed at 6-month intervals for 2 years. Results. No arrhythmia was induced by the testing. Two-year appropriate arrhythmia treatment occurred in 35% (WMI-R positive) versus 25% (WMI-R negative, p = 0.014), and. 45% versus 26% (p = 0.001) for WMI-T positive versus negative. Two-year event rates of WMI-R or WMI-T positive versus WMI-R and WMI-T negative were 36% versus 22% (p = 0.004). In Cox proportional hazard model, the combination of WMI-R and WMI-T was the only statistically significant event predictor (p = 0.003). Conclusion. Potentially life-threatening ventricular arrhythmic events could be predicted by the WM test. In combination with other risk factors WMI may be useful in these patients. PMID:24050376

  9. Channelopathies - Emerging Trends in The Management of Inherited Arrhythmias

    PubMed Central

    Chockalingam, Priya; Mizusawa, Yuka; Wilde, Arthur A.M.

    2016-01-01

    In spite of their relative rarity, inheritable arrhythmias have come to the forefront as a group of potentially fatal but preventable cause of sudden cardiac death in children and (young) adults. Comprehensive management of inherited arrhythmias includes diagnosing and treating the proband and identifying and protecting affected family members. This has been made possible by the vast advances in the field of molecular biology enabling better understanding of the genetic underpinnings of some of these disease groups, namely congenital long QT syndrome, catecholaminergic polymorphic ventricular tachycardia and Brugada syndrome. The ensuing knowledge of the genotype-phenotype correlations enables us to risk-stratify, prognosticate and treat based on the genetic test results. The various diagnostic modalities currently available to us, including clinical tools and genetic technologies, have to be applied judiciously in order to promptly identify those affected and to spare the emotional burden of a potentially lethal disease in the unaffected individuals. The therapeutic armamentarium of inherited arrhythmias includes pharmacological agents, device therapies and surgical interventions. A treatment strategy keeping in mind the risk profile of the patients, the local availability of drugs and the expertise of the treating personnel is proving effective. While opportunities for research are numerous in this expanding field of medicine, there is also tremendous scope for incorporating the emerging trends in managing patients and families with inherited arrhythmias in the Indian subcontinent. PMID:25852242

  10. Circadian rhythms in cardiac arrhythmias and opportunities for their chronotherapy.

    PubMed

    Portaluppi, Francesco; Hermida, Ramón C

    2007-08-31

    It is now well established that nearly all functions of the body, including those that influence the pharmacokinetics and pharmacodynamics of medications, exhibit significant 24-hour variation. The electrical properties of the heart as well as cardiac arrhythmias also vary as circadian rhythms, even though the suboptimal methods initially used for their investigation slowed their identification and thorough characterization. The application of continuous Holter monitoring of the electrical properties of the heart has revealed 24-hour variation in the occurrence of ventricular premature beats with the peak in events, in diurnally active persons, between 6 a.m. and noon. After the introduction of implantable cardioverter-defibrillators, ventricular tachycardia or fibrillation were also found to peak in the same period of the day. Even defibrillator energy requirements show circadian variation, thus supporting the need for a temporal awareness in the therapeutic approach to arrhythmias. Imbalanced autonomic tone, circulating levels of catecholamines, increased heart rate and blood pressure, all established determinants of cardiac arrhythmias, show circadian variations and underlie the genesis of the circadian pattern of cardiac arrhythmias. Arrhythmogenesis appears to be suppressed during nighttime sleep, and this can influence the evaluation of the efficacy of antiarrhythmic medications in relation to their administration time. Unfortunately, very few studies have been undertaken to assess the proper timing (chronotherapy) of antiarrhythmic medications as means to maximize efficacy and possibly reduce side effects. Further research in this field is warranted and could bring new insight and clinical advantage. PMID:17659808

  11. Potentially fatal arrhythmias in two cases of adult Kawasaki disease.

    PubMed

    Watanabe, Hirofumi; Kato, Masataka; Ayusawa, Mamoru

    2016-03-01

    Fatal arrhythmias in asymptomatic Kawasaki disease patients with normal left ventricular function have rarely been reported. In this study, we report the cases of two adult patients with largely unpredictable sudden cardiac arrest, despite almost-normal left ventricular function even after the diagnosis of presumed Kawasaki disease, as well as consider the mechanisms involved with reference to the literature. PMID:26424562

  12. Fetal cardiac arrhythmia detection and in utero therapy

    PubMed Central

    Strasburger, Janette F.; Wakai, Ronald T.

    2010-01-01

    The human fetal heart develops arrhythmias and conduction disturbances in response to ischemia, inflammation, electrolyte disturbances, altered load states, structural defects, inherited genetic conditions, and many other causes. Yet sinus rhythm is present without altered rate or rhythm in some of the most serious electrophysiological diseases, which makes detection of diseases of the fetal conduction system challenging in the absence of magnetocardiographic or electrocardiographic recording techniques. Life-threatening changes in QRS or QT intervals can be completely unrecognized if heart rate is the only feature to be altered. For many fetal arrhythmias, echocardiography alone can assess important clinical parameters for diagnosis. Appropriate treatment of the fetus requires awareness of arrhythmia characteristics, mechanisms, and potential associations. Criteria to define fetal bradycardia specific to gestational age are now available and may allow detection of ion channelopathies, which are associated with fetal and neonatal bradycardia. Ectopic beats, once thought to be entirely benign, are now recognized to have important pathologic associations. Fetal tachyarrhythmias can now be defined precisely for mechanism-specific therapy and for subsequent monitoring of response. This article reviews the current and future diagnostic techniques and pharmacologic treatments for fetal arrhythmia. PMID:20418904

  13. Arrhythmias and Electrocardiographic Changes in Systolic Heart Failure

    PubMed Central

    Devkota, Ashok; Bakhit, Ahmed; Dufresne, Alix; Oo, Aung Naing; Parajuli, Premraj; Manhas, Saveena

    2016-01-01

    Background: Heart failure is a common condition that that leads to hospitalization. It is associated with various atrial and ventricular arrhythmias. Aim: The aim of this study is to find common arrhythmias and electrocardiographic changes in hospitalized patients who have systolic heart failure. Materials and Methods: This is a retrospective study of medical records, and electrocardiograms (EKGs) of 157 patients admitted to our hospital who had systolic heart failure with ejection fraction (EF) <50% on echocardiogram. Based on EF, the patients were divided into two groups; one with EF ≤ 35% and the other with EF > 35%. Twelve-lead EKG of these patients was studied to identify common arrhythmia and demographic variables; laboratory results were compared to identify the differences. Results: A total of 157 patients with systolic heart failure, 63.7% had an EF ≤ 35%. Hypertension 82.8%, diabetes 49%, coronary artery disease 40.8%, chronic obstructive pulmonary disease or bronchial asthma 22.3%, and stroke 12.1% were common associated co-morbidities. On analysis of EKG, 28.6% had tachycardia, 21.9% had prolonged PR > 200 ms, 16.3% had wide QRS > 120 ms, 70.7% had prolonged corrected QT (QTc), and 42.2% had left axis deviation. The most common arrhythmias were sinus tachycardia and atrial fibrillation/flutter which were found in 14.6% and 13.4%, respectively. The left ventricular hypertrophy was a common abnormality found in 22.4% followed by ventricular premature contractions 18.4%, atrial premature contractions 9.5%, and left bundle branch block 6.1%. Patients with severe systolic heart failure had prolonged QRS (P = 0.02) and prolonged QTc (P = 0.01) as compared to the other group. Conclusions: Sinus tachycardia and atrial fibrillation/flutter were common arrhythmias in patients with systolic heart failure. Patients with severe systolic heart failure had statistically significant prolongation of the QRS duration and QTc interval. PMID:27213140

  14. Antiarrhythmic actions of verapamil against ischaemic arrhythmias in the rat.

    PubMed Central

    Curtis, M. J.; MacLeod, B. A.; Walker, M. J.

    1984-01-01

    The actions of intravenous verapamil against arrhythmias induced by occlusion of a coronary artery were investigated in conscious rats. Verapamil (2-20 mg kg-1, i.v. given pre-occlusion) dose-dependently reduced arrhythmias in rats with either large or small occluded zones at an ED50 of 6 mg kg-1. This dose was effective when given immediately post-occlusion. Severe arrhythmias, as opposed to PVC, were preferentially reduced. In conscious, and pentobarbitone-anaesthetized rats, verapamil (6 mg kg-1) had different effects on electrically-induced arrhythmias, and the ECG, from an equi-effective anti-arrhythmic dose of quinidine (20 mg kg-1, i.v.). Quinidine decreased following frequency, but increased threshold current and pulse width, whereas verapamil did not. Both drugs increased P-R interval, but only quinidine increased QRS and Q-T intervals. Thirty minutes post-occlusion, the verapamil content of tissue and blood was determined after a 6 mg kg-1 dose given pre- or post-occlusion. Measurable levels of verapamil were found in both normal and ischaemic myocardium. Plasma and plasma water concentrations were 3.6 +/- 0.8 mumol l-1 and 0.6 +/- 0.1 mumol l-1 (mean +/- s.e. mean), respectively following post-occlusion administration vs. 2.7 +/- 1.2 and 0.24 +/- 0.04 for pre-occlusion administration. Plasma water concentrations were close to IC50 values for inhibition of contractility in rat atria and ventricles. Similar concentrations depressed slow action potentials induced in rat ventricles by raised K+ We suggest that the ability of verapamil to prevent severe ventricular arrhythmias following myocardial ischaemia in the conscious rat is largely due to the calcium antagonist effects of the drug. PMID:6487902

  15. Atrial Arrhythmias in Astronauts - Summary of a NASA Summit

    NASA Technical Reports Server (NTRS)

    Barr, Yael R.; Watkins, Sharmila D.; Polk, J. D.

    2010-01-01

    Background and Problem Definition: To evaluate NASA s current standards and practices related to atrial arrhythmias in astronauts, Space Medicine s Advanced Projects Section at the Johnson Space Center was tasked with organizing a summit to discuss the approach to atrial arrhythmias in the astronaut cohort. Since 1959, 11 cases of atrial fibrillation, atrial flutter, or supraventricular tachycardia have been recorded among active corps crewmembers. Most of the cases were paroxysmal, although a few were sustained. While most of the affected crewmembers were asymptomatic, those slated for long-duration space flight underwent radiofrequency ablation treatment to prevent further episodes of the arrhythmia. The summit was convened to solicit expert opinion on screening, diagnosis, and treatment options, to identify gaps in knowledge, and to propose relevant research initiatives. Summit Meeting Objectives: The Atrial Arrhythmia Summit brought together a panel of six cardiologists, including nationally and internationally renowned leaders in cardiac electrophysiology, exercise physiology, and space flight cardiovascular physiology. The primary objectives of the summit discussions were to evaluate cases of atrial arrhythmia in the astronaut population, to understand the factors that may predispose an individual to this condition, to understand NASA s current capabilities for screening, diagnosis, and treatment, to discuss the risks associated with treatment of crewmembers assigned to long-duration missions or extravehicular activities, and to discuss recommendations for prevention or management of future cases. Summary of Recommendations: The summit panel s recommendations were grouped into seven categories: Epidemiology, Screening, Standards and Selection, Treatment of Atrial Fibrillation Manifesting Preflight, Atrial Fibrillation during Flight, Prevention of Atrial Fibrillation, and Future Research

  16. A 5.8S nuclear ribosomal RNA gene sequence database: applications to ecology and evolution

    NASA Technical Reports Server (NTRS)

    Cullings, K. W.; Vogler, D. R.

    1998-01-01

    We complied a 5.8S nuclear ribosomal gene sequence database for animals, plants, and fungi using both newly generated and GenBank sequences. We demonstrate the utility of this database as an internal check to determine whether the target organism and not a contaminant has been sequenced, as a diagnostic tool for ecologists and evolutionary biologists to determine the placement of asexual fungi within larger taxonomic groups, and as a tool to help identify fungi that form ectomycorrhizae.

  17. Measuring the economic value of alternative clam fishing management practices in the Venice Lagoon: results from a conjoint valuation application

    NASA Astrophysics Data System (ADS)

    Nunes, Paulo A. L. D.; Rossetto, Luca; de Blaeij, Arianne

    2004-11-01

    This article focuses on the economic valuation of alternative clam management practices in the Venice Lagoon. The proposed valuation method is characterized by the design of a survey questionnaire applied to the fishermen population. In each questionnaire, two fishing alternatives are described. The respondent is asked to choose one of them. This valuation method, referred in the article as conjoint valuation, gives sufficient flexibility to set, alter, and combine the valuation of different clam management practices. Furthermore, this approach presents an important advantage to the well-known contingent valuation method since it makes the monetary valuation of each management attribute possible. Estimation results show that all three attributes used in the questionnaire to describe and value different clam management practices—price of the annual permit and fishing technological system—are statistically robust, indicating that fishermen bear a utility change whenever these attributes change. In particular, fishermen's willingness to pay for a larger clam fishing area ranges between 568 and 811 € per year. In addition, an individual's willingness to pay for a fishing practice exclusively based on the vibrant rake system ranges between 1005 and 2456 €. Finally, the adoption of a clam fish management practice in the Venice Lagoon that is exclusively based on the use of manual rakes, which is associated with the lowest damage to the lagoon ecosystem, will represent a welfare loss of 5904 € per fisherman per year. Combining such a value estimate with the total number of fishermen currently operating in the Lagoon of Venice, the welfare loss associated with the adoption of this type of clam management policy amounts to 11.8 € million per year. This figure can be regarded as an upper bound to the cost of implementation of a clam fishing system anchored in the use of manual, ecosystem friendly rakes.

  18. The land subsidence of the Venice historical center: twenty years of monitoring by SAR-based interferometry

    NASA Astrophysics Data System (ADS)

    Tosi, L.; Strozzi, T.; Teatini, P.

    2012-12-01

    The subsidence of Venice, one of the most beautiful and famous cities in the world, is well known not by reason of the magnitude of the ground movement, which amounts to less than 15 cm over the last century, but because it has seriously compromised the ground safety level of the city in relation of its small elevation above the sea. The lowering of Venice is still today a subject of debates with large rumours on press releases every time a scientific paper is published on the topic. Over the last two decades, satellites instrumented with SAR sensors provided excellent data for detecting land displacements by inteferometric processing. In particular, the accuracy achieved by Persistent Scatterer Interferometry (PSI) and the impressive number of detected measurement points have progressively reduced the use of in situ traditional measurements, i.e. leveling survey, for monitoring land displacements of Venice. In fact, the intensive urban development makes the historical center an optimal site for PSI. On the other hand, the correct interpretation of the PSI outcomes, which provide the relative movement of single churches, palaces, bridges with millimetric precision and metric spatial resolution, require a deep knowledge of the city and its subsoil due to the peculiarity of this urban area developed over the centuries within the sea. We investigate the movements of Venice by Interferometric Point Target Analysis (IPTA) over the last 20 years using SAR acquisitions of the ERS-1/2, ENVISAT, TerraSAR-X, and Cosmo-SkyMed satellites. The density of detected scatterers is one order of magnitude larger with the newest very high resolution X-band sensors from TerraSAR-X and Cosmo-SkyMed, but by reason of the larger observation period the accuracy of the mean displacement rate of the C-band ERS and ENVISAT is higher. IPTA results have been calibrated using leveling and permanent GPS stations to correct the so-called flattening problem, i.e. the slight phase tilt resulting by

  19. Remote sensing retrieval of water constituents in shallow coastal waters with applications to the Venice lagoon

    NASA Astrophysics Data System (ADS)

    Zhou, X.; Marani, M.; Albertson, J. D.; Silvestri, S.

    2013-12-01

    Lagoons and estuaries worldwide are experiencing accelerated ecosystem degradation due to increased direct and indirect anthropogenic pressure. Monitoring the environmental state and trends in such environment would benefit from the use of remote sensing techniques, which can access a wide range of spatial and temporal scales. However, most remote sensors are not suitable for monitoring shallow and optically-complex waters, because of their low spatial and spectral-resolution and of the uncertainties associated with the contribution of the bottom sediment to the observed remote sensing signal. We apply here a remote sensing-based approach to mapping suspended sediment and chlorophyll concentrations in the shallow Venice lagoon, which integrates hyperspectral remote sensing data, a simplified radiative transfer model, and in-situ water quality measurements. First, we calibrate and validate the key parameters of the model, such as bottom albedo and absorption/backscattering coefficients of sediment, by comparing remote sensing derived water constituent concentrations with in-situ data. We then determine the statistics of those parameters, and the associated estimation uncertainty, by applying a bootstrapping technique. Finally, the lagoon-wide distribution of water constituent concentrations, and of the estimation uncertainty, is derived by inverting the model. The estimates are consistent with measured concentrations and their known optical properties, particularly for the suspended sediment concentrations, while chlorophyll concentration estimates remain more uncertain. Our analyses show that remote sensing methods can provide reliable water constituent concentrations at the system scale and that uncertainties become overwhelming only in particularly shallow areas (water depths indicatively lower than 1 m in the present application). Importantly, the joint use of radiative transfer models, in situ observations, and statistical techniques allows the production of

  20. The mechanistic basis for psoriasis immunopathogenesis: translating genotype to phenotype. Report of a workshop, Venice, 2012.

    PubMed

    Bachelez, H; Viguier, M; Tebbey, P W; Lowes, M; Suárez-Fariñas, M; Costanzo, A; Nestle, F O

    2013-08-01

    The International Psoriasis Council, a global nonprofit organization dedicated to advancing psoriasis research and treatment, led an initiative to better define the pathogenic mechanisms that constitute psoriasis. In September 2012, a workshop was held at the 42nd Annual European Society for Dermatological Research in Venice, Italy. By assembling a panel of global dermatology and immunology experts, the objective was to evaluate the current status of the science explaining the mechanism of disease in psoriasis, e.g. dysregulation of the skin immune system and perturbations of epidermal homeostasis. The workshop consisted of four oral presentations, which addressed key topics in psoriasis, delivered by Hervé Bachelez (Paris, France), Antonio Costanzo (Rome, Italy), Michelle Lowes (New York, NY, U.S.A.) and Frank Nestle (London, U.K.). A global expert panel was assembled to stimulate dialogue and debate: Kevin Cooper (Cleveland, OH, U.S.A.), Michel Gilliet (Lausanne, Switzerland), Joerg Prinz (Munich, Germany), Martin Röcken (Tubingen, Germany), Jens Schroeder (Kiel, Germany), Manuelle Viguier (Paris, France), Mayte Suárez-Fariñas (New York, NY, U.S.A.) and Cristina Zielinski (Berlin, Germany). Collectively, the presentations demonstrated the significant advances in understanding immune regulation that have occurred over the past decade by virtue of the study of psoriasis subtypes, phenotypic manifestations and genetic associations. Elucidating the pathogenic and genetic basis of psoriasis holds the promise of a complete understanding of disease mechanisms, predictors of treatment response, novel drug development strategies and customized therapeutic regimens for the individual patient. PMID:23941252

  1. Historical changes in the structure and functioning of the benthic community in the lagoon of Venice

    NASA Astrophysics Data System (ADS)

    Pranovi, Fabio; Da Ponte, Filippo; Torricelli, Patrizia

    2008-03-01

    One of the main challenges in environmental management is how to manage the dynamics of natural environments. In this context, having information about historical changes of the structure of the biological communities could represent a useful tool to improve management strategies, contributing to refine the policy objectives, since it gives reference states with which to compare the present. The Venice lagoon represents an interesting case study, since it is a highly dynamic, but sensitive, environment which requires the adoption of prudent management. In its recent history the lagoon ecosystem has been exposed to different kinds of disturbance, from the discharge of pollutants and nutrients, to the invasion of alien species and the exploitation of its biological resources by using highly impacting fishing gears. The analysis of available data about the macro-benthic community, from 1935 to 2004, allows the description of changes of the community structure over almost 70 years, showing a sharp decrease in its diversity. In order to obtain information about its functioning, it is necessary to know how these changes have affected processes at the community and system level. In shallow water ecosystems, as the control is mainly due to the benthic compartment, variations in the structure of the benthic community can induce modifications in processes at different hierarchical levels. The trophic structure analysis has revealed major changes during the period; from a well-assorted structure in 1935, to an herbivore-detritivore dominated one in the 1990s, and finally to a filter feeder dominated structure during the last decade. This has produced variations in the secondary production and it has induced modifications in the type of the ecosystem control. These changes are discussed in the light of the dynamics of the main driving forces.

  2. Understanding relationships between morphology and ecosystem structure in a shallow tidal basins of Venice lagoon

    NASA Astrophysics Data System (ADS)

    Giuseppina Persichillo, Maria; Taramelli, Andrea; Valentini, Emiliana; Filipponi, Federico; Meisina, Claudia; Zucca, Francesco

    2014-05-01

    Coastal wetlands represent complex ecosystems prone to continue fluctuation of their internal equilibrium. They are valuable natural resources characterized by the continue interactions between geomorphological and biological components. Their adaptation to changing conditions is highly dependent on the rate and extent of spatial and temporal processes and their responses are still poorly understood. According to this, the vulnerability assessment to natural and human made hazard have became fundamental to analyse the resilience of these areas, their ability to cope with the impacts from externally driven forces or the efforts needed to minimize the impacts (Gitay et al., 2011). The objective of this research is to develop a comprehensive and replicable method through the application of Multi-Source data analysis, based on the integration of Earth Observation data and field survey, to analyse a shallow tidal basin of salt marshes, located in the northern part of the Venice lagoon. The study site is characterised by relatively elevated areas colonized by halophytic vegetation, and tidal flats, with not vegetated areas, characterized by lower elevations. Sub-pixel processing techniques (Spectral Mixing Analysis - SMA) were used to analyse the spatial distribution of both vegetation and sediments typology. Furthermore the classifications were assayed in terms of spatial (Power law) and temporal (Empirical Orthogonal Functions) patterns, in order to find the main characteristics of the aforementioned spatial trends and their variation over time. The principal aim is to study the spatio-temporal evolution of this coastal wetland area, in order to indentify tipping points, namely thresholds, beyond which the system reaches critical state and the main climatic, hydrodynamic and morphological variables that may influence and increase this behaviour. This research represents a new approach to study the geomorphological processes and to improve the management and

  3. Build your own cogeneration plant. [Santa Clara, Ca 5. 8-MW plant

    SciTech Connect

    Von Raesfeld, D.

    1981-11-01

    Santa Clara, California's new municipal cogeneration plant generates 5.8 MW of power for the utility and 38,000 pounds of steam per hour for a papermaking firm. A third gas-fired combustion turbine generator can be added to the original two to boost plant output. Santa Clara undertook the one-year construction project to increase its non-renewable fuel efficiency and save fuel costs. The city manager outlines Santa Clara's planning for the projects and the benefits the city will experience from its aggressive pursuit of cogeneration. 1 figure. (DCK)

  4. Measurement of sputtered efflux from 5-, 8-, and 30-cm diameter mercury ion thrusters

    NASA Technical Reports Server (NTRS)

    Weigand, A. J.; Mirtich, M. J.

    1975-01-01

    A study was undertaken to investigate the sputtered efflux from 5-, 8-, and 30-cm diameter mercury ion thrusters. Quartz crystal microbalances and fused silica samples were used to analyze the sputtered flux. Spectral transmittance measurements and spectrographic analysis of the samples were made after they were exposed to different thruster effluence by operating the thrusters at various conditions and durations of time. These measurements were used to locate the source of the efflux and determine its accumulated effect at various locations near the thruster. Comparisons of in situ and ex situ transmittance measurements of samples exposed to thruster efflux are also presented.

  5. Development of a remote handheld cardiac arrhythmia monitor.

    PubMed

    Singh, Swaroop S; Hsiao, Henry S

    2006-01-01

    In this paper we present the design and development of a real-time remote handheld cardiac arrhythmic monitoring system (RCAM). A client-server model based on Internet protocols was used. ECG data was transmitted from the remote handheld client to a centralized server, where the QRS and premature ventricular contraction detection algorithms were implemented and graded depending on the number and pattern of PVCs present. The QRS sensitivity and specificity on ECG records from Physionet archives in absence of arrhythmia was 100% and 99.62%, while in presence of arrhythmia was 99.34% and 99.31%. The average 'negative time' measured on ventricular tachyarrhythmia records was 92 seconds. The RCAM can provide remote detection of cardiac abnormalities and give specific diagnosis and recommendations of actions to be taken immediately. The limitation due to the inability of the PDA to perform complex computations was overcome by the use of the remote server. PMID:17947043

  6. ECG Signal Analysis and Arrhythmia Detection using Wavelet Transform

    NASA Astrophysics Data System (ADS)

    Kaur, Inderbir; Rajni, Rajni; Marwaha, Anupma

    2016-06-01

    Electrocardiogram (ECG) is used to record the electrical activity of the heart. The ECG signal being non-stationary in nature, makes the analysis and interpretation of the signal very difficult. Hence accurate analysis of ECG signal with a powerful tool like discrete wavelet transform (DWT) becomes imperative. In this paper, ECG signal is denoised to remove the artifacts and analyzed using Wavelet Transform to detect the QRS complex and arrhythmia. This work is implemented in MATLAB software for MIT/BIH Arrhythmia database and yields the sensitivity of 99.85 %, positive predictivity of 99.92 % and detection error rate of 0.221 % with wavelet transform. It is also inferred that DWT outperforms principle component analysis technique in detection of ECG signal.

  7. Multiple cardiac arrhythmia recognition using adaptive wavelet network.

    PubMed

    Lin, Chia-Hung; Chen, Pei-Jarn; Chen, Yung-Fu; Lee, You-Yun; Chen, Tainsong

    2005-01-01

    This paper proposes a method for electrocardiogram (ECG) heartbeat pattern recognition using adaptive wavelet network (AWN). The ECG beat recognition can be divided into a sequence of stages, starting from feature extraction and conversion of QRS complexes, and then identifying cardiac arrhythmias based on the detected features. The discrimination method of ECG beats is a two-subnetwork architecture, consisting of a wavelet layer and a probabilistic neural network (PNN). Morlet wavelets are used to extract the features from each heartbeat, and then PNN is used to analyze the meaningful features and perform discrimination tasks. The AWN is suitable for application in a dynamic environment, with add-in and delete-off features using automatic target adjustment and parameter tuning. The experimental results obtained by testing the data of the MIT-BIH arrhythmia database demonstrate the efficiency of the proposed method. PMID:17281539

  8. Classification enhancible grey relational analysis for cardiac arrhythmias discrimination.

    PubMed

    Lin, Chia-Hung

    2006-04-01

    This paper proposes a method for electrocardiogram (ECG) heartbeat recognition using classification enhancible grey relational analysis (GRA). The ECG beat recognition can be divided into a sequence of stages, starting with feature extraction and then according to characteristics to identify the cardiac arrhythmias including the supraventricular ectopic beat, bundle branch ectopic beat, and ventricular ectopic beat. Gaussian wavelets are used to enhance the features from each heartbeat, and GRA performs the recognition tasks. With the MIT-BIH arrhythmia database, the experimental results demonstrate the efficiency of the proposed non-invasive method. Compared with artificial neural network, the test results also show high accuracy, good adaptability, and faster processing time for the detection of heartbeat signals. PMID:16937172

  9. Cryotherapy of cardiac arrhythmia: From basic science to the bedside.

    PubMed

    Avitall, Boaz; Kalinski, Arthur

    2015-10-01

    This review focuses on the basic science of cellular destruction by tissue freezing and application of transvenous cryocatheter technology to treat cardiac arrhythmia. Ideally, foci for arrhythmias are selectively ablated, arrhythmogenic tissues are destroyed, and reentry circuits are bisected in order to silence adverse electrical activity, with the goal of restoring normal sinus rhythm. The mechanism of ablation using cryotherapy results in distinct lesion qualities advantageous to radiofrequency (Khairy P, Chauvet M, Lehman J, et al. Lower incidence of thrombus formation with cryoenergy versus radiofrequency catheter ablation. Circulation 2003;107:2045-2050). This review is devoted to the mechanism of cryoablation, postablation histopathological changes, and how this information should be used by the clinicians to improve safety and maximize ablation success. PMID:26031374

  10. Biomarkers in electrophysiology: role in arrhythmias and resynchronization therapy

    PubMed Central

    Bose, Abhishek; Truong, Quynh A.

    2015-01-01

    Circulating biomarkers related to inflammation, neurohormones, myocardial stress, and necrosis have been associated with commonly encountered arrhythmic disorders such as atrial fibrillation (AF) and more malignant processes including ventricular arrhythmias (VA) and sudden cardiac death (SCD). Both direct and indirect biomarkers implicated in the heart failure cascade have potential prognostic value in patients undergoing cardiac resynchronization therapy (CRT). This review will focus on the role of biomarkers in AF, history of SCD, and CRT with an emphasis to improve clinical risk assessment for arrhythmias and patient selection for device therapy. Notably, information obtained from biomarkers may supplement traditional diagnostic and imaging techniques, thus providing an additional benefit in the management of patients. PMID:25715916

  11. REM sleep-related brady-arrhythmia syndrome.

    PubMed

    Janssens, Wim; Willems, Rik; Pevernagie, Dirk; Buyse, Bertien

    2007-09-01

    Rapid eye movement (REM) sleep-related brady-arrhythmia syndrome is a cardiac rhythm disorder characterised by asystoles lasting several seconds during REM sleep in otherwise healthy individuals. In contrast to arrhythmias associated with obstructive sleep apnea, REM sleep-related sinus arrests and atrioventricular (AV) blocks are not associated with episodes of apnea or hypopnea. In literature, only few cases have been published, suggesting that the prevalence of this nighttime rhythm disorder is very rare. In this paper, we report two new cases of REM sleep-related sinus arrests and one case of REM sleep-related total AV block. To explore the underlying mechanism, an analysis of heart rate variability was performed. In a matched control population, we observed a significant lower low-to-high frequency (LF/HF) ratio in slow wave sleep as compared to REM sleep (2.04 +/- 1.2 vs 4.55 +/- 1.82, respectively [Mann-Whitney U test p < 0.01]), demonstrating a global increase in sympathetic activity during REM. When using the same technique in two of three patients with REM-related arrhythmias, the shift to an increased LF/HF ratio from slow wave sleep to REM sleep tended to be lower. This may reflect an increased vagal activity (HF component) during REM sleep in these subjects. We, therefore, hypothesise that, in our patients with REM sleep-related arrhythmias, the overall dominance of sympathetic activity during REM is present but to a lesser extent and temporarily switches into vagal dominance when the bursts of REMs occur. As it was still unclear whether these REM sleep-related asystoles needed to be paced, we compared our treatment and these of previously reported cases with the current American College of Cardiology/American Heart Association guidelines for implantation of cardiac pacemakers. PMID:17375344

  12. Feature-based MRI data fusion for cardiac arrhythmia studies.

    PubMed

    Magtibay, Karl; Beheshti, Mohammadali; Foomany, Farbod Hosseyndoust; Massé, Stéphane; Lai, Patrick F H; Zamiri, Nima; Asta, John; Nanthakumar, Kumaraswamy; Jaffray, David; Krishnan, Sridhar; Umapathy, Karthikeyan

    2016-05-01

    Current practices in studying cardiac arrhythmias primarily use electrical or optical surface recordings of a heart, spatially limited transmural recordings, and mathematical models. However, given that such arrhythmias occur on a 3D myocardial tissue, information obtained from such practices lack in dimension, completeness, and are sometimes prone to oversimplification. The combination of complementary Magnetic-Resonance Imaging (MRI)-based techniques such as Current Density Imaging (CDI) and Diffusion Tensor Imaging (DTI) could provide more depth to current practices in assessing the cardiac arrhythmia dynamics in entire cross sections of myocardium. In this work, we present an approach utilizing feature-based data fusion methods to demonstrate that complimentary information obtained from electrical current distribution and structural properties within a heart could be quantified and enhanced. Twelve (12) pairs of CDI and DTI image data sets were gathered from porcine hearts perfused through a Langendorff setup. Images were fused together using feature-based data fusion techniques such as Joint Independent Component Analysis (jICA), Canonical Correlation Analysis (CCA), and their combination (CCA+jICA). The results suggest that the complimentary information of cardiac states from CDI and DTI are enhanced and are better classified with the use of data fusion methods. For each data set, an increase in mean correlations of fused images were observed with 38% increase from CCA+jICA compared to the original images while mean mutual information of the fused images from jICA and CCA+jICA increased by approximately three-fold. We conclude that MRI-based techniques present potential viable tools in furthering studies for cardiac arrhythmias especially Ventricular Fibrillation. PMID:26970857

  13. Exercise and Arrhythmias: A Double-Edged Sword.

    PubMed

    Manolis, Antonis S; Manolis, Antonis A

    2016-07-01

    Ample evidence indicates that moderate regular exercise is beneficial for both normal individuals and patients with cardiovascular (CV) disease. However, intense and strenuous exercise in individuals with evident or occult underlying CV abnormalities may have adverse effects with provocation and exacerbation of arrhythmias that may lead to life-threatening situations. Both of these aspects of exercise-induced effects are herein reviewed. PMID:27120033

  14. Treatment of depression in an adolescent with cardiomyopathy and arrhythmia.

    PubMed

    Tanidir, Canan; Tanidir, Ibrahim C; Tuzcu, Volkan

    2015-10-01

    Patients with cardiomyopathy have a higher incidence of mood and anxiety disorders, resulting in greater probability for hospitalisation and increased risk for arrhythmia and death. We report a case of a 16-year-old boy with Danon disease, Wolff-Parkinson-White syndrome, and hypertrophic cardiomyopathy, who later developed depression and significant weight loss. The patient was successfully treated for his anxiety and depression with mirtazapine without any adverse cardiac effects. PMID:25400066

  15. The EINTHOVEN system: toward an improved cardiac arrhythmia monitor.

    PubMed Central

    Widman, L. E.

    1991-01-01

    Contemporary cardiac arrhythmia monitors, used commonly in intensive care settings, are highly sensitive to artifact, resulting in high false alarm rates, inability to detect P waves reliably, and crude rhythm interpretation. We report on two new approaches that address these problems: a noise preprocessor that characterizes the type and degree of artifact in an ECG, and a model-based rhythm interpretation algorithm. PMID:1807639

  16. Endogenous chemical mediators of ventricular arrhythmias in ischaemic heart disease.

    PubMed

    Curtis, M J; Pugsley, M K; Walker, M J

    1993-05-01

    The causes of ventricular arrhythmias in the acute setting of coronary artery disease (myocardial ischaemia and reperfusion) may be approached using two paradigms. One, the electrophysiological paradigm (disturbance of ionic homeostasis, electrogenesis, and conduction) has not been addressed in detail here. Instead, we have focused on the concept of a chemical paradigm of arrhythmogenesis. Many endogenous chemical substances (derived from the myocardium, nerves, blood plasma, platelets, leucocytes, and endothelium) accumulate in the ischaemic tissue or are produced during reperfusion and many of these have been suggested to modulate ventricular arrhythmias. Some substances may be arrhythmogenic and others may be antiarrhythmic. Together they determine whether or not arrhythmias occur. Potentially arrhythmogenic substances include potassium, catecholamines, cAMP, histamine, 5-HT, lysophosphatidylcholine, palmitylcarnitine, platelet activating factor, prostaglandins, leukotrienes, thromboxane A2, angiotensin II, endothelin, opioids, protons, calcium, and free radicals. We have considered each of these, with the objective of evaluating which are important in arrhythmogenesis in acute ischaemia and reperfusion. Two alternative models of arrhythmogenesis are possible in the context of the chemical paradigm: a series model (where one substance or its effects determines the arrhythmogenicity of another) and a parallel model (where numerous substances operate independently to cause ventricular arrhythmias). It is not yet clear which model is most appropriate; a combination of the two is possible, so a working prototype has been constructed which accommodates both. A set of criteria (hitherto lacking) for establishing whether a substance is sufficient and necessary for arrhythmogenesis is proposed. Some generalisations are given on approaches to establishment of these criteria for putative arrhythmogenic substances. Finally, we have considered how arrhythmogenic drug

  17. Carbon monoxide exposure of subjects with documented cardiac arrhythmias

    SciTech Connect

    Chaitman, B.R.; Dahms, T.E.; Byers, S.; Carroll, L.W.; Younis, L.T.; Wiens, R.D. )

    1992-09-01

    The impact of low-level carbon monoxide exposure on ventricular arrhythmia frequency in patients with ischemic heart disease has not been thoroughly studied. The issue is of concern because of the potential proarrhythmic effect of carbon monoxide in patients with ischemic heart disease. We studied 30 subjects with well-documented coronary artery disease who had an average of at least 30 ventricular ectopic beats per hour over a 20-hour monitoring interval. By using appropriate inclusion and exclusion criteria, subjects were selected and enrolled in a randomized double-blind study to determine the effects of carbon monoxide exposure on ventricular arrhythmia frequency at rest, during exercise, and during ambulatory activities. The carbon monoxide exposure was designed to result in 3% or 5% carboxyhemoglobin levels, as measured by gas chromatography. The carbon monoxide exposure protocol produced target levels in 60 minutes, and the levels were maintained for an additional 90 minutes to provide adequate time to assess the impact of carbon monoxide on the frequency of ventricular ectopic beats. The data on total and repetitive ventricular arrhythmias were analyzed for seven specific time intervals: (1) two hours before carbon monoxide exposure; (2) during the two-hour carbon monoxide or air exposure; (3) during a two-hour rest period; (4) during an exercise period; (5) during an exercise recovery period; (6) six hours after carbon monoxide or air exposure; and (7) approximately 10 hours after exposure, or the remaining recording interval on the Holter monitor. There was no increase in ventricular arrhythmia frequency after carbon monoxide exposure, regardless of the level of carboxyhemoglobin or the type of activity.

  18. Statistical Versus Individual Forecasting Of Life-Threatening Cardiac Arrhythmias

    NASA Astrophysics Data System (ADS)

    Wessel, Niels; Meyerfeldt, Udo; Ziehmann, Christine; Schirdewan, Alexander; Kurths, Jürgen

    2002-07-01

    Ventricular tachycardia or fibrillation (VT) as fatal cardiac arrhythmias are the main factors triggering sudden cardiac death. The objective of this investigation is to find early signs of sustained VT in patients with an implanted cardioverter-defibrillator (ICD). These devices are able to safeguard patients by returning their hearts to a normal rhythm via strong defibrillatory shocks; additionally, they are able to store at least 1000 beat-to-beat intervals immediately before the onset of a life-threatening arrhythmia. We study these 1000 beat-to-beat intervals of 63 chronic heart failure ICD patients before the onset of a life-threatening arrhythmia and at a control time, i.e. without VT event. To characterize these rather short data sets, we calculate heart rate variability (HRV) parameters from time and frequency domain, from symbolic dynamics as well as the finite-time growth rates. We find that no linear parameter shows significant differences in HRV between the VT and the control time series. However, the nonlinear parameters detected a significant increase in short phases with low variability before the onset of VT (p<0.05, for time series with less than 10% ectopy). Finally, we are investigating whether these results may lead to individual predictions of VT.

  19. Ventricular arrhythmias and the His-Purkinje system.

    PubMed

    Haissaguerre, Michel; Vigmond, Edward; Stuyvers, Bruno; Hocini, Meleze; Bernus, Olivier

    2016-03-01

    Ventricular arrhythmias are a major cause of sudden death, which accounts for approximately half of cardiac mortality. The His-Purkinje system is composed of specialized cells responsible for the synchronous activation of the ventricles. However, experimental studies show that the Purkinje system can be arrhythmogenic during electrolyte imbalance, after exposure to various drugs, and in myocardial ischaemia, during which Purkinje cells can survive in anaerobic conditions. Purkinje cells can generate both automatic and triggered focal rhythms, and their network configuration can accommodate re-entrant circuits. In humans, a variety of monomorphic ventricular tachycardias can be sustained within the architecture of the Purkinje branches. Furthermore, discrete Purkinje sources can serve as critical triggers of ventricular fibrillation in a wide spectrum of patients with structural heart disease or with an apparently normal heart. In drug-resistant cases of monomorphic and polymorphic Purkinje-related ventricular tachycardias, catheter ablation is a very effective treatment. The specific transcriptional signatures and functional properties of Purkinje cells, including their intracellular calcium dynamics, underlie their extreme arrhythmogenicity. However, the identification of vulnerable individuals remains challenging, and the molecular mechanisms of Purkinje-related arrhythmias have to be characterized further to enable the development of interventions to prevent lethal cardiac arrhythmias. PMID:26727298

  20. Ventricular repolarization markers for predicting malignant arrhythmias in clinical practice

    PubMed Central

    Castro-Torres, Yaniel; Carmona-Puerta, Raimundo; Katholi, Richard E

    2015-01-01

    Malignant cardiac arrhythmias which result in sudden cardiac death may be present in individuals apparently healthy or be associated with other medical conditions. The way to predict their appearance represents a challenge for the medical community due to the tragic outcomes in most cases. In the last two decades some ventricular repolarization (VR) markers have been found to be useful to predict malignant cardiac arrhythmias in several clinical conditions. The corrected QT, QT dispersion, Tpeak-Tend, Tpeak-Tend dispersion and Tp-e/QT have been studied and implemented in clinical practice for this purpose. These markers are obtained from 12 lead surface electrocardiogram. In this review we discuss how these markers have demonstrated to be effective to predict malignant arrhythmias in medical conditions such as long and short QT syndromes, Brugada syndrome, early repolarization syndrome, acute myocardial ischemia, heart failure, hypertension, diabetes mellitus, obesity and highly trained athletes. Also the main pathophysiological mechanisms that explain the arrhythmogenic predisposition in these diseases and the basis for the VR markers are discussed. However, the same results have not been found in all conditions. Further studies are needed to reach a global consensus in order to incorporate these VR parameters in risk stratification of these patients. PMID:26301231

  1. Pattern of arrhythmias among Nigerians with congestive heart failure

    PubMed Central

    Ajayi, Olufemi E; Abiodun, Olugbenga O; Akintomide, Anthony O; Adebayo, Rasaaq A; Ogunyemi, Suraj A; Balogun, Michael O; Bamikole, Olaniyi J; Ajibare, Adeola O; Ajayi, Adesuyi A

    2015-01-01

    Background In patients with heart failure, death is often sudden due to life-threatening arrhythmias. This work was carried out to evaluate the pattern of arrhythmias in Nigerians with heart failure. Materials and methods Thirty subjects with congestive heart failure (CHF), 30 subjects with hypertensive heart disease, and 15 normal subjects with no obvious features of heart disease were evaluated with resting and 24-hour electrocardiographic monitoring and transthoracic echocardiography. Data were analyzed with one-way analysis of variance with post hoc Duncan’s analysis, Fisher’s exact test, and linear regression analysis using SPSS version 16. Results CHF subjects had more instances of supraventricular tachycardia (P=0.005), ventricular extrasystoles (P<0.001), bigeminy (P<0.001), trigeminy (P<0.001), couplets (P<0.001), triplets (P<0.001), and nonsustained ventricular tachycardia (VT) (P=0.003) than the other two control groups. They also showed a significantly longer VT duration (4.6±5.6 seconds) compared with the other groups (P<0.001). Linear regression analysis showed a significant direct relationship between VT and the maximum number of ventricular extrasystoles per hour (P=0.001). Conclusion Cardiac arrhythmias are common in subjects with CHF and are more frequent when compared with patients with hypertensive heart disease and normal subjects. PMID:25870514

  2. Cardiac arrhythmia classification using multi-modal signal analysis.

    PubMed

    Kalidas, V; Tamil, L S

    2016-08-01

    In this paper, as a contribution to the Physionet/Computing in Cardiology 2015 Challenge, we present individual algorithms to accurately classify five different life threatening arrhythmias with the goal of suppressing false alarm generation in intensive care units. Information obtained by analysing electrocardiogram, photoplethysmogram and arterial blood pressure signals was utilized to develop the classification models. Prior to classification, the signals were subject to a signal pre-processing stage for quality analysis. Classification was performed using a combination of support vector machine based machine learning approach and logical analysis techniques. The predicted result for a certain arrhythmia classification model was verified by logical analysis to aid in reduction of false alarms. Separate feature vectors were formed for predicting the presence or absence of each arrhythmia, using both spectral and time-domain information. The training and test data were obtained from the Physionet/CinC Challenge 2015 database. Classification algorithms were written for two different categories of data, namely real-time and retrospective, whose data lengths were 10 s and an additional 30 s, respectively. For the real-time test dataset, sensitivity of 94% and specificity of 82% were obtained. Similarly, for the retrospective test dataset, sensitivity of 94% and specificity of 86% were obtained. PMID:27454417

  3. Nandrolone Plus Moderate Exercise Increases the Susceptibility to Lethal Arrhythmias

    PubMed Central

    Ghorbani Baravati, Hamideh; Joukar, Siyavash; Fathpour, Hossein; Kordestani, Zeinab

    2015-01-01

    Background: Until now, no experimental study has directly assessed the arrhythmogenesis of chronic consumption of anabolic androgenic steroids along with moderate-intensity endurance exercise. Objectives: We evaluated the influence of integration of anabolic androgenic steroids along with moderate-intensity endurance exercise on susceptibility to lethal ventricular arrhythmias in rat. Materials and Methods: The animal groups were as follows: control group (CTL); exercise group (EX) which were under 6 weeks of treadmill exercise; nandrolone group (Nan) which received 5 mg/kg of nandrolone decanoate twice a week; vehicle group (Arach) which received Arachis oil (solvent of nandrolone); trained vehicle group (Arach + Ex); and trained nandrolone group (Nan + Ex). One day after ending of the intervention period, arrhythmia was inducted by intravenous infusion of aconitine and ventricular arrhythmias were recorded. Then malondialdehyde (MDA) and glutathione peroxidase (GPX) of heart tissue were measured. Results: Nandrolone, exercise, and their combination were associated with heart hypertrophy. Exercise could prevent the incremental effect of nandrolone on MDA/GPX ratio. Chronic administration of nandrolone with moderate-intensity endurance exercise had no significant effect on blood pressure, heart rate, and basal electrocardiographic parameters. Combination of nandrolone and exercise significantly increased the incidence of ventricular fibrillation (VF) and reduced the VF latency (P < 0.05). Conclusions: The findings suggest that chronic coadministration of nandrolone with moderate-intensity endurance exercise facilitates the VF occurrence in rat. Complementary studies are needed to elucidate the involved mechanisms of this abnormality. PMID:26396972

  4. Detection of Shockable Ventricular Arrhythmia using Variational Mode Decomposition.

    PubMed

    Tripathy, R K; Sharma, L N; Dandapat, S

    2016-04-01

    Ventricular tachycardia (VT) and ventricular fibrillation (VF) are shockable ventricular cardiac ailments. Detection of VT/VF is one of the important step in both automated external defibrillator (AED) and implantable cardioverter defibrillator (ICD) therapy. In this paper, we propose a new method for detection and classification of shockable ventricular arrhythmia (VT/VF) and non-shockable ventricular arrhythmia (normal sinus rhythm, ventricular bigeminy, ventricular ectopic beats, and ventricular escape rhythm) episodes from Electrocardiogram (ECG) signal. The variational mode decomposition (VMD) is used to decompose the ECG signal into number of modes or sub-signals. The energy, the renyi entropy and the permutation entropy of first three modes are evaluated and these values are used as diagnostic features. The mutual information based feature scoring is employed to select optimal set of diagnostic features. The performance of the diagnostic features is evaluated using random forest (RF) classifier. Experimental results reveal that, the feature subset derived from mutual information based scoring and the RF classifier produces accuracy, sensitivity and specificity values of 97.23 %, 96.54 %, and 97.97 %, respectively. The proposed method is compared with some of the existing techniques for detection of shockable ventricular arrhythmia episodes from ECG. PMID:26798076

  5. Regulation of the fishing activities in the lagoon of Venice, Italy: Results from a socio-economic study

    NASA Astrophysics Data System (ADS)

    Nunes, Paulo A. L. D.; Silvestri, Silvia; Pellizzato, Michele; Boatto, Vasco

    2008-10-01

    In the last years, the overall fish industry in the lagoon of Venice has shown a gradual decline. In order to better understand this process, we carry out a socio-economic questionnaire next to the fisherman population. Questionnaire contains significant qualitative and quantitative data that allow us to evaluate the social and the cultural profile of the respondents, including information with respect to the different technological fishing characteristics involved, type and amount of the species harvested as well as the overall productivity of the activity. Furthermore, the questionnaire contains an economic valuation exercise so as to assess in monetary terms the preferences of the fishermen with respect to different alternative policy options that may characterize a future regulation of this economic activity. Estimation results show that fishermen welcome any regulation initiative that is characterized by: (1) banning all fishing activities during the night, (2) allocating fishing concessions areas to each fishermen in a way that minimize the distance between the fishing area and the harbor, and (3) by introducing of a labeling mechanism that certifies the origin of the product. Moreover, the underlying economic valuation mechanism reveals to sensitive to respondent's motivational profile, including the overall trust and confidence that fisherman community places on the current institutional bodies. This result reveals to be of particular significance when attempting the design of an efficient, widely supported regulation of the fishing activity in the lagoon of Venice.

  6. Annual growth and environmental relationships of the invasive species Sargassum muticum and Undaria pinnatifida in the lagoon of Venice

    NASA Astrophysics Data System (ADS)

    Sfriso, A.; Facca, C.

    2013-09-01

    The growth and autoecology of two alien invasive species: Sargassum muticum and Undaria pinnatifida spreading in the Venice Lagoon were studied monthly, during one year, in two sites of different depth. S. muticum was present year-round and reached its largest size (485 cm) and maximum growth (8.33 cm d-1) at the deepest station. U. pinnatifida was present only from November to May, reaching the highest size (130 cm) in March-April in the shallow station with growth peaks of 2.32 cm d-1. The growth of both species was mainly regulated by water temperature, nutrient concentration, especially nitrogen, and water turbidity. The study highlights the different ecological role already observed for the two species: U. pinnatifida prefers eutrophic areas and is not present along the sea-coastline. Its total standing crop does not exceed 0.2 ktonnes fwt for all the Venice Lagoon. Conversely, S. muticum colonizes areas with a lower eutrophication level, such as the lagoon inlets, reaching a total lagoon standing crop of 4-6 ktonnes fwt.

  7. Microbial deterioration of artistic tiles from the façade of the Grande Albergo Ausonia & Hungaria (Venice, Italy).

    PubMed

    Giacomucci, Lucia; Bertoncello, Renzo; Salvadori, Ornella; Martini, Ilaria; Favaro, Monica; Villa, Federica; Sorlini, Claudia; Cappitelli, Francesca

    2011-08-01

    The Grande Albergo Ausonia & Hungaria (Venice Lido, Italy) has an Art Nouveau polychrome ceramic coating on its façade, which was restored in 2007. Soon after the conservation treatment, many tiles of the façade decoration showed coloured alterations putatively attributed to the presence of microbial communities. To confirm the presence of the biological deposit and the stratigraphy of the Hungaria tiles, stereomicroscope, optical and environmental scanning electron microscope observations were made. The characterisation of the microbial community was performed using a PCR-DGGE approach. This study reported the first use of a culture-independent approach to identify the total community present in biodeteriorated artistic tiles. The case study examined here reveals that the coloured alterations on the tiles were mainly due to the presence of cryptoendolithic cyanobacteria. In addition, we proved that the microflora present on the tiles was generally greatly influenced by the environment of the Hungaria hotel. We found several microorganisms related to the alkaline environment, which is in the range of the tile pH, and related to the aquatic environment, the presence of the acrylic resin Paraloid B72® used during the 2007 treatment and the pollutants of the Venice lagoon. PMID:21286701

  8. A chironomid (Diptera: Chironomidae) midge population study and laboratory evaluation of larvicides against midges inhabiting the lagoon of Venice, Italy.

    PubMed

    Ali, A; Majori, G; Ceretti, G; D'Andrea, F; Scattolin, M; Ferrarese, U

    1985-03-01

    Chironomid larval densities in the saltwater lagoon of Venice, Italy, were assessed in the spring of 1984. Four organophosphates; chlorpyrifos, temephos, fenthion and fenitrothion, and three pyrethroids; cypermethrin, permethrin and deltamethrin, were tested in the laboratory against field-collected larvae. Three industrial formulations of Bacillus thuringiensis var. israelensis (B.t.i.) were also tested as midge larvicides. Only Chironomus salinarius occurred in the benthic samples taken from different sections of the lagoon. The densities of this species ranged from 0 to 38,976 larvae/m2. The highest mean larval density of 15,673/m2 was encountered in a section of the lagoon adjacent to Venice airport and receiving large quantities of raw sewage. The lowest mean density (less than 1 larva/m2) existed in another area of the lagoon receiving discharge from chemical industry. Cypermethrin and permethrin were 21-233X more active against the larvae than the four organophosphates. Chlorpyrifos was the most active organophosphate. Formulations of B.t.i. were economically ineffective against the larvae. PMID:3880214

  9. Benthic foraminifera and trace element distribution: a case-study from the heavily polluted lagoon of Venice (Italy).

    PubMed

    Coccioni, Rodolfo; Frontalini, Fabrizio; Marsili, Andrea; Mana, Davide

    2009-01-01

    Living benthic foraminiferal assemblages were studied in surface samples collected from the lagoon of Venice (Italy) in order to investigate the relationship between these sensitive microorganisms and trace element pollution. Geochemical analysis of sediments shows that the lagoon is affected by trace element pollution (Cd, Cu, Ni, Pb, Zn and Hg) with the highest concentrations in its inner part, which corresponds to the Porto Marghera industrial area. The biocenosis are largely dominated by Ammonia tepida, Haynesina germanica and Cribroelphidium oceanensis and, subordinately, by Aubignyna perlucida, Ammonia parkinsoniana and Bolivina striatula. Biotic and abiotic factors were statistically analyzed with multivariate technique of cluster analysis and principal component analysis. The statistical analysis reveals a strong relationship between trace elements (in particular Mn, Pb and Hg) and the occurrence of abnormalities in foraminiferal tests. Remarkably, greater proportions of abnormal specimens are usually found at stations located close to the heaviest polluted industrial zone of Porto Marghera. This paper shows that benthic foraminifera can be used as useful and relatively speedy and inexpensive bio-indicators in monitoring the health quality of the lagoon of Venice. It also provides a basis for future investigations aimed at unraveling the benthic foraminiferal response to human-induced pollution in marine and transitional marine environments. PMID:19733368

  10. The role of the Arrhythmia Team, an integrated, multidisciplinary approach to treatment of patients with cardiac arrhythmias: results of the European Heart Rhythm Association survey.

    PubMed

    Fumagalli, Stefano; Chen, Jian; Dobreanu, Dan; Madrid, Antonio Hernandez; Tilz, Roland; Dagres, Nikolaos

    2016-04-01

    Management of patients with cardiac arrhythmias is increasingly complex because of continuous technological advance and multifaceted clinical conditions associated with ageing of the population, the presence of co-morbidities and the need for polypharmacy. The aim of this European Heart Rhythm Association Scientific Initiatives Committee survey was to provide an insight into the role of the Arrhythmia Team, an integrated, multidisciplinary approach to management of patients with cardiac arrhythmias. Forty-eight centres from 18 European countries replied to the Web-based questionnaire. The presence of an Arrhythmia Team was reported by 44% of the respondents, whereas 17% were not familiar with this term. Apart from the electrophysiologist, health professionals who should belong to such teams, according to the majority of the respondents, include a clinical cardiologist, a nurse, a cardiac surgeon, a heart failure specialist, a geneticist, and a geriatrician. Its main activity should be dedicated to the management of patients with complex clinical conditions or refractory or inherited forms of arrhythmias. When present, the Arrhythmia Team was considered helpful by 95% of respondents; the majority of centres (79%) agreed that it should be implemented. The Arrhythmia Team seems to be connected to important expectations in the management of cardiac arrhythmias. The efficacy of such an integrated and multidisciplinary approach should be encouraged and tested in clinical practice. PMID:27174994

  11. Computer-assisted instruction of arrhythmia for MS-windows.

    PubMed

    Takeuchi, A; Nara, Y; Ikeda, N; Miyahara, H; Mitobe, H

    1995-01-01

    1. INTRODUCTION. Training in the diagnosis of arrhythmias is an important part of the curriculum for medical students, postgraduates, and paramedical staff. Although several CAI for arrhythmia have been developed [1-3], we could not get CAI software for arrhythmia for the MS-Windows environment. In this report, we present a newly-developed computer-assisted reference system for arrhythmia that functions in the Windows environment. 2. DESCRIPTION OF THE SYSTEM. The system consists of a program and two data files. An MS-Windows program (ECG9405.EXE, 180kB) was compiled using Borland's C++ v.3.1. A binary file (ECPAT.BAS 33kB) includes data of normal and abnormal wave segments of ECG: P wave, PQ interval segment, and QRs complex with/without T wave. A mother file (ECG9405.sys, 57kB) includes 85 data sets to generate ECG waveforms of arrhythmia. Each data set contains a sequence of wave form numbers, the text for questions and answers, and the commands strings. There are five major commands: 1) to create a new window as "wave window"; 2) to make electrocardiogram data; 3) to plot the data on the window; 4) to create a "dialog box" for questions and explanations; and 5) to check the answers. he program gets a data set from the data according to the user's choice. The program then interprets the data set and executes the commands. The wave segment data are plotted in a "wave window" at every 10 milliseconds; this is controlled by the MS-Windows' timer. The timer interval can be changed by selecting the speed button. The ECG waveforms are displayed on a window just like an ordinary ECG monitor with beat sound. Many windows can be created by the user and many ECG waves simultaneously plotted on CRT. 3. USAGE OF THE SYSTEM. The "main window" has a menu that has three items corresponding to the training course: BASIC, TRY, and TEST. Thirty-five types of arrythmias are listed in the "list box" of the windows in BASIC course e.g., sinus arrhythmia, atrial flutter, atrial

  12. Ecological stages of the Venice Lagoon analysed using landing time series data

    NASA Astrophysics Data System (ADS)

    Libralato, Simone; Pranovi, Fabio; Raicevich, Saša; Da Ponte, Filippo; Giovanardi, Otello; Pastres, Roberto; Torricelli, Patrizia; Mainardi, Danilo

    2004-11-01

    The time series of landings in the Venice Lagoon from 1945 to 2001 were analysed with the aim of explaining the ecosystem changes occurred. The comparative analysis of the total landings and mean Trophic Level (mTL) time series allowed to identify four different stages in the lagoon ecosystem. The first period, from 1945 to 1973, was characterised by increasing trends in the landings and their mTL. The second one, from 1974 to 1989, showed a decrease in the landings but still an increase in the mTL. The third period, from 1990 to 1998, had again a positive trend in the landings, but the mTL showed a sharp decline. After 1998, a slight decreasing trend in both mTL and landings was observed: the analyses of the artisanal fishery landings only date back to 1995 this effect. The presence of four distinct periods was also confirmed by the analysis of the trends of other indices estimated using landings data: the Fishing in Balance index (FiB), the Trophic Efficiency (TE) and the Pelagic on Demersal landings ratio (P/D). In the first period, the increasing fishing pressure, along with no evidence of ecosystem crisis, suggested that an increased nutrient discharge was supporting it; analogously, the bottom-up effects had driven the dynamics of the ecosystem also in the second period, when the decrease in nutrient loads caused a shift of the primary producers from planktonic to macrobenthic. The spreading of the Manila clam, a non-native species, and the development of its massive mechanical exploitation have been the main forces driving the ecosystem during the third period, for which, however, no signs of crises were detected. The fourth period showed evidence of the "fishing down the food web" effect. Possible causes of such an effect were investigated and allowed us to conclude that not overfishing, but the effects of mechanical harvesting of the Manila clam had caused relevant impacts on habitat and benthic communities, concluding that the present level of

  13. Long term peatland subsidence: Experimental study and modeling scenarios in the Venice coastland

    NASA Astrophysics Data System (ADS)

    Zanello, Francesca; Teatini, Pietro; Putti, Mario; Gambolati, Giuseppe

    2011-12-01

    Land subsidence in drained cultivated peatlands is responsible for a number of serious environmental concerns and economical problems at both the local and the global scale. In low-lying coastal areas it enhances the risk of flooding, the saltwater contamination of shallow aquifers, and the maintenance costs of the systems that help keep the farmland drained. Since the subsidence is a major consequence of the bio-oxidation of the soil organic fraction in the upper aerated zone, cropped peatlands in temperate and tropic regions are important sources of CO2 into the atmosphere. A 4-year long experimental study has been performed in a drained peatland located south of the Venice Lagoon, Italy, to help calibrate a land subsidence model developed to predict the expected behavior of the ground surface elevation. Continuous monitoring of the hydrological regime and land displacements shows that the vertical movement of the peat surface consists of the superimposition of daily/seasonal time-scale reversible deformations related to soil moisture, depth to the water table, and temperature fluctuations, and long term irreversible subsidence due to peat oxidation. A novel two-step modeling approach to separate the two contributions from the available observations is presented. First, the elastic component is computed by integrating the peat vertical deformations evaluated by a constitutive relationship describing the porosity variation with the moisture content and pore pressure changes implemented into a variably saturated flow equation-based numerical code. The observed trend is then filtered from the computed reversible displacement and is used to calibrate an empirical relationship relating land subsidence rate to drainage depth and soil temperature. The results show that in recent years the subsidence rate ranged from 3 to 15 mm a-1. The large variability is due to the different climate conditions underlying the monitoring period, in particular a wet 2002 and a very dry

  14. Photoacoustic microscopy with an enhanced axial resolution of 5.8 μm

    NASA Astrophysics Data System (ADS)

    Zhang, Chi; Zhou, Yong; Li, Chiye; Wang, Lihong V.

    2014-03-01

    The axial resolution of photoacoustic microscopy (PAM) can be enhanced by reducing the speed of sound within the imaging region of interest. This principle was demonstrated on a previously-reported PAM system, which utilized a 125 MHz ultrasonic transducer for signal detection and the Wiener deconvolution for signal processing. With sound slowed by silicone oil immersion, we have achieved a finest axial resolution of 5.8 μm for PAM, as validated by phantom experiments. The axial resolution was also enhanced in vivo when mouse ears injected with silicone oil were imaged. After injection of silicone oil, the blood vessels were resolved more clearly. When tissue-compatible low-speed liquids become available, this approach may find applications in PAM as well as in other imaging modalities, such as photoacoustic computed tomography and ultrasound imaging.

  15. Initial assessment of the intensity distribution of the 2011 Mw5.8 Mineral, Virginia, earthquake

    USGS Publications Warehouse

    Hough, Susan E.

    2012-01-01

    The intensity data collected by the U.S. Geological Survey (USGS) "Did You Feel It?" (DYFI) Website (USGS, DYFI; http://earthquake.usgs.gov/earthquakes/dyfi/events/se/082311a/us/index.html, last accessed Sept 2011) for the Mw5.8 Mineral, Virginia, earthquake, are unprecedented in their spatial richness and geographical extent. More than 133,000 responses were received during the first week following the earthquake. Although intensity data have traditionally been regarded as imprecise and generally suspect (e.g., Hough 2000), there is a growing appreciation for the potential utility of spatially rich, systematically determined DYFI data to address key questions in earthquake ground-motions science (Atkinson and Wald, 2007; Hauksson et al., 2008).

  16. 18 CFR 5.8 - Notice of commencement of proceeding and scoping document, or of approval to use traditional...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... alternative procedures. 5.8 Section 5.8 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... thereunder at 50 CFR part 402, section 305(b) of the Magnuson-Stevens Fishery Conservation and Management Act and implementing regulations at 50 CFR 600.920, or section 106 of the National Historic...

  17. 18 CFR 5.8 - Notice of commencement of proceeding and scoping document, or of approval to use traditional...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... alternative procedures. 5.8 Section 5.8 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... thereunder at 50 CFR part 402, section 305(b) of the Magnuson-Stevens Fishery Conservation and Management Act and implementing regulations at 50 CFR 600.920, or section 106 of the National Historic...

  18. 18 CFR 5.8 - Notice of commencement of proceeding and scoping document, or of approval to use traditional...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... alternative procedures. 5.8 Section 5.8 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... thereunder at 50 CFR part 402, section 305(b) of the Magnuson-Stevens Fishery Conservation and Management Act and implementing regulations at 50 CFR 600.920, or section 106 of the National Historic...

  19. 18 CFR 5.8 - Notice of commencement of proceeding and scoping document, or of approval to use traditional...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... alternative procedures. 5.8 Section 5.8 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... thereunder at 50 CFR part 402, section 305(b) of the Magnuson-Stevens Fishery Conservation and Management Act and implementing regulations at 50 CFR 600.920, or section 106 of the National Historic...

  20. 18 CFR 5.8 - Notice of commencement of proceeding and scoping document, or of approval to use traditional...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... alternative procedures. 5.8 Section 5.8 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... thereunder at 50 CFR part 402, section 305(b) of the Magnuson-Stevens Fishery Conservation and Management Act and implementing regulations at 50 CFR 600.920, or section 106 of the National Historic...

  1. Delaware Student Testing Program. State Summary Report: Reading, Mathematics, Writing Spring. 2002 Administration: Grades 3, 5, 8, and 10.

    ERIC Educational Resources Information Center

    Delaware State Dept. of Education, Dover. Assessment and Accountability Branch.

    The results in this report, from the fifth administration of the grades 3, 5, 8, and 10 reading, mathematics, and writing portions of the Delaware Student Testing Program (DSTP), represent an important step in Delawares efforts to educate all students to a higher level. Reading, mathematics, and writing data for grades 3, 5, 8, and 10 are…

  2. Brain-heart interactions. The neurocardiology of arrhythmia and sudden cardiac death.

    PubMed Central

    Davis, A M; Natelson, B H

    1993-01-01

    Neuroanatomic connections between the brain and the heart provide links that allow cardiac arrhythmias to occur in response to brain activation. Recognition and analysis of such links in the pathogenesis of malignant cardiac arrhythmia are emphasized in this review. Neurocardiac links have been shown to produce arrhythmia both experimentally and clinically; specific examples, including stroke, epilepsy, and environmental stress are presented. We hypothesize that the individual with a diseased heart has a greater likelihood of experiencing cardiac arrhythmia and sudden cardiac death when the neurocardiac axis is activated. Reviewing possible mechanisms of brain-related arrhythmias, we suggest that the nervous system directs the events leading to cardiac damage by raising catecholamine levels and potentially inducing arrhythmia. PMID:8219819

  3. Primary and secondary structure of 5.8S rRNA from the silkgland of Bombyx mori.

    PubMed Central

    Fujiwara, H; Kawata, Y; Ishikawa, H

    1982-01-01

    Nucleotide sequence of 5.8S rRNA of the silkworm, Bombyx mori has been determined by gel sequencing methods. The 5.8S rRNA was the longest so far reported, with the 5'-terminal sequence several nucleotides longer than those of the other organisms. Upon constructing the secondary structure in accordance with the "burp gun" model (12), the Bombyx 5.8S rRNA formed a wide-open "muzzle" due to several unpaired bases at the ends. The overall structure also appeared less stable with less G . C pairs and more unpaired bases than that of the HeLa 5.8S rRNA. These structural features may be essential for those 5.8S rRNAs which interact with 28S rRNAs containing the hidden break to form a stable complex. PMID:7088713

  4. Device-Based Autonomic Modulation in Arrhythmia Patients: the Role of Vagal Nerve Stimulation

    PubMed Central

    Huang, William A.; Shivkumar, Kalyanam; Vaseghi, Marmar

    2015-01-01

    Opinion statement Vagal nerve stimulation (VNS) has shown promise as an adjunctive therapy for management of cardiac arrhythmias by targeting the cardiac parasympathetic nervous system. VNS has been evaluated in the setting of ischemia-driven ventricular arrhythmias and atrial arrhythmias, as well as a treatment option for heart failure. As better understanding of the complexities of the cardiac autonomic nervous system is obtained, vagal nerve stimulation will likely become a powerful tool in the current cardiovascular therapeutic armamentarium. PMID:25894588

  5. Surveillance of fetal arrhythmias in the outpatient setting: current limitations and call for action.

    PubMed

    Freire, Grace

    2015-12-01

    Surveillance of fetal arrhythmias in the outpatient setting remains limited by lack of monitoring modalities. Despite technological advances made in the field of obstetrics, existing devices are not currently suitable to monitor fetal arrhythmias. In this report, the author describes the current and developing fetal heart rate monitoring technologies including the recent introduction of hand-held Doppler monitors for outpatient surveillance of fetal arrhythmias. PMID:26675609

  6. Exercising arrhythmias and sudden cardiac death in horses: Review of the literature and comparative aspects.

    PubMed

    Navas de Solis, C

    2016-07-01

    Arrhythmias are common in equine athletes during and immediately after exercise. Many of these rhythm variations are not clinically relevant. In horses, a link between different exercising arrhythmias and poor performance or between exercising arrhythmias and sudden cardiac death (SCD) is strongly suspected but not fully understood or proven. SCD during races or competitions is rare, but has catastrophic consequences for the safety of the human partner and public perceptions of welfare during equestrian sports. This review summarises current knowledge of equine exercise arrhythmias and their implications in SCD and compares existing principles and recommendations for equine subjects with those for human athletes. PMID:27156002

  7. Left ventricular function in patients with ventricular arrhythmias and aortic valve disease

    SciTech Connect

    Santinga, J.T.; Kirsh, M.M.; Brady, T.J.; Thrall, J.; Pitt, B.

    1983-02-01

    Forty patients having aortic valve replacement were evaluated preoperatively for ventricular arrhythmia and left ventricular ejection fraction. Arrhythmias were classified as complex or simple using the Lown criteria on the 24-hour ambulatory electrocardiogram; ejection fractions were determined by radionuclide gated blood pool analysis and contrast angiography. The ejection fractions determined by radionuclide angiography were 59.1 +/- 13.1% for 26 patients with simple or no ventricular arrhythmias, and 43.9 +/- 20.3% for 14 patients with complex ventricular arrhythmias (p less than 0.01). Ejection fractions determined by angiography, available for 31 patients, were also lower in patients with complex ventricular arrhythmias (61.1 +/- 16.3% versus 51.4 +/- 13.4%; p less than 0.05). Seven of 9 patients showing conduction abnormalities on the electrocardiogram had complex ventricular arrhythmias. Eight of 20 patients with aortic stenosis had complex ventricular arrhythmias, while 2 of 13 patients with aortic insufficiency had such arrhythmias. It is concluded that decreased left ventricular ejection fraction, intraventricular conduction abnormalities, and aortic stenosis are associated with an increased frequency of complex ventricular arrhythmias in patients with aortic valve disease.

  8. Role of CaMKII in cardiac arrhythmias.

    PubMed

    Hund, Thomas J; Mohler, Peter J

    2015-07-01

    Protein phosphorylation is a central mechanism in vertebrates for the regulation of signaling. With regard to the cardiovascular system, phosphorylation of myocyte targets is critical for the regulation of excitation contraction coupling, metabolism, intracellular calcium regulation, mitochondrial activity, transcriptional regulation, and cytoskeletal dynamics. In fact, pathways that tune protein kinase signaling have been a mainstay for cardiovascular therapies for the past 60 years. The calcium/calmodulin-dependent protein kinase II (CaMKII) is a multifunctional serine/threonine kinase with numerous roles in human physiology. Dysfunction in CaMKII-based signaling has been linked with a host of cardiovascular phenotypes including heart failure and arrhythmia, and CaMKII levels are elevated in human and animal disease models of heart disease. While nearly a decade has been invested in targeting CaMKII for the treatment of heart failure and arrhythmia phenotypes, to date, approaches to target the molecule for antiarrhythmic benefit have been unsuccessful for reasons that are still not entirely clear, although (1) lack of compound specificity and (2) the multitude of downstream targets are likely contributing factors. This review will provide an update on current pathways regulated by CaMKII with the goal of illustrating potential upstream regulatory mechanisms and downstream targets that may be modulated for the prevention of cardiac electrical defects. While the review will cover multiple aspects of CaMKII dysfunction in cardiovascular disease, we have given special attention to the potential of CaMKII-associated late Na(+) current as a novel therapeutic target for cardiac arrhythmia. PMID:25577293

  9. The involvement of TRPC3 channels in sinoatrial arrhythmias

    PubMed Central

    Ju, Yue-Kun; Lee, Bon Hyang; Trajanovska, Sofie; Hao, Gouliang; Allen, David G.; Lei, Ming; Cannell, Mark B.

    2015-01-01

    Atrial fibrillation (AF) is a significant contributor to cardiovascular morbidity and mortality. The currently available treatments are limited and AF continues to be a major clinical challenge. Clinical studies have shown that AF is frequently associated with dysfunction in the sino-atrial node (SAN). The association between AF and SAN dysfunction is probably related to the communication between the SAN and the surrounding atrial cells that form the SAN-atrial pacemaker complex and/or pathological processes that affect both the SAN and atrial simultaneously. Recent evidence suggests that Ca2+ entry through TRPC3 (Transient Receptor Potential Canonical-3) channels may underlie several pathophysiological conditions -including cardiac arrhythmias. However, it is still not known if atrial and sinoatrial node cells are also involved. In this article we will first briefly review TRPC3 and IP3R signaling that relate to store/receptor-operated Ca2+ entry (SOCE/ROCE) mechanisms and cardiac arrhythmias. We will then present some of our recent research progress in this field. Our experiments results suggest that pacing-induced AF in angiotensin II (Ang II) treated mice are significantly reduced in mice lacking the TRPC3 gene (TRPC3−/− mice) compared to wild type controls. We also show that pacemaker cells express TRPC3 and several other molecular components related to SOCE/ROCE signaling, including STIM1 and IP3R. Activation of G-protein coupled receptors (GPCRs) signaling that is able to modulate SOCE/ROCE and Ang II induced Ca2+ homeostasis changes in sinoatrial complex being linked to TRPC3. The results provide new evidence that TRPC3 may play a role in sinoatrial and atrial arrhythmias that are caused by GPCRs activation. PMID:25859221

  10. Quinine-induced arrhythmia in a patient with severe malaria.

    PubMed

    Gunawan, Carta A; Harijanto, Paul N; Nugroho, Agung

    2007-01-01

    It was reported that there was a case of severe malaria patient with jaundice who presented with arrhythmia (premature ventricular contraction) while getting quinine infusion was reported. A man, 25 years old, was admitted to hospital with high fever, chill, vomiting, jaundice. The patient was fully conscious, blood pressure 120/80 mmHg, pulse rate 100 x/minute, regular. On admission, laboratory examination showed Plasmodium falciparum (++++), total bilirubin 8.25 mg/dL, conjugated bilirubin 4.36 mg/dL, unconjugated bilirubin 3.89 mg/dL, potassium 3.52 meq/L Patient was diagnosed as severe malaria with jaundice and got quinine infusion in dextrose 5% 500 mg/8 hour. On the second day the patient had vomitus, diarrhea, tinnitus, loss of hearing. After 30 hours of quinine infusion the patient felt palpitation and electrocardiography (ECG) recording showed premature ventricular contraction (PVC) > 5 x/minute, trigemini, constant type--sinoatrial block, positive U wave. He was treated with lidocaine 50 mg intravenously followed by infusion 1500 mg in dextrose 5%/24 hour and potassium aspartate tablet. Quinine infusion was discontinued and changed with sulfate quinine tablets. Three hours later the patient felt better, the frequency of PVC reduced to 4 - 5 x/minute and on the third day ECG was normal, potassium level was 3.34 meq/L. He was discharged on 7th day in good condition. Quinine, like quinidine, is a chincona alkaloid that has anti-arrhythmic property, although it also pro-arrhythmic that can cause various arrhythmias, including severe arrhythmia such as multiple PVC. Administration of parenteral quinine must be done carefully and with good observation because of its pro-arrhythmic effect, especially in older patients who have heart diseases or patients with electrolyte disorder (hypokalemia) which frequently occurs due to vomiting and or diarrhea in malaria cases. PMID:17297207

  11. Cardiac arrhythmias produced by ultrasound and contrast agents

    NASA Astrophysics Data System (ADS)

    Rota, Claudio

    Ultrasound is used widely in medicine for both diagnostic and therapeutic applications. Ultrasound contrast agents are suspensions of gas-filled microbubbles used to enhance diagnostic imaging. Microbubble contrast agents can increase the likelihood of bioeffects of ultrasound associated with acoustic cavitation. Under certain exposure conditions, the interaction of ultrasound with cardiac tissues can produce cardiac arrhythmias. The general objective of this thesis was to develop a greater understanding of ultrasound-induced premature cardiac beats. The hypothesis guiding this work was that acoustic cavitation is the physical mechanism for the production of arrhythmias with ultrasound. This hypothesis was tested through a series of experiments with mice in vivo and theoretical investigations. Results of this research supported the acoustic cavitation hypothesis. The acoustic pressure threshold for premature beats was significantly lower with microbubble contrast agents present in the blood than without. With microbubbles, the threshold for premature beats was below the current output limits of diagnostic devices. The threshold was not significantly dependent upon contrast agent type and was not influenced by contrast agent dose over three orders of magnitude. Furthermore, the dependence of the threshold on acoustic frequency was consistent with the frequency dependence of acoustic cavitation. Experimentally determined thresholds for premature beats in vivo were in excellent agreement with theoretically estimated thresholds for inertial cavitation. A passive cavitation detector (PCD) was used to measure the acoustic emissions produced by cavitating microbubbles in vivo. A direct correlation between the amplitude of the PCD and the percentage of ultrasound pulses producing a premature beat was consistent with cavitation as a mechanism for this bioeffect. Although this thesis focused on the mechanistic understanding of ultrasound-induced arrhythmias, more persistent

  12. Smad1/5/8 are myogenic regulators of murine and human mesoangioblasts

    PubMed Central

    Costamagna, Domiziana; Quattrocelli, Mattia; van Tienen, Florence; Umans, Lieve; de Coo, Irineus F. M.; Zwijsen, An; Huylebroeck, Danny; Sampaolesi, Maurilio

    2016-01-01

    Mesoangioblasts (MABs) are vessel-associated stem cells that express pericyte marker genes and participate in skeletal muscle regeneration. Molecular circuits that regulate the myogenic commitment of MABs are still poorly characterized. The critical role of bone morphogenetic protein (BMP) signalling during proliferation and differentiation of adult myogenic precursors, such as satellite cells, has recently been established. We evaluated whether BMP signalling impacts on the myogenic potential of embryonic and adult MABs both in vitro and in vivo. Addition of BMP inhibited MAB myogenic differentiation, whereas interference with the interactions between BMPs and receptor complexes induced differentiation. Similarly, siRNA-mediated knockdown of Smad8 in Smad1/5-null MABs or inhibition of SMAD1/5/8 phosphorylation with Dorsomorphin (DM) also improved myogenic differentiation, demonstrating a novel role of SMAD8. Moreover, using a transgenic mouse model of Smad8 deletion, we demonstrated that the absence of SMAD8 protein improved MAB myogenic differentiation. Furthermore, once injected into α-Sarcoglycan (Sgca)-null muscles, DM-treated MABs were more efficacious to restore α-sarcoglycan (αSG) protein levels and re-establish functional muscle properties. Similarly, in acute muscle damage, DM-treated MABs displayed a better myogenic potential compared with BMP-treated and untreated cells. Finally, SMADs also control the myogenic commitment of human MABs (hMABs). BMP signalling antagonists are therefore novel candidates to improve the therapeutic effects of hMABs. PMID:26450990

  13. Geotechnical aspects in the epicentral region of the 2011, Mw5.8 Mineral, Virginia earthquake

    USGS Publications Warehouse

    Green, Russell A.; Lasley, Samuel; Carter, Mark W.; Munsey, Jeffrey W.; Maurer, Brett W.; Tuttle, Martitia P.

    2015-01-01

    A reconnaissance team documented the geotechnical and geological aspects in the epicentral region of the Mw (moment magnitude) 5.8 Mineral, Virginia (USA), earthquake of 23 August 2011. Tectonically and seismically induced ground deformations, evidence of liquefaction, rock slides, river bank slumps, ground subsidence, performance of earthen dams, damage to public infrastructure and lifelines, and other effects of the earthquake were documented. This moderate earthquake provided the rare opportunity to collect data to help assess current geoengineering practices in the region, as well as to assess seismic performance of the aging infrastructure in the region. Ground failures included two marginal liquefaction sites, a river bank slump, four minor rockfalls, and a ~4-m-wide, ~12-m-long, ~0.3-m-deep subsidence on a residential property. Damage to lifelines included subsidence of the approaches for a bridge and a water main break to a heavily corroded, 5-cm-diameter valve in Mineral, Virginia. Observed damage to dams, landfills, and public-use properties included a small, shallow slide in the temporary (“working”) clay cap of the county landfill, damage to two earthen dams (one in the epicentral region and one further away near Bedford, Virginia), and substantial structural damage to two public school buildings.

  14. Pyruvate Dehydrogenase Kinase 4 Promotes Vascular Calcification via SMAD1/5/8 Phosphorylation

    PubMed Central

    Lee, Sun Joo; Jeong, Ji Yun; Oh, Chang Joo; Park, Sungmi; Kim, Joon-Young; Kim, Han-Jong; Doo Kim, Nam; Choi, Young-Keun; Do, Ji-Yeon; Go, Younghoon; Ha, Chae-Myung; Choi, Je-Yong; Huh, Seung; Ho Jeoung, Nam; Lee, Ki-Up; Choi, Hueng-Sik; Wang, Yu; Park, Keun-Gyu; Harris, Robert A.; Lee, In-Kyu

    2015-01-01

    Vascular calcification, a pathologic response to defective calcium and phosphate homeostasis, is strongly associated with cardiovascular mortality and morbidity. In this study, we have observed that pyruvate dehydrogenase kinase 4 (PDK4) is upregulated and pyruvate dehydrogenase complex phosphorylation is increased in calcifying vascular smooth muscle cells (VSMCs) and in calcified vessels of patients with atherosclerosis, suggesting that PDK4 plays an important role in vascular calcification. Both genetic and pharmacological inhibition of PDK4 ameliorated the calcification in phosphate-treated VSMCs and aortic rings and in vitamin D3-treated mice. PDK4 augmented the osteogenic differentiation of VSMCs by phosphorylating SMAD1/5/8 via direct interaction, which enhances BMP2 signaling. Furthermore, increased expression of PDK4 in phosphate-treated VSMCs induced mitochondrial dysfunction followed by apoptosis. Taken together, our results show that upregulation of PDK4 promotes vascular calcification by increasing osteogenic markers with no adverse effect on bone formation, demonstrating that PDK4 is a therapeutic target for vascular calcification. PMID:26560812

  15. Human platelets produce 14,15-oxido-5,8,11-eicosatrienoic acid from phosphatidylinositol

    SciTech Connect

    Ballou, L.R.; Lam, B.K.; Wong, P.Y.K.; Cheung, W.Y.

    1987-05-01

    Human platelets contain a soluble enzyme or enzyme system which catalyzes the formation of a compound more polar than arachidonate from 2-arachidonyl-sn-phosphatidylinositol (PtdIns). The C-value and mass spectrum of the compound appears similar to the reported values of 14,15-oxido-5,8,11-eicosatrienoic acid (EET). 2-Arachidonyl-sn-phosphatidylcholine, 2-arachidonyl-sn-phosphatidylethanolamine and arachidonic acid were not substrates for EET production. The reaction was Ca/sup 2 +/-dependent and insensitive to aspirin, mepacrin and indomethacin. EET formation was greatly reduced under nitrogen or carbon monoxide, however, exposure to atmospheric air rapidly restored EET production to a rate comparable to that under air. Further, neither NADPH nor cyanide affected EET formation, suggesting that a cytochrome P-450 system was not involved. Intact platelets prelabeled with (/sup 14/C)arachidonic acid generated at least 0.5 nmole of EET/10/sup 9/ platelets in response to thrombin; other agonists such as collagen, epinephrine, ADP or ionophore A23187 were not effective. Collectively, these data suggest that human platelets possess an enzyme system which appears to catalyze epoxidation of the arachidonyl moiety of PtdIns and its subsequent hydrolysis to yield EET.

  16. Farmland productivity under stress conditions: a field scale monitoring and modeling study on the Venice coastland, Italy

    NASA Astrophysics Data System (ADS)

    Manoli, Gabriele; Scudiero, Elia; Putti, Mario; Morari, Francesco; Teatini, Pietro

    2014-05-01

    The Venice coastland, Italy, is a precarious environment jeopardized by both natural and anthropogenic factors. Due to a land elevation below sea level and the presence of sandy paleo-channels, salinization of soil and shallow groundwater is posing a serious threat to the agricultural productivity of the region. In order to identify and quantify the impacts of the saltwater contamination on crop productivity an integrated monitoring and modeling approach is used. A representative 21 ha basin cultivated with maize crop has been extensively studied by soil sampling, geophysical surveys, continuous hydrological monitoring and crop yield distribution. Based on field observations a field-scale model of soil moisture dynamics coupled with plant transpiration, photosynthesis and growth has been developed and applied at the site.

  17. Distribution of Escherichia coli in a coastal lagoon (Venice, Italy): Temporal patterns, genetic diversity and the role of tidal forcing.

    PubMed

    Perini, L; Quero, G M; García, E Serrano; Luna, G M

    2015-12-15

    Despite its worldwide importance as fecal indicator in aquatic systems, little is known about the diversity of Escherichia coli in the environment and the factors driving its spatial distribution. The city of Venice (Italy), lying at the forefront of a large European lagoon, is an ideal site to study the mechanisms driving the fate of fecal bacteria, due to the huge fluxes of tourists, the city's unique architecture (causing poor efficiency of sewages treatment), and the long branching network of canals crossing the city. We summarize the results of a multi-year investigation to study the temporal dynamics of E. coli around the city, describe the population structure (by assigning isolates to their phylogenetic group) and the genotypic diversity, and explore the role of environmental factors in determining its variability. E. coli abundance in water was highly variable, ranging from being undetectable up to 10(4) Colony Forming Units (CFU) per 100 ml. Abundance did not display significant relationships with the water physico-chemical variables. The analysis of the population structure showed the presence of all known phylogroups, including extra-intestinal and potentially pathogenic ones. The genotypic diversity was very high, as likely consequence of the heterogeneous input of fecal bacteria from the city, and showed site-specific patterns. Intensive sampling during the tidal fluctuations highlighted the prominent role of tides, rather than environmental variables, as source of spatial variation, with a more evident influence in water than sediments. These results, the first providing information on the genetic properties, spatial heterogeneity and influence of tides on E. coli populations around Venice, have implications to manage the fecal pollution, and the associated waterborne disease risks, in coastal cities lying in front of lagoons and semi-enclosed basins. PMID:26402879

  18. Radar-driven high-resolution hydro-meteorological forecasts of the 26 September 2007 Venice flash flood

    NASA Astrophysics Data System (ADS)

    Rossa, Andrea M.; Laudanna Del Guerra, Franco; Borga, Marco; Zanon, Francesco; Settin, Tommaso; Leuenberger, Daniel

    2010-11-01

    SummaryThis study aims to assess the feasibility of assimilating carefully checked radar rainfall estimates into a numerical weather prediction (NWP) to extend the forecasting lead time for an extreme flash flood. The hydro-meteorological modeling chain includes the convection-permitting NWP model COSMO-2 and a coupled hydrological-hydraulic model. Radar rainfall estimates are assimilated into the NWP model via the latent heat nudging method. The study is focused on 26 September 2007 extreme flash flood which impacted the coastal area of North-eastern Italy around Venice. The hydro-meteorological modeling system is implemented over the 90 km2 Dese river basin draining to the Venice Lagoon. The radar rainfall observations are carefully checked for artifacts, including rain-induced signal attenuation, by means of physics-based correction procedures and comparison with a dense network of raingauges. The impact of the radar rainfall estimates in the assimilation cycle of the NWP model is very significant. The main individual organized convective systems are successfully introduced into the model state, both in terms of timing and localization. Also, high-intensity incorrectly localized precipitation is correctly reduced to about the observed levels. On the other hand, the highest rainfall intensities computed after assimilation underestimate the observed values by 20% and 50% at a scale of 20 km and 5 km, respectively. The positive impact of assimilating radar rainfall estimates is carried over into the free forecast for about 2-5 h, depending on when the forecast was started. The positive impact is larger when the main mesoscale convective system is present in the initial conditions. The improvements in the precipitation forecasts are propagated to the river flow simulations, with an extension of the forecasting lead time up to 3 h.

  19. Eight years of groundwater monitoring at the building site of the MOSE system for the safeguard of Venice

    NASA Astrophysics Data System (ADS)

    Casasso, Alessandro; Sethi, Rajandrea; Di Molfetta, Antonio

    2015-04-01

    The survival of Venice is threatened by the continuous increase of frequency and intensity of tidal floods. To prevent these events, a safeguarding system known as MOSE is under construction at the inlets of the Lagoon of Venice. Four arrays of mobile barriers will be lifted in the case of exceptionally high tides (>1.10 m) to insulate the Lagoon. The prefabrication of the mobile barriers required a large construction area close to the final installation sites. Given the lack of space in the inlets of Lido and Chioggia, two basins of the future navigation locks were used for this purpose, and a system of water pumps and wells was therefore installed in each site to ensure the accessibility and safety of the construction areas. The impact of dewatering on the aquifers on the mainland in Punta Sabbioni (inlet of Lido) was monitored by means of continuous hydraulic head measurements in a network 25 piezometers, 11 screened in the phreatic aquifer and 14 in the shallowest confined aquifer. These aquifers are separated by a 5 m thick clayey aquiclude, and a 30 m thick impervious layer isolates them from the underlying confined aquifers, which were therefore not monitored. Each monitoring well was equipped with an automatic water pressure transducer and the hourly recorded hydraulic heads were compensated with the barometric pressure. The time series were compared with the natural driving forces (tides, rainfall, evapotranspiration) and the anthropogenic impact sources (dewatering pumping, slurry walls, land reclamation channels). The dynamics of seawater intrusion were also studied through monthly measurements of the vertical profiles of the electrical conductivity (EC) of groundwater. The monitoring activity was successful in assessing the impacts of the construction works. A drawdown was observed in the confined aquifer due to the dewatering pumping, with a maximum displacement of some 5 m on the mainland and an extension of some 1000 m from the dewatered basin. By

  20. Eight years of groundwater monitoring at the building site of the MOSE system for the safeguard of Venice

    NASA Astrophysics Data System (ADS)

    Casasso, Alessandro; Sethi, Rajandrea; Di Molfetta, Antonio

    2015-04-01

    The survival of Venice is threatened by the continuous increase of frequency and intensity of tidal floods. To prevent these events, a safeguarding system known as MOSE is under construction at the inlets of the Lagoon of Venice. Four arrays of mobile barriers will be lifted in the case of exceptionally high tides (>1.10 m) to insulate the Lagoon. The prefabrication of the mobile barriers required a large construction area close to the final installation sites. Given the lack of space in the inlets of Lido and Chioggia, two basins of the future navigation locks were used for this purpose, and a system of water pumps and wells was therefore installed in each site to ensure the accessibility and safety of the construction areas. The impact of dewatering on the aquifers on the mainland in Punta Sabbioni (inlet of Lido) was monitored by means of continuous hydraulic head measurements in a network 25 piezometers, 11 screened in the phreatic aquifer and 14 in the shallowest confined aquifer. These aquifers are separated by a 5 m thick clayey aquiclude, and a 30 m thick impervious layer isolates them from the underlying confined aquifers, which were therefore not monitored. Each monitoring well was equipped with an automatic water pressure transducer and the hourly recorded hydraulic heads were compensated with the barometric pressure. The time series were compared with the natural driving forces (tides, rainfall, evapotranspiration) and the anthropogenic impact sources (dewatering pumping, slurry walls, land reclamation channels). The dynamics of seawater intrusion were also studied through monthly measurements of the vertical profiles of the electrical conductivity (EC) of groundwater. The monitoring activity was successful in assessing the impacts of the construction works. A drawdown was observed in the confined aquifer due to the dewatering pumping, with a maximum displacement of some 5 m on the mainland and an extension of some 1000 m from the dewatered basin. By

  1. Detection and Prevention of Cardiac Arrhythmias During Space Flight

    NASA Technical Reports Server (NTRS)

    Pillai, Dilip; Rosenbaum, David S.; Liszka, Kathy J.; York, David W.; Mackin, Michael A.; Lichter, Michael J.

    2004-01-01

    There have been reports suggesting that long-duration space flight might lead to an increased risk of potentially serious heart rhythm disturbances. If space flight does, in fact, significantly decrease cardiac electrical stability, the effects could be catastrophic, potentially leading to sudden cardiac death. It will be important to determine the mechanisms underlying this phenomenon in order to prepare for long-term manned lunar and interplanetary missions and to develop appropriate countermeasures. Electrical alternans affecting the ST segment and T-wave have been demonstrated to be common among patients at increased risk for ventricular arrhythmias. Subtle electrical alternans on the ECG may serve as a noninvasive marker of vulnerability to ventricular arrhythmias. We are studying indices of electrical instability in the heart for long term space missions by non-invasively measuring microvolt level T-wave alternans in a reduced gravity environment. In this investigation we are using volunteer subjects on the KC-135 aircraft as an initial study of the effect of electrical adaptation of the heart to microgravity. T-wave alternans will be analyzed for heart rate variability and QT restitution curve plotting will be compared for statistical significance.

  2. Klotho protein lowered in senile patients with brady sinus arrhythmia

    PubMed Central

    Wang, Ying; Yang, Wei; Zheng, Ernv; Zhang, Wei; Su, Xianming

    2015-01-01

    Objective: To explore the correlationship between brady sinus arrhythmia and the levels of serum klotho protein in aged. Methods: 104 patients over 75 years old with brady sinus arrhythmia (experiment group) were enrolled, including 34 cases of sinus arrest, 43 cases of sinus bradycardia and 25 cases of atrioventricular block. 109 patients over 75 years old without brady sinus arrhymia were chosen as control group. All subjects were monitored by Holter. The levels of serum klotho protein were detected and compared among three groups. The correlation between the frequency of sinus arrest and the levels of serum klotho protein was analyzed simultaneously. Results: The levels of serum klotho protein in experiment group were lower than that in control group (P<0.01); the sinus arrest frequency was negatively correlated with the levels of serum klotho protien. The levels of serum klotho protein in patients with sinus arrest were lower than that with sinus bradycardia and atrioventricularblock (P<0.05). But there was no significant difference between sinus bradycardia group and atrioventricular block group. Conclusion: The levels of serum klotho protein may reflect the function of sinoatrial node and could be used as an index to estimate the function of sinoatrial node. PMID:26550342

  3. BPC 157: The counteraction of succinylcholine, hyperkalemia, and arrhythmias.

    PubMed

    Stambolija, Vasilije; Stambolija, Tamara Perleta; Holjevac, Jadranka Katancic; Murselovic, Tamara; Radonic, Jelena; Duzel, Viktor; Duplancic, Bozidar; Uzun, Sandra; Zivanovic-Posilovic, Gordana; Kolenc, Danijela; Drmic, Domagoj; Romic, Zeljko; Seiwerth, Sven; Sikiric, Predrag

    2016-06-15

    After the demonstration of its life-saving effect in severe hyperkalemia and the recovery of skeletal muscle after injury, pentadecapeptide BPC 157 has been shown to attenuate the local paralytic effect induced by succinylcholine, in addition to systemic muscle disability (and consequent muscle damage). Hyperkalemia, arrhythmias and a rise in serum enzyme values, were counteracted in rats. Assessments were made at 3 and 30min and 1, 3, 5, and 7 days after succinylcholine administration (1.0mg/kg into the right anterior tibial muscle). BPC 157 (10µg/kg, 10ng/kg) (given intraperitoneally 30min before or immediately after succinylcholine or per-orally in drinking water through 24h until succinylcholine administration) mitigated both local and systemic disturbances. BPC 157 completely eliminated hyperkalemia and arrhythmias, markedly attenuated or erradicated behavioral agitation, muscle twitches, motionless resting and completely eliminated post-succinylcholine hyperalgesia. BPC 157 immediately eliminated leg contractures and counteracted both edema and the decrease in muscle fibers in the diaphragm and injected/non-injected anterior tibial muscles. Therefore, the depolarizing neuromuscular blocker effects of succinylcholine were successfully antagonized. PMID:27060013

  4. Introduction: Mapping and control of complex cardiac arrhythmias.

    PubMed

    Christini, David J.; Glass, Leon

    2002-09-01

    This paper serves as an introduction to the Focus Issue on mapping and control of complex cardiac arrhythmias. We first introduce basic concepts of cardiac electrophysiology and describe the main clinical methods being used to treat arrhythmia. We then provide a brief summary of the main themes contained in the articles in this Focus Issue. In recent years there have been important advances in the ability to map the spread of excitation in intact hearts and in laboratory settings. This work has been combined with simulations that use increasingly realistic geometry and physiology. Waves of excitation and contraction in the heart do not always propagate with constant velocity but are often subject to instabilities that may lead to fluctuations in velocity and cycle time. Such instabilities are often treated best in the context of simple one- or two-dimensional geometries. An understanding of the mechanisms of propagation and wave stability is leading to the implementation of different stimulation protocols in an effort to modify or eliminate abnormal rhythms. (c) 2002 American Institute of Physics. PMID:12779601

  5. Review of complementary and alternative medical treatment of arrhythmias.

    PubMed

    Brenyo, Andrew; Aktas, Mehmet K

    2014-03-01

    Complementary and alternative medical (CAM) therapies are commonly used by patients for the treatment of medical conditions spanning the full spectrum of severity and chronicity. The use of alternative remedies, both herbal and others, for conditions lacking effective medical treatment, is on the increase. Included within this categorization, arrhythmic disease-absent effective catheter-based therapy or with medical therapy limited by the toxicities of contemporary antiarrhythmic agents is frequently managed by patients with CAM therapies without their practitioner's knowledge and in the face of potential herb-drug toxicities. This study reviews 9 CAM therapies: 7 individual herbal therapies along with acupuncture and yoga that have been studied and reported as having an antiarrhythmic effect. The primary focuses are the proposed antiarrhythmic mechanism of each CAM agent along with interactions between the CAM therapies and commonly prescribed medical therapy for arrhythmia patients. We stress persistent vigilance on the part of the provider in discussing the use of herbal or other CAM agents within the arrhythmia population. PMID:24528618

  6. Evaluation and management of arrhythmia in the athletic patient.

    PubMed

    Lampert, Rachel

    2012-01-01

    Athletes may present with palpitations, syncope, or arrest resulting in the diagnosis of arrhythmia, or screening may result in diagnosis of conditions with predisposition to arrhythmia. This chapter focuses on 3 common arrhythmic conditions in athletes-atrial fibrillation, premature ventricular contractions (PVCs), and the athlete with an implanted device. (1) Atrial fibrillation: most studies show that atrial fibrillation is more common in competitive athletes, particularly those participating in long-term endurance sports. Postulated mechanisms include morphologic changes such as atrial dilatation, autonomic changes such as increased vagal tone, or inflammatory changes due to sports participation. Treatment options include long-term antiarrhythmic agents, "pill in the pocket" medications, or radiofrequency ablation, a highly successful procedure in athletes. (2) Premature ventricular contractions: data conflict on whether the incidence of PVCs is increased in highly trained individuals. Very frequent PVCs in athletes, however, can be a manifestation of underlying heart disease, and athletes presenting with PVCs should undergo evaluation. In the absence of underlying heart disease, PVCs do not carry a poor prognosis, and US guidelines do not recommend restriction from sports. (3) Implanted devices: the safety of sports for the athlete with an implanted device is unknown, and current guidelines recommend against participation in vigorous competitive sports, based on postulated risks including failure to defibrillate and risk of injury. Many athletes with defibrillators and pacemakers do participate in sports. Ongoing research will better delineate the risks of sports for the athlete with an implanted device. PMID:22386293

  7. Arrhythmias, Sudden Cardiac Death and incapacitation of pilots

    PubMed Central

    Mantziari, L; Styliadis, C; Kourtidou-Papadeli, C; Styliadis, I

    2008-01-01

    Inflight medical emergencies occur at a rate of 20 to 100 per million passengers, with a death rate of 0.1 to 1 per million. Cardiac, neurologic, and respiratory complaints comprise the more serious emergencies, as defined by aircraft diversion or use of ground-based medical assistance. In this paper, we review changes seen in the resting electrocardiogram in normal individuals exposed to high altitude, alongside important implications for patients with heart diseases in high altitude exposures and the possible effects of high altitude to permanent cardiac pacemakers. Arrhythmias in pilots and public safety are revisited together with the guidelines of the Joint Aviation Requirements (JAR) in Europe. The situation of Military flights is also discussed. Physicians ought to become knowledgeable about the specific medical job standards for their patients when asked to render opinions regarding fitness to fly. A database must be established to obtain prospective data that defines the risk of accidents in patients who are or were being treated for arrhythmias. Current guidelines could then be updated and revised as appropriate. PMID:19050752

  8. Identification by affinity chromatography of the eukaryotic ribosomal proteins that bind to 5.8 S ribosomal ribonucleic acid.

    PubMed

    Ulbrich, N; Lin, A; Wool, I G

    1979-09-10

    The proteins that bind to rat liver 5.8 S ribosomal ribonucleic acid were identified by affinity chromatography. The nucleic acid was oxidized with periodate and coupled by its 3'-terminus to Sepharose 4B through and adipic acid dihydrazide spacer. The ribosomal proteins that associate with the immobilized 5.8 S rRNA were identified by polyacrylamide gel electrophoresiss: they were L19, L8, and L6 from the 60 S subunit; and S13 and S9 from the small subparticle. Small amounts of L14, L17', L18, L27/L27', and L35', and of S11, S15, S23/S24, and S26 also were bound to the affinity column, but whether they associate directly and specifically with 5.8 S rRNA is not known. Escherichia coli ribosomal proteins did not bind to the rat liver 5.8 S rRNA affinity column. PMID:468846

  9. Applying non-linear dynamics to atrial appendage flow data to understand and characterize atrial arrhythmia

    SciTech Connect

    Chandra, S.; Grimm, R.A.; Katz, R.; Thomas, J.D.

    1996-06-01

    The aim of this study was to better understand and characterize left atrial appendage flow in atrial fibrillation. Atrial fibrillation and flutter are the most common cardiac arrhythmias affecting 15% of the older population. The pulsed Doppler velocity profile data was recorded from the left atrial appendage of patients using transesophageal echocardiography. The data was analyzed using Fourier analysis and nonlinear dynamical tools. Fourier analysis showed that appendage mechanical frequency ({ital f{sub f}}) for patients in sinus rhythm was always lower (around1 Hz) than that in atrial fibrillation (5-8 Hz). Among patients with atrial fibrillation spectral power below {ital f{sub f}} was significantly different suggesting variability within this group of patients. Results that suggested the presence of nonlinear dynamics were: a) the existence of two arbitrary peak frequencies {ital f{sub 1}, f{sub 2}}, and other peak frequencies as linear combinations thereof ({ital mf{sub 1}{+-}nf{sub 2}}), and b) the similarity between the spectrum of patient data and that obtained using the Lorenz equation. Nonlinear analysis tools, including Phase plots and differential radial plots, were also generated from the velocity data using a delay of 10. In the phase plots, some patients displayed a torus-like structure, while others had a more random-like pattern. In the differential radial plots, the first set of patients (with torus-like phase plots) showed fewer values crossing an arbitrary threshold of 10 than did the second set (8 vs. 27 in one typical example). The outcome of cardioversion was different for these two set of patients. Fourier analysis helped to: differentiate between sinus rhythm and atrial fibrillation, understand the characteristics of the wide range of atrial fibrillation patients, and provide hints that atrial fibrillation could be a nonlinear process. Nonlinear dynamical tools helped to further characterize and sub-classify atrial fibrillation.

  10. Unveiling specific triggers and precipitating factors for fatal cardiac events in inherited arrhythmia syndromes.

    PubMed

    Nakajima, Tadashi; Kaneko, Yoshiaki; Kurabayashi, Masahiko

    2015-01-01

    Patients with inherited arrhythmia syndromes, such as long QT syndrome, Brugada syndrome, early repolarization syndrome, catecholaminergic polymorphic ventricular tachycardia, and their latent forms, are at risk for fatal arrhythmias. These diseases are typically associated with genetic mutations that perturb cardiac ionic currents. The analysis of cardiac events by genotype-phenotype correlation studies has revealed that fatal arrhythmias in some genotypes are triggered by physical or emotional stress, and those in the others are more likely to occur during sleep or at rest. Thus, the risk stratification and management of affected patients differ strikingly according to the genetic variant of the inherited arrhythmia syndrome. Risk stratification may be further refined by considering the precipitating factors, such as drugs, bradycardia, electrolyte disturbances, fever, and cardiac memory. Moreover, an increasing number of studies imply that the susceptibility of fatal arrhythmias in patients with acute coronary syndrome or takotsubo cardiomyopathy is at least partly ascribed to the genetic variants causing inherited arrhythmia syndromes. In this article, we review the recent advances in the understanding of the molecular genetics and genotype-phenotype correlations in inherited arrhythmia syndromes and consider the triggers and precipitating factors for fatal arrhythmias in these disorders. Further studies to explore the triggers and precipitating factors specific to the genotypes and diseases are needed for better clinical management. PMID:25925977

  11. 78 FR 36787 - Rechanneling the Current Cardiac Risk Paradigm: Arrhythmia Risk Assessment During Drug...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-19

    ... HUMAN SERVICES Food and Drug Administration Rechanneling the Current Cardiac Risk Paradigm: Arrhythmia... the Current Cardiac Risk Paradigm: Arrhythmia Risk Assessment During Drug Development Without the... the current guidelines, and the importance of a uniform assay schema. Date and Time: The...

  12. Cardiac arrhythmias associated with a liquid protein diet for the treatment of obesity

    SciTech Connect

    Lantigua, R.A.; Amatruda, J.M.; Biddle, T.L.; Forbes, G.B.; Lockwood, D.H.

    1980-09-25

    Our data demonstrate that a liquid protein diet is frequently associated with potentially life-threatening arrhythmias that are not detected on routine electrocardiography. Several studies of metabolic balance failed to reveal a cause for these arrhythmias. We recommended that the use of liquid protein diets should be terminated pending further investigation of the causes and prevention of the cardiac toxicity.

  13. Effect of beta-blockers on arrhythmias during six weeks after suspected myocardial infarction.

    PubMed

    Roland, J M; Wilcox, R G; Banks, D C; Edwards, B; Fentem, P H; Hampton, J R

    1979-09-01

    Twenty-four-hour electrocardiographic tape-recording was used to investigate the incidence of arrhythmias in patients with suspected myocardial infarction who were receiving either propranolol, atenolol, or placebo. Recordings begun within 24 hours after admission to a coronary care unit showed that 76% of patients eventually found to have had a myocardial infarction had ventricular arrhythmias of a type generally regarded as serious, whereas of patients in whom myocardial infarction was not substantiated, only 24% had such arrhythmias. At one and six weeks after admission the incidence of arrhythmias ranged from 25% to 33% irrespective of diagnosis. Of patients monitored at both one and six weeks, however, only 5% had arrhythmias on each occasion. Patients treated with propranolol and atenolol showed a similar incidence of arrhythmias to those taking placebo. There was no difference in the incidence or type of arrhythmias recorded between patients who died and those who were still alive at six weeks.These results confirm that "serious" ventricular arrythmias occur in most patients during the acute phase of myocardial infarction and suggest that they do not constitute an independent risk factor. Beta-blockers showed little evidence of useful antiarrhythmic action in the dosage used, but increasing the dosage in suspected myocardial infarction is not practicable because of the risk of hypotension. The findings raise grave doubts about the value of studying arrhythmias to assess drugs intended to reduce mortality from myocardial infarction. PMID:387170

  14. Arrhythmia triggers in heart failure: the smoking gun of [Ca2+]i dysregulation.

    PubMed

    Aistrup, Gary L; Balke, C William; Wasserstrom, J Andrew

    2011-11-01

    Among the most serious problems associated with heart failure is the increased likelihood of life-threatening arrhythmias. Both triggered and reentrant arrhythmias in heart failure may arise as a result of aberrant intracellular Ca cycling. This article presents some new ideas, based on recent studies, about how altered Ca cycling in heart failure might serve as the cellular basis for arrhythmogenesis. PMID:21699870

  15. Maximizing the Effectiveness of Ablation for Arrhythmias in the Congenital Heart Patients.

    PubMed

    Arujuna, Aruna; de Bono, Joseph

    2016-07-01

    Arrhythmias are common in adults with congenital heart disease and account for a large proportion of hospitalizations. The complex anatomical heterogeneity, often in the presence of a delicate hemodynamic system, presents a significant electrophysiological challenge. This review outlines current clinical practice and advances in maximizing the effectiveness of ablation for arrhythmias in congenital heart patients. PMID:27289368

  16. Discriminative sparse coding of ECG during ventricular arrhythmias using LC-K-SVD approach.

    PubMed

    Kalaji, I; Balasundaram, K; Umapathy, K

    2015-01-01

    Ventricular tachycardia (VT) and ventricular fibrillation (VF) are two major types of ventricular arrhythmias that results due to abnormalities in the electrical activation in the ventricles of the heart. VF is the lethal of the two arrhythmias, which may lead to sudden cardiac death. The treatment options for the two arrhythmias are different. Therefore, detection and characterization of the two arrhythmias is critical to choose appropriate therapy options. Due to the time-varying nature of the signal content during cardiac arrhythmias, modeling and extracting information from them using time and frequency localized functions would be ideal. To this effect, in this work, we perform discriminative sparse coding of the ECG during ventricular arrhythmia with hybrid time-frequency dictionaries using the recently introduced Label consistent K-SVD (LC-K-SVD) approach. Using 944 segments of ventricular arrhythmias extracted from 23 patients in the Malignant Ventricular Ectopy and Creighton University Tachy-Arrhythmia databases, an overall classification accuracy of 71.55% was attained with a hybrid dictionary of Gabor and symlet4 atoms. In comparison, for the same database and non-trained dictionary (i.e the original dictionary) the classification accuracy was found to be 62.71%. In addition, the modeling error using the trained dictionary from LC-K-SVD approach was found to be significantly lower to the one using the non-trained dictionary. PMID:26737466

  17. EFFECTS OF 4% AND 5% CARBOXYHEMOGLOBIN ON ARRHYTHMIA PRODUCTION IN PATIENTS WITH CORONARY ARTERY DISEASE

    EPA Science Inventory

    Sudden death frequently occurs from coronary artery disease. t almost always results from cardiac arrhythmias and is often the first and only clinically recognizable manifestation of the disease process (1). ecause of the relations among cardiac arrhythmias, sudden death, and cor...

  18. Aconitine "challenge" test reveals a single whole-body exposure to diesel exhaust increases cardiac arrhythmia risk in hypertensive rats

    EPA Science Inventory

    Epidemiological studies demonstrate a significant association between cardiac electrical dysfunction, arrhythmias and air pollution exposure. Sensitivity to aconitine-induced arrhythmia has been used repeatedly to examine the factors that increase the risk of such cardiac electri...

  19. Aconitine Challenge Test Reveals a Single Exposure to Air Pollution Causes Increased Cardiac Arrhythmia Risk in Hypertensive Rats - Abstract

    EPA Science Inventory

    Epidemiological studies demonstrate a significant association between arrhythmias and air pollution exposure. Sensitivity to aconitine-induced arrhythmia has been used repeatedly to examine the factors that increase the risk of such cardiac electrical dysfunction. In this study, ...

  20. Ground Motion Characteristics of the 2011 Virginia and 1988 Quebec M5.8 Earthquakes

    NASA Astrophysics Data System (ADS)

    Assatourians, K.; Atkinson, G. M.

    2011-12-01

    The largest two earthquakes in eastern North America (ENA) in the last 50 years are the 2011 Mineral, Virginia and the 1988 Saguenay, Quebec earthquakes, both of moment magnitude (M) 5.8. Both events were relatively well-recorded at regional distances (especially the Virginia earthquake) but have a disappointing lack of instrumental records at distances within 50 km, confounding interpretation of expected near-source motions for moderate-to-large ENA events. At regional distances (200 to 500 km), over frequencies from 0.5 to 10 Hz, the instrumentally-recorded motions from the Virginia and Quebec earthquakes show similar amplitudes and attenuation trends; in both cases the motions agree reasonably well with the trend lines suggested by recent ground-motion prediction equations (GMPEs) such as those of Atkinson and Boore (2011) and Pezeshk et al. (2011). At distances <200 km, limited recorded data suggest that the Virginia event does not have high-frequency motions (5 to 10 Hz) as strong as those seen in the Saguenay earthquake, while low-frequency motions (0.5 to 1 Hz) appear to be larger for the Virginia event than for Saguenay. We can augment our understanding of the relative differences in ground motions and attenuation using intensity data; intensity data have the advantage of being available at close distances where instrumental records are sparse. Intensities for the Virginia event were approximately 1 unit lower than those for Saguenay at close distances (<40 km), but attenuated more slowly with distance. Attenuation differences might be partly due to the different focal depths of the events (6 km for Virginia, 28 km for Saguenay), which may have resulted in Moho-bounce effects being seen in a different distance range. Both events had a mean radius for intensity 3 of about 600 km. The observed mean intensity of 3 at 600 km is in agreement with the intensity GMPE of Atkinson and Wald (2007); at close distances, the Virginia intensities are lower than predicted

  1. Intensity Distribution of the 2011 Mw5.8 Mineral, Virginia, Earthquake

    NASA Astrophysics Data System (ADS)

    Hough, S. E.

    2011-12-01

    The Intensity distribution collected by the USGS ``Did You Feel It?'' Web site for the Mw5.8 Mineral, Virginia, earthquake, is unprecedented in its spatial richness, with over 133,000 responses received during the first week. This data can be used to investigate the nature of wave propagation and site response along the East Coast. The earthquake is further valuable as a calibration event to compare against the intensity distributions of key historical earthquakes. The distribution of intensities is consistent with earlier suggestions that wave propagation is more efficient along the (SW-NE) strike of the prevailing tectonic fabric than across it. Several small earthquakes in New York and Quebec, with magnitudes ranging from 1.8 to 3.4, appear to be remotely triggered earthquakes. I explore the statistical significance of the apparent rate increase at regional distances, but note that the distribution of inferred triggered earthquakes is roughly consistent with stronger shaking towards the northeast. The earliest remote event occurred approximately 9 hours after the mainshock; 15 located events with magnitudes 1.6-3.4 occurred in New York state and Quebec, Canada, within the first 5 days. Considering the distribution of intensities, I calculate modified Mercalli intensity residuals relative to a smooth, azimuthally-isotropic decay curve. The distribution of residuals further provides clear evidence for significant site response, for example along Chesapeake Bay and Delaware Bay, with intensities amplified by as much as two MMI units. Significant amplification is also suggested for parts of Washington DC, east of Capitol Hill. At large distances mainshock shaking was felt at many locations at distances up to 1000 km, and some locations as far as approx 1500 km. The radius of the felt distribution is roughly comparable to that of the 1895 Charleston, MO, earthquake, suggesting comparable magnitudes for the two events. I also consider the intensity distribution of the

  2. Hurricane Irene's Impacts on the Aftershock Sequence of the 2011 Mw5.8 Virginia Earthquake

    NASA Astrophysics Data System (ADS)

    Meng, X.; Peng, Z.; Yang, H.; Allman, S.

    2013-12-01

    Recent studies have shown that typhoon could trigger shallow slow-slip events in Taiwan. However, it is unclear whether such extreme weather events could affect the occurrence of regular earthquakes as well. A good opportunity to test this hypothesis occurred in 2011 when an Mw 5.8 earthquake struck Louisa County, Virginia. This event ruptured a shallow, reverse fault. Roughly 5 days later, hurricane Irene struck the coast of Norfolk, Virginia, which is near the epicentral region of the Virginia mainshock. Because aftershocks listed in the ANSS catalog were incomplete immediately after the main shock, it is very difficult to find the genuine correlation between the seismicity rate changes and hurricane Irene. Hence, we use a recently developed waveform matched filter technique to scan through the continuous seismic data to detect small aftershocks that are previously unidentified. A mixture of 7 temporary stations from the IRIS Ramp deployment and 8 temporary stations deployed by Virginia Tech is used. The temporary stations were set up between 24 to 72 hours following the main shock around its immediate vicinity, which provides us a unique dataset recording the majority aftershock sequence of an intraplate earthquake. We us 80 aftershocks identified by Chapman [2013] as template events and scan through the continuous data from 23 August 2011 through 10 September 2011. So far, we have detected 704 events using a threshold of 12 times the median absolute deviation (MAD), which is ~25 times more than listed in the ANSS catalog. The aftershock rate generally decayed with time as predicted by the Omori's law. A statistically significant increase of seismicity rate is found when hurricane Irene passed by the epicentral region. A possible explanation is that the atmosphere pressure drop unloaded the surface, which brought the reverse faults closer to failure. However, we also identified similar fluctuations of seismicity rate changes at other times. Hence, it is still

  3. New bipolar leads for the study of atrial arrhythmias.

    PubMed Central

    Brenes-Pereira, C

    1997-01-01

    The electrocardiography study of atrial arrhythmias has been hindered by the frequent occurrence of a "hidden". P wave in standard lead recordings. We present a modified method of surface electrocardiography that proved helpful in our prospective study of 26 consecutive patients in whom traditional surface recordings did not show the atrial mechanism. We recorded leads I, II, and III in their customary positions, except that we repositioned a pertinent limb electrode at a precordial site, in order to identify a P wave. The 4 alternative sites that we found most helpful were at the high and low parasternal positions, both to the right and to the left of the sternum. Confirmatory examples are submitted. PMID:9205986

  4. Defects in Cytoskeletal Signaling Pathways, Arrhythmia, and Sudden Cardiac Death

    PubMed Central

    Smith, Sakima; Curran, Jerry; Hund, Thomas J.; Mohler, Peter J.

    2012-01-01

    Ankyrin polypeptides are cellular adapter proteins that tether integral membrane proteins to the cytoskeleton in a host of human organs. Initially identified as integral components of the cytoskeleton in erythrocytes, a recent explosion in ankyrin research has demonstrated that these proteins play prominent roles in cytoskeletal signaling pathways and membrane protein trafficking/regulation in a variety of excitable and non-excitable cells including heart and brain. Importantly, ankyrin research has translated from bench to bedside with the discovery of human gene variants associated with ventricular arrhythmias that alter ankyrin–based pathways. Ankyrin polypeptides have also been found to play an instrumental role in various forms of sinus node disease and atrial fibrillation (AF). Mouse models of ankyrin-deficiency have played fundamental roles in the translation of ankyrin-based research to new clinical understanding of human sinus node disease, AF, and ventricular tachycardia. PMID:22586405

  5. A Case for Pharmacogenomics in Management of Cardiac Arrhythmias

    PubMed Central

    Kandoi, Gaurav; Nanda, Anjali; Scaria, Vinod; Sivasubbu, Sridhar

    2012-01-01

    Disorders of the cardiac rhythm are quite prevalent in clinical practice. Though the variability in drug response between individuals has been extensively studied, this information has not been widely used in clinical practice. Rapid advances in the field of pharmacogenomics have provided us with crucial insights on inter-individual genetic variability and its impact on drug metabolism and action. Technologies for faster and cheaper genetic testing and even personal genome sequencing would enable clinicians to optimize prescription based on the genetic makeup of the individual, which would open up new avenues in the area of personalized medicine. We have systematically looked at literature evidence on pharmacogenomics markers for anti-arrhythmic agents from the OpenPGx consortium collection and reason the applicability of genetics in the management of arrhythmia. We also discuss potential issues that need to be resolved before personalized pharmacogenomics becomes a reality in regular clinical practice. PMID:22557843

  6. Coregulation of respiratory sinus arrhythmia in adult romantic partners.

    PubMed

    Helm, Jonathan L; Sbarra, David A; Ferrer, Emilio

    2014-06-01

    Questions surrounding physiological interdependence in romantic relationships are gaining increased attention in the research literature. One specific form of interdependence, coregulation, can be defined as the bidirectional linkage of oscillating signals within optimal bounds. Conceptual and theoretical work suggests that physiological coregulation should be instantiated in romantic couples. Although these ideas are appealing, the central tenets of most coregulatory models await empirical evaluation. In the current study, we evaluate the covariation of respiratory sinus arrhythmia (RSA) in 32 romantic couples during a series of laboratory tasks using a cross-lagged panel model. During the tasks, men's and women's RSA were associated with their partners' previous RSA responses, and this pattern was stronger for those couples with higher relationship satisfaction. The findings are discussed in terms of their implications for attachment theory, as well as the association between relationships and health. PMID:24708502

  7. Update: Arrhythmias (V). Paroxysmal supraventricular tachycardias and preexcitation syndromes.

    PubMed

    Almendral, Jesús; Castellanos, Eduardo; Ortiz, Mercedes

    2012-05-01

    Paroxysmal supraventricular tachycardias are fast and usually regular rhythms that require some structure above the bifurcation of the His bundle to be continued. The 3 most common types are atrial tachycardias, atrioventricular nodal reentrant tachycardias, and tachycardias mediated by an accessory pathway. The last two varieties are discussed in the present manuscript. Their prognosis is benign regarding life expectancy but typically they are symptomatic and chronically recurrent, producing a certain disability. They usually occur in people without structural heart disease. Pharmacologic therapy is possible, but given the high efficacy of catheter ablation, these procedures are frequently chosen. Ventricular preexcitation is due to the presence of an accessory pathway, usually atrioventricular. The clinical course can be asymptomatic, generating a characteristic electrocardiographic pattern, produce paroxysmal supraventricular tachycardias, or facilitate other types of arrhythmias. Very rarely, they can cause sudden cardiac death. The treatment of choice for symptomatic patients is catheter ablation of the accessory pathway. The therapeutic attitude towards asymptomatic preexcitation remains controversial. PMID:22459483

  8. Developmental trajectories of respiratory sinus arrhythmia: associations with social responsiveness.

    PubMed

    Patriquin, Michelle A; Lorenzi, Jill; Scarpa, Angela; Bell, Martha Ann

    2014-04-01

    The present longitudinal study examined relations between respiratory sinus arrhythmia (RSA) development and social responsiveness characteristics associated with autism spectrum disorders. Group-based developmental trajectory modeling was used to characterize RSA development patterns in 106 typically developing children across 5, 10, 24, 36, and 48 months of age. A two-group model fit of RSA development was found: a "typically" and "atypically" developing group. The typical group gradually increased in RSA across 5-48 months of age. The atypical group, however, increased in RSA from 5 to 24 months and demonstrated a plateau or "delay" in RSA development from 24 to 48 months. The atypical RSA development group also demonstrated more difficulties in parent-reported social responsiveness at 48 months. The results support current literature that identifies RSA as a marker of social functioning level. PMID:23341170

  9. Developmental trajectories of respiratory sinus arrhythmia: Associations with social responsiveness

    PubMed Central

    Patriquin, Michelle A.; Lorenzi, Jill; Scarpa, Angela; Bell, Martha Ann

    2012-01-01

    The present longitudinal study examined relations between respiratory sinus arrhythmia (RSA) development and social responsiveness characteristics associated with autism spectrum disorders. Group-based developmental trajectory modeling was used to characterize RSA development patterns in 106 typically developing children across 5, 10, 24, 36, and 48 months of age. A two-group model fit of RSA development was found: a “typically” and “atypically” developing group. The typical group gradually increased in RSA across 5–48 months of age. The atypical group, however, increased in RSA from 5–24 months and demonstrated a plateau or “delay” in RSA development from 24–48 months. The atypical RSA development group also demonstrated more difficulties in parent-reported social responsiveness at 48 months. The results support current literature that identifies RSA as a marker of social functioning level. PMID:23341170

  10. Synthetic opioids and arrhythmia risk: a new paradigm?

    PubMed

    Schuller, Joseph L; Krantz, Mori J

    2012-09-01

    The most commonly prescribed class of medications in the United States for chronic severe pain is opioid analgesics. Due to their low cost and widespread availability, the synthetic opioids are popular choices among clinicians and patients. However, there is an increasingly recognized risk of QT prolongation with several drugs in this class, and recently propoxyphene (Darvon) was withdrawn from the market by the Food and Drug Administration (FDA) due to, in part, the risk of QT prolongation and ventricular arrhythmias Updated Epidemiological Review of Propoxyphene Safety. [FDA Alert]. Rockville, MD: U.S. Food and Drug Administration; 2010. Available from: http://www.fda.gov/downloads/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/UCM234383.pdf on 5 May 2012 . PMID:22770657

  11. Ultra-High-Definition Mapping of Atrial Arrhythmias.

    PubMed

    Bun, Sok-Sithikun; Latcu, Decebal Gabriel; Delassi, Tahar; Jamili, Mohammed El; Amoura, Alaa Al; Saoudi, Nadir

    2016-02-25

    The advantages of ultra-high-definition (UHD) mapping are presented in the context of different atrial arrhythmias, whether focal or macroreentrant. Not only are these sophisticated systems time-saving, but they also allow accurate identification of the substrate (scar quantification), as well as a more precise characterization of the critical isthmuses or focal sources of the atrial circuits. UHD mapping may become a standard approach for their curative treatment. This new technology allows automatic acquisition and accurate annotation of the electrograms, without the need for manual correction. Owing to better resolution, critical isthmuses and low-voltage regions of interest may now be successfully targeted without the need for entrainment maneuvers. Finally, the system also allows rapid assessment of the completeness of the lesions once delivered. (Circ J 2016; 80: 579-586). PMID:26853721

  12. Spectral analysis of sinus arrhythmia - A measure of mental effort

    NASA Technical Reports Server (NTRS)

    Vicente, Kim J.; Craig Thornton, D.; Moray, Neville

    1987-01-01

    The validity of the spectral analysis of sinus arrhythmia as a measure of mental effort was investigated using a computer simulation of a hovercraft piloted along a river as the experimental task. Strong correlation was observed between the subjective effort-ratings and the heart-rate variability (HRV) power spectrum between 0.06 and 0.14 Hz. Significant correlations were observed not only between subjects but, more importantly, within subjects as well, indicating that the spectral analysis of HRV is an accurate measure of the amount of effort being invested by a subject. Results also indicate that the intensity of effort invested by subjects cannot be inferred from the objective ratings of task difficulty or from performance.

  13. Respiratory sinus arrhythmia and cognitive functioning in children.

    PubMed

    Staton, Lori; El-Sheikh, Mona; Buckhalt, Joseph A

    2009-04-01

    We examined associations between children's cognitive performance and both basal respiratory sinus arrhythmia (RSA) and RSA regulation to a reaction time task. Cognitive performance was examined in the lab via standardized tests of cognitive functioning (Woodcock-Johnson III) and a reaction time task. Results suggest that a higher level of basal RSA is predictive of better performance on WJ III scales examining fluid intelligence (e.g., working memory, cognitive efficiency). RSA reactivity was not significantly related to cognitive performance. Results build on and extend the literature by demonstrating that, in typically developing elementary school age children, RSA is related to well-standardized measures of cognitive performance even after controlling for potential confounds. PMID:19107730

  14. [Research progress of quantitative analysis for respiratory sinus arrhythmia].

    PubMed

    Sun, Congcong; Zhang, Zhengbo; Wang, Buqing; Liu, Hongyun; Ang, Qing; Wang, Weidong

    2011-12-01

    Respiratory sinus arrhythmia (RSA) is known as fluctuations of heart rate associated with breathing. It has been increasingly used as a noninvasive index of cardiac vagal tone in psychophysiological research recently. Its analysis is often influenced or distorted by respiratory parameters, posture and action, etc. This paper reviews five methods of quantification, including the root mean square of successive differences (RMSSD), peak valley RSA (pvRSA), cosinor fitting, spectral analysis, and joint timing-frequency analysis (JTFA). Paced breathing, analysis of covariance, residua method and msRSA per liter tidal volume are adjustment strategies of measurement and analysis of RSA in this article as well. At last, some prospects of solutions of the problems of RSA research are given. PMID:22295719

  15. Biomechanical forces exert anabolic effects on osteoblasts by activation of SMAD 1/5/8 through type 1 BMP receptor

    PubMed Central

    Rath, B.; Nam, J.; Deschner, J.; Schaumburger, J.; Tingart, M.; Grässel, S.; Grifka, J.; Agarwal, S.

    2016-01-01

    Osteoblasts are mechanosensitive cells, which respond to biomechanical stimuli to regulate the bone structure through anabolic and catabolic gene regulation. To examine the effects of mechanical forces on the osteogenic responses through the SMAD signaling in osteoblasts, the cells were cultured in well-characterized mechanoresponsive 3-D scaffolds and exposed to 10% dynamic compressive strain (Cmp) at 1 Hz. Subsequently, SMAD phosphorylation and osteogenic gene induction was examined. Osteoblasts cultured in 3-D scaffolds exhibited increased constitutive SMAD 1/5/8 phosphorylation, as compared to monolayers cultures. This SMAD 1/5/8 phosphorylation was further upregulated after 10, 30 and 60 min in response to Cmp, exhibiting a peak activation at 30 min. No significant changes in SMAD2 phosphorylation were observed, suggesting signals generated by Cmp may not activate the Transforming Growth Factor-β signaling cascade. Subsequently, biomechanical stimulation-induced SMAD 1/5/8 phosphorylation upregulated the expression of osteogenic genes such as Osteoprotegrin, Msx2 and Runx2. Dorsomorphin, a selective inhibitor of the bone morphogenetic protein (BMP) receptor type 1 (BMPR1), blocked Cmp-induced SMAD 1/5/8 phosphorylation, as well as Osteoprotegrin, Msx2 and Runx2 gene expression. Collectively, the present findings demonstrate that biomechanical stimulation of osteoblasts activates SMAD 1/5/8 in the BMP signaling pathway through BMPR1 and may enhance osteogenesis by upregulating SMAD-dependent osteogenic genes. PMID:21515935

  16. Outcomes after nonemergent electrical cardioversion for atrial arrhythmias.

    PubMed

    Steinberg, Benjamin Adam; Schulte, Phillip Joel; Hofmann, Paul; Ersbøll, Mads; Alexander, John Hunter; Broderick-Forsgren, Kathleen; Anstrom, Kevin Joseph; Granger, Christopher Bull; Piccini, Jonathan Paul; Velazquez, Eric Jose; Shah, Bimal Ramesh

    2015-05-15

    Electrical cardioversion (ECV) is recommended for rhythm control in patients with atrial arrhythmia; yet, ECV use and outcomes in contemporary practice are unknown. We reviewed all nonemergent ECVs for atrial arrhythmias at a tertiary care center (2010 to 2013), stratifying patients by transesophageal echocardiography (TEE) use before ECV and comparing demographics, history, vitals, and laboratory studies. Outcomes included postprocedural success and complications and repeat cardioversion, rehospitalization, and death within 30 days. Overall, 1,017 patients underwent ECV, 760 (75%) for atrial fibrillation and 240 (24%) for atrial flutter; 633 underwent TEE before ECV and 384 did not. TEE recipients were more likely to be inpatients (74% vs 44%, p <0.001), have higher mean CHADS2 scores (2.6 vs 2.4, p = 0.03), and lower mean international normalized ratios (1.2 vs 2.1, p <0.001). Overall, 89 patients (8.8%) did not achieve sinus rhythm and 14 experienced procedural complications (1.4%). Within 30 days, 80 patients (7.9%) underwent repeat ECV, 113 (11%) were rehospitalized, and 14 (1.4%) died. Although ECV success was more common in patients who underwent TEE before ECV (77% vs 68%, p = 0.01), there were no differences in 30-day death or rehospitalization rates (11.1% vs 13.0%, p = 0.37). In multivariate analyses, higher pre-ECV heart rate was associated with increased rehospitalization or death (adjusted hazard ratio 1.15/10 beats/min, 95% confidence interval 1.07 to 1.24, p <0.001), whereas TEE use was associated with lower rates (adjusted hazard ratio 0.58, 95% confidence interval 0.39 to 0.86, p = 0.007). In conclusion, failures, complications, and rehospitalization after nonemergent ECV are common and associated more with patient condition than procedural characteristics. TEE use was associated with better clinical outcomes. PMID:25784514

  17. Novel Calmodulin (CALM2) Mutations Associated with Congenital Arrhythmia Susceptibility

    PubMed Central

    Makita, Naomasa; Yagihara, Nobue; Crotti, Lia; Johnson, Christopher N.; Beckmann, Britt-Maria; Roh, Michelle S.; Shigemizu, Daichi; Lichtner, Peter; Ishikawa, Taisuke; Aiba, Takeshi; Homfray, Tessa; Behr, Elijah R.; Klug, Didier; Denjoy, Isabelle; Mastantuono, Elisa; Theisen, Daniel; Tsunoda, Tatsuhiko; Satake, Wataru; Toda, Tatsushi; Nakagawa, Hidewaki; Tsuji, Yukiomi; Tsuchiya, Takeshi; Yamamoto, Hirokazu; Miyamoto, Yoshihiro; Endo, Naoto; Kimura, Akinori; Ozaki, Kouichi; Motomura, Hideki; Suda, Kenji; Tanaka, Toshihiro; Schwartz, Peter J.; Meitinger, Thomas; Kääb, Stefan; Guicheney, Pascale; Shimizu, Wataru; Bhuiyan, Zahurul A.; Watanabe, Hiroshi; Chazin, Walter J.; George, Alfred L.

    2014-01-01

    Background Genetic predisposition to life-threatening cardiac arrhythmias such as in congenital long-QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT) represent treatable causes of sudden cardiac death in young adults and children. Recently, mutations in calmodulin (CALM1, CALM2) have been associated with severe forms of LQTS and CPVT, with life-threatening arrhythmias occurring very early in life. Additional mutation-positive cases are needed to discern genotype-phenotype correlations associated with calmodulin mutations. Methods and Results We employed conventional and next-generation sequencing approaches including exome analysis in genotype-negative LQTS probands. We identified five novel de novo missense mutations in CALM2 in three subjects with LQTS (p.N98S, p.N98I, p.D134H) and two subjects with clinical features of both LQTS and CPVT (p.D132E, p.Q136P). Age of onset of major symptoms (syncope or cardiac arrest) ranged from 1–9 years. Three of five probands had cardiac arrest and one of these subjects did not survive. Although all probands had LQTS, two subjects also exhibited electrocardiographic features consistent with CPVT. The clinical severity among subjects in this series was generally less than that originally reported for CALM1 and CALM2 associated with recurrent cardiac arrest during infancy. Four of five probands responded to β-blocker therapy whereas one subject with mutation p.Q136P died suddenly during exertion despite this treatment. Mutations affect conserved residues located within calcium binding loops III (p.N98S, p.N98I) or IV (p.D132E, p.D134H, p.Q136P) and caused reduced calcium binding affinity. Conclusions CALM2 mutations can be associated with LQTS and with overlapping features of LQTS and CPVT. PMID:24917665

  18. Clinical observations of supraventricular arrhythmias in patients with brugada syndrome

    PubMed Central

    Liu, Bing; Guo, Chengjun; Fang, Dongping; Guo, Jinping

    2015-01-01

    Objective: To study various types of supraventricular arrhythmias in patients with Brugada Syndrome. Methods: Forty six patients with ECG of spontaneous type Brugada and with ventricular and/or supraventricular tachyarrhythmia, without structural heart diseases which were excluded by echocardiography, underwent 24 h-Holter recording, electrophysiological study and/or radiofrequency ablation. Results: There were thirty-nine male and seven female (mean age 37.44 years) among total forty-six patients. Twenty one patients had family histories of tachycardia, twentythree patients experienced episodes of syncope, and three patients were resuscitated from cardiac arrest. One patient had ventricular fibrillation and third degree atrioventricular block, eleven patients had polymorphic ventricular tachycardia and five patients had monomorphic ventricular tachycardia. Fourteen patients had atrial tachyarrhythmia, paroxysmal supraventricular tachycardia was found in five patients including four Wolf-Parkinson-White syndrome, two patients hadventricular tachycardia and third degree atrioventricular block, one of them had atrial fibrillation, two patients had both supraventricular tachycardia and ventricular tachycardia, three patients had both atrial tachyarrhythmia and supraventricular tachycardia, two third degree atrioventricular block patients had atrial flutter, one patienthad both atrial tachyrhythmia and ventricular tachycardia. Radiofrequency blation was performed in thirty-nine patients and succeed in thirty-two, four patients were implanted with pacemakers, and four patients had implantable cardioverter defibrillators. Conclusion: In addition to ventricular tachycardia and ventricular fibrillation, patients with Brugada syndrome exhibit various supraventricular tachyarrhythmia and third degree atrioventricular block. In patients with Brugada syndrome, the dysfunction of the cardiac ion channel, which related to mutation of cardiac sodium channelgene, is not limited in

  19. Arrhythmia causes lipid accumulation and reduced glucose uptake.

    PubMed

    Lenski, Matthias; Schleider, Gregor; Kohlhaas, Michael; Adrian, Lucas; Adam, Oliver; Tian, Qinghai; Kaestner, Lars; Lipp, Peter; Lehrke, Michael; Maack, Christoph; Böhm, Michael; Laufs, Ulrich

    2015-01-01

    Atrial fibrillation (AF) is characterized by irregular contractions of atrial cardiomyocytes and increased energy demand. The aim of this study was to characterize the influence of arrhythmia on glucose and fatty acid (FA) metabolism in cardiomyocytes, mice and human left atrial myocardium. Compared to regular pacing, irregular (pseudo-random variation at the same number of contractions/min) pacing of neonatal rat cardiomyocytes induced shorter action potential durations and effective refractory periods and increased diastolic [Ca(2+)]c. This was associated with the activation of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and AMP-activated protein kinase (AMPK). Membrane expression of fatty acid translocase (FAT/CD36) and (14)C-palmitic acid uptake were augmented while membrane expression of glucose transporter subtype 4 (GLUT-4) as well as (3)H-glucose uptake were reduced. Inhibition of AMPK and CaMKII prevented these arrhythmia-induced metabolic changes. Similar alterations of FA metabolism were observed in a transgenic mouse model (RacET) for spontaneous AF. Consistent with these findings samples of left atrial myocardium of patients with AF compared to matched samples of patients with sinus rhythm showed up-regulation of CaMKII and AMPK and increased membrane expression of FAT/CD36, resulting in lipid accumulation. These changes of FA metabolism were accompanied by decreased membrane expression of GLUT-4, increased glycogen content and increased expression of the pro-apoptotic protein bax. Irregular pacing of cardiomyocytes increases diastolic [Ca(2+)]c and activation of CaMKII and AMPK resulting in lipid accumulation, reduced glucose uptake and increased glycogen synthesis. These metabolic changes are accompanied by an activation of pro-apoptotic signalling pathways. PMID:26018791

  20. Role of ATP-sensitive K+ channels in cardiac arrhythmias.

    PubMed

    Nakaya, Haruaki

    2014-05-01

    The sarcolemmal adenosine triphosphate (ATP)-sensitive K(+) (sarcKATP) channel in the heart is a hetero-octamer comprising the pore-forming subunit Kir6.2 and the regulatory subunit sulfonylurea receptor SUR2A. By functional analysis of genetically engineered mice lacking sarcKATP channels, the pathophysiological roles of the K(+) channel in the heart have been extensively evaluated. Although mitochondrial KATP (mitoKATP) channel is proposed to be an important effector for the protection of ischemic myocardium and the inhibition of ischemia/reperfusion-induced ventricular arrhythmias, the molecular identity of mitoKATP channel has not been established. Although selective sarcKATP-channel blockers can prevent ischemia/reperfusion-induced ventricular arrhythmias by inhibiting the action potential shortening in the acute phase, the drugs may aggravate the ischemic damages due to intracellular Ca(2+) overload. The sarcKATP channel is also mandatory for optimal adaptation to hemodynamic stress such as sympathetic activation. Dysfunction of mutated sarcKATP channels in atrial cells may lead to electrical instability and atrial fibrillation. Recently, it has been proposed that the gain-of-function mutation of cardiac Kir6.1 channel can be a pathogenic substrate for J wave syndromes, a cause of idiopathic ventricular fibrillation as early repolarization syndrome or Brugada syndrome, whereas loss of function of the channel mutations can underlie sudden infant death syndrome. However, precise role of Kir6.1 channels in cardiac cells remains to be defined and further study may be needed to clarify the role of Kir6.1 channel in the heart. PMID:24367007

  1. Outcomes Following Non-Emergent Electrical Cardioversion for Atrial Arrhythmias

    PubMed Central

    Steinberg, Benjamin Adam; Schulte, Phillip; Hofmann, Paul; Ersbøll, Mads; Alexander, John Hunter; Broderick-Forsgren, Kathleen; Anstrom, Kevin Joseph; Granger, Christopher Bull; Piccini, Jonathan Paul; Velazquez, Eric Jose; Shah, Bimal Ramesh

    2015-01-01

    Electrical cardioversion (ECV) is recommended for rhythm control in atrial arrhythmia patients, yet ECV use and outcomes in contemporary practice are unknown. We reviewed all non-emergent ECVs for atrial arrhythmias at a tertiary care center (2010–2013), stratifying patients by transesophageal echocardiography (TEE) use pre-ECV and comparing demographics, history, vitals, and laboratory studies. Outcomes included post-procedure success and complications, and repeat cardioversion, rehospitalization, and death within 30 days. Overall, 1017 patients underwent ECV; 760 (75%) for atrial fibrillation and 240 (24%) for atrial flutter; 633 underwent TEE pre-ECV and 384 did not. TEE recipients were more likely to be inpatients (74% vs. 44%, p<0.001), have higher mean CHADS2 scores (2.6 vs. 2.4, p=0.03), and lower mean international normalized ratios (1.2 vs. 2.1, p<0.001). Overall, 89 (8.8%) did not achieve sinus rhythm and 14 experienced procedural complications (1.4%). Within 30 days, 80 (7.9%) underwent repeat ECV, 113 (11%) were rehospitalized, and 14 (1.4%) died. Although ECV success was more common in patients who underwent TEE pre-ECV (77% vs. 68%, p=0.01), there were no differences in 30-day death or rehospitalization rates (11.1% vs. 13.0%, p=0.37). In multivariable analyses, higher pre-ECV heart rate was associated with increased rehospitalization or death (adjusted HR 1.15/10 bpm, 95% CI 1.07–1.24, p<0.001), while TEE use was associated with lower rates (adjusted HR 0.58, 95% CI 0.39–0.86, p=0.007). In conclusion, failures, complications, and rehospitalization following non-emergent ECV are common, and associated more with patient condition than procedural characteristics. TEE use was associated with better clinical outcomes. PMID:25784514

  2. Design of 4x1 microstrip patch antenna array for 5.8 GHz ISM band applications

    NASA Astrophysics Data System (ADS)

    Valjibhai, Gohil Jayesh; Bhatia, Deepak

    2013-01-01

    This paper describes the new design of four element antenna array using corporate feed technique. The proposed antenna array is developed on the Rogers 5880 dielectric material. The antenna array works on 5.8 GHz ISM band. The industrial, scientific and medical (ISM) radio bands are radio bands (portions of the radio spectrum) reserved internationally for the use of radio frequency (RF) energy for industrial, scientific and medical purposes other than communications. The array antennas have VSWR < 1.6 from 5.725 - 5.875 GHz. The simulated return loss characteristic of the antenna array is - 39.3 dB at 5.8 GHz. The gain of the antenna array is 12.3 dB achieved. The directivity of the broadside radiation pattern is 12.7 dBi at the 5.8 GHz operating frequency. The antenna array is simulated using High frequency structure simulation software.

  3. Modification of molecular sieves MCM-41 and SBA-15 with covalently grafted pyromellitimide and 1,4,5,8-naphthalenediimide.

    PubMed

    Trindade, Fabiane Jesus; Rey, José Fernando Queiruga; Brochsztain, Sergio

    2012-02-15

    This article describes the covalent grafting of pyromellitimide and 1,4,5,8-naphthalenediimide, which are organic semiconductors with very interesting electro-optical properties, onto the walls of mesoporous molecular sieves. The mesoporous materials MCM-41 and SBA-15 were first treated with 3-aminopropyltriethoxysilane, generating materials with a surface coverage of primary amino groups. These materials were further reacted with either pyromellitic dianhydride or 1,4,5,8-naphthalenetetracarboxylic dianhydride, generating surface-bound pyromellitimide or 1,4,5,8-naphthalenediimide, respectively. The success of the modification reactions was confirmed by elemental and thermogravimetric analyses, X-ray diffraction patterns and infrared, reflectance and fluorescence spectroscopies. The results indicated that the mesoporous structure of the new materials was preserved after the modification reactions and that the chromophores were included inside the mesoporous channels with stacked aromatic rings. PMID:22153336

  4. Prevention of reoxygenation-induced arrhythmias in guinea pig papillary muscles.

    PubMed

    Hayashi, H; Terada, H; Katoh, H; McDonald, T F

    1996-06-01

    Effects of various agents on reoxygenation-induced arrhythmias, action potentials, and tension of guinea pig papillary muscles were recorded to investigate the site of action. Triggered activities due to delayed afterdepolarizations (DADs) and aftercontractions were elicited on reoxygenation after 60-min substrate-free hypoxia. Low extracellular Ca2+ (0.1 mM) abolished arrhythmias, and high Ca2+ (4.9 mM) increased the amplitudes of DADs and aftercontractions. D-600 at the high concentration (20 microM) decreased the incidence of arrhythmias (p < 0.05 vs. no drug) and decreased the recovery of developed tension after reoxygenation (p < 0.001). Ryanodine (1 microM) abolished aftercontractions and arrhythmias but did not affect the recovery of developed tension. Tetrodotoxin (TTX 3 microM) and nicorandil (100 microM) decreased the incidence of arrhythmias (p < 0.05), but did not affect the recovery of developed tension or the amplitudes of aftercontractions. TTX caused only a slight decrease in Ca2+ transients in a fluo-3-loaded guinea pig ventricular myocyte. The Ca2+ entry through the Ca2+ channels apparently synchronized Ca2+ release from the sarcoplasmic reticulum, and D-600 at the high concentration apparently decreased the incidence of arrhythmias. TTX and nicorandil decreased arrhythmias, probably by decreasing the Na+ current or by increasing the ATP-sensitive K+ current, respectively. PMID:8761848

  5. Proton Pump Inhibitor Use Is not Associated with Cardiac Arrhythmia in Critically Ill Patients

    PubMed Central

    Chen, Kenneth P.; Lee, Joon; Mark, Roger G.; Feng, Mornin; Celi, Leo A.; Danziger, John

    2016-01-01

    Hypomagnesemia can lead to cardiac arrhythmias. Recently, observational data has linked chronic proton pump inhibitor (PPI) exposure to hypomagnesemia. Whether PPI exposure increases the risk for arrhythmias has not been well studied. Using a large, single center inception cohort of critically ill patients, we examined whether PPI exposure was associated with admission electrocardiogram (ECG) readings of a cardiac arrhythmia in over 8000 patients. There were 24.5% PPI users while 6% were taking a histamine 2 antagonist. 14.3% had a cardiac arrhythmia. PPI use was associated with a 1.18 (95% CI=1.02–1.36, p=0.02) unadjusted and 0.96 (95% CI=0.83–1.12, p=0.62) adjusted risk of arrhythmia. Amongst diuretic users (n=2468), PPI use was similarly not associated with an increased risk of cardiac arrhythmia. In summary, in a large cohort of critically ill patients, PPI exposure is not associated with an increased risk of cardiac arrhythmia. PMID:25655574

  6. Exercise-induced ventricular arrhythmias in congestive heart failure and role of ACE inhibitors.

    PubMed

    Hasija, P K; Karloopia, S D; Shahi, B N; Chauhan, S S

    1998-02-01

    Ventricular arrhythmias are considered to be related to left ventricular (LV) dysfunction. ACE inhibitors though improve LV function their beneficial role on exercise-induced ventricular arrhythmias is not established. To study the effects of ACE inhibitors on exercise capacity vis-a-vis their role on exercise-induced ventricular arrhythmias, 25 patients of congestive heart failure (CHF) of various etiologies in NYHA Class II and III were subjected to a prospective randomised controlled trial. The control group comprising of 12 patients received conventional treatment (digitalis and diuretics) and the test group was given enalapril/captopril in addition as tolerated. They were followed up for 3 months. Exercise testing on treadmill and monitoring of clinical and biochemical parameters were done at the beginning and end of study in all cases. Ventricular arrhythmias observed during exercise and post-exercise for 10 minutes was analysed using Lown's grading for frequency and severity of ventricular arrhythmia. The mean exercise duration showed significant improvement on ACE inhibitor as compared to the control group (p < 0.05) however there was no significant change in the grades of arrhythmia. Serum electrolytes and other bio-chemical parameter were within normal range. It is concluded that effect of ACE inhibitor on improving functional capacity in CHF is independent of it's any effect on exercise-induced ventricular arrhythmias. PMID:11273109

  7. Process for manufacturing bis(2-methoxyethyl)-2,3,6,7-tetracyano-1,4,5,8,9,10-hexazaanthracene

    SciTech Connect

    Rasmussen, Paul George; Lawton, Richard Graham

    2014-06-03

    A process to manufacture substituted tetracyano-hexaazatricyclics with the substitutions occurring at the 9 and 10 hydrogens. The process begins with 2,3-dichloro-5,6-dicyanopyrazine, which is reacted to form the desired tetracyano-hexaazatricyclic. Different process embodiments enable different reaction paths to the desired tetracyano-hexaazatricyclic. Different tetracyano-hexaazatricyclic embodiments include bis(2-methoxyethyl)-2,3,6,7-tetracyano-1,4,5,8,9,10-hexazaanthracene and bis(2-methoxyethoxyethyl)-2,3,6,7-tetracyano-1,4,5,8,9,10-hexazaanthracen- e.

  8. Proposition of novel classification approach and features for improved real-time arrhythmia monitoring.

    PubMed

    Kim, Yoon Jae; Heo, Jeong; Park, Kwang Suk; Kim, Sungwan

    2016-08-01

    Arrhythmia refers to a group of conditions in which the heartbeat is irregular, fast, or slow due to abnormal electrical activity in the heart. Some types of arrhythmia such as ventricular fibrillation may result in cardiac arrest or death. Thus, arrhythmia detection becomes an important issue, and various studies have been conducted. Additionally, an arrhythmia detection algorithm for portable devices such as mobile phones has recently been developed because of increasing interest in e-health care. This paper proposes a novel classification approach and features, which are validated for improved real-time arrhythmia monitoring. The classification approach that was employed for arrhythmia detection is based on the concept of ensemble learning and the Taguchi method and has the advantage of being accurate and computationally efficient. The electrocardiography (ECG) data for arrhythmia detection was obtained from the MIT-BIH Arrhythmia Database (n=48). A novel feature, namely the heart rate variability calculated from 5s segments of ECG, which was not considered previously, was used. The novel classification approach and feature demonstrated arrhythmia detection accuracy of 89.13%. When the same data was classified using the conventional support vector machine (SVM), the obtained accuracy was 91.69%, 88.14%, and 88.74% for Gaussian, linear, and polynomial kernels, respectively. In terms of computation time, the proposed classifier was 5821.7 times faster than conventional SVM. In conclusion, the proposed classifier and feature showed performance comparable to those of previous studies, while the computational complexity and update interval were highly reduced. PMID:27318329

  9. Ventricular Arrhythmias in Apparently Normal Hearts: Who Needs an Implantable Cardiac Defibrillator?

    PubMed

    Tan, Alex Y; Ellenbogen, Kenneth

    2016-09-01

    Idiopathic ventricular tachycardia is often considered a benign form of ventricular arrhythmia in patients without apparent structural heart disease. However, a subset of patients may develop malignant ventricular arrhythmias and present with syncope and sudden cardiac arrest. Survivors of cardiac arrest are candidates for implantable cardiac defibrillators (ICDs). The indications for ICDs in patients with less than a full-blown cardiac arrest presentation but with electrocardiographically high-risk ectopy features remain uncertain. This article addresses some of the uncertainties and pitfalls in ICD risk stratification in this patient group and explores potential mechanisms for malignant conversion of benign premature ventricular complexes to sustained arrhythmia. PMID:27521094

  10. HeartSearcher: finds patients with similar arrhythmias based on heartbeat classification.

    PubMed

    Park, Juyoung; Kang, Kyungtae

    2015-12-01

    Long-term electrocardiogram data can be acquired by linking a Holter monitor to a mobile phone. However, most systems of this variety are simply designed to detect arrhythmia through heartbeat classification, and do not provide any additional support for clinical decisions. HeartSearcher identifies patients with similar arrhythmias from heartbeat classifications, by summarising each patient's typical heartbeat pattern in the form of a regular expression, and then ranking patients according to the similarities of their patterns. Results obtained using electrocardiogram data from the MIT-BIH arrhythmia database show that this abstraction reduces the volume of heartbeat classifications by 98% on average, offering great potential to support clinical decisions. PMID:26577165

  11. Clinical management of arrhythmias in elderly patients: results of the European Heart Rhythm Association survey.

    PubMed

    Chen, Jian; Hocini, Mélèze; Larsen, Torben Bjerregaard; Proclemer, Alessandro; Sciaraffia, Elena; Blomström-Lundqvist, Carina

    2015-02-01

    The purpose of this survey was to assess clinical practice in management of cardiac arrhythmias in elderly patients (age ≥75 years) in the European countries. The data are based on an electronic questionnaire sent to the European Heart Rhythm Association Research Network members. Responses were received from 50 centres in 20 countries. The results of the survey have shown that management of cardiac arrhythmias is generally in accordance with the guidelines and consensus recommendations on management of cardiac arrhythmias, although there are some areas of variation, especially on age limit and exclusion of elderly patients for anticoagulation, ablation, and device therapy. PMID:25634939

  12. Non-invasive cardiac mapping in clinical practice: Application to the ablation of cardiac arrhythmias.

    PubMed

    Dubois, Rémi; Shah, Ashok J; Hocini, Mélèze; Denis, Arnaud; Derval, Nicolas; Cochet, Hubert; Sacher, Frédéric; Bear, Laura; Duchateau, Josselin; Jais, Pierre; Haissaguerre, Michel

    2015-01-01

    Ten years ago, electrocardiographic imaging (ECGI) started to demonstrate its efficiency in clinical settings. The initial application to localize focal ventricular arrhythmias such as ventricular premature beats was probably the easiest to challenge and validates the concept. Our clinical experience in using this non-invasive mapping technique to identify the sources of electrical disorders and guide catheter ablation of atrial arrhythmias (premature atrial beat, atrial tachycardia, atrial fibrillation), ventricular arrhythmias (premature ventricular beats) and ventricular pre-excitation (Wolff-Parkinson-White syndrome) is described here. PMID:26403066

  13. The electrocardiogram in the assessment of the effect of drugs on cardiac arrhythmias.

    PubMed Central

    Reid, D S

    1978-01-01

    The search for the ideal antiarrhythmic drug continues since none of the available agents offers optimum antiarrhythmic therapy. The continuing search coupled with the interest in the mechanisms of cardiac arrhythmias has led to the development of new techniques for the study of arrhythmias and antiarrhythmic drugs. In this article it is proposed to discuss the electrocardiographic methods used in the assessment of antiarrhythmic drugs. Firstly, to discuss the electrocardiogram in the assessment of the clinical electrophysiological properties of a drug and secondly, the electrocardiogram in the assessment of the value of the drug in the management of cardiac arrhythmias in man. PMID:365208

  14. Spectrum of Ventricular Arrhythmias Arising from Papillary Muscle in the Structurally Normal Heart.

    PubMed

    Naksuk, Niyada; Kapa, Suraj; Asirvatham, Samuel J

    2016-09-01

    Papillary muscle is an endocavitary structure that can give rise to ventricular arrhythmias in a structurally normal heart. Its manifestation is generally benign. The papillary muscle's complex anatomy and the presence of intermixed Purkinje fibers can create a substrate for idiopathic ventricular fibrillation. Although differentiating ventricular arrhythmias originating from the papillary muscle and the fascicles is challenging and not always possible, the distinction may be helpful for planning ablation. The propensity for difficulty with ablation of papillary arrhythmias results in a variable success rate. Improvement in techniques to stabilize the catheter, use of imaging, and methods of energy delivery are required to improve ablation outcomes. PMID:27521089

  15. Educational Continuity of the Migrant Child. Annual Eastern Stream Conference (5th, Atlanta, Georgia, March 5-8, 1974).

    ERIC Educational Resources Information Center

    Georgia State Dept. of Education, Atlanta.

    The Fifth Annual Eastern Stream Conference on Migrant Education met in Atlanta, Georgia, March 5-8, 1974. Conference objectives were to provide information on: teaching techniques; the Migrant Student Record Transfer System (MSRTS); program designs, plans, and communication techniques; the form, scope, nature and purpose of migrant programs;…

  16. Into Adolescence: A Menu for Good Health. A Curriculum for Grades 5-8. Contemporary Health Series.

    ERIC Educational Resources Information Center

    Laing, Susan J.

    This module, oriented toward middle school students in grades 5-8, includes nine lessons designed to help students synthesize nutritional information and use it to improve their health. In lesson 1, students look at factors that influence food choices. Lesson 2 uses creative expression activities to help students learn about the role of nutrients.…

  17. Into Adolescence: Learning about HIV. Curriculum for Grades 5-8. Contemporary Health Series. [Teachers' Guide] Revised Edition. Student Workbook.

    ERIC Educational Resources Information Center

    Post, Jory; McPherson, Carole

    Through a variety of learning strategies, this curriculum guide provides an age-appropriate Acquired Immune Deficiency Syndrome (AIDS) education for students grades 5-8. An introduction incorporates curriculum objectives, classroom environment, teacher responsibilities, time, instructional strategies, parental involvement and support, and…

  18. Competency-Based Adult Education Classroom Management Guide for Adult Basic Education Curriculum (Level II, 5-8).

    ERIC Educational Resources Information Center

    Singer, Elizabeth

    This Competency-Based Adult Basic Education (CBABE) Classroom Management Guide was developed to aid the Adult Basic Education (ABE) facilitator in implementing a model CBABE Level 5-8 curriculum. First, introductory material provides background on the CBABE project at Brevard Community College (Florida) and the rationale for the development of the…

  19. International Guidelines on Sexuality Education and Their Relevance to a Contemporary Curriculum for Children Aged 5-8 Years

    ERIC Educational Resources Information Center

    Goldman, Juliette D. G.

    2013-01-01

    This paper evaluates UNESCO's recommended sexuality educational framework for junior school students aged 5-8 years. It also compares it to an existing state-designed Health and Physical Education curriculum that includes sexual and reproductive health for the same cohort. Based on the universal values of respect and human rights,…

  20. The Study of Success of Individuals with Exceptional Needs in Tennessee Virtual Academy in Grades 5-8

    ERIC Educational Resources Information Center

    Vernon, Nichole

    2013-01-01

    The purpose of this study was to examine the success of students in Exceptional Education in Tennessee Virtual Academy. Students participating in this study are in grades 5-8, have a diagnosis of Specific Learning Disabilities, residents of Tennessee, currently enrolled in Tennessee Virtual Academy, and received Exceptional Education services.…

  1. Source apportionment of PM2.5 at multiple sites in Venice (Italy): Spatial variability and the role of weather

    NASA Astrophysics Data System (ADS)

    Masiol, Mauro; Squizzato, Stefania; Rampazzo, Giancarlo; Pavoni, Bruno

    2014-12-01

    This study investigates the chemical speciation of fine particulate matter (PM2.5) collected at three sites in the Venice area, eastern Po Valley (Italy). This area is one of the few hot spots left in Europe where levels of PM2.5 frequently breach EU target values and cause a serious risk for public health. Elemental composition, inorganic ions and polycyclic aromatic hydrocarbon concentrations were quantified in 448 PM2.5 samples and the multiple-site PMF receptor model was based on the elemental and inorganic ion data. Six factors associated with potential sources were quantified, namely, secondary sulfate, ammonium nitrate and combustions, fossil fuels, traffic, industrial and glassmaking. Source apportionment results were further processed using a series of chemometric tools for returning additional information about the seasonal and spatial changes of factors extracted by the PMF analysis. In addition, PMF results were also studied in combination with weather conditions and PAH concentrations revealing that sources of secondary nitrate and sulfate are homogeneously distributed throughout the area, while remaining pollutant sources may have a distinct origin. PMF results were cluster analyzed to sort out samples with similar source profiles and then the wind roses of grouped samples were examined to assess the role of wind speed and direction on PM2.5 pollution and chemistry. The tested tools and the results obtained can be used for air quality assessment studies and air pollution reduction strategies.

  2. Sediment dynamics in shallow tidal basins: In situ observations, satellite retrievals, and numerical modeling in the Venice Lagoon

    NASA Astrophysics Data System (ADS)

    Carniello, L.; Silvestri, S.; Marani, M.; D'Alpaos, A.; Volpe, V.; Defina, A.

    2014-04-01

    The morphological evolution of shallow tidal systems strongly depends on gradients in transport that control sediment erosion and deposition. A spatially refined quantitative description of suspended sediment patterns and dynamics is therefore a key requirement to address issues connected with dynamical trends, responses, and conservation of these systems. Here we use a combination of numerical models of sediment transport dynamics, high temporal resolution point observations, and high spatial resolution remote sensing data to overcome the intrinsic limitations of traditional monitoring approaches and to establish the robustness of numerical models in reproducing space-time suspended sediment concentration (SSC) patterns. The comparison of SSC distributions in the Venice Lagoon (Italy) computed with a numerical model with SSC retrievals from remote sensing data allows us to define the ability of the model to properly describe spatial patterns and gradients in the SSC fields. The use of point observations similarly allows us to constrain the model temporally, thus leading to a complete space-time evaluation of model abilities. Our results highlight the fundamental control exerted on sediment transport intensity and patterns by the sheltering effect associated with artificial and natural intertidal landforms. Furthermore, we show how the stabilizing effect of benthic vegetation is a main control of sediment dynamics at the system scale, confirming a notion previously established in the laboratory or at small field scales.

  3. Environmental and traffic-related parameters affecting road dust composition: A multi-technique approach applied to Venice area (Italy)

    NASA Astrophysics Data System (ADS)

    Valotto, Gabrio; Rampazzo, Giancarlo; Visin, Flavia; Gonella, Francesco; Cattaruzza, Elti; Glisenti, Antonella; Formenton, Gianni; Tieppo, Paulo

    2015-12-01

    Road dust is a non-exhaust source of atmospheric particulate by re-suspension. It is composed of particles originating from natural sources as well as other non-exhaust source such as tire, brake and asphalt wear. The discrimination between atmospheric particles directly emitted from abrasion process and those related to re-suspension is therefore an open issue, as far as the percentage contribution of non-exhaust emissions is becoming more considerable due also to the recent policy actions and the technological upgrades in the automotive field, focused on the reduction of exhaust emissions. In this paper, road dust collected along the bridge that connects Venice (Italy) to the mainland is characterized with a multi-technique approach in order to determine its composition depending on environmental as well as traffic-related conditions. Six pollutant sources of road dust particles were identified by cluster analysis: brake, railway, tire, asphalt, soil + marine, and mixed combustions. Considering the lack of information on this matrix in this area, this study is intended to provide useful information for future identification of road dust re-suspension source in atmospheric particulate.

  4. Natural Recovery and Planned Intervention in Coastal Wetlands: Venice Lagoon (Northern Adriatic Sea, Italy) as a Case Study

    PubMed Central

    Ceoldo, Sonia; Pellegrino, Nicola

    2014-01-01

    The goals of conservation and sustainable use of environmental ecosystems have increased the need for detailed knowledge of ecological evolution and responses to both anthropogenic pressures and recovery measures. The present study shows the effects of natural processes and planned intervention in terms of reducing nutrient inputs in a highly exploited coastal lagoon, describing its evolution over a 16-year period from the late 1980s (when eutrophication was at its peak) until 2003. Changes in nutrient and carbon concentrations in the top layer of sediments were investigated in parallel with macroalgal and seagrass biomass in the most anthropized basin of Venice Lagoon in four surveys conducted in accordance with the same protocols in 1987, 1993, 1998, and 2003. A pronounced reduction in trophic state (mainly total nitrogen, organic phosphorus, and organic carbon concentrations) and macroalgal biomass was recorded, together with the progressive expansion of seagrass meadows. General considerations are also made on the effects of Manila clam farming and the shift from illegal to managed clam farming. PMID:25126611

  5. Plant-soil interactions in salt marsh environments: Experimental evidence from electrical resistivity tomography in the Venice Lagoon

    NASA Astrophysics Data System (ADS)

    Boaga, Jacopo; D'Alpaos, Andrea; Cassiani, Giorgio; Marani, Marco; Putti, Mario

    2014-09-01

    The role of root water uptake in regulating soil water saturation in salt marshes is controversial. Modeling studies suggest that soil aeration is improved by transpiration, with implications for the distribution of vegetation species and of the associated topographic features controlling the hydraulic regime of the marshland and eventually its survival. Marsh vegetation plays a key role in the preservation of such critical environment, which represents unique marker for climatic change and impact studies. However, the direct quantification of space-time aeration patterns has remained elusive, in part, because of the limitations posed by high salinity to conventional observation techniques such as time or frequency domain reflectometry. Here we show that time-lapse microscale electrical resistivity tomography, coupled with tensiometric observations, allows the identification of variably saturated zones and the characterization of space-time soil moisture dynamics in a salt marsh in the Venice Lagoon (Italy). This is the first quantitative observational experiment which confirms that periodically flooded plants are capable of producing a persistently aerated layer below the flooded surface when transpiration proceeds at a sufficiently high rate. The experimental results are compared against previously published model predictions.

  6. Natural recovery and planned intervention in coastal wetlands: Venice Lagoon (northern Adriatic Sea, Italy) as a case study.

    PubMed

    Facca, Chiara; Ceoldo, Sonia; Pellegrino, Nicola; Sfriso, Adriano

    2014-01-01

    The goals of conservation and sustainable use of environmental ecosystems have increased the need for detailed knowledge of ecological evolution and responses to both anthropogenic pressures and recovery measures. The present study shows the effects of natural processes and planned intervention in terms of reducing nutrient inputs in a highly exploited coastal lagoon, describing its evolution over a 16-year period from the late 1980s (when eutrophication was at its peak) until 2003. Changes in nutrient and carbon concentrations in the top layer of sediments were investigated in parallel with macroalgal and seagrass biomass in the most anthropized basin of Venice Lagoon in four surveys conducted in accordance with the same protocols in 1987, 1993, 1998, and 2003. A pronounced reduction in trophic state (mainly total nitrogen, organic phosphorus, and organic carbon concentrations) and macroalgal biomass was recorded, together with the progressive expansion of seagrass meadows. General considerations are also made on the effects of Manila clam farming and the shift from illegal to managed clam farming. PMID:25126611

  7. From Point Cloud to Digital Fabrication: a Tangible Reconstruction of Ca' Venier Dei Leoni, the Guggenheim Museum in Venice

    NASA Astrophysics Data System (ADS)

    Balletti, C.; D'Agnano, F.; Guerra, F.; Vernier, P.

    2016-06-01

    The paper describes how new digital methodologies can be used within the field of Cultural Heritage, not only with the aim of documenting the actual state of an architecture but to review the past transformations it has undergone, conserving and representing these histories as well. The premise to conservation and enhancement of our Heritage is a deep study in terms of position, shape, colour, and also of the historical and artistic features. Survey methods have acquired data acquisition techniques in line with technological progress: today's electronic and IT technologies, that are the tools of modern Geomatics, allow the effective survey and representation of 3D objects, from architectural structures to sculptures or archaeological finds. Over the last few years, the methodologies of acquisition and integrated representation for 3D patrimony documentation have developed and consolidated considerably: the possibilities of the digital realm can augment the understanding and the valorisation of a monument. The specific case offered in the present paper, Ca' Venier dei Leoni, the palace where is the Guggenheim Museum in Venice, is a significant example. It suggests not only the theme of the "no longer existing", or better never built, but also the opportunity to formulate hypotheses regarding its implementation and the impact that the palace would have had in the Venetian contest.

  8. Saltwater contamination in the managed low-lying farmland of the Venice coast, Italy: An assessment of vulnerability.

    PubMed

    Da Lio, Cristina; Carol, Eleonora; Kruse, Eduardo; Teatini, Pietro; Tosi, Luigi

    2015-11-15

    The original morphology and hydrogeology of many low-lying coastlands worldwide have been significantly modified over the last century through river diversion, embankment built-up, and large-scale land reclamation projects. This led to a progressive shifting of the groundwater-surficial water exchanges from naturally to anthropogenically driven. In this human-influenced hydrologic landscape, the saltwater contamination usually jeopardizes the soil productivity. In the coastland south of Venice (Italy), several well log measurements, chemical and isotope analyses have been performed over the last decade to characterize the occurrence of the salt contamination. The processing of this huge dataset highlights a permanent variously-shaped saline contamination up to 20km inland, with different conditions in relation with the various geomorphological features of the area. The results point out the important role of the land reclamation in shaping the present-day salt contamination and reveal the contribution of precipitation, river discharge, lagoon and sea water to the shallow groundwater in the various coastal sectors. Moreover, an original vulnerability map to salt contamination in relation to the farmland productivity has been developed taking into account the electrical conductivity of the upper aquifer in the worst condition, the ground elevation, and the distance from salt and fresh surface water sources. Finally, the study allows highlighting the limit of traditional investigations in monitoring saltwater contamination at the regional scale in managed Holocene coastal environments. Possible improvements are outlined. PMID:26172603

  9. Biomarkers and trace metals in the digestive gland of indigenous and transplanted mussels, Mytilus galloprovincialis, in Venice Lagoon, Italy.

    PubMed

    Da Ros, L; Nasci, C; Marigomez, I; Soto, M

    2000-01-01

    The aim of this study was to investigate the cellular and biochemical response of mussels, Mytilus galloprovincialis, transplanted from a relatively pristine site to a polluted one and vice versa in the Lagoon of Venice (northeast of Italy) and to apply auto-metallography, a rapid and sensitive histochemical technique, to determine the bio-available fraction of heavy metals accumulated in the body tissues of organisms. Animal digestive glands have been used for morphological analyses (lysosomal volume, surface and numerical density, mean epithelial thickness, mean diverticular and luminar radius), autometallographical black silver deposits quantification and biochemical assays (superoxide dismutase and catalase activity). Furthermore, heavy metal content was determined by atomic absorption spectrophotometry (AAS) using standard procedures. The overall results indicate a direct influence of the environment in the thinning of the digestive cells and in the increasing number of lysosomes in mussels from the more polluted site. These data are in agreement with the metal content in digestive cell lysosomes as determined by autometallography, whereas AAS measurements show less significant differences. PMID:11460729

  10. Microplastic particles in sediments of Lagoon of Venice, Italy: First observations on occurrence, spatial patterns and identification

    NASA Astrophysics Data System (ADS)

    Vianello, A.; Boldrin, A.; Guerriero, P.; Moschino, V.; Rella, R.; Sturaro, A.; Da Ros, L.

    2013-09-01

    In order to improve knowledge of the identification, distribution and abundances of microplastic particles of 1 mm or less (S-MPPs) in the coastal area of the Mediterranean region, a preliminary monitoring survey was carried out in a transitional environment along the north-eastern Italian coasts, the Lagoon of Venice. S-MPPs were evaluated in sediments collected from 10 sites chosen in shallow areas variously affected by natural conditions and anthropogenic influences (i.e., landward stations influenced by freshwater inputs, seaward areas near sea inlets, and sites influenced by the presence of aquaculture farms, industry and city centers). S-MPPs, extracted from bulk sediments by density separation, were counted and identified by Fourier-Transform Infrared Micro-spectroscopy (μFT-IR). The μFT-IR process included automatic surface chemical mapping and references to an infrared library database to identify the compositional spectra of particles. S-MPPs were recovered from all samples - a fact which emphasizes their extensive distribution throughout the Lagoon. Total abundances varied from 2175 to 672 S-MPPs kg-1 d.w., higher concentrations generally being observed in landward sites. Of the ten polymer types identified, the most abundant, accounting for more than 82% of total S-MPPs, were polyethylene and polypropylene. The most frequent size (93% of observed microplastics) was in the range 30-500 μm. Total S-MPP values were significantly correlated with the finer sediment fraction and with the metal pollution index.

  11. Hyperspectral Sensor Data Capability for Retrieving Complex Urban Land Cover in Comparison with Multispectral Data: Venice City Case Study (Italy)

    PubMed Central

    Cavalli, Rosa Maria; Fusilli, Lorenzo; Pascucci, Simone; Pignatti, Stefano; Santini, Federico

    2008-01-01

    This study aims at comparing the capability of different sensors to detect land cover materials within an historical urban center. The main objective is to evaluate the added value of hyperspectral sensors in mapping a complex urban context. In this study we used: (a) the ALI and Hyperion satellite data, (b) the LANDSAT ETM+ satellite data, (c) MIVIS airborne data and (d) the high spatial resolution IKONOS imagery as reference. The Venice city center shows a complex urban land cover and therefore was chosen for testing the spectral and spatial characteristics of different sensors in mapping the urban tissue. For this purpose, an object-oriented approach and different common classification methods were used. Moreover, spectra of the main anthropogenic surfaces (i.e. roofing and paving materials) were collected during the field campaigns conducted on the study area. They were exploited for applying band-depth and sub-pixel analyses to subsets of Hyperion and MIVIS hyperspectral imagery. The results show that satellite data with a 30m spatial resolution (ALI, LANDSAT ETM+ and HYPERION) are able to identify only the main urban land cover materials.

  12. Effect of fish oil on arrhythmias and mortality: systematic review

    PubMed Central

    León, Hernando; Shibata, Marcelo C; Sivakumaran, Soori; Dorgan, Marlene; Chatterley, Trish

    2008-01-01

    Objective To synthesise the literature on the effects of fish oil—docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)—on mortality and arrhythmias and to explore dose response and formulation effects. Design Systematic review and meta-analysis. Data sources Medline, Embase, the Cochrane Library, PubMed, CINAHL, IPA, Web of Science, Scopus, Pascal, Allied and Complementary Medicine, Academic OneFile, ProQuest Dissertations and Theses, Evidence-Based Complementary Medicine, and LILACS. Studies reviewed Randomised controlled trials of fish oil as dietary supplements in humans. Data extraction The primary outcomes of interest were the arrhythmic end points of appropriate implantable cardiac defibrillator intervention and sudden cardiac death. The secondary outcomes were all cause mortality and death from cardiac causes. Subgroup analyses included the effect of formulations of EPA and DHA on death from cardiac causes and effects of fish oil in patients with coronary artery disease or myocardial infarction. Data synthesis 12 studies totalling 32 779 patients met the inclusion criteria. A neutral effect was reported in three studies (n=1148) for appropriate implantable cardiac defibrillator intervention (odds ratio 0.90, 95% confidence interval 0.55 to 1.46) and in six studies (n=31 111) for sudden cardiac death (0.81, 0.52 to 1.25). 11 studies (n=32 439 and n=32 519) provided data on the effects of fish oil on all cause mortality (0.92, 0.82 to 1.03) and a reduction in deaths from cardiac causes (0.80, 0.69 to 0.92). The dose-response relation for DHA and EPA on reduction in deaths from cardiac causes was not significant. Conclusions Fish oil supplementation was associated with a significant reduction in deaths from cardiac causes but had no effect on arrhythmias or all cause mortality. Evidence to recommend an optimal formulation of EPA or DHA to reduce these outcomes is insufficient. Fish oils are a heterogeneous product, and the optimal formulations

  13. Cardiac Sympathetic Nerve Sprouting and Susceptibility to Ventricular Arrhythmias after Myocardial Infarction.

    PubMed

    Li, Chang-Yi; Li, Yi-Gang

    2015-01-01

    Ventricular arrhythmogenesis is thought to be a common cause of sudden cardiac death following myocardial infarction (MI). Nerve remodeling as a result of MI is known to be an important genesis of life-threatening arrhythmias. It is hypothesized that neural modulation might serve as a therapeutic option of malignant arrhythmias. In fact, left stellectomy or β-blocker therapy is shown to be effective in the prevention of ventricular tachyarrhythmias (VT), ventricular fibrillation (VF), and sudden cardiac death (SCD) after MI both in patients and in animal models. Results from decades of research already evidenced a positive relationship between abnormal nerve density and ventricular arrhythmias after MI. In this review, we summarized the molecular mechanisms involved in cardiac sympathetic rejuvenation and mechanisms related to sympathetic hyperinnervation and arrhythmogenesis after MI and analyzed the potential therapeutic implications of nerve sprouting modification for ventricular arrhythmias and SCD control. PMID:26793403

  14. Cardiac Sympathetic Nerve Sprouting and Susceptibility to Ventricular Arrhythmias after Myocardial Infarction

    PubMed Central

    Li, Chang-Yi; Li, Yi-Gang

    2015-01-01

    Ventricular arrhythmogenesis is thought to be a common cause of sudden cardiac death following myocardial infarction (MI). Nerve remodeling as a result of MI is known to be an important genesis of life-threatening arrhythmias. It is hypothesized that neural modulation might serve as a therapeutic option of malignant arrhythmias. In fact, left stellectomy or β-blocker therapy is shown to be effective in the prevention of ventricular tachyarrhythmias (VT), ventricular fibrillation (VF), and sudden cardiac death (SCD) after MI both in patients and in animal models. Results from decades of research already evidenced a positive relationship between abnormal nerve density and ventricular arrhythmias after MI. In this review, we summarized the molecular mechanisms involved in cardiac sympathetic rejuvenation and mechanisms related to sympathetic hyperinnervation and arrhythmogenesis after MI and analyzed the potential therapeutic implications of nerve sprouting modification for ventricular arrhythmias and SCD control. PMID:26793403

  15. Study of features based on nonlinear dynamical modeling in ECG arrhythmia detection and classification.

    PubMed

    Owis, Mohamed I; Abou-Zied, Ahmed H; Youssef, Abou-Bakr M; Kadah, Yasser M

    2002-07-01

    We present a study of the nonlinear dynamics of electrocardiogram (ECG) signals for arrhythmia characterization. The correlation dimension and largest Lyapunov exponent are used to model the chaotic nature of five different classes of ECG signals. The model parameters are evaluated for a large number of real ECG signals within each class and the results are reported. The presented algorithms allow automatic calculation of the features. The statistical analysis of the calculated features indicates that they differ significantly between normal heart rhythm and the different arrhythmia types and, hence, can be rather useful in ECG arrhythmia detection. On the other hand, the results indicate that the discrimination between different arrhythmia types is difficult using such features. The results of this work are supported by statistical analysis that provides a clear outline for the potential uses and limitations of these features. PMID:12083309

  16. Dipyridamole-thallium tests are predictive of severe cardiac arrhythmias in patients with left ventricular hypertrophy

    SciTech Connect

    Saragoca, M.A.; Canziani, M.E.; Gil, M.A.; Castiglioni, M.L.; Cassiolato, J.L.; Barbieri, A.; Lima, V.C.; Draibe, S.A.; Martinez, E.E. )

    1991-01-01

    In a population of patients with chronic renal failure (CRF) and a high prevalence of left ventricular hypertrophy (LVH) undergoing chronic hemodialysis, the authors investigated the association between the results of dipyridamole-thallium tests (DTTs) and the occurrence of ventricular arrhythmias. They observed a positive significant association between positive DTTs and the occurrence of severe forms of ventricular arrhythmias. A significant association was also observed between the presence of severe LVH and the occurrence of severe ventricular arrhythmias. However, no association was found between the presence of LVH and the positivity of the DTT. As most of their patients with positive DTTs had unimpaired coronary circulations, they conclude that positive DTTs, although falsely indicative of impaired myocardial blood supply, does have an important clinical relevance, indicating increased risk of morbidity (and, possibly, mortality) due to ventricular arrhythmias in a population of CRF patients submitted to chronic renal function replacement program.

  17. Getting your signals straight. Comparing radio-frequency ablation and cryoablation for treating cardiac arrhythmias.

    PubMed

    2010-08-01

    Radio-frequency ablation has proven to be an effective method for treating cardiac arrhythmias. However, a newer treatment method called cryoablation is becoming increasingly popular. In this article, we discuss the advantages and disadvantages of each. PMID:21305902

  18. Induced pluripotent stem cell-derived cardiomyocytes: boutique science or valuable arrhythmia model?

    PubMed

    Knollmann, Björn C

    2013-03-15

    This article reviews the strengths and limitations of induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM) as models of cardiac arrhythmias. Specifically, the article attempts to answer the following questions: Which clinical arrhythmias can be modeled by iPSC-CM? How well can iPSC-CM model adult ventricular myocytes? What are the strengths and limitations of published iPSC-CM arrhythmia models? What new mechanistic insight has been gained? What is the evidence that would support using iPSC-CM to personalize antiarrhythmic drug therapy? The review also discusses the pros and cons of using the iPSC-CM technology for modeling specific genetic arrhythmia disorders, such as long QT syndrome, Brugada Syndrome, or Catecholaminergic Polymorphic Ventricular Tachycardia. PMID:23569106

  19. Extracellular photosensitization reaction progress and effect on myocardial cell necrosis for arrhythmia treatment application

    NASA Astrophysics Data System (ADS)

    Ogawa, Emiyu; Takahashi, Mei; Ito, Arisa; Arai, Tsunenori

    2013-06-01

    We investigated detailed extracellular photosensitization reaction effect on rat myocardial cells and the photosensitization reaction progress in a well to study a new application of photodynamic therapy for arrhythmia therapy.

  20. Addition polymers from 1,4,5,8-tetrahydro-1,4;5,8-diepoxyanthracene and Bis-dienes. 2: Evidence for thermal dehydration occurring in the cure process

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B.; Olshavsky, Michael A.; Meador, Michael A.; Ahn, Myong-Ku

    1988-01-01

    Diels-Alder cycloaddition copolymers from 1,4,5,8-tetrahydro-1,4;5,8-diepoxyanthracene and anthracene end-capped polyimide oligomers appear, by thermogravimetric analysis (TGA), to undergo dehydration at elevated temperatures. This would produce thermally stable pentiptycene units along the polymer backbone, and render the polymers incapable of unzipping through a retro-Diels-Alder pathway. High resolution solid 13C nuclear magnetic resonance (NMR) of one formulation of the polymer system before and after heating at elevated temperatures, shows this to indeed be the case. NMR spectra of solid samples of the polymer before and after heating correlated well with those of the parent pentiptycene model compound before and after acid-catalyzed dehydration. Isothermal gravimetric analyses and viscosities of the polymer before and after heat treatment support dehydration as a mechanism for the cure reaction.

  1. Transient myocardial ischaemia after acute myocardial infarction does not induce ventricular arrhythmias.

    PubMed Central

    Currie, P; Saltissi, S

    1993-01-01

    OBJECTIVE--To see whether transient myocardial ischaemia on ambulatory monitoring after myocardial infarction is associated with ventricular arrhythmias. DESIGN--A prospective study. SETTING--The coronary care unit, general medical wards, and cardiorespiratory department of a major teaching hospital. PATIENTS--203 consecutive patients without specific exclusion criteria admitted with acute myocardial infarction. INTERVENTIONS--24 hour ambulatory electrocardiographic monitoring for ventricular arrhythmias and ST depression both early (mean 6.3 days after infarction, n = 201) and late (mean 38 days, n = 177). MAIN OUTCOME MEASURES--Episodes of myocardial ischaemia were identified during ambulatory monitoring by transient ST depression of > or = 1.0 mm lasting for > or = 30 s. Ventricular arrhythmias were single extrasystoles, couplets, or ventricular tachycardia. RESULTS--All ventricular arrhythmias were significantly more frequent in late than early monitoring. The arrhythmias included couplets (in 83/174 (48%) v 49/200 (25%) of patients, p = 0.0000028) and ventricular tachycardia (29/174 (17%) v 15/199 (8%), p = 0.0064). Patients with ST depression (29 early; 56 late), compared with those without ischaemia, did not experience a significant increase in single extrasystoles, couplets (31% v 23% early; 47% v 48% late), or ventricular tachycardia (3% v 8% early; 18% v 16% late). Even patients with frequent (> or = 3 episodes), and deep (> or = 1.5 mm) or prolonged (> or = 20 min) ST depression had no increase in arrhythmias. CONCLUSIONS--Ventricular arrhythmias after myocardial infarction are not associated with transient myocardial ischaemia during daily activities. This study does not support the belief that to abolish silent ischaemia would reduce the incidence of sudden death due to uncontrollable ventricular arrhythmias after myocardial infarction. PMID:8489860

  2. Inhibition of Rac1 reduces store overload-induced calcium release and protects against ventricular arrhythmia.

    PubMed

    Zhang, Lili; Lu, Xiangru; Gui, Le; Wu, Yan; Sims, Stephen M; Wang, Guoping; Feng, Qingping

    2016-08-01

    Rac1 is a small GTPase and plays key roles in multiple cellular processes including the production of reactive oxygen species (ROS). However, whether Rac1 activation during myocardial ischaemia and reperfusion (I/R) contributes to arrhythmogenesis is not fully understood. We aimed to study the effects of Rac1 inhibition on store overload-induced Ca(2+) release (SOICR) and ventricular arrhythmia during myocardial I/R. Adult Rac1(f/f) and cardiac-specific Rac1 knockdown (Rac1(ckd) ) mice were subjected to myocardial I/R and their electrocardiograms (ECGs) were monitored for ventricular arrhythmia. Myocardial Rac1 activity was increased and ventricular arrhythmia was induced during I/R in Rac1(f/f) mice. Remarkably, I/R-induced ventricular arrhythmia was significantly decreased in Rac1(ckd) compared to Rac1(f/f) mice. Furthermore, treatment with Rac1 inhibitor NSC23766 decreased I/R-induced ventricular arrhythmia. Ca(2+) imaging analysis showed that in response to a 6 mM external Ca(2+) concentration challenge, SOICR was induced with characteristic spontaneous intracellular Ca(2+) waves in Rac1(f/f) cardiomyocytes. Notably, SOICR was diminished by pharmacological and genetic inhibition of Rac1 in adult cardiomyocytes. Moreover, I/R-induced ROS production and ryanodine receptor 2 (RyR2) oxidation were significantly inhibited in the myocardium of Rac1(ckd) mice. We conclude that Rac1 activation induces ventricular arrhythmia during myocardial I/R. Inhibition of Rac1 suppresses SOICR and protects against ventricular arrhythmia. Blockade of Rac1 activation may represent a new paradigm for the treatment of cardiac arrhythmia in ischaemic heart disease. PMID:27222313

  3. Cardiac ultrasonography in structural abnormalities and arrhythmias. Recognition and treatment.

    PubMed Central

    Brook, M M; Silverman, N H; Villegas, M

    1993-01-01

    Fetal cardiac ultrasonography has become an important tool in the evaluation of fetuses at risk for cardiac anomalies. It can both guide prenatal treatment and assist the management and timing of delivery. We recommend that a fetal echocardiogram be done when there is a family history of congenital heart disease; maternal disease that may affect the fetus; a history of maternal drug use, either therapeutic or illegal; evidence of other fetal abnormalities; or evidence of fetal hydrops. The optimal timing of evaluation is 18 to 22 weeks' gestation. An entire range of structural cardiac defects can be visualized prenatally, including atrioventricular septal defect, ventricular septal defect, cardiomyopathy, ventricular outlet obstruction, and complex cardiac defects. The outcome for a fetus with a recognized abnormality is unfavourable, with less than 50% surviving the neonatal period. Fetal cardiac arrhythmias are also a common occurrence, 15% in the series described here. Premature atrial or ventricular contractions are most commonly seen and usually require no treatment. Supraventricular tachycardia can result in hydrops and require in utero treatment to prevent fetal demise. Complete heart block, particularly in association with structural heart disease, has a poor prognosis for fetal survival. Images PMID:8236970

  4. [Frequent arrhythmias in Wolff-Parkinson-White syndrome].

    PubMed

    Cárdenas, M

    1990-01-01

    The real knowledge of the natural history in preexcitation syndrome is not possible, Circus movement reciprocal atrioventricular tachycardia is seen en 60% of the patients. Mostly of them are orthodromic. In this group, A-H increases in duration. H-V become normal and the delta wave disappears in the electrophysiologic study during the tachycardia. In the antidromic group, A-delta decreases and H deflexion cannot be recognized. Pre-excitation with atrial flutter is a rare but very dangerous situation when atrial impulses are conducted by the anomalous bundle, because the very high ventricular rate with 250 mseg R-R intervals. The same happens in patients with atrial fibrillation, observed in 5% of the patients with WPW syndrome; this arrhythmia may provoke multiform ventricular tachycardia, ventricular fibrillation and sudden death. Sudden death occurs in 0.1% of asymptomatic patients with WPW in 1% in those with reciprocal tachycardias and in 5.6% of the patients with atrial fibrillation and R-R intervals of 250 mseg of less. PMID:2091550

  5. The Brugada Syndrome: A Rare Arrhythmia Disorder with Complex Inheritance

    PubMed Central

    Gourraud, Jean-Baptiste; Barc, Julien; Thollet, Aurélie; Le Scouarnec, Solena; Le Marec, Hervé; Schott, Jean-Jacques; Redon, Richard; Probst, Vincent

    2016-01-01

    For the last 10 years, applying new sequencing technologies to thousands of whole exomes has revealed the high variability of the human genome. Extreme caution should thus be taken to avoid misinterpretation when associating rare genetic variants to disease susceptibility. The Brugada syndrome (BrS) is a rare inherited arrhythmia disease associated with high risk of sudden cardiac death in the young adult. Familial inheritance has long been described as Mendelian, with autosomal dominant mode of transmission and incomplete penetrance. However, all except 1 of the 23 genes previously associated with the disease have been identified through a candidate gene approach. To date, only rare coding variants in the SCN5A gene have been significantly associated with the syndrome. However, the genotype/phenotype studies conducted in families with SCN5A mutations illustrate the complex mode of inheritance of BrS. This genetic complexity has recently been confirmed by the identification of common polymorphic alleles strongly associated with disease risk. The implication of both rare and common variants in BrS susceptibility implies that one should first define a proper genetic model for BrS predisposition prior to applying molecular diagnosis. Although long remains the way to personalized medicine against BrS, the high phenotype variability encountered in familial forms of the disease may partly find an explanation into this specific genetic architecture. PMID:27200363

  6. Detection of false arrhythmia alarms with emphasis on ventricular tachycardia.

    PubMed

    Rodrigues, Rui; Couto, Paula

    2016-08-01

    Our approach to detecting false arrhythmia alarms in the intensive care unit breaks down into several tasks. It involves beat detection on different signals: electrocardiogram, photoplethysmogram and arterial blood pressure. The quality of each channel has to be estimated in order to evaluate the reliability of obtained beat detections. The information about the heart rate from the different channels must be integrated in order to find a final conclusion. Some alarm types require particular detectors as is the case of ventricular fibrillation. To identify false ventricular tachycardia alarms we needed to classify heart beats as normal/ventricular. For that purpose we introduce a new feature, QRS polarity type. This feature was important in order to reduce misclassification of ventricular beats: there was an improvement in the ventricular tachycardia alarm true positive rate from 69% to 81%. However, the true negative rate was reduced from 95% to 69% and our global challenge score (real-time event) dropped from 79.02 to 74.28. Our challenge algorithm achieved the third best score in the 2015 PhysioNet/CinC challenge event 1 (real time). PMID:27454934

  7. Methodological Issues in the Quantification of Respiratory Sinus Arrhythmia

    PubMed Central

    Denver, John W.; Reed, Shawn F.; Porges, Stephen W.

    2007-01-01

    Although respiratory sinus arrhythmia (RSA) is a commonly quantified physiological variable, the methods for quantification are not consistent. This manuscript questions the assumption that respiration frequency needs to be manipulated or monitored to generate an accurate measure of RSA amplitude. A review of recent papers is presented that contrast RSA amplitude with measures that use respiratory parameters to adjust RSA amplitude. In addition, data from two studies are presented to evaluate empirically both the relation between RSA amplitude and respiration frequency and the covariation between RSA frequency and respiration frequency. The literature review demonstrates similar findings between both classes of measures. The first study demonstrates, during spontaneous breathing without task demands, that there is no relation between respiration frequency and RSA amplitude and that respiration frequency can be accurately derived from the heart period spectrum (i.e., frequency of RSA). The second study demonstrates that respiration frequency is unaffected by atropine dose, a manipulation that systematically mediates the amplitude of RSA, and that the tight linkage between the RSA frequency and respiration frequency is unaffected by atropine. The research shows that the amplitude of RSA is not affected by respiration frequency under either baseline conditions or vagal manipulation via atropine injection. Respiration frequency is therefore unlikely to be a concern under these conditions. Research examining conditions that produce (causal) deviations from the intrinsic relation between respiratory parameters and the amplitude of RSA combined with appropriate statistical procedures for understanding these deviations are necessary. PMID:17067734

  8. Thinking about breathing: Effects on respiratory sinus arrhythmia.

    PubMed

    Mortola, Jacopo P; Marghescu, Domnica; Siegrist-Johnstone, Rosemarie

    2016-03-01

    Respiratory sinus arrhythmia (RSA), the increase and decrease in instantaneous heart rate (HR) with inspiration and expiration, is commonly evaluated as function of breathing frequency f. However, to the extent that RSA plays a role in the efficiency of gas exchange, it may be expected to correlate better with HR/f ('breathing specific heart rate') than with f, because the former is a better reflection of the cardio-respiratory coupling. We measured RSA breath-by-breath in 209 young men and women during spontaneous breathing and during volitional breathing under auditory cues at vastly different f. In either case, and for both genders, RSA correlated better with HR/f than with f. As HR/f increased so did RSA, in a linear manner. When compared on the basis of HR/f, RSA did not differ significantly between spontaneous and volitional breathing. It is proposed that RSA is a central mechanism that ameliorates the matching between the quasi-continuous pulmonary blood flow and the intermittent airflow, irrespective of the type of ventilatory drive (cortical or autonomic). PMID:26724603

  9. Exact coherent structures: from fluid turbulence to cardiac arrhythmias

    NASA Astrophysics Data System (ADS)

    Grigoriev, Roman; Marcotte, Christopher; Byrne, Gregory

    2014-03-01

    Ventricular fibrillation, a life threatening cardiac arrhythmia, is an example of spatiotemporally chaotic state dominated by multiple interacting spiral waves. Recent studies of weak fluid turbulence suggest that spatiotemporal chaos in general can be understood as a walk among exact unstable regular solutions (exact coherent states, ECS) of nonlinear evolution equations. Several classes of ECS are believed to play a dominant role; most typically these are equilibria and periodic orbits or relative equilibria and relative periodic orbits for systems with global continuous symmetries. Numerical methods originally developed in the context of fluid turbulence can also be applied to models of cardiac dynamics which possess translational and rotational symmetries and, indeed, allowed us to identify relative equilibria and periodic orbits describing isolated spirals with, respectively, fixed and drifting cores. In order to find regular solutions featuring multiple interacting spirals a new approach is required that takes into consideration the dynamics of slowly drifting cores associated with local, rather than global, symmetries. We describe how local symmetries can be reduced and more general types of ECS computed that dominate spiral wave chaos in models of cardiac tissue.

  10. Human sinus arrhythmia: inconsistencies of a teleological hypothesis.

    PubMed

    Tzeng, Y C; Sin, P Y W; Galletly, D C

    2009-01-01

    Respiratory sinus arrhythmia (RSA) may serve an inherent function in optimizing pulmonary gas exchange efficiency via clustering and scattering of heart beats during the inspiratory and expiratory phases of the respiratory cycle. This study sought to determine whether physiological levels of RSA, enhanced by slow paced breathing, caused more heart beats to cluster in inspiration. In 12 human subjects, we analyzed the histogram distribution of heart beats throughout the respiratory cycle during paced breathing at 12, 9, and 6 breaths/min (br/min). The inspiratory period-to-respiratory period ratio was fixed at approximately 0.5. RSA and its relationship with respiration was characterized in the phase domain by average cubic-spline interpolation of electrocardiographic R wave-to-R wave interval fluctuations throughout all respiratory cycles. Although 6 br/min breathing was associated with a significant increase in RSA amplitude (P < 0.01), we observed no significant increase in the proportion of heart beats in inspiration (P = 0.34). Contrary to assumptions in the literature, we observed no significant clustering of heart beats even with high levels of RSA enhanced by slow breathing. The results of this study do not support the hypothesis that RSA optimizes pulmonary gas exchange efficiency via clustering of heart beats in inspiration. PMID:18978190

  11. Respiratory rate estimation using respiratory sinus arrhythmia from photoplethysmography.

    PubMed

    Karlen, Walter; Brouse, Christopher J; Cooke, Erin; Ansermino, J Mark; Dumont, Guy A

    2011-01-01

    Respiratory rate (RR) is an important measurement for ambulatory care and there is high interest in its detection using unobtrusive mobile devices. For this study, we investigated the estimation of RR from a photoplethysmography (PPG) signal that originated from a pulse oximeter sensor and had a sub-optimal sampling rate. We explored the possibility of estimating RR by extracting respiratory sinus arrhythmia (RSA) from the PPG-derived heart rate variability (HRV) measurement using real-time algorithms. Data from 29 children and 13 adults undergoing general anesthesia were analyzed. We compared the RSA power derived from electrocardiography (ECG) with PPG at the reference RR derived from capnography. The power of the PPG was significantly higher than that of the ECG (182.42 ± 36.75 dB vs. 162.30 ± 43.66 dB). Further, the mean RR error for PPG was lower than ECG. Both PPG and ECG RR estimation techniques were more powerful and reliable in cases of spontaneous ventilation than when pressure controlled ventilation was used. The analysis of cases containing artifacts in the PPG revealed a significant increase in RR error, a trend that was less pronounced for controlled ventilation. These results indicate that the estimation of RR from the sub-optimally sampled PPG signal is possible and more reliable than from the ECG. PMID:22254531

  12. Cardiac bidomain bath-loading effects during arrhythmias: interaction with anatomical heterogeneity.

    PubMed

    Bishop, Martin J; Vigmond, Edward; Plank, Gernot

    2011-12-21

    Cardiac tissue is always surrounded by conducting fluid, both in vivo (blood) and in experimental preparations (Tyrode's solution), which acts to increase conduction velocity (CV) close to the tissue-fluid interface, inducing transmural wavefront curvature. Despite its potential importance, computer modeling studies focused on arrhythmia mechanisms have previously not accounted for these bath-loading effects. Here, we investigate the increase in CV and concomitant change in transmural wavefront profiles upon both propagation and arrhythmia dynamics within models of differing anatomical complexity. In simplified slab models, in absence of transmural fiber rotation, bath-loading induced transmural wavefront curvature dominates, significantly increasing arrhythmia complexity compared to no bath. In the presence of fiber rotation, bath-loading effects are less striking and depend upon propagation direction: the bath accentuates natural concave curvature caused by transmurally rotating fibers, but attenuates convex curvature, which negates overall impact upon arrhythmia complexity. Finally, we demonstrate that the high degree of anatomical complexity within whole ventricular models modulates bath-loading induced transmural wavefront curvature. However, key is the increased surface CV that dramatically reduces both arrhythmia inducibility and resulting complexity by increasing wavelength and reducing the available excitable gap. Our findings highlight the importance of including bath-loading effects during arrhythmia mechanism investigations, which could have implications for interpreting and comparing simulation results with experimental data where such effects are inherently present. PMID:22208185

  13. Cibenzoline versus flecainide in the prevention of paroxysmal atrial arrhythmias: a double-blind randomized study.

    PubMed

    Babuty, D; D'Hautefeuille, B; Scheck, F; Mycinsky, C; Pruvost, P; Peraudeau, P

    1995-05-01

    In a randomized, double-blind, parallel clinical trial, the authors tested and compared flecainide and cibenzoline, a new antiarrhythmic drug, on atrial arrhythmias. Sixty-eight patients (36 men, 32 women, mean age 62.5 +/- 1.6 years) with documented symptomatic paroxysmal atrial arrhythmias (fibrillation in 56, flutter in 12) were recruited and received either cibenzoline 260 mg/day (n = 33) or flecainide 200 mg/day (n = 35). Patients were assessed with physical examination, resting ECG, 24-hour ambulatory ECG recording, two-dimensional echocardiography, and standard biologic titrations before the inclusion day, and 3 months and 6 months after the randomization day. Sixteen patients were withdrawn (7 were lost to follow-up, 7 had side effects, 2 had another medical event). Seventeen patients had documented recurrence of atrial arrhythmia (9 in the cibenzoline group, 8 in the flecainide group) during the study. The efficacy of cibenzoline and flecainide for preventing recurrence of atrial arrhythmias was not significantly different (62.5% versus 71.4%). Eleven patients complained of one or more side effects (cibenzoline, n = 6; flecainide, n = 5), justifying leaving the trial in 6 cases (cibenzoline, n = 3; flecainide, n = 3). Two ventricular proarrhythmic effects were observed. No atrial proarrhythmic effects were reported. The efficacy of cibenzoline and flecainide for preventing atrial arrhythmia is good and similar during a follow-up period of 6 months. In view of these results, cibenzoline may be administered first to prevent atrial arrhythmia. PMID:7657846

  14. Shensong Yangxin capsules prevent ischemic arrhythmias by prolonging action potentials and alleviating Ca2+ overload.

    PubMed

    Zhao, Yixiu; Gao, Feng; Zhang, Yong; Wang, Hongtao; Zhu, Jiuxin; Chang, Liping; Du, Zhimin; Zhang, Yan

    2016-06-01

    Shensong Yangxin capsules (SSYX) are an effective traditional Chinese medicine that has been used to treat coronary heart disease clinically. The present study aimed to establish whether SSYX prevent ischemic arrhythmias in rats, and to explore the underlying mechanisms. Male rats were pretreated with distilled water, SSYX and amiodarone for one week. Acute myocardial ischemia (AMI) was performed to induce ischemic arrhythmias. The incidence and severity of ischemic arrhythmias were evaluated. The action potential, transient outward K+ current (Ito) and inward rectifier K+ current (IK1) of rat cardiomyocytes were measured using the patch‑clamp technique. The intracellular Ca2+ concentration of the cardiomyocytes was measured using a laser scanning confocal microscope. The results revealed that SSYX lowered the incidence of arrhythmia markedly during AMI. Furthermore, SSYX delayed the appearance, and reduced the severity, of ischemic arrhythmias compared with the control. In addition, SSYX markedly decreased the ratio of the myocardial infarction region to the whole heart. In an in vitro study, SSYX prolonged the action potential duration of rat cardiomyocytes, and inhibited Ito and IK1 markedly. Additionally, SSYX inhibited Ca2+ elevation induced by KCl in cardiomyocytes. These results suggested that SSYX prevents ischemic arrhythmia, and the underlying mechanism responsible for this process may include prolonging the action potential and alleviating Ca2+ overload. PMID:27122298

  15. Sympathetic restraint of respiratory sinus arrhythmia: implications for vagal-cardiac tone assessment in humans

    NASA Technical Reports Server (NTRS)

    Taylor, J. A.; Myers, C. W.; Halliwill, J. R.; Seidel, H.; Eckberg, D. L.

    2001-01-01

    Clinicians and experimentalists routinely estimate vagal-cardiac nerve traffic from respiratory sinus arrhythmia. However, evidence suggests that sympathetic mechanisms may also modulate respiratory sinus arrhythmia. Our study examined modulation of respiratory sinus arrhythmia by sympathetic outflow. We measured R-R interval spectral power in 10 volunteers that breathed sequentially at 13 frequencies, from 15 to 3 breaths/min, before and after beta-adrenergic blockade. We fitted changes of respiratory frequency R-R interval spectral power with a damped oscillator model: frequency-dependent oscillations with a resonant frequency, generated by driving forces and modified by damping influences. beta-Adrenergic blockade enhanced respiratory sinus arrhythmia at all frequencies (at some, fourfold). The damped oscillator model fit experimental data well (39 of 40 ramps; r = 0.86 +/- 0.02). beta-Adrenergic blockade increased respiratory sinus arrhythmia by amplifying respiration-related driving forces (P < 0.05), without altering resonant frequency or damping influences. Both spectral power data and the damped oscillator model indicate that cardiac sympathetic outflow markedly reduces heart period oscillations at all frequencies. This challenges the notion that respiratory sinus arrhythmia is mediated simply by vagal-cardiac nerve activity. These results have important implications for clinical and experimental estimation of human vagal cardiac tone.

  16. An ameliorative protocol for the quantification of purine 5',8-cyclo-2'-deoxynucleosides in oxidized DNA

    NASA Astrophysics Data System (ADS)

    Terzidis, Michael; Chatgilialoglu, Chryssostomos

    2015-07-01

    5',8-Cyclo-2'-deoxyadenosine (cdA) and 5',8-cyclo-2'-deoxyguanosine (cdG) are lesions resulting from hydroxyl radical (HO•) attack on the 5'H of the nucleoside sugar moiety and exist in both 5'R and 5'S diastereomeric forms. Increased levels of cdA and cdG are linked to Nucleotide Excision Repair mechanism deficiency and mutagenesis. Discrepancies in the damage measurements reported over recent years indicated the weakness of the actual protocols, in particular for ensuring the quantitative release of these lesions from the DNA sample and the appropriate method for their analysis. Herein we report the detailed revision leading to a cost-effective and efficient protocol for the DNA damage measurement, consisting of the nuclease benzonase and nuclease P1 enzymatic combination for DNA digestion followed by liquid chromatography isotope dilution tandem mass spectrometry analysis.

  17. Selective excavation of human carious dentin using the nanosecond pulsed laser in 5.8-μm wavelength range

    NASA Astrophysics Data System (ADS)

    Kita, Tetsuya; Ishii, Katsunori; Yoshikawa, Kazushi; Yasuo, Kenzo; Yamamoto, Kazuyo; Awazu, Kunio

    Less-invasive treatment of caries has been needed in laser dentistry. Based on the absorption property of dentin substrates, 6 μm wavelength range shows specific absorptions and promising characteristics for the excavation. In our previous study, 5.8 μm wavelength range was found to be effective for selective excavation of carious dentin and restoration treatment using composite resin from the irradiation experiment with bovine sound and demineralized dentin. In this study, the availability of 5.8 μm wavelength range for selective excavation of human carious dentin was investigated for clinical application. A mid-infrared tunable nanosecond pulsed laser by difference-frequency generation was used for revealing the ablation property of human carious dentin. Irradiation experiments indicated that the wavelength of 5.85 μm and the average power density of 30 W/cm2 realized the selective excavation of human carious dentin, but ablation property was different with respect to each sample because of the different caries progression. In conclusion, 5.8 μm wavelength range was found to be effective for selective excavation of human carious dentin.

  18. Assessment of cumulative evidence for the association between glutathione S-transferase polymorphisms and lung cancer: application of the Venice interim guidelines

    PubMed Central

    Langevin, Scott M.; Ioannidis, John P.A.; Vineis, Paolo; Taioli, Emanuela

    2010-01-01

    There is an overwhelming abundance of genetic association studies available in the literature, which often can be collectively difficult to interpret. To address this issue, the Venice interim guidelines were established for determining the credibility of the cumulative evidence. The objective of this report is to evaluate the literature on the association of common GST variants (GSTM1 null, GSTT1 null and GSTP1 Ile105Val polymorphism) and lung cancer, and to assess the credibility of the associations using the newly proposed cumulative evidence guidelines. Information from the literature was enriched with an updated meta-analysis and a pooled analysis using data from the Genetic Susceptibility to Environmental Carcinogens (GSEC) database. There was a significant association between GSTM1 null and lung cancer for the meta- (meta OR = 1.17, 95% CI: 1.10–1.25) and pooled analysis (adjusted OR = 1.10, 95% CI: 1.04–1.16), although substantial heterogeneity was present. No overall association between lung cancer and GSTT1 null or GSTP1 Ile105Val was found. When the Venice criteria was applied, cumulative evidence for all associations were considered “weak”, with the exception of East Asian carriers of the G allele of GSTP1 Ile105Val, which was graded as “moderate” evidence. In spite of large amounts of studies, and several statistically significant summary estimates produced by meta-analyses, the application of the Venice criteria suggests extensive heterogeneity and susceptibility to bias for the studies on association of common genetic polymorphisms, such as with GST variants and lung cancer. PMID:20729793

  19. Temporal changes and spatial variation of soil oxygen consumption, nitrification and denitrification rates in a tidal salt marsh of the Lagoon of Venice, Italy

    NASA Astrophysics Data System (ADS)

    Eriksson, P. G.; Svensson, J. M.; Carrer, G. M.

    2003-12-01

    The aim of the present study was to investigate seasonal and spatial patterns of soil oxygen consumption, nitrification, denitrification and fluxes of dissolved inorganic nitrogen (DIN) in a tidal salt marsh of the Lagoon of Venice, Italy. In the salt marsh, intact soil cores including overlying water were collected monthly at high tide from April to October in salt marsh creeks and in areas covered by the dominant vegetation, Limonium serotinum. In May, cores were also collected in areas with vegetation dominated by Juncus maritimus and Halimione portulacoides. In laboratory incubations at in situ temperature in the dark, flux rates of oxygen and DIN were monitored in the overlying water of the intact cores. 15N-nitrate was added to the overlying water and nitrification and denitrification were measured using isotope-dilution and -pairing techniques. The results show that highest soil oxygen consumption coincided with the highest water temperature in June and July. The highest denitrification rates were recorded in spring and autumn coinciding with the highest nitrate concentrations. Soil oxygen consumption and nitrification rates differed between sampling sites, but denitrification rates were similar among the different vegetation types. The highest rates were recorded in areas covered with L. serotinum. Burrowing soil macrofauna enhanced oxygen consumption, nitrification and denitrification in April and May. The data presented in this study indicate high temporal as well as spatial variations in the flux of oxygen and DIN, and nitrogen transformations in the tidal salt marshes of the Venice lagoon during the growth season. The results identify the salt marshes of the Venice lagoon as being metabolically very active ecosystems with a high capacity to process nitrogen.

  20. Exploiting periodicity to extract the atrial activity in atrial arrhythmias

    NASA Astrophysics Data System (ADS)

    Llinares, Raul; Igual, Jorge

    2011-12-01

    Atrial fibrillation disorders are one of the main arrhythmias of the elderly. The atrial and ventricular activities are decoupled during an atrial fibrillation episode, and very rapid and irregular waves replace the usual atrial P-wave in a normal sinus rhythm electrocardiogram (ECG). The estimation of these wavelets is a must for clinical analysis. We propose a new approach to this problem focused on the quasiperiodicity of these wavelets. Atrial activity is characterized by a main atrial rhythm in the interval 3-12 Hz. It enables us to establish the problem as the separation of the original sources from the instantaneous linear combination of them recorded in the ECG or the extraction of only the atrial component exploiting the quasiperiodic feature of the atrial signal. This methodology implies the previous estimation of such main atrial period. We present two algorithms that separate and extract the atrial rhythm starting from a prior estimation of the main atrial frequency. The first one is an algebraic method based on the maximization of a cost function that measures the periodicity. The other one is an adaptive algorithm that exploits the decorrelation of the atrial and other signals diagonalizing the correlation matrices at multiple lags of the period of atrial activity. The algorithms are applied successfully to synthetic and real data. In simulated ECGs, the average correlation index obtained was 0.811 and 0.847, respectively. In real ECGs, the accuracy of the results was validated using spectral and temporal parameters. The average peak frequency and spectral concentration obtained were 5.550 and 5.554 Hz and 56.3 and 54.4%, respectively, and the kurtosis was 0.266 and 0.695. For validation purposes, we compared the proposed algorithms with established methods, obtaining better results for simulated and real registers.

  1. Iatrogenic QT Abnormalities and Fatal Arrhythmias: Mechanisms and Clinical Significance

    PubMed Central

    Cubeddu, Luigi X

    2009-01-01

    Severe and occasionally fatal arrhythmias, commonly presenting as Torsade de Pointes [TdP] have been reported with Class III-antiarrhythmics, but also with non-antiarrhythmic drugs. Most cases result from an action on K+ channels encoded by the HERG gene responsible for the IKr repolarizing current, leading to a long QT and repolarization abnormalities. The hydrophobic central cavity of the HERG-K+ channels, allows a large number of structurally unrelated drugs to bind and cause direct channel inhibition. Some examples are dofetilide, quinidine, sotalol, erythromycin, grepafloxacin, cisapride, dolasetron, thioridazine, haloperidol, droperidol and pimozide. Other drugs achieve channel inhibition indirectly by impairing channel traffic from the endoplasmic reticulum to the cell membrane, decreasing channel membrane density (pentamidine, geldalamicin, arsenic trioxide, digoxin, and probucol). Whereas, ketoconazole, fluoxetine and norfluoxetine induce both direct channel inhibition and impaired channel trafficking. Congenital long QT syndrome, subclinical ion-channel mutations, subjects and relatives of subjects with previous history of drug-induced long QT or TdP, dual drug effects on cardiac repolarization [long QT plus increased QT dispersion], increased transmural dispersion of repolarization and T wave abnormalities, use of high doses, metabolism inhibitors and/or combinations of QT prolonging drugs, hypokalemia, structural cardiac disease, sympathomimetics, bradycardia, women and older age, have been shown to increase the risk for developing drug-induced TdP. Because most of these reactions are preventable, careful evaluation of risk factors and increased knowledge of drugs use associated with repolarization abnormalities is strongly recommended. Future genetic testing and development of practical and simple provocation tests are in route to prevent iatrogenic TdP. PMID:20676275

  2. Detection and Prevention of Cardiac Arrhythmias During Space Flight

    NASA Technical Reports Server (NTRS)

    Pillai, Dilip; Rosenbaum, David S.; Liszka, Kathy J.; York, David W.; Mackin, Michael A.; Lichter, Michael J.

    2004-01-01

    There have been reports suggesting that long-duration space flight might lead to an increased risk of potentially serious heart rhythm disturbances. If space flight does, in fact, significantly decrease cardiac electrical stability, the effects could be catastrophic, potentially leading to sudden cardiac death. It will be important to determine the mechanisms underlying this phenomenon in order to prepare for long-term manned lunar and interplanetary missions and to develop appropriate countermeasures. Our hypothesis is that prolonged exposure to microgravity will alter T wave alternans measurements, decrease heart rate variance, increase QT dispersion, decrease heart rate recovery and alter QT restitution curve. A recently published study has shown that long duration spaceflights prolong cardiac conduction and repolarization. They concluded that long duration flight is associated with QT interval prolongation and may increase arrhythmia susceptibility. We propose using computer technology as a noninvasive clinical tool to detect and study clinically significant TWA during standard exercise testing using electrode systems specifically adapted for the purpose of obtaining and measuring TWA. A population of approximately 15 healthy men and 5 healthy women subjects, representative of the astronaut cohort will be asked to voluntarily participate in this study. Their blood pressure and ECG/TWA will be measured pre-flight and in-flight. Prior to flight, subjects will be asked to participate in an orientation session. Still photos will be taken of the skin where the conductive gel is used for the multi-segment sensors. Photos will be recorded preflight, immediately postflight, and several times during the proceeding week until it has been determined that any skin reaction has disappeared or that no rash is present and will not appear.

  3. Effect of Different Pranayamas on Respiratory Sinus Arrhythmia

    PubMed Central

    Raj, Jeneth Berlin; Ramanathan, Meena; Trakroo, Madanmohan

    2016-01-01

    Introduction Respiratory Sinus Arrhythmia (RSA) is the differential change of Heart Rate (HR) in response to inspiration and expiration. This is a noninvasive sensitive index of parasympathetic cardiac control. Aim To evaluate changes in RSA by utilizing a simple and cost-effective analysis of electrocardiographic (ECG) tracings obtained during performance of four pranayama techniques. Materials and Methods Fifty two trained volunteers performed the following pranayamas with different ratios for inspiration and expiration: sukha (1:1), traditional (1:2), pranava (1:3) and savitri (2:1:2:1) and ECG was recorded while performing the techniques with rest period of 5 minutes in-between. HR was calculated and maximum HR during inspiration (Imax), minimum HR during expiration (Emin), differences between Imax and Emin (Δ), percentage differences between Imax and Emin (Δ%) and expiration: inspiration ratio (E:I) calculated by respective formulae. Statistical analysis was carried out using repeated measures of ANOVA with Tukey-Kramer multiple comparisons test. Results There were significant differences between groups in all five aspects namely: p= 0.0093 for mean Imax, p = 0.0009 for mean Emin, and p < 0.0001 for Δ HR (I-E), Δ% HR (I-E) and E:I ratio. Pranava pranayama produced the greatest changes in all five comparisons. Conclusion We suggest that further short and long term studies be undertaken with pranava pranayama in patients to further qualitatively and quantitatively evaluate inherent mechanisms of this simple technique. Addition of these cost-effective techniques to the medical armory will help patients of rhythm disorders and other cardiovascular conditions. PMID:27134863

  4. Transgenic Insights Linking Pitx2 and Atrial Arrhythmias

    PubMed Central

    Franco, Diego; Chinchilla, Ana; Aránega, Amelia E.

    2012-01-01

    Pitx2 is a homeobox transcription factor involved in left–right signaling during embryogenesis. Disruption of left–right signaling in mice within its core nodal/lefty cascade, results in impaired expression of the last effector of the left–right cascade, Pitx2, leading in many cases to absence or bilateral expression of Pitx2 in lateral plate mesoderm (LPM). Loss of Pitx2 expression in LPM results in severe cardiac malformations, including right cardiac isomerism. Pitx2 is firstly expressed asymmetrically in the left but not right LPM, before the cardiac crescent forms, and subsequently, as the heart develops, becomes confined to the left side of the linear heart tube. Expression of Pitx2 is remodeled during cardiac looping, becoming localized to the ventral portion of the developing ventricular chambers, while maintaining a distinct left-sided atrial expression. The importance of Pitx2 during cardiogenesis has been illustrated by the complex and robust cardiac defects observed on systemic deletion of Pitx2 in mice. Lack of Pitx2 expression leads to embryonic lethality at mid-term, and Pitx2-deficient embryos display isomeric hearts with incomplete closure of the body wall. However, whereas the pivotal role of Pitx2 during cardiogenesis is well sustained, its putative role in the fetal and adult heart is largely unexplored. Recent genome-wide association studies have identified several genetic variants highly associated with atrial fibrillation (AF). Among them are genetic variants located on chromosome 4q25 adjacent to PITX2. Since then several transgenic approaches have provided evidences of the role of the homeobox transcription factor PITX2 and atrial arrhythmias. Here, we review new insights into the cellular and molecular links between PITX2 and AF. PMID:22701438

  5. The effects of clam fishing on the properties of surface sediments in the lagoon of Venice, Italy

    NASA Astrophysics Data System (ADS)

    Aspen, R. J.; Vardy, S.; Perkins, R. G.; Davidson, I. R.; Bates, R.; Paterson, D. M.

    Harvesting of clams(Tapes philippinarum) has important socio-economic and environmental implications for the Venice lagoon area, Italy. Clam harvesting disrupts the structure of benthic communities but the effects upon sediment stability and surface structure remain unclear. The effect of clam fishing on the sediment properties of the lagoon bed was investigated at two different sites, a heavily fished site (San Angelo) and an infrequently fished site (San Giaccomo). Both sites were assessed for immediate impacts of fishing, using indicators of biogenic sediment stabilisation. Samples were taken at three points along three 100 m linear transects at each site prior to and post fishing. Paired samples were also taken parallel to each transect at a distance of 5m, to allow for temporal variation. Sediment stability, measured with a cohesive strength meter (CSM), was significantly higher at the less impacted site (F1,34 = 6.23, p < 0.018), was correlated with indicators of biogenic sediment stabilisation and decreased by approximately 50% following the trawling event. Concomitant decreases in chlorophyll a (chl a), colloidal-S carbohydrate and dry bulk density were observed on the transect after fishing but not adjacent to the fishing path. At the heavily impacted site, clam fishing by trawling had, in general, no significant effect on the biological and physical properties (although chl a did decrease significantly after fishing). The lack of a significant impact from fishing at the impacted site was attributed to the higher frequency of fishing occurring in this area. Hence, frequent fishing of the lagoon prevents establishment of biotic communities, preventing biostabilisation and thus reduces the stability of the surface sediment.

  6. Variability of cannabis potency in the Venice area (Italy): a survey over the period 2010-2012.

    PubMed

    Zamengo, Luca; Frison, Giampietro; Bettin, Chiara; Sciarrone, Rocco

    2014-01-01

    Cannabis is the most widely used illicit substance globally, with an estimated annual prevalence in 2010 of 2.6-5.0% of the adult population. Concerns have been expressed about increases in the potency of cannabis products. A high tetrahydrocannabinol (THC) content can increase anxiety, depression, and psychotic symptoms, and can increase the risk of dependence and adverse effects on the respiratory and cardiovascular systems in regular users. The aim of this study was to report statistical data about the potency of cannabis products seized in the north-east of Italy, in a geographical area centred in Venice and extending for more than 10,000  km(2) with a population of more than two million, by investigating the variability observed in THC levels of about 4000 samples of cannabis products analyzed over the period 2010-2012. Overall median THC content showed an increasing trend over the study period from about 6.0% to 8.1% (6.2-8.9% for cannabis resin, 5.1-7.6% for herbal cannabis). The variation in the THC content of individual samples was very large, ranging from 0.3% to 31% for cannabis resin and from 0.1 to 19% for herbal cannabis. Median CBN:THC ratios showed a slightly decreasing trend over the study period, from 0.09 (2010) to 0.03 (2012), suggesting an increasing freshness of submitted materials. Median CBD:THC ratios also showed a decreasing trend over the study from about 0.52 (2010) to 0.18 (2012), likely due to the increase in submissions of materials from indoor and domestic cultivation with improved breeding methods. PMID:23868754

  7. Source apportionment of wide range particle size spectra and black carbon collected at the airport of Venice (Italy)

    NASA Astrophysics Data System (ADS)

    Masiol, Mauro; Vu, Tuan V.; Beddows, David C. S.; Harrison, Roy M.

    2016-08-01

    Atmospheric particles are of high concern due to their toxic properties and effects on climate, and large airports are known as significant sources of particles. This study investigates the contribution of the Airport of Venice (Italy) to black carbon (BC), total particle number concentrations (PNC) and particle number size distributions (PNSD) over a large range (14 nm-20 μm). Continuous measurements were conducted between April and June 2014 at a site located 110 m from the main taxiway and 300 m from the runway. Results revealed no significantly elevated levels of BC and PNC, but exhibited characteristic diurnal profiles. PNSD were then analysed using both k-means cluster analysis and positive matrix factorization. Five clusters were extracted and identified as midday nucleation events, road traffic, aircraft, airport and nighttime pollution. Six factors were apportioned and identified as probable sources according to the size profiles, directional association, diurnal variation, road and airport traffic volumes and their relationships to micrometeorology and common air pollutants. Photochemical nucleation accounted for ∼44% of total number, followed by road + shipping traffic (26%). Airport-related emissions accounted for ∼20% of total PNC and showed a main mode at 80 nm and a second mode beyond the lower limit of the SMPS (<14 nm). The remaining factors accounted for less than 10% of number counts, but were relevant for total volume concentrations: nighttime nitrate, regional pollution and local resuspension. An analysis of BC levels over different wind sectors revealed no especially significant contributions from specific directions associated with the main local sources, but a potentially significant role of diurnal dynamics of the mixing layer on BC levels. The approaches adopted in this study have identified and apportioned the main sources of particles and BC at an international airport located in area affected by a complex emission scenario. The

  8. Tiaogan Qingxin Granule treatment increases myocardial connexin 43 expression in a rat model of arrhythmia.

    PubMed

    Yao, J H; Qu, C H; Ma, L; Chang, X Z

    2016-01-01

    Myocardial ischemia-induced arrhythmia, especially ventricular arrhythmia, is the main reason for sudden cardiac death. Therefore, ischemic ventricular arrhythmia-targeted treatments are urgently needed. The mechanism of Tiaogan Qingxin Granule in premature ventricular beat (PVB) treatment was explored in arrhythmic rats pretreated with Tiaogan Qingxin Granule. Sprague-Dawley rats (N = 40) were randomly divided into 4 groups: sham-operated, arrhythmia model, Wenxin Granule, and Tiaogan Qingxin Granule. The ischemic arrhythmia model was established by ligating the left anterior descending coronary artery. The Tiaogan Qingxin Granule group was treated intragastrically for 7 days before surgery. Sham-operated rats underwent thoracotomy without coronary artery ligation. Myocardial infarction rate was measured using the triphenyltetrazolium chloride method and Cx43 expression was quantified by western blotting. Compared to the arrhythmia model group, the Tiaogan Qingxin Granule group showed a significant reduction in the myocardial infarct size and myocardial infarction rate (P < 0.01). Cx43 expression in the left ventricular myocardial tissues was significantly lower in the arrhythmia model group than in the sham-operated group (P < 0.01), but significantly higher in the Tiaogan Qingxin Granule group (P < 0.01). Intergroup difference in the relative Cx43 expression between the Tiaogan Qingxin Granule and Wenxin Granule groups was not significant (P > 0.05). Thus, Tiaogan Qingxin Granule reduced the myocardial infarct size, lowered the myocardial infarction rate, and increased Cx43 expression, possibly by increasing blood supply to the cardiac muscles. In conclusion, Tiaogan Qingxin Granule may be useful for treating ischemic PVB. PMID:27323125

  9. Defining new insight into atypical arrhythmia: a computational model of ankyrin-B syndrome

    PubMed Central

    Wolf, Roseanne M.; Mitchell, Colleen C.; Christensen, Matthew D.; Mohler, Peter J.

    2010-01-01

    Normal cardiac excitability depends on the coordinated activity of specific ion channels and transporters within specialized domains at the plasma membrane and sarcoplasmic reticulum. Ion channel dysfunction due to congenital or acquired defects has been linked to human cardiac arrhythmia. More recently, defects in ion channel-associated proteins have been associated with arrhythmia. Ankyrin-B is a multifunctional adapter protein responsible for targeting select ion channels, transporters, cytoskeletal proteins, and signaling molecules in excitable cells, including neurons, pancreatic β-cells, and cardiomyocytes. Ankyrin-B dysfunction has been linked to cardiac arrhythmia in human patients and ankyrin-B heterozygous (ankyrin-B+/−) mice with a phenotype characterized by sinus node dysfunction, susceptibility to ventricular arrhythmias, and sudden death (“ankyrin-B syndrome”). At the cellular level, ankyrin-B+/− cells have defects in the expression and membrane localization of the Na+/Ca2+ exchanger and Na+-K+-ATPase, Ca2+ overload, and frequent afterdepolarizations, which likely serve as triggers for lethal cardiac arrhythmias. Despite knowledge gathered from mouse models and human patients, the molecular mechanism responsible for cardiac arrhythmias in the setting of ankyrin-B dysfunction remains unclear. Here, we use mathematical modeling to provide new insights into the cellular pathways responsible for Ca2+ overload and afterdepolarizations in ankyrin-B+/− cells. We show that the Na+/Ca2+ exchanger and Na+-K+-ATPase play related, yet distinct, roles in intracellular Ca2+ accumulation, sarcoplasmic reticulum Ca2+ overload, and afterdepolarization generation in ankyrin-B+/− cells. These findings provide important insights into the molecular mechanisms underlying a human disease and are relevant for acquired human arrhythmia, where ankyrin-B dysfunction has recently been identified. PMID:20729400

  10. New directions in cardiac arrhythmia management: present challenges and future solutions.

    PubMed

    Nattel, Stanley; Andrade, Jason; Macle, Laurent; Rivard, Lena; Dyrda, Katia; Mondesert, Blandine; Khairy, Paul

    2014-12-01

    Cardiac arrhythmias are a major contributor to population morbidity and mortality. Enormous advances in arrhythmia management have occurred over the 60 years since the founding of the Montreal Heart Institute, but important challenges remain. The purpose of this article is to identify the areas of cardiac arrhythmia therapy that need improvement and to discuss the evolving approaches that promise solutions. Challenges in diagnosis, detection, and risk-stratification include difficulties in separating benign from high-risk syncope and pinpointing the underlying causes, the detection of silent atrial fibrillation in patients at risk of stroke, and inadequate identification of sudden-death risk. Implantable devices are limited by the need for battery and device replacements, device complications like infection and dysfunction, and lead complications like fracture, infection, or displacement. Antiarrhythmic drug therapy, although widely used, is plagued by a very limited range of available agents, supply issues, insufficient efficacy, and significant adverse effect risk. Health economic concerns include the high cost of new technologies, challenges in establishing cost effectiveness, and restrictive practices of government or third-party payers. Major improvements in arrhythmia management can be expected from new discoveries and technological developments in genetics, innovative diagnostic tools for arrhythmia monitoring, imaging and analysis, new approaches to antiarrhythmic drug development, biological therapies, and continuing improvement in implantable device technology like further miniaturization, leadless technology, and use of novel energy sources. As exciting as the developments in arrhythmia management have been in the past, we can look forward to exponential improvement in our ability to manage arrhythmia patients in the near future. PMID:25432137

  11. Zygotic LvBMP5-8 is required for skeletal patterning and for left-right but not dorsal-ventral specification in the sea urchin embryo.

    PubMed

    Piacentino, Michael L; Chung, Oliver; Ramachandran, Janani; Zuch, Daniel T; Yu, Jia; Conaway, Evan A; Reyna, Arlene E; Bradham, Cynthia A

    2016-04-01

    Skeletal patterning in the sea urchin embryo requires coordinated signaling between the pattern-dictating ectoderm and the skeletogenic primary mesenchyme cells (PMCs); recent studies have begun to uncover the molecular basis for this process. Using an unbiased RNA-Seq-based screen, we have previously identified the TGF-ß superfamily ligand, LvBMP5-8, as a skeletal patterning gene in Lytechinus variegatus embryos. This result is surprising, since both BMP5-8 and BMP2/4 ligands have been implicated in sea urchin dorsal-ventral (DV) and left-right (LR) axis specification. Here, we demonstrate that zygotic LvBMP5-8 is required for normal skeletal patterning on the left side, as well as for normal PMC positioning during gastrulation. Zygotic LvBMP5-8 is required for expression of the left-side marker soxE, suggesting that LvBMP5-8 is required for left-side specification. Interestingly, we also find that LvBMP5-8 knockdown suppresses serotonergic neurogenesis on the left side. While LvBMP5-8 overexpression is sufficient to dorsalize embryos, we find that zygotic LvBMP5-8 is not required for normal DV specification or development. In addition, ectopic LvBMP5-8 does not dorsalize LvBMP2/4 morphant embryos, indicating that, in the absence of BMP2/4, BMP5-8 is insufficient to specify dorsal. Taken together, our data demonstrate that zygotic LvBMP5-8 signaling is essential for left-side specification, and for normal left-side skeletal and neural patterning, but not for DV specification. Thus, while both BMP2/4 and BMP5-8 regulate LR axis specification, BMP2/4 but not zygotic BMP5-8 regulates DV axis specification in sea urchin embryos. PMID:26905309

  12. MS-551 and KCB-328, two class III drugs aggravated adrenaline-induced arrhythmias

    PubMed Central

    Xue, YiXue; Yamada, Chikaomi; Nu Aye, Nu; Hashimoto, Keitaro

    1998-01-01

    We investigated the proarrhythmic effects of MS-551 and KCB-328, class III antiarrhythmic drugs using adrenaline-induced arrhythmia models in halothane anaesthetized, closed-chest dogs. In the control period, adrenaline, starting from a low dose of 0.25 to up to 1.0 μg/kg/50 s i.v., was injected to determine the arrhythmia inducing dose and the non-inducing dose. After MS-551 or KCB-328 administration, the adrenaline injection was repeated and the interval between the injection and the occurrence of arrhythmia (latent interval), the changes in arrhythmic ratio (as calculated by dividing the number of ventricular premature contraction by the number of the total heart rate) and the severity of arrhythmia were observed. MS-551 infusion, 1 mg/kg/30 min, decreased the heart rate (HR) by 16% (P<0.01) and prolonged the QTc interval by 20% (P<0.01). During the 30 min of MS-551 infusion, arrhythmias occurred in three out of seven dogs (torsades de pointes (TdP) type VT in one dog). After these arrhythmias disappeared, MS-551 decreased the latent interval of the adrenaline arrhythmias produced by the inducing dose (30±2 s compared with 43±3 s of the control interval, P<0.05), increased the arrhythmic ratio (P<0.05) and induced arrhythmias by non-inducing adrenaline doses (P<0.05). Effect of a new class III drug KCB-328 infusion, 0.3 mg/kg/30 min, was compared witih MS-551 using the same model. KCB-328 decreased the HR by 21% (P<0.01) and prolonged the QTc interval by 25% (P<0.01). During the 30 min of infusion, arrhythmias occurred in five out of seven dogs (TdP in two dogs). KCB-328 also decreased the latent interval of the adrenaline arrhythmias produced by the inducing doses (31±3 s compared with 49±7 s of the control period, P<0.05), but did not significantly alter the arrhythmic ratio. Adrenaline induced TdP only after MS-551 or KCB-328 was administered, i.e. after MS-551, 1 mg/kg/30 min, 3/7 versus 0/7 in the control; KCB, 0.3

  13. Oral fluoroquinolone use and serious arrhythmia: bi-national cohort study

    PubMed Central

    Svanström, Henrik; Melbye, Mads; Pasternak, Björn; Hviid, Anders

    2016-01-01

    Objective To evaluate if oral fluoroquinolone use is associated with an increased risk of serious arrhythmia. Design Bi-national cohort study, linking register data on filled prescriptions, cases of serious arrhythmia, and patient characteristics. Setting Denmark, 1997-2011; Sweden, 2006-13. Participants The study cohort was derived from a source population of all Danish and Swedish adults, aged 40 to 79 years. 909 656 courses of fluoroquinolone use (ciprofloxacin 82.6%, norfloxacin 12.1%, ofloxacin 3.2%, moxifloxacin 1.2%, and other fluoroquinolones 0.9%) and 909 656 courses of penicillin V use, matched 1:1 on propensity score, were included. Main outcome measure The main outcome was risk of serious arrhythmia (fatal and non-fatal), comparing courses of fluoroquinolone use with courses of penicillin V use (an antibiotic with no pro-arrhythmic effect). The risk period of interest was current use, defined as days 0-7 of treatment. Subgroup analyses were conducted according to country, sex, age, underlying cardiovascular disease, concomitant use of drugs known to increase the risk of torsades de pointes, fluoroquinolone type, and levels of arrhythmia risk score. Results 144 cases of serious arrhythmia occurred during follow-up, 66 among current fluoroquinolone users (incidence rate 3.4 per 1000 person years) and 78 among current penicillin users (4.0 per 1000 person years); comparing oral fluoroquinolone treatment with penicillin V, the rate ratio was 0.85 (95% confidence interval 0.61 to 1.18). Compared with penicillin V, the absolute risk difference was −13 (95% confidence interval −35 to 16) cases of serious arrhythmia per 1 000 000 courses of fluoroquinolones. The risk of serious arrhythmia was not statistically significantly increased in any of the subgroups, including analyses by fluoroquinolone type. Conclusions Contrary to previous reports, oral fluoroquinolone treatment was not associated with an increased risk of serious arrhythmia in the

  14. Intermittent short ECG recording is more effective than 24-hour Holter ECG in detection of arrhythmias

    PubMed Central

    2014-01-01

    Background Many patients report symptoms of palpitations or dizziness/presyncope. These patients are often referred for 24-hour Holter ECG, although the sensitivity for detecting relevant arrhythmias is comparatively low. Intermittent short ECG recording over a longer time period might be a convenient and more sensitive alternative. The objective of this study is to compare the efficacy of 24-hour Holter ECG with intermittent short ECG recording over four weeks to detect relevant arrhythmias in patients with palpitations or dizziness/presyncope. Methods Design: prospective, observational, cross-sectional study. Setting: Clinical Physiology, University Hospital. Patients: 108 consecutive patients referred for ambiguous palpitations or dizziness/presyncope. Interventions: All individuals underwent a 24-hour Holter ECG and additionally registered 30-second handheld ECG (Zenicor EKG® thumb) recordings at home, twice daily and when having cardiac symptoms, during 28 days. Main outcome measures: Significant arrhythmias: atrial fibrillation (AF), paroxysmal supraventricular tachycardia (PSVT), atrioventricular (AV) block II–III, sinus arrest (SA), wide complex tachycardia (WCT). Results 95 patients, 42 men and 53 women with a mean age of 54.1 years, completed registrations. Analysis of Holter registrations showed atrial fibrillation (AF) in two patients and atrioventricular (AV) block II in one patient (= 3.2% relevant arrhythmias [95% CI 1.1–8.9]). Intermittent handheld ECG detected nine patients with AF, three with paroxysmal supraventricular tachycardia (PSVT) and one with AV-block-II (= 13.7% relevant arrhythmias [95% CI 8.2–22.0]). There was a significant difference between the two methods in favour of intermittent ECG with regard to the ability to detect relevant arrhythmias (P = 0.0094). With Holter ECG, no symptoms were registered during any of the detected arrhythmias. With intermittent ECG, symptoms were registered during half of the arrhythmia

  15. The 5-8 Micron Infrared Spectrum of the Galactic Center and the Composition of Interstellar Dust

    NASA Technical Reports Server (NTRS)

    Tielens, A. G. G. M.; Wooden, D. H.; Allamandola, L. J.; Bregman, J.; Witteborn, F. C.; Cuzzi, Jeffery N. (Technical Monitor)

    1995-01-01

    Interstellar dust is an important component of the interstellar medium which dominates the opacity and, hence, regulates radiative transfer, molecule formation, and thermal balance of the ISM. Much of our knowledge on the composition of interstellar dust results from infrared spect,oscopy. The extinction along the line of sight towards the galactic center is believed to be dominated by dust in the diffuse ISM. Because of the high extinction and high IR flux, IR spectra of galactic center sources have been a prime sampling ground for the characteristics of interstellar dust. We have obtained 5-8 micrometer spectra of the galactic center using the KAO. These spectra show absorption features at 5.5, 5.8, 6.1, and 6.8 micrometers. Together with features in the 3 micrometer region previously observed by us using the IRTF, these features are compared to laboratory spectra of candidate materials. We conclude that the 3.0 and 6.1 micrometer feature are carried by H2O, likely in the form of water of hydration in interstellar silicates. The 3.4, 5.5, 5.8, and 6.8 micrometer features are due to CH2, CH3 and C=O stretching and deformation modes in a hydrocarbon grain component. Comparing derived dust abundances, we conclude that silicates dominate the interstellar dust volume. Hydrocarbon and (small) graphite grains contribute each about 0.1. The remainder of the interstellar dust volume does not show strong IR absorption features and is likely in the form of large graphite, amorphous, carbon, or diamond grains.

  16. Intracavity-pumped, cascaded AgGaSe₂ optical parametric oscillator tunable from 5.8 to 18 µm.

    PubMed

    Boyko, Andrey A; Marchev, Georgi M; Petrov, Valentin; Pasiskevicius, Valdas; Kolker, Dmitry B; Zukauskas, Andrius; Kostyukova, Nadezhda Y

    2015-12-28

    A AgGaSe2 nonlinear crystal placed in a coupled cavity is intracavity pumped by the ~1.85-µm signal pulses of a 1.064-µm pumped Rb:PPKTP doubly-resonant optical parametric oscillator (OPO) operating at a repetition rate of 100 Hz. Using two samples cut for type-I and II phase-matching, the overall idler tunability of the singly-resonant AgGeSe2 OPO covers an unprecedented spectral range from 5.8 to ~18 µm in the mid-IR. PMID:26832010

  17. ANNUS MIRABILIS. PHYSICS OF OUR DAYS: Geometry and Physics after 100 Years of Einstein's Relativity (5-8 April 2005)

    NASA Astrophysics Data System (ADS)

    Braginsky, Vladimir B.

    2005-06-01

    As part of the celebration of the World Year of Physics, the Conference "Geometry and Physics after 100 Years of Einstein's Relativity" was held in Golm, near Potsdam, Germany, on April 5-8, 2005. The Conference was organized by the Max Planck Institute for Gravitational Physics (also known as the Albert Einstein Institute), which is celebrating its 10th anniversary in 2005. Conference participants discussed progress made in theoretical and experimental research during the 100 years since the publication of Einstein's famous papers in 1905, the year which has gone down in history as 'Albert Einstein's ANNUS MIRABILIS'.

  18. Postoperative arrhythmias after cardiac surgery: incidence, risk factors, and therapeutic management.

    PubMed

    Peretto, Giovanni; Durante, Alessandro; Limite, Luca Rosario; Cianflone, Domenico

    2014-01-01

    Arrhythmias are a known complication after cardiac surgery and represent a major cause of morbidity, increased length of hospital stay, and economic costs. However, little is known about incidence, risk factors, and treatment of early postoperative arrhythmias. Both tachyarrhythmias and bradyarrhythmias can present in the postoperative period. In this setting, atrial fibrillation is the most common heart rhythm disorder. Postoperative atrial fibrillation is often self-limiting, but it may require anticoagulation therapy and either a rate or rhythm control strategy. However, ventricular arrhythmias and conduction disturbances can also occur. Sustained ventricular arrhythmias in the recovery period after cardiac surgery may warrant acute treatment and long-term preventive strategy in the absence of reversible causes. Transient bradyarrhythmias may be managed with temporary pacing wires placed at surgery, but significant and persistent atrioventricular block or sinus node dysfunction can occur with the need for permanent pacing. We provide a complete and updated review about mechanisms, risk factors, and treatment strategies for the main postoperative arrhythmias. PMID:24511410

  19. High prevalence of arrhythmias in elderly male athletes with a lifelong history of regular strenuous exercise

    PubMed Central

    Jensen-Urstad, K; Bouvier, F; Saltin, B; Jensen-Urstad, M

    1998-01-01

    Objective—To characterise cardiac arrhythmias and cardiac autonomic function in 11 elderly men (mean (SD) age 73.2 (2.8) years) with a lifelong history of regular very strenuous exercise. A control group of 12 healthy sedentary or moderately physically active men (74.5 (2.7) years) was also studied.
Design—48 hour ambulatory electrocardiograms were recorded. Cardiac autonomic function was estimated from power spectral analysis of heart rate variability. Maximal oxygen uptake during treadmill exercise testing was 2.91 (0.52) l (41 (7) ml/kg).
Results—Nine of 11 athletes had complex ventricular arrhythmias compared with five of 12 controls. Seven athletes but none of the controls had episodes of heart rate below 40 beats/min and two athletes had RR intervals longer than two seconds. Heart rate variability in the athletes was higher than in the controls. 
Conclusions—Elderly athletes with a lifelong training history seem to have more complex arrhythmias and profound bradyarrhythmias than do healthy elderly controls, which may increase the risk of sudden cardiac death. In contrast, the age related decrease in heart rate variability seems to be retarded, which has a positive prognostic value and may decrease the risk of life threatening ventricular arrhythmias.

 Keywords: arrhythmias;  heart rate variability;  athletes;  exercise;  elderly men PMID:9538309

  20. Electrical alternans during rest and exercise as predictors of vulnerability to ventricular arrhythmias

    NASA Technical Reports Server (NTRS)

    Estes, N. A. 3rd; Michaud, G.; Zipes, D. P.; El-Sherif, N.; Venditti, F. J.; Rosenbaum, D. S.; Albrecht, P.; Wang, P. J.; Cohen, R. J.

    1997-01-01

    This investigation was performed to evaluate the feasibility of detecting repolarization alternans with the heart rate elevated with a bicycle exercise protocol. Sensitive spectral signal-processing techniques are able to detect beat-to-beat alternation of the amplitude of the T wave, which is not visible on standard electrocardiogram. Previous animal and human investigations using atrial or ventricular pacing have demonstrated that T-wave alternans is a marker of vulnerability to ventricular arrhythmias. Using a spectral analysis technique incorporating noise reduction signal-processing software, we evaluated electrical alternans at rest and with the heart rate elevated during a bicycle exercise protocol. In this study we defined optimal criteria for electrical alternans to separate patients from those without inducible arrhythmias. Alternans and signal-averaged electrocardiographic results were compared with the results of vulnerability to ventricular arrhythmias as defined by induction of sustained ventricular tachycardia or fibrillation at electrophysiologic evaluation. In 27 patients alternans recorded at rest and with exercise had a sensitivity of 89%, specificity of 75%, and overall clinical accuracy of 80% (p <0.003). In this patient population the signal-averaged electrocardiogram was not a significant predictor of arrhythmia vulnerability. This is the first study to report that repolarization alternans can be detected with heart rate elevated with a bicycle exercise protocol. Alternans measured using this technique is an accurate predictor of arrhythmia inducibility.

  1. Torsade de pointes as a reperfusion arrhythmia following intravenous thrombolytic therapy.

    PubMed

    Tekur, Venkatesh

    2013-12-01

    Many types of cardiac arrhythmias have been noted following acute myocardial infarction. Polymorphic ventricular arrhythmias (polymorphic ventricular tachycardia and ventricular fibrillation) related to an acute myocardial infarction generally strike during the hyperacute phase, are clearly related to ischaemia and are not associated with a long QT interval time. Pause-dependent Torsade de pointes has been reported following acute myocardial infarction and this arrhythmia generally occurs 3-11 days after the onset of acute myocardial infarction and none has been reported during the hyperacute phase. Torsade de pointes - a specific ventricular tachycardia with specific characteristics has been described in hypokalemia, hypomagnesaemia, during Quinidine therapy, and while using phenothiazines and tricyclic antidepressants. It is reported following liquid protein diet, brady-arrhythmias [especially III° AV Block], sick-sinus syndromes. Torsade de pointes either pause-dependent or pause-independent occurring directly as a reperfusion arrhythmia during intravenous thrombolytic therapy has not been reported in the literature to the best of the authors knowledge. Here, an episode of Torsade de pointes as a direct consequence of reperfusion following thrombolytic therapy in a patient of acute myocardial infarction is described. PMID:24653589

  2. Arrhythmia Management in the Elderly-Implanted Cardioverter Defibrillators and Prevention of Sudden Death.

    PubMed

    Manian, Usha; Gula, Lorne J

    2016-09-01

    We present an overview of arrhythmia management in elderly patients as it pertains to implantable cardioverter defibrillator (ICD) therapy and prevention of sudden death. Treatment of arrhythmia in elderly patients is fraught with challenges pertaining to goals of care and patient frailty. With an ever increasing amount of technology available, realistic expectations of therapy need to balance quality and quantity of life. The ICD is an important treatment option for selected patients at risk of ventricular arrhythmia and sudden cardiac death. However, the incidence of sudden death as a percentage of all-cause mortality decreases with age. Studies have reported that 20% of elderly patients might die within 1 year of an episode of life-threatening ventricular arrhythmia, but most because of nonarrhythmic causes. This illustrates the 'sudden cardiac death paradox,' with a great proportion of death in elderly patients, even those at risk for ventricular arrhythmias, attributable to medical conditions that cannot be addressed by an ICD. We discuss current practices in ICD therapy in elderly patients, existing evidence from registries and clinical trials, approaches to risk stratification, and important ethical considerations. Although the decision on whether ICD insertion is appropriate in the elderly population remains an area of uncertainty from an evidence-based and ethical perspective, we offer insight on potential clinical and research strategies for this growing population. PMID:27568872

  3. Postoperative Arrhythmias after Cardiac Surgery: Incidence, Risk Factors, and Therapeutic Management

    PubMed Central

    Cianflone, Domenico

    2014-01-01

    Arrhythmias are a known complication after cardiac surgery and represent a major cause of morbidity, increased length of hospital stay, and economic costs. However, little is known about incidence, risk factors, and treatment of early postoperative arrhythmias. Both tachyarrhythmias and bradyarrhythmias can present in the postoperative period. In this setting, atrial fibrillation is the most common heart rhythm disorder. Postoperative atrial fibrillation is often self-limiting, but it may require anticoagulation therapy and either a rate or rhythm control strategy. However, ventricular arrhythmias and conduction disturbances can also occur. Sustained ventricular arrhythmias in the recovery period after cardiac surgery may warrant acute treatment and long-term preventive strategy in the absence of reversible causes. Transient bradyarrhythmias may be managed with temporary pacing wires placed at surgery, but significant and persistent atrioventricular block or sinus node dysfunction can occur with the need for permanent pacing. We provide a complete and updated review about mechanisms, risk factors, and treatment strategies for the main postoperative arrhythmias. PMID:24511410

  4. Electrical alternans during rest and exercise as predictors of vulnerability to ventricular arrhythmias.

    PubMed

    Estes, N A; Michaud, G; Zipes, D P; El-Sherif, N; Venditti, F J; Rosenbaum, D S; Albrecht, P; Wang, P J; Cohen, R J

    1997-11-15

    This investigation was performed to evaluate the feasibility of detecting repolarization alternans with the heart rate elevated with a bicycle exercise protocol. Sensitive spectral signal-processing techniques are able to detect beat-to-beat alternation of the amplitude of the T wave, which is not visible on standard electrocardiogram. Previous animal and human investigations using atrial or ventricular pacing have demonstrated that T-wave alternans is a marker of vulnerability to ventricular arrhythmias. Using a spectral analysis technique incorporating noise reduction signal-processing software, we evaluated electrical alternans at rest and with the heart rate elevated during a bicycle exercise protocol. In this study we defined optimal criteria for electrical alternans to separate patients from those without inducible arrhythmias. Alternans and signal-averaged electrocardiographic results were compared with the results of vulnerability to ventricular arrhythmias as defined by induction of sustained ventricular tachycardia or fibrillation at electrophysiologic evaluation. In 27 patients alternans recorded at rest and with exercise had a sensitivity of 89%, specificity of 75%, and overall clinical accuracy of 80% (p <0.003). In this patient population the signal-averaged electrocardiogram was not a significant predictor of arrhythmia vulnerability. This is the first study to report that repolarization alternans can be detected with heart rate elevated with a bicycle exercise protocol. Alternans measured using this technique is an accurate predictor of arrhythmia inducibility. PMID:9388105

  5. Palmitoylation by DHHC5/8 targets GRIP1 to dendritic endosomes to regulate AMPA-R trafficking

    PubMed Central

    Thomas, Gareth M.; Hayashi, Takashi; Chen, Chih-Ming; Chiu, Shu-Ling; Huganir, Richard L.

    2012-01-01

    Summary Palmitoylation, a key regulatory mechanism controlling protein targeting, is catalyzed by DHHC-family palmitoyl acyltransferases (PATs). Impaired PAT activity is linked to several neurodevelopmental and neuropsychiatric disorders, suggesting critical roles for palmitoylation in neuronal function. However, few substrates for specific PATs are known, and functional consequences of specific palmitoylation events are frequently uncharacterized. Here, we identify two related PATs, DHHC5 and DHHC8, as specific regulators of the PDZ domain protein GRIP1b. Binding, palmitoylation and dendritic targeting of GRIP1b require a DHHC5/8 PDZ ligand that is absent in all other PATs. Palmitoylated GRIP1b is targeted to trafficking endosomes, and may link endosomes to kinesin motors. Consistent with this trafficking role, GRIP1b's palmitoylation turnover rate approaches the highest of all reported proteins, and palmitoylation increases GRIP1b's ability to accelerate AMPA-R recycling. These findings identify the first neuronal DHHC5/8 substrate, define novel mechanisms controlling palmitoylation specificity, and suggest further links between dysregulated palmitoylation and neurodevelopmental / neuropsychiatric conditions. PMID:22325201

  6. Broadband carbon monoxide laser system operating in the wavelength range of 2.5 - 8.3 {mu}m

    SciTech Connect

    Andreev, Yu M; Ionin, Andrei A; Kinyaevsky, I O; Klimachev, Yu M; Kozlov, A Yu; Kotkov, A A; Lanskii, G V; Shaiduko, A V

    2013-02-28

    A two-cascade frequency conversion of CO-laser radiation is demonstrated in a single sample of a nonlinear ZnGeP{sub 2} crystal. The crystal is pumped by a repetitively pulsed cryogenic lowpressure CO laser operating on {approx}150 vibration - rotational transitions in the wavelength range 5.0 - 7.5 {mu}m, which corresponds to the frequency range of a half octave. In the first conversion cascade, generation of second harmonic and sum frequencies of various pairs of CO-laser radiation give {approx}350 emission lines in the wavelength range 2.5 - 3.7 {mu}m. In the second cascade, by mixing the radiation converted in the first cascade with the residual radiation of the CO laser we have obtained {approx}90 lines in the range 4.3 - 5.0 {mu}m and more than 80 lines in the range 7.5 - 8.3 {mu}m. Thus, using a single sample of the nonlinear ZnGeP{sub 2} crystal pumped by the radiation of a single CO laser we have produced a source of broadband (more than one and a half octaves) laser radiation, simultaneously operating at {approx}670 lines in the wavelength range 2.5 - 8.3 {mu}m. (lasers)

  7. Youth and Work: The Incidence of the Economic Situation on the Access of Young People to Education, Culture and Work. Report, Recommendations and Documents of a European Regional Meeting, Venice, 7-11 November, 1977.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France).

    This document contains materials from a Unesco European regional meeting held in Venice (November 7-11, 1977) to discuss the problem of youth unemployment. The final report of the meeting is composed of (1) a summary of the discussions on background and nature of the problem, remedies, action, education and training, creating jobs, quality of…

  8. Arrhythmia risk stratification of patients after myocardial infarction using personalized heart models.

    PubMed

    Arevalo, Hermenegild J; Vadakkumpadan, Fijoy; Guallar, Eliseo; Jebb, Alexander; Malamas, Peter; Wu, Katherine C; Trayanova, Natalia A

    2016-01-01

    Sudden cardiac death (SCD) from arrhythmias is a leading cause of mortality. For patients at high SCD risk, prophylactic insertion of implantable cardioverter defibrillators (ICDs) reduces mortality. Current approaches to identify patients at risk for arrhythmia are, however, of low sensitivity and specificity, which results in a low rate of appropriate ICD therapy. Here, we develop a personalized approach to assess SCD risk in post-infarction patients based on cardiac imaging and computational modelling. We construct personalized three-dimensional computer models of post-infarction hearts from patients' clinical magnetic resonance imaging data and assess the propensity of each model to develop arrhythmia. In a proof-of-concept retrospective study, the virtual heart test significantly outperformed several existing clinical metrics in predicting future arrhythmic events. The robust and non-invasive personalized virtual heart risk assessment may have the potential to prevent SCD and avoid unnecessary ICD implantations. PMID:27164184

  9. Current and future modalities of catheter ablation for the treatment of cardiac arrhythmias.

    PubMed

    Haines, D E

    1992-01-01

    Catheter ablation has proven to be a safe and effective treatment for a wide variety of cardiac arrhythmias. By destroying the critical zone of conductive tissue responsible for impulse generation or propagation, the arrhythmias may be cured. A variety of modalities of catheter ablation have been tested in the past decade. Initially, high energy direct current shocks delivered through a conventional electrode catheter were used. Now, use of radiofrequency energy as a power supply has resulted in higher efficacy and much improved safety of this technique. New approaches including low energy direct current shock ablation, microwave hyperthermic ablation, and laser photocoagulation are being tested, and may result in further refinement of nonsurgical curative therapy of arrhythmias. PMID:10147817

  10. Ubiquitous health monitoring and real-time cardiac arrhythmias detection: a case study.

    PubMed

    Li, Jian; Zhou, Haiying; Zuo, Decheng; Hou, Kun-Mean; De Vaulx, Christophe

    2014-01-01

    As the symptoms and signs of heart diseases that cause sudden cardiac death, cardiac arrhythmia has attracted great attention. Due to limitations in time and space, traditional approaches to cardiac arrhythmias detection fail to provide a real-time continuous monitoring and testing service applicable in different environmental conditions. Integrated with the latest technologies in ECG (electrocardiograph) analysis and medical care, the pervasive computing technology makes possible the ubiquitous cardiac care services, and thus brings about new technical challenges, especially in the formation of cardiac care architecture and realization of the real-time automatic ECG detection algorithm dedicated to care devices. In this paper, a ubiquitous cardiac care prototype system is presented with its architecture framework well elaborated. This prototype system has been tested and evaluated in all the clinical-/home-/outdoor-care modes with a satisfactory performance in providing real-time continuous cardiac arrhythmias monitoring service unlimitedly adaptable in time and space. PMID:24211993

  11. Next-generation sequencing for the diagnosis of cardiac arrhythmia syndromes.

    PubMed

    Lubitz, Steven A; Ellinor, Patrick T

    2015-05-01

    Inherited arrhythmia syndromes are collectively associated with substantial morbidity, yet our understanding of the genetic architecture of these conditions remains limited. Recent technological advances in DNA sequencing have led to the commercialization of genetic testing now widely available in clinical practice. In particular, next-generation sequencing allows the large-scale and rapid assessment of entire genomes. Although next-generation sequencing represents a major technological advance, it has introduced numerous challenges with respect to the interpretation of genetic variation and has opened a veritable floodgate of biological data of unknown clinical significance to practitioners. In this review, we discuss current genetic testing indications for inherited arrhythmia syndromes, broadly outline characteristics of next-generation sequencing techniques, and highlight challenges associated with such testing. We further summarize future directions that will be necessary to address to enable the widespread adoption of next-generation sequencing in the routine management of patients with inherited arrhythmia syndromes. PMID:25625719

  12. Arrhythmia risk stratification of patients after myocardial infarction using personalized heart models

    PubMed Central

    Arevalo, Hermenegild J.; Vadakkumpadan, Fijoy; Guallar, Eliseo; Jebb, Alexander; Malamas, Peter; Wu, Katherine C.; Trayanova, Natalia A.

    2016-01-01

    Sudden cardiac death (SCD) from arrhythmias is a leading cause of mortality. For patients at high SCD risk, prophylactic insertion of implantable cardioverter defibrillators (ICDs) reduces mortality. Current approaches to identify patients at risk for arrhythmia are, however, of low sensitivity and specificity, which results in a low rate of appropriate ICD therapy. Here, we develop a personalized approach to assess SCD risk in post-infarction patients based on cardiac imaging and computational modelling. We construct personalized three-dimensional computer models of post-infarction hearts from patients' clinical magnetic resonance imaging data and assess the propensity of each model to develop arrhythmia. In a proof-of-concept retrospective study, the virtual heart test significantly outperformed several existing clinical metrics in predicting future arrhythmic events. The robust and non-invasive personalized virtual heart risk assessment may have the potential to prevent SCD and avoid unnecessary ICD implantations. PMID:27164184

  13. A model for the generation of spontaneous yet predictable ventricular arrhythmias.

    PubMed

    Dennis, S C; Hearse, D J; Coltart, D J

    1981-01-01

    Development of an experimental preparation aided to investigate arrhythmogenic and antiarrhythmogenic factors influencing incidence of spontaneous and yet predictable ventricular arrhythmias is described. Using the isolated perfused guinea-pig heart and a system for quantitating rhythm disturbances based on computer-aided statistical analysis of beat-to-beat intervals, a number of factors influencing the incidence of rhythm disturbances were investigated. Manipulation of perfusate composition revealed that, after 'moderate' ischaemia, reperfusion arrhythmias were increased in the presence of noradrenaline and non-glucose fuels. Free fatty acids, unless in the presence of catecholamines, were not particularly arrhythmogenic. In contrast, the presence of pyruvate or lactate, endproduct inhibitors of glycolysis, significantly increased incidence of reflow rhythm disturbances. The dose-dependent arrhythmogenic effects of pyruvate and anti-arrhythmogenic effects of glucose support the thesis that inadequate glycolytic flux could be important in the development of arrhythmias. PMID:7238559

  14. Method and apparatus for the guided ablative therapy of fast ventricular arrhythmia

    NASA Technical Reports Server (NTRS)

    Cohen, Richard J. (Inventor); Barley, Maya (Inventor)

    2010-01-01

    Method and apparatus for guiding ablative therapy of abnormal biological electrical excitation. The excitation from the previous excitatory wave is significant at the beginning of the next excitation. In particular, it is designed for treatment of fast cardiac arrhythmias. Electrical signals are acquired from recording electrodes, and an inverse dipole method is used to identify the site of origin of an arrhythmia. The location of the tip of an ablation catheter is similarly localized from signals acquired from the recording electrodes while electrical pacing energy is delivered to the tip of the catheter close to or in contact with the cardiac tissue. The catheter tip is then guided to the site of origin of the arrhythmia, and ablative radio frequency energy is delivered to its tip to ablate the site.

  15. Calcium and voltage imaging in arrhythmia models by high-speed microscopy

    NASA Astrophysics Data System (ADS)

    de Mauro, C.; Cecchetti, C. A.; Alfieri, D.; Borile, G.; Urbani, A.; Mongillo, M.; Pavone, F. S.

    2014-03-01

    Alterations in intracellular cardiomyocyte calcium handling have a key role in initiating and sustaining arrhythmias. Arrhythmogenic calcium leak from sarcoplasmic reticulum (SR) can be attributed to all means by which calcium exits the SR store in an abnormal fashion. Abnormal SR calcium exit maymanifest as intracellular Ca2+ sparks and/or Ca2+ waves. Ca2+ signaling in arrhythmogenesis has been mainly studied in isolated cardiomyocytes and given that the extracellular matrix influences both Ca2+ and membrane potential dynamics in the intact heart and underlies environmentally mediated changes, understanding how Ca2+ and voltage are regulated in the intact heart will represent a tremendous advancement in the understanding of arrhythmogenic mechanisms. Using novel high-speed multiphoton microscopy techinques, such as multispot and random access, we investigated animal models with inherited and acquired arrhythmias to assess the role of Ca2+ and voltage signals as arrhythmia triggers in cell and subcellular components of the intact heart and correlate these with electrophysiology.

  16. A Real-Time PCR Assay Based on 5.8S rRNA Gene (5.8S rDNA) for Rapid Detection of Candida from Whole Blood Samples.

    PubMed

    Guo, Yi; Yang, Jing-Xian; Liang, Guo-Wei

    2016-06-01

    The prevalence of Candida in bloodstream infections (BSIs) has increased. To date, the identification of Candida in BSIs still mainly relies on blood culture and serological tests, but they have various limitations. Therefore, a real-time PCR assay for the detection of Candida from whole blood is presented. The unique primers/probe system was designed on 5.8S rRNA gene (5.8S rDNA) of Candida genus. The analytical sensitivity was determined by numbers of positive PCRs in 12 repetitions. At the concentration of 10(1) CFU/ml blood, positive PCR rates of 100 % were obtained for C. albicans, C. parapsilosis, C. tropicalis, and C. krusei. The detection rate for C. glabrata was 75 % at 10(1) CFU/ml blood. The reaction specificity was 100 % when evaluating the assay using DNA samples from clinical isolates and human blood. The maximum CVs of intra-assay and inter-assay for the detection limit were 1.22 and 2.22 %, respectively. To assess the clinical applicability, 328 blood samples from 82 patients were prospectively tested and real-time PCR results were compared with results from blood culture. Diagnostic sensitivity of the PCR was 100 % using as gold standard blood culture, and specificity was 98.4 %. Our data suggest that the developed assay can be used in clinical laboratories as an accurate and rapid screening test for the Candida from whole blood. Although further evaluation is warranted, our assay holds promise for earlier diagnosis of candidemia. PMID:26687075

  17. Arrhythmia recognition and classification using combined linear and nonlinear features of ECG signals.

    PubMed

    Elhaj, Fatin A; Salim, Naomie; Harris, Arief R; Swee, Tan Tian; Ahmed, Taqwa

    2016-04-01

    Arrhythmia is a cardiac condition caused by abnormal electrical activity of the heart, and an electrocardiogram (ECG) is the non-invasive method used to detect arrhythmias or heart abnormalities. Due to the presence of noise, the non-stationary nature of the ECG signal (i.e. the changing morphology of the ECG signal with respect to time) and the irregularity of the heartbeat, physicians face difficulties in the diagnosis of arrhythmias. The computer-aided analysis of ECG results assists physicians to detect cardiovascular diseases. The development of many existing arrhythmia systems has depended on the findings from linear experiments on ECG data which achieve high performance on noise-free data. However, nonlinear experiments characterize the ECG signal more effectively sense, extract hidden information in the ECG signal, and achieve good performance under noisy conditions. This paper investigates the representation ability of linear and nonlinear features and proposes a combination of such features in order to improve the classification of ECG data. In this study, five types of beat classes of arrhythmia as recommended by the Association for Advancement of Medical Instrumentation are analyzed: non-ectopic beats (N), supra-ventricular ectopic beats (S), ventricular ectopic beats (V), fusion beats (F) and unclassifiable and paced beats (U). The characterization ability of nonlinear features such as high order statistics and cumulants and nonlinear feature reduction methods such as independent component analysis are combined with linear features, namely, the principal component analysis of discrete wavelet transform coefficients. The features are tested for their ability to differentiate different classes of data using different classifiers, namely, the support vector machine and neural network methods with tenfold cross-validation. Our proposed method is able to classify the N, S, V, F and U arrhythmia classes with high accuracy (98.91%) using a combined support

  18. Risk of Ventricular Arrhythmia with Citalopram and Escitalopram: A Population-Based Study

    PubMed Central

    Qirjazi, Elena; McArthur, Eric; Nash, Danielle M.; Dixon, Stephanie N.; Weir, Matthew A.; Vasudev, Akshya; Jandoc, Racquel; Gula, Lorne J.; Oliver, Matthew J.; Wald, Ron; Garg, Amit X.

    2016-01-01

    Background The risk of ventricular arrhythmia with citalopram and escitalopram is controversial. In this study we investigated the association between these two drugs and the risk of ventricular arrhythmia. Methods We conducted a population-based retrospective cohort study of older adults (mean age 76 years) from 2002 to 2012 in Ontario, Canada, newly prescribed citalopram (n = 137 701) or escitalopram (n = 38 436), compared to those prescribed referent antidepressants sertraline or paroxetine (n = 96 620). After inverse probability of treatment weighting using a propensity score, the baseline characteristics of the comparison groups were similar. The primary outcome was a hospital encounter with ventricular arrhythmia within 90 days of a new prescription, assessed using hospital diagnostic codes. The secondary outcome was all-cause mortality within 90 days. Results Citalopram was associated with a higher risk of a hospital encounter with ventricular arrhythmia compared with referent antidepressants (0.06% vs. 0.04%, relative risk [RR] 1.53, 95% confidence intervals [CI]1.03 to 2.29), and a higher risk of mortality (3.49% vs. 3.12%, RR 1.12, 95% CI 1.06 to 1.18). Escitalopram was not associated with a higher risk of ventricular arrhythmia compared with the referent antidepressants (0.03% vs. 0.04%, RR 0.84, 95% CI 0.42 to 1.68), but was associated with a higher risk of mortality (2.86% vs. 2.63%, RR 1.09, 95% CI 1.01 to 1.18). Conclusion Among older adults, initiation of citalopram compared to two referent antidepressants was associated with a small but statistically significant increase in the 90-day risk of a hospital encounter for ventricular arrhythmia. PMID:27513855

  19. A 3-month long operational implementation of an ensemble prediction system of storm surge for the city of Venice

    NASA Astrophysics Data System (ADS)

    Mel, Riccardo; Lionello, Piero

    2014-05-01

    Advantages of an ensemble prediction forecast (EPF) technique that has been used for sea level (SL) prediction at the Northern Adriatic coast are investigated. The aims is to explore whether EPF is more precise than the traditional Deterministic Forecast (DF) and the value of the added information, mainly on forecast uncertainty. Improving the SL forecast for the city of Venice is of paramount importance for the management and maintenance of this historical city and for operating the movable barriers that are presently being built for its protection. The operational practice is simulated for three months from 1st October to 31st December 2010. The EPF is based on the HYPSE model, which is a standard single-layer nonlinear shallow water model, whose equations are derived from the depth averaged momentum equations and predicts the SL. A description of the model is available in the scientific literature. Forcing of HYPSE are provided by three different sets of 3-hourly ECMWF 10m-wind and MSLP fields: the high resolution meteorological forecast (which is used for the deterministic SL forecast, DF), the control run forecast (CRF, that differs from the DF forecast only for it lower meteorological fields resolution) and the 50 ensemble members of the ECMWF EPS (which are used for the SL-EPS. The resolution of DF fields is T1279 and resolution of both CRF and ECMWF EPS fields is T639 resolution. The 10m wind and MSLP fields have been downloaded at 0.125degs (DF) and 0.25degs(CRF and EPS) and linearly interpolated to the HYPSE grid (which is the same for all simulations). The version of HYPSE used in the SR EPS uses a rectangular mesh grid of variable size, which has the minimum grid step (0.03 degrees) in the northern part of the Adriatic Sea, from where grid step increases with a 1.01 factor in both latitude and longitude (In practice, resolution varies in the range from 3.3 to 7km). Results are analyzed considering the EPS spread, the rms of the simulations, the Brier

  20. Assessment of sediment toxicity in the Lagoon of Venice (Italy) using a multi-species set of bioassays.

    PubMed

    Picone, Marco; Bergamin, Martina; Losso, Chiara; Delaney, Eugenia; Arizzi Novelli, Alessandra; Ghirardini, Annamaria Volpi

    2016-01-01

    Within the framework of a Weight of Evidence (WoE) approach, a set of four toxicity bioassays involving the amphipod Corophium volutator (10 d lethality test on whole sediment), the sea urchin Paracentrotus lividus (fertilization and embryo toxicity tests on elutriate) and the pacific oyster Crassostrea gigas (embryo toxicity test on elutriate) was applied to sediments from 10 sampling sites of the Venice Lagoon (Italy). Sediments were collected during three campaigns carried out in May 2004 (spring campaign), October 2004 (autumn campaign) and February 2005 (winter campaign). Toxicity tests were performed on all sediment samples. Sediment grain-size and chemistry were measured during spring and autumn campaigns. This research investigated (i) the ability of toxicity tests in discriminating among sites with different contamination level, (ii) the occurrence of a gradient of effect among sampling sites, (iii) the possible correlation among toxicity tests, sediment chemistry, grain size and organic carbon, and (iv) the possible occurrence of toxicity seasonal variability. Sediment contamination levels were from low to moderate. No acute toxicity toward amphipods was observed, while sea urchin fertilization was affected only in few sites in just a single campaign. Short-term effects on larval development of sea urchin and oyster evidenced a clear spatial trend among sites, with increasing effects along the axis connecting the sea-inlets with the industrial area. The set of bioassays allowed the identification of a spatial gradient of effect, with decreasing toxicity from the industrial area toward the sea-inlets. Multivariate data analysis showed that the malformations of oyster embryos were significantly correlated to the industrial contamination (metals, polynuclear aromatic hydrocarbons, hexachlorobenzene and polychlorinated biphenyls), while sea urchin development to sediment concentrations of As, Cr and organic carbon. Both embryo toxicity tests were

  1. Concentration and speciation of plutonium, americium, uranium, thorium, potassium and 137Cs in a venice canal sediment sample

    NASA Astrophysics Data System (ADS)

    Testa, C.; Desideri, D.; Guerra, F.; Meli, M. A.; Roselli, C.; Degetto, S.

    1999-01-01

    A sequential extraction method consisting of six operationally-defined fractions has been developed for determining the geochemical partitioning of natural (U, Th, 40K) and antropogenic (Pu, Am, 137Cs) radionuclides in a 40 50 cm deep sediment sample collected in a Venice canal. Extraction chromatography with Microthene-TOPO (U, Th), Microthene-TNOA (Pu) and Microthene-HDEHP (Am) column was used for the chemical separation of a single radionuclide; the final recoveries were calculated by adding 236U, 229Th, 242Pu and 243Am as the yield tracers. After electrodeposition the alpha spectrometry was carried out. 137Cs and 40K were measured by gamma spectrometry. The total concentrations in the wet sample (Bq/kgd), obtained by a complete disgregation of the matrix by wet and dry treatment, were the following: 239+240Pu=1.03±0.07, 238Pu=0.022±0.005, 241Am=0.337±0.027, 137Cs=9.78±0.78, 238U=28.84±1.62, 232Th=21.42±1.93, 40K=376.05±12.78. The mean ratio 238Pu/239+240Pu (0.02) shows a contamination due essentially to fall-out and U and Th alpha spectra indicate the natural origin of two elements. The absence of 134Cs in the sample proves that at 40 50 cm depth the sediment was not affected by the Chernobyl fall-out. As far as the speciation is concerned the following fractions were considered: water soluble, carbonates, Fe-Mn oxides, organic matter, acid soluble, residue. Pu (˜67%) an Am (˜95%) were present principally in the carbonate fraction; U was more distributed and about 30% and 45% appeared in the carbonate fraction and in the residue respectively; the majority of Th was present in the residue (˜60%); 40K was totally present in the residue; finally 137Cs was found mostly in the acid soluble fraction (˜53%) and in the residue (˜47%). Some stable elements (Fe, Mn, Al, Ti, Ca, Pb, Ba) were also determined in the different fractions to get more information about the chemical association of the single radionuclides.

  2. Concentration and speciation of plutonium, americium, uranium, thorium, potassium and 137Cs in a venice canal sediment sample

    NASA Astrophysics Data System (ADS)

    Testa, C.; Desideri, D.; Guerra, F.; Meli, M. A.; Roselli, C.; Degetto, S.

    1999-01-01

    A sequential extraction method consisting of six operationally-defined fractions has been developed for determining the geochemical partitioning of natural (U, Th, 40K) and antropogenic (Pu, Am, 137Cs) radionuclides in a 40-50 cm deep sediment sample collected in a Venice canal. Extraction chromatography with Microthene-TOPO (U, Th), Microthene-TNOA (Pu) and Microthene-HDEHP (Am) column was used for the chemical separation of a single radionuclide; the final recoveries were calculated by adding 236U, 229Th, 242Pu and 243Am as the yield tracers. After electrodeposition the alpha spectrometry was carried out. 137Cs and 40K were measured by gamma spectrometry. The total concentrations in the wet sample (Bq/kgd), obtained by a complete disgregation of the matrix by wet and dry treatment, were the following: 239+240Pu=1.03±0.07, 238Pu=0.022±0.005, 241Am=0.337±0.027, 137Cs=9.78±0.78, 238U=28.84±1.62, 232Th=21.42±1.93, 40K=376.05±12.78. The mean ratio 238Pu/239+240Pu (0.02) shows a contamination due essentially to fall-out and U and Th alpha spectra indicate the natural origin of two elements. The absence of 134Cs in the sample proves that at 40-50 cm depth the sediment was not affected by the Chernobyl fall-out. As far as the speciation is concerned the following fractions were considered: water soluble, carbonates, Fe-Mn oxides, organic matter, acid soluble, residue. Pu (˜67%) an Am (˜95%) were present principally in the carbonate fraction; U was more distributed and about 30% and 45% appeared in the carbonate fraction and in the residue respectively; the majority of Th was present in the residue (˜60%); 40K was totally present in the residue; finally 137Cs was found mostly in the acid soluble fraction (˜53%) and in the residue (˜47%). Some stable elements (Fe, Mn, Al, Ti, Ca, Pb, Ba) were also determined in the different fractions to get more information about the chemical association of the single radionuclides.

  3. Computational rabbit models to investigate the initiation, perpetuation, and termination of ventricular arrhythmia.

    PubMed

    Arevalo, Hermenegild J; Boyle, Patrick M; Trayanova, Natalia A

    2016-07-01

    Current understanding of cardiac electrophysiology has been greatly aided by computational work performed using rabbit ventricular models. This article reviews the contributions of multiscale models of rabbit ventricles in understanding cardiac arrhythmia mechanisms. This review will provide an overview of multiscale modeling of the rabbit ventricles. It will then highlight works that provide insights into the role of the conduction system, complex geometric structures, and heterogeneous cellular electrophysiology in diseased and healthy rabbit hearts to the initiation and maintenance of ventricular arrhythmia. Finally, it will provide an overview on the contributions of rabbit ventricular modeling on understanding the mechanisms underlying shock-induced defibrillation. PMID:27334789

  4. The role of viruses, inflammation and myocardial macrophages in the development of idiopathic arrhythmia

    NASA Astrophysics Data System (ADS)

    Rebenkova, M.; Gombozhapova, A.; Shurupov, V.; Rogovskaya, Yu.; Botalov, R.; Ryabov, V.; Popov, S.; Karpov, R.

    2015-11-01

    We studied viral antigens, inflammation, and macrophages in the endomyocardial biopsies of patients with idiopathic arrhythmias. Immunohistological study was performed to identify the antigens of cardiotropic viruses and the types of lymphocytes and macrophages. We observed the presence of viral antigens in the myocardium of patients with and without histological criteria of myocarditis. Heart failure and ventricular arrhythmias were associated with small focal infiltration of the myocardium with macrophages. The presence of viral antigens in the myocardium was associated with fewer number of myocardial M2 macrophages. Severity of myocardial interstitial fibrosis correlated with small-focal infiltration of M2 macrophages.

  5. Analysis of electrolyte abnormalities and the mechanisms leading to arrhythmias in heart failure. A literature review.

    PubMed

    Urso, C; Canino, B; Brucculeri, S; Firenze, A; Caimi, G

    2016-01-01

    About 50% of deaths from heart failure (HF) are sudden, presumably referable to arrhythmias. Electrolyte and acid-base abnormalities are a frequent and potentially dangerous complication in HF patients. Their incidence is almost always correlated with the severity of cardiac dysfunction; furthermore leading to arrhythmias, these imbalances are associated with a poor prognosis. The frequency of ventricular ectopic beats and sudden cardiac death correlate with both plasma and whole body levels of potassium, especially in alkalemia. The early recognition of these alterations and the knowledge of the pathophysiological mechanisms are useful for the management of these HF patients. PMID:27598028

  6. Ventricular arrhythmias induced by long-term use of ephedrine in two competitive athletes.

    PubMed

    Casella, Michela; Dello Russo, Antonio; Izzo, Gennaro; Pieroni, Maurizio; Andreini, Daniele; Russo, Eleonora; Colombo, Daniele; Bologna, Fabrizio; Bolognese, Leonardo; Zeppilli, Paolo; Tondo, Claudio

    2015-03-01

    Ephedrine is a sympathomimetic substance used by sportsmen as a doping substance because of its stimulating and slimming effects. We report two cases of ventricular arrhythmias induced by abuse of ephedrine in two competitive athletes. Endomyocardial biopsies guided by electroanatomic mapping revealed contraction-band necrosis, a myocardial injury frequently observed in cases of catecholamine excess. Our cases suggest that long-term abuse of ephedrine may result in myocardial damage, and that these structural alterations may promote areas of slow conduction favoring re-entrant ventricular tachyarrhythmias and a long-lasting risk of ventricular arrhythmias. PMID:24390726

  7. Non-Invasive Assessment of Susceptibility to Ventricular Arrhythmias During Simulated Microgravity

    NASA Technical Reports Server (NTRS)

    Cohen, Richard J.

    1999-01-01

    The Cardiovascular Alterations Team is currently conducting studies to determine what alterations in hemodynamic regulation result from sixteen days of simulated microgravity exposure in normal human subjects. In this project we make additional measurements on these same study subjects in order to determine whether there is an increase in susceptibility to ventricular arrhythmias resulting from simulated microgravity exposure. Numerous anecdotal and documented reports from the past 30 years suggest that the incidence of ventricular arrhythmias among astronauts is increased during space flight. For example, documented runs of ventricular tachycardia have been recorded from crew members of Skylab and Mir, there was much attention given by the lay press to Mir Commander Vasily Tslbliyev's complaints of heart rhythm irregularities in July of 1997, and cardiovascular mechanisms may have been causal in the recent death of an experimental primate shortly after return from space. In 1986, a Mir cosmonaut, Alexander Laveikin, was brought home and replaced with an alternate cosmonaut as a result of cardiac dysrhythmias that began during extravehicular activity. Furthermore, at a joint NASA/NSBRI workshop held in January 1998, cardiac arrhythmias were identified as the highest priority cardiovascular risk to a human Mars mission. Despite the evidence for the risk of a potentially lethal arrhythmia resulting from microgravity exposure, the effects of space flight and the associated physiologic stresses on cardiac conduction processes are not known, and an increase in cardiac susceptibility to arrhythmias has never been quantified. In this project, we are determining whether simulated space flight increases the risk of developing life-threatening heart rhythm disturbances such as sustained ventricular tachycardia (defined as ventricular tachycardia lasting at least 30 seconds or resulting in hemodynamic collapse) and ventricular fibrillation. We are obtaining measures of

  8. Loop mediated isothermal amplification of 5.8S rDNA for specific detection of Tritrichomonas foetus.

    PubMed

    Oyhenart, Jorge; Martínez, Florencia; Ramírez, Rosana; Fort, Marcelo; Breccia, Javier D

    2013-03-31

    Tritrichomonas foetus is the causative agent of bovine trichomonosis, a sexually transmitted disease leading to infertility and abortion. A test based on loop mediated isothermal amplification (LAMP) targeting the 5.8S rDNA subunit was designed for the specific identification of T. foetus. The LAMP assay was validated using 28 T. foetus and 35 non-T. foetus trichomonads strains. It did not exhibit cross-reaction with closely related parasites commonly found in smegma cultures like Tetratrichomonas spp. and Pentatrichomonas hominis. Bovine smegma did not show interferences for the detection of the parasite and, the sensitivity of the method (4×10(3) CFU/mL, approximately 10 cells/reaction) was slightly higher than that found for PCR amplification with TFR3 and TFR4 primers. The LAMP approach has potential applications for diagnosis and control of T. foetus and, practical use for low skill operators in rural areas. PMID:23265811

  9. Experimental Investigation of the Low-Speed Aerodynamic Characteristics of a 5.8-Percent Scale Hybrid Wing Body Configuration

    NASA Technical Reports Server (NTRS)

    Gatlin, Gregory M.; Vicroy, Dan D.; Carter, Melissa B.

    2012-01-01

    A low-speed experimental investigation has been conducted on a 5.8-percent scale Hybrid Wing Body configuration in the NASA Langley 14- by 22-Foot Subsonic Tunnel. This Hybrid Wing Body (HWB) configuration was designed with specific intention to support the NASA Environmentally Responsible Aviation (ERA) Project goals of reduced noise, emissions, and fuel burn. This HWB configuration incorporates twin, podded nacelles mounted on the vehicle upper surface between twin vertical tails. Low-speed aerodynamic characteristics were assessed through the acquisition of force and moment, surface pressure, and flow visualization data. Longitudinal and lateral-directional characteristics were investigated on this multi-component model. The effects of a drooped leading edge, longitudinal flow-through nacelle location, vertical tail shape and position, elevon deflection, and rudder deflection have been studied. The basic configuration aerodynamics, as well as the effects of these configuration variations, are presented in this paper.

  10. Structural and dynamical characterization of the Miz-1 zinc fingers 5-8 by solution-state NMR.

    PubMed

    Bernard, David; Bédard, Mikaël; Bilodeau, Josée; Lavigne, Pierre

    2013-10-01

    Myc-interacting zinc finger protein-1 (Miz-1) is a BTB/POZ transcription factor that activates the transcription of cytostatic genes, such as p15(INK4B) or p21(CIP1). The C-terminus of Miz-1 contains 13 consensus C2H2 zinc finger domains (ZF). ZFs 1-4 have been shown to interact with SMAD3/4, while the remaining ZFs are expected to bind the promoters of target genes. We have noted unusual features in ZF 5 and the linker between ZFs 5 and 6. Indeed, a glutamate is found instead of the conserved basic residue two positions before the second zinc-coordinating histidine on the ZF 5 helix, and the linker sequence is DTDKE in place of the classical TGEKP sequence. In a canonical ββα fold, such unusual primary structure elements should cause severe electrostatic repulsions. In this context, we have characterized the structure and the dynamics of a Miz-1 construct comprising ZFs 5-8 (Miz 5-8) by solution-state NMR. Whilst ZFs 5, 7 and 8 were shown to adopt the classical ββα fold for C2H2 ZFs, the number of long-range NOEs was insufficient to define a classical fold for ZF 6. We show by using (15)N-relaxation dispersion experiments that this lack of NOEs is due to the presence of extensive motions on the μs-ms timescale. Since this negatively charged region would have to be located near the phosphodiester backbone in a DNA complex, we propose that in addition to promoting conformational searches, it could serve as a hinge region to keep ZFs 1-4 away from DNA. PMID:23975355

  11. Relationship of ventricular arrhythmias to the angiographically and scintigraphically estimated extent of ventricular damage late after myocardial infarction

    SciTech Connect

    Huikuri, H.V.; Korhonen, U.R.; Linnaluoto, M.K.; Takkunen, J.T.

    1987-03-01

    In order to study the quantitative relationship of ventricular arrhythmias to myocardial damage and ischemia, 61 patients with a previous myocardial infarction (at least 6 months previously) were studied by 24-hour ambulatory ECG monitoring, cardiac catheterization, and thallium-201 scintigraphy. Thirty-five patients (57%) had no ectopic beats or only infrequent, unifocal ones and 26 patients (43%) had complex ventricular arrhythmias. Left ventricular function was lower in the latter, but the number of diseased vessels did not differ in the two groups. The reduction of thallium activity in the infarct area was more marked in patients with complex arrhythmias. Multiple thallium defects were not more common in arrhythmia patients, however. These data support the view that complex ventricular arrhythmias are more closely related to the severity of ventricular damage than the presence of myocardial ischemia remote to the area of previous infarction.

  12. The effect of uraemia on the duration of arrhythmias in the context of cardioprotective ischaemic conditioning strategies

    PubMed Central

    McCafferty, Kieran; Byrne, Conor J; Kieswich, Julius; Raftery, Martin; Thiemermann, Christoph; Yaqoob, Muhammad M

    2014-01-01

    Background Sudden cardiac death is a leading cause of death in patients with chronic kidney disease and end stage renal disease. Ischaemic conditioning strategies confer profound myocardial protection and, in the absence of uraemia, have been reported to reduce myocardial dysrhythmias. Recent data confirms that ischaemic conditioning can protect the uraemic heart. However, the effect of uraemia on myocardial arrhythmogenesis in the context of ischaemia-reperfusion injury and whether ischaemic conditioning can modulate this is unknown. Objective We investigated the effect of underling chronic uraemia on the duration of arrhythmias in the context of cardioprotective ischaemic conditioning strategies. Methods We examined the effect of chronic uraemia on arrhythmias occurring in the context of myocardial ischaemia-reperfusion injury and the ability of ischaemic preconditioning (IPC), remote ischaemic preconditioning (RIPC) and ischaemic postconditioning (iPOST) to suppress arrhythmogenesis in uraemic and non-uraemic animals. Results IPC led to a reduction in the frequency and duration of arrhythmias occurring during ischaemia and reperfusion. Neither RIPC nor iPOST affected the duration or frequency of ischaemic or reperfusion arrhythmias. Underlying uraemia did not alter the frequency or duration of ischaemic arrhythmias in any of the experiments however it was associated with a reduction in reperfusion arrhythmia duration in the IPC and iPOST experiments. Conclusions These studies demonstrate that underlying chronic uraemia does not reduce the threshold for arrhythmia timing or duration resulting from myocardial ischaemia-reperfusion and underlying uraemia did not alter the effects of these cardioprotective ischaemic conditioning strategies in the context of arrhythmia duration. Summary This novel work in a rodent model of chronic uraemia establishes that underlying uraemia does not increase the susceptibility to myocardial ischaemia-reperfusion induced arrhythmias

  13. Morphodynamic evolution and stratal architecture of tidal meander bends through geophysical investigations and numerical modelling: inferences from the Venice Lagoon (Italy)

    NASA Astrophysics Data System (ADS)

    Brivio, Lara; Ghinassi, Massimilano; D'Alpaos, Andrea; Finotello, Alvise; Carniello, Luca; Marani, Marco

    2014-05-01

    Keywords: tidal meanders, stratal architecture, morphodynamics, mathematical modeling, Venice Lagoon. Although meanders are ubiquitous features of the tidal landscape, very few papers have analyzed their morphodynamic evolution or internal architecture, which is commonly analyzed basing on facies models developed for fluvial meander bend deposits. Towards the goal of providing new insight into the morphodynamic evolution of tidal meanders, together with high-resolution facies models, we analyzed a tidal point bar located in the Northern part of the Venice Lagoon (Italy), the largest Mediterranean brackish water body, characterized by an area of about 550 km2 and subjected to a semidiurnal tidal regime with an average tidal range of about 1 m and peak tidal amplitudes of about 0.75 m. High-resolution spatial data were acquired through the use of a sub-bottom profiler along a meander bend in the Northern part of the Venice lagoon. Sub-bottom profiles were collected along transects oriented both parallel and transverse to the main channel axis, and interpreted through a specific 3D modeling software. In the study segment, the channel is 100 m wide and 3 - 5 m deep and defines a bend with a curvature radius of about 200 m. Geophysical data highlight the presence of two laterally extensive key surfaces, which divide the channel deposits into three sedimentary units (up to 6.0, 4.0 and 3.5 m thick, respectively), associated with three main depositional stages of meander bend evolution. All these stages emphasize the occurrence of an ebb - dominated transport, especially in the first and in the second ones. The first stage is associated with development of point-bar deposits and is characterized by lateral accreting beds dipping toward the channel thalweg at about 10-20°. The second stage is associated with deposition in the landward side of the meander bend, where both aggradation and lateral accretion are documented. The third stage is characterized by accumulation of

  14. Simulation of Cardiac Arrhythmias Using a 2D Heterogeneous Whole Heart Model

    PubMed Central

    Balakrishnan, Minimol; Chakravarthy, V. Srinivasa; Guhathakurta, Soma

    2015-01-01

    Simulation studies of cardiac arrhythmias at the whole heart level with electrocardiogram (ECG) gives an understanding of how the underlying cell and tissue level changes manifest as rhythm disturbances in the ECG. We present a 2D whole heart model (WHM2D) which can accommodate variations at the cellular level and can generate the ECG waveform. It is shown that, by varying cellular-level parameters like the gap junction conductance (GJC), excitability, action potential duration (APD) and frequency of oscillations of the auto-rhythmic cell in WHM2D a large variety of cardiac arrhythmias can be generated including sinus tachycardia, sinus bradycardia, sinus arrhythmia, sinus pause, junctional rhythm, Wolf Parkinson White syndrome and all types of AV conduction blocks. WHM2D includes key components of the electrical conduction system of the heart like the SA (Sino atrial) node cells, fast conducting intranodal pathways, slow conducting atriovenctricular (AV) node, bundle of His cells, Purkinje network, atrial, and ventricular myocardial cells. SA nodal cells, AV nodal cells, bundle of His cells, and Purkinje cells are represented by the Fitzhugh-Nagumo (FN) model which is a reduced model of the Hodgkin-Huxley neuron model. The atrial and ventricular myocardial cells are modeled by the Aliev-Panfilov (AP) two-variable model proposed for cardiac excitation. WHM2D can prove to be a valuable clinical tool for understanding cardiac arrhythmias. PMID:26733873

  15. Central Sympathetic Inhibition: a Neglected Approach for Treatment of Cardiac Arrhythmias?

    PubMed

    Cagnoni, Francesca; Destro, Maurizio; Bontempelli, Erika; Locatelli, Giovanni; Hering, Dagmara; Schlaich, Markus P

    2016-02-01

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Overactivation of the sympathetic nervous system (SNS) plays an important role in the pathogenesis of comorbidities related to AF such as hypertension, congestive heart failure, obesity, insulin resistance, and obstructive sleep apnea. Methods that reduce sympathetic drive, such as centrally acting sympatho-inhibitory agents, have been shown to reduce the incidence of spontaneous or induced atrial arrhythmias, suggesting that neuromodulation may be helpful in controlling AF. Moxonidine acts centrally to reduce activity of the SNS, and clinical trials indicate that this is associated with a decreased AF burden in hypertensive patients with paroxysmal AF and reduced post-ablation recurrence of AF in patients with hypertension who underwent pulmonary vein isolation (PVI). Furthermore, device-based approaches to reduce sympathetic drive, such as renal denervation, have yielded promising results in the prevention and treatment of cardiac arrhythmias. In light of these recent findings, targeting elevated sympathetic drive with either pharmacological or device-based approaches has become a focus of clinical research. Here, we review the data currently available to explore the potential utility of sympatho-inhibitory therapies in the prevention and treatment of cardiac arrhythmias. PMID:26781253

  16. Arrhythmias, elicited by catecholamines and serotonin, vanish in human chronic atrial fibrillation

    PubMed Central

    Christ, Torsten; Rozmaritsa, Nadiia; Engel, Andreas; Berk, Emanuel; Knaut, Michael; Metzner, Katharina; Canteras, Manuel; Ravens, Ursula; Kaumann, Alberto

    2014-01-01

    Atrial fibrillation (AF) is the most common heart rhythm disorder. Transient postoperative AF can be elicited by high sympathetic nervous system activity. Catecholamines and serotonin cause arrhythmias in atrial trabeculae from patients with sinus rhythm (SR), but whether these arrhythmias occur in patients with chronic AF is unknown. We compared the incidence of arrhythmic contractions caused by norepinephrine, epinephrine, serotonin, and forskolin in atrial trabeculae from patients with SR and patients with AF. In the patients with AF, arrhythmias were markedly reduced for the agonists and abolished for forskolin, whereas maximum inotropic responses were markedly blunted only for serotonin. Serotonin and forskolin produced spontaneous diastolic Ca2+ releases in atrial myocytes from the patients with SR that were abolished or reduced in myocytes from the patients with AF. For matching L-type Ca2+-current (ICa,L) responses, serotonin required and produced ∼100-fold less cAMP/PKA at the Ca2+ channel domain compared with the catecholamines and forskolin. Norepinephrine-evoked ICa,L responses were decreased by inhibition of Ca2+/calmodulin-dependent kinase II (CaMKII) in myocytes from patients with SR, but not in those from patients with AF. Agonist-evoked phosphorylation by CaMKII at phospholamban (Thr-17), but not of ryanodine2 (Ser-2814), was reduced in trabeculae from patients with AF. The decreased CaMKII activity may contribute to the blunting of agonist-evoked arrhythmias in the atrial myocardium of patients with AF. PMID:25024212

  17. Considerations of current methods for drug selection in treating malignant ventricular arrhythmias.

    PubMed

    Lown, B; Podrid, P J; Graboys, T B; Lampert, S; Blatt, C

    1987-10-16

    The current burgeoning interest in antiarrhythmic drugs derives in large measure from a growing concern with the enormous problem of sudden cardiac death. Until the latter half of the twentieth century, beyond a nodding acknowledgment of its massive prevalence, this syndrome received but scant attention from the medical profession. In the early 1960s a number of insights changed perceptions as well as practice. These related to 4 postulates: (1) sudden cardiac death, in the majority of victims, was due to ventricular tachyarrhythmias either initiated by or culminating rapidly in ventricular fibrillation; (2) the lethal arrhythmia was not the consequence of irreversible pathomorphologic impairment of the contractile apparatus, but rather the expression of an electrophysiologic derangement; (3) the triggering of ventricular fibrillation was the result of an electrical accident both reversible as well as preventable; (4) the potential victim was identifiable either by the presence of certain grades of ventricular ectopic activity or by exposure of repetitive ectopic activity or by exposure of repetitive ventricular arrhythmias by electrophysiologic techniques. The innovations that have led to these insights and their consequences have been numerous and continuous. Among these are direct current defibrillation, cardioversion, coronary care units, bystander-initiated cardiopulmonary resuscitation, ambulatory electrocardiographic monitoring and exercise stress testing for exposing ventricular arrhythmias, electrophysiologic provocative testing and mapping techniques, overdrive programmable pacemakers as well as implantable defibrillators and cardioverters, and surgical, electrical and laser techniques for ablating the nidus or interrupting the pathways of the arrhythmias. PMID:3661427

  18. Weather and triggering of ventricular arrhythmias in patients with implantable cardioverter-defibrillators.

    PubMed

    Nguyen, Jennifer L; Laden, Francine; Link, Mark S; Schwartz, Joel; Luttmann-Gibson, Heike; Dockery, Douglas W

    2015-01-01

    Outdoor ambient weather has been hypothesized to be responsible for the seasonal distribution of cardiac arrhythmias. Because people spend most of their time indoors, we hypothesized that weather-related arrhythmia risk would be better estimated using an indoor measure or an outdoor measure that correlates well with indoor conditions, such as absolute humidity. The clinical records of 203 patients in eastern Massachusetts, USA, with an implantable cardioverter-defibrillator were abstracted for arrhythmias between 1995 and 2002. We used case-crossover methods to examine the association between weather and ventricular arrhythmia (VA). Among 84 patients who experienced 787 VAs, lower estimated indoor temperature (odds ratio (OR)=1.16, 95% confidence interval (CI) 1.05-1.27 for a 1 °C decrease in the 24-h average) and lower absolute humidity (OR=1.06, 95% CI 1.03-1.08 for a 0.5 g/m(3) decrease in the 96-h average) were associated with increased risk. Lower outdoor temperature increased risk only in warmer months, likely attributable to the poor correlation between outdoor and indoor temperature during cooler months. These results suggest that lower temperature and drier air are associated with increased risk of VA onset among implantable cardioverter-defibrillator patients. PMID:24169878

  19. The influence of motor activity on the development of cardiac arrhythmias during experimental emotional stress

    NASA Technical Reports Server (NTRS)

    Ulyaninskiy, L. S.; Urmancheyeva, T. G.; Stepanyan, Y. P.; Fufacheva, A. A.; Gritsak, A. V.; Kuznetsova, B. A.; Kvitka, A. A.

    1982-01-01

    Experimental emotional stress which can produce various disorders of cardiac rhythm: sinus tachycardia, atrial fibrillation, ventricular, extrasystoles and paroxysmal ventricular tachysystoles was studied. In these conditions the adrenalin content in the blood and myocardium is increased 3 to 4 times. It is found that moderate motor activity leads to a relative decrease of adrenalin in the myocardium and arrest of cardiac arrhythmias.

  20. Brief Report: Emotion Regulation and Respiratory Sinus Arrhythmia in Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Guy, Lisa; Souders, Margaret; Bradstreet, Lauren; DeLussey, Christine; Herrington, John D.

    2014-01-01

    Emotion regulation (ER) may be an important transdiagnostic factor for understanding mental and behavioral health given its association with several psychiatric disorders, including autism spectrum disorder (ASD). However, there is limited research on ER in ASD, particularly using biomarkers such as respiratory sinus arrhythmia (RSA). The aim of…

  1. Use of Whole Exome Sequencing for the Identification of Ito-Based Arrhythmia Mechanism and Therapy

    PubMed Central

    Sturm, Amy C; Kline, Crystal F; Glynn, Patric; Johnson, Benjamin L; Curran, Jerry; Kilic, Ahmet; Higgins, Robert S D; Binkley, Philip F; Janssen, Paul M L; Weiss, Raul; Raman, Subha V; Fowler, Steven J; Priori, Silvia G; Hund, Thomas J; Carnes, Cynthia A; Mohler, Peter J

    2015-01-01

    Background Identified genetic variants are insufficient to explain all cases of inherited arrhythmia. We tested whether the integration of whole exome sequencing with well-established clinical, translational, and basic science platforms could provide rapid and novel insight into human arrhythmia pathophysiology and disease treatment. Methods and Results We report a proband with recurrent ventricular fibrillation, resistant to standard therapeutic interventions. Using whole-exome sequencing, we identified a variant in a previously unidentified exon of the dipeptidyl aminopeptidase-like protein-6 (DPP6) gene. This variant is the first identified coding mutation in DPP6 and augments cardiac repolarizing current (Ito) causing pathological changes in Ito and action potential morphology. We designed a therapeutic regimen incorporating dalfampridine to target Ito. Dalfampridine, approved for multiple sclerosis, normalized the ECG and reduced arrhythmia burden in the proband by >90-fold. This was combined with cilostazol to accelerate the heart rate to minimize the reverse-rate dependence of augmented Ito. Conclusions We describe a novel arrhythmia mechanism and therapeutic approach to ameliorate the disease. Specifically, we identify the first coding variant of DPP6 in human ventricular fibrillation. These findings illustrate the power of genetic approaches for the elucidation and treatment of disease when carefully integrated with clinical and basic/translational research teams. PMID:26015324

  2. Simulation of Cardiac Arrhythmias Using a 2D Heterogeneous Whole Heart Model.

    PubMed

    Balakrishnan, Minimol; Chakravarthy, V Srinivasa; Guhathakurta, Soma

    2015-01-01

    Simulation studies of cardiac arrhythmias at the whole heart level with electrocardiogram (ECG) gives an understanding of how the underlying cell and tissue level changes manifest as rhythm disturbances in the ECG. We present a 2D whole heart model (WHM2D) which can accommodate variations at the cellular level and can generate the ECG waveform. It is shown that, by varying cellular-level parameters like the gap junction conductance (GJC), excitability, action potential duration (APD) and frequency of oscillations of the auto-rhythmic cell in WHM2D a large variety of cardiac arrhythmias can be generated including sinus tachycardia, sinus bradycardia, sinus arrhythmia, sinus pause, junctional rhythm, Wolf Parkinson White syndrome and all types of AV conduction blocks. WHM2D includes key components of the electrical conduction system of the heart like the SA (Sino atrial) node cells, fast conducting intranodal pathways, slow conducting atriovenctricular (AV) node, bundle of His cells, Purkinje network, atrial, and ventricular myocardial cells. SA nodal cells, AV nodal cells, bundle of His cells, and Purkinje cells are represented by the Fitzhugh-Nagumo (FN) model which is a reduced model of the Hodgkin-Huxley neuron model. The atrial and ventricular myocardial cells are modeled by the Aliev-Panfilov (AP) two-variable model proposed for cardiac excitation. WHM2D can prove to be a valuable clinical tool for understanding cardiac arrhythmias. PMID:26733873

  3. Brief history of arrhythmia in the WPW syndrome - the contribution of George Ralph Mines.

    PubMed

    Boukens, Bas J; Janse, Michiel J

    2013-09-01

    George Ralph Mines studied the basic principles of reentry and published his data in The Journal of Physiology in 1913. Exactly 100 years later we discuss his first electrophysiological experiments and how his results lead to the insight that was the basis for the treatment of the clinical arrhythmias seen in Wolff-Parkinson-White syndrome. PMID:23858007

  4. [A case of life-threatening ventricular arrhythmias probably due to psychotropic drugs].

    PubMed

    Kondou, N; Hiasa, Y; Kishi, K; Fujinaga, H; Ohishi, Y; Ohtani, R; Wada, T; Aihara, T

    1993-11-01

    We present a case provoked life-threatening ventricular arrhythmias probably due to psychotropic drugs. The patient was a 55-year-old man who had previously twice operations of aortic valve replacement (AVR). The signs of cardiac failure were recurrently appeared from the end of 1991, and he had received promethazine and sulpiride for his depressive state. From cardiac catheterization, we planned his third AVR. The electrocardiographic (ECG) QTc interval was prolonged to 0.48 seconds on this admission. In March 1992 syncopal attack appeared suddenly, and his monitor ECG revealed frequent polymorphous ventricular tachycardia (VT) and Torsade de Pointes (Tdp). These arrhythmias stopped by emergent cardiac pacing. After discontinuing these psychotropic drugs, no ventricular arrhythmias appeared. Since the patient complained severe insomnia one month before operation, the diminished dose of psychotropic drugs (promethazine and levomepromazine) was readministered. Ten days after the operation, syncopal attack reappeared and his ECG recorded frequent VT and Tdp. During both syncopal attacks his serum potassium and magnesium were within normal limits. Two days later, he died from multi-organ failure. We concluded that life-threatening arrhythmias such as VT and Tdp might develop under the administration of mild psychotropic drugs (promethazine or levomepromazine), therefore, must better take a care of ECG changes in cases of using any psychotropic drugs. PMID:8256055

  5. Online cardiac arrhythmia classification by means of circle maps analysis implemented on an intelligent miniaturized sensor.

    PubMed

    Schiek, Michael; Schlösser, Mario; Schnitzer, Andreas; Ying, Hong

    2008-01-01

    The intermittent occurrence of cardiac arrhythmias like e.g. atrial fibrillation hampers their diagnosis and hence the treatment. Since persons suffering from atrial fibrillation are known to have a remarkable increased risk of stroke the diagnosis of atrial fibrillation is a matter of great importance. Easy and comfortable to use long term ECG recording systems capable of online arrhythmia classification might help to solve this problem. We developed an intelligent, miniaturized, and wireless networking sensor which allows lossless local data recordings up to 4 GB. With its outer dimensions of 20mm per rim and less than 15g of weight including the Lithium-Ion battery our modular designed sensor node is thoroughly capable of up to eight channel recordings with 8 kHz sample rate each and provides sufficient computational power for online digital signal processing. For online arrhythmia classification we will record one ECG channel and 3-axis accelerometer data with 512 Hz each, the later being used for activity classification based artifact identification. We adapted our recently developed circle maps analysis of short term heart rate variation to run on this miniaturized intelligent sensor powered by the Texas Instruments MSP430 microcontroller derivate F1611. With this configuration we started to evaluate the cardiac arrhythmia classification in long term ECG recordings. PMID:19162988

  6. Role of respiratory sleep disorders in the pathogenesis of nocturnal angina and arrhythmias.

    PubMed Central

    Liston, R.; Deegan, P. C.; McCreery, C.; McNicholas, W. T.

    1994-01-01

    This report documents how respiratory sleep disorders can adversely effect ischaemic heart disease. Three male patients (aged 60-67 years) with proven ischaemic heart disease are described. They illustrate a spectrum of nocturnal cardiac dysfunction, two with nocturnal angina and one with nocturnal arrhythmias. Full sleep studies were performed in a dedicated sleep laboratory on all patients, and one patient had 48 hours of continuous Holter monitoring. Two patients were found to have obstructive sleep apnoea with apnoea/hypopnoea indices of 57 and 36 per hour, respectively, the former with nocturnal arrhythmias and the latter with nocturnal angina. In both cases, nasal continuous positive airways pressure successfully treated the sleep apnoea, with an associated improvement in nocturnal arrhythmias and angina. The third patient who presented with nocturnal angina, did not demonstrate obstructive sleep apnoea (apnoea/hypopnoea index = 7.2) but had significant oxygen desaturation during rapid eye movement (REM) sleep. This patient responded to a combination of nocturnal oxygen and protriptyline, an agent known to suppress REM sleep, and had no further nocturnal angina. All patients were considered to be an optimum cardiac medication and successful symptom resolution only occurred with the addition of specific therapy aimed at their sleep-related respiratory problem. We conclude that all patients with nocturnal angina or arrhythmias should have respiratory sleep abnormalities considered in their assessment. PMID:8183772

  7. Arrhythmia-induced cardiomyopathies: the riddle of the chicken and the egg still unanswered?

    PubMed

    Simantirakis, Emmanuel N; Koutalas, Emmanuel P; Vardas, Panos E

    2012-04-01

    The hypothesis testing of inappropriate fast, irregular, or asynchronous myocardial contraction provoking cardiomyopathy has been the primary focus of numerous research efforts, especially during the last few decades. Rapid ventricular rates resulting from supraventricular arrhythmias and atrial fibrillation (AF), irregularity of heart rhythm-basic element of AF-and asynchrony, as a consequence of right ventricular pacing, bundle branch block, or frequent premature ventricular complexes, have been established as primary causes of arrhythmia-induced cardiomyopathy. The main pathophysiological pathways involved have been clarified, including neurohumoral activation, energy stores depletion, and abnormalities in stress and strain. Unfortunately, from a clinical point of view, patients usually seek medical advice only when symptoms develop, while the causative arrhythmia may be present for months or years, resulting in myocardial remodelling, diastolic, and systolic dysfunction. In some cases, making a definite diagnosis may become a strenuous exercise for the treating physician, as the arrhythmia may not be present and, additionally, therapy must be applied for the diagnosis to be confirmed retrospectively. The diagnostic process is also hardened due to the fact that strict diagnosing criteria are still a matter of discrepancy. Therapy options include pharmaceutical agents trials, catheter-based therapies and, in the context of chronic ventricular pacing, resynchronization. For the majority of patients, partial or complete recovery is expected, although they have to be followed up thoroughly due to the risk of recurrence. Large, randomized controlled trials are more than necessary to optimize patients' stratification and therapeutic strategy choices. PMID:22084300

  8. Behavioral Inhibition, Heart Period, and Respiratory Sinus Arrhythmia: An Attachment Perspective.

    ERIC Educational Resources Information Center

    Stevenson-Hinde, Joan; Marshall, Peter J.

    1999-01-01

    Examined interrelations among behavioral inhibition (BI), cardiac activity, and attachment status in 4.5-year olds. Found that only Secure children showed predicted relationship between low BI and high heart period (HP) or respiratory sinus arrhythmia. Increases in HP from assessment during separation from mother to assessment three minutes after…

  9. Interrogation of Patient Smartphone Activity Tracker to Assist Arrhythmia Management.

    PubMed

    Rudner, Joshua; McDougall, Carol; Sailam, Vivek; Smith, Monika; Sacchetti, Alfred

    2016-09-01

    A 42-year-old man presented to the emergency department (ED) with newly diagnosed atrial fibrillation of unknown duration. Interrogation of the patient's wrist-worn activity tracker and smartphone application identified the onset of the arrhythmia as within the previous 3 hours, permitting electrocardioversion and discharge of the patient from the ED. PMID:27045694

  10. Arrhythmias and Other Electrophysiology Issues in Cancer Patients Receiving Chemotherapy or Radiation.

    PubMed

    Viganego, Federico; Singh, Robin; Fradley, Michael G

    2016-06-01

    Enhanced understanding of cancer biology has significantly increased treatment options and dramatically improved outcomes for patients with malignancies. Despite these advances, many therapies have cardiovascular toxicities which can affect morbidity and mortality independent of the oncologic prognosis. Arrhythmias and other electrophysiology issues are increasingly identified as common complications of cancer therapy. Atrial fibrillation and other supraventricular arrhythmias are frequently observed in cancer patients receiving chemotherapy, often due to their effects on intracellular signaling pathways. Similarly, many oncologic pharmaceuticals can lead to QT prolongation and possible ventricular arrhythmias including torsades do pointes. Management of these arrhythmias can be challenging as typical treatment strategies may not be feasible in cancer patients. Finally, a proportion of individuals with cancer will present with an implantable cardiac device (pacemaker or defibrillator) which poses unique challenges should radiation be necessary in the region of the device. Given the frequency of electrophysiology complications in cancer patients, it is essential for cardio-oncologists to possess knowledge of these issues in order to provide optimal care. PMID:27108362

  11. Weather and triggering of ventricular arrhythmias in patients with implantable cardioverter-defibrillators

    PubMed Central

    Nguyen, Jennifer L.; Laden, Francine; Link, Mark S.; Schwartz, Joel; Luttmann-Gibson, Heike; Dockery, Douglas W.

    2015-01-01

    Outdoor ambient weather has been hypothesized to be responsible for the seasonal distribution of cardiac arrhythmias. Because people spend most of their time indoors, we hypothesized that weather-related arrhythmia risk would be better estimated using an indoor measure or an outdoor measure that correlates well with indoor conditions, such as absolute humidity. The clinical records of 203 patients in eastern Massachusetts, USA, with an implantable cardioverter-defibrillator were abstracted for arrhythmias between 1995 and 2002. We used case-crossover methods to examine the association between weather and ventricular arrhythmia (VA). Among 84 patients who experienced 787 VAs, lower estimated indoor temperature (odds ratio (OR) = 1.16, 95% confidence interval (CI) 1.05–1.27 for a 1 °C decrease in the 24-h average) and lower absolute humidity (OR = 1.06, 95% CI 1.03–1.08 for a 0.5 g/m3 decrease in the 96-h average) were associated with increased risk. Lower outdoor temperature increased risk only in warmer months, likely attributable to the poor correlation between outdoor and indoor temperature during cooler months. These results suggest that lower temperature and drier air are associated with increased risk of VA onset among implantable cardioverter-defibrillator patients. PMID:24169878

  12. Brief Report: Social Skills, Internalizing and Externalizing Symptoms, and Respiratory Sinus Arrhythmia in Autism

    ERIC Educational Resources Information Center

    Neuhaus, Emily; Bernier, Raphael; Beauchaine, Theodore P.

    2014-01-01

    Theoretical and empirical models describe respiratory sinus arrhythmia (RSA) as a peripheral biomarker of emotion regulation and social competence. Recent findings also link RSA to individual differences in social functioning within autism spectrum disorder (ASD). However, associations between RSA and symptoms of internalizing/externalizing…

  13. Congenital Deafness with Cardiac Arrhythmias: The Jervell and Lange-Nielsen Syndrome.

    ERIC Educational Resources Information Center

    Wahl, Richard A.; Macdonald, Dick, II

    1980-01-01

    The Jervell and Lange-Nielsen syndrome, affecting 0.3 percent of congenitally deaf persons, consists of severe cardiac arrhythmias and sensorineural hearing loss. The authors recommend that every congenitally deaf child with suspicious symptoms receive an electrocardiogram and that professionals who work with deaf children not only inform…

  14. Reducing false arrhythmia alarms in the ICU using multimodal signals and robust QRS detection.

    PubMed

    Sadr, Nadi; Huvanandana, Jacqueline; Nguyen, Doan Trang; Kalra, Chandan; McEwan, Alistair; de Chazal, Philip

    2016-08-01

    This study developed algorithms to decrease the arrhythmia false alarms in the ICU by processing multimodal signals of photoplethysmography (PPG), arterial blood pressure (ABP), and two ECG signals. The goal was to detect the five critical arrhythmias comprising asystole (ASY), extreme bradycardia (EBR), extreme tachycardia (ETC), ventricular tachycardia (VTA), and ventricular flutter or fibrillation (VFB). The different characteristics of the arrhythmias suggested the application of individual signal processing for each alarm and the combination of the algorithms to enhance false alarm detection. Thus, different features and signal processing techniques were used for each arrhythmia type. The ECG signals were first processed to reduce the signal interference. Then, a Hilbert-transform based QRS detector algorithm was utilized to identify the QRS complexes, which were then processed to determine the instantaneous heart rate. The pulsatile signals (PPG and ABP) were processed to discover the pulse onset of beats which were then employed to measure the heart rate. The signal quality index (SQI) of the signals was implemented to verify the integrity of the heart rate information. The overall score obtained by our algorithms in the 2015 Computing in Cardiology Challenge was a score of 74.03% for retrospective and 69.92% for real-time analysis. PMID:27455121

  15. [Correlation between QT interval, ventricular arrhythmias and left ventricular function in chronic alcoholics].

    PubMed

    Pomini, G; Gribaldo, R; Bellavere, F; Lupia, M; Sale, F; Rugna, A; Costa, L; Molfese, G

    1986-04-01

    Prolonged QT interval and arrhythmias have been reported to occur in chronic alcoholics. To investigate the role of chronic alcohol consumption in the onset of arrhythmias and the development of the preclinical left ventricular dysfunction, in a group of 12 asymptomatic chronic alcoholics with no clinical evidence of heart disease, with histologically proven hepatic damage, after a week of abstinence from alcohol, the following investigations were performed: measurements of the corrected QT interval (QTc), 24-hours Holter monitoring, systolic time intervals, M-mode echocardiograms. The results were compared to those of 10 normal subjects. Our data suggested no difference in QTc interval between chronic alcoholics and normal persons. The distribution of arrhythmias was not statistically different in the two groups, particularly frequent and complicated arrhythmias occurred in only one subject in each group. Preejection period corrected for heart rate (PEPI) was significantly longer in alcoholics (132 +/- 16 vs 119 +/- 11, p less than 0.05). All echocardiographic parameters examined were not significantly different in the two groups. On the basis of our results, our impression is that the arrhythmogenic role of alcohol, not under acute ingestion, is relatively unimportant and further studies are needed to become a definitive conclusion about subclinical alcoholic cardiomyopathy. PMID:3743931

  16. New Analysis of the ν_3 Band of HDCO (monodeuterated Formaldehyde) in the 5.8 μm Region

    NASA Astrophysics Data System (ADS)

    Gomez, L.; Perrin, A.; Mellau, G. C.

    2009-06-01

    Using high-resolution Fourier transform spectra of mono deuterated formaldehyde (HDCO) recorded in the 5.8 μm spectral range at Giessen (Germany), we carried out an extensive analysis of the strong ν_3 fundamental band (carbonyl stretching mode) at 1724.2676 cm^{-1}, starting from results of a previous analysis. For this hybrid band (with both A- and B-type transitions) the analysis was pursued up to high rotational quantum numbers. In this way, it was possible to evidence resonances which perturb the ν_3 lines which are due to the existence of the 2ν_5 (at 2059 cm^{-1}) and ν_5+ν_6 (at 2087 cm^{-1}) dark bands. In addition a local resonance is perturbing the 3^1 levels which is due to a crossing with the 4^1 energy levels. However the 4^1 state is also involved in strong vibration-rotation interactions coupling the {5^1,6^1,4^1} system of resonating states of HDCO J. Mol. Spectrosc. 216, 214 (2002)}. Therefore the final energy levels calculation which was performed for the {5^1,6^1,4^1,3^1,5^2,5^16^1} resonating states accounts for the observed A- type, B- type C-type Coriolis (and/or) Fermi resonances. In this way it was possible to reproduce the observed line positions, within their experimental uncertainties. Finally using a ν_3 band intensity available in the literature we generated, for the first time, a list of line parameters (positions and intensities) for the 5.8 μm band of HDCO. [1] Johns JWC, McKellar ARW., J Mol Spectrosc 1977; 64: 327-339 [2] ν_4, ν_5 and ν_6 correspond to the CHD bending (at 1396 cm^{-1}), the CHD rocking (at 1028 cm^{-1}) and the CHD out of plane (at 1059 cm^{-1}) modes, respectively}. [3] A. Perrin, J. M. Flaud, L. Margulès, J. Demaison, H. Mäder and S. Wörmke, J. Mol. Spectrosc. 216, 214 (2002) [4] Gratien, Nilsson, Doussin, Johnson, Nielsen, Stenstrom and Picquet-Varrault, J. Phys. Chem. 111, 11506 (2007)

  17. Macrolide antibiotics and the risk of ventricular arrhythmia in older adults

    PubMed Central

    Trac, Mai H.; McArthur, Eric; Jandoc, Racquel; Dixon, Stephanie N.; Nash, Danielle M.; Hackam, Daniel G.; Garg, Amit X.

    2016-01-01

    Background: Many respiratory tract infections are treated with macrolide antibiotics. Regulatory agencies warn that these antibiotics increase the risk of ventricular arrhythmia. We examined the 30-day risk of ventricular arrhythmia and all-cause mortality associated with macrolide antibiotics relative to nonmacrolide antibiotics. Methods: We conducted a population-based retrospective cohort study involving older adults (age > 65 yr) with a new prescription for an oral macrolide antibiotic (azithromycin, clarithromycin or erythromycin) in Ontario from 2002 to 2013. Our primary outcome was a hospital encounter with ventricular arrhythmia within 30 days after a new prescription. Our secondary outcome was 30-day all-cause mortality. We matched patients 1:1 using propensity scores to patients prescribed nonmacrolide antibiotics (amoxicillin, cefuroxime or levofloxacin). We used conditional logistic regression to measure the association between macrolide exposure and outcomes, and repeated the analysis in 4 subgroups defined by the presence or absence of chronic kidney disease, congestive heart failure, coronary artery disease and concurrent use of a drug known to prolong the QT interval. Results: Compared with nonmacrolide antibiotics, macrolide antibiotics were not associated with a higher risk of ventricular arrhythmia (0.03% v. 0.03%; relative risk [RR] 1.06, 95% confidence interval [CI] 0.83–1.36) and were associated with a lower risk of all-cause mortality (0.62% v. 0.76%; RR 0.82, 95% CI 0.78–0.86). These associations were similar in all subgroups. Interpretation: Among older adults, macrolide antibiotics were not associated with a higher 30-day risk of ventricular arrhythmia than nonmacrolide antibiotics. These findings suggest that current warnings from the US Food and Drug Administration may be overstated. PMID:26903359

  18. Medical Decision Support System for Diagnosis of Heart Arrhythmia using DWT and Random Forests Classifier.

    PubMed

    Alickovic, Emina; Subasi, Abdulhamit

    2016-04-01

    In this study, Random Forests (RF) classifier is proposed for ECG heartbeat signal classification in diagnosis of heart arrhythmia. Discrete wavelet transform (DWT) is used to decompose ECG signals into different successive frequency bands. A set of different statistical features were extracted from the obtained frequency bands to denote the distribution of wavelet coefficients. This study shows that RF classifier achieves superior performances compared to other decision tree methods using 10-fold cross-validation for the ECG datasets and the obtained results suggest that further significant improvements in terms of classification accuracy can be accomplished by the proposed classification system. Accurate ECG signal classification is the major requirement for detection of all arrhythmia types. Performances of the proposed system have been evaluated on two different databases, namely MIT-BIH database and St. -Petersburg Institute of Cardiological Technics 12-lead Arrhythmia Database. For MIT-BIH database, RF classifier yielded an overall accuracy 99.33 % against 98.44 and 98.67 % for the C4.5 and CART classifiers, respectively. For St. -Petersburg Institute of Cardiological Technics 12-lead Arrhythmia Database, RF classifier yielded an overall accuracy 99.95 % against 99.80 % for both C4.5 and CART classifiers, respectively. The combined model with multiscale principal component analysis (MSPCA) de-noising, discrete wavelet transform (DWT) and RF classifier also achieves better performance with the area under the receiver operating characteristic (ROC) curve (AUC) and F-measure equal to 0.999 and 0.993 for MIT-BIH database and 1 and 0.999 for and St. -Petersburg Institute of Cardiological Technics 12-lead Arrhythmia Database, respectively. Obtained results demonstrate that the proposed system has capacity for reliable classification of ECG signals, and to assist the clinicians for making an accurate diagnosis of cardiovascular disorders (CVDs). PMID:26922592

  19. [Identification of patients at risk of malignant arrhythmia in the 1st year after myocardial infarction].

    PubMed

    Araya-Gómez, V; González-Hermosillo, J A; Casanova Garcés, J M; Colín, L; Kershenovich, S; Iturralde, P

    1994-01-01

    Two hundred twenty two consecutive patients with acute myocardial infarction were followed for one year. We evaluated the usefulness of late potentials, the spectral analysis, heart rate variability, infarct-related coronary artery, ejection fraction, arrhythmias during Holter monitoring and other clinical variables as risk markers for developing of ventricular arrhythmias and/or sudden death. Twenty four patients (10.8%) had late arrhythmic events: sudden death in 7, sustained ventricular tachycardia in 15 and unexplained syncope in 2. Late potentials had high sensitivity (94%) and negative predictive value (99%), followed by an occluded related-infarct coronary artery (75% sensitivity and 96% negative predictive value). Complex ventricular arrhythmias during Holter monitoring was the test with the highest specificity (92%). A combination of late potentials plus an occluded infarct-related coronary artery or late potentials plus ejection fraction showed 100% sensitivity with 100% negative predictive value. Of the 16 studied variables, 5 had independent and significative value as a predictor of arrhythmic events, these are, according to the relative risk: late potentials (20.2), ejection fraction less than 40% (12.1), complex arrhythmias during Holter monitoring (7.5), the presence of an occluded infarct-related coronary artery (6.4) and anterior myocardial infarction localization (4.5). We consider, that with a combination of simple methods of assessment, we can select a subgroup of survivors of an acute myocardial infarction at high risk of developing ventricular arrhythmias and sudden death, which also identifies patients with low risk for these complications. PMID:8074586

  20. Reversible redox modifications of ryanodine receptor ameliorate ventricular arrhythmias in the ischemic-reperfused heart.

    PubMed

    Becerra, Romina; Román, Bárbara; Di Carlo, Mariano N; Mariangelo, Juan Ignacio; Salas, Margarita; Sanchez, Gina; Donoso, Paulina; Schinella, Guillermo R; Vittone, Leticia; Wehrens, Xander H; Mundiña-Weilenmann, Cecilia; Said, Matilde

    2016-09-01

    Previous results from our laboratory showed that phosphorylation of ryanodine receptor 2 (RyR2) by Ca(2+) calmodulin-dependent kinase II (CaMKII) was a critical but not the unique event responsible for the production of reperfusion-induced arrhythmogenesis, suggesting the existence of other mechanisms cooperating in an additive way to produce these rhythm alterations. Oxidative stress is a prominent feature of ischemia/reperfusion injury. Both CaMKII and RyR2 are proteins susceptible to alteration by redox modifications. This study was designed to elucidate whether CaMKII and RyR2 redox changes occur during reperfusion and whether these changes are involved in the genesis of arrhythmias. Langendorff-perfused hearts from rats or transgenic mice with genetic ablation of CaMKII phosphorylation site on RyR2 (S2814A) were subjected to ischemia-reperfusion in the presence or absence of a free radical scavenger (mercaptopropionylglycine, MPG) or inhibitors of NADPH oxidase and nitric oxide synthase. Left ventricular contractile parameters and monophasic action potentials were recorded. Oxidation and phosphorylation of CaMKII and RyR2 were assessed. Increased oxidation of CaMKII during reperfusion had no consequences on the level of RyR2 phosphorylation. Avoiding the reperfusion-induced thiol oxidation of RyR2 with MPG produced a reduction in the number of arrhythmias and did not modify the contractile recovery. Conversely, selective prevention of S-nitrosylation and S-glutathionylation of RyR2 was associated with higher numbers of arrhythmias and impaired contractility. In S2814A mice, treatment with MPG further reduced the incidence of arrhythmias. Taken together, the results suggest that redox modification of RyR2 synergistically with CaMKII phosphorylation modulates reperfusion arrhythmias. PMID:27422983