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Sample records for bundle branch block

  1. Bundle Branch Block

    Science.gov (United States)

    ... 2015. Bundle branch block Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  2. Right bundle branch block

    DEFF Research Database (Denmark)

    Bussink, Barbara E; Holst, Anders Gaarsdal; Jespersen, Lasse

    2013-01-01

    AimsTo determine the prevalence, predictors of newly acquired, and the prognostic value of right bundle branch block (RBBB) and incomplete RBBB (IRBBB) on a resting 12-lead electrocardiogram in men and women from the general population.Methods and resultsWe followed 18 441 participants included.......5%/2.3% in women, P Right bundle branch block was associated with significantly...... increased all-cause and cardiovascular mortality in both genders with age-adjusted hazard ratios (HR) of 1.31 [95% confidence interval (CI), 1.11-1.54] and 1.87 (95% CI, 1.48-2.36) in the gender pooled analysis with little attenuation after multiple adjustment. Right bundle branch block was associated...

  3. Left bundle-branch block

    DEFF Research Database (Denmark)

    Risum, Niels; Strauss, David; Sogaard, Peter

    2013-01-01

    The relationship between myocardial electrical activation by electrocardiogram (ECG) and mechanical contraction by echocardiography in left bundle-branch block (LBBB) has never been clearly demonstrated. New strict criteria for LBBB based on a fundamental understanding of physiology have recently...

  4. Axis deviation without left bundle branch block.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Mancuso, Antonia

    2010-04-15

    It has been rarely reported changing axis deviation in the presence of left bundle branch block also during atrial fibrillation and with acute myocardial infarction too. It has also been rarely reported changing axis deviation with changing bundle branch block with onset of atrial fibrillation during acute myocardial infarction. We present a case of axis deviation without left bundle branch block and without atrial fibrillation and acute myocardial infarction in a 65-year-old Italian man. To our knowledge, this is the first report of axis deviation without left bundle branch block and without atrial fibrillation and acute myocardial infarction. Copyright 2008 Elsevier Ireland Ltd. All rights reserved.

  5. Masquerading bundle branch block: a variety of right bundle branch block with left anterior fascicular block.

    Science.gov (United States)

    Elizari, Marcelo V; Baranchuk, Adrian; Chiale, Pablo A

    2013-01-01

    The so-called 'masquerading' type of right bundle branch block is caused by the simultaneous presence of a high-degree left anterior fascicular block often accompanied with severe left ventricular enlargement and/or fibrotic block in the anterolateral wall of the left ventricle. These conditions tend to reorient the terminal electrical forces of the QRS complex towards the left and upwards, in such a way that the characteristic slurred S wave in lead I becomes smaller or even disappears. In many cases of standard masquerading right bundle branch block, a small Q wave in lead I is present due to the initial forces of the left anterior fascicular block, which are oriented rightwards and inferiorly. However, in some cases, the Q wave in lead I also vanishes, and the mimicking of a left bundle branch block becomes perfect in standard leads. This is commonly associated with an inferior myocardial infarction or severe inferior fibrosis in cardiomyopathies. The typical QRS changes of right bundle branch block may eventually be concealed even in the right precordial leads; under such circumstances, the ECG diagnosis may be mistaken and the right bundle branch block totally missed. The masquerading right bundle branch block carries a poor prognosis, since it always implies the presence of a severe underlying heart disease.

  6. A case of 'Masquerading' bundle branch block: a forgotten concept.

    Science.gov (United States)

    Choudhary, Dinesh; Namboodiri, Narayanan; Tharakan, Jaganmohan A

    2014-01-01

    'Masquerading' bundle branch block (right bundle branch block in the precordial leads with left bundle branch block in frontal leads and left axis deviation) is seen most commonly with coronary artery disease and hypertension. No definite explanation is available so far for these changes. We are presenting a case of rare congenital intranuclear inclusion myopathy with congestive heart failure and 'Masquerading' bundle branch block in ECG. Copyright © 2013 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  7. Baseline left bundle branch block with right bundle branch escape complexes in a patient with coronary artery disease, presents like an alternating bundle branch block: a case report

    Science.gov (United States)

    Bhimaraj, Arvind; Abusin, Salaheldin; Margeta, Bosko

    2008-01-01

    Alternating bundle branch block (ABBB) is a less commonly encountered phenomenon with the advent of re-perfusion therapy for acute myocardial infarction. ECGs simulating the appearance of an ABBB need to be carefully analysed. We present an ECG showing a baseline Left Bundle Branch Block(LBBB) progressing to a high grade AV block with escape complexes having a Right Bundle Branch Block (RBBB) morphology. Such an ECG can be mistaken for an ABBB if not analysed carefully. PMID:19116014

  8. [Bundle-branch block depending on the heart rate].

    Science.gov (United States)

    Apostolov, L

    1975-01-01

    Five patients are reported, admitted to the hospital, with diseases predominantly of the cardio-vascular system. During the electrocardiographic examinations bundle branch block was established, depending on heart rate. It fluctuated within the physiological limits from 50 to 90/min. In three of the patients, the bundle branch block appeared with the quickening of the heart rate (tachycardia-depending bundle branch block) and in two of the patients--the bundle branch block appeared during the slowing down of the heart action and disappeared with its quickening (bradicardia-depending bundle branch block). A brief literature review is presented and attention is paid to the possible diagnostic errors and the treatment mode of those patients with cardiac tonic and antiarrhythmic medicaments.

  9. Transient Left Bundle Branch Block due to Severe Hyperkalemia.

    Science.gov (United States)

    Kumar, Kishore; Biyyam, Madhavi; Singh, Amandeep; Bajantri, Bharat; Tariq, Hassan; Nayudu, Suresh Kumar; Chilimuri, Sridhar

    2017-04-01

    Hyperkalemia is a potentially life-threatening electrolyte imbalance that can lead to sudden death from cardiac arrhythmias and asystole. We present a case of transient left bundle branch block pattern on an electrocardiogram (ECG) secondary to hyperkalemia in a patient with history of end-stage renal disease. A 52-year-old man presented to the emergency room (ER) with chief complaints of weakness and lethargy after missing his regularly scheduled session of hemodialysis. A 12-lead ECG in the ER showed sinus tachycardia at 118 beats/min, wide QRS complexes, peaked T waves and left bundle branch block-like pattern. The initial basic metabolic panel revealed a serum potassium level of 8.8 mEq/L. Subsequently, the patient underwent emergent hemodialysis. Serum chemistry after hemodialysis showed improvement in serum potassium to 4.3 mEq/L. Repeat ECG performed after correcting potassium showed dissolution of left bundle branch block finding.

  10. MYOCARDIAL DEFORMATION AND COMPLETE LEFT BUNDLE BRANCH BLOCK

    Directory of Open Access Journals (Sweden)

    E. N. Pavlyukova

    2015-12-01

    Full Text Available Tissue Doppler imaging is evolving as a useful echocardiographic tool for quantitative assessment of left ventricular systolic and diastolic function. Over the last 10 years, myocardial deformation imaging has become possible initially with tissue Doppler , and more recently with myocardial speckle-tracking using 2D echocardiography. Unlike simple tissue velocity measurements, deformation measurements are specific for the region of interest. Strain rate or strain measurements have been used as sensitive indicators for subclinical diseases, and it is the most widely used tool to assess mechanical dyssynchrony. Left bundle branch block is a frequent, etiologically heterogeneous, clinically hostile and diagnostically challenging entity. About 2% of patients underwent cardiac stress testing show stable or intermittent left bundle branch block. Presence of left bundle branch block is associated with a lower and slower diastolic coronary flow velocity especially during hyperemia. Stress echocardiography is the best option for the diagnosis of ischemic heart disease, albeit specificity and sensitivity reduce in patients with left bundle branch block in the territory of left anterior descending artery in presence of initial septum dyskinesia.

  11. Left Bundle Branch Block and Complete Heart Block Complicating Inferior Myocardial Infarction.

    Science.gov (United States)

    Gruber, Jillian S; Stair, Brad; Aktas, Mehmet; Bravo-Jaimes, Katia

    2017-01-01

    Left bundle branch block following inferior myocardial infarction remains uncommon and scarcely reported in the literature. We describe a rare presentation of a 58-year-old male patient who developed left bundle branch block and third degree atrioventricular block after inferior myocardial infarction requiring permanent pacemaker placement. Pathophysiology, impact on mortality, and management options are discussed. © 2016 Wiley Periodicals, Inc.

  12. A quantitative histopathological study of right bundle branch block complicating acute anteroseptal myocardial infarction.

    OpenAIRE

    Okabe, M; Fukuda, K; Nakashima, Y; Hiroki, T; Arakawa, K; Kikuchi, M

    1991-01-01

    The aim of the present study was to evaluate whether necrosis of the right bundle branch is responsible for development of right bundle branch block in acute myocardial infarction. Twenty patients with acute anteroseptal myocardial infarction were studied--10 with right bundle branch block (group A) and 10 without (group B)--to evaluate by serial sectioning the pathological extent of myocardial infarction surrounding the right bundle branch and also that of right bundle branch necrosis. Myoca...

  13. Is It Complete Left Bundle Branch Block? Just Ablate the Right Bundle.

    Science.gov (United States)

    Ali, Hussam; Lupo, Pierpaolo; Foresti, Sara; De Ambroggi, Guido; Epicoco, Gianluca; Fundaliotis, Angelica; Cappato, Riccardo

    2017-03-01

    Complete left bundle branch block (LBBB) is established according to standard electrocardiographic criteria. However, functional LBBB may be rate-dependent or can perpetuate during tachycardia due to repetitive concealed retrograde penetration of impulses through the contralateral bundle "linking phenomenon." In this brief article, we present two patients with basal complete LBBB in whom ablating the right bundle unmasked the actual antegrade conduction capabilities of the left bundle. These cases highlight intriguing overlap between electrophysiological concepts of complete block, linking, extremely slow, and concealed conduction. © 2016 Wiley Periodicals, Inc.

  14. A case of ‘Masquerading’ bundle branch block: A forgotten concept

    OpenAIRE

    Dinesh Choudhary; Narayanan Namboodiri; Jaganmohan A. Tharakan

    2014-01-01

    ‘Masquerading’ bundle branch block (right bundle branch block in the precordial leads with left bundle branch block in frontal leads and left axis deviation) is seen most commonly with coronary artery disease and hypertension. No definite explanation is available so far for these changes. We are presenting a case of rare congenital intranuclear inclusion myopathy with congestive heart failure and ‘Masquerading’ bundle branch block in ECG.

  15. Structural Causes of Right Bundle Branch Block?Time for a Closer Look?

    OpenAIRE

    Ker, James

    2010-01-01

    Right bundle branch block is an electrocardiographic phenomenon with specific criteria. Currently, two specific forms of right bundle branch block are acknowledged, a proximal and a distal variant. A vast array of pathologies can cause proximal, distal or even combined forms of right bundle branch block. In this study it is suggested that a third type of right bundle branch block exist: one caused by a subaortic muscular tendon in the left ventricle, leading to an increased velocity of conduc...

  16. Physiological mechanisms of QRS narrowing in bundle branch block patients undergoing permanent His bundle pacing.

    Science.gov (United States)

    Teng, Alexandra E; Massoud, Louis; Ajijola, Olujimi A

    2016-01-01

    His bundle pacing is increasingly used to avoid chronic right ventricular pacing, and electrically resynchronize ventricular activation by narrowing or normalizing the QRS interval in left and right bundle branch block. The mechanisms by which this occurs remain poorly understood. In this review, the proposed mechanisms and evidence supporting them are discussed. Also discussed are aspects of mechanisms that are not completely supported by the evidence. We also review the differences and physiological bases for direct vs. indirect His bundle capture, and the physiological mechanisms for QRS narrowing vs. normalization following His bundle pacing. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Isolated Left Bundle Branch Block in a Toddler

    Directory of Open Access Journals (Sweden)

    Hitesh Agrawal

    2014-01-01

    Full Text Available Left bundle branch block (LBBB usually occurs as a postoperative complication from surgical correction of congenital heart disease and can be associated with hypertensive heart disease, coronary artery disease, myocarditis, and aortic valvular disease. Although isolated LBBB is a conduction abnormality found in some healthy adults, it has not been reported in pediatric population. We report a 2-year-old, healthy African American female who was incidentally discovered to have isolated LBBB that has persisted in a follow-up of 3 years.

  18. Isolated Left Bundle Branch Block in a Toddler

    Science.gov (United States)

    Zimmerman, Frank; Naheed, Zahra

    2014-01-01

    Left bundle branch block (LBBB) usually occurs as a postoperative complication from surgical correction of congenital heart disease and can be associated with hypertensive heart disease, coronary artery disease, myocarditis, and aortic valvular disease. Although isolated LBBB is a conduction abnormality found in some healthy adults, it has not been reported in pediatric population. We report a 2-year-old, healthy African American female who was incidentally discovered to have isolated LBBB that has persisted in a follow-up of 3 years. PMID:24963416

  19. Masquerading bundle branch block as a presenting manifestation of complete atrioventricular block that caused syncope.

    Science.gov (United States)

    Jiao, Zhenyu; Tian, Ying; Yang, Xinchun; Liu, Xingpeng

    2017-10-01

    A 59-year-old male patient was admitted with the main complaints of stuffiness and shortness of breath. An ECG from precordial leads on admission showed masquerading bundle branch block. Syncope frequently occurred after admission. During syncope episodes, ECG telemetry showed that the syncope was caused by intermittent complete atrioventricular block, with the longest RR interval lasting for 4.36 s. At the gap of syncope, ECG showed complete right bundle branch block accompanied by alternation of left anterior fascicular block and left posterior fascicular block. The patient was implanted with a dual-chamber permanent pacemaker. Follow-up of 9 months showed no reoccurrence of syncope.

  20. Recurrent extensive anterior myocardial infarction with left and right bundle branch block.

    Science.gov (United States)

    Jiang, Hexi; Chang, Qinghua; Zhang, Yingjie; Liu, Renguang

    2017-10-15

    The diagnosis of myocardial infarction with left bundle branch block is difficult. We report a case of 56-year-old man with old extensive anterior myocardial infarction and left bundle branch block (masked each other). The recurrent myocardial infarction indicated right bundle branch block and first-degree atrioventricular block, making a clear diagnosis of complicated and interesting ECG. © 2017 Wiley Periodicals, Inc.

  1. Harder Roads to Trek? Paradoxical Slowing of an Atrioventricular Reentrant Tachycardia With Contralateral Bundle Branch Block.

    Science.gov (United States)

    Divakara Menon, Syamkumar M; Ayati, Maryam; Healey, Jeff S

    2017-04-01

    Slowing of the tachycardia with increase in cycle length and increase in VA time with ipsilateral bundle branch block is a characteristic feature of accessory pathway mediated AVRT. Contralateral bundle branch block has no effect on the tachycardia as it is not a part of the tachycardia circuit. We present an interesting phenomenon in which contralateral bundle branch block resulted in tachycardia slowing in a case of WPW syndrome. © 2016 Wiley Periodicals, Inc.

  2. Left bundle-branch block with right axis deviation--a unique aberrancy during supraventricular tachycardia.

    Science.gov (United States)

    Lokhandwala, Yash; Panicker, Gopi Krishna; Shah, Mandar; Wellens, Hein J J

    2009-01-01

    A tachycardia with left bundle-branch block morphology and right axis deviation points to the diagnosis of ventricular tachycardia. Conversely, any supraventricular tachycardia with left bundle-branch block is typically associated with a normal or leftward QRS axis. We present the case of a 34-year-old man showing atrioventricular nodal reentrant tachycardia with left bundle-branch block/right axis deviation as an exception to this rule.

  3. [Intermittent bundle branch block: a clinical model for the study of electrophysiological phenomena].

    Science.gov (United States)

    Costantini, Marcello

    2014-01-01

    Disorders of intraventricular conduction (bundle branch block and hemiblock) are usually stable and remain unchanged irrespective of heart rate. Not infrequently, however, their appearance is related to the duration of the cardiac cycle, so that they appear and disappear with changes in heart rate. This may not even represent a pathological phenomenon, since sudden and consistent changes in cardiac cycle can result, even physiologically, in aberrant conduction. However, when a bundle branch block appears intermittently for simple and progressive increments, or even deceleration, of the sinus rate, this is related to a true bundle branch pathology, i.e. tachycardia-dependent (or phase 3) block or bradycardia-dependent (or phase 4) block, respectively. Phase 3 block is believed to express a pathological increase in the duration of the recovery period of the bundle branch. Phase 4 block was best explained on the basis of enhanced phase 4 depolarization of the bundle branch system, with inability of excitation if the cardiac cycle is particularly prolonged. The two types of block, phase 3 and phase 4, often coexist. An intraventricular conduction disturbance that appears during increasing heart rate for a phase 3 block is maintained, if frequency slows down, even for cycles greater than those that brought about its appearance. This is due to retrograde activation of the bundle branch blocked in the antegrade direction, with delay of its action potential inscription. Sometimes, in the presence of phase 3 bundle branch block, very early atrial ectopic beats are paradoxically conducted in the normal way (supernormal conduction). Perhaps, this phenomenon is related to a possible "climb over" of the injured zone of the bundle branch by the blocked impulses that arise beyond the injured area as subliminal impulses, exciting the healthy tissues if catches them during their phase of supernormal excitability. In the presence of intermittent bundle branch block, it is not

  4. Rare Manifestation of Digoxin Toxicity: Right Bundle Branch Block

    Science.gov (United States)

    Gill, Dalvir; Zaidi, Samana

    2016-01-01

    A 76-year-old female, with medical history significant for systolic congestive heart failure, who presented to the emergency department with lethargy and abdominal pain with diarrhea for the past 3 weeks. Due to hypotension, the patient received multiple boluses of isotonic saline and was started on norepinephrine. Laboratories were significant for severe digoxin toxicity (29 ng/mL), in setting of acute kidney injury. Electrocardiogram (EKG) revealed a new right bundle branch block (RBBB). She was given Digibind and her repeat digoxin level was 20 ng/mL. Repeat EKG showed resolved RBBB. This case identifies that patients with digoxin toxicity are at risk for RBBB. This is a rare finding and is not commonly recognized. Emergency medicine physicians are often the first to encounter patients with digoxin toxicity and need to be aware of such EKG findings. PMID:28104974

  5. Intermittent left bundle branch block caused by coronary vasospasm

    Science.gov (United States)

    Alhaji, Mohammad

    2013-01-01

    Intermittent left bundle branch block (LBBB) has been reported in the literature following certain conditions such as cardiac blunt trauma, myocardial infarction (MI) or exercise induced LBBB. In the majority of cases, the patients usually have underlying coronary arteries disease. LBBB often prevents the electrocardiographic diagnosis of acute MI; therefore, new LBBB in the setting of chest pain is usually treated as transmural MI. We describe a case of patient who presented with intermittent LBBB associated with chest pain, and subsequently the patient was taken to the catheterization laboratory for emergency coronary angiogram, which revealed 80% spasm in left anterior descending artery, which was totally relieved by nitroglycerin infusion. No other significant CAD was noted. PMID:23930243

  6. Right bundle branch block with revelation of changing axis deviation at the end of atrial fibrillation.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Sturiale, Mauro

    2009-11-12

    Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. Left bundle branch block is usually associated with normal or left axis deviation. Rarely the ECG shows a left bundle branch block with changing QRS morphology and changing axis deviation. There are several possible explanations for the intermittent shift in the QRS axis in the presence of complete left bundle branch block. The most plausible explanation is the coexistence of left posterior hemiblock and predivisional left bundle branch block. Intermittent right axis deviation has been rarely reported in the presence of left bundle branch block also during atrial fibrillation and with acute myocardial infarction too. Isolated left posterior hemiblock is a very rare finding and transient right axis deviation associated with a left posterior hemiblock pattern has been also rarely described associated with acute myocardial infarction. Changing axis deviation with changing bundle branch block and new-onset of atrial fibrillation during acute myocardial infarction has been also reported. Changing axis deviation with intermittent right bundle branch block in a patient admitted with acute myocardial infarction has been also described. We present a case of a right bundle branch block with revelation of changing axis deviation at the end of atrial fibrillation in a 68-year-old Italian man.

  7. Atrial fibrillation with intermittent right axis deviation in the presence of complete left bundle branch block.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Di Bella, Gianluca; Chiribiri, Amedeo

    2008-09-16

    Left bundle branch block is usually associated with normal or left axis deviation. Rarely the ecg shows an LBBB with changing QRS morphology and changing axis deviation. We describe a case of atrial fibrillation with intermittent right axis deviation in the presence of complete left bundle branch block in an 84-year-old Italian woman in the Cardiology Unit.

  8. Brugada syndrome behind complete right bundle-branch block.

    Science.gov (United States)

    Aizawa, Yoshiyasu; Takatsuki, Seiji; Sano, Motoaki; Kimura, Takehiro; Nishiyama, Nobuhiro; Fukumoto, Kotaro; Tanimoto, Yoko; Tanimoto, Kojiro; Murata, Mitsushige; Komatsu, Takashi; Mitamura, Hideo; Ogawa, Satoshi; Funazaki, Toshikazu; Sato, Masahito; Aizawa, Yoshifusa; Fukuda, Keiichi

    2013-09-03

    The characteristic ECG of Brugada syndrome (BS) can be masked by complete right bundle-branch block (CRBBB) and exposed by resolution of the block or pharmacological or pacing maneuvers. The study consisted of 11 patients who had BS and CRBBB. BS was diagnosed before the development of CRBBB, on the resolution of CRBBB, or from new characteristic ST-segment changes that could be attributable to BS. Structural heart diseases were excluded, and coronary spasm was excluded on the basis of a provocation test at catheterization. In 7 patients, BS was diagnosed before the development of CRBBB. BS was diagnosed when CRBBB resolved spontaneously (n=1) or by right ventricular pacing (n=3). The precipitating cause for the spontaneous resolution of CRBBB, however, was not apparent. On repeated ECGs, new additional upward-convex ST-segment elevation was found in V2 or V3 in 3 patients. In 2 patients, new ST-segment elevation was induced by class IC drugs. The QRS duration was more prolonged in patients with BS and CRBBB compared with age- and sex-matched controls: 170±13 versus 145±15 milliseconds in V1 and 144±19 versus 128±7 milliseconds in V5 (both Pmask BS. BS might be demonstrated by relief of CRBBB or by spontaneous or drug-induced ST-segment elevation. The prevalence, mechanism, and clinical significance of a combination of CRBBB and BS are yet to be determined.

  9. Changing axis deviation and intermittent right bundle branch block during acute myocardial infarction.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Sturiale, Mauro

    2011-03-03

    Dissimilar electrocardiographic patterns associated with right bundle branch block have been described. The prognosis of right bundle branch block in the absence of underlying cardiac disease is good but it may be poor in other cases, particularly coronary artery disease. Changing bundle branch block, new right bundle branch block, right bundle branch conduction disturbances have been reported in literature. Changing axis deviation has been reported alone or during acute myocardial infarction also associated with atrial fibrillation. Intermittent right axis deviation has been rarely reported in the presence of left bundle branch block also during atrial fibrillation and with acute myocardial infarction too. Isolated left posterior hemiblock is a very rare finding and transient right axis deviation associated with a left posterior hemiblock pattern has been also rarely described associated with acute myocardial infarction. We describe a case of changing axis deviation with intermittent right bundle branch block in a patient admitted with acute myocardial infarction. Also this case focuses attention on changing axis deviation and intermittent right bundle branch block during acute myocardial infarction. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  10. Right bundle branch block and anterior wall ST elevation myocardial infarction.

    Science.gov (United States)

    Trofin, Monica; Israel, Carsten W; Barold, S Serge

    2017-09-01

    We report the case of an acute anterior wall ST elevation myocardial infarction with new left anterior fascicular block and pre-existing right bundle branch block. Due to a wide right bundle branch block, no ST segment elevation was visible in lead V1. The left anterior fascicular block was caused by proximal occlusion of the left artery descending and disappeared after acute revascularization. However, also the R' of the right bundle branch block became significantly shorter after revascularization, dismanteling a minor ST segment elevation. The ST elevation in lead V1 in anterior wall infarction and right bundle branch block may merge with the R' and cause a further QRS widening as an "equivalent" to the ST elevation.

  11. Electrical remodelling in patients with iatrogenic left bundle branch block.

    Science.gov (United States)

    Engels, Elien B; Poels, Thomas T; Houthuizen, Patrick; de Jaegere, Peter P T; Maessen, Jos G; Vernooy, Kevin; Prinzen, Frits W

    2016-12-01

    Left bundle branch block (LBBB) is induced in approximately one-third of all transcatheter aortic valve implantation (TAVI) procedures. We investigated electrophysiological remodelling in patients with TAVI-induced LBBB. This retrospective study comprises 107 patients with initially narrow QRS complex of whom 40 did not and 67 did develop persistent LBBB after TAVI. 12-lead electrocardiograms (ECGs) taken before TAVI, within 24 hours ('acute'), and 1-12 months after TAVI ('chronic') were used to reconstruct vectorcardiograms. From these vectorcardiograms, QRS and T-wave area were calculated as comprehensive indices of depolarization and repolarization abnormalities, respectively. TAVI-induced LBBB resulted in significant acute depolarization and repolarization changes while further repolarization changes were observed with longer lasting LBBB. The amount of long-term repolarization changes (remodelling) was highly variable between patients. The change in T-wave area between acute and chronic LBBB ranged from +57% to - 77%. After dividing the LBBB cohort into tertiles based on the change in T-wave area, only baseline QRS area was larger in the tertile with no significant change in T-wave area. During longer lasting LBBB, the spatial vector gradient (SVG) changed orientation towards the direction of the QRS-vector, indicating that later-activated regions developed shorter action potential duration. This study in patients with TAVI-induced LBBB shows that repolarization changes develop within months after onset of LBBB, and that these changes are highly variable between individual patients. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For Permissions, please email: journals.permissions@oup.com.

  12. Special features of right bundle branch block in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia.

    Science.gov (United States)

    Peters, Stefan; Trümmel, Martina; Koehler, Brigitte

    2012-05-17

    We searched for special features in patients with complete and incomplete right bundle branch block diagnosed as having arrhythmogenic right ventricular cardiomyopathy/dysplasia. Whether right bundle branch block is a frequent finding in arrhythmogenic right ventricular cardiomyopathy should be studied. The question is whether special features exist such as T-wave inversions, localized right precordial QRS prolongation and r'/s ratiobundle branch block is characterized by r'/s ratiobundle branch block is characterized by ST segment elevation in right precordial leads but not by T wave inversions ≥ V4. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  13. Acute myocardial infarction and left bundle branch block with changing axis deviation.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Dattilo, Giuseppe; Sturiale, Mauro

    2012-02-09

    Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. Left bundle branch block is usually associated with normal or left axis deviation. Rarely the ECG shows a LBBB with changing QRS morphology and changing axis deviation. There are several possible explanations for the intermittent shift in the QRS axis in the presence of complete left bundle branch block. The most plausible explanation is the coexistence of left posterior hemiblock and predivisional left bundle branch block. We present a case of a left bundle branch block with changing axis deviation in a 93-year-old Italian woman admitted to the Cardiology Unit with an acute myocardial infarction. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  14. Left bundle branch block and changing axis deviation during acute myocardial infarction.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Sturiale, Mauro

    2012-03-22

    Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. Left bundle branch block is usually associated with normal or left axis deviation. Rarely the ECG shows a left bundle branch block with changing QRS morphology and changing axis deviation. We present a case of a left bundle branch block with changing axis deviation in an 86-year-old Italian man admitted to the Cardiology Unit with an acute myocardial infarction. Also this case focuses attention on left bundle branch block with changing axis deviation. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  15. Cardiac memory during rather than after termination of left bundle branch block.

    Science.gov (United States)

    Littmann, Laszlo; Proctor, Patrick A; Givens, Priscilla M

    2014-01-01

    An 83-year-old woman with chronic left bundle branch block and remote history of pacemaker implantation for intermittent AV block was hospitalized for fatigue and leg swelling. She had no cardiac complaints. Routine 12-lead electrocardiogram showed sinus rhythm with left bundle branch block. There were diffuse negative T waves in the inferior and anterolateral leads that were concordant with the QRS complexes. Echocardiogram was normal and nuclear perfusion heart scan showed no abnormality. It was noted that the negative T waves during left bundle branch block were in the exact same leads as were the deep negative QRS complexes during ventricular pacing. The electrocardiographic changes were consistent with cardiac memory. This case is unique because cardiac memory in patients with intermittent left bundle branch block typically occurs when the QRS complexes normalize and not during left bundle branch block itself. Our findings indicate that memory Ts can develop not only after normalization of wide complex rhythms but also with alternating wide complex rhythms as in the presented case where a ventricular paced rhythm was replaced by left bundle branch block. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Rate-Dependent Left Bundle-Branch Block in a Child With Propionic Aciduria

    Science.gov (United States)

    Ardoin, Kipp B.; Moodie, Douglas S.; Snyder, Christopher S.

    2009-01-01

    In most cases, a left bundle-branch block pattern on an electrocardiogram is a postoperative phenomenon. Under rare circumstances, it can be found in patients after myocardial infarction or in patients with hypertrophic cardiomyopathy, or it can be exercised induced. We describe a pediatric patient with propionic aciduria, dilated cardiomyopathy, and rate-dependent left bundle-branch block on her electrocardiogram. PMID:21603417

  17. Right bundle branch block pattern in right ventricular endocardial pacing: A needless concern?

    Directory of Open Access Journals (Sweden)

    Mangalachulli Pottammal Ranjith

    2013-01-01

    Full Text Available Right ventricular (RV endocardial pacing in permanent pacemaker implantation usually yields a left bundle branch block (LBBB pattern in surface electrocardiogram (ECG. The presence of right bundle branch block (RBBB pattern raises the suspicion of lead perforation. We report a case of RV endocardial permanent pacemaker implantation showing a RBBB pattern in ECG, suggesting a complication. However, further work-up revealed that the lead was appropriately located at the RV apex.

  18. Left bundle branch block and suspected myocardial infarction: does chronicity of the branch block matter?

    Science.gov (United States)

    Liakopoulos, Vasileios; Kellerth, Thomas; Christensen, Kjeld

    2013-06-01

    Our aim was to investigate if patients with suspected myocardial infarction (MI) and a new or presumed new left bundle branch block (nLBBB) were treated according to the ESC reperfusion guidelines and to compare them with patients having a previously known LBBB (oLBBB). Furthermore, we investigated the prevalence of ST-segment concordance in this population. Retrospective data was collected from the Swedeheart registry for patients admitted to the cardiac care unit at Örebro University Hospital with LBBB and suspected MI during 2009 and 2010. The patients were divided in two age groups; <80 or ≥80 years and analysed for LBBB chronicity (nLBBB or oLBBB), MI, and reperfusion treatment. We also compared our data with the national Swedeheart database for 2009. A total of 99 patients fulfilled the inclusion criteria. A diagnosis of MI was significantly more common in the group ≥80 years compared to the group <80 years (53.8 vs. 25%, p=0.007). The rate of MI was similar in the groups with nLBBB and oLBBB (33 and 37% respectively, p=0.912). Of the 36 patients with a final diagnosis of MI, only eight (22%) had nLBBB. Reperfusion treatment, defined as an acute coronary angiography with or without intervention, was significantly more often performed in patients with nLBBB compared to patients with oLBBB (42 vs. 8%, p<0.001). The rate of MI and reperfusion treatment did not differ between our institution and the Swedish national data. ST-concordance was present in only two cases, one of which did not suffer an MI. The proportion of patients receiving reperfusion treatment was low, but higher in nLBBB, reflecting a partial adherence to the guidelines. We found no correlation between LBBB chronicity and MI. Furthermore, only a minority of the MIs occurred in patients with nLBBB. ST-concordance was found in only one of 36 MI cases, indicating lack of sensitivity for this test.

  19. High-degree atrioventricular block in patients with preexisting bundle branch block or bundle branch block occurring during transcatheter aortic valve implantation.

    Science.gov (United States)

    Egger, Florian; Nürnberg, Michael; Rohla, Miklos; Weiss, Thomas W; Unger, Gerhard; Smetana, Peter; Geppert, Alexander; Gruber, Susanne C; Bambazek, Anton; Falkensammer, Jürgen; Waldenberger, Ferdinand R; Huber, Kurt; Freynhofer, Matthias K

    2014-12-01

    Transcatheter aortic valve implantation (TAVI) has become the standard therapy for high-risk and non-operable patients with severe aortic stenosis. However, the procedure involves several adverse effects, such as rhythm and conduction disturbances. Patients with postprocedural left bundle branch block may have an increased mortality risk, whereas patients with preprocedural right bundle branch block display a higher rate of postinterventional bradyarrhythmias. The purpose of this study was to investigate the occurrence of high-degree atrioventricular block (AVB) in patients with preexisting bundle branch block (BBB) or BBB occurring during TAVI. In this prospective single-center study, 50 consecutive patients undergoing TAVI with the Medtronic CoreValve Revalving System were included. Of these patients, 17 with preexisting BBB or BBB occurring during TAVI received a primary prophylactic permanent DDD pacemaker, programmed to the SafeR-mode and featuring dual-channel event counters as well as stored intracardiac electrograms. Pacemaker readouts and intracardiac electrograms were analyzed for the occurrence of high-degree AVB. Ten of 17 patients (58.8%) with preexisting BBB or BBB occurring during TAVI developed episodes of high-degree AVB that were immediately terminated due to switch into DDD backup pacing. In 5 of the cases (29.4%), the first documented episode of high-degree AVB occurred after hospital discharge. Mean follow-up period was 578.1 ± 294.9 days. Development of high-degree AVB is a common complication in patients with preexisting BBB or BBB occurring during TAVI. Accordingly, intensified monitoring might be reasonable, especially in patients treated with the self-expandable Medtronic CoreValve Revalving System. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  20. Right bundle branch block as a marker for interatrial septal abnormalities.

    Science.gov (United States)

    Bakalli, Aurora; Koçinaj, Dardan; Georgievska-Ismail, Ljubica; Bekteshi, Tefik; Pllana, Ejup; Sejdiu, Basri

    2012-02-01

    Interatrial septal anomalies, which include atrial septal defect, patent foramen ovale, and atrial septal aneurysm, are common disorders among adult patients. Early detection of interatrial septal anomalies is important in order to prevent haemodynamic consequences and/or thromboembolic events. Electrocardiogram offers some clues that should serve as hints for detection of interatrial abnormalities. The aim of our study was to analyse the interatrial septum by transoesophageal echocardiography in patients with electrocardiogram signs of right bundle branch block and in those without right bundle branch block. In a prospective study, 87 adult patients were included, that is, 41 with electrocardiogram signs of right bundle branch block forming the first group and 46 without right bundle branch block forming the second group. Interatrial septal anomalies were present in 80.5% of the patients with right bundle branch block, with patent foramen ovale (39.02%) being the most prevalent disorder, followed by atrial septal aneurysm (21.9%) and atrial septal defect (19.5%). Interatrial septal abnormalities were significantly more frequent in the first group compared with the second group (80.5% versus 6.5%, p value less than 0.001). Independently, patent foramen ovale was significantly more prevalent in patients with right bundle branch block (39.02% versus 4.3%, p value less than 0.001), as were atrial septal aneurysm (21.9% versus 2.2%, p value equal 0.01) and atrial septal defect (19.5% versus 0%, p value equal 0.004). Right bundle branch block should serve as a valuable indicator to motivate a detailed search for interatrial septal abnormalities.

  1. Changing axis deviation with changing bundle branch block and new-onset of atrial fibrillation during acute myocardial infarction.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Di Bella, Gianluca

    2009-03-06

    Paroxysmal atrial fibrillation is considered a frequent complication of acute myocardial infarction.It has been rarely reported alternating right and left bundle branch block associated with atrial fibrillation. It has also been rarely reported changing axis deviation with left bundle branch block also during atrial fibrillation and acute myocardial infarction. We present a case of changing axis deviation with changing bundle branch block and new-onset of atrial fibrillation in a 96-year-old Italian man with acute myocardial infarction.

  2. Absent right bundle branch block: Is it a clue of pre-excitation in Ebstein's anomaly?

    Science.gov (United States)

    Gangurde, Pranil Bhalchandra; Tidake, Abhay; Shah, Hetan; Mahajan, Ajay; Lokhandwala, Yash; Nathani, Pratap

    2016-09-01

    A 14-year-old male with a history of symptomatic tachycardia was referred for ablation. Sinus rhythm electrocardiogram was not showing any pre-excitation. Tachycardia episode was showing antidromic tachycardia with left bundle branch block morphology. Echocardiographic examination was showing Ebstein's anomaly with septal tricuspid leaflet displaced 24mm apically. The right bundle branch block (RBBB) was concealed during sinus rhythm. The RBBB was revealed with ablation of right posterior atriofascicular accessory pathway. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  3. Transient right bundle branch block in a patient with acute pulmonary embolism.

    Science.gov (United States)

    Gonzva, Jonathan; Viard, François-Valéry; Jost, Daniel; Lefort, Hugues; Tourtier, Jean-Pierre

    We report the case of an 86-year-old man found at home with acute chest pain and dyspnea. He presented some episodes of left chest pain combined with dyspnea. The physical examination revealed crackling sounds on the bases of the lungs without other anomalies. Electrocardiograms revealed a transient and complete right bundle branch block with inverted T waves in leads V1, V2, and V3. He was diagnosed with a proximal bilateral acute pulmonary embolism without acute cor pulmonale. We describe a case of a transient bundle branch block, without tachycardia or acute cor pulmonale, revealing a pulmonary embolism. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Spontaneous resolution of left bundle branch block and biventricular stimulation lead to reverse remodeling in dyssynchronopathy

    NARCIS (Netherlands)

    Kloosterman, Marielle; Rienstra, Michiel; Van Gelder, Isabelle C.; Maass, Alexander H.

    2016-01-01

    Left bundle branch block (LBBB) is considered a marker of underlying structural cardiac disease. To determine whether LBBB is cause or consequence of deterioration of left ventricular (LV) function is difficult as both are often diagnosed concomitantly. We discuss a patient where reversal of LBBB

  5. Incomplete right bundle branch block: a novel electrocardiographic marker for lone atrial fibrillation

    DEFF Research Database (Denmark)

    Nielsen, Jonas Bille; Olesen, Morten Salling; Tangø, Mogens

    2011-01-01

    Aims P-wave morphology and PR interval have both been previously associated with atrial fibrillation (AF). We hypothesized that incomplete right bundle branch block (IRBBB) would be associated with early-onset lone AF. Methods and results We conducted a case-control study comparing...

  6. Left bundle branch block as a risk factor for progression to heart failure

    DEFF Research Database (Denmark)

    Zannad, Faiez; Huvelle, Etienne; Dickstein, Kenneth

    2006-01-01

    The prevalence of conduction disturbances, particularly left bundle branch block (LBBB), is strongly correlated with age and with the presence of cardiovascular disease. LBBB has been reported to affect approximately 25% of the heart failure (HF) population and it is likely that the deleterious...

  7. Haemodynamic Benefit of Cardiac Resynchronisation Therapy Requires Left Bundle Branch Block: A Case Report

    NARCIS (Netherlands)

    Bogaard, M.D.; Leenders, G.E.H.; Doevendans, P.A.F.M.; Meine, M.

    A 55-year-old woman with dilated cardiomyopathy and rate-dependent left bundle branch block had a cardiac resynchronisation therapy (CRT) device implanted. During implantation, the maximum rate of left ventricular pressure rise (dP/dtmax) was measured invasively. This case presents

  8. Right and left bundle branch block as predictors of long-term mortality following myocardial infarction

    DEFF Research Database (Denmark)

    Lewinter, Christian; Torp-Pedersen, Christian; Cleland, John G F

    2011-01-01

    Patients with acute myocardial infarction (MI) with bundle branch block (BBB) have a poor prognosis, but distinction between left (L)- and right (R)-sided BBB is seldom made in epidemiological studies. We studied long-term mortality associated with RBBB and LBBB in the TRAndolapril Cardiac...

  9. New strict left bundle branch block criteria reflect left ventricular activation differences

    DEFF Research Database (Denmark)

    Emerek, Kasper Janus Grønn; Risum, Niels; Hjortshøj, Søren Pihlkjær

    2015-01-01

    AIMS: Pacing lead electrical delays and strict left bundle branch block (LBBB) criteria were assessed against cardiac resynchronization therapy (CRT) outcome. METHODS: Forty-nine patients with LBBB and QRS duration >130 milliseconds underwent CRT-implantation. Sensed right ventricular to left...

  10. Electrocardiographic imaging-based recognition of possible induced bundle branch blocks during transcatheter aortic valve implantations

    NARCIS (Netherlands)

    Dam, P.M. van; Proniewska, K.; Maugenest, A.M.; Mieghem, N.M. van; Maan, A.C.; Jaegere, P.P. de; Bruining, N.

    2014-01-01

    AIMS: Conventional electrocardiogram (ECG)-based diagnosis of left bundle branch block (LBBB) in patients with left ventricular hypertrophy (LVH) is ambiguous. Left ventricular hypertrophy is often seen in patients with severe aortic stenosis in which a transcatheter aortic valve implantation (TAVI)

  11. Prevalence and Prognostic Implications of Bundle Branch Block in Comatose Survivors of Out-of-Hospital Cardiac Arrest

    DEFF Research Database (Denmark)

    Grand, Johannes; Thomsen, Jakob Hartvig; Kjærgaard, Jesper

    2016-01-01

    This study reports the prevalence and prognostic impact of right bundle branch block (RBBB) and left bundle branch block (LBBB) in the admission electrocardiogram (ECG) of comatose survivors of out-of-hospital cardiac arrest (OHCA). The present study is part of the predefined electrocardiographic...

  12. [Results of randomized studies on cardiac resynchronization therapy and the reevaluation of cardiac ventricular activation in left bundle branch block].

    Science.gov (United States)

    Préda, István

    2013-05-05

    If New York Heart Association Class II-IV heart failure is present, and ejection fraction ≤35%, electrocardiographic QRS width ≥ 120 ms in the presence of left bundle branch block, cardiac resynchronization therapy is indicated. Reevaluation of the data of cardiac resynchronization trials and electrophysiologic findings in left bundle branch block provided evidence that "true" left bundle branch block requires a QRS width of ≥130 ms (in woman) and ≥140 ms (in man). In "true" left bundle branch block, after the 40th ms of the QRS notched/slurred R waves are characteristic in minimum two of I, aVL, V1, V2, V5 and V6 leads, in addition to a ≥40 ms increase of the QRS complex, as compared to the original QRS complex. In contrast, slowly and continuously widened "left bundle branch block like" QRS patterns are mostly occur in left ventricular hypertrophy or in a metabolic/infiltrative disease.

  13. Electrocardiographic markers of left ventricular systolic dysfunction in patients with left bundle branch block.

    Science.gov (United States)

    Deniz, Ali; Özmen, Çağlar; Aktaş, Halil; Berk, İlayda Gül; Deveci, Onur Sinan; Çağlıyan, Çağlar Emre; Eker Akıllı, Rabia; Kanadaşı, Mehmet; Demir, Mesut; Usal, Ayhan

    2016-01-01

    Although some patients with left bundle branch block (LBBB) have structural heart diseases, some patients with LBBB have "normal hearts". The electrocardiography (ECG) criteria of LBBB in reduced left ventricular ejection fraction (LVEF) have not been defined completely. The main purpose of this study was to differentiate patients with reduced LVEF from patients with normal left ventricular systolic function simply by analysing 12-lead ECG. Subjects admitted to our hospital with LBBB in their ECG were included in the study. The patients were categorised according to their left ventricular systolic function as group 1 (LVEF ≥ 50%) and group 2 (LVEF bundle branch, and concordance/discordance of T waves in leads V5, V6, or D1 were recorded. The ECG findings of the two groups were compared. One hundred consecutive patients with LBBB were included in the study (male/female: 56/44, age: 66 ± 15 years). In the whole group, there were 35 patients with normal left ventricular systolic function (LVEF ≥ 50%), and 65 patients had LVEF below 50%. 80% of male patients with LBBB and 45% of female patients with LBBB had their LVEF below 50% (p bundle branch was more frequent in group 2 (29% in group 1 vs. 52% in group 2, p = 0.03). Male gender, QRS duration greater than 140 ms, discordant LBBB, and residual conduction in the left bundle branch seem to be markers of reduced LVEF in patients with LBBB.

  14. Effects of an Isolated Complete Right Bundle Branch Block on Mechanical Ventricular Function.

    Science.gov (United States)

    Zhang, Qin; Xue, Minghua; Li, Zhan; Wang, Haiyan; Zhu, Lei; Liu, Xinling; Meng, Haiyan; Hou, Yinglong

    2015-12-01

    The purpose of this study was to investigate the effects of an isolated complete right bundle branch block on mechanical ventricular function. Two groups of participants were enrolled in this study: a block group, consisting of 98 patients with isolated complete right bundle branch blocks without structural heart disease, and a control group, consisting of 92 healthy adults. The diameter, end-diastolic area, end-systolic area, and right ventricular (RV) fractional area change were obtained to evaluate morphologic and systolic function by 2-dimensional sonographic technology. Systolic and diastolic velocities and time interval parameters were measured to assess mechanical ventricular performance using pulsed wave tissue Doppler imaging. Although there was no significant difference in the RV fractional area change between the patients with blocks and controls, the diameter, end-diastolic area, and end-systolic area of the RV were significantly larger in the patients with blocks (P blocks, the peak velocities during systole and early diastole and the ratio of the peak velocities during early and late diastole decreased. The block group had a prolonged pre-ejection period, electromechanical delay time, and isovolumic relaxation time, a decreased ejection time, and an increased pre-ejection period/ejection time ratio, and the myocardial performance index (Tei index) at the basal RV lateral wall was significantly increased. There were no significant differences in any echocardiographic parameters at different sites of the left ventricle. In patients with isolated complete right bundle branch blocks, systolic and diastolic functions are impaired in the RV, and follow-up is needed. © 2015 by the American Institute of Ultrasound in Medicine.

  15. Particularities of Coronary Artery Disease in Hypertensive Patients with Left Bundle Branch Block

    Science.gov (United States)

    ANGHEL, Larisa; ARSENESCU GEORGESCU, Catalina

    2014-01-01

    Objective: We mean to investigate whether the presence of hypertension could be associated with a more severe atherosclerotic coronary artery disease in patients with left bundle branch block. Material and methods: To assess the current incidence and meaning of hypertension associated with atherosclerotic coronary artery disease we performed a cross-sectional analysis that included 402 patients with left bundle branch block, admitted between January 2011 and June 2013 in the Cardiovascular Diseases Institute Iasi, Romania. Of these, 194 were hypertensive, especially grade 1 and 2; 272 patients had new or presumably new left bundle branch block on their presenting electrocardiograms. The median follow up was 7 days (hospitalization period). Results: The results of our study show that hypertensive patients were more likely to have a prior history of cardiovascular events, including myocardial infarction, angina pectoris, diabetes and obesity, with statistically significant differences. On the other hand, the normotensive patients had higher rates of current and previous smoking and congestive heart failure. Conventional coronary angiography was performed in 130 (67.01%) hypertensive patients and demonstrated that almost half (41.76%) of them have coronary artery disease, one in five patients being diagnosed with acute coronary syndromes. The majority of hypertensive patients evaluated by coronary angiography had either one or two coronary lesions (28.86%); in contrast, from 110 normotensive patients evaluated by coronary angiography, 78.36% had no vessel disease (p = 0.001). When coronary artery disease was present it was frequently localized on the left descendent artery in both groups, but with statistically significant differences (16.82% in normotensives vs. 32.47% in hypertensives, p = 0.001). With regards to systolic left ventricular function, normotensive patients were more likely to have a decreased ejection fraction (EF) bundle branch block and a clinical

  16. Comparison of left ventricular torsion and strain with biventricular pacing in patients with underlying right bundle branch block versus those with left bundle branch block.

    Science.gov (United States)

    De, Sabe; Popović, Zoran B; Verhaert, David; Dresing, Thomas; Wilkoff, Bruce; Starling, Randall; Tang, W H Wilson; Thomas, James D; Grimm, Richard A

    2015-04-01

    The benefits of biventricular pacing in patients with cardiac resynchronization therapy (CRT) remain poorly understood in those with right bundle branch block (RBBB). The aim of this study was to examine the differences in several speckle tracking-derived parameters, including left ventricular torsion and longitudinal strain with CRT on and off for patients with underlying left bundle branch block (LBBB) and RBBB. Twelve patients with CRT and RBBB were compared with a similar group of patients with underlying LBBB who were sent for evaluation and atrioventricular optimization. Echocardiographic images were acquired with biventricular pacing on and off. The 2 groups had similar baseline characteristics, including age, the ejection fraction, and QRS duration. During intrinsic conduction (CRT off), patients with LBBB had lower torsion angles than those with RBBB (2.3 ± 1.0° in those with LBBB vs 6.3 ± 1.0° in those with RBBB, p = 0.03) but trended toward improvements in torsional parameters, including torsional angle and peak untwisting velocity with CRT on, whereas these parameters worsened in patients with RBBB. Compared with CRT off, analyses of septal and lateral strain curves showed significant improvements in septal strain during 100% and 200% of systole with CRT on in patients with LBBB, whereas biventricular pacing resulted in a trend toward worsening of septal strain in patients with RBBB. Negligible changes were noted in lateral strain values. In conclusion, CRT favorably improves regional mechanics in patients with LBBB primarily involving the ventricular septum, with a negligible positive impact on cardiac function in patients with underlying RBBB. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Differential diagnosis of tachycardia with a typical left bundle branch block morphology

    Science.gov (United States)

    Neiger, Jeffrey S; Trohman, Richard G

    2011-01-01

    The evaluation of wide QRS complex tachycardias (WCT) remains a common dilemma for clinicians. Numerous algorithms exist to aid in arriving at the correct diagnosis. Unfortunately, these algorithms are difficult to remember, and overreliance on them may prevent cardiologists from understanding the mechanisms underlying these arrhythmias. One distinct subcategory of WCTs are those that present with a “typical” or “classic” left bundle branch block pattern. These tachycardias may be supraventricular or ventricular in origin and arise from functional or fixed aberrancy, bystander or participating atriofascicular pre-excitation, and bundle branch reentry. This review will describe these arrhythmias, illustrate their mechanisms, and discuss their clinical features and treatment strategies. PMID:21666813

  18. Right ventricular septal pacing in patients with right bundle branch block.

    Science.gov (United States)

    Giudici, Michael C; Abu-El-Haija, Basil; Schrumpf, Phillip E; Bhave, Prashant D; Al Khiami, Belal; Barold, Serge S

    2015-01-01

    Cardiac resynchronization therapy (CRT) has been shown to improve left ventricular (LV) function and exercise performance in patients with left bundle branch block. Patients with right bundle branch block (RBBB) do not have a similar positive response to standard CRT. We hypothesized that single site pacing of the right ventricular septum (RVS) near the proximal right bundle could restore more normal activation of the LV in RBBB patients. 78 consecutive patients (56 M, 22 F) with baseline RBBB underwent pacemaker or ICD implantation. Leads were placed in the right atrium and RVS. Baseline QRS duration was 120-220 ms (mean QRSd = 147 ms). At the optimal AV delay, the fused QRSd was 56-160 ms (mean QRSd = 112 ms). The mean decrease in QRSd was 34 ± 20.4 ms (p<0.001). RVS pacing in patients with RBBB resulted in a marked decrease in QRS duration and often normalized the ECG. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Right, but not left, bundle branch block is associated with large anteroseptal scar.

    Science.gov (United States)

    Strauss, David G; Loring, Zak; Selvester, Ronald H; Gerstenblith, Gary; Tomaselli, Gordon; Weiss, Robert G; Wagner, Galen S; Wu, Katherine C

    2013-09-10

    This study sought to test the hypothesis that right bundle branch block (RBBB) patients have larger scar size than left bundle branch block (LBBB) patients do. A proximal septal perforating branch of the left anterior descending (LAD) coronary artery most commonly perfuses the right bundle branch and left anterior fascicle, but not the left posterior fascicle. Thus, proximal LAD occlusions should cause RBBB, not LBBB. We performed electrocardiograms and magnetic resonance imaging for scar quantification in 233 patients with left ventricular (LV) ejection fraction ≤35% who were receiving primary prevention implantable cardioverter-defibrillators (ICD cohort). Scar size and location were compared among patients with RBBB, LBBB, nonspecific LV conduction delay, and QRS <120 ms. A second cohort of 20 hypertrophic cardiomyopathy patients undergoing alcohol septal ablation was studied to determine whether controlled infarction in a proximal LAD septal perforator caused RBBB or LBBB. In the ICD cohort, LV ejection fraction was similar between RBBB and LBBB patients (24.9% vs. 25.0%; p = 0.98); however, RBBB patients had significantly larger scar size (24.0% vs. 6.5%; p < 0.0001). Patients with nonspecific LV conduction delay or QRS <120 ms had intermediate scar size (12.9% and 14.4%, respectively). Those with RBBB (compared with LBBB) were more likely to have ischemic heart disease (79% vs. 29%; p < 0.0001). In the alcohol septal ablation cohort, 15 of 20 patients (75%) developed RBBB, but no patients developed LBBB. In patients with LV ejection fraction ≤35%, RBBB is associated with significantly larger scar size than LBBB is, and occlusion of a proximal LAD septal perforator causes RBBB. In contrast, LBBB is most commonly caused by nonischemic pathologies. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  20. [Intermittent left bundle branch block - reversal to normal conduction during general anesthesia].

    Science.gov (United States)

    Silva, Ana Maria Oliveira Correia da; Silva, Emília Alexandra Gaspar Lima da

    Transient changes in intraoperative cardiac conduction are uncommon. Rare cases of the development or remission of complete left bundle branch block under general and locoregional anesthesia associated with myocardial ischemia, hypertension, tachycardia, and drugs have been reported. Complete left bundle branch block is an important clinical manifestation in some chronic hypertensive patients, which may also be a sign of coronary artery disease, aortic valve disease, or underlying cardiomyopathy. Although usually permanent, it can occur intermittently depending on heart rate (when heart rate exceeds a certain critical value). This is a case of complete left bundle branch block recorded in the preoperative period of urgent surgery that reverted to normal intraoperative conduction under general anesthesia after a decrease in heart rate. It resurfaced, intermittently and in a heart-rate-dependent manner, in the early postoperative period, eventually reverting to normal conduction in a sustained manner during semi-intensive unit monitoring. The test to identify markers of cardiac muscle necrosis was negative. Pain due to the emergency surgical condition and in the early postoperative period may have been the cause of the increase in heart rate up to the critical value, causing blockage. Although the development or remission of this blockade under anesthesia is uncommon, the anesthesiologist should be alert to the possibility of its occurrence. It may be benign; however, the correct diagnosis is very important. The electrocardiographic manifestations may mask or be confused with myocardial ischemia, factors that are especially important in a patient under general anesthesia unable to report the characteristic symptoms of ischemia. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  1. Intermittent left bundle branch block - reversal to normal conduction during general anesthesia

    Directory of Open Access Journals (Sweden)

    Ana Maria Oliveira Correia da Silva

    Full Text Available Abstract Background and objectives: Transient changes in intraoperative cardiac conduction are uncommon. Rare cases of the development or remission of complete left bundle branch block under general and locoregional anesthesia associated with myocardial ischemia, hypertension, tachycardia, and drugs have been reported. Complete left bundle branch block is an important clinical manifestation in some chronic hypertensive patients, which may also be a sign of coronary artery disease, aortic valve disease, or underlying cardiomyopathy. Although usually permanent, it can occur intermittently depending on heart rate (when heart rate exceeds a certain critical value. Case report: This is a case of complete left bundle branch block recorded in the preoperative period of urgent surgery that reverted to normal intraoperative conduction under general anesthesia after a decrease in heart rate. It resurfaced, intermittently and in a heart-rate-dependent manner, in the early postoperative period, eventually reverting to normal conduction in a sustained manner during semi-intensive unit monitoring. The test to identify markers of cardiac muscle necrosis was negative. Pain due to the emergency surgical condition and in the early postoperative period may have been the cause of the increase in heart rate up to the critical value, causing blockage. Conclusions: Although the development or remission of this blockade under anesthesia is uncommon, the anesthesiologist should be alert to the possibility of its occurrence. It may be benign; however, the correct diagnosis is very important. The electrocardiographic manifestations may mask or be confused with myocardial ischemia, factors that are especially important in a patient under general anesthesia unable to report the characteristic symptoms of ischemia.

  2. Left bundle branch block, chest pain and catheterization laboratory activation: an unavoidable cascade reaction?

    Science.gov (United States)

    Ciliberti, G; Del Pinto, M; Notaristefano, F; Zingarini, G; Ambrosio, G; Cavallini, C

    2016-01-01

    Identification of acute myocardial infarction (AMI) in the presence of left bundle branch block (LBBB) remains challenging. European guidelines recommend prompt reperfusion therapy in patients with suspected ongoing myocardial ischemia and new or presumably new LBBB, whereas AHA/ACC guidelines state that LBBB should not be considered diagnostic of AMI in isolation. Sgarbossa criteria and their recent modified version with the introduction of ST/S ratio can be helpful in this setting. A clinical-instrumental algorithm to manage suspected AMI in the presence of LBBB has been recently proposed. We present five paradigmatic clinical cases. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Wellens' syndrome can indicate high-grade LAD stenosis in case of left bundle branch block.

    Science.gov (United States)

    Grautoff, Steffen

    2017-03-01

    Diagnosing acute myocardial infarction (AMI) in left bundle branch block (LBBB) is challenging. Modified Sgarbossa criteria are known to help detect AMI in LBBB. This is a report about an electrocardiogram (ECG) with Wellens' signs in combination with a pre-existing LBBB. The ECG of a patient with fluctuating chest pain showed very subtle and one day later more obvious Wellens'signs. A left anterior descending artery (LAD) stenosis was diagnosed and successfully treated. Wellens' syndrome can be diagnosed in a case of LBBB and help detect a high-grade LAD stenosis even if modified Sgarbossa criteria are not met.

  4. Spontaneous resolution of left bundle branch block and biventricular stimulation lead to reverse remodeling in dyssynchronopathy.

    Science.gov (United States)

    Kloosterman, Mariëlle; Rienstra, Michiel; Van Gelder, Isabelle C; Maass, Alexander H

    2016-01-01

    Left bundle branch block (LBBB) is considered a marker of underlying structural cardiac disease. To determine whether LBBB is cause or consequence of deterioration of left ventricular (LV) function is difficult as both are often diagnosed concomitantly. We discuss a patient where reversal of LBBB and subsequent normalization of LV function was observed after 2 different therapies, first after start of heart failure medication, and years later after implantation of a cardiac resynchronization device. This indicates that LBBB per se may result in the development of non-ischemic cardiomyopathy and that LBBB resolution can lead to reverse remodeling in dyssynchronopathy. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. New onset left bundle branch block with right axis deviation in a patient with Wegener's granulomatosis.

    Science.gov (United States)

    Khurana, C; Mazzone, P; Mandell, B

    2000-04-01

    Left bundle branch block (LBBB) is usually associated with a normal axis or left axis deviation (LAD). When it is seen in association with right axis deviation (RAD) it is felt to be a marker of diffuse advanced myocardial disease. We report a case of new onset LBBB with RAD in a patient with Wegener's granulomatosis who had an otherwise functionally and structurally normal heart. To our knowledge, this is the first case report of LBBB with RAD without severe cardiomyopathy, as well as the first case report of new onset LBBB as a result of Wegener's granulomatosis.

  6. Myocardial blood flow assessment with 82rubidium-PET imaging in patients with left bundle branch block.

    Science.gov (United States)

    Falcão, Andréa; Chalela, William; Giorgi, Maria Clementina; Imada, Rodrigo; Soares, José; Do Val, Renata; Oliveira, Marco Antonio; Izaki, Marisa; Kalil Filho, Roberto Kalil; Meneghetti, José C

    2015-11-01

    Perfusion abnormalities are frequently seen in Single Photon Emission Computed Tomography (SPECT) when a left bundle branch block is present. A few studies have shown decreased coronary flow reserve in the left anterior descending territory, regardless of the presence of coronary artery disease. We sought to investigate rubidium-82 (82Rb) positron emission tomography imaging in the assessment of myocardial blood flow and coronary flow reserve in patients with left bundle branch block. Thirty-eight patients with left bundle branch block (GI), median age 63.5 years, 22 (58%) female, 12 with coronary artery disease (≥70%; GI-A) and 26 with no evidence of significant coronary artery disease (GI-B), underwent rest-dipyridamole stress 82Rb-positron emission tomography with absolute quantitative flow measurements using Cedars-Sinai software (mL/min/g). The relative myocardial perfusion and left ventricular ejection fraction were assessed in 17 segments. These parameters were compared with those obtained from 30 patients with normal 82Rb-positron emission tomography studies and without left bundle branch block (GII). Stress myocardial blood flow and coronary flow reserve were significantly lower in GI than in GII (pbundle branch block had decreased myocardial blood flow and coronary flow reserve and coronary flow reserve assessed by 82Rb-positron emission tomography imaging may be useful in identifying coronary artery disease in patients with left bundle branch block.

  7. New-Onset Left Bundle Branch Block Induced by Transcutaneous Aortic Valve Implantation.

    Science.gov (United States)

    Massoullié, Grégoire; Bordachar, Pierre; Ellenbogen, Kenneth A; Souteyrand, Géraud; Jean, Frédéric; Combaret, Nicolas; Vorilhon, Charles; Clerfond, Guillaume; Farhat, Mehdi; Ritter, Philippe; Citron, Bernard; Lusson, Jean-R; Motreff, Pascal; Ploux, Sylvain; Eschalier, Romain

    2016-03-01

    New-onset left bundle branch block (LBBB) is a specific concern of transcutaneous aortic valve implantation (TAVI) given its estimated incidence ranging from 5% to 65%. This high rate of occurrence is dependent on the type of device used (size and shape), implantation methods, and patient co-morbidities. The appearance of an LBBB after TAVI reflects a very proximal lesion of the left bundle branch as it exits the bundle of His. At times transient, its persistence can lead to permanent pacemaker implantation in 15% to 20% of cases, most often for high-degree atrioventricular block. The management of LBBB after TAVI is currently not defined by international societies resulting in individual centers developing their own management strategy. The potential consequences of LBBB are dysrhythmias (atrioventricular block, syncope, and sudden death) and functional (heart failure) complications. Prompt postprocedural recognition and management (permanent pacemaker implantation) of patients prevents the occurrence of potential complications and may constitute the preferred approach in this frail and elderly population despite additional costs and complications of cardiac pacing. Moreover, the expansion of future indications for TAVI necessitates better identification of the predictive factors for the development of LBBB. Indeed, long-term right ventricular pacing may potentially increase the risk of developing heart failure in this population. In conclusion, it is thus imperative to not only develop new aortic prostheses with a less-deleterious impact on the conduction system but also to prescribe appropriate pacing modes in this frail population. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. [Right Bundle Branch Block, Left Bundle Branch Block, Pace Maker in Case of Acute Coronary Syndrome - is the ECG of any Value?

    Science.gov (United States)

    Grautoff, Steffen

    2017-01-01

    The 12 lead ECG is difficult to evaluate if there is a persistent right or even left bundle block or a pace maker continually stimulating the right ventricle. Despite these pre-existing or new ECG changes it might still be possible to detect variations which can hint to an ST-elevation myocardial infarction (STEMI). Diagnosing significant ST elevations in a case of right bundle block is not very challenging. If the ECG shows a left bundle block the modified Sgarbossa criteria should be used for evaluation. These criteria can also be used in a pace maker ECG. If a patient is not pacemaker-dependent the stimulation can be paused transiently to reveal changes of the ST segment. At first medical contact it can be very important to assess these changes correctly in order to classify the ECG as a STEMI. © Georg Thieme Verlag KG Stuttgart · New York.

  9. Diagnosis of myocardial infarction and ischemia in the setting of bundle branch block and cardiac pacing.

    Science.gov (United States)

    Herweg, B; Marcus, M B; Barold, S S

    2016-09-01

    The diagnosis of myocardial infarction (MI) in the presence of left bundle branch block (LBBB) or during ventricular pacing (VP) is challenging because of inherent changes in the sequence of ventricular depolarization and repolarization associated with both conditions. Although LBBB and right ventricular (RV) pacing may both produce abnormalities in the ECG, it is often possible to diagnose an acute MI (AMI) or an old MI based on selected morphologic changes. Primary ST-segment changes scoring 3 points or greater according to the Sgarbossa criteria are highly predictive of an AMI in patients with LBBB or RV pacing. The modified Sgarbossa criteria are useful for the diagnosis of AMI in patients with LBBB; however, these criteria have not yet been studied in the setting of RV pacing. Although changes of the QRS complex are not particularly sensitive for the diagnosis of an old MI in the setting of LBBB or RV pacing, the qR complex and Cabrera sign are highly specific for the presence of an old infarct. Diagnosing AMI in the setting of biventricular (BiV) pacing is challenging. To date there is minimal evidence suggesting that the traditional electrocardiographic criteria for diagnosis of AMI in bundle branch block may be applicable to patients with BiV pacing and positive QRS complexes on their ECG in lead V1. This report is a careful review of the electrocardiographic criteria facilitating the diagnosis of acute and remote MI in patients with LBBB and/or VP.

  10. Hybrid Bacterial Foraging and Particle Swarm Optimization for detecting Bundle Branch Block.

    Science.gov (United States)

    Kora, Padmavathi; Kalva, Sri Ramakrishna

    2015-01-01

    Abnormal cardiac beat identification is a key process in the detection of heart diseases. Our present study describes a procedure for the detection of left and right bundle branch block (LBBB and RBBB) Electrocardiogram (ECG) patterns. The electrical impulses that control the cardiac beat face difficulty in moving inside the heart. This problem is termed as bundle branch block (BBB). BBB makes it harder for the heart to pump blood effectively through the heart circulatory system. ECG feature extraction is a key process in detecting heart ailments. Our present study comes up with a hybrid method combining two heuristic optimization methods: Bacterial Forging Optimization (BFO) and Particle Swarm Optimization (PSO) for the feature selection of ECG signals. One of the major controlling forces of BFO algorithm is the chemotactic movement of a bacterium that models a test solution. The chemotaxis process of the BFO depends on random search directions which may lead to a delay in achieving the global optimum solution. The hybrid technique: Bacterial Forging-Particle Swarm Optimization (BFPSO) incorporates the concepts from BFO and PSO and it creates individuals in a new generation. This BFPSO method performs local search through the chemotactic movement of BFO and the global search over the entire search domain is accomplished by a PSO operator. The BFPSO feature values are given as the input for the Levenberg-Marquardt Neural Network classifier.

  11. Mechanical dyssynchrony is similar in different patterns of left bundle-branch block.

    Science.gov (United States)

    Barretto, Rodrigo Bellio de Mattos; Piegas, Leopoldo Soares; Assef, Jorge Eduardo; Melo Neto, José Francisco; Resende, Thiago Uchoa; Moreira, Dalmo Antonio; Lebihan, David Costa; França, Francisco Faustino; Meneghelo, Romeu Sérgio; Sousa, Amanda Guerra Moraes Rego

    2013-11-01

    Left bundle-branch block (LBBB) and the presence of systolic dysfunction are the major indications for cardiac resynchronization therapy (CRT). Mechanical ventricular dyssynchrony on echocardiography can help identify patients responsive to CRT. Left bundle-branch block can have different morphologic patterns. To compare the prevalence of mechanical dyssynchrony in different patterns of LBBB in patients with left systolic dysfunction. This study assessed 48 patients with ejection fraction (EF) left electrical axis deviation in the frontal plane and QRS duration > 150 ms. The patients' mean age was 60 ± 11 years, 24 were males, and mean EF was 29% ± 7%. Thirty-two had QRS > 150 ms, and22, an electrical axis between -30º and +90º. Interventricular dyssynchrony was identified in 73% of the patients, while intraventricular dyssynchrony, in 37%-98%. Patients with QRS > 150 ms had larger left atrium and ventricle, and lower EF (p Left electrical axis deviation associated with worse diastolic function and greater atrial diameter. Interventricular and intraventricular mechanical dyssynchrony (ten methods) was similar in the different LBBB patterns (p = ns). In the two different electrocardiographic patterns of LBBB analyzed, no difference regarding the presence of mechanical dyssynchrony was observed.

  12. Detection of Bundle Branch Block using Adaptive Bacterial Foraging Optimization and Neural Network

    Directory of Open Access Journals (Sweden)

    Padmavthi Kora

    2017-03-01

    Full Text Available The medical practitioners analyze the electrical activity of the human heart so as to predict various ailments by studying the data collected from the Electrocardiogram (ECG. A Bundle Branch Block (BBB is a type of heart disease which occurs when there is an obstruction along the pathway of an electrical impulse. This abnormality makes the heart beat irregular as there is an obstruction in the branches of heart, this results in pulses to travel slower than the usual. Our current study involved is to diagnose this heart problem using Adaptive Bacterial Foraging Optimization (ABFO Algorithm. The Data collected from MIT/BIH arrhythmia BBB database applied to an ABFO Algorithm for obtaining best(important feature from each ECG beat. These features later fed to Levenberg Marquardt Neural Network (LMNN based classifier. The results show the proposed classification using ABFO is better than some recent algorithms reported in the literature.

  13. Prevalence and long-term prognosis of patients with complete bundle branch block (right or left bundle branch) with normal left ventricular ejection fraction referred for stress echocardiography.

    Science.gov (United States)

    Supariwala, Azhar A; Po, Jose Ricardo F; Mohareb, Sameh; Aslam, Farhan; Kaddaha, Firas; Mian, Zainab I; Chaudhry, Farhan; Otokiti, Ahmed; Chaudhry, Farooq A

    2015-03-01

    The prognostic value of stress echocardiography (SE) in patients with complete bundle branch blocks (BBB) with normal left ventricular ejection fraction (LVEF) has not been well described. We sought to determine the prognostic value of SE in patients with BBB and normal LVEF. We analyzed 7214 patients (58 ± 14 years; 57% female) with a mean follow-up time of 9 ± 4 years. Dobutamine SE was performed in 51% of patients and exercise SE was performed in 49%. All-cause mortality data were obtained from the Social Security Death Index. There were 222 (3%) patients with right bundle branch block (RBBB) and 50 (0.7%) patients with left bundle branch block (LBBB). Patients with LBBB were 3 times more likely to have an abnormal stress test after adjusting for age, gender, mode of stress test, and coronary artery disease risk factors (OR = 3.3; 95% CI: 1.86-5.92; P < 0.001). The mortality rates were 4.5%/year for patients with LBBB, 2.5%/year for patients with RBBB, and 1.9%/year for patients without BBB (P < 0.001). Among patients with a normal SE, those with LBBB had similar mortality to those without LBBB (HR = 0.9; 95% CI: 0.4-2.2; P = 0.8). Patients with LBBB and abnormal SE had more than 2 times greater risk of all-cause mortality (HR = 2.4; 95% CI: 1.4-4.2; P = 0.002). A normal stress echocardiogram in LBBB is associated with benign prognosis while those with LBBB and abnormal SE have the worst outcomes. © 2014, Wiley Periodicals, Inc.

  14. Left bundle branch block and right axis deviation: a report of 36 cases.

    Science.gov (United States)

    Childers, R; Lupovich, S; Sochanski, M; Konarzewska, H

    2000-01-01

    Right axis deviation (RAD) with left bundle branch block (LBBB) is a rare combination. From a database of 636,000 electrocardiograms we report a series of 36 patients with this disorder. The majority of subjects had dilated cardiomyopathy with biventricular enlargement. LBBB was fixed in 21 of 36 cases. It was freshly acquired, episodic, intermittent, or physiologic in 15 of 36. The RAD was episodic in 30 of 36; it was fixed and concurrent with LBBB in only 2 cases, and never episodically concurrent. Reported for the first time here were 4 of 36 cases in which the combination of LBBB and RAD was elicited with atrial premature impulses as a rare form of QRS aberration. In one case where the combination was intermittent, a clear relationship with freshly acquired intermittent posterior fascicular block was demonstrated. The possible relationship of the deviation with variable degrees of right ventricular overload is discussed.

  15. Novel ECG criteria for right ventricular systolic dysfunction in patients with right bundle branch block.

    Science.gov (United States)

    Adams, Jonathon C; Nelson, Matthew R; Chandrasekaran, Krishnaswamy; Jahangir, Arshad; Srivathsan, Komandoor

    2013-08-20

    Altered hemodynamics of a failing right ventricle (RV) may place stress on the right bundle branch and Purkinje network, which may be evident as conduction delay on surface electrocardiogram (ECG). We hypothesized that prolonged R' duration in lead V1 would be an indicator of RV dysfunction in patients with RBBB. The Mayo Clinic Arizona echocardiography database was reviewed from 2007 to 2009 to identify patients with RV dysfunction and coexistent right bundle branch block (RBBB). Specific ECG features of RBBB were compared between the RV dysfunction cohort and a randomly selected control population. Features found to be predictive of RV dysfunction were then tested on 100 consecutive patients with RBBB on ECG between January and June 2010. In lead V1, the QRS duration was longer in the RV dysfunction cohort (164 ± 22 ms) compared to controls (148 ± 12 ms), predominantly due to R' prolongation (117 ± 27 ms vs. 87 ± 13 ms, p<.001). Retrospective analysis suggested that V1 R' duration ≥ 100 ms may be 82.3% specific for the presence of RV systolic dysfunction. When applied prospectively, V1 R' duration ≥ 100 ms yielded sensitivity and specificity of 39.0% and 82.9% respectively for detection of abnormal RV systolic function with a positive predictive value of 76.7%. Lead V1 R' duration ≥ 100 ms is predictive of RV systolic dysfunction in patients with RBBB. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  16. Right ventricular failure predicted from right bundle branch block: cardiac magnetic resonance imaging validation

    Science.gov (United States)

    Arora, Sameer; Ahmad, Ali; Sood, Mike; El Sergany, Amaar; Sacchi, Terrence; Saul, Barry; Gaglani, Rahul; Heitner, John

    2016-01-01

    Background Right ventricular (RV) failure has proven to be independently associated with adverse outcomes. Electrocardiographic parameters assessing RV function are largely unknown, making echocardiography the first line for RV function assessment. It is however, limited by geometrical assumptions and is inferior to cardiac magnetic resonance imaging (CMRI) which is widely regarded as the most accurate tool for assessing RV function. Methods We seek to determine the correlation of ECG parameters of right bundle branch block (RBBB) with RV ejection fraction (EF) and RV dimensions using the CMRI. QRS duration, R amplitude and R’ duration were obtained from precordial lead V1; S duration and amplitude were obtained from lead I and AVL. RV systolic dysfunction was defined as RV EF 100 msec to detect RV systolic dysfunction was found to be 93%. R’ duration was found to have an inverse correlation with RV EF (r=−0.49, P=0.007). Conclusions Larger RV end systolic volumes seen with RV dysfunction can affect the latter part of right bundle branch leading to prolonged R’ duration. We here found prolonged R’ duration in lead V1 to have a highly specific inverse correlation to RV systolic function. ECG can be used as an inexpensive tool for RV function assessment and should be used alongside echocardiography to evaluate RV dysfunction when CMRI is not available. PMID:27747166

  17. Frequency and prognosis of new bundle branch block induced by surgical aortic valve replacement.

    Science.gov (United States)

    Poels, Thomas T; Houthuizen, Patrick; Van Garsse, Leen A F M; Soliman Hamad, Mohammed A; Maessen, Jos G; Prinzen, Frits W; Van Straten, Albert H M

    2015-02-01

    Recently, transcatheter aortic valve implantation has been introduced, but one of its complications is left bundle branch block (LBBB), a conduction disturbance that has been associated with increased mortality. We investigated the incidence and fate of both right bundle branch block (RBBB) and LBBB after aortic valve replacement (AVR) using a retrospective analysis. We also studied the predictive value of both disorders for all-cause mortality. All patients who underwent AVR, with or without concomitant coronary artery bypass grafting surgery, between 2002 and 2010 in our centre were included. All-cause mortality was compared between patients who did and those who did not develop persistent new bundle branch block (BBB) within 7 days postoperatively. Patients were not eligible if one of their electrocardiogram (ECG) recordings prior to AVR showed a BBB or pacemaker activity. A postoperative period of 3-12 months was used to collect follow-up ECGs. Of the 2279 AVR patients, 2033 patients were eligible for analysis. After excluding patients lacking baseline or follow-up ECG (n = 269), 1764 patients remained for analysis. Early LBBB and RBBB occurred in 71 (4.0%) and 92 (5.2%) patients, respectively. At follow-up, LBBB was persistent in 29 patients (1.6%) and RBBB in 74 patients (4.2%). During a median follow-up of 4.5 (2.4-6.5) years, the mortality rate was 16.3% (n = 271) in patients without BBB, 24.1% (n = 7) in patients with persistent LBBB and 18.9% (n = 14) in patients with persistent RBBB (log-rank P = 0.49). Though, in univariate analysis, the hazard ratio for mortality was 1.54 and 1.10 for LBBB and RBBB, respectively, the small numbers precluded identifying AVR-induced LBBB and RBBB as a predictor of mortality. In the current practice of AVR, persistent postoperative LBBB and RBBB occur infrequently (∼ 5% of cases), a percentage less than half of that in current transcatheter aortic valve implantation procedures. Given the adverse effects of LBBB, the

  18. Diagnostic accuracy of computer-assisted electrocardiography in the diagnosis of left ventricular hypertrophy in left bundle branch block.

    Science.gov (United States)

    Rodríguez-Padial, Luis; Rodríguez-Picón, Blanca; Jerez-Valero, Miguel; Casares-Medrano, Julio; Akerström, Finn O; Calderon, Alberto; Barrios, Vivencio; Sarría-Santamera, Antonio; González-Juanatey, José R; Coca, Antonio; Andrés, Josep; Ruiz-Baena, Jessica

    2012-01-01

    Left ventricular hypertrophy has important prognostic implications. Although electrocardiography is the technique most often recommended in the diagnosis of hypertrophy, its diagnostic accuracy is hampered in the presence of a left bundle branch block. In 1875 consecutive patients (56±16 years) undergoing studies to rule out heart disease and/or hypertension, 2-dimensional echocardiography and electrocardiography were performed simultaneously in an outpatient clinic. Digitized electrocardiograms were interpreted using an online computer-assisted platform (ELECTROPRES). Sensitivity, specificity, likelihood ratios, and predictive values of standard electrocardiographic criteria and of some diagnostic algorithms for left ventricular hypertrophy were determined and compared with the findings in patients with neither left bundle branch block nor myocardial infarction. Left bundle branch block was present in 233 (12%) patients. Left ventricular hypertrophy was detected more frequently in patients with left bundle branch block (60% vs 31%). In patients with left bundle branch block, sensitivities were low but similar to those observed in patients without it, and ranged from 6.4% to 70.9%, whereas specificities were high, ranging from 57.6% to 100%. Positive likelihood ratios ranged from 1.33 to 4.94, and negative likelihood ratios from 0.50 to 0.98. Diagnostic algorithms, voltage-duration products, and certain compound criteria had the best sensitivities. Left ventricular hypertrophy can be diagnosed in the presence of left bundle branch block with an accuracy at least similar to that observed in patients without this conduction defect. Computer-assisted interpretation of the electrocardiogram may be useful in the diagnosis of left ventricular hypertrophy as it enables the implementation of more accurate algorithms. Copyright © 2011 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  19. Cardiac Resynchronization Therapy Relieves Intractable Angina Due to Exercise-Induced Left Bundle Branch Block Without Left Ventricular Systolic Dysfunction: A Detailed Case Study.

    Science.gov (United States)

    Czuriga, Daniel; Lim, Pitt O

    2016-05-01

    Exercise-induced left bundle branch block is rare and can be demonstrated with exercise testing. When the heart rate reaches a certain threshold, the QRS widens into left bundle branch block. This paper describes a patient with exercise-induced left bundle branch block related angina and dyspnea, who responded to cardiac resynchronization therapy. We documented the potential benefits of cardiac resynchronization therapy with a left ventricular rapid pacing study prior to its implantation. Although exercise-induced left bundle branch block is not a current indication for cardiac resynchronization therapy in patients such as ours, it could be considered when conventional drug therapy fails. © 2016 Wiley Periodicals, Inc.

  20. Comparison of the calculation QRS angle for bundle branch block detection

    Science.gov (United States)

    Goeirmanto, L.; Mengko, R.; Rajab, T. L.

    2016-04-01

    QRS angle represent condition of blood circulation in the heart. Normally QRS angle is between -30 until 90 degree. Left Axis Defiation (LAD) and Right Axis Defiation (RAD) are abnormality conditions that lead to Bundle Branch Block. QRS angle is calculated using common method from physicians and compared to mathematical method using difference amplitudos and difference areas. We analyzed the standard 12 lead electrocardiogram data from MITBIH physiobank database. All methods using lead I and lead avF produce similar QRS angle and right QRS axis quadrant. QRS angle from mathematical method using difference areas is close to common method from physician. Mathematical method using difference areas can be used as a trigger for detecting heart condition.

  1. Exercise-induced left bundle branch block: an infrequent phenomenon: Report of two cases

    Science.gov (United States)

    Said, Salah AM; Bultje-Peters, Marisa; Nijhuis, Rogier LG

    2013-01-01

    Exercise-induced left bundle branch block (EI-LBBB) is infrequent phenomenon. We present two patients with angina pectoris who developed EI-LBBB during exercise tolerance test. The first patient with typical angina pectoris had significant obstructive coronary artery disease (CAD) requiring percutaneous coronary intervention of multiple lesions including placement of drug eluting stents. The second patient had atypical chest pain without signs of CAD at all. EI-LBBB occurred at a heart rate of 80 bpm and 141 bpm in the first and second patient, respectively. EI-LBBB remained visible through the test till the recovery period in the first patient at a heart rate of 83 bpm and disappeared at 96 bpm in the second patient. Both patients with this infrequent phenomenon are discussed and the literature is reviewed. PMID:24109500

  2. Heart Failure with Transient Left Bundle Branch Block in the Setting of Left Coronary Fistula

    Directory of Open Access Journals (Sweden)

    Stephen P. Juraschek

    2011-01-01

    Full Text Available Coronary arterial fistulas are rare communications between vessels or chambers of the heart. Although cardiac symptoms associated with fistulas are well described, fistulas are seldom considered in the differential diagnosis of acute myocardial ischemia. We describe the case of a 64-year-old man who presented with left shoulder pain, signs of heart failure, and a new left bundle branch block (LBBB. Cardiac catheterization revealed a small left anterior descending (LAD-to-pulmonary artery (PA fistula. Diuresis led to subjective improvement of the patient's symptoms and within several days the LBBB resolved. We hypothesize that the coronary fistula in this patient contributed to transient ischemia of the LAD territory through a coronary steal mechanism. We elected to observe rather than repair the fistula, as his symptoms and ECG changes resolved with treatment of his heart failure.

  3. Adenosine Stress Induced Left Bundle Branch Block During Technetium-99m Tetrofosmin Myocardial Perfusion Imaging.

    Science.gov (United States)

    Jayanthi, Mohan Roop; Sasikumar, Arun; Gorla, Arun Kumar Reddy; Sood, Ashwani; Bhattacharya, Anish; Mittal, Bhagwant Rai

    2017-01-01

    The occurrence of left bundle branch block (LBBB) in electrocardiogram during exercise testing is a relatively rare finding. The incidence of LBBB during exercise testing ranges from 0.5% to 1.1%. The mechanism of exercise-induced LBBB (EI-LBBB) is poorly understood, but ischemia is a proposed etiology. Stress myocardial perfusion imaging (MPI) can be useful in patients with EI-LBBB to rule out coronary artery disease. Adenosine vasodilator stress is the preferred mode of stress in patients with LBBB for performing stress-MPI. Here we present an interesting case of adenosine-induced LBBB during stress-MPI in a 67-year-old female patient with normal coronary angiography.

  4. Significance of an isolated new right bundle branch block in a patient with chest pain.

    Science.gov (United States)

    Gilliot, Geraldine; Monney, Pierre; Muller, Olivier; Hugli, Olivier

    2015-06-08

    Chest pain is a common presenting symptom in emergency departments, and a typical manifestation of acute myocardial infarction (AMI). Recognition of ECG changes in AMI is essential for timely diagnosis and treatment. Right bundle branch block (RBBB) may be an isolated sign of AMI, and was previously considered as a criterion for fibrinolytic therapy. Since the most recent European Society of Cardiology and American Heart Association guidelines in 2013, RBBB alone is no longer considered a diagnostic criterion of AMI, even if it occurs in the context of acute chest pain, as RBBB does not usually interfere with the interpretation of ST-segment alteration. Our case illustrates an acute septal myocardial infarction with an isolated RBBB, and thus the importance of recognising this pattern in order to permit timely diagnosis and treatment. 2015 BMJ Publishing Group Ltd.

  5. The electrocardiographic characteristics of septal flash in patients with left bundle branch block.

    Science.gov (United States)

    Corteville, Ben; De Pooter, Jan; De Backer, Tine; El Haddad, Milad; Stroobandt, Roland; Timmermans, Frank

    2017-01-01

    In patients with systolic heart failure and left bundle branch block (LBBB), septal flash (SF) movement has been described by echocardiography. We evaluated the prevalence of SF in LBBB and non-LBBB patients and evaluated whether specific electrocardiographic (ECG) characteristics within LBBB are associated with the presence of SF on echocardiography. One hundred and four patients with probable LBBB on standard 12-lead ECG were selected, 40 patients with non-LBBB served as controls. Left bundle branch block and non-LBBB were defined, according to the most recent guidelines. The presence of SF was assessed by echocardiography. Strict LBBB criteria were met in 93.3% of the patients. Septal flash was present in 45.2% of LBBB patients and was not present in non-LBBB patients. This was more prevalent in patients without anterior ischaemic cardiomyopathy (ICMP) compared with those with anterior ICMP (P = 0.008). The duration of QRS was longer in SF patients compared with that of non-SF patients (P < 0.05). The presence of a mid-QRS notching in more than two consecutive leads was a good predictor for the presence of SF (P = 0.01), and when combined with an absent R-wave in lead V1, the presence of SF is very likely (P = 0.001). Our data show that SF is present in 45.2% of LBBB patients, whereas it was absent in patients with non-LBBB. Patients with SF fulfilled more LBBB criteria compared with LBBB patients without SF. Our findings raise the provocative question of whether the presence of SF identifies patients with 'true LBBB' and whether this echocardiographic finding might be considered as a selection parameter in cardiac resynchronization therapy. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

  6. Long-Term Cardiovascular Outcomes In Patients With Angina Pectoris Presenting With Bundle Branch Block

    Science.gov (United States)

    Bansilal, Sameer; Aneja, Ashish; Mathew, Verghese; Reeder, Guy S.; Smars, Peter A.; Lennon, Ryan J.; Wiste, Heather J.; Traverse, Kay; Farkouh, Michael E.

    2011-01-01

    The long-term outcomes of unselected patients with angina pectoris and a bundle branch block (BBB) on the initial electrocardiogram are not well established. The Olmsted County Chest Pain Study is a community-based cohort of 2271 consecutive patients presenting to three Olmsted County emergency departments with angina from 1985 to 1992. Patients were followed for major adverse cardiovascular events (MACE) including death, myocardial infarction, stroke and revascularization at 30 days and over a median follow-up period of 7.3 years and for mortality only through a median of 16.6 years. Cox models were used to estimate the associations between bundle branch block and cardiovascular outcomes. The mean age of the cohort on presentation was 63 years, with 58% men. MACE at 30 days occurred in 11% with RBBB, 8.8 % with LBBB and 6.4 % in patients without BBB (p=0.17). Over a median follow-up of 7.3 years, patients with BBB were at higher risk for MACE (RBBB HR 1.85, 95% CI 1.44–2.38; p<0.001 and LBBB HR 2.04, 95% CI 1.62–2.56; p<0.001) compared to those without BBB. Over a median of 16.6 years, both BBB groups had lower survival rates than patients without BBB (RBBB HR 2.19, 95% CI 1.73–2.78; p<0.001 and LBBB HR 3.32, 95% CI 2.67–4.13; p ≤ 0.001), but after adjustment for multiple risk factors, an increased risk of mortality for LBBB remained significant. In conclusion, the appearance of LBBB or RBBB in patients presenting with angina predicts adverse long-term cardiovascular outcomes compared to patients without BBB. PMID:21439535

  7. The Prognostic Significance of Right Bundle Branch Block: A Meta-analysis of Prospective Cohort Studies.

    Science.gov (United States)

    Xiong, Yunyun; Wang, Lian; Liu, Wenyan; Hankey, Graeme J; Xu, Biao; Wang, Shang

    2015-10-01

    The prognostic significance of right bundle branch block (RBBB) is inconsistent across studies. We aimed to assess the association between RBBB (in general population and patients with heart disease) and risk of all-cause mortality, cardiac death, acute myocardial infarction (MI), and heart failure (HF). RBBB may be associated with increased risk of death. PubMed, EMBASE, and the Cochrane Library up to February 2015 were searched for prospective cohort studies that reported RBBB at baseline and all-cause mortality, cardiac death, MI, and HF at follow-up. A meta-analysis of published data was undertaken primarily by means of fixed-effects models. Nineteen cohort studies including 201 437 participants were included with a mean follow-up period ranging from 1 to 246 months. For general population with RBBB, the pooled adjusted hazard ratio (HR) for all-cause mortality was 1.17 (95% confidence interval [CI]: 1.03-1.33) compared with no BBB. General population with RBBB had an increased risk of cardiac death (HR: 1.43, 95% CI: 1.17-1.74). For patients with RBBB and acute MI, the pooled risk ratio was 2.31 (95% CI: 2.13-2.49) for in-hospital mortality, 2.85 (95% CI: 2.46-3.30) for 30-day mortality, and 1.96 (95% CI: 1.59-2.42) for longer-term mortality. For acute HF patients, the pooled risk ratio of all-cause mortality was 1.11 (95% CI: 1.06-1.16), and for chronic HF patients it was 1.75 (95% CI: 1.38-2.22). Right bundle branch block is associated with an increased risk of mortality in general population and patients with heart disease. © 2015 Wiley Periodicals, Inc.

  8. [Intraoperative transient incomplete left bundle branch block in a patient with left axis deviation in pre-anesthetic electrocardiogram].

    Science.gov (United States)

    Sunaguchi, M; Imai, H; Shigemi, K; Imai, R; Ozaki, Y; Nakamura, Y; Tanaka, Y

    1998-11-01

    We encountered a case of transient incomplete left bundle branch block (TILBBB) during standard mastectomy under general anesthesia. The patient was a 40 year-old female (70 kg, 164 cm) without any abnormalities on preanesthetic examinations except -61 degrees left axis deviation in exercise electrocardiogram. Adriamycin 20 mg was administered preoperatively. After the skin incision, heart rate increased from 104 min-1 to 130 min-1 and the cardiac axis gradually rotated leftward with increasing Q wave depth on leads I and aVL. We diagnosed this as blockade of the anterior branch in the left bundle branch. After the administration of fentanyl (0.2 mg) and sevoflurane (3%), the heart rate decreased to 105 min-1 and the electrocardiogram returned to the initial wave form. This anesthetic course indicated that adriamycin had slightly damaged the cardiac muscle and inadequate anesthesia had caused tachycardia and transient left bundle branch block. Left axis deviation on preoperative exercise electrocardiogram suggests that the left bundle branch can easily be blocked with an increasing heart rate. Adequate depth of anesthesia would have prevented the increase in heart rate and abnormality in the cardiac conduction process.

  9. Transcatheter heart valve selection and permanent pacemaker implantation in patients with pre-existent right bundle branch block

    NARCIS (Netherlands)

    L. van Gils (Lennart); D. Tchetche (Didier); Lhermusier, T. (Thibault); M. Abawi (Masieh); N. Dumonteil (Nicolas); Olivares, R.R. (Ramón Rodriguez); de Nicolas, J.M. (Javier Molina-Martin); P.R. Stella (Pieter); D. Carrié (Didier); P.P.T. de Jaegere (Peter); N.M. van Mieghem (Nicolas)

    2017-01-01

    textabstractBackground-Right bundle branch block is an established predictor for new conduction disturbances and need for a permanent pacemaker (PPM) after transcatheter aortic valve replacement. The aim of the study was to evaluate the absolute rates of transcatheter aortic valve replacement

  10. Transcatheter heart valve selection and permanent pacemaker implantation in patients with pre-existent right bundle branch block

    NARCIS (Netherlands)

    van Gils, Lennart; Tchetche, Didier; Lhermusier, Thibault; Abawi, Masieh; Dumonteil, Nicolas; Rodriguez Olivares, R; de Nicolas, Javier Molina Martin; Stella, Pieter R.; Carrié, Didier; De Jaegere, Peter P.; Van Mieghem, Nicolas M.

    2017-01-01

    Background-Right bundle branch block is an established predictor for new conduction disturbances and need for a permanent pacemaker (PPM) after transcatheter aortic valve replacement. The aim of the study was to evaluate the absolute rates of transcatheter aortic valve replacement related PPM

  11. Right bundle branch block: prevalence, risk factors, and outcome in the general population: results from the Copenhagen City Heart Study.

    Science.gov (United States)

    Bussink, Barbara E; Holst, Anders G; Jespersen, Lasse; Deckers, Jaap W; Jensen, Gorm B; Prescott, Eva

    2013-01-01

    To determine the prevalence, predictors of newly acquired, and the prognostic value of right bundle branch block (RBBB) and incomplete RBBB (IRBBB) on a resting 12-lead electrocardiogram in men and women from the general population. We followed 18 441 participants included in the Copenhagen City Heart Study examined in 1976-2003 free from previous myocardial infarction (MI), chronic heart failure, and left bundle branch block through registry linkage until 2009 for all-cause mortality and cardiovascular outcomes. The prevalence of RBBB/IRBBB was higher in men (1.4%/4.7% in men vs. 0.5%/2.3% in women, P bundle branch block was associated with significantly increased all-cause and cardiovascular mortality in both genders with age-adjusted hazard ratios (HR) of 1.31 [95% confidence interval (CI), 1.11-1.54] and 1.87 (95% CI, 1.48-2.36) in the gender pooled analysis with little attenuation after multiple adjustment. Right bundle branch block was associated with increased risk of MI with an HR of 1.67 (95% CI, 1.16-2.42) and pacemaker insertion with an HR of 2.17 (95% CI, 1.22-3.86), but not with chronic heart failure (HR 1.37; 95% CI, 0.96-1.94), atrial fibrillation (HR 1.10; 95% CI, 0.73-1.67), or chronic obstructive pulmonary disease (HR 0.99; 95% CI, 0.60-1.62). The presence of IRBBB was not associated with any adverse outcome. In this cohort study, RBBB and IRBBB were two to three times more common among men than women. Right bundle branch block was associated with increased cardiovascular risk and all-cause mortality, whereas IRBBB was not. Contrary to common perception, RBBB in asymptomatic individuals should alert clinicians to cardiovascular risk.

  12. Prognostic significance of acute bundle branch block in patients with acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Mijailović Vuk

    2008-01-01

    Full Text Available Background/Aim. Acute bundle branch block (ABBB presence is associated with the increasing mortality of patients with acute myocardial infarction (AMI. The aim of this study was investigate ABBB influence with respect to in-hospital (IN and long-term mortality in patients with AIM, as well as total mortality in follow-up, the presence of in-hospital congestive cardiac insufficiency (CCI and the presence of CCI at follow-up. Methods. This study included 606 consecutive patients with AMI. A total of 415 (68.5% were males and 191 (31.5% females, mean age 64.0±11.9. After the dismissal the patients underwent 18-month follow-up period. Results. Acute bundle branch block was registered in 44 patients (7.2%, out of which 15 patients (2.4% had the left (L ABBB and 29 patients (4.8% had the right (R ABBB. The patients with ABBB showed higher proportion of IH CCI (Killip III and IV and hypotension compared with the control group (patients without ABBB. In the group of patients with ABBB β-blockers, statins, aspirin and ACE-inhibitors were less applied. All the three ABBB groups exhibited an increased IH mortality (ABBB 47.7% vs 11.2%, p < 0.01, ARBBB 55.1% vs 11.2% p < 0.01, ALBBB 33.3% vs 11.2%, p < 0.01. Follow-up mortality of the patients with ABBB and ALBBB was higher in comparison with the control group (log-rank p = 0.046 and log-rank p = 0.01, respectively, whereas the group with ARBBB did not show any differences (log-rank, p = 0.59. Conclusion. The patients with ABBB AMI are a risk group of patients that commonly exhibit both early and remote CCI accompanied by high mortality. That is the reason why this sub-group of AMI patients should receive an urgent diagnostics followed by aggressive therapeutic treatment.

    This article has been retracted. Link to the retraction 10.2298/VSP0901074U

  13. Evolving considerations in the management of patients with left bundle branch block and suspected myocardial infarction

    Science.gov (United States)

    Neeland, Ian J.; Kontos, Michael C.; de Lemos, James A.

    2012-01-01

    Patients with a suspected acute coronary syndrome (ACS) and left bundle branch block (LBBB) present a unique diagnostic and therapeutic challenge to the clinician. Although current guidelines recommend that patients with new or presumed new LBBB undergo early reperfusion therapy, data suggest that only a minority of patients with LBBB are ultimately diagnosed with acute myocardial infarction regardless of LBBB chronicity and that a significant proportion of patients will not have an occluded culprit artery at cardiac catheterization. The current treatment approach exposes a significant proportion of patients to the risks of fibrinolytic therapy without the likelihood of significant benefit, and leads to increased rates of false-positive cardiac catheterization laboratory activation, unnecessary risks, and costs. Therefore, alternative strategies to those for patients with ST-elevation myocardial infarction (STEMI) are needed to guide selection of appropriate patients with suspected ACS and LBBB for urgent reperfusion therapy. In this article, we describe the evolving epidemiology of LBBB in ACS and discuss controversies related to current clinical practice. We propose a more judicious diagnostic approach among clinically stable patients with LBBB who do not have electrocardiographic findings highly specific for STEMI. PMID:22766335

  14. Left Bundle Branch Block in Acute Cardiac Events: Insights From a 23-Year Registry.

    Science.gov (United States)

    Alkindi, Fahad; El-Menyar, Ayman; Al-Suwaidi, Jassim; Patel, Ashfaq; Gehani, Abdurrazzak A; Singh, Rajvir; Albinali, Hajar; Arabi, Abdulrahman

    2015-10-01

    Between 1991 and 2013, we evaluated the demographics, presentations, and final diagnosis of patients hospitalized with acute cardiac events and left bundle branch block (LBBB). Of 50 992 patients, 768 (1.5%) had LBBB. Compared with non-LBBB patients, patients with LBBB were mostly older, female, diabetic, and had hypertension and chronic kidney failure (CKF; P < .001 for all). Dyspnea (P < .001) and dizziness (P = .037) were more frequent in patients with LBBB. The most frequent cause of admission with LBBB was congestive heart failure (CHF; 54.2%), followed by ST-elevation myocardial infarction (STEMI; 13.3%), valvular heart disease (9.4%), unstable angina (8.3%) and Non-STEMI (7.7%). On multivariate analysis, CKF (odds ratio [OR]: 2.02, 95% confidence interval [CI]: 1.09-3.70) and LBBB (OR: 2.96, 95% CI: 2.01-4.42) were predictors of in-hospital mortality in the entire study population. Further analysis of patients with LBBB showed that CKF (OR: 2.93, 95% CI: 1.40-6.12) was the only predictor of in-hospital mortality. Regardless the presenting symptoms, CHF was the final diagnosis in most cases with LBBB. © The Author(s) 2014.

  15. Incidence and Clinical Significance of Brugada Syndrome Masked by Complete Right Bundle-Branch Block.

    Science.gov (United States)

    Wada, Tadashi; Nagase, Satoshi; Morita, Hiroshi; Nakagawa, Koji; Nishii, Nobuhiro; Nakamura, Kazufumi; Kohno, Kunihisa; Ito, Hiroshi; Kusano, Kengo F; Ohe, Tohru

    2015-01-01

    Brugada syndrome (BrS)-type electrocardiogram (ECG) is concealed by complete right bundle-branch block (CRBBB) in some cases of BrS. Clinical significance of BrS masked by CRBBB is not well known. We reviewed an ECG database of 326 BrS patients who had type 1 ECG with or without pilsicainide. "BrS masked by CRBBB" was defined on ECG as elevation of the J point at the time of CRBBB in the right precordial leads, and BrS-type J-point elevation ≥2 mm at the time of normalized QRS complex on relieved CRBBB. We identified 25 BrS patients (7.7%) with persistent (n=12) or intermittent CRBBB (n=13). Relief of CRBBB by pacing was performed in patients with persistent CRBBB. The prevalence of BrS masked by CRBBB was 3.1% (10/326 patients). Three patients had type 1 ECG, and 7 patients had type 2 or 3 ECG on relief of CRBBB. Two of these 10 patients had lethal arrhythmic events during the follow-up period (mean, 86.4±57.2 months). There was no prognostic difference between BrS masked by CRBBB and other BrS. In a small BrS population, CRBBB can completely mask typical BrS-type ECG. BrS masked by CRBBB is associated with the same risk of fatal ventricular tachyarrhythmia as other BrS.

  16. A New Formula for Estimating the True QT Interval in Left Bundle Branch Block.

    Science.gov (United States)

    Wang, Binhao; Zhang, L I; Cong, Peixin; Chu, Huimin; Liu, Ying; Liu, Jinqiu; Surkis, William; Xia, Yunlong

    2017-06-01

    QT prolongation is an independent risk factor for cardiac mortality. Left bundle branch block (LBBB) is more common in patients as they age. Widening of the QRS in LBBB causes false QT prolongation and thus makes true QT assessment difficult. We aimed to develop a simple formula to achieve a good estimate of the QT interval in the presence of LBBB. To determine the effect of QRS duration on the QT interval, QRS and QT were measured in sinus rhythm and during right ventricular apical pacing in 62 patients (age 55 ± 11 years, 60% male) undergoing electrophysiology studies. A QT formula for LBBB (QT-LBBB) was derived based on the effect of increased QRSLBBB on QTLBBB . The predictive accuracy of the QT-LBBB formula was then tested in 22 patients (age 66 ± 13 years, 64% male) with intermittent LBBB with comparisons to prior QT formulae and JT index. On average, the net increase in QRSLBBB constituted 92% of the net increase in QTLBBB . A new formula, QT-LBBB = QTLBBB - (0.86 * QRSLBBB - 71), which takes the net increase in QRSLBBB into account, best predicted the QT interval with heart rate corrected QTc in the test set of LBBB ECGs when compared to the baseline value and prior formulae. The QT-LBBB formula developed in this study best estimates the true QT interval in the presence of LBBB. It is simple and therefore can be easily utilized in clinical practice. © 2017 Wiley Periodicals, Inc.

  17. Relationship between electrocardiographic characteristics of left bundle branch block and echocardiographic findings.

    Science.gov (United States)

    Lépori, Augusto J; Mishima, Ricardo S; Rodriguez, Gonzalo; Moreyra, Eduardo A; Serra, Jose L; Tibaldi, Miguel A; Martellotto, Andres; Moreyra, Eduardo

    2015-01-01

    Complete left bundle branch block (CLBBB) is an electrocardiographic (ECG) dromotropic disorder seen in patients with various structural heart diseases and sometimes is associated with poor prognosis. Its presence confounds the application of standard ECG criteria for the diagnosis of left ventricular hypertrophy (LVH), myocardial infarction (MI) in the chronic phase, and pathologies that produce changes on ST-T segment. The aim of this investigation was to establish the relationship between CLBBB and cardiac structural abnormalities assessed by echocardiography. This observational, cross-sectional study included ECG with CLBBB from 101 patients who also had transthoracic echocardiogram (TTE) performed within 6 months. The prevalence of structural heart disease on TTE was 90%. No ECG criterion was useful to diagnose LVH since no relationship was observed between 9 different ECG signs and increased left ventricular mass index. QRS duration (p = 0.16) and left axis deviation (p = 0.09) were unrelated to reduced left ventricular ejection fraction (LVEF). Eight ECG signs proposed for the diagnosis of the chronic phase of MI demonstrated similar effectiveness, with high specificity and reduced sensitivity. CLBBB is associated with elevated prevalence of cardiac structural disease and hinders the application of common ECG criteria for the diagnosis of LVH, reduced LVEF, or chronic phase of MI. No ECG finding distinguished patients with structural heart disease from those with normal hearts. Electrocardiographic criteria for the diagnosis of MI in the chronic phase are useful when present, but when absent cannot rule it out.

  18. The effect of isolated left bundle branch block on the myocardial velocities and myocardial performance index.

    Science.gov (United States)

    Duzenli, Mehmet Akif; Ozdemir, Kurtulus; Soylu, Ahmet; Aygul, Nazif; Yazici, Mehmet; Tokac, Mehmet

    2008-03-01

    This study was planned in order to investigate the effect of left bundle branch block (LBBB) on myocardial velocities obtained by tissue Doppler echocardiography (TDE) and myocardial performance index (MPI). Subjects with LBBB (n = 61) and age-matched healthy subjects (n = 60) were enrolled in the study. Left ventricular (LV) ejection fraction (EF), mitral inflow velocities (E-wave and A-wave), isovolumetric contraction and relaxation time (ICT and IRT), ejection time (ET), and flow propagation velocity (Vp) were measured by conventional echocardiography. Systolic velocity (Sm), early and late diastolic velocities (Em and Am) and time intervals were measured by TDE. MPI was calculated by the formula (ICT + IRT)/ET. LVEF and mitral E/A ratio were similar in both groups. Vp was lower in the LBBB group than in the control group, whereas the E/Em and the E/Vp ratio was higher. LV Sm and Em/Am ratio were lower in LBBB group. Right ventricular Sm and Em/Am ratio were similar in both groups. LV mean and RV MPI were significantly increased in LBBB group. These findings obtained by TDE show that isolated LBBB impairs the ventricular functions. Both of the LV and RV dysfunctions shown by the new parameters may contribute to increased morbidity and mortality in cases with isolated LBBB.

  19. [Premature outflow tract ventricular contraction combined with complete bundle branch block: the characteristic electrocardiographic and ablation target potential features].

    Science.gov (United States)

    Di, C Y; Wan, Z; Li, K; Ding, Y S; Lin, W H

    2017-12-01

    Objective: To explore the characteristics of electrocardiogram(ECG) and target potential features of premature ventricular contraction (PVC) in patients with complete left/right bundle branch block (CL/RBBB) and compare with those without CL/RBBB. Methods: A retrospective analysis was done in 8 outflow tract PVC patients with CL/RBBB, who successfully underwent radiofrequency ablation from August 2009 to June 2017. According to the bundle branch block chamber, patients were divided into the complete right bundle branch block (CRBBB) group ( n= 4) and the complete left bundle branch block (CLBBB) group ( n= 4). The control group were those who successfully underwent ablation at the same position as the above two groups but without CL/RBBB. The characteristics of ECG and target potential features were compared among groups. Results: One case in the CRBBB group was successfully ablated in the great cardiac vein with precordial R/S>1 transition at V(1) and one case in the CLBBB group was successfully ablated in the right coronary cusp with precordial R/S>1 transition at V(2), while other 6 cases were all with precordial R/S>1 transition at lead V(4). Precordial R/S>1 transition was not later than sinus rhythm (SR) in the CLBBB group. No statistical difference was found in the QRS complex duration between SR and PVC in the CL/RBBB patients [(134.38±23.80)ms vs (156.75±25.93)ms, P> 0.05], while statistical difference was shown in the control group [(92.63±5.76)ms vs (140.25±15.97)ms, PBundle branch block can lead to misjudgment of PVC origin with CL/RBBB during sinus rhythm, thus the origin chamber of the PVC should be determined according to the mapping and ablation result.

  20. Myocardial blood flow assessment with {sup 82}rubidium-PET imaging in patients with left bundle branch block

    Energy Technology Data Exchange (ETDEWEB)

    Falcao, Andrea; Chalela, William; Giorgi, Maria Clementina; Imada, Rodrigo; Soares Junior, Jose; Do Val, Renata; Oliveira, Marco Antonio; Izaki, Marisa; Kalil Filho, Roberto; Meneghetti, Jose C., E-mail: andrea.falcao@incor.usp.br [Universidade de Sao Paulo (InCor/USP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Instituto do Coracao

    2015-11-15

    Objectives: Perfusion abnormalities are frequently seen in Single Photon Emission Computed Tomography (SPECT) when a left bundle branch block is present. A few studies have shown decreased coronary flow reserve in the left anterior descending territory, regardless of the presence of coronary artery disease. Objective: we sought to investigate rubidium-82 ({sup 82}Rb) positron emission tomography imaging in the assessment of myocardial blood flow and coronary flow reserve in patients with left bundle branch block. Methods: thirty-eight patients with left bundle branch block (GI), median age 63.5 years, 22 (58%) female, 12 with coronary artery disease (≥70%; GI-A) and 26 with no evidence of significant coronary artery disease (GI-B), underwent rest-dipyridamole stress {sup 82}Rb-positron emission tomography with absolute quantitative flow measurements using Cedars-Sinai software (mL/min/g). The relative myocardial perfusion and left ventricular ejection fraction were assessed in 17 segments. These parameters were compared with those obtained from 30 patients with normal {sup 82}Rb-positron emission tomography studies and without left bundle branch block (GII). Results: stress myocardial blood flow and coronary flow reserve were significantly lower in GI than in GII (p>0.05). The comparison of coronary flow reserve between GI-A and GI-B showed that it was different from the global coronary flow reserve (p<0.05) and the stress flow was significantly lower in the anterior than in the septal wall for both groups. Perfusion abnormalities were more prevalent in GI-A (p=0.06) and the left ventricular ejection fraction was not different between GI-A and GI-B, whereas it was lower in GI than in GII (p<0.001). Conclusion: the data confirm that patients with left bundle branch block had decreased myocardial blood flow and coronary flow reserve and coronary flow reserve assessed by {sup 82}Rb-positron emission tomography imaging may be useful in identifying coronary artery

  1. Effect of PR interval prolongation on long-term outcomes in patients with left bundle branch block vs non-left bundle branch block morphologies undergoing cardiac resynchronization therapy.

    Science.gov (United States)

    Rickard, John; Karim, Mohammad; Baranowski, Bryan; Cantillon, Daniel; Spragg, David; Tang, W H Wilson; Niebauer, Mark; Grimm, Richard; Trulock, Kevin; Wilkoff, Bruce; Varma, Niraj

    2017-10-01

    Although the influence of QRS duration (QRSd) and/or bundle branch block morphology on outcomes of cardiac resynchronization therapy (CRT) have been well studied, the effect of PR interval remains uncertain. The purpose of this study was to evaluate the impact of PR prolongation (PRp) before CRT on long-term outcomes, specifically taking into account bundle branch block morphology and QRSd. We extracted clinical data on consecutive patients undergoing CRT. Multivariate models were constructed to analyze the effect of PRp (≥200 ms) on the combined endpoint of death, heart transplant, or left ventricular assist device. Kaplan-Meier curves were constructed stratifying patients based on bundle branch block and QRSd (dichotomized by 150 ms). Of the 472 patients who met inclusion criteria, 197 (41.7%) had PR interval ≥200 ms. During follow-up (mean 5.1 ± 2.6 years) there were 214 endpoints, of which 109 (23.1%) occurred in patients with PRp. In multivariate analysis, PRp was independently associated with worsened outcomes (hazard ratio 1.34, 95% confidence interval 1.01-1.77, P = .04). When stratified by bundle branch block morphology, PRp was significantly associated with worsened outcomes (log-rank P <.001) in patients with LBBB but not in those with non-LBBB (log-rank P = .55). Among patients with LBBB, stratified by QRSd, patients without PRp had improved outcomes compared to those with PRp independent of QRSd (log-rank P <.001). PRp is an independent predictor of impaired long-term outcome after CRT among patients with LBBB but not in non-LBBB patients. Notably, among LBBB patients, PRp is a more important predictor than QRSd in assessing long-term outcomes. Copyright © 2017. Published by Elsevier Inc.

  2. Transient left bundle branch block induced by left-sided cardiac catheterization in patients without pre-existing conduction abnormalities.

    Science.gov (United States)

    Shimamoto, T; Nakata, Y; Sumiyoshi, M; Ogura, S; Takaya, J; Sakurai, H; Yamaguchi, H

    1998-02-01

    A traumatic left bundle branch block (LBBB) is uncommon in a patient with intact atrioventricular conduction. Three of our patients developed LBBB during a left-sided catheterization. Two patients suffered from angina pectoris and the other had an abdominal aneurysm. Two of them had a history of hypertension. None of the patients had ever shown any conduction abnormalities before the catheterization. The electrocardiogram just before the examination was normal in all 3 patients. LBBB was observed when a catheter was introduced into the left ventricle, and lasted 2--4 min without significant change in heart rates. Examination revealed no significant stenosis proximal to the first septal perforator and normal left ventricular contraction in all patients. One patient developed permanent LBBB 14 months later. Catheter-induced LBBB may occur easily with certain anatomical characteristics of the left bundle branch or the distal His bundle, with or without some concealed damage to the conduction system. It is important to keep this complication in mind and to pay adequate attention to patients' electrocardiograms as well as their angiographical findings, especially in those with pre-existing right bundle branch block.

  3. Protective Role of False Tendon in Subjects with Left Bundle Branch Block: A Virtual Population Study

    Science.gov (United States)

    Lange, Matthias; Di Marco, Luigi Yuri; Lekadir, Karim; Lassila, Toni; Frangi, Alejandro F.

    2016-01-01

    False tendons (FTs) are fibrous or fibromuscular bands that can be found in both the normal and abnormal human heart in various anatomical forms depending on their attachment points, tissue types, and geometrical properties. While FTs are widely considered to affect the function of the heart, their specific roles remain largely unclear and unexplored. In this paper, we present an in silico study of the ventricular activation time of the human heart in the presence of FTs. This study presents the first computational model of the human heart that includes a FT, Purkinje network, and papillary muscles. Based on this model, we perform simulations to investigate the effect of different types of FTs on hearts with the electrical conduction abnormality of a left bundle branch block (LBBB). We employ a virtual population of 70 human hearts derived from a statistical atlas, and run a total of 560 simulations to assess ventricular activation time with different FT configurations. The obtained results indicate that, in the presence of a LBBB, the FT reduces the total activation time that is abnormally augmented due to a branch block, to such an extent that surgical implant of cardiac resynchronisation devices might not be recommended by international guidelines. Specifically, the simulation results show that FTs reduce the QRS duration at least 10 ms in 80% of hearts, and up to 45 ms for FTs connecting to the ventricular free wall, suggesting a significant reduction of cardiovascular mortality risk. In further simulation studies we show the reduction in the QRS duration is more sensitive to the shape of the heart then the size of the heart or the exact location of the FT. Finally, the model suggests that FTs may contribute to reducing the activation time difference between the left and right ventricles from 12 ms to 4 ms. We conclude that FTs may provide an alternative conduction pathway that compensates for the propagation delay caused by the LBBB. Further investigation is

  4. Cardiac MRI assessment of right ventricular function: impact of right bundle branch block on the evaluation of cardiac performance parameters.

    Science.gov (United States)

    Marterer, Robert; Hongchun, Zeng; Tschauner, Sebastian; Koestenberger, Martin; Sorantin, Erich

    2015-12-01

    Right ventricular (RV) function represents a prognostic marker in patients with corrected congenital heart disease. In up to 80 % of these patients, right branch bundle block (RBBB) exists and leads to asynchronous ventricular contraction. The aim of this retrospective study was to evaluate the change of RV performance parameters considering delayed RV end-systolic contraction. RV volumes of 33 patients were assessed twice: 1) not taking account of RBBB (group I), and 2) considering RBBB (group II). According to the RV ejection fraction (EF) for both groups, RV function was classified in different categories (>50 % = normal, 40-50 % = mildly-, 30-40 % = moderately-, branch bundle block leads to an asynchronous ventricular contraction • In CMR, a delayed right ventricular contraction due to RBBB can be detected • Ignoring RV physiology in RBBB patients leads to underscoring of RV performance.

  5. A Novel Pacing Strategy With Low and Stable Output: Pacing the Left Bundle Branch Immediately Beyond the Conduction Block.

    Science.gov (United States)

    Huang, Weijian; Su, Lan; Wu, Shengjie; Xu, Lei; Xiao, Fangyi; Zhou, Xiaohong; Ellenbogen, Kenneth A

    2017-12-01

    This report demonstrates the feasibility of pacing the left bundle branch (LBB) immediately beyond the conduction block to functionally restore the impaired His-Purkinje conduction system in a patient with heart failure and left bundle branch block (LBBB). The pacing required only a low pacing output (0.5 volts/0.5 ms) to correct the LBBB with accompanying right BBB on the electrocardiogram. Over 1-year of follow-up, the patient had a significant improvement in clinical outcome and echocardiographic measurements. The case shows a novel pacing strategy for patients with BBB that affects many patients with heart failure. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  6. Exercise Induced Left Bundle Branch Block Treated with Cardiac Rehabilitation: A Case Report and a Review of the Literature

    Science.gov (United States)

    Anderson, Nathan S.; Ramirez, Alexies; Slim, Ahmad; Malik, Jamil

    2014-01-01

    Exercise induced bundle branch block is a rare observation in exercise testing, accounting for 0.5 percent of exercise tests. The best treatment of this condition and its association with coronary disease remain unclear. We describe a case associated with normal coronary arteries which was successfully treated with exercise training. While this treatment has been used previously, our case has a longer followup than previously reported and demonstrates that the treatment is not durable in the absence of continued exercise. PMID:24716091

  7. Prognostic Implication of the QRS Axis and its Association with Myocardial Scarring in Patients with Left Bundle Branch Block

    OpenAIRE

    Park, Chan Soon; Cha, Myung-jin; Choi, Eue-Keun; Oh, Seil

    2017-01-01

    Background and Objectives Left bundle branch block (LBBB) with left axis deviation (LAD) has a worse prognosis than LBBB with a normal axis, and myocardial dysfunction has been suggested as a cause of left axis deviation. This study investigated the prognostic significance of the QRS axis in patients with LBBB and analyzed its relationship with the amount of myocardial scarring. Subjects and Methods A total of 829 patients were diagnosed with LBBB at Seoul National University Hospital from Oc...

  8. Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block

    Science.gov (United States)

    Cabeda, Estêvan Vieira; Falcão, Andréa Maria Gomes; Soares Jr., José; Rochitte, Carlos Eduardo; Nomura, César Higa; Ávila, Luiz Francisco Rodrigues; Parga, José Rodrigues

    2015-01-01

    Background Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB). Objective To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP) by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA) (stenosis ≥ 70%) as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA) and compare the results with those of single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy. Methods Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography. Independent examiners performed per-patient and per-coronary territory assessments. All patients gave written informed consent to participate in the study that was approved by the institution’s ethics committee. Results The patients’ mean age was 62 ± 10 years. The mean dose of radiation for the tomography protocol was 9.3 ± 4.6 mSv. With regard to CTP, the per-patient values for sensitivity, specificity, positive and negative predictive values, and accuracy were 86%, 81%, 80%, 87%, and 83%, respectively (p = 0.001). The per-territory values were 63%, 86%, 65%, 84%, and 79%, respectively (p < 0.001). In both analyses, the addition of CTP to CTA achieved higher diagnostic accuracy for detecting myocardial ischemia than SPECT (p < 0.001). Conclusion The use of the stress tomography protocol is feasible and has good diagnostic accuracy for assessing myocardial ischemia in patients with LBBB. PMID:26421532

  9. Prognostic and clinical significance of newly acquired complete right bundle branch block in Japan Airline pilots.

    Science.gov (United States)

    Taniguchi, Masayuki; Nakano, Hajime; Kuwahara, Koichiro; Masuda, Izuru; Okawa, Yasuhiro; Miyazaki, Hiroshi; Okoshi, Hirofumi; Kaji, Masanobu; Noguchi, Yoshiko; Asukata, Ichiro

    2003-01-01

    The purpose of this study was to evaluate the prognostic and clinical significance of newly acquired complete right bundle branch block (CRBBB) in airline pilots. This study included pilots with acquired CRBBB, identified from a group of over 2,700 Japan Airline pilots. When the pilots applied for employment, a past medical history, physical examination, electrocardiogram, and chest radiograph were obtained. The pilots with ECG abnormality including CRBBB were not included in the study because of hiring requirements. Thirty-six pilots with CRBBB were identified between 1983 and 2002. All pilots with CRBBB were evaluated for the presence of ischemic heart disease by treadmill exercise testing, echocardiogram and exercise thallium scintigraphy. Twelve individuals underwent coronary angiography. The mean age of pilots was 44.4 +/- 5.8 years. The mean observation period was 10.9 +/- 5.7 years. For each of the 36 study subjects, Holter electrocardiogram and echocardiogram were obtained every 6 months after the CRBBB was detected. Exercise stress testing was performed every year. Exercise thallium scintigraphy was performed every 2 years to detect ischemic heart disease. During the observation period, two pilots stopped flying temporarily because of frequent ventricular premature beats and one pilot stopped flying permanentaly because of atrial fibrillation. During the follow-up period, no cardiovascular events were observed in pilots with CRBBB who had no underlying ischemic heart disease. Acquired CRBBB does not confer a poor prognosis, particularly in young men working as a pilot if there is no evidence of ischemia on exercise stress testing, echocardiography and exercise thallium scintigraphy.

  10. Cardiovascular magnetic resonance features of mechanical dyssynchrony in patients with left bundle branch block.

    Science.gov (United States)

    Revah, Giselle; Wu, Vincent; Huntjens, Peter R; Piekarski, Eve; Chyou, Janice Y; Axel, Leon

    2016-09-01

    Patients with left bundle branch block (LBBB) can exhibit mechanical dyssynchrony which may contribute to heart failure; such patients may benefit from cardiac resynchronization treatment (CRT). While cardiac magnetic resonance imaging (CMR) has become a common part of heart failure work-up, CMR features of mechanical dyssynchrony in patients with LBBB have not been well characterized. This study aims to investigate the potential of CMR to characterize mechanical features of LBBB. CMR examinations from 43 patients with LBBB on their electrocardiogram, but without significant focal structural abnormalities, and from 43 age- and gender-matched normal controls were retrospectively reviewed. The following mechanical features of LBBB were evaluated: septal flash (SF), apical rocking (AR), delayed aortic valve opening measured relative to both end-diastole (AVO ED ) and pulmonic valve opening (AVO PVO ), delayed left-ventricular (LV) free-wall contraction, and curvatures of the septum and LV free-wall. Septal displacement curves were also generated, using feature-tracking techniques. The echocardiographic findings of LBBB were also reviewed in those subjects for whom they were available. LBBB was significantly associated with the presence of SF and AR; within the LBBB group, 79 % had SF and 65 % had AR. Delayed AVO ED , AVO PVO , and delayed LV free-wall contraction were significantly associated with LBBB. AVO ED and AVO PVO positively correlated with QRS duration and negatively correlated with ejection fraction. Hearts with electrocardiographic evidence of LBBB showed lower septal-to-LV free-wall curvature ratios at end-diastole compared to normal controls. CMR can be used to identify and evaluate mechanical dyssynchrony in patients with LBBB. None of the normal controls showed the mechanical features associated with LBBB. Moreover, not all patients with LBBB showed the same degree of mechanical dyssynchrony, which could have implications for CRT.

  11. Left bundle branch block in Duchenne muscular dystrophy: Prevalence, genetic relationship and prognosis.

    Science.gov (United States)

    Fayssoil, Abdallah; Ben Yaou, Rabah; Ogna, Adam; Chaffaut, Cendrine; Leturcq, France; Nardi, Olivier; Wahbi, Karim; Duboc, Denis; Lofaso, Frederic; Prigent, Helene; Clair, Bernard; Crenn, Pascal; Nicolas, Guillaume; Laforet, Pascal; Behin, Anthony; Chevret, Sylvie; Orlikowski, David; Annane, Djillali

    2018-01-01

    Duchenne muscular dystrophy (DMD) is an inherited myogenic disorder due to mutations in the dystrophin gene on chromosome Xp21.1. We designed this study to determine the prevalence of left bundle branch block (LBBB), whether there is a relationship between LBBB and genetic pattern, and to assess predictive factors for acute cardiac events and mortality in adult DMD patients. We reviewed the charts of DMD followed at the Home Mechanical Ventilation Unit of the Raymond Poincare University Hospital. A total of 121 patients, aged from 18 to 41 years have been included in our study. Median vital capacity (VC) was 12% [7; 19.5] of predicted. Almost all patients were on home mechanical ventilation (95%). LBBB was present in 15 patients (13%); among them, 10 disclosed exonic deletions. After a median follow up of 6 years, 21 patients (17%) experienced acute heart failure (AHF), 7 patients (6%) supraventricular arrhythmia, 3 patients (2.4%) ventricular tachycardia, 4 patients (3%) significant electrical disturbances. LBBB was significantly associated with cardiac events (OR = 12.7; 95%CI [3.78-42.7]; p <0.0001) and mortality (OR = 4.4; 95%CI [1.44-13.7]; p 0.009). Presence of residual dystrophin protein was not associated with significant less cardiac events. Age and LVEF were also predictive factors for cardiac events and mortality. LBBB is relatively frequent in DMD and is a major predictive factor for cardiac events and mortality. Presence of residual dystrophin protein was not associated with a lower incidence of cardiac events.

  12. New formula for evaluation of the QT interval in patients with left bundle branch block.

    Science.gov (United States)

    Bogossian, Harilaos; Frommeyer, Gerrit; Ninios, Ilias; Hasan, Fuad; Nguyen, Quy Suu; Karosiene, Zana; Mijic, Dejan; Kloppe, Axel; Suleiman, Hawal; Bandorski, Dirk; Seyfarth, Melchior; Lemke, Bernd; Eckardt, Lars; Zarse, Markus

    2014-12-01

    Left bundle branch block (LBBB) and QT prolongation both are associated with a worse prognosis. LBBB lengthens the QT interval. To date it is not known whether QT prolongation during LBBB differs in repolarization from QT prolongation during narrow QRS. The purpose of the present proof-of-concept-study was to develop a formula that allows comparison of the adjusted QT interval during LBBB with reference values and thereby allows interpretation of the QT interval irrespective of QRS widening. Sixty consecutive patients with sinus rhythm (SR) and narrow QRS underwent electrophysiologic study for ablation. In all patients, the intrinsic QRS ,QT, and JT times were measured during SR, and ventricular pacing from both the right ventricular apex (RVA) and the right ventricular outflow tract (RVOT) caused LBBB. We determined prolongation of the QT during as compared to SR (ΔQT). ΔQT was then divided by the QRS length during pacing QRS (QRSb). This describes the percentage of the QRS duration at LBBB, which must be subtracted from the measured QT (QTb) to determine the modified QT interval (QTm). The ratio of ΔQT to paced QRS was calculated as 48.3% (RVA) and 48.8% (RVOT) (mean 48.5%). The ratio intrinsic of JTi to paced JT was 1.0055 (RVA) and 1.0087 (RVOT). There was no significant difference in intrinsic JT vs paced JT (P = .2). Right ventricular pacing causes prolongation of the QT due to a paced LBBB without prolongation of the JT time. In our study, we showed that QT prolongation caused by LBBB constitutes 48.5% of the QRS width. This is the value that must be subtracted from the measured QT in LBBB in order to estimate the modified QT. Thus, the resulting formula for "modified QT" estimation in LBBB is QTm = QTb - 48.5% * (QRSb). Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  13. Exercise left ventricular ejection fraction predicts events in right bundle branch block.

    Science.gov (United States)

    Peteiro, Jesús; Bouzas-Mosquera, Alberto; Broullón, Javier; Yañez, Juan; Martinez, Dolores; Vazquez, Jose Manuel

    2016-01-01

    Interpretation of the electrocardiogram (ECG) during exercise is not easy in patients with right bundle branch block (RBBB). Also, the value of exercise echocardiography (ExE) for predicting outcome in them has not been addressed. We sought to assess its prognostic value in patients with RBBB and known/suspected coronary disease. Retrospective analysis of data on 703 patients with RBBB who were submitted to a clinically-indicated ExE. The end points were overall mortality and combined myocardial infarction and cardiovascular mortality. During follow-up (4.1 ± 4.5 years) there were 130 deaths and 108 combined events. Independent predictors of combined events were history of coronary artery disease (hazard ratio [HR] = 2.37, 95% Confidence Interval [CI] = 1.24-4.52, p = 0.009) resting wall motion score index (HR = 2.14, 95% CI = 1.12-4.10, p = 0.02), metabolic equivalents (HR = 0.89, 95% CI = 0.93-0.97, p = 0.007), Δ in double product with exercise (HR = 0.96, 95% CI = 0.92-1.00, p = 0.036) and Δ in left ventricular ejection fraction (LVEF) with exercise (HR = 0.97, 95% CI = 0.94-0.99, p = 0.01). Neither positive clinical nor ECG exercise testing was predictive. Combined event rates were 3.3% in patients with ΔLVEF > 5%, 4.7% in those with ΔLVEF between 1-5% and 8.2% in those with no increase (Δ < 1%). A decrease in LVEF during exercise is predictive of serious events in patients with RBBB.

  14. Automatic QRS Selvester scoring system in patients with left bundle branch block.

    Science.gov (United States)

    Xia, Xiaojuan; Wieslander, Björn; Strauss, David G; Wagner, Galen S; Zareba, Wojciech; Moss, Arthur J; Couderc, Jean-Philippe

    2016-02-01

    The Selvester QRS scoring system uses quantitative criteria from the standard 12-lead electrocardiogram (ECG) to estimate the myocardial scar size of patients, including those with left bundle branch block (LBBB). Automation of the scoring system could facilitate the clinical use of this technique which requires a set of multiple QRS patterns to be identified and measured. We developed a series of algorithms to automatically detect and measure the QRS parameters required for Selvester scoring. The 'QUantitative and Automatic REport of Selvester Score' was designed specifically for the analysis of ECGs from patients meeting new strict criteria for complete LBBB. The algorithms were designed using a training (n = 36) and a validation (n = 180) set of ECGs, consisting of signal-averaged 12-lead ECGs (1000 Hz sampling) recorded from 216 LBBB patients from the MADIT-CRT. We assessed the performance of the methods using expert manually adjudicated ECGs. The average of absolute differences between automatic and adjudicated Selvester scoring was 1.2 ± 1.5 points. The range of average differences for continuous measurements of wave locations and interval durations varied between 0 and 6 ms. Erroneous detection of Q, R, S, R', and S' waves (oversensed or missed) were 3, 1, 1, 16, and 6%, respectively. Seven percent of notches detected in the first 40 ms were misdetected. We propose an efficient computerized method for the automatic measurement of the Selvester score in patients with the strict LBBB. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  15. Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block

    Directory of Open Access Journals (Sweden)

    Estêvan Vieira Cabeda

    2015-01-01

    Full Text Available AbstractBackground:Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB.Objective:To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA (stenosis ≥ 70% as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA and compare the results with those of single photon emission computed tomography (SPECT myocardial perfusion scintigraphy.Methods:Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography. Independent examiners performed per-patient and per-coronary territory assessments. All patients gave written informed consent to participate in the study that was approved by the institution’s ethics committee.Results:The patients’ mean age was 62 ± 10 years. The mean dose of radiation for the tomography protocol was 9.3 ± 4.6 mSv. With regard to CTP, the per-patient values for sensitivity, specificity, positive and negative predictive values, and accuracy were 86%, 81%, 80%, 87%, and 83%, respectively (p = 0.001. The per-territory values were 63%, 86%, 65%, 84%, and 79%, respectively (p < 0.001. In both analyses, the addition of CTP to CTA achieved higher diagnostic accuracy for detecting myocardial ischemia than SPECT (p < 0.001.Conclusion:The use of the stress tomography protocol is feasible and has good diagnostic accuracy for assessing myocardial ischemia in patients with LBBB.

  16. Validation of an automatic diagnosis of strict left bundle branch block criteria using 12-lead electrocardiograms.

    Science.gov (United States)

    Xia, Xiaojuan; Ruwald, Anne-Christine; Ruwald, Martin H; Ugoeke, Nene; Szepietowska, Barbara; Kutyifa, Valentina; Aktas, Mehmet K; Thomsen, Poul Erik B; Zareba, Wojciech; Moss, Arthur J; Couderc, Jean-Philippe

    2017-03-01

    Strict left bundle branch block (LBBB) criteria were recently proposed to identify LBBB patients to benefit most from cardiac resynchronization therapy (CRT). The aim of our study was to automate identification of strict LBBB in order to facilitate its broader application. We developed a series of algorithms to automatically detect and measure parameters required for strict LBBB criteria and proposed a definition of QRS notch detection. The algorithms were developed using training (n = 20) and validation (n = 592) sets consisting of signal-averaged 12-lead ECGs (1,000 Hz sampling) recorded from 612 LBBB patients from Multicenter Automatic Defibrillator Implantation Trial-CRT. Four trained clinicians independently performed adjudication on 148 different ECGs for comparing automatic and manually adjudicated results, in addition to 13 ECGs for evaluation of intraobserver variability and 32 ECGs for interobserver variability. We assessed the performance of the automated algorithms using manually adjudicated ECGs as references. Overall sensitivity and specificity for detecting strict LBBB were 95% and 86%, respectively. The mean absolute deviation (MAD) of QRS duration and notch/slur locations for the automated method versus the manual method was below 1 ms, and MAD values were lower than 2 ms for interobserver and intraobserver variability. Sensitivity and specificity for detecting notch and slur locations were 87% and 96% for notches and 78% and 90% for slurs using the automatic method. In addition 95% and 93% agreements for notches and 90% and 88% agreements for slurs were reached for intra- and interobserver. The proposed algorithms automatically measure QRS features for the diagnosis of strict LBBB. Our study shows good performance in reference to manual results. © 2016 Wiley Periodicals, Inc.

  17. Left bundle branch block in Duchenne muscular dystrophy: Prevalence, genetic relationship and prognosis

    Science.gov (United States)

    Ben Yaou, Rabah; Ogna, Adam; Chaffaut, Cendrine; Leturcq, France; Nardi, Olivier; Wahbi, Karim; Duboc, Denis; Lofaso, Frederic; Prigent, Helene; Clair, Bernard; Crenn, Pascal; Nicolas, Guillaume; Laforet, Pascal; Behin, Anthony; Chevret, Sylvie; Orlikowski, David; Annane, Djillali

    2018-01-01

    Background Duchenne muscular dystrophy (DMD) is an inherited myogenic disorder due to mutations in the dystrophin gene on chromosome Xp21.1. We designed this study to determine the prevalence of left bundle branch block (LBBB), whether there is a relationship between LBBB and genetic pattern, and to assess predictive factors for acute cardiac events and mortality in adult DMD patients. Methods We reviewed the charts of DMD followed at the Home Mechanical Ventilation Unit of the Raymond Poincare University Hospital. Results A total of 121 patients, aged from 18 to 41 years have been included in our study. Median vital capacity (VC) was 12% [7; 19.5] of predicted. Almost all patients were on home mechanical ventilation (95%). LBBB was present in 15 patients (13%); among them, 10 disclosed exonic deletions. After a median follow up of 6 years, 21 patients (17%) experienced acute heart failure (AHF), 7 patients (6%) supraventricular arrhythmia, 3 patients (2.4%) ventricular tachycardia, 4 patients (3%) significant electrical disturbances. LBBB was significantly associated with cardiac events (OR = 12.7; 95%CI [3.78–42.7]; p <0.0001) and mortality (OR = 4.4; 95%CI [1.44–13.7]; p 0.009). Presence of residual dystrophin protein was not associated with significant less cardiac events. Age and LVEF were also predictive factors for cardiac events and mortality. Conclusion LBBB is relatively frequent in DMD and is a major predictive factor for cardiac events and mortality. Presence of residual dystrophin protein was not associated with a lower incidence of cardiac events. PMID:29304097

  18. Right bundle branch block and middle septal fiber block with or without left anterior fascicular block manifested as aberrant conduction in apparent healthy individuals: Electro-vectorcardiographic characterization.

    Science.gov (United States)

    Acunzo, Rafael S; Konopka, Isabel V; Sanchéz, Rubén A; Pizzarelli, Norma; Wells, Fernanda Comas; Baranchuk, Adrian; Chiale, Pablo A

    2013-01-01

    Right bundle branch block (RBBB) evident in the precordial ECG leads may be associated with evidence of left bundle branch involvement in the limb leads. Any of the components of the left bundle can be involved, and this complex interventricular conduction abnormality has previously been described in patients with underlying heart disease. To analyze the electro-vectorcardiographic manifestations of RBBB with left middle septal fiber block (LMSFB), with or without left anterior fascicular block (LAFB) in premature atrial beats of patients without apparent structural heart disease. Twelve patients (8 men/4 women; mean age: 32±8years) with premature atrial contractions with this conduction abnormality were included. Surface 12 simultaneous lead ECG recordings and the corresponding vectorcardiographic loops were analyzed. The QRS complexes with RBBB and also LMSFB persisted for between 150 and 190ms. There were no q waves in lead I. The maximum spatial vector (72-86ms) was directed posteriorly, superiorly, and leftward, and the terminal forces were oriented anteriorly, inferiorly and rightward. In 10 patients, small q waves were apparent in leads V1-V2 and the frontal QRS axis was -60° and -70°, with the 46ms vector located at -50°±5. All of these patients most probably had LAFB in addition to LMSFB. In two patients, the initial electrical forces were directed anteriorly, inferiorly, and leftward, and the 46ms vector axis in the frontal plane was 6° and 11°, respectively, indicating absence of LAFB. The combination of RBBB and LMSFB occurring in patients without apparent structural heart disease may be related to the simultaneous occurrence of block of conduction through these components of the Purkinje network. The anterior fascicle of the left bundle may also be involved. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Complete left bundle branch block with left QRS axis deviation: defining its clinical importance.

    Science.gov (United States)

    Parharidis, G; Nouskas, J; Efthimiadis, G; Styliadis, J; Gemitzis, K; Hatzimiltiadis, S; Karoulas, T; Tsifodimos, D

    1997-01-01

    Aim of this study was to elucidate the diagnostic significance of left axis deviation (LAD) in patients (pts) with chronic (> 6 months) left bundle branch block (LBBB). We retrospectively studied 2094 consecutive pts who underwent cardiac catheterization. All pts had left heart catheterization and coronary angiography, whereas right heart catheterization or endomyocardial biopsy were performed on indication. Our study group consisted of 43 pts with LBBB (29 men, 14 women, mean age 60.3 +/- 7.9 years). Pts with acute myocardial infarction or prior high degree AV-block were excluded. Initial evaluation included history, physical examination, chest X-ray, serial ECGs, 2D-echo and Doppler studies. ECG-criteria for LBBB were a QRS duration of > 0.12 secs, a predominantly negative QRS deflection in V1 and a widened R-wave in V6. LAD was considered present when the mean frontal QRS axis was between -30 degrees and -90 degrees. The mean frontal QRS axis was considered normal if it was between -29 degrees and +90 degrees. Twenty-nine pts had normal axis and 14 had LAD. According to angiographic data, among coronary disease pts, 12 (31.48%) had normal axis and 4 (28.57%) LAD (p = 0.041). Among mitral valve disease pts, 3 (10.35%) had normal axis and none LAD. Among pts with aortic valve disease, I (3.45%) had normal axis and 8 (57.15%) LAD (p = 0.0001). Among pts with dilated cardiomyopathy, 2 (6.9%) had normal axis and 1 (7.14%) LAD. Among pts with no organic heart disease, 11 (37.93%) had normal axis and 1 (7.14%) LAD (p = 0.035). The presence of LAD had a 41.9% sensitivity and a 91.6% specificity for the presence of organic heart disease. These findings point towards a statistically significant difference in the presence of organic heart disease in LBBB pts with LAD compared to normals. Aortic valve disease in LBBB pts seems to be frequently accompanied by LAD.

  20. Usefulness of QRS axis change to predict mortality in patients with left bundle branch block.

    Science.gov (United States)

    Patel, Parin J; Verdino, Ralph J

    2013-08-01

    QRS duration correlates with poor prognosis in patients with left bundle branch block (LBBB), but the importance of left-axis deviation (LAD) is not well established. To determine if LAD confers a mortality risk in patients with LBBB, a single-center, retrospective, population-based cohort study was conducted. Included were all patients at 1 hospital with LBBB on electrocardiography from 1995 to 2005 over a 17-year follow-up period (n = 2,794, median follow-up duration 20 months, interquartile range 6 to 64). Half of all patients with LBBB had LAD. The all-cause mortality rate in the entire cohort was 15%. LAD was not associated with mortality, either as a single outcome (odds ratio [OR] 1.1, 95% confidence interval [CI] 0.88 to 1.3, p = 0.50) or in time-to-event analysis (p = 0.40). Significant risk factors for mortality included high creatinine (OR 1.2, 95% CI 1.1 to 1.3), low hemoglobin (OR 1.2, 95% CI 1.1 to 1.3), history of atrial fibrillation (OR 1.6, 95% CI 1.3 to 2.1), electrocardiographic evidence of previous infarct (OR 1.5, 95% CI 1.2 to 1.9), and history of ventricular tachycardia (OR 1.4, 95% CI 1.0 to 1.9). On bivariate analysis, LAD was associated with atrial fibrillation, ventricular tachycardia, age, and congestive heart failure. Patients with LBBB who converted from normal axis to LAD had significantly higher mortality in time-to-event analysis (p = 0.02). In conclusion, in patients with LBBB, LAD does not confer significant mortality risk. However, those with normal axis who developed LAD during the study period had significantly higher mortality. Perhaps when LBBB and LAD develop concurrently, there is no increased risk over baseline LBBB development, but it may herald a worse prognosis if LAD develops against the background of previous LBBB, from an unknown mechanism. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Primary angioplasty in acute myocardial infarction with right bundle branch block: should new onset right bundle branch block be added to future guidelines as an indication for reperfusion therapy?

    Science.gov (United States)

    Widimsky, Petr; Roháč, Filip; Štásek, Josef; Kala, Petr; Rokyta, Richard; Kuzmanov, Boyko; Jakl, Martin; Poloczek, Martin; Kaňovský, Jan; Bernat, Ivo; Hlinomaz, Ota; Bělohlávek, Jan; Král, Ales; Mrázek, Vratislav; Grigorov, Vladimir; Djambazov, Slaveyko; Petr, Robert; Knot, Jiri; Bílková, Dana; Fischerová, Michaela; Vondrák, Karel; Malý, Marek; Lorencová, Alena

    2012-01-01

    Aims The current guidelines recommend reperfusion therapy in acute myocardial infarction (AMI) with ST-segment elevation or left bundle branch block (LBBB). Surprisingly, the right bundle branch block (RBBB) is not listed as an indication for reperfusion therapy. This study analysed patients with AMI presenting with RBBB [with or without left anterior hemiblock (LAH) or left posterior hemiblock (LPH)] and compared them with those presenting with LBBB or with other electrocardiographic (ECG) patterns. The aim was to describe angiographic patterns and primary angioplasty use in AMI patients with RBBB. Methods and results A cohort of 6742 patients with AMI admitted to eight participating hospitals was analysed. Baseline clinical characteristics, ECG patterns, coronary angiographic, and echocardiographic data were correlated with the reperfusion therapies used and with in-hospital outcomes. Right bundle branch block was present in 6.3% of AMI patients: 2.8% had RBBB alone, 3.2% had RBBB + LAH, and 0.3% had RBBB + LPH. TIMI flow 0 in the infarct-related artery was present in 51.7% of RBBB patients vs. 39.4% of LBBB patients (P = 0.023). Primary percutaneous coronary intervention (PCI) was performed in 80.1% of RBBB patients vs. 68.3% of LBBB patients (Pblocks had the highest (LBBB 15.8% and RBBB 15.4%) incidence of cardiogenic shock from all ECG subgroups. Percutaneous coronary intervention was done more frequently (84.8%) in patients with new or presumably new RBBB when compared with other patients with blocks (old RBBB 66.0%, old LBBB 62.3%, new or presumably new LBBB 73.0%). In-hospital mortality was highest (18.8%) among patients presenting with new or presumably new RBBB, followed by new or presumably new LBBB (13.2%), old LBBB (10.1%), and old RBBB (6.4%). Among 35 patients with acute left main coronary artery occlusion, 26% presented with RBBB (mostly with LAH) on the admission ECG. Conclusion Acute myocardial infarction with RBBB is frequently caused by the

  2. Transcatheter Heart Valve Selection and Permanent Pacemaker Implantation in Patients With Pre-Existent Right Bundle Branch Block.

    Science.gov (United States)

    van Gils, Lennart; Tchetche, Didier; Lhermusier, Thibault; Abawi, Masieh; Dumonteil, Nicolas; Rodriguez Olivares, Ramón; Molina-Martin de Nicolas, Javier; Stella, Pieter R; Carrié, Didier; De Jaegere, Peter P; Van Mieghem, Nicolas M

    2017-03-03

    Right bundle branch block is an established predictor for new conduction disturbances and need for a permanent pacemaker (PPM) after transcatheter aortic valve replacement. The aim of the study was to evaluate the absolute rates of transcatheter aortic valve replacement related PPM implantations in patients with pre-existent right bundle branch block and categorize for different transcatheter heart valves. We pooled data on 306 transcatheter aortic valve replacement patients from 4 high-volume centers in Europe and selected those with right bundle branch block at baseline without a previously implanted PPM. Logistic regression was used to evaluate whether PPM rate differed among transcatheter heart valves after adjustment for confounders. Mean age was 83±7 years and 63% were male. Median Society of Thoracic Surgeons score was 6.3 (interquartile range, 4.1-10.2). The following transcatheter valve designs were used: Medtronic CoreValve (n=130; Medtronic, Minneapolis, MN); Edwards Sapien XT (ES-XT; n=124) and Edwards Sapien 3 (ES-3; n=32; Edwards Lifesciences, Irvine, CA); and Boston Scientific Lotus (n=20; Boston Scientific Corporation, Marlborough, MA). Overall permanent pacemaker implantation rate post-transcatheter aortic valve replacement was 41%, and per valve design: 75% with Lotus, 46% with CoreValve, 32% with ES-XT, and 34% with ES-3. The indication for PPM implantation was total atrioventricular block in 98% of the cases. Lotus was associated with a higher PPM rate than all other valves. PPM rate did not differ between ES-XT and ES-3. Ventricular paced rhythm at 30-day and 1-year follow-up was present in 81% at 89%, respectively. Right bundle branch block at baseline is associated with a high incidence of PPM implantation for all transcatheter heart valves. PPM rate was highest for Lotus and lowest for ES-XT and ES-3. Pacemaker dependency remained high during follow-up. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by

  3. Exercise Induced Left Bundle Branch Block Treated with Cardiac Rehabilitation: A Case Report and a Review of the Literature

    Directory of Open Access Journals (Sweden)

    Nathan S. Anderson

    2014-01-01

    Full Text Available Exercise induced bundle branch block is a rare observation in exercise testing, accounting for 0.5 percent of exercise tests. The best treatment of this condition and its association with coronary disease remain unclear. We describe a case associated with normal coronary arteries which was successfully treated with exercise training. While this treatment has been used previously, our case has a longer followup than previously reported and demonstrates that the treatment is not durable in the absence of continued exercise.

  4. Left ventricular performance during triggered left ventricular pacing in patients with cardiac resynchronization therapy and left bundle branch block

    DEFF Research Database (Denmark)

    Witt, Christoffer Tobias; Kronborg, Mads Brix; Nohr, Ellen Aagaard

    2016-01-01

    complex >150 ms, QRS complex narrowing under CRT, and sinus rhythm were included ≥3 months after CRT implantation. Echocardiographic assessment of left ventricular ejection fraction (LVEF), global peak systolic longitudinal strain (GLS), and contraction pattern by 2D strain was performed during intrinsic......PURPOSE: To assess the acute effect of triggered left ventricular pacing (tLVp) on left ventricular performance and contraction pattern in patients with heart failure, left bundle branch block (LBBB), and cardiac resynchronization therapy (CRT). METHODS: Twenty-three patients with pre-implant QRS...

  5. Left ventricular regional contraction abnormalities by echocardiographic speckle tracking in combined right bundle branch with left anterior fascicular block compared to left bundle branch block

    DEFF Research Database (Denmark)

    Leeters, Irene P M; Davis, Ashlee; Zusterzeel, Robbert

    2016-01-01

    patterns compared to other groups (LBBB: p=0.042, no-block: p=0.012). In addition, RBBB+LAFB patients had more scar than LBBB patients (9.9% vs 3.4%, p=0.041), and the average amount of scar in each wall was also higher in RBBB+LAFB (... to LBBB. Factors that might alter strain patterns in RBBB+LAFB, including the detailed presence or absence of LV scar and coexisting block of the central fascicle, should be assessed in future studies....

  6. Factors determining the magnitude of the pre-ejection leftward septal motion in left bundle branch block.

    Science.gov (United States)

    Remme, Espen W; Niederer, Steven; Gjesdal, Ola; Russell, Kristoffer; Hyde, Eoin R; Smith, Nicolas; Smiseth, Otto A

    2016-12-01

    An abnormal large leftward septal motion prior to ejection is frequently observed in left bundle branch block (LBBB) patients. This motion has been proposed as a predictor of response to cardiac resynchronization therapy (CRT). Our goal was to investigate factors that influence its magnitude. Left (LVP) and right ventricular (RVP) pressures and left ventricular (LV) volume were measured in eight canines. After induction of LBBB, LVP and, hence, the transmural septal pressure (P LV-RV = LVP-RVP) increased more slowly (P bundle branch block lowers afterload against pre-ejection septal contraction, expressed as slowed rise of P LV-RV , which is a main cause and determinant of the magnitude of leftward septal motion. The motion may be small or absent due to septal infarct, impaired global or RV contractility or RV volume overload, which should be kept in mind if this motion is to be used in evaluation of CRT response. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

  7. Cardiac resynchronization therapy for heart failure induced by left bundle branch block after transcatheter closure of ventricular septal defect

    Science.gov (United States)

    Du, Rong-Zeng; Qian, Jun; Wu, Jun; Liang, Yi; Chen, Guang-Hua; Sun, Tao; Zhou, Ye; Zhao, Yang; Yan, Jin-Chuan

    2014-01-01

    A 54-year-old female patient with congenital heart disease had a persistent complete left bundle branch block three months after closure by an Amplatzer ventricular septal defect occluder. Nine months later, the patient suffered from chest distress, palpitation, and sweating at daily activities, and her 6-min walk distance decreased significantly (155 m). Her echocardiography showed increased left ventricular end-diastolic diameter with left ventricular ejection fraction of 37%. Her symptoms reduced significantly one week after received cardiac resynchronization therapy. She had no symptoms at daily activities, and her echo showed left ventricular ejection fraction of 46% and 53%. Moreover, left ventricular end-diastolic diameter decreased 6 and 10 months after cardiac resynchronization therapy, and 6-min walk distance remarkably increased. This case demonstrated that persistent complete left bundle branch block for nine months after transcatheter closure with ventricular septal defect Amplatzer occluder could lead to left ventricular enlargement and a significant decrease in left ventricular systolic function. Cardiac resynchronization therapy decreased left ventricular end-diastolic diameter and increased left ventricular ejection fraction, thereby improving the patient's heart functions. PMID:25593586

  8. Usefulness of His Bundle Pacing to Achieve Electrical Resynchronization in Patients With Complete Left Bundle Branch Block and the Relation Between Native QRS Axis, Duration, and Normalization.

    Science.gov (United States)

    Teng, Alexandra E; Lustgarten, Daniel L; Vijayaraman, Pugazhendhi; Tung, Roderick; Shivkumar, Kalyanam; Wagner, Galen S; Ajijola, Olujimi A

    2016-08-15

    His Bundle pacing (HBP) restores electrical synchronization in left bundle branch block (LBBB); however, the underlying mechanisms are poorly understood. We examined the relation between native QRS axis in LBBB, a potential indicator of the site of block, and QRS normalization in patients with LBBB. Data from patients (n = 41) undergoing HBP at 3 sites were studied (68 ± 13 years, 13 women). Study criteria included strictly defined complete LBBB and successful implantation of a permanent HBP lead. Preprocedure and postprocedure electrocardiograms were reviewed independently by 2 blinded readers. QRS axis and duration were measured to the nearest 10° and 10 ms, respectively. QRS narrowing or normalization was the primary end point. Of 29 patients meeting study criteria, 9 had frontal plane QRS axes between -60° and -80°, 10 from -40° to 0°, and 10 from +1° to +90°. QRS narrowing occurred in 24 patients (83%, 44 ± 34 ms, p block causes most cases of LBBB, or that additional mechanisms underlie HBP efficacy. Further studies are needed to better understand how to predict those patients in whom HBP will normalize LBBB. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Tachycardia-dependent bilateral bundle branch block in ischemic heart disease with systolic dysfunction: case report and review of prognostic implications.

    Science.gov (United States)

    Ferrando-Castagnetto, Federico; Vidal, Alejandro; Ricca-Mallada, Roberto; Nogara, Romina; Marichal, Pablo; Martínez, Fabián

    2015-10-16

    A proper characterization of frequency-dependent bundle branch blocks can provide useful prognostic information in some clinical situations. Often, this physiological event may be due to an extensive damage of infrahisian system, which poses a high risk of developing advanced atrioventricular block requiring pacemaker implantation. We describe the case of a 62 year-old man with chronic ischemic heart disease who exhibited alternating tachycardia-dependent bundle branch block during stress test. We discuss the main prognostic implications of this unusual event in the context of systolic dysfunction.

  10. Left ventricular regional contraction abnormalities by echocardiographic speckle tracking in combined right bundle branch with left anterior fascicular block compared to left bundle branch block.

    Science.gov (United States)

    Leeters, Irene P M; Davis, Ashlee; Zusterzeel, Robbert; Atwater, Brett; Risum, Niels; Søgaard, Peter; Klem, Igor; Nijveldt, Robin; Wagner, Galen S; Gorgels, Anton P M; Kisslo, Joseph

    2016-01-01

    In contrast to LBBB patients less is known about patients with RBBB+LAFB regarding LV contractile abnormalities and the potential role of CRT. This study investigated whether patients with RBBB+LAFB morphology have echocardiographic mechanical strain abnormalities between the inferior and anterior LV walls, similar to abnormalities between septal and lateral walls in LBBB. Ten healthy volunteers with no-BBB, 28 LBBB and 28 RBBB+LAFB heart failure patients were included in this retrospective study. Two-dimensional regional-strains were obtained by speckle-tracking. Scar was assessed by CMR. Response on echo was defined as normal, classical, borderline or other pattern. The number of classical patterns in LBBB was significantly higher than in RBBB+LAFB and no-BBB groups (pblock: p=0.012). In addition, RBBB+LAFB patients had more scar than LBBB patients (9.9% vs 3.4%, p=0.041), and the average amount of scar in each wall was also higher in RBBB+LAFB (block of the central fascicle, should be assessed in future studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Right ventricular electrical and mechanical synchronization by properly timed septal pacing in a patient with right bundle branch block and first degree AV block--a case report.

    Science.gov (United States)

    Siliste, Calin; Suran, Maria-Claudia-Berenice; Margulescu, Andrei-Dumitru; Vinereanu, Dragos

    2015-03-01

    We present a case of near-normalization of the QRS by septal pacing in a patient with dual-chamber pacemaker and underlying complete right bundle branch block and first degree atrioventricular block. The right ventricular mechanical synchronization suggested by the ECG was validated as such by strain echo. To the best of our knowledge, this is the first time it has been shown that the narrowing of the QRS corresponds to mechanical synchronization in a case of this seldom-recognized phenomenon. © 2014 Wiley Periodicals, Inc.

  12. Usefulness of His Bundle Pacing to Achieve Electrical Resynchronization in Patients with Complete Left Bundle Branch Block and the Relation Between Native QRS Axis, Duration, and Normalization

    Science.gov (United States)

    Teng, Alexandra E.; Lustgarten, Daniel L.; Vijayaraman, Pugazhendhi; Tung, Roderick; Shivkumar, Kalyanam; Wagner, Galen S.; Ajijola, Olujimi A.

    2016-01-01

    His Bundle pacing (HBP) restores electrical synchronization in left bundle branch block (LBBB), however, the underlying mechanisms are poorly understood. We examined the relationship between native QRS axis in LBBB, a potential indicator of the site of block, and QRS normalization in patients with LBBB. Data from patients (n=41) undergoing HBP at three sites were studied (68±13 years, 13 females). Study criteria included strictly defined complete LBBB, and successful implantation of a permanent HBP lead. Pre- and post-procedure electrocardiograms were reviewed independently by two blinded readers. QRS axis and duration were measured to the nearest 10° and 10ms, respectively. QRS narrowing or normalization was the primary endpoint. Of 29 patients meeting study criteria, 9 had frontal plane QRS axes between −60° and −80°, 10 from −40° to 0°, and 10 from +1° to +90°. QRS narrowing occurred in 24 patients (83%, 44±34ms, pblock causes most cases of LBBB, or that additional mechanisms underlie HBP efficacy. Further studies are needed to better understand how to predict those patients in whom HBP will normalize LBBB. PMID:27344272

  13. Development of a swine model of left bundle branch block for experimental studies of cardiac resynchronization therapy.

    Science.gov (United States)

    Rigol, Montserrat; Solanes, Núria; Fernandez-Armenta, Juan; Silva, Etelvino; Doltra, Adelina; Duchateau, Nicolas; Barcelo, Aina; Gabrielli, Luigi; Bijnens, Bart; Berruezo, Antonio; Brugada, Josep; Sitges, Marta

    2013-08-01

    Animal models that mimic human electrical and mechanical dyssynchrony often associated with chronic heart failure would provide an essential tool to investigate factors influencing response to cardiac resynchronization therapy. A standardized closed-chest porcine model of left bundle branch block (LBBB) was developed using 16 pigs. Radiofrequency applications were performed to induce LBBB, which was confirmed by QRS widening, a surface electrocardiogram pattern concordant with LBBB, and a prolonged activation time from endocardial. Echocardiography confirmed abnormal motion of the septum, which was not present at the baseline echocardiogram. High susceptibility of pigs to ventricular fibrillation during the endocardial ablation was overcome by applying high-rate pacing during radiofrequency applications. This is the first study to devise a closed-chest porcine model of LBBB that closely reproduces abnormalities found in patients with electrical and mechanical cardiac dyssynchrony, and provides a useful tool to investigate the basic mechanisms underlying cardiac resynchronization therapy benefits in heart failure.

  14. Exercise-induced left bundle branch block and subsequent mechanical left ventricular dyssynchrony -resolved with pharmacological therapy

    Science.gov (United States)

    2011-01-01

    A 53-year-old man with depressed ejection fraction (EF) of 35% and QRS width of 88 ms at rest was admitted to our institution with a complaint of exertional chest discomfort and dyspnea. During treadmill exercise, left bundle-branch block (LBBB) with a QRS width of 152 ms occurred at a heart rate of 100 bpm. During LBBB, the patient showed significant mechanical dyssynchrony as evidenced by a two-dimensional speckle tracking radial strain of 260 ms (≥130 ms), defined as the time difference between anterior-septum and posterior wall. Five-month after carvedilol and candesartan administration, EF had improved to 49% and LBBB did not occur until a heart rate of 126 bpm was attained during treadmill exercise. It appears that pharmacological therapy may be useful for patients with heart failure and exercise-induced LBBB. PMID:21294925

  15. Exercise-induced left bundle branch block and subsequent mechanical left ventricular dyssynchrony -resolved with pharmacological therapy

    Directory of Open Access Journals (Sweden)

    Tatsumi Kazuhiro

    2011-02-01

    Full Text Available Abstract A 53-year-old man with depressed ejection fraction (EF of 35% and QRS width of 88 ms at rest was admitted to our institution with a complaint of exertional chest discomfort and dyspnea. During treadmill exercise, left bundle-branch block (LBBB with a QRS width of 152 ms occurred at a heart rate of 100 bpm. During LBBB, the patient showed significant mechanical dyssynchrony as evidenced by a two-dimensional speckle tracking radial strain of 260 ms (≥130 ms, defined as the time difference between anterior-septum and posterior wall. Five-month after carvedilol and candesartan administration, EF had improved to 49% and LBBB did not occur until a heart rate of 126 bpm was attained during treadmill exercise. It appears that pharmacological therapy may be useful for patients with heart failure and exercise-induced LBBB.

  16. Mechanical analysis of congestive heart failure caused by bundle branch block based on an electromechanical canine heart model

    Science.gov (United States)

    Dou, Jianhong; Xia, Ling; Zhang, Yu; Shou, Guofa; Wei, Qing; Liu, Feng; Crozier, Stuart

    2009-01-01

    Asynchronous electrical activation, induced by bundle branch block (BBB), can cause reduced ventricular function. However, the effects of BBB on the mechanical function of heart are difficult to assess experimentally. Many heart models have been developed to investigate cardiac properties during BBB but have mainly focused on the electrophysiological properties. To date, the mechanical function of BBB has not been well investigated. Based on a three-dimensional electromechanical canine heart model, the mechanical properties of complete left and right bundle branch block (LBBB and RBBB) were simulated. The anatomical model as well as the fiber orientations of a dog heart was reconstructed from magnetic resonance imaging (MRI) and diffusion tensor MRI (DT-MRI). Using the solutions of reaction-diffusion equations and with a strategy of parallel computation, the asynchronous excitation propagation and intraventricular conduction in BBB was simulated. The mechanics of myocardial tissues were computed with time-, sarcomere length-dependent uniaxial active stress initiated at the time of depolarization. The quantification of mechanical intra- and interventricular asynchrony of BBB was then investigated using the finite-element method with an eight-node isoparametric element. The simulation results show that (1) there exists inter- and intraventricular systolic dyssynchrony during BBB; (2) RBBB may have more mechanical synchrony and better systolic function of the left ventricle (LV) than LBBB; (3) the ventricles always move toward the early-activated ventricle; and (4) the septum experiences higher stress than left and right ventricular free walls in BBB. The simulation results validate clinical and experimental recordings of heart deformation and provide regional quantitative estimates of ventricular wall strain and stress. The present work suggests that an electromechanical heart model, incorporating real geometry and fiber orientations, may be helpful for better

  17. Diagnosis and outcome in a prehospital cohort of patients with bundle branch block and suspected acute myocardial infarction.

    Science.gov (United States)

    Sørensen, Jacob Thorsted; Stengaard, Carsten; Sørensen, Christina Ankjær; Thygesen, Kristian; Bøtker, Hans Erik; Thuesen, Leif; Terkelsen, Christian Juhl

    2013-06-01

    Immediate revascularization is beneficial in patients with presumed new-onset bundle branch block myocardial infarction (BBBMI). In the prehospital setting, it is a challenge to diagnose new-onset BBBMI and triage accordingly. ECG, final diagnosis, and mortality were assessed in a prehospital cohort of 4905 consecutive patients with suspected acute myocardial infarction (AMI). Bundle branch block (BBB) was defined as QRS duration ≥120 ms caused by delayed intraventricular conduction. Mortality and angiography data were obtained from the Central Office of Civil Registration and the Western Denmark Heart Registry. Definite diagnosis of AMI and the onset of BBB were determined by expert consensus. Patients were divided into four groups: with or without AMI and with or without BBB. Mortality was evaluated by Kaplan-Meier plots and compared using log-rank statistics. AMI was diagnosed in 954 patients, of whom 118 had BBB. In 3951 patients without AMI, 436 had BBB. Patients with BBBMI were less often revascularized than patients with AMI without BBB (24 vs. 54%, p<0.001). BBBMI was categorized as new onset in 43 patients of whom two were triaged for acute angioplasty. One-year mortality was 47.2, 17.5, 20.8, and 8.6% (log-rank <0.001) in patients with BBBMI, patients with AMI without BBB, patients with BBB without AMI, and patients without AMI or BBB, respectively. Patients with BBBMI have a high mortality. Less than 25% undergo revascularization and only very few patients with new-onset BBBMI are transferred for urgent revascularization. Focus on improving triage and prehospital identification of high-risk patients with BBB and chest pain could improve outcome.

  18. Diagnosis and outcome in a prehospital cohort of patients with bundle branch block and suspected acute myocardial infarction

    Science.gov (United States)

    Stengaard, Carsten; Sørensen, Christina Ankjær; Thygesen, Kristian; Bøtker, Hans Erik; Thuesen, Leif; Terkelsen, Christian Juhl

    2013-01-01

    Background: Immediate revascularization is beneficial in patients with presumed new-onset bundle branch block myocardial infarction (BBBMI). In the prehospital setting, it is a challenge to diagnose new-onset BBBMI and triage accordingly. Methods: ECG, final diagnosis, and mortality were assessed in a prehospital cohort of 4905 consecutive patients with suspected acute myocardial infarction (AMI). Bundle branch block (BBB) was defined as QRS duration ≥120 ms caused by delayed intraventricular conduction. Mortality and angiography data were obtained from the Central Office of Civil Registration and the Western Denmark Heart Registry. Definite diagnosis of AMI and the onset of BBB were determined by expert consensus. Patients were divided into four groups: with or without AMI and with or without BBB. Mortality was evaluated by Kaplan–Meier plots and compared using log-rank statistics. Results: AMI was diagnosed in 954 patients, of whom 118 had BBB. In 3951 patients without AMI, 436 had BBB. Patients with BBBMI were less often revascularized than patients with AMI without BBB (24 vs. 54%, p<0.001). BBBMI was categorized as new onset in 43 patients of whom two were triaged for acute angioplasty. One-year mortality was 47.2, 17.5, 20.8, and 8.6% (log-rank <0.001) in patients with BBBMI, patients with AMI without BBB, patients with BBB without AMI, and patients without AMI or BBB, respectively. Conclusions: Patients with BBBMI have a high mortality. Less than 25% undergo revascularization and only very few patients with new-onset BBBMI are transferred for urgent revascularization. Focus on improving triage and prehospital identification of high-risk patients with BBB and chest pain could improve outcome. PMID:24222828

  19. Utility of incomplete right bundle branch block as an isolated ECG finding in children undergoing initial cardiac evaluation.

    Science.gov (United States)

    Meziab, Omar; Abrams, Dominic J; Alexander, Mark E; Bevilacqua, Laura; Bezzerides, Vassilios; Mah, Doug Y; Walsh, Edward P; Triedman, John K

    2018-02-12

    This study evaluates the ability of experienced pediatric electrophysiologists (EPs) to reliably classify incomplete right bundle branch block (IRBBB) and assesses its clinical utility as an isolated ECG finding in a group of healthy outpatient children without prior cardiac evaluation. We performed a retrospective analysis of all electrocardiographic and echocardiographic records at Boston Children's Hospital between January 1, 2005, and December 31, 2014. Echocardiographic diagnoses were identified if registered between the date of the index electrocardiogram and the ensuing year. A selected subset of 473 ECGs was subsequently reanalyzed in a blinded manner by six pediatric EPs to determine the consistency with which the finding of IRBBB could be assigned. Of the 331 278 ECGs registered in the BCH database, 32 127 (9.7%) met inclusion criteria and were analyzed for the prevalence of isolated right bundle conduction disturbance findings. The mean age was 12.1 ± 4.0 years, and the population was 49% male. Of the 32 127 ECGs, 72.5% were coded normal, 3.0% were coded IRBBB, and 0.5% were coded complete right bundle branch block (CRBBB). A total of 7.3% of patients coded as normal had an ensuing echocardiogram, compared to 12.5% coded IRBBB. Echo findings were recorded in 0.1% of normal and 0.2% of IRBBB. Patients with ASD-secundum type were no more likely to have isolated IRBBB on previous ECG than the general population (2.5% vs 3.0%). Analysis of inter-reader variability in ECG findings and conduction disturbance identification was high (range of IRBBB prevalence 1-20% among readers). Reinterpretation of ECGs using explicit diagnostic criteria did not demonstrate consistent discrimination of IRBBB and Normal ECGs. IRBBB is not uncommon in a healthy school age population and is observed to have high inter-reader variability. It was associated with increased use of echocardiographic exam but was not associated with increased rate of echocardiographic findings

  20. Comparative Long-Term Outcomes after Cardiac Resynchronization Therapy in Right Ventricular Paced Patients versus Native Wide Left Bundle Branch Block Patients

    DEFF Research Database (Denmark)

    Tayal, Bhupendar; Gorcsan, John; Delgado-Montero, Antonia

    2016-01-01

    to compare the long-term survival after CRT in patients upgraded from RVP with that in patients with left bundle branch block (LBBB) with QRS duration ≥ 150 ms and to compare the mechanical properties associated with CRT response in these groups. METHODS: Overall, 135 patients with implanted CRT from...

  1. Identification of Typical Left Bundle Branch Block Contraction by Strain Echocardiography Is Additive to Electrocardiography in Prediction of Long-Term Outcome After Cardiac Resynchronization Therapy

    DEFF Research Database (Denmark)

    Risum, Niels; Tayal, Bhupendar; Hansen, Thomas F

    2015-01-01

    BACKGROUND: Current guidelines suggest that patients with left bundle branch block (LBBB) be treated with cardiac resynchronization therapy (CRT); however, one-third do not have a significant activation delay, which can result in nonresponse. By identifying characteristic opposing wall contractio...

  2. Mortality risk associated with bundle branch blocks and related repolarization abnormalities (from the Women's Health Initiative [WHI]).

    Science.gov (United States)

    Zhang, Zhu-ming; Rautaharju, Pentti M; Soliman, Elsayed Z; Manson, Joann E; Cain, Michael E; Martin, Lisa W; Bavry, Anthony A; Mehta, Laxmi; Vitolins, Mara; Prineas, Ronald J

    2012-11-15

    Electrocardiographic bundle branch block (BBB) has higher cardiac and all-cause death. However, reports on the association between BBBs and mortality in the general populations are conflicting. The aim of this study was to evaluate the risk for coronary heart disease (CHD) and all-cause death associated with left BBB (LBBB) and right BBB (RBBB) during 14 years of follow-up in 66,450 participants from the Women's Health Initiative (WHI) study. Cox proportional-hazards regression was performed for mortality risk in Women with LBBB (n = 714) and those with RBBB (n = 832). In risk models adjusted for demographic and clinical risk factors in women with cardiovascular disease (CVD), hazard ratios for CHD death were 2.92 (95% confidence interval 2.08 to 4.08, p women, only LBBB was a significant predictor of CHD death (fully adjusted hazard ratio 2.17, 95% confidence interval 1.37 to 3.43, p women with LBBB was an independent predictor of CHD death, with a more than fivefold increase in risk. None of the repolarization variables were independent predictors in women with RBBB. In conclusion, prevalent LBBB in CVD-free women and LBBB and RBBB in women with CVD were significant predictors of CHD death. In women with LBBB, ST J-point depression in lead aVL was a strong independent predictor of CHD death. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Reservations about the Selvester QRS score in left bundle branch block - Experience in patients with transcatheter aortic valve implantation.

    Science.gov (United States)

    Poels, Thomas T; Kats, Suzanne; Veenstra, Leo; van Ommen, Vincent; Maessen, Jos G; Prinzen, Frits W

    The Selvester QRS score (S-score) estimates myocardial scar using electrocardiographic criteria. We evaluated the S-score for left bundle branch block (LBBB). Studied were 36 patients who developed persistent LBBB upon transcatheter aortic valve implantation (TAVI, TAVI-LBBB group) and 36 matched patients with persistent narrow QRS (TAVI-nQRS group). Electrocardiograms were recorded before and briefly after TAVI and during ~6months follow-up. S-score was calculated using criteria for hypertrophic (in absence of LBBB) or LBBB hearts. In TAVI-LBBB patients correlation between S-scores pre-TAVI and post-TAVI was absent (R 2 =0.023). High S-scores post-TAVI occurred in patients with low pre-TAVI scores. Pre-post TAVI scores correlated weakly in TAVI-nQRS (R 2 =0.182), indicating a possible influence of ventricular unloading by TAVI. In both groups S-scores at post-TAVI and follow-up compared reasonably (R 2 =0.389 and R 2 =0.386), indicating reproducibility in more stable conditions. This study indicates that the use of the LBBB S-score criteria overestimates scar size and that caution is recommended in the use of the score in patients with LBBB. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  4. Cardiac MRI assessment of right ventricular function: impact of right bundle branch block on the evaluation of cardiac performance parameters

    Energy Technology Data Exchange (ETDEWEB)

    Marterer, Robert; Tschauner, Sebastian; Sorantin, Erich [Medical University of Graz, Division of Pediatric Radiology, Department of Radiology, Graz (Austria); Zeng, Hongchun [First Affiliated Hospital of Xinjiang Medical University, Department of Ultrasonography, Urumqi (China); Koestenberger, Martin [Medical University of Graz, Division of Pediatric Cardiology, Department of Pediatrics and Adolescent Medicine, Graz (Austria)

    2015-12-15

    Right ventricular (RV) function represents a prognostic marker in patients with corrected congenital heart disease. In up to 80 % of these patients, right branch bundle block (RBBB) exists and leads to asynchronous ventricular contraction. The aim of this retrospective study was to evaluate the change of RV performance parameters considering delayed RV end-systolic contraction. RV volumes of 33 patients were assessed twice: 1) not taking account of RBBB (group I), and 2) considering RBBB (group II). According to the RV ejection fraction (EF) for both groups, RV function was classified in different categories (>50 % = normal, 40-50 % = mildly-, 30-40 % = moderately-, <30 % = severely-reduced). The mean time difference between maximal systolic contraction of the septum and RV free wall was 90.7 ms ± 42.6. Consequently, RV end-systolic volume was significantly decreased in group II (p < 0.001). Accordingly, RV stroke volume and RV EF were significantly higher in group II (p < 0.001). There was also a significant change in the assessment of RV function (p < 0.02). RBBB induced delayed RV contraction can be detected at CMR. Ignoring the RV physiology in RBBB patients leads to a statistically significant underscoring of RV performance parameters. (orig.)

  5. Clinical Characteristics, Management, and Outcomes of Acute Coronary Syndrome in Patients With Right Bundle Branch Block on Presentation.

    Science.gov (United States)

    Chan, William K; Goodman, Shaun G; Brieger, David; Fox, Keith A A; Gale, Chris P; Chew, Derek P; Udell, Jacob A; Lopez-Sendon, Jose; Huynh, Thao; Yan, Raymond T; Singh, Sheldon M; Yan, Andrew T

    2016-03-01

    We examined the relations between right bundle branch block (RBBB) and clinical characteristics, management, and outcomes among a broad spectrum of patients with acute coronary syndrome (ACS). Admission electrocardiograms of patients enrolled in the Global Registry of Acute Coronary Events (GRACE) electrocardiogram substudy and the Canadian ACS Registry I were analyzed independently at a blinded core laboratory. We performed multivariable logistic regression analysis to assess the independent prognostic significance of admission RBBB on in-hospital and 6-month mortality. Of 11,830 eligible patients with ACS (mean age 65; 66% non-ST-elevation ACS), 5% had RBBB. RBBB on admission was associated with older age, male sex, more cardiovascular risk factors, worse Killip class, and higher GRACE risk score (all p 0.50). In conclusion, across a spectrum of ACS, RBBB was associated with preexisting cardiovascular disease, high-risk clinical features, fewer cardiac interventions, and worse unadjusted outcomes. After adjusting for components of the GRACE risk score, RBBB was a significant independent predictor of early mortality. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Prognostic Implication of the QRS Axis and its Association with Myocardial Scarring in Patients with Left Bundle Branch Block.

    Science.gov (United States)

    Park, Chan Soon; Cha, Myung-Jin; Choi, Eue-Keun; Oh, Seil

    2017-03-01

    Left bundle branch block (LBBB) with left axis deviation (LAD) has a worse prognosis than LBBB with a normal axis, and myocardial dysfunction has been suggested as a cause of left axis deviation. This study investigated the prognostic significance of the QRS axis in patients with LBBB and analyzed its relationship with the amount of myocardial scarring. A total of 829 patients were diagnosed with LBBB at Seoul National University Hospital from October 2004 to June 2014. Of these, 314 who were asymptomatic and had no previous history of cardiac disease were included in the present study. Myocardial scarring was calculated using the Selvester QRS scoring system, and LAD was defined as a QRS axis between -180° and -30°. Of the total patients, 91 (29%) had LAD, and patients were followed for a median of 30 months. During follow-up, two patients were hospitalized for de novo heart failure, four had pacemaker implants, and 10 died. There was a significant inverse correlation between myocardial scar score and the QRS axis (r=-0.356, paxis (5.5% vs. 1.3%, log-rank p=0.010); the prognostic value was attenuated in multivariable analysis (hazard ratio 4.117; 95% confidence interval 0.955-17.743; p=0.058). Concomitant LAD is an indicator of poor prognosis for patients with LBBB and may be associated with greater myocardial scarring.

  7. Left bundle branch block with intermittent QRS axis switching: observation of a hypertensive patient for 18 years.

    Science.gov (United States)

    Takato, Tetsuya; Yamada, Namie; Fujii, Jun; Mashima, Saburo; Ashida, Terunao

    2009-09-01

    A 64-year-old man who had been prescribed antihypertensive drugs since 1971 attended our clinic in 1988 with hypertension and electrocardiographic abnormalities. An electrocardiogram revealed left axis deviation (LAD) in 1988 and slightly prolonged PQ intervals in 1993. Complete left bundle branch block (CLBBB) with LAD developed in May 1995. The wide QRS of the CLBBB had never returned to the normal narrow QRS and had intermittently alternated between LAD and normal axis. The PQ intervals were longer when the QRS axis showed LAD compared to that with normal QRS axis. The QRS complexes in leads V1-V3 revealed an R wave at LAD and a QS pattern at normal axis. During a deep breathing test, the QRS axis switched from normal axis to LAD at the end of forced expiration and also switched from normal axis to LAD within a few minutes after the exercise test. These results suggest that the shift of the QRS axis might be related to the tone of the autonomic nervous system.

  8. Atrial fibrillation with left bundle branch block and intermittent right axis deviation during acute myocardial infarction.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Di Bella, Gianluca

    2008-06-23

    Rarely the ECG shows an LBBB with changing QRS morphology and changing axis deviation. The intermittent positive aspect of the neglected lead aVR indicates an intermittent right axis deviation in the presence of complete LBBB. An additional left posterior fascicular block accompanying predivisional LBBB is the possible explanation. We describe the case of a 78-year-old Italian woman admitted to the Cardiology Unit with acute myocardial infarction and permanent atrial fibrillation. Electrocardiographic changes were observed. The ECG showed atrial fibrillation and LBBB with intermittent left axis deviation or atrial fibrillation and LBBB with intermittent right axis deviation.

  9. Comparison of incidence and predictors of left bundle branch block after transcatheter aortic valve implantation using the CoreValve versus the Edwards valve.

    Science.gov (United States)

    Franzoni, Irene; Latib, Azeem; Maisano, Francesco; Costopoulos, Charis; Testa, Luca; Figini, Filippo; Giannini, Francesco; Basavarajaiah, Sandeep; Mussardo, Marco; Slavich, Massimo; Taramasso, Maurizio; Cioni, Micaela; Longoni, Matteo; Ferrarello, Santo; Radinovic, Andrea; Sala, Simone; Ajello, Silvia; Sticchi, Alessandro; Giglio, Manuela; Agricola, Eustachio; Chieffo, Alaide; Montorfano, Matteo; Alfieri, Ottavio; Colombo, Antonio

    2013-08-15

    Conduction disorders and permanent pacemaker implantation are common complications in patients who undergo transcatheter aortic valve implantation (TAVI). The aim of this study was to assess the incidence and clinical significance of new bundle branch block in patients who underwent TAVI with the Medtronic CoreValve Revalving System (MCRS) or the Edwards SAPIEN valve (ESV). Data from 238 patients with no previous pacemaker implantation, left bundle branch block (LBBB) or right bundle branch block at baseline electrocardiography who underwent TAVI with either MCRS (n = 87) or ESV (n = 151) bioprostheses from 2007 to 2011 were analyzed. New-onset LBBB occurred in 26.5% patients (n = 63): 13.5% with the ESV (n = 20) and 50.0% with the MCRS (n = 43) (p = 0.001). Permanent pacemaker implantation was required in 12.7% of patients (n = 8) because of complete atrioventricular block (ESV n = 2, MCRS n = 4), LBBB and first degree atrioventricular block (MCRS n = 1) and new-onset LBBB associated with sinus bradycardia (MCRS n = 1). At discharge, LBBB persisted in 8.6% of ESV patients (n = 13) and 32.2% of MCRS patients (n = 28) (p = 0.001). On multivariate analysis, the only predictor of LBBB was MCRS use (odds ratio 7.2, 95% confidence interval 2.9 to 17.4, p bundle branch block was documented in 4.6% of patients (n = 11), with no statistically significant differences between the ESV and MCRS. In conclusion, new-onset LBBB is a frequent intraventricular conduction disturbance after TAVI with a higher incidence with the MCRS compared with the ESV. LBBB persists in most patients, but in this cohort, it was not a predictor of overall or cardiovascular mortality or permanent pacemaker implantation. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Predictive factor and clinical consequence of left bundle-branch block after a transcatheter aortic valve implantation.

    Science.gov (United States)

    Nishiyama, Takahiko; Tanosaki, Sho; Tanaka, Makoto; Yanagisawa, Ryo; Yashima, Fumiaki; Kimura, Takehiro; Arai, Takahide; Tsuruta, Hikaru; Murata, Mitsushige; Aizawa, Yoshiyasu; Kohno, Takashi; Maekawa, Yuichiro; Hayashida, Kentaro; Takatsuki, Seiji; Fukuda, Keiichi

    2017-01-15

    Atrioventricular conduction disturbances can develop after transcatherter aortic valve implantations (TAVIs) with balloon-expandable valves because the conduction system exists adjacent to the aortic valve. However, the clinical consequence of patients with new onset conduction disturbances is not clear. This study aimed to assess the incidence and progress of new-onset conduction disturbances following TAVIs and the cardiac function evaluated by echocardiography. This study consisted of 90 consecutive patients that underwent TAVIs with Edwards SAPIEN XT valves in a single center. Atrioventricular conduction system disturbances were assessed by electrocardiography and echocardiography up to 6months post TAVI. Twenty patients (22%) developed new onset complete left bundle branch block (CLBBB) or received pacemaker implantations (PMIs) during the follow-up. At 6months after the procedure, 4 patients underwent PMIs for complete AV block (CAVB), and 4 patients had persistent CLBBB. Those that developed CLBBB and AVB had a higher morbidity from hypertension and lower estimated glomerular filtration rate (eGFR). The ECG, TTE, and CT parameters did not differ between the two groups. The ratio of the valve and LVOT area was significantly associated with a higher cumulative risk of events (HR, 3.005; 95% CI, 1.034-8.736; P<0.05). Up to 20% of patients developed new CLBBB or CAVB and more than half were expected to recover. However, it required attention because approximately 40% were persistent. The ratio of the valve to LVOT area was an independent predictor. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Atrial septal aneurysm associated with additional cardiovascular comorbidities in two middle age female patients with ECG signs of right bundle branch block: two case reports.

    Science.gov (United States)

    Bakalli, Aurora; Kamberi, Lulzim; Pllana, Ejup; Gashi, Afrim

    2008-07-19

    Atrial septal aneurysm (ASA) is often associated with other atrial septal abnormalities, particularly with atrial septal defect type ostium secundum or patent foramen ovale. ECG signs of incomplete or complete right bundle branch block are known to be associated with atrial septal defects, however such correlation with other atrial septal abnormalities is not documented. We report here two cases of middle age female patients that presented with dyspnea on physical effort, right bundle branch block (RBBB) on ECG and ASA combined with other cardiac disorders. Transesophageal echocardiography revealed additional information to the ones obtained by surface echocardiography, in both cases. ASA associated with RBBB on ECG may serve as a hint for the presence of additional cardiac abnormalities, thus rousing the demand for a detailed cardiac investigation.

  12. Applicability of a Novel Formula (Bogossian formula) for Evaluation of the QT-Interval in Heart Failure and Left Bundle Branch Block Due to Right Ventricular Pacing.

    Science.gov (United States)

    Frommeyer, Gerrit; Bogossian, Harilaos; Pechlivanidou, Eleni; Conzen, Philipp; Gemein, Christopher; Weipert, Kay; Helmig, Inga; Chasan, Ritvan; Johnson, Victoria; Eckardt, Lars; Hamm, Christian W; Seyfarth, Melchior; Lemke, Bernd; Zarse, Markus; Schmitt, Jörn; Erkapic, Damir

    2017-04-01

    The presence of left bundle branch block (LBBB) due to right ventricular pacing represents a particular challenge in properly measuring the QTc interval. In 2014, a new formula for the evaluation of QT interval in patients with LBBB was reported. 145 patients with implantable cardioverter defibrillator were included in this prospective multicenter observational study. Inclusion criteria were: no permanent right ventricular stimulation, an intrinsic QRS interval of QT-interval must be respected. © 2017 Wiley Periodicals, Inc.

  13. Left bundle-branch block contraction patterns identified from radial-strain analysis predicts outcomes following cardiac resynchronization therapy.

    Science.gov (United States)

    Wang, Chun-Li; Wu, Chia-Tung; Yeh, Yung-Hsin; Wu, Lung-Sheng; Chan, Yi-Hsin; Kuo, Chi-Tai; Chu, Pao-Hsien; Hsu, Lung-An; Ho, Wan-Jing

    2017-06-01

    A left bundle-branch block (LBBB) contraction pattern identified from longitudinal-strain analysis predicts outcomes following cardiac resynchronization therapy (CRT). We investigated the use of an LBBB-contraction pattern identified from radial- or circumferential-strain analysis in the prediction of CRT benefits. Eighty CRT candidates were prospectively enrolled. Before CRT implantation, speckle-tracking analyses in three deformation directions were performed to determine whether an LBBB-contraction pattern was present. The study endpoints were reverse remodeling at 6 months, and adverse outcomes including death or heart failure hospitalization. At 6 months, 49 (61%) patients had reverse remodeling. An LBBB-contraction pattern identified from the radial strain in the mid-ventricular short-axis view or longitudinal strain in the four-chamber view provided excellent true-positive (86%) and false-negative (8%) rates for predicting reverse remodeling. During a median follow-up of 30 months, 31 patients (39%) had adverse outcomes. Absence of an LBBB-contraction pattern in radial (hazard ratio 3.74; 95% confidence interval 1.83-7.62) or longitudinal strain (hazard ratio 3.49; 95% confidence interval 1.71-7.13) was significantly associated with an increased risk of adverse outcomes. Adding the LBBB-pattern assessment by radial-(model χ 2 from 8.2 to 18.5, p = 0.005), or longitudinal-strain analysis (model χ 2 from 8.2 to 16.9, p = 0.011) to a risk model significantly improved the model, including QRS duration and ischemic etiology. In conclusion, an LBBB-contraction pattern identified from radial-strain analysis in the mid-ventricular short-axis view predicted reverse remodeling and outcome following CRT, similarly to the longitudinal-strain analysis.

  14. Differentiating the QRS Morphology of Posterior Fascicular Ventricular Tachycardia From Right Bundle Branch Block and Left Anterior Hemiblock Aberrancy.

    Science.gov (United States)

    Michowitz, Yoav; Tovia-Brodie, Oholi; Heusler, Ishai; Sabbag, Avi; Rahkovich, Michael; Shmueli, Hezzy; Glick, Aharon; Belhassen, Bernard

    2017-09-01

    Left posterior fascicular ventricular tachycardia (LPF-VT) is frequently misdiagnosed as supraventricular tachycardia with aberrant right bundle branch block (RBBB) and left anterior hemiblock (LAHB). The purpose of the present study was to define the morphological ECG characteristics of LPF-VT and attempt to differentiate it from RBBB and LAHB aberrancy. A systematic Medline search was used to identify or locate ECG tracings from patients with LPF-VTs. ECGs with LPF-VT were also collected from patients who underwent ablation of this arrhythmia at the Tel Aviv and Sheba Medical Centers. These ECGs were compared with ECGs of consecutive patients with RBBB and LAHB and no obvious cardiac pathology by echocardiography. Overall, 183 ECGs of LPF-VT were compared with 61 ECGs showing RBBB and LAHB. Univariate analysis demonstrated differences in QRS axis, limb (I, aVr), and precordial (V 1 , V 2 , V 6 ) ECG leads. On multivariate logistic regression analysis, LPF-VT was more often associated with atypical RBBB-like V 1 morphology (odds ratio, 5.1; P =0.004), positive QRS in aVr (odds ratio, 19.2; P <0.001), V 6 R/S ratio ≤1 (odds ratio, 6.7; P =0.01), and QRS ≤140 ms (odds ratio, 7.7; P <0.001). Using these 4 variables, a prediction model was developed that predicted LPF-VT with sensitivity and specificity of 82.1% and 78.3%, respectively. Patients with 3 of 4 positive variables had high probability of having LPF-VT, whereas patients with ≤1 positive variable always had RBBB plus LAHB. The morphological ECG characteristics of LPF-VT were defined, and a high accurate tool for correctly differentiating LPF-VT from RBBB and LAHB aberrancy was developed. © 2017 American Heart Association, Inc.

  15. Comparison of the Electrocardiographic Features of Complete Left Bundle Branch Block in Patients with Ischemic and Nonischemic Left Ventricular Dysfunction

    Directory of Open Access Journals (Sweden)

    Tumer Erdem Guler

    2007-01-01

    Full Text Available Background: Differentiating ischemic (ILVD from nonischemic left ventricular dysfunction (NILVD is important prognostically and therapeutically but might be difficult clinically. The differentiating role of electrocardiographic (ECG features in the presence of left bundle-branch block (LBBB is debatable on differentiating ILVD from NILVD.Objective: The present study assessed whether there is the role of certain ECG features in differentiating ILVD from NILVD in the presence of the complete LBBB.Methods and Results: Patients who had LBBB were divided into two groups based on the presence and type of left ventricular dysfunction; (1 ILVD group (49 patients; 20 female; age: 65 ± 11 years and (2 NILVD group (49 patients; 22 female; age: 59 ± 12 years, and numerous ECG features were compared. Most of these ECG features did not show any difference between the groups except for following ECG findings; the voltage of R wave in V6 were statistically higher in NILVD group compared ILVD group (p: 0.03; the depression of the ST-J point by more than 0.2 mV in V6 were also frequently observed in NILVD group compared ILVD group (5/ 10% vs 19/ 39% , p: 0.001; and the notching in the ascending or descending limb of the S wave in V1-4 leads were more in ILVD group (18/ 36% vs 8/ 16% p: 0.03; 9/ 16% vs 2/ 4%, p: 0.03, respectively.Conclusions: In the current study, although some ECG findings were found to be useful, ECG features in the presence of complete LBBB had poor value in differentiating ILVD from NILVD.

  16. Early Changes in QRS Frequency Following Cardiac Resynchronization Predict Hemodynamic Response in Left Bundle Branch Block Patients.

    Science.gov (United States)

    Niebauer, Mark J; Rickard, John; Tchou, Patrick J; Varma, Niraj

    2016-05-01

    QRS characteristics are the cornerstone of patient selection in cardiac resynchronization therapy (CRT) and the presence of left bundle branch block (LBBB) and baseline QRS ≥150 milliseconds portends a good outcome. We previously showed that baseline QRS frequency analysis adds predictive value to LBBB alone and have hypothesized that a change in frequency characteristics following CRT may produce additional predictive value. We examined the QRS frequency characteristics of 182 LBBB patients before and soon after CRT. Patients were assigned to responder and nonresponder groups. Responders were defined by a decrease in left ventricular end-systolic volume (LVESV) ≥15% following CRT. We analyzed the QRS in ECG leads I, AVF, and V3 before and soon after CRT using the discrete Fourier transform algorithm. The percentage of total QRS power within discrete frequency intervals before and after CRT was calculated. The reduction in lead V3 power <10 Hz was the best indicator of response. Baseline QRS width was similar between the responders and nonresponders (162.2 ± 17.2 milliseconds vs. 158 ± 22.1 milliseconds, respectively; P = 0.180). Responders exhibited a greater reduction in QRS power <10 Hz (-17.0 ± 11.9% vs. -6.6 ± 12.5%; P < 0.001) and a significant AUC (0.743; P < 0.001). A ≥8% decline in QRS power <10 Hz produced the best predictive values (PPV = 84%, NPV = 59%). Importantly, when patients with baseline QRS <150 milliseconds were compared, the AUC improved (0.892, P < 0.001). Successful CRT produces a significant reduction in QRS power below 10 Hz, particularly when baseline QRS <150 milliseconds. These results indicate that QRS frequency changes after CRT provide additional predictive value to QRS alone. © 2016 Wiley Periodicals, Inc.

  17. T-wave area predicts response to cardiac resynchronization therapy in patients with left bundle branch block.

    Science.gov (United States)

    Engels, Elien B; Végh, Eszter M; Van Deursen, Caroline J M; Vernooy, Kevin; Singh, Jagmeet P; Prinzen, Frits W

    2015-02-01

    Chronic heart failure patients with a left ventricular (LV) conduction delay, mostly due to left bundle branch block (LBBB), generally derive benefit from cardiac resynchronization therapy (CRT). However, 30-50% of patients do not show a clear response to CRT. We investigated whether T-wave analysis of the ECG can improve patient selection. The study population comprised 244 CRT recipients with baseline 12-lead electrocardiogram recordings. Echocardiographic response after 6-month CRT was defined as a ≥5% increase in LV ejection fraction (LVEF). Vectorcardiograms (VCGs) were constructed from the measured 12-lead ECGs using an adapted Kors algorithm on digitized ECGs. Logistic regression models indicated repolarization variables as good predictors of CRT response. The VCG-derived T-wave area predicted CRT response (odds ratio [OR] per 10 μVs increase 1.172 [P < 0.001]) even better than QRS-wave area (OR = 1.116 [P = 0.001]). T-wave area had especially predictive value in the LBBB patient group (OR = 2.77 in LBBB vs. 1.09 in non-LBBB). This predictive value persisted after adjustment of multiple covariates, such as gender, ischemia, age, hypertension, coronary artery bypass graft, and the usage of diuretics and β-blockers. In LBBB patients, the increase in LVEF was 6.1 ± 9.7% and 11.3 ± 9.1% in patients with T-wave area below and above the median value, respectively (P < 0.01). In patients with LBBB morphology of the QRS complex, a larger baseline T-wave area is an important independent predictor of LVEF increase following CRT. © 2014 Wiley Periodicals, Inc.

  18. Association of left bundle branch block with obstructive coronary artery disease on coronary CT angiography: a case-control study.

    Science.gov (United States)

    Clerc, Olivier F; Possner, Mathias; Maire, René; Liga, Riccardo; Fuchs, Tobias A; Stehli, Julia; Vontobel, Jan; Mikulicic, Fran; Gräni, Christoph; Benz, Dominik C; Lüscher, Thomas F; Herzog, Bernhard A; Buechel, Ronny R; Kaufmann, Philipp A; Gaemperli, Oliver

    2016-07-01

    Left bundle branch block (LBBB) is considered an unfavourable prognostic marker in patients with underlying heart disease. Testing for coronary artery disease (CAD) is often prompted by incidental LBBB finding, but published studies disagree about a significant association between LBBB and CAD. We therefore assessed the association of LBBB with previously unknown CAD in patients undergoing coronary computed tomography angiography (CCTA). We enrolled 818 patients (mean age 57.2 ± 11.1 years, 106 patients with presumably new LBBB and 712 controls) without known CAD who underwent 64-slice CCTA. Image quality was assessed for each coronary segment. Comparison of obstructive CAD prevalence (defined as ≥50% stenosis) was performed using triple case-matching for pre-test probability (based on age, gender, and symptom typicality) in 101 LBBB patients and 303 matched controls with diagnostic quality in all segments. We found no difference in obstructive CAD prevalence between LBBB patients and matched controls (15 vs. 16%, P = 0.88). Similarly, there were no significant differences in cardiovascular risk factors (CVRF), stenosis severity, CAD extent, non-obstructive CAD, and vessel-based analysis between patient groups. Image quality was very high in LBBB patients and comparable to controls. On multivariate analysis, age, gender, typical angina, and CVRF, but not LBBB (P = 0.94), emerged as significant and independent predictors of obstructive CAD. CAD prevalence is similar in LBBB patients at low-to-moderate pre-test probability compared with controls with similar CVRF matched for age, gender, and symptom typicality. CCTA is a useful imaging modality in LBBB patients, providing comparable image quality to non-LBBB controls. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  19. Painful left bundle branch block syndrome: Clinical and electrocardiographic features and further directions for evaluation and treatment.

    Science.gov (United States)

    Shvilkin, Alexei; Ellis, Ethan R; Gervino, Ernest V; Litvak, Anthony D; Buxton, Alfred E; Josephson, Mark E

    2016-01-01

    Painful left bundle branch block (LBBB) is a rarely diagnosed chest pain syndrome caused by intermittent LBBB in the absence of myocardial ischemia. Its prevalence, mechanism, detailed electrocardiographic (ECG) features, and effective treatments are not well described. The purpose of this study was to characterize clinical and ECG features of patients with painful LBBB syndrome with respect to the LBBB ECG morphology (in particular QRS axis and the precordial S/T wave ratio), clarify diagnostic criteria and possible mechanisms, and provide directions for further evaluation and treatment. We analyzed clinical (n = 50) and ECG (n = 15) features of patients with painful LBBB syndrome (4 patients in our practice and 46 cases identified in the literature). All 15 ECGs of patients with painful LBBB syndrome had an inferior QRS axis and a very low (<1.8) precordial S/T wave ratio, which was consistent with the "new LBBB" pattern. We report a case of painful LBBB syndrome coexisting with coronary artery disease. Right ventricular apical pacing resolved intractable chest pain in 1 case of painful LBBB. Painful LBBB ECG morphology within seconds/minutes of its onset is consistent with the new LBBB pattern with a very low (<1.8) precordial S/T wave ratio and inferior QRS axis. Painful LBBB syndrome can coexist with coronary artery disease, complicating the assessment of chest pain in the setting of LBBB. An electrophysiology study might be considered to investigate whether changing ventricular activation pattern by pacing provides consistent pain control and to select the most effective pacing configuration. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  20. Prognostic Implication of the QRS Axis and its Association with Myocardial Scarring in Patients with Left Bundle Branch Block

    Science.gov (United States)

    Park, Chan Soon; Cha, Myung-jin; Choi, Eue-Keun

    2017-01-01

    Background and Objectives Left bundle branch block (LBBB) with left axis deviation (LAD) has a worse prognosis than LBBB with a normal axis, and myocardial dysfunction has been suggested as a cause of left axis deviation. This study investigated the prognostic significance of the QRS axis in patients with LBBB and analyzed its relationship with the amount of myocardial scarring. Subjects and Methods A total of 829 patients were diagnosed with LBBB at Seoul National University Hospital from October 2004 to June 2014. Of these, 314 who were asymptomatic and had no previous history of cardiac disease were included in the present study. Myocardial scarring was calculated using the Selvester QRS scoring system, and LAD was defined as a QRS axis between -180° and -30°. Results Of the total patients, 91 (29%) had LAD, and patients were followed for a median of 30 months. During follow-up, two patients were hospitalized for de novo heart failure, four had pacemaker implants, and 10 died. There was a significant inverse correlation between myocardial scar score and the QRS axis (r=-0.356, p<0.001). Patients with concomitant LAD had a higher rate of major cardiac adverse events compared with patients with a normal axis (5.5% vs. 1.3%, log-rank p=0.010); the prognostic value was attenuated in multivariable analysis (hazard ratio 4.117; 95% confidence interval 0.955-17.743; p=0.058). Conclusion Concomitant LAD is an indicator of poor prognosis for patients with LBBB and may be associated with greater myocardial scarring. PMID:28382083

  1. Gender, underutilization of cardiac resynchronization therapy, and prognostic impact of QRS prolongation and left bundle branch block in heart failure.

    Science.gov (United States)

    Linde, Cecilia; Ståhlberg, Marcus; Benson, Lina; Braunschweig, Frieder; Edner, Magnus; Dahlström, Ulf; Alehagen, Urban; Lund, Lars H

    2015-03-01

    It has been suggested that cardiac resynchronization therapy (CRT) is less utilized, dyssynchrony occurs at narrower QRS, and CRT is more beneficial in women compared with men. We tested the hypotheses that (i) CRT is more underutilized and (ii) QRS prolongation and left bundle branch block (LBBB) are more harmful in women. We studied 14 713 patients (28% women) with left ventricular ejection fraction (LVEF) <40% in the Swedish Heart Failure Registry. In women vs. men, CRT was present in 4 vs. 7% (P < 0.001) and was absent but with indication in 30 vs. 31% (P = 0.826). Next, among 13 782 patients (28% women) without CRT, 9% of women and 17% of men had non-specific intraventricular conduction delay (IVCD) and 27% of women and 24% of men had LBBB. One-year survival with narrow QRS was 85% in women and 88% in men, with IVCD 74 and 78%, and with LBBB 84 and 82%, respectively. Compared with narrow QRS, IVCD had a multivariable hazard ratio of 1.24 (95% CI 1.05-1.46, P = 0.011) in women and 1.30 (95% CI 1.19-1.42, P < 0.001) in men, and LBBB 1.03 (95% CI 0.91-1.16, P = 0.651) in women and 1.16 (95% CI 1.07-1.26, P < 0.001) in men, P for interaction between gender and QRS morphology, 0.241. While the proportion with CRT was lower in women, CRT was equally underutilized in both genders. QRS prolongation with or without LBBB was not more harmful in women than in men. Efforts to improve CRT implementation should be directed equally towards women and men. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  2. QRS duration in left bundle branch block does not affect left ventricular twisting in chronic systolic heart failure.

    Science.gov (United States)

    Attanà, Paola; Paoletti Perini, Alessandro; Votta, Carmine Domenico; Cappelli, Francesco; Pieragnoli, Paolo; Ricciardi, Giuseppe; Nesti, Martina; Giomi, Andrea; Sacchi, Stefania; Chiostri, Marco; Padeletti, Luigi

    2015-11-01

    Left ventricular (LV) torsion is an important parameter of LV performance and can be influenced by several factors. Aim of this investigation was to evaluate whether QRS prolongation in left bundle branch block (LBBB) may influence global LV twist and twisting/untwisting rate in chronic systolic heart failure (HF) patients. We prospectively evaluated 30 healthy subjects (control group) and 100 chronic HF patients with severely impaired LV systolic function (ejection fraction ≤ 35%). Patients were divided into three groups according to QRS duration: A: QRS 150 ms (n 23). Patients in groups B and C presented LBBB. All subjects underwent standard trans-thoracic echocardiography and two-dimensional speckle-tracking echocardiography evaluation. Categorical variables were compared by the chi-square or the Fisher's exact test. Continuous variables were compared using the ANOVA test. Correlations between variables were analysed with linear regression. Control subjects presented higher torsion parameters, when compared with patients in any HF group. Among the three HF groups, no differences were detected in global twist (4.79 ± 3.54, 3.8 ± 3.0 and 4.15 ± 3.14 degrees, respectively), twist rate max (44.81 ± 25.03, 37.94 ± 19.09 and 37.61 ± 24.49 degrees s(-1), respectively) and untwist rate max (-36.31 ± 30.89, -27.68 ± 34.67 and -39.62 ± 26.27 degrees s(-1), respectively) (P>0.05 for all). At linear regression analysis, there was no relation between QRS duration and any torsion parameter (P>0.05 for all). In patients with chronic severe systolic heart failure, QRS duration and LBBB morphology do not affect LV twisting and untwisting. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  3. Right Bundle Branch Block-Like Pattern During Uncomplicated Right Ventricular Pacing and the Effect of Pacing Site.

    Science.gov (United States)

    Tzeis, Stylianos; Andrikopoulos, George; Weigand, Severin; Grebmer, Christian; Semmler, Verena; Brkic, Amir; Asbach, Stefan; Kloppe, Axel; Lennerz, Carsten; Bourier, Felix; Pastromas, Sokratis; Kolb, Christof

    2016-03-15

    Right bundle branch block (RBBB) configuration is an unexpected finding during right ventricular (RV) pacing that raises the suspicion of inadvertent left ventricular lead positioning. The aim of this study was to evaluate the prevalence of paced RBBB pattern in relation to RV lead location. This is a secondary analysis of a prospective, multicenter study, which randomized implantable cardioverter defibrillator recipients to an apical versus midseptal defibrillator lead positioning. A 12-lead electrocardiogram was recorded during intrinsic rhythm and RV pacing. Paced RBBB-like pattern was defined as positive (>0.05 mV) net amplitude of QRS complex in leads V1 and/or V2. In total, 226 patients (65.6 ± 12.0 years, 20.8% women, 53.1% apical site) were included in the study. The prevalence of paced RBBB pattern in the total population was 15.5%. A significantly lower percentage of patients in the midseptal group demonstrated RBBB-type configuration during RV pacing compared with the apical group (1.9% vs 27.5%, p <0.001). Baseline RBBB, prolonged QRS duration during intrinsic rhythm, and reduced ejection fraction were not associated with increased likelihood of paced RBBB. In the subgroup of patients with RBBB type during pacing, 91.4% of patients had a paced QRS axis from -30° to -90°, whereas 100% of patients displayed a negative QRS vector at lead V3. In conclusion, RBBB configuration is encountered in a considerable percentage of device recipients during uncomplicated RV pacing. Midseptal lead positioning is associated with significantly lower likelihood of paced RBBB pattern compared with apical location. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Does surgically induced right bundle branch block really effect ventricular function in children after ventricular septal defect closure?

    Science.gov (United States)

    Karadeniz, Cem; Atalay, Semra; Demir, Fikri; Tutar, Ercan; Ciftci, Omer; Ucar, Tayfun; Uysalel, Adnan; Eyileten, Zeynep

    2015-03-01

    In this prospective study, we aimed to assess left and right ventricular function in terms of the presence of right bundle branch block (RBBB) in the cases with repaired ventricular septal defect (VSD). Fifty-three patients who had VSD surgery at least 1-year preceding admission and 52 healthy controls were enrolled into the study. All the participants underwent electrocardiographic and echocardiographic examination. The cases with RBBB were determined. The conventional and tissue Doppler echocardiographic measurements of the patients with and without RBBB were compared with each other and healthy controls. Twenty-eight of VSD repair groups were male and 25 were female. Control group consisted of 30 males and 22 females. The mean age of the study and control groups was 7.5 ± 5.0 and 6.9 ± 4.3 years, respectively. RBBB was detected in 20 of 53 (37.7 %) operated patients. The only significant difference between the cases with and without RBBB was decreased right ventricular fractional area change (%) in the former group (33 ± 7 vs. 39 ± 5 p < 0.05). When compared to controls, operated group had statistically lower [corrected] tricuspid annular plane systolic excursion (p < 0.05), lower systolic, early diastolic, and late diastolic myocardial velocities, higher left and right ventricular myocardial performance indices, irrespective of the presence of RBBB. The ratios of mitral or tricuspid inflow to left or right ventricular myocardial in early diastolic velocities measured from lateral annular levels were increased in operated group (all p values <0.05). In conclusion, RBBB in the cases with surgical VSD repair might be associated with right ventricular dysfunction. Biventricular systolic and diastolic dysfunction may develop following VSD repair irrespective of the presence of RBBB. Tissue Doppler-derived myocardial performance indices are useful in detection of those subclinical dysfunctions.

  5. Assessment of Smith Algorithms for the Diagnosis of Acute Myocardial Infarction in the Presence of Left Bundle Branch Block.

    Science.gov (United States)

    Di Marco, Andrea; Anguera, Ignasi; Rodríguez, Marcos; Sionis, Alessandro; Bayes-Genis, Antoni; Rodríguez, Jany; Ariza-Solé, Albert; Sánchez-Salado, José Carlos; Díaz-Nuila, Mario; Masotti, Mónica; Villuendas, Roger; Dallaglio, Paolo; Gómez-Hospital, Joan Antoni; Cequier, Ángel

    2017-07-01

    Recently, a new electrocardiography algorithm has shown promising results for the the diagnosis of acute myocardial infarction in the presence of left bundle branch block (LBBB). We aimed to assess these new electrocardiography rules in a cohort of patients referred for primary percutaneous coronary intervention (pPCI). Retrospective observational cohort study that included all patients with suspected myocardial infarction and LBBB on the presenting electrocardiogram, referred for pPCI to 4 tertiary hospitals in Barcelona, Spain. A total of 145 patients were included. Fifty four (37%) had an ST-segment elevation myocardial infarction (STEMI) equivalent. Among patients with STEMI, 25 (46%) presented in Killip class III or IV, and in-hospital mortality was 15%. Smith I and II rules performed better than Sgarbossa algorithms and showed good specificity (90% and 97%, respectively) but their sensitivity was 67% and 54%, respectively. In a strategy guided by Smith I or Smith II rules, 18 (33%) or 25 (46%) patients with STEMI would have not received a pPCI, respectively. Moreover, the severity and prognosis of STEMI patients was similar regardless of the positivity of Smith rules. Cardiac biomarkers were positive in 54% of non-STEMI patients, limiting their usefulness for initial diagnostic screening. Diagnosis of STEMI in the presence of LBBB remains a challenge. Smith rules can be useful but are limited by suboptimal sensitivity. The search for new electrocardiography algorithms should be encouraged to avoid unnecessary aggressive treatments in the majority of patients, while providing timely reperfusion to a high-risk subgroup of patients. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  6. Mechanical dispersion is associated with poor outcome in heart failure with a severely depressed left ventricular function and bundle branch blocks.

    Science.gov (United States)

    Stankovic, Ivan; Janicijevic, Aleksandra; Dimic, Aleksandra; Stefanovic, Milica; Vidakovic, Radosav; Putnikovic, Biljana; Neskovic, Aleksandar N

    2018-03-01

    Bundle branch blocks (BBB)-related mechanical dyssynchrony and dispersion may improve patient selection for device therapy, but their effect on the natural history of this patient population is unknown. A total of 155 patients with LVEF ≤ 35% and BBB, not treated with device therapy, were included. Mechanical dyssynchrony was defined as the presence of either septal flash or apical rocking. Contraction duration was assessed as time interval from the electrocardiographic R-(Q-)wave to peak longitudinal strain in each of 17 left ventricular segments. Mechanical dispersion was defined as either the standard deviation of all time intervals (dispersion SD ) or as the difference between the longest and shortest time intervals (dispersion delta ). Patients were followed for cardiac mortality during a median period of 33 months. Mechanical dyssynchrony was not associated with survival. More pronounced mechanical dispersion delta was found in patients with dyssynchrony than in those without. In the multivariate regression analysis, patients' functional class, diabetes mellitus and dispersion delta were independently associated with mortality. Mechanical dispersion, but not dyssynchrony, was independently associated with mortality and it may be useful for risk stratification of patients with heart failure (HF) and BBB. Key Messages Mechanical dispersion, measured by strain echocardiography, is associated with poor outcome in heart failure with a severely depressed left ventricular function and bundle branch blocks. Mechanical dispersion may be useful for risk stratification of patients with heart failure and bundle branch blocks.

  7. Sex Differences in Long-Term Outcomes With Cardiac Resynchronization Therapy in Mild Heart Failure Patients With Left Bundle Branch Block.

    Science.gov (United States)

    Biton, Yitschak; Zareba, Wojciech; Goldenberg, Ilan; Klein, Helmut; McNitt, Scott; Polonsky, Bronislava; Moss, Arthur J; Kutyifa, Valentina

    2015-06-29

    Previous studies have shown conflicting results regarding the benefit of cardiac resynchronization therapy (CRT) by sex and QRS duration. In the Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy (MADIT-CRT), we evaluated long-term clinical outcome of heart failure (HF) or death, death, and HF alone by sex and QRS duration (dichotomized at 150 ms) in left bundle-branch block patients with CRT with defibrillator backup (CRT-D) versus implantable cardioverter-defibrillator (ICD) only. There were 394 women (31%) and 887 men with left bundle-branch block. During the median follow-up of 5.6 years, women derived greater clinical benefit from CRT-D compared with implantable cardioverter-defibrillator only, with a significant 71% reduction in HF or death (hazard ratio [HR] 0.29, P150 ms. During long-term follow-up of mild HF patients with left ventricular dysfunction and wide QRS, both women and men with left bundle-branch block derived sustained benefit from CRT-D versus implantable cardioverter-defibrillator only, with significant reduction in HF or death, HF alone, and all-cause mortality regardless of QRS duration. There is an incremental benefit with CRT-D in women for the end points of HF or death and HF alone. URL: https://clinicaltrials.gov/. Unique identifiers: NCT00180271, NCT01294449, and NCT02060110. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  8. Bundle Branch Block

    Science.gov (United States)

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  9. Relation of New Permanent Right or Left Bundle Branch Block on Short- and Long-Term Mortality in Acute Myocardial Infarction Bundle Branch Block and Myocardial Infarction.

    Science.gov (United States)

    Melgarejo-Moreno, Antonio; Galcerá-Tomás, José; Consuegra-Sánchez, Luciano; Alonso-Fernández, Nuria; Díaz-Pastor, Ángela; Escudero-García, Germán; Jaulent-Huertas, Leticia; Vicente-Gilabert, Marta; Galcerá-Jornet, Emilio; Padilla-Serrano, Antonio; de Gea-García, José; Pinar-Bermudez, Eduardo

    2015-10-01

    The aim of this study was to investigate the prognosis associated with bundle branch block (BBB) depending on location, time of appearance, and duration in patients with myocardial infarction (MI). From January 1998 to January 2008, we recruited 5,570 patients with acute MI. Thirty-day and 7-year all-cause mortality, according to BBB location, time of appearance, and duration were analyzed by multivariable analyses. BBB was present in 964 patients (17.3%); right BBB (RBBB) 10.6% and left BBB (LBBB) 6.7%. Overall mortality rate at 30 days was 13.2% (n = 738) and 7 years was 6.34 deaths per 100 patient-year. Both RBBB and LBBB were more frequently previous, 42.9% and 58.8%. Compared with non-BBB, all BBB groups showed higher prevalence of co-morbidities, especially rates of diabetes (49.0% vs 34.3%, p <0.001) and more often heart failure during hospitalization (54.5% vs 26.6%, p <0.001). Compared with RBBB, patients with LBBB had a higher prevalence of co-morbidities and a higher mortality, especially the new BBB, 30 days: 52.5% versus 31.6% and 7 years (incident rate): 27.2 versus 13.3 per 100 patient-year. New transient BBB had lower heart failure on admission (42.6% vs 58.3%, p = 0.008) and 30-day mortality (20.3% vs 69.6%, p <0.001) compared with permanent in both locations. New permanent RBBB was independently associated with 30-day (hazard ratio [HR] 2.01, 95% confidence interval [CI] 1.45 to 2.79) and 7-year mortality (HR 3.12, 95% CI 2.38 to 4.09). New-permanent LBBB was independently associated with 30-day (HR 2.15, 95% CI 1.47 to 3.15) and 7-year mortality (HR 2.91, 95% CI 2.08 to 4.08). In conclusion, in patients with acute MI, the appearance of a new BBB was independently associated with a higher 30-day and 7-year all-cause mortality. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Clinical and angiographic importance of right bundle branch block in the setting of acute anterior myocardial infarction.

    Science.gov (United States)

    Arslan, Uğur; Balcioğlu, Serhat; Tavil, Yusuf; Ozdemir, Murat; Cengel, Atiye

    2008-04-01

    To investigate functional status of patients (Killip class), left ventricular contractility, angiographic anatomy and severity of coronary lesions in patients with and without right bundle branch block (RBBB) in the setting of anterior myocardial infarction (MI). Patients who admitted to coronary care unit with the diagnosis of acute anterior MI between 1999 and 2005 were retrospectively searched from our database. Out of 792 patients, 37 had RBBB (RBBB group) either at admission or in the course of anterior MI. Forty patients who developed no intraventricular conduction defect during the course of anterior MI with the same demographic characteristics were selected as the control group. Out of 37 patients, 30 had RBBB on admission and 7 developed RBBB in the course of acute MI. Left anterior descending artery (LAD) proximal lesion was more commonly detected in the RBBB group [23 (62.2%) vs. 11 (27.5%) patients, p=0.003]. Left ventricular ejection fraction was lower (33.0+/-4.2% vs 36.7+/-4.9%, p=0.003) and end-systolic volume was higher (84.1+/-24.9 ml vs 74.6+/-22.0 ml, p=0.012) in patients with RBBB. Number of patients with high Killip grade (III and IV) was more in the RBBB group [7 (18.9%) vs 3 (7.5%), RR: 1.75, %95 CI 0.92-3.32, p=0.14], and number of patients with Killip grade I was more in the control group [34 (85.0%) vs 22 (59.5%), p=0.012]. Besides mean Killip class was higher in the RBBB group (1.65+/-0.90 vs 1.25+/-0.67, p=0.03). Three patients (8.1%) in the RBBB group and 2 patients (5.0%) in the control group died during hospitalization (p=0.67). Left ventricular ejection fraction decreases and Killip grade increases in case of RBBB in the setting of acute anterior MI. Culprit lesion in patients with RBBB is more commonly a LAD proximal lesion and threatened myocardial tissue is larger in patients with RBBB.

  11. Outcomes With Left Bundle Branch Block and Mildly to Moderately Reduced Left Ventricular Function.

    Science.gov (United States)

    Witt, Chance M; Wu, Gang; Yang, Dachun; Hodge, David O; Roger, Veronique L; Cha, Yong-Mei

    2016-11-01

    This study aimed to define the prognosis for patients with left bundle branch block (LBBB) and a mildly to moderately reduced left ventricular ejection fraction (LVEF) (36% to 50%) as well as to clarify whether LBBB remained a negative prognostic marker in this group. LBBB is associated with worse outcomes in patients with heart failure in the setting of severely reduced LVEF. The level of morbidity and mortality associated with LBBB in the setting of a mildly to moderately reduced LVEF (36% to 50%) has not been clearly characterized. This knowledge is important to clarify the potential benefit of cardiac resynchronization therapy in this group. All patients identified as having an LBBB from 1994 to 2014 were included in the study if they had a baseline echocardiogram within 1 year and an LVEF between 36% and 50%. A control group without intraventricular conduction abnormality matched on age, sex, baseline LVEF, and date of echocardiogram was created. Outcomes were compared between the 2 groups. Of 1,436 patients meeting inclusion criteria, 54% were male. Mean age was 67 ± 13 years, and mean LVEF at baseline was 44 ± 4%. There was no difference in baseline heart failure diagnosis between groups. There were significantly higher rates of baseline coronary artery disease in the control group and higher rates of aortic stenosis in the LBBB group. LBBB was associated with significantly worse mortality (hazard ratio [HR]: 1.17; 95% confidence interval [CI]: 1.00 to 1.36), an LVEF drop to 35% or less (HR: 1.34; 95% CI: 1.09 to 1.63), and the need for an implantable cardioverter-defibrillator (HR: 1.50; 95% CI: 1.10 to 2.10). Mortality remained significantly higher in the LBBB group when controlled for heart failure, coronary artery disease, and aortic stenosis (p = 0.04). Patients with a mildly to moderately reduced LVEF and LBBB have poor clinical outcomes that are significantly worse than those for patients without conduction system disease. This group may obtain

  12. Assessment of left ventricular mechanical dyssynchrony in left bundle branch block canine model: Comparison between cine and tagged MRI.

    Science.gov (United States)

    Saporito, Salvatore; van Assen, Hans C; Houthuizen, Patrick; Aben, Jean-Paul M M; Strik, Marc; van Middendorp, Lars B; Prinzen, Frits W; Mischi, Massimo

    2016-10-01

    To compare cine and tagged magnetic resonance imaging (MRI) for left ventricular dyssynchrony assessment in left bundle branch block (LBBB), using the time-to-peak contraction timing, and a novel approach based on cross-correlation. We evaluated a canine model dataset (n = 10) before (pre-LBBB) and after induction of isolated LBBB (post-LBBB). Multislice short-axis tagged and cine MRI images were acquired using a 1.5 T scanner. We computed contraction time maps by cross-correlation, based on the timing of radial wall motion and of circumferential strain. Finally, we estimated dyssynchrony as the standard deviation of the contraction time over the different regions of the myocardium. Induction of LBBB resulted in a significant increase in dyssynchrony (cine: 13.0 ± 3.9 msec for pre-LBBB, and 26.4 ± 5.0 msec for post-LBBB, P = 0.005; tagged: 17.1 ± 5.0 msec at for pre-LBBB, and 27.9 ± 9.8 msec for post-LBBB, P = 0.007). Dyssynchrony assessed by cine and tagged MRI were in agreement (r = 0.73, P = 0.0003); differences were in the order of time difference between successive frames of 20 msec (bias: -2.9 msec; limit of agreement: 10.1 msec). Contraction time maps were derived; agreement was found in the contraction patterns derived from cine and tagged MRI (mean difference in contraction time per segment: 3.6 ± 13.7 msec). This study shows that the proposed method is able to quantify dyssynchrony after induced LBBB in an animal model. Cine-assessed dyssynchrony agreed with tagged-derived dyssynchrony, in terms of magnitude and spatial direction. J. MAGN. RESON. IMAGING 2016;44:956-963. © 2016 International Society for Magnetic Resonance in Medicine.

  13. Sequential SPECT/CT imaging starting with stress SPECT in patients with left bundle branch block suspected for coronary artery disease.

    Science.gov (United States)

    Engbers, Elsemiek M; Timmer, Jorik R; Mouden, Mohamed; Knollema, Siert; Jager, Pieter L; Ottervanger, Jan Paul

    2017-01-01

    To investigate the impact of left bundle branch block (LBBB) on sequential single photon emission computed tomography (SPECT)/ CT imaging starting with stress-first SPECT. Consecutive symptomatic low- to intermediate-risk patients without a history of coronary artery disease (CAD) referred for SPECT/CT were included from an observational registry. If stress SPECT was abnormal, additional rest SPECT and, if feasible, coronary CT angiography (CCTA) were acquired. Of the 5,018 patients, 218 (4.3 %) demonstrated LBBB. Patients with LBBB were slightly older than patients without LBBB (65±12 vs. 61±11 years, pbundle branch block patients have abnormal stress-first SPECT. • Coronary CT excluded obstructive CAD in many LBBB patients with abnormal SPECT. • Stress-first SPECT imaging is not the optimal imaging protocol in LBBB patients. • In LBBB patients imaging with initial coronary CT may be more appropriate.

  14. QRS frequency characteristics help predict response to cardiac resynchronization in left bundle branch block less than 150 milliseconds.

    Science.gov (United States)

    Niebauer, Mark J; Rickard, John; Polakof, Landon; Tchou, Patrick J; Varma, Niraj

    2014-12-01

    Baseline QRS duration (QRSd) ≥150 ms is a recognized predictor of clinical improvement by cardiac resynchronization therapy (CRT), particularly for those with left bundle branch (LBBB). Patients with QRSd 52% below 10 Hz was especially predictive of response in those with QRSd <150 ms. In these patients, this power threshold was highly predictive of CRT response (positive predictive value 85.7%, negative predictive value 71.4%). In this group of CRT recipients with LBBB, retrospective analysis of QRS frequency content below 10 Hz had greater predictive value for CRT response than baseline QRSd, particularly in those with QRSd <150 ms. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  15. The impact of trans-catheter aortic valve replacement induced left-bundle branch block on cardiac reverse remodeling.

    Science.gov (United States)

    Dobson, Laura E; Musa, Tarique A; Uddin, Akhlaque; Fairbairn, Timothy A; Bebb, Owen J; Swoboda, Peter P; Haaf, Philip; Foley, James; Garg, Pankaj; Fent, Graham J; Malkin, Christopher J; Blackman, Daniel J; Plein, Sven; Greenwood, John P

    2017-02-22

    Left bundle branch block (LBBB) is common following trans-catheter aortic valve replacement (TAVR) and has been linked to increased mortality, although whether this is related to less favourable cardiac reverse remodeling is unclear. The aim of the study was to investigate the impact of TAVR induced LBBB on cardiac reverse remodeling. 48 patients undergoing TAVR for severe aortic stenosis were evaluated. 24 patients with new LBBB (LBBB-T) following TAVR were matched with 24 patients with a narrow post-procedure QRS (nQRS). Patients underwent cardiovascular magnetic resonance (CMR) prior to and 6 m post-TAVR. Measured cardiac reverse remodeling parameters included left ventricular (LV) size, ejection fraction (LVEF) and global longitudinal strain (GLS). Inter- and intra-ventricular dyssynchrony were determined using time to peak radial strain derived from CMR Feature Tracking. In the LBBB-T group there was an increase in QRS duration from 96 ± 14 to 151 ± 12 ms (P < 0.001) leading to inter- and intra-ventricular dyssynchrony (inter: LBBB-T 130 ± 73 vs nQRS 23 ± 86 ms, p < 0.001; intra: LBBB-T 118 ± 103 vs. nQRS 13 ± 106 ms, p = 0.001). Change in indexed LV end-systolic volume (LVESVi), LVEF and GLS was significantly different between the two groups (LVESVi: nQRS -7.9 ± 14.0 vs. LBBB-T -0.6 ± 10.2 ml/m 2 , p = 0.02, LVEF: nQRS +4.6 ± 7.8 vs LBBB-T -2.1 ± 6.9%, p = 0.002; GLS: nQRS -2.1 ± 3.6 vs. LBBB-T +0.2 ± 3.2%, p = 0.024). There was a significant correlation between change in QRS and change in LVEF (r = -0.434, p = 0.002) and between change in QRS and change in GLS (r = 0.462, p = 0.001). Post-procedure QRS duration was an independent predictor of change in LVEF and GLS at 6 months. TAVR-induced LBBB is associated with less favourable cardiac reverse remodeling at medium term follow up. In view of this, every effort should be made to prevent TAVR-induced LBBB

  16. Left Bundle Branch Block Negatively Affects Coronary Flow Velocity Reserve and Myocardial Contractile Reserve in Nonischemic Dilated Cardiomyopathy.

    Science.gov (United States)

    Ciampi, Quirino; Cortigiani, Lauro; Pratali, Lorenza; Rigo, Fausto; Villari, Bruno; Picano, Eugenio; Sicari, Rosa

    2016-02-01

    Coronary flow velocity reserve (CFVR) of the left anterior descending coronary artery (LAD) and myocardial contractile reserve are often impaired in nonischemic dilated cardiomyopathy (DCM). Whether they are affected by the presence of left bundle branch block (LBBB) remains unaddressed. The aim of the study was to investigate how LBBB influences CFVR of the LAD and myocardial contractile reserve in patients with DCM. One hundred eighty-one patients with DCM (116 men; mean age, 63 ± 12 years) underwent high-dose dipyridamole (0.84 mg/kg over 6 min) stress echocardiography with CFVR evaluation of the LAD by Doppler. All patients had ejection fractions  2.0 was considered normal. Inotropic reserve was defined as rest-stress variation in wall motion score index ≥ 0.20. This was a prospective analysis of an unselected sample consecutively enrolled and retrospectively selected. The study group was separated on the basis of presence (n = 122) or absence (n = 59) of LBBB. Patients with LBBB were older (64 ± 11 vs 59 ± 12 years, P = .004) and had reduced resting ejection fractions (30 ± 9% vs 33 ± 7%, P = .02), CFVR of the LAD (1.96 ± 0.41 vs 2.23 ± 0.73, P = .001), and myocardial contractile reserve (variation in wall motion score index, -0.18 ± 0.17 vs -0.33 ± 0.28; P < .001). On multivariate logistic regression analysis, resting ejection fraction (hazard ratio [HR], 1.15; 95% CI, 1.03-1.29; P = .01), smoking habit (HR, 2.63; 95% CI, 1.23-5.62; P = .01), and LBBB (HR, 2.29; 95% CI, 1.05-5.04; P = .04) were independently associated with reduced CFVR, while restrictive transmitral pattern (HR, 2.56; 95% CI, 1.18-5.55; P = .02), end-diastolic volume (HR, 0.98; 95% CI, 0.67-0.99; P = .02), and LBBB (HR, 2.20; 95% CI, 1.11-4.34; P = .02) independently predicted reduced myocardial contractile reserve. CFVR during vasodilator stress echocardiography is a suitable tool for assessing microvascular dysfunction in routine

  17. [Supernormal and alternating conduction in intermittent bundle branch block and intermittent or concealed ventricular preexcitation. Electrophysiological study, mechanisms and clinical considerations].

    Science.gov (United States)

    Costantini, Marcello

    2016-05-01

    Supernormal and alternating conduction are not rare in clinical arrhythmology, detectable at various levels of the conduction system in different pathophysiological conditions, and often associated, so as to justify the search for a possible link between them. In order to define a possible relationship between supernormal and alternating conduction, the electrophysiological data of two patient groups were analyzed. Group 1 included 9 patients with intermittent bundle branch block in the presence of supernormal conduction through the pathological branch. Group 2 included 16 patients with ventricular preexcitation, intermittent or concealed, in the presence of supernormal conduction through the atrioventricular accessory pathway. In group 1, 8 patients had a phase 3 and 1 patient a phase 3 and phase 4 bundle branch block. In all 9 patients, the area of phase 3 block was interrupted by a window of unexpected conductivity detectable by atrial premature stimulation. In 7/9 cases, by modulating the atrial rate, alternating conduction through the branch was observed, and the cardiac cycle of occurrence of the phenomenon was in the range of supernormal conduction in 6/7 cases. In group 2, 11 patients showed conduction through the accessory pathway only for a narrow range of cardiac cycles, during atrial premature stimulation. One patient had a prolonged accessory pathway refractory period (phase 3 block), but a window of unexpected supernormal conduction within the refractory zone was observed at atrial premature stimulation. Another patient presented a tachycardia and bradycardia-dependent block along the accessory pathway (phase 3 and phase 4 block) and the phase 3 block area was interrupted by a window of supernormal conduction. In the other three cases, supernormal conduction was manifested as unexpected resumption of conductivity through the accessory pathway for atrial cycles more precocious than the actual duration of its effective refractoriness. By modulating the

  18. Trastuzumab (Herceptin)-associated cardiomyopathy presented as new onset of complete left bundle-branch block mimicking acute coronary syndrome: a case report and literature review.

    Science.gov (United States)

    Tu, Chung-Ming; Chu, Kai-Ming; Yang, Shin-Ping; Cheng, Shu-Mung; Wang, Wen-Been

    2009-09-01

    Trastuzumab (Herceptin) is well documented in reducing suffering and mortality from breast cancer. The clinically most important side effect of Herceptin is cardiotoxicity, which is reported in 2.6% to 4.5% of patients receiving trastuzumab alone and in as many as 27% of patients when trastuzumab is combined with an anthracycline in metastatic disease. We reported the case of a 50-year-old woman who presented to our emergency department (ED) because of chest pain and shortness of breath. On physical examination, holosystolic murmur over apex could be heard. Pulmonary and abdominal examinations were unremarkable. Twelve-lead electrocardiography showed sinus tachycardia and new onset of complete left bundle-branch block. Emergent transthoracic echocardiography revealed generalized hypokinesia of left ventricle and akinesia over interventricular septum and apex. She subsequently underwent immediate coronary angiography that revealed normal coronary angiography, and left ventriculogram revealed generalized hypokinesia with severe left ventricle dysfunction with ejection fraction of 33%. During right heart catheterization and endomyocardial biopsy, cardiac tamponade developed and was successfully relieved by pericardial window. She was discharged event-free 3 weeks later with conservative treatment. Although new onset of complete left bundle-branch block in a patient with chest pain may be acute coronary syndrome, careful review of medicine history is mandatory to avoid unnecessary procedure and complications.

  19. A case of an infant with bundle branch reentrant ventricular tachycardia

    Directory of Open Access Journals (Sweden)

    Satoki Fujii

    2012-04-01

    Full Text Available Catheter ablation of the right bundle branch was performed on an 11-month-old infant for the treatment of drug-resistant bundle branch reentrant ventricular tachycardia. The occurrence of right bundle branch block could not be used as an endpoint of treatment because the patient had presented with incomplete right bundle branch block pattern during sinus rhythm. We performed ablation of the right bundle branch and utilized changes of duration and morphology of the QRS complex as indicators. Eight years have passed with no development of any atrioventricular block or tachycardia episode.

  20. Severe conduction defects requiring permanent pacemaker implantation in patients with a new-onset left bundle branch block after transcatheter aortic valve implantation.

    Science.gov (United States)

    Nijenhuis, V J; Van Dijk, V F; Chaldoupi, S M; Balt, J C; Ten Berg, J M

    2017-06-01

    Transcatheter aortic valve implantation (TAVI) is frequently associated with cardiac conduction defects (CCD) requiring permanent pacemaker implantation (PPI). Although new-onset left bundle branch block (LBBB) is often seen, the rate of progression to severe CCD is unclear. We aimed to find clinical and electrocardiographic (ECG) parameters associated with severe CCD requiring PPI in patients with a new-onset LBBB after TAVI and assess its effect on clinical outcome. All consecutive patients undergoing TAVI who developed a new-onset LBBB were retrospectively analysed. We excluded patients with pre-existing bundle branch block or pacemaker. Patients were divided into two groups: with or without PPI after TAVI. We included 155 patients (50% female, 80 ± 7 years), of which 37 (24%) developed CCD requiring PPI, mainly due to a total atrioventricular block (n = 17; 46%). Cardiac conduction defects requiring PPI were associated with the following pre-existing parameters: atrial fibrillation (AF), the use of digoxin, CoreValve implantation, and left heart axis. Furthermore, it was associated with the following post-procedural parameters: left heart axis, lower mean heart rate, and prolonged PQ and QRS times. During follow-up, patients with PPI showed a lower mortality rate (11 vs. 29%, P = 0.03). In patients without PPI, mortality was lower in those with narrower QRS complex and transient LBBB. The severity and persistence of a new-onset LBBB after TAVI is associated with mortality. Cardiac conduction defects requiring PPI are associated with prior AF, the use of digoxin, CoreValve implantation, and a left heart axis. In these patients, PPI portends a better prognosis than no PPI.

  1. Structural Causes of Right Bundle Branch Block—Time for a Closer Look?

    Science.gov (United States)

    Ker, James

    2010-01-01

    Right bundle branch block is an electrocardiographic phenomenon with specific criteria. Currently, two specific forms of right bundle branch block are acknowledged, a proximal and a distal variant. A vast array of pathologies can cause proximal, distal or even combined forms of right bundle branch block. In this study it is suggested that a third type of right bundle branch block exist: one caused by a subaortic muscular tendon in the left ventricle, leading to an increased velocity of conduction in the left ventricle, with a resultant “relative” right bundle branch block. It is concluded that it is necessary (and time) to take a closer look at endoventricular structures in the assessment of structural causes of right bundle branch block. PMID:20386615

  2. Long-term outcomes of left bundle branch block in high-risk survivors of acute myocardial infarction: the VALIANT experience

    DEFF Research Database (Denmark)

    Stephenson, Kent; Skali, Hicham; McMurray, John J V

    2006-01-01

    BACKGROUND: In survivors of myocardial infarction (MI), new left bundle branch block (LBBB) is associated with adverse outcomes, but its impact is not well described in post-MI patients with left ventricular (LV) systolic dysfunction and/or heart failure (HF). OBJECTIVES: The aim of this study...... was to determine if new LBBB is an independent predictor of long-term fatal and nonfatal outcomes in high-risk survivors of MI by reviewing data from the VALsartan In Acute myocardial iNfarcTion (VALIANT) trial. METHODS: In VALIANT, 14,703 patients with LV systolic dysfunction and/or HF were randomized...... to valsartan, captopril, or both a mean of 5 days after MI. Baseline ECG data were available from 14,259 patients. We assessed the predictive value of new LBBB for death and major cardiovascular outcomes after 3 years, adjusting for multiple baseline covariates including LV ejection fraction. RESULTS...

  3. Do patients with heart failure and right bundle branch block need biventricular pacing? A case of significant QRS narrowing by right ventricular pacing alone.

    Science.gov (United States)

    Crea, Pasquale; Andò, Giuseppe; Zagari, Domenico; Giordano, Antonio; Picciolo, Giuseppe; Oreto, Giuseppe

    2015-01-01

    We report the case of a 56-year-old male with ischemic cardiomyopathy, severe left ventricular dysfunction and right bundle branch block (RBBB) with a wide QRS duration (180ms) who received dual-chamber implantable cardioverter-defibrillator for primary prevention of sudden death. After having placed the right ventricular lead in the middle of the inter-ventricular septum, a significant narrowing of QRS duration was observed, thus obtaining "de facto" a cardiac resynchronization therapy (CRT). This type of cardiac pacing could be an alternative to conventional CRT with left ventricular pacing in patients with wide QRS due to RBBB. The long-term effects of this RV only pacing strategy with ICD in patients with heart failure yet remain to be determined. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Cardiac resynchronization therapy for exercise-induced left ventricular dysfunction in the setting of left bundle branch block: A case report and review of the literature

    Directory of Open Access Journals (Sweden)

    JoEllyn M. Abraham, MD

    2014-12-01

    Full Text Available Exercise-induced dyspnea is one of the most common symptoms that cause a patient to see a physician and a broad differential diagnosis is required. In this case report, we describe a patient with this complaint who had a left bundle branch block and preserved left ventricular function at rest. On stress echocardiography, she had significant exercise-induced left ventricular dysfunction and associated mitral regurgitation but a coronary angiogram demonstrated normal coronary arteries. Both of the echocardiographic findings, as well as her symptoms, improved with the placement of a bi-ventricular pacemaker. A brief review of the literature on cardiac resynchronization therapy for indications beyond the current guidelines is also provided.

  5. Outcome after implantation of cardiac resynchronization/defibrillation systems in patients with congestive heart failure and left bundle-branch block.

    Science.gov (United States)

    Pfau, Giselher; Schilling, Thomas; Kozian, Alf; Lux, Anke; Götte, A; Huth, Christof; Hachenberg, Thomas

    2010-02-01

    The implantation of cardiac resynchronization/defibrillation devices (CRT-Ds) increasingly is used in patients with congestive heart failure and left bundle-branch block. There are no data on the effects of anesthesia and surgery on outcome after implantation. A retrospective, observational study; postoperative survey. University hospital. Three hundred forty-one patients (258 men/83 women, 63 +/- 9 years) with congestive heart failure and left bundle-branch block who underwent CRT-D implantation in 1996 to 2005. Perioperative data were retrieved from the patients' records. Cardiologists caring for the patients were contacted to obtain information on current New York Heart Association (NYHA) status and mortality after CRT-D implantation. Preoperatively, 45 patients were classified as NYHA II, 246 as NYHA III, and 50 as NYHA IV. CRT was performed via thoracotomy in 100 and transvenously in 241 cases. General anesthesia (propofol or sevoflurane and remifentanil) was performed in 273 and local anesthesia (lidocaine) in 68 patients. Hypotension occurred mainly during general anesthesia (43% v 4%). The 30-day mortality was 0%. The postoperative survey started in 2006 and was completed by 215 patients. The mean survival time was 77 months; 151 patients survived the study period. Outcome was not influenced by local and general anesthesia. Presence of preoperative NYHA class >II (odds ratio [OR] = 1.6, confidence interval [CI] = 0.5-5.1), mitral regurgitation (OR = 2.5, CI = 1.2-5.5), and serum creatinine >1.1 mg/dL (OR = 3.0, CI = 1.5-6.2) resulted in an inferior prognosis. In patients with severely impaired cardiac function, general anesthesia for the implantation of a biventricular pacing device can be used with justifiable risk. The method of anesthesia did not influence outcome. Copyright 2010 Elsevier Inc. All rights reserved.

  6. Longer right to left ventricular activation delay at cardiac resynchronization therapy implantation is associated with improved clinical outcome in left bundle branch block patients.

    Science.gov (United States)

    Kosztin, Annamaria; Kutyifa, Valentina; Nagy, Vivien Klaudia; Geller, Laszlo; Zima, Endre; Molnar, Levente; Szilagyi, Szabolcs; Ozcan, Emin Evren; Szeplaki, Gabor; Merkely, Bela

    2016-04-01

    Data on longer right to left ventricular activation delay (RV-LV AD) predicting clinical outcome after cardiac resynchronization therapy (CRT) by left bundle branch block (LBBB) are limited. We aimed to evaluate the impact of RV-LV AD on N-terminal pro-B-type natriuretic peptide (NT-proBNP), ejection fraction (EF), and clinical outcome in patients implanted with CRT, stratified by LBBB at baseline. Heart failure (HF) patients undergoing CRT implantation with EF ≤ 35% and QRS ≥ 120 ms were evaluated based on their RV-LV AD at implantation. Baseline and 6-month clinical parameters, EF, and NT-proBNP values were assessed. The primary endpoint was HF or death, the secondary endpoint was all-cause mortality. A total of 125 patients with CRT were studied, 62% had LBBB. During the median follow-up of 2.2 years, 44 (35%) patients had HF/death, 36 (29%) patients died. Patients with RV-LV AD ≥ 86 ms (lower quartile) had significantly lower risk of HF/death [hazard ratio (HR): 0.44; 95% confidence interval (95% CI): 0.23-0.82; P = 0.001] and all-cause mortality (HR: 0.48; 95% CI: 0.23-1.00; P = 0.05), compared with those with RV-LV AD bundle branch block patients with longer RV-LV activation delay at CRT implantation had greater improvement in NT-proBNP, EF, and significantly better clinical outcome. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

  7. Prominent R wave in ECG lead V1 predicts improvement of left ventricular ejection fraction after cardiac resynchronization therapy in patients with or without left bundle branch block.

    Science.gov (United States)

    Bode, Weeranun D; Bode, Michael F; Gettes, Leonard; Jensen, Brian C; Mounsey, John P; Chung, Eugene H

    2015-10-01

    QRS morphology on postprocedural ECG indicating posterolateral left ventricular pacing may be predictive of response to cardiac resynchronization therapy (CRT). The purpose of this study was to assess whether a positive vector in V1 and/or negative vector in lead I on the first postprocedural ECG, suggesting posterolateral capture from CRT, correlates with improvement in left ventricular ejection fraction (LVEF). A retrospective chart review was conducted on all patients who underwent CRT implantation at our institution between April 2008 and December 2011. Biventricular (BiV) paced QRS morphology was defined as R/S ≥1 in V1 and/or R/S ≤ 1 in lead I. The primary outcome was improvement of LVEF ≥7.5%. The χ(2) and t tests were used for analysis. Of 68 patients, 49 (72%) met our BiV paced QRS morphology criteria. Thirty-four of these 49 patients (69%) had improvement in LVEF. Of the 19 patients who did not meet our criteria, 17 (89%) did not have an improvement in LVEF (sensitivity 94%, specificity 53%, χ(2) = 19.04, P bundle branch block was not a predictor of echocardiographic response. Our results highlight the importance of periprocedural ECG analysis to optimize response to CRT. Moreover, patients without left bundle branch block still benefited from CRT if they met our BiV paced morphology criteria. This suggests that postprocedural left ventricular activation as reflected on the ECG may supersede the baseline conduction delay. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  8. Coronary sinus activation patterns in patients with and without left bundle branch block undergoing electroanatomic mapping system-guided cardiac resynchronization therapy device implantation.

    Science.gov (United States)

    Del Greco, Maurizio; Zorzi, Alessandro; Di Matteo, Irene; Cima, Anna; Maines, Massimiliano; Angheben, Carlo; Catanzariti, Domenico

    2017-02-01

    Implantation of the left ventricular (LV) lead in segments with delayed electrical activation may improve response to cardiac resynchronization therapy (CRT). The purpose of this study was to evaluate the amount and regional distribution of LV electrical delay (LVED) in patients with or without left bundle branch block (LBBB). We enrolled 60 patients who underwent electroanatomic mapping system-guided CRT device implantation. Activation mapping of the coronary sinus (CS) branches was performed using an insulated guidewire. LVED was defined as the interval between the beginning of the QRS complex on the surface electrocardiogram (ECG) and the local electrogram and expressed in milliseconds or as percentage of the total QRS duration (LVED%). Forty-three patients showed a LBBB and 17 a non-LBBB electrocardiographic pattern. A total of 148 CS branches (mean 2.5 per patient; range 2-4 per patient) were mapped. Patients with LBBB showed higher maximum LVED (135 ms [108-150 ms] vs 100 ms [103-110 ms]; P branches showing LVED >50% of the total QRS duration, >75% of the total QRS duration, and >85 ms was significantly higher in patients with LBBB than in patients without LBBB. Patients without LBBB showed lower LVED and more heterogeneous electrical activation of the CS than did patients with LBBB. This finding may contribute to a lower rate of response to CRT of patients without LBBB and suggests the use of activation mapping to guide LV lead placement. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  9. PR interval identifies clinical response in patients with non-left bundle branch block: a Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy substudy.

    Science.gov (United States)

    Kutyifa, Valentina; Stockburger, Martin; Daubert, James P; Holmqvist, Fredrik; Olshansky, Brian; Schuger, Claudio; Klein, Helmut; Goldenberg, Ilan; Brenyo, Andrew; McNitt, Scott; Merkely, Bela; Zareba, Wojciech; Moss, Arthur J

    2014-08-01

    In Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy (MADIT-CRT), patients with non-left bundle branch block (LBBB; including right bundle branch block, intraventricular conduction delay) did not have clinical benefit from cardiac resynchronization therapy with defibrillator (CRT-D). We hypothesized that baseline PR interval modulates clinical response to CRT-D therapy in patients with non-LBBB. Non-LBBB patients (n=537; 30%) were divided into 2 groups based on their baseline PR interval as normal (including minimally prolonged) PR (PR <230 ms) and prolonged PR (PR ≥230 ms). The primary end point was heart failure or death. Separate secondary end points included heart failure events and all-cause mortality. Cox proportional hazards regression models were used to compare risk of end point events by CRT-D to implantable cardioverter defibrillator therapy in the PR subgroups. There were 96 patients (22%) with a prolonged PR and 438 patients (78%) with a normal PR interval. In non-LBBB patients with a prolonged PR interval, CRT-D treatment was associated with a 73% reduction in the risk of heart failure/death (hazard ratio, 0.27; 95% confidence interval, 0.13-0.57; P<0.001) and 81% decrease in the risk of all-cause mortality (hazard ratio, 0.19; 95% confidence interval, 0.13-0.57; P<0.001) compared with implantable cardioverter defibrillator therapy. In non-LBBB patients with normal PR, CRT-D therapy was associated with a trend toward an increased risk of heart failure/death (hazard ratio, 1.45; 95% confidence interval, 0.96-2.19; P=0.078; interaction P<0.001) and a more than 2-fold higher mortality (hazard ratio, 2.14; 95% confidence interval, 1.12-4.09; P=0.022; interaction P<0.001) compared with implantable cardioverter defibrillator therapy. The data support the use of CRT-D in MADIT-CRT non-LBBB patients with a prolonged PR interval. In non-LBBB patients with a normal PR interval, implantation of a CRT-D may be deleterious

  10. Different patterns of bundle-branch blocks and the risk of incident heart failure in the Women's Health Initiative (WHI) study.

    Science.gov (United States)

    Zhang, Zhu-ming; Rautaharju, Pentti M; Soliman, Elsayed Z; Manson, Joann E; Martin, Lisa W; Perez, Marco; Vitolins, Mara; Prineas, Ronald J

    2013-07-01

    We evaluated the risk of incident heart failure (HF) associated with bundle-branch blocks (BBBs) in postmenopausal women. Cox's regression was used to evaluate hazard ratios with 95% confidence intervals for HF among 65975 participants of the Women's Health Initiative (WHI) study during an average follow-up of 14 years. BBBs observed in 1676 women at baseline were categorized into left, right, and indetermined-type BBBs (LBBB, RBBB, and intraventricular conduction defect, respectively). Compared with women with no BBB, LBBB, and intraventricular conduction defect were strong predictors of incident HF in multivariable-adjusted risk models (hazard ratio, 3.79; confidence interval, 2.95-4.87 for LBBB and hazard ratio, 3.53; confidence interval, 2.14-5.81 for intraventricular conduction defect). RBBB was not a significant predictor of incident HF in multivariable-adjusted risk model, but the combination of RBBB and left anterior fascicular block was a strong predictor (hazard ratio, 2.96; confidence interval, 1.77-4.93). QRS duration was an independent predictor of incident HF only in LBBB, with more pronounced risk at QRS ≥ 140 ms than at <140 ms. QRS nondipolar voltage (RNDPV) was an independent predictor in both RBBB and LBBB and, in addition, in LBBB, QRS/STT angle and ST J-point depression in aVL were independent predictors. LBBB, intraventricular conduction defect, and RBBB combined with left anterior fascicular block are strong predictors of incident HF in multivariable-adjusted risk models, but RBBB is not a significant predictor. QRS duration ≥ 140 ms may warrant consideration in LBBB as an indication for further diagnostic evaluation for possible therapeutic and preventive action. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000611.

  11. Sequential SPECT/CT imaging starting with stress SPECT in patients with left bundle branch block suspected for coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Engbers, Elsemiek M.; Mouden, Mohamed [Isala, Department of Cardiology, Zwolle (Netherlands); Isala, Department of Nuclear Medicine, Zwolle (Netherlands); Timmer, Jorik R.; Ottervanger, Jan Paul [Isala, Department of Cardiology, Zwolle (Netherlands); Knollema, Siert; Jager, Pieter L. [Isala, Department of Nuclear Medicine, Zwolle (Netherlands)

    2017-01-15

    To investigate the impact of left bundle branch block (LBBB) on sequential single photon emission computed tomography (SPECT)/ CT imaging starting with stress-first SPECT. Consecutive symptomatic low- to intermediate-risk patients without a history of coronary artery disease (CAD) referred for SPECT/CT were included from an observational registry. If stress SPECT was abnormal, additional rest SPECT and, if feasible, coronary CT angiography (CCTA) were acquired. Of the 5,018 patients, 218 (4.3 %) demonstrated LBBB. Patients with LBBB were slightly older than patients without LBBB (65±12 vs. 61±11 years, p<0.001). Stress SPECT was more frequently abnormal in patients with LBBB (82 % vs. 46 %, p<0.001). After reviewing stress and rest images, SPECT was normal in 43 % of the patients with LBBB, compared to 77 % of the patients without LBBB (p<0.001). Sixty-four of the 124 patients with LBBB and abnormal stress-rest SPECT underwent CCTA (52 %), which could exclude obstructive CAD in 46 of the patients (72 %). Sequential SPECT/CT imaging starting with stress SPECT is not the optimal imaging protocol in patients with LBBB, as the majority of these patients have potentially false-positive stress SPECT. First-line testing using CCTA may be more appropriate in low- to intermediate-risk patients with LBBB. (orig.)

  12. The prognostic value of a new left bundle branch block in patients with acute myocardial infarction: A systematic review and meta-analysis.

    Science.gov (United States)

    Al Rajoub, Belal; Noureddine, Samar; El Chami, Samer; Haidar, Mohamad Hussein; Itani, Bachir; Zaiter, Aida; Akl, Elie A

    To assess the prognostic value of new left bundle branch block (LBBB) in patients with acute myocardial infarction (AMI). LBBB develops in many cardiac conditions, including AMI. The empirical evidence for the contribution of LBBB to mortality in AMI is not consistent. Medline, PubMed, CINAHL, and EMBASE were searched. Inverse variance meta-analysis was performed with odds ratios as the effect estimates. The I 2 statistic and risk of bias were assessed. Eight studies involving 105,861 participants were eligible. New LBBB was associated with higher mortality at 30 days (OR: 2.10, 95% CI 1.27 to 3.48) and 1-year follow up (OR: 2.81, 95% CI 1.64 to 4.80), and increased heart failure risk (OR: 2.64, 95% CI 1.84 to 3.77). AMI patients with new LBBB are a high risk group and must be treated accordingly. Yet, more research is needed given the limitations of studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Comparison of Incidence of Left Ventricular Systolic Dysfunction Among Patients With Left Bundle Branch Block Versus Those With Normal QRS Duration.

    Science.gov (United States)

    Sze, Edward; Dunning, Allison; Loring, Zak; Atwater, Brett D; Chiswell, Karen; Daubert, James P; Kisslo, Joseph A; Mark, Daniel B; Velazquez, Eric J; Samad, Zainab

    2017-12-01

    We compared the incidence of left ventricular systolic dysfunction (LVSD) among patients with left bundle branch block (LBBB) to a matched cohort of patients with a narrow QRS duration <120 ms (NQRS). We hypothesized patients with preserved ejection fraction (EF) ≥50% and LBBB would have higher incidence of LVSD compared with a matched population of NQRS patients. Patients with LBBB on electrocardiogram within 30 days of a baseline echocardiogram with EF ≥50%, who had at least 1 follow-up echocardiogram ≥6 months later, were matched 1:1 on risk factors for cardiomyopathy to patients with NQRS. Incident LVSD was defined as a decline in EF to ≤45% on follow-up echocardiogram, or heart transplant, receipt of a cardiac device for LVSD (defibrillator or biventricular pacemaker), or implantation of a left ventricular assist device ≥6 months post baseline echocardiogram. Relative risk was calculated using conditional Poisson regression techniques. The final study cohort consisted of 188 patients, 94 with LBBB and 94 with NQRS. On follow-up, progression to LVSD was noted in 36% of LBBB patients and 10% of NQRS patients. The relative risk for LVSD in patients with LBBB was 3.78 (95% confidence interval = 1.98 to 7.19). In conclusion, there is a strong association between LBBB and the subsequent development of LVSD independent of common risk factors for cardiomyopathy. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Specificity for each of the 46 criteria of the Selvester QRS score for electrocardiographic myocardial scar sizing in left bundle branch block.

    Science.gov (United States)

    Åkerlund, Sofia; Wieslander, Björn; Turesson, Madeleine; Nijveldt, Robin; Klem, Igor; Almer, Jakob; Engblom, Henrik; Wagner, Galen S; Atwater, Brett D; Ugander, Martin

    2015-01-01

    The Selvester QRS score consists of a set of electrocardiographic criteria designed to identify, quantify and localize scar in the left ventricle using the morphology of the QRS complex. These criteria were updated in 2009 to expand their use to patients with underlying conduction abnormalities, but these versions have thus far only been validated in small and carefully selected populations. To determine the specificity for each of the criteria of the left bundle branch block (LBBB) modified Selvester QRS Score (LB-SS) in a population with strict LBBB and no myocardial scar as verified by cardiovascular magnetic resonance imaging with late gadolinium enhancement (CMR-LGE). We identified ninety-nine patients with LBBB without scar on CMR-LGE, who underwent a clinically indicated CMR scan at three different centers. The ECG recording date was any time prior to or <30days after the CMR scan. The LB-SS was applied and specificity for detection of scar in each of the 46 separate criteria was determined. The specificity ranged between 41% and 100% for the 46 criteria of LB-SS and 27/46 (59%) met ≥95% specificity. The mean±SD specificity was 90%±14%. Several of the criteria in the LB-SS lack adequate specificity. Elimination or modification of these nonspecific QRS morphology criteria may improve the specificity of the overall LB-SS. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. The Prognostic Impact of New-Onset Persistent Left Bundle Branch Block Following Transcatheter Aortic Valve Implantation: A Meta-analysis.

    Science.gov (United States)

    Ando, Tomo; Takagi, Hisato

    2016-09-01

    New-onset persistent left bundle branch block (NOP-LBBB) is one of the most common conduction disturbances after transcatheter aortic valve implantation (TAVI). We hypothesized that NOP-LBBB may have a clinically negative impact after TAVI. To find out, we conducted a systematic literature search of the MEDLINE/PubMed and Embase databases. Observational studies that reported clinical outcomes of NOP-LBBB patients after TAVI were included. The random-effects model was used to combine odds ratios, risk ratios, or hazard ratios (HRs) with 95% confidence intervals. Adjusted HRs were utilized over unadjusted HRs or risk ratios when available. A total of 4049 patients (807 and 3242 patients with and without NOP-LBBB, respectively) were included. Perioperative (in-hospital or 30-day) and midterm all-cause mortality and midterm cardiovascular mortality were comparable between the groups. The NOP-LBBB patients experienced a higher rate of permanent pacemaker implantation (HR: 2.09, 95% confidence interval: 1.12-3.90, P = 0.021, I(2) = 83%) during midterm follow-up. We found that NOP-LBBB after TAVI resulted in higher permanent pacemaker implantation but did not negatively affect the midterm prognosis. Therefore, careful observation during the follow-up is required. © 2016 Wiley Periodicals, Inc.

  16. New-onset left bundle branch block-associated idiopathic nonischemic cardiomyopathy and left ventricular ejection fraction response to guideline-directed therapies: The NEOLITH study.

    Science.gov (United States)

    Wang, Norman C; Singh, Madhurmeet; Adelstein, Evan C; Jain, Sandeep K; Mendenhall, G Stuart; Shalaby, Alaa A; Voigt, Andrew H; Saba, Samir

    2016-04-01

    Left ventricular ejection fraction (LVEF) response to guideline-directed medical therapy (GDMT) and to early cardiac resynchronization therapy (CRT) in new-onset idiopathic nonischemic cardiomyopathy (NICM) and left bundle branch block (LBBB) is not well described. CRT is recommended if LVEF remains ≤35% after at least 3 months of GDMT. The purpose of this study was to describe LVEF response to GDMT at 3 months and to early CRT in new-onset LBBB-associated idiopathic NICM. A retrospective cohort study was performed in subjects with new-onset idiopathic NICM, LVEF ≤35%, and LBBB or narrow (35% in 39 narrow QRS complex subjects (56%) and 2 LBBB subjects (6%) (P 35% (relative risk 10.30; 95% confidence interval 2.63-40.27; P = .0008) and absolute difference between post-GDMT LVEF and initial LVEF (β = 16.296; standard error = 2.977; P < .0001) in final multivariable analyses. CRT super-response, defined as post-CRT LVEF ≥50%, was observed in 8 of LBBB subjects (35%) who received CRT. GDMT did not significantly improve LVEF in new-onset LBBB-associated idiopathic NICM at 3 months. Most remained candidates for CRT, and a high percentage were super-responders. Optimal timing for CRT implantation requires further investigation. Copyright © 2016 Heart Rhythm Society. All rights reserved.

  17. Complete left bundle branch block and smaller left atrium are predictors of response to cardiac resynchronization therapy in advanced heart failure.

    Science.gov (United States)

    Imamura, Teruhiko; Kinugawa, Koichiro; Nitta, Daisuke; Komuro, Issei

    2015-01-01

    We previously reported that cardiac resynchronization therapy with defibrillator (CRT-D) is not an appropriate rescue strategy in patients with advanced heart failure (HF), especially those dependent on inotrope infusion, and instead early ventricular assist device (VAD) implantation should be considered. Predictors of response to CRT in such populations, however, remain uncertain. We studied 67 inpatients aged 10% at 6-month follow up. On logistic regression analysis, LA volume index (LAVI) bundle branch block (CLBBB; OR, 6.663; P=0.032) were significant predictors of response to CRT-D among the baseline variables. Patients with both predictors were associated with improvements in LVEF and plasma B-type natriuretic peptide compared with those with none of these predictors during the 6-month follow up period (P<0.05 for both). VAD-free survival rate was significantly higher in the responders compared with the non-responders during the 2-year study period (86% vs. 52%, P=0.044). CLBBB and smaller LAVI are novel predictors of response in patients with advanced HF receiving CRT-D in real-world practice. Such responders may be better candidates for CRT-D and delay of cardiac replacement therapy.

  18. A new experimentally validated formula to calculate the QT interval in the presence of left bundle branch block holds true in the clinical setting.

    Science.gov (United States)

    Bogossian, Harilaos; Frommeyer, Gerrit; Ninios, Ilias; Pechlivanidou, Eleni; Hasan, Fuad; Nguyen, Quy Suu; Mijic, Dejan; Kloppe, Axel; Karosiene, Zana; Margkarian, Artak; Bandorski, Dirk; Schultes, Dominik; Erkapic, Damir; Seyfarth, Melchior; Lemke, Bernd; Eckardt, Lars; Zarse, Markus

    2017-03-01

    The evaluation of the QT interval in the presence of left bundle branch block (LBBB) is associated with the challenge to discriminate native QT interval from the prolongation due to the increase in QRS duration. The newest formula to evaluate QT interval in the presence of LBBB suggests: modified QT during LBBB = measured QT interval minus 50% of LBBB duration. The purpose of this study is therefore to validate the abovementioned formula in the clinical setting. Validation in two separate groups of patients: Patients who alternated between narrow QRS and intermittent LBBB and patients with narrow QRS who developed LBBB after transcatheter aortic valve implantation (TAVI). The acquired mean native QTc intervals and those calculated by the presented formula displayed no significant differences (p > .99 and p > .75). In this study we proved for the first time the validity and applicability of the experimentally acquired formula for the evaluation of the QT interval in the presence of LBBB in a clinical setting. © 2016 Wiley Periodicals, Inc.

  19. Prolonged QRS duration (QRS >/=170 ms) and left axis deviation in the presence of left bundle branch block: A marker of poor left ventricular systolic function?

    Science.gov (United States)

    Das, M K; Cheriparambil, K; Bedi, A; Kassotis, J; Reddy, C V; Makan, M; Dunbar, C C; Saul, B

    2001-11-01

    Left bundle branch block (LBBB) is commonly associated with structural heart disease and left ventricular dysfunction. We propose that the QRS duration and degree of left-axis deviation (LAD) identify significant left ventricular systolic dysfunction in patients with LBBB. In this prospective study the ejection fraction (EF) of 300 consecutive patients with LBBB was evaluated by echocardiography. The relationship between QRS duration and LAD (axis between -30 degrees and -90 degrees ) and EF were derived. There was no significant difference in age, sex, presence of ischemic or nonischemic cardiomyopathy and valvular heart disease, and EF among the patients with or without LAD. The EF of patients with QRS >/=170 milliseconds with LAD (n = 20) and without LAD (n = 18) was 25% +/- 16% and 23% +/- 13%, respectively (P =.71). The mean EF (24% +/- 10%) of the patients with a QRS duration of >/=170 milliseconds (n = 38) was significantly lower than the mean EF (36% +/- 16%) of the patients with a QRS duration of axis was not significantly correlated with EF and did not have added predictive value. The QRS duration has a significant inverse relationship with EF and prolongation of QRS duration (>/=170 milliseconds) in the presence of LBBB is a marker of significant left ventricular systolic dysfunction. The presence of LAD in LBBB does not signify a further decrease in EF.

  20. Impact on Left Ventricular Function and Remodeling and on 1-Year Outcome in Patients With Left Bundle Branch Block After Transcatheter Aortic Valve Implantation.

    Science.gov (United States)

    Carrabba, Nazario; Valenti, Renato; Migliorini, Angela; Marrani, Marco; Cantini, Giulia; Parodi, Guido; Dovellini, Emilio Vincenzo; Antoniucci, David

    2015-07-01

    Conflicting results have been reported about the prognostic impact of left bundle branch block (LBBB) after transcatheter aortic valve implantation (TAVI). The aim of this study was to evaluate the impact of LBBB after TAVI on left ventricular (LV) function and remodeling and on 1-year outcomes. Of 101 TAVI patients, 9 were excluded. All complications were evaluated according to the Valve Academic Research Consortium 2 definition. Of 92 patients, 34 developed LBBB without more advanced myocardial damage or inflammation biomarkers in comparison with patients without LBBB. The only predictor of new LBBB was larger baseline LV end-diastolic volume. LBBB plus advanced atrioventricular block was strongly correlated with permanent pacemaker implantation (p <0.0001). Patients with LBBB had a higher rate of permanent pacemaker implantation at 30 days (59% vs 19%, p <0.0001) and less recovery of LV systolic function and a trend toward a lower rate of LV reverse remodeling at 1 year. The development of acute kidney injury and the logistic European System for Cardiac Operative Risk Evaluation score were associated with poor outcomes (all-cause mortality and heart failure) (hazard ratio 6.86, 95% confidence interval 2.51 to 18.74, p <0.0001, and hazard ratio 1.04, 95% confidence interval 1.01 to 1.08, p = 0.021, respectively), but not LBBB. In conclusion, after TAVI, 37% of patients developed new LBBB without more advanced myocardial damage or inflammation biomarkers. LBBB was associated with a higher rate of permanent pacemaker implantation, which negatively affected the recovery of LV systolic function. The development of acute kidney injury, rather than LBBB, increases the 1-year risk for mortality and hospitalization for heart failure. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. The impact of electrocardiographic left ventricular hypertrophy and bundle branch block on the triage and outcome of ED patients with a suspected acute coronary syndrome: a multicenter study.

    Science.gov (United States)

    Pope, J Hector; Ruthazer, Robin; Kontos, Michael C; Beshansky, Joni R; Griffith, John L; Selker, Harry P

    2004-05-01

    We studied the impact on triage and outcome of the presence of left ventricular hypertrophy (LVH) and left/right bundle branch block (LBBB/RBBB) on the initial ED electrocardiogram (ECG) for patients with symptoms suggestive of an acute coronary syndrome (ACS). Secondary analysis of data from a prospective clinical trial of patients with chest pain or other symptoms suggesting ACS in six U.S. hospitals comparing patient demographics, clinical variables, and outcomes was used. Of 5,324 study patients, 3% had ECG-LVH, 3% had LBBB, 3% had RBBB, and 43% had ischemic ST segment or T wave abnormalities. Compared with patients without ST segment or T wave abnormalities, patients with ECG-LVH or BBB were older and were more likely to have a chief complaint of shortness of breath or a history of cardiac or related diseases. Patients with ECG-LVH or BBB had more diagnoses of congestive heart failure (CHF) and ACS compared with patients without these ECG abnormalities and were just as likely to have ACS as their diagnosis compared with patients with ischemic ST segment or T wave abnormalities. Having ECG-LVH or BBB did not alter the true-positive rate for ACS but increased the false-positive rate by almost 50%. Patients with ECG-LVH had approximately 3.5 times the 30-day mortality rate as those without these ECG abnormalities. It appears that for patients with symptoms suggestive of ACS, the presence of ECG-LVH or BBB did not alter the ability of ED clinicians to identify patients with ACS but was associated with a 50% higher false-positive admission rate compared with similar patients without these ECG abnormalities. With a short-term mortality rate 3.5 times that for patients without ECG-LVH, selected patients with ECG-LVH and symptoms suggesting ACS might benefit from hospitalization for further evaluation.

  2. Clinical characteristics and value in early reperfusion therapy for new onset right bundle branch block in patients with acute myocardial infarction

    Science.gov (United States)

    Li, Jingchao; Li, Xiaodong; Dong, Shujuan; Yang, Yapan; Chu, Yingjie

    2018-01-01

    The value of the right bundle branch block (RBBB) in the treatment of acute myocardial infarction remains unclear. Studies on the RBBB may significantly influence the treatment of acute myocardial infarction. A total of 845 patients with acute myocardial infarction who underwent primary coronary angiography at Henan Provincial People's Hospital were analyzed. Higher peak enzyme levels, a higher ratio of Killip ≥II and closer proximal occlusion of infarct-related artery (IRA) were observed in patients with RBBB compared with those without. The ratio of TIMI flow 0/1 of IRA and ratio of received primary percutaneous coronary intervention (PCI) to IRA in the RBBB group were significantly higher compared with those in the left (L) BBB or no BBB groups. The in-hospital major adverse cardiac events (MACE) incidence in the RBBB group was higher compared with that in the no BBB group, but there was no significant difference between the RBBB and LBBB groups. Logistic regression revealed that proximal occlusion and TIMI flow 0/1 of IRA were predictive factors of RBBB. Cox regression analysis identified RBBB [risk ratio (RR), 4.682; P<0.001] and LBBB (RR, 3.687; P<0.001) as independent predictors of in-hospital MACE. The cumulative one-year survival rate in the RBBB group was significantly lower than those in the no BBB group (P<0.05) and the LBBB group (P<0.05). Similar to the guidelines regarding new onset of LBBB, new onset RBBB should be considered as a standard indicator for reperfusion therapy; as RBBB is associated with more severe symptoms, and higher incidents of complete occlusion of IRA and primary PCI treatment compared with LBBB.

  3. Pre-Existing Right Bundle Branch Block Increases Risk for Death After Transcatheter Aortic Valve Replacement With a Balloon-Expandable Valve.

    Science.gov (United States)

    Watanabe, Yusuke; Kozuma, Ken; Hioki, Hirofumi; Kawashima, Hideyuki; Nara, Yugo; Kataoka, Akihisa; Nagura, Fukuko; Nakashima, Makoto; Shirai, Shinichi; Tada, Norio; Araki, Motoharu; Takagi, Kensuke; Yamanaka, Futoshi; Yamamoto, Masanori; Hayashida, Kentaro

    2016-11-14

    The aim of this study was to determine the impact of pre-existing right bundle branch block (RBBB) on clinical outcomes after transcatheter aortic valve replacement (TAVR). The impact of pre-existing RBBB on clinical outcomes after TAVR is unknown. Between October 2013 and August 2015, 749 patients undergoing TAVR using the Edwards SAPIEN XT prosthesis were prospectively enrolled in the OCEAN-TAVI (Optimized Transcatheter Valvular Intervention) registry from 8 Japanese centers. Electrocardiograms were obtained at baseline. After the procedure, follow-up outpatient visits or telephone interviews were conducted at 30 days, 6 months, and yearly. A total of 102 patients (13.6%) had pre-existing RBBB. The incidence of new pacemaker implantation was significantly higher in the RBBB group (17.6% vs. 2.9%; p < 0.01). The Kaplan-Meier analysis revealed that cardiovascular survival probability was significantly lower in the RBBB group than the no-RBBB group (log-rank p < 0.01). Patients with RBBB and without pacemakers were at higher risk for cardiovascular mortality in the early phase after discharge, and patients with RBBB and pacemakers had higher cardiovascular mortality at mid-term follow-up (log-rank p = 0.01). A multivariate Cox regression model indicated that pre-existing RBBB (hazard ratio: 2.59; 95% confidence interval: 1.15 to 5.85; p < 0.01) was an independent predictor of cardiovascular mortality. Patients with RBBB demonstrated an increased risk for cardiovascular mortality after TAVR, and patients with RBBB and without pacemakers were at higher risk for cardiac death early after discharge. Patients with prior RBBB should be carefully monitored after undergoing TAVR. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  4. Comparative long-term outcomes after cardiac resynchronization therapy in right ventricular paced patients versus native wide left bundle branch block patients.

    Science.gov (United States)

    Tayal, Bhupendar; Gorcsan, John; Delgado-Montero, Antonia; Goda, Akiko; Ryo, Keiko; Saba, Samir; Risum, Niels; Sogaard, Peter

    2016-02-01

    The current guidelines do not clearly state when we should upgrade a patient with right ventricular pacing (RVP) to cardiac resynchronization therapy (CRT), although the deleterious effect of chronic RVP has been established with recent trials. The aims of this study were to compare the long-term survival after CRT in patients upgraded from RVP with that in patients with left bundle branch block (LBBB) with QRS duration ≥ 150 ms and to compare the mechanical properties associated with CRT response in these groups. Overall, 135 patients with implanted CRT from a single center (85 (63%) with native wide LBBB and 50 (37%) with RVP) were studied prospectively. Baseline left ventricular typical contraction pattern was determined using speckle tracking echocardiography in the apical 4-chamber view. The predefined end point was death, heart transplantation, or left ventricular assist device implantation over a period of 4 years. Patients with RVP had a significantly favorable long-term outcomes with adjusted hazard ratio of 0.36 (95% confidence interval 0.14-0.96; P = .04). Both groups had ~70% of patients with typical contraction pattern. The absence of typical contraction pattern was associated with a higher risk of an end point with adjusted hazard ratio of 5.43 (95% confidence interval 2.31-12.72; P < .001). In patients with typical contraction pattern, activation of the apical septal segment occurred more frequently in the RVP group and of the base or mid septal segments in the LBBB group. Patients with HF upgraded from RVP have more favorable long-term outcomes after CRT than do native LBBB patients with QRS duration ≥ 150 ms. Contraction pattern assessment can be used to identify potential responders in the RVP group. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  5. New or presumably new left bundle branch block in patients with suspected acute coronary syndrome: Clinical, echocardiographic, and electrocardiographic features from a single-center registry.

    Science.gov (United States)

    Hanna, Elias B; Lathia, Viral N; Ali, Murtuza; Deschamps, Eliana Hanna

    2015-01-01

    In patients with suspected acute coronary syndrome, a new or presumably new left bundle branch block (LBBB) does not always imply ST-segment elevation myocardial infarction (STEMI). We aimed to show the low frequency of STEMI-equivalent in this population and determine the diagnostic value of electrocardiographic and echocardiographic features. From the 387 patients captured by the Louisiana State University code STEMI registry between 2009 and 2012, we examined data on 26 patients with LBBB. These patients were divided into 3 groups according to the final diagnosis: (1) STEMI-equivalent, defined as an acute coronary occlusion on angiography (2 patients), (2) non-ST-segment elevation myocardial infarction (4 patients), and (3) diagnoses other than myocardial infarction (non-MI) (20 patients). Troponin elevation and left ventricular systolic dysfunction were common in all 3 groups (non-significant p-values). Compared with non-MI patients, patients with STEMI-equivalent had a larger degree of ST-segment discordance and T-wave discordance, as assessed by ST/QRS and T/QRS ratios (p<0.001). ST/QRS ratio ≥ 0.2 and T/QRS ratio ≥ 0.5 were sensitive and specific for the diagnosis of STEMI-equivalent in the setting of LBBB. Conversely, absolute values of ST-segment and T-wave discordance were not significantly different between groups. ST-segment concordance was highly specific for the diagnosis of STEMI-equivalent, but had a limited sensitivity. Only a minority of patients with suspected acute coronary syndrome and LBBB have a STEMI-equivalent. Excessive relative discordance of the ST segment or the T wave appears predictive of STEMI-equivalent, but this is only hypothesis-generating considering the small population size. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Among patients with left bundle branch block, T-wave peak to T-wave end time is prolonged in the presence of acute coronary occlusion.

    Science.gov (United States)

    Dodd, Kenneth W; Elm, Kendra D; Dodd, Erin M; Smith, Stephen W

    2017-06-01

    Assessing the effect of myocardial ischemia on ventricular repolarization in the setting of left bundle branch block (LBBB) poses a challenge due to secondary prolongation of the QT interval inherent in LBBB. The T-wave peak to T-wave end (TpTe) interval has been noted to prolong during myocardial ischemia and correct after reperfusion in patients with normal conduction. Here we compare the TpTe intervals of patients with LBBB both with and without complete acute coronary occlusion (ACO). Retrospectively, emergency department patients with LBBB and symptoms of myocardial ischemia were identified both with angiographically-proven ACO and with No-ACO. The longest QT, JT, and TpTe intervals were analyzed. The ACO and No-ACO groups consisted of 33 and 129 patients, respectively. The mean TpTe was longer in ACO (103.6ms [95%CI 98.5-108.7]) compared to No-ACO patients (88.6ms [95%CI 85.3-91.9]) (P<0.0001) and this held true after correction for heart rate. In ACO versus No-ACO, the TpTe also more frequently exceeded prolongation cutoffs of 85ms (30 [90%] versus 69 [54%]) and 100ms (25 [76%] versus 42 [33%]) (P<0.0001 for all). The mean QT, JT, QTc, and JTc intervals were not significantly different between the groups for either the Bazett's or Rautaharju's correction formulas. In patients with LBBB on the ECG, the TpTe is longer and more frequently prolonged in patients with ACO compared to patients without ACO. Future studies of ventricular repolarization in patients with LBBB should include analyses of the TpTe interval. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Mechanical discoordination increases continuously after the onset of left bundle branch block despite constant electrical dyssynchrony in a computational model of cardiac electromechanics and growth

    Science.gov (United States)

    Kerckhoffs, Roy C.P.; Omens, Jeffrey H.; McCulloch, Andrew D.

    2012-01-01

    Aims To test whether a functional growth law leads to asymmetric hypertrophy and associated changes in global and regional cardiac function when integrated with a computational model of left bundle branch block (LBBB). Methods and results In recent studies, we proposed that cardiac myocytes grow longer when a threshold of maximum fibre strain is exceeded and grow thicker when the smallest maximum principal strain in the cellular cross-sectional plane exceeds a threshold. A non-linear cardiovascular model of the beating canine ventricles was combined with the cellular growth law. After inducing LBBB, the ventricles were allowed to adapt in shape over time in response to mechanical stimuli. When subjected to electrical dyssynchrony, the combined model of ventricular electromechanics, haemodynamics, and growth led to asymmetric hypertrophy with a faster increase of wall mass in the left ventricular (LV) free wall (FW) than the septum, increased LV end-diastolic and end-systolic volumes, and decreased LV ejection fraction. Systolic LV pressure decreased during the acute phase of LBBB and increased at later stages. The relative changes of these parameters were similar to those obtained experimentally. Most of the dilation was due to radial and axial fibre growth, and hence altered shape of the LVFW. Conclusion Our previously proposed growth law reproduced measured dyssynchronously induced asymmetric hypertrophy and the associated functional changes, when combined with a computational model of the LBBB heart. The onset of LBBB leads to a step increase in LV mechanical discoordination that continues to increase as the heart remodels despite the constant electrical dyssynchrony. PMID:23104917

  8. Prognostic usefulness of contemporary stress echocardiography in patients with left bundle branch block and impact of contrast use in improving prediction of outcome.

    Science.gov (United States)

    Vamvakidou, Anastasia; Karogiannis, Nikos; Tzalamouras, Vasilis; Parsons, Guy; Young, Grace; Gurunathan, Sothinathan; Senior, Roxy

    2017-04-01

    Patients with symptomatic left bundle branch block (LBBB) may have myocardial ischaemia due to both coronary artery disease and/or cardiomyopathy (microcirculatory abnormalities) and may have concomitant left ventricular (LV) dysfunction. We aimed to assess the feasibility and prognostic value of contemporary stress echocardiography (SE), which can uncover both pathophysiologies in LBBB patients in routine clinical practice, and also aimed to assess the additive value of contrast SE. Accordingly, 190 consecutive patients (age 70.5 ± 11.3 years, LV ejection fraction = 50.1 ± 10%) with symptomatic LBBB who underwent SE over 6 years were assessed, of which 142 (75%) underwent contrast SE and 176 (92.6%) had diagnostic SE. Inducible ischaemia was present in 25 (14.2%) patients. During follow-up (35.4 ± 20.2 months) there were 32 deaths (18%) and 18 (10.2%) first cardiovascular (CV) events (acute myocardial infarction/mortality) in the 176 patients with diagnostic studies. Wall thickening score index at peak stress (WTSIpeak), which measures combined LV function and inducible ischaemia, was an independent predictor of mortality (HR = 3.78, 95% CI = 1.39-10.31, P = 0.01) and CV events (HR = 3.96, 95% CI = 1.1-14.3, P = 0.036). An abnormal SE (myocardial ischaemia and/or abnormal LV function) predicted an almost three-fold increase in all-cause mortality and CV events compared with normal SE. Amongst the confounders affecting assessment of wall thickening in LBBB and conventional prognostic variables, use of contrast was an independent predictor (P = 0.034) of WTSI1.16 (optimal predictor of mortality/CV outcome). SE in patients with LBBB demonstrated high feasibility and the combination of LV systolic function and myocardial ischaemia provided important prognostic information. Contrast-enhanced SE improved the prediction of outcome.

  9. Septal and Anterior Reverse Mismatch of Myocardial Perfusion and Metabolism in Patients With Coronary Artery Disease and Left Bundle Branch Block

    Science.gov (United States)

    Wang, Jian-Guang; Fang, Wei; Yang, Min-Fu; Tian, Yue-Qin; Zhang, Xiao-Li; Shen, Rui; Sun, Xiao-Xin; Guo, Feng; Wang, Dao-Yu; He, Zuo-Xiang

    2015-01-01

    Abstract The effects of left bundle branch block (LBBB) on left ventricular myocardial metabolism have not been well investigated. This study evaluated these effects in patients with coronary artery disease (CAD). Sixty-five CAD patients with complete LBBB (mean age, 61.8 ± 9.7 years) and 65 without LBBB (mean age, 59.9 ± 8.4 years) underwent single photon emission computed tomography, positron emission tomography, and contrast coronary angiography. The relationship between myocardial perfusion and metabolism and reverse mismatch score, and that between QRS length and reverse mismatch score and wall motion score were evaluated. The incidence of left ventricular septum and anterior wall reverse mismatching between the two groups was significantly different (P < 0.001 and P = 0.002, respectively). The incidences of normal myocardial perfusion and metabolism in the left ventricular lateral and inferior walls were also significantly different between the two groups (P < 0.001 and P < 0.001, respectively). The incidence of septal reverse mismatching in patients with mild to moderate perfusion was significantly higher among those with LBBB than among those without LBBB (P < 0.001). In CAD patients with LBBB, septal reverse mismatching was significantly more common among those with mild to moderate perfusion than among those with severe perfusion defects (P = 0.002). The correlation between the septal reverse mismatch score and QRS length was significant (P = 0.026). In patients with CAD and LBBB, septal and anterior reverse mismatching of myocardial perfusion and metabolism was frequently present; the septal reverse mismatch score negatively correlated with the QRS interval. PMID:25997045

  10. Genetic variation at the human connexin 43 locus but not at the connexin 40 locus is associated with left bundle branch block

    Science.gov (United States)

    Ladenvall, Per; Andersson, Björn; Dellborg, Mikael; Hansson, Per-Olof; Eriksson, Henry; Thelle, Dag; Eriksson, Peter

    2015-01-01

    Background Bundle branch block (BBB) has been regarded as a disease of the conduction system, but occurs in mice lacking connexin 40 (expressed in atria, proximal conduction system) or connexin 43 (expressed in Purkinje cells, cardiomyocytes). Objective The aim of this paper is to explore whether BBB is heritable, and whether polymorphisms at connexin 40 and connexin 43 loci are associated with BBB. Methods To assess BBB heritability, we screened descendants of men with BBB in the population cohort ‘The Study of Men Born 1913’. DNA samples from 80-year-old men with extreme QRS-duration phenotypes were used to search for polymorphisms at connexin 40 and 43 loci. Associations between identified polymorphisms and BBB were evaluated in an independent cohort (INTERGENE). Results Seventy-seven men from ‘The Study of Men Born 1913’ with BBB had 116 descendants. Among the 76 participating descendants, 2 sons (6.4%) had BBB at 54 years of age. At the same age, 0.9% of men born in 1913 had BBB. We identified 6 single nucleotide polymorphisms (SNPs) in connexin 40 and 1 polymorphism in connexin 43. In the INTERGENE cohort, the connexin 43 polymorphism was associated with left BBB (LBBB) (4 of 35 LBBB vs 16 of 232 without BBB, χ2=7.4, p=0.03), but not with right BBB (RBBB) or overall BBB. None of the connexin 40 SNPs or haplotypes were associated with LBBB or RBBB. Conclusions These findings indicate that conduction by connexin 43 within the ventricular muscle distal to the specialised conduction system may be important for LBBB development. PMID:25893100

  11. A U-shaped type II contraction pattern in patients with strict left bundle branch block predicts super-response to cardiac resynchronization therapy.

    Science.gov (United States)

    Jackson, Tom; Sohal, Manav; Chen, Zhong; Child, Nicholas; Sammut, Eva; Behar, Jonathan; Claridge, Simon; Carr-White, Gerald; Razavi, Reza; Rinaldi, Christopher Aldo

    2014-10-01

    New criteria to define strict left bundle branch block (LBBB) on the basis of pathophysiological principles predict response to cardiac resynchronization therapy (CRT). Heterogeneous activation and contraction patterns have been identified in patients with classical LBBB. Cardiac magnetic resonance (CMR) imaging has demonstrated that a U-shaped (type II) contraction predicts reverse remodeling post-CRT. A homogeneous spread of (type I) contraction is less predictive. The purpose of this study was to investigate contraction patterns among patients with strict LBBB and to test whether a type II contraction pattern better predicts CRT response and super-response. Thirty-seven patients with strict LBBB (QRS duration ≥140 ms for men and ≥130 ms for women with mid-QRS notching or slurring in ≥2 contiguous leads) underwent cine CMR imaging pre-CRT with an analysis of their contraction patterns by using endocardial contour tracking software. Patients were evaluated for reverse remodeling 6 months postimplantation. Nineteen patients (51%) had a type II contraction pattern. A total of 25 patients (68%) of the cohort reverse remodeled. In the type II contraction group, all 19 patients (100%) reverse remodeled as compared with 6 patients (33%) in the type I contraction group (P < .01). Super-response was achieved in 21 patients (57%) of the total cohort: 5 patients with a type I contraction pattern (28%) and 16 patients with a type II contraction pattern (84%) (P < .01). Patients with strict LBBB who are guideline indicated for CRT have heterogeneous contraction patterns derived from cine CMR. A type II contraction pattern is strongly predictive for reverse remodeling and super-response. This questions whether strict LBBB criteria alone are sufficient to reliably predict a positive response to CRT. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  12. Detailed analysis of ventricular activation sequences during right ventricular apical pacing and left bundle branch block and the potential implications for cardiac resynchronization therapy.

    Science.gov (United States)

    Eschalier, Romain; Ploux, Sylvain; Lumens, Joost; Whinnett, Zachary; Varma, Niraj; Meillet, Valentin; Ritter, Philippe; Jaïs, Pierre; Haïssaguerre, Michel; Bordachar, Pierre

    2015-01-01

    Left bundle branch block (LBBB) leads to prolonged left ventricular (LV) total activation time (TAT) and ventricular electrical uncoupling (VEU; mean LV activation time minus mean right ventricular [RV] activation time); both have been shown to be preferential targets for cardiac resynchronization therapy (CRT). Whether right ventricular apical pacing (RVAP) produces similar ventricular activation patterns has not been well studied. The purpose of this study was to compare electrical ventricular activation patterns during RVAP and LBBB. We performed ECG mapping during sinus rhythm, RVAP, and CRT in 24 patients with LBBB. We observed differences in the electrical activation pattern with RVAP compared to LBBB. During LBBB, RV activation occurred rapidly; in contrast, RV activation was prolonged during RVAP (46 ± 21 ms vs 69 ± 17 ms, P <.001). There was no significant difference in LVTAT; however, differences in conduction pattern were observed. During LBBB, LV activation was circumferential, whereas with RVAP, LV activation proceeded from apex to base. Differences in the number, size, and orientation of lines of slow conduction also were observed. With LBBB, VEU was nearly twice as long as during RVAP (73 ± 12 ms vs 38 ± 21 ms, P <.001). CRT resulted in a greater reduction in VEU relative to LBBB activation (P <.001). RVAP produces significant differences in ventricular activation characteristics compared to LBBB. Significantly less VEU occurs with RVAP, and as a result CRT produces a smaller relative reduction in VEU. This may explain the finding that CRT appears to be more effective in patients with LBBB than in those who were upgraded because of high percentages of RV pacing. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  13. Accuracy of non-invasive techniques for diagnosis of coronary artery disease and prediction of cardiac events in patients with left bundle branch block: a meta-analysis

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    Biagini, Elena [Thoraxcenter Erasmus MC, Department of Cardiology, Rotterdam (Netherlands); University of Bologna, Institute of Cardiology, S.Orsola-Malpighi Hospital, Bologna (Italy); Shaw, Leslee J. [Cedars-Sinai Medical Center, Los Angeles, CA (United States); Poldermans, Don; Schinkel, Arend F.L.; Rizzello, Vittoria [Thoraxcenter Erasmus MC, Department of Cardiology, Rotterdam (Netherlands); Elhendy, Abdou [University of Nebraska Medical Center, Omaha, NE (United States); Rapezzi, Claudio [University of Bologna, Institute of Cardiology, S.Orsola-Malpighi Hospital, Bologna (Italy); Bax, Jeroen J. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands)

    2006-12-15

    Non-invasive evaluation of coronary artery disease (CAD) in patients with left bundle branch block (LBBB) has limitations inherent to different tests, and the relative merits of these tests are unclear. This meta-analysis assessed the accuracy of the frequently used non-invasive techniques, including exercise electrocardiography (ECG), myocardial perfusion imaging (MPI) and stress echocardiography (SE), for detection of CAD and prediction of cardiac events in patients with LBBB. A review was conducted of all reports on detection of CAD and prediction of cardiac events in patients with LBBB (published between January 1970 and December 2004), and revealed 55 diagnostic and nine prognostic reports with sufficient details to calculate test accuracy. Weighted (by sample size) sensitivity and specificity were calculated. Summary relative risk ratios (95% confidence intervals) were calculated. Overall sensitivity was higher for exercise ECG and (quantitatively analysed) MPI than for SE (83.4% and 88.5% versus 74.6% respectively, p<0.0001). SE had a higher specificity (88.7%) than MPI (41.2%) and exercise ECG (60.1%) (p<0.0001). Based on analysis of eight reports, the relative risk of cardiac death or myocardial infarction in patients with an abnormal SE and MPI was elevated more than sevenfold, but it did not differ by imaging modality (p=0.9). Meta-analysis of non-invasive CAD assessment in LBBB patients revealed that exercise ECG and MPI had the highest sensitivity, while SE had the highest specificity. The prognostic accuracy of MPI and SE appeared similar. (orig.)

  14. Left bundle branch block with acute thrombotic occlusion is associated with increased myocardial jeopardy score and poor clinical outcomes in primary percutaneous coronary intervention activations.

    Science.gov (United States)

    Brown, Adam J; Hoole, Stephen P; McCormick, Liam M; Malone-Lee, Matt; Cacciottolo, Paul J; Schofield, Peter M; West, Nick E J

    2013-06-01

    To assess the utility of left bundle branch block (LBBB) as an activation criterion for primary percutaneous coronary intervention (PPCI). Retrospective observational cohort study. Single UK heart attack centre. Consecutive patients referred for PPCI September 2008-December 2011 (n=2192). Demographic and outcome data were obtained by review of case notes, angiograms and interrogation of local/national databases. Angiographic culprit lesion assessment defined appropriate and inappropriate activations. Patients outcomes were assessed by Major adverse cardiac events (MACE), defined as a composite of mortality and unplanned revascularisation at 1-year. LBBB-activation occurred in 120 patients (5.5%), of whom 21 (17.5%) had acute coronary occlusion angiographically, and were adjudicated appropriately. Compared with appropriate activations for ST segment elevation, appropriate LBBB-activations were older (71.0 ± 9.6 vs 64.2 ± 12.4 years, p=0.01) and more likely to be in cardiogenic shock (19.0% vs 4.3%, pmyocardium at-risk was higher in appropriate LBBB-activations (culprit jeopardy score median 4, IQR 2-6 vs 2, 2-4, p=0.02). Final diagnoses for LBBB-activations were acute coronary syndrome (39.2%), non-acute coronary syndrome cardiac chest pain (33.3%) and non-cardiac chest pain (27.5%). In appropriate LBBB-activations 1-year mortality and MACE were higher (23.8% vs 6.6%, p=0.002 and 28.6% vs 10.5%, p=0.007, respectively). Our data suggests that despite its poor specificity for identifying acute coronary occlusion, LBBB should at the present time remain an activation criterion for PPCI and such patients should continue to be transferred to heart attack centres for assessment and treatment.

  15. Patients with left bundle branch block and left axis deviation show a specific left ventricular asynchrony pattern: Implications for left ventricular lead placement during CRT implantation.

    Science.gov (United States)

    Sciarra, Luigi; Golia, Paolo; Palamà, Zefferino; Scarà, Antonio; De Ruvo, Ermenegildo; Borrelli, Alessio; Martino, Anna Maria; Minati, Monia; Fagagnini, Alessandro; Tota, Claudia; De Luca, Lucia; Grieco, Domenico; Delise, Pietro; Calò, Leonardo

    2017-10-21

    Left bundle branch block (LBBB) and left axis deviation (LAD) patients may have poor response to resynchronization therapy (CRT). We sought to assess if LBBB and LAD patients show a specific pattern of mechanical asynchrony. CRT candidates with non-ischemic cardiomyopathy and LBBB were categorized as having normal QRS axis (within -30° and +90°) or LAD (within -30° and -90°). Patients underwent tissue Doppler imaging (TDI) to measure time interval between onset of QRS complex and peak systolic velocity in ejection period (Q-peak) at basal segments of septal, inferior, lateral and anterior walls, as expression of local timing of mechanical activation. Thirty patients (mean age 70.6years; 19 males) were included. Mean left ventricular ejection fraction was 0.28±0.06. Mean QRS duration was 172.5±13.9ms. Fifteen patients showed LBBB with LAD (QRS duration 173±14; EF 0.27±0.06). The other 15 patients had LBBB with a normal QRS axis (QRS duration 172±14; EF 0.29±0.05). Among patients with LAD, Q-peak interval was significantly longer at the anterior wall in comparison to each other walls (septal 201±46ms, inferior 242±58ms, lateral 267±45ms, anterior 302±50ms; p<0.0001). Conversely, in patients without LAD Q-peak interval was longer at lateral wall, when compared to each other (septal 228±65ms, inferior 250±64ms, lateral 328±98ms, anterior 291±86ms; p<0.0001). Patients with heart failure, presenting LBBB and LAD, show a specific pattern of ventricular asynchrony, with latest activation at anterior wall. This finding could affect target vessel selection during CRT procedures in these patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Prolongation of QRS duration and axis deviation in the right bundle branch block are not markers for left ventricular systolic dysfunction.

    Science.gov (United States)

    Uyguanco, Eric R; Mirandi, Anthony; Qureshi, Ghazanfar; Lazar, Jason; Chhabra, Amit; Kassotis, John

    2010-01-01

    Right bundle branch block (RBBB) is not commonly associated with structural heart disease and left ventricular (LV) systolic dysfunction. The purpose of the present study was to determine whether the QRS duration and degree of right axis deviation (RAD) or left axis deviation (LAD) in patients with RBBB predicted a subset of patients with significant LV systolic dysfunction. In the present prospective study, 75 of 200 consecutive patients with RBBB had their ejection fraction (EF) evaluated by echocardiography. The relationship among QRS duration, axis and EF was derived. There were no significant differences in sex and EF among the patients with a normal axis, RAD or LAD. The EFs of patients with a normal axis (n=27), RAD (n=15) and LAD (n=33) were 52±15%, 49±14% and 46±17%, respectively (P=0.35). The mean EF (46±16%) of patients with a QRS duration of 150 ms or greater (n=53) was not significantly different from the mean EF (49±18%) of patients with a QRS duration of less than 150 ms (n=22) (P=0.54). For patients with a QRS of 120 ms or greater and less than 150 ms (n=22), QRS of 150 ms or greater and 180 ms or less (n=48), and QRS of greater than 180 ms (n=5), the mean EFs were 49±18%, 47±16% and 44±7%, respectively (P=0.78). There was no significant correlation between QRS duration and EF in all patients (r=0.03, P=0.83), EF and RAD (r=0.38, P=0.16) or EF and LAD (r=0.26, P=0.14). In patients with RBBB, the QRS duration and axis do not have a significant relationship with EF. Furthermore, prolongation of the QRS duration (150 ms or greater) in the presence of RBBB is not a marker of significant LV systolic dysfunction.

  17. Bundle branch reentry: A rare mechanism of ventricular tachycardia in endomyocardial fibrosis, without ventricular dilation.

    Science.gov (United States)

    Prabhu, Mukund A; Prasad, B V Srinivas; Thajudeen, Anees; Namboodiri, Narayanan

    2016-09-01

    Bundle branch reentry as a mechanism of ventricular tachycardia (VT) in endomyocardial fibrosis (EMF) is not described. A 52-year-old woman with left ventricular (LV) EMF had VT needing cardioversion. She had mitral regurgitation and left bundle branch block, but no LV dilation or heart failure. During electrophysiological study, clinical VT could be easily induced, and it was confirmed to be bundle branch reentrant VT (BBRVT). She was treated with ablation of the right bundle branch. BBRVT can occur in EMF even without cardiac dilatation. Its recognition is important, as radiofrequency ablation can be curative. Copyright © 2016 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  18. Impact of new-onset persistent left bundle branch block on late clinical outcomes in patients undergoing transcatheter aortic valve implantation with a balloon-expandable valve.

    Science.gov (United States)

    Urena, Marina; Webb, John G; Cheema, Asim; Serra, Vicenç; Toggweiler, Stefan; Barbanti, Marco; Cheung, Anson; Ye, Jian; Dumont, Eric; DeLarochellière, Robert; Doyle, Daniel; Al Lawati, Hatim A; Peterson, Marc; Chisholm, Robert; Igual, Albert; Ribeiro, Henrique Barbosa; Nombela-Franco, Luis; Philippon, François; Garcia Del Blanco, Bruno; Rodés-Cabau, Josep

    2014-02-01

    The aim of this study was to determine the impact of new-onset persistent left bundle branch block (NOP-LBBB) on late outcomes after transcatheter aortic valve implantation (TAVI). The impact of NOP-LBBB after TAVI remains controversial. A total of 668 consecutive patients who underwent TAVI with a balloon-expandable valve without pre-existing LBBB or permanent pacemaker implantation (PPI) were included. Electrocardiograms were obtained at baseline, immediately after the procedure, and daily until hospital discharge. Patients were followed at 1, 6, and 12 months and yearly thereafter. New-onset LBBB occurred in 128 patients (19.2%) immediately after TAVI and persisted at hospital discharge in 79 patients (11.8%). At a median follow-up of 13 months (range 3 to 27 months), there were no differences in mortality rate between the NOP-LBBB and no NOP-LBBB groups (27.8% vs. 28.4%; adjusted-hazard ratio: 0.87 [95% confidence interval (CI): 0.55 to 1.37]; p = 0.54). There were no differences between groups regarding cardiovascular mortality (p = 0.82), sudden death (p = 0.87), rehospitalizations for all causes (p = 0.11), or heart failure (p = 0.55). NOP-LBBB was the only factor associated with an increased rate of PPI during the follow-up period (13.9% vs. 3.0%; hazard ratio: 4.29 [95% CI: 2.03 to 9.07], p < 0.001. NOP-LBBB was also associated with a lack of left ventricular ejection fraction improvement and poorer New York Heart Association functional class at follow-up (p < 0.02 for both). NOP-LBBB occurred in ∼1 of 10 patients who had undergone TAVI with a balloon-expandable valve. NOP-LBBB was associated with a higher rate of PPI, a lack of improvement in left ventricular ejection fraction, and a poorer functional status, but did not increase the risk of global or cardiovascular mortality or rehospitalizations at 1-year follow-up. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  19. Quantitative Analysis of Electro-Anatomical Maps: Application to an Experimental Model of Left Bundle Branch Block/Cardiac Resynchronization Therapy

    Science.gov (United States)

    Duchateau, Nicolas; Kostantyn Butakov, Constantine Butakoff; Andreu, David; Fernández-Armenta, Juan; Bijnens, Bart; Berruezo, Antonio; Sitges, Marta; Camara, Oscar

    2017-01-01

    Electro-anatomical maps (EAMs) are commonly acquired in clinical routine for guiding ablation therapies. They provide voltage and activation time information on a 3-D anatomical mesh representation, making them useful for analyzing the electrical activation patterns in specific pathologies. However, the variability between the different acquisitions and anatomies hampers the comparison between different maps. This paper presents two contributions for the analysis of electrical patterns in EAM data from biventricular surfaces of cardiac chambers. The first contribution is an integrated automatic 2-D disk representation (2-D bull’s eye plot) of the left ventricle (LV) and right ventricle (RV) obtained with a quasi-conformal mapping from the 3-D EAM meshes, that allows an analysis of cardiac resynchronization therapy (CRT) lead positioning, interpretation of global (total activation time), and local indices (local activation time (LAT), surrogates of conduction velocity, inter-ventricular, and transmural delays) that characterize changes in the electrical activation pattern. The second contribution is a set of indices derived from the electrical activation: speed maps, computed from LAT values, to study the electrical wave propagation, and histograms of isochrones to analyze regional electrical heterogeneities in the ventricles. We have applied the proposed methods to look for the underlying physiological mechanisms of left bundle branch block (LBBB) and CRT, with the goal of optimizing the therapy by improving CRT response. To better illustrate the benefits of the proposed tools, we created a set of synthetically generated and fully controlled activation patterns, where the proposed representation and indices were validated. Then, the proposed analysis tools are used to analyze EAM data from an experimental swine model of induced LBBB with an implanted CRT device. We have analyzed and compared the electrical activation patterns at baseline, LBBB, and CRT stages in

  20. Idiopathic left ventricular tachycardia with a right bundle branch block morphology and left axis deviation ("Belhassen type"): results of radiofrequency ablation in 18 patients.

    Science.gov (United States)

    Topilski, Ian; Glick, Aharon; Belhassen, Bernard

    2004-04-01

    Idiopathic left ventricular tachycardia with a right bundle branch block configuration and left axis deviation, first described by Belhassen et al., is a rare electrocardiographic-electrophysiologic entity. Radiofrequency catheter ablation has been proposed as a good therapeutic option, but the best criteria for determining the optimal site of ablation are still under debate. To report the clinical features, electrophysiologic characteristics, results of RFA, and long-term outcome in 18 patients with "Belhassen's VT" treated in our laboratory during the last 10 years, stressing the best electrophysiologic criteria for determining the optimal site of ablation. Eighteen consecutive patients with this specific VT underwent RFA in our laboratory during the last 10 years. RFA was acutely successful in 17 patients after one or two procedures (15 and 2 patients, respectively) using 4.1 +/- 2.2 RF pulses. The putative ablation sites were defined by good pace-mapping (3 patients), earliest recorded Purkinje spike prior to the QRS onset during VT or sinus rhythm (6 patients), earliest endocardial activation during VT (1 patient), and diastolic potential preceding the Purkinje spike during VT and/or late diastolic potential in sinus rhythm (7 patients). In the patients with a definite successful ablation, the ratio of successful to unsuccessful radiofrequency pulse delivery to the diastolic potential site was compared to that of other methods. The ratio of successful RFA at the diastolic potential site (5:8) was higher than in the other methods (8:31) and the difference was statistically significant (P = 0.05). Successful ablation sites were more basal when the diastolic potential site was chosen. The results of the present study confirm the high success rate and safety of RFA using conventional techniques in the management of "Belhassen VT," suggesting that this procedure can be used as a first-line therapy. Ablating at a site demonstrating a late diastolic potential is at

  1. Discontinuous conduction in mouse bundle branches is caused by bundle-branch architecture

    NARCIS (Netherlands)

    van Veen, Toon A. B.; van Rijen, Harold V. M.; van Kempen, Marjan J. A.; Miquerol, Lucile; Opthof, Tobias; Gros, Daniel; Vos, Marc A.; Jongsma, Habo J.; de Bakker, Jacques M. T.

    2005-01-01

    Background - Recordings of the electrical activity of mouse bundle branches ( BBs) suggest reduced conduction velocity ( CV) in the midseptal compared with the proximal part of the BB. The present study was performed to elucidate the mechanism responsible for this slowing of conduction. Methods and

  2. Relation of QRS Duration to Clinical Benefit of Cardiac Resynchronization Therapy in Mild Heart Failure Patients Without Left Bundle Branch Block: The Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy Substudy.

    Science.gov (United States)

    Biton, Yitschak; Kutyifa, Valentina; Cygankiewicz, Iwona; Goldenberg, Ilan; Klein, Helmut; McNitt, Scott; Polonsky, Bronislava; Ruwald, Anne Christine; Ruwald, Martin H; Moss, Arthur J; Zareba, Wojciech

    2016-02-01

    There are conflicting data regarding the efficacy of cardiac resynchronization therapy (CRT) in patients with heart failure (HF) and without left bundle branch block. We evaluated the long-term clinical outcomes of 537 non-left bundle branch block patients with mild HF enrolled in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) study by QRS duration or morphology further stratified by PR interval. At 7 years of follow-up, the cumulative probability of HF hospitalization or death was 45% versus 56% among patients randomized to implantable cardioverter-defibrillator and CRT with defibrillator (CRT-D), respectively (P=0.209). Multivariable-adjusted subgroup analysis by QRS duration showed that patients from the lower quartile QRS duration group (≤ 134 ms) experienced 2.4-fold (P=0.015) increased risk for HF hospitalization or death with CRT-D versus implantable cardioverter-defibrillator only therapy, whereas the effect of CRT-D in patients from the upper quartiles group (QRS>134 ms) was neutral (hazard ratio [HR] =0.97, P=0.86; P value for interaction =0.024). In a second analysis incorporating PR interval, patients with prolonged QRS (>134 ms) and prolonged PR (>230 ms) were protected with CRT-D (HR=0.31, P=0.003), whereas the association was neutral with prolonged QRS (>134 ms) and shorter PR (≤ 230 ms;, HR=1.19, P=0.386; P value for interaction =0.002). The effect was neutral, regardless of morphology, right bundle branch block (HR=1.01, P=0.975), and intraventricular conduction delay (HR=1.31, P=0.172). Overall, patients with mild HF but without left bundle branch block morphology did not derive clinical benefit with CRT-D during long-term follow-up. Relatively shorter QRS was associated with a significantly increased risk with CRT-D relative to implantable cardioverter-defibrillator -only. URL: http://www.clinicaltrials.gov. Unique identifiers: NCT00180271, NCT01294449, and NCT02060110. © 2016

  3. Application of prophylactic gel-pads for transcutaneous pacing in patients with complete right bundle-branch block with axis deviation when surgical procedures are performed: 10-year experience from a single Japanese university hospital.

    Science.gov (United States)

    Okamoto, Aki; Inoue, Satoki; Tanaka, Yu; Kawaguchi, Masahiko; Furuya, Hitoshi

    2009-01-01

    This retrospective study aimed to determine whether prophylactic transcutaneous pacing is required for patients with complete right bundle-branch block (CRBBB) and axis deviation (AD), so-called bifascicular block, when surgical procedures are performed under general or local anesthesia. The authors reviewed 34 063 anesthesia cases that took place at Nara Medical University Hospital during a 10-year period (1996-2005). The anesthesia records of all identified patients having CRBBB or bifascicular block were retrospectively reviewed and the incidence of block progression to complete heart block or bradycardia requiring temporary transcutaneous pacing served as the primary endpoint. As a secondary endpoint, the incidence of block progression to complete heart block or bradycardia requiring only medical treatment was checked. Seventy of the 34 063 patients (0.2%) had CRBBB with AD. Only 1 patient with CRBBB with left AD, who underwent on-pump aorto-coronary bypass grafting surgery, developed complete heart block at the resumption of heartbeat. None of the other 69 patients, except for this cardiac case, developed complete heart block during surgery. Based on this analysis of 70 cases, prophylactic gel-pad electrode application in patients with CRBBB and AD does not appear to be necessary during surgical procedures.

  4. GPU Parallel Bundle Block Adjustment

    Directory of Open Access Journals (Sweden)

    ZHENG Maoteng

    2017-09-01

    Full Text Available To deal with massive data in photogrammetry, we introduce the GPU parallel computing technology. The preconditioned conjugate gradient and inexact Newton method are also applied to decrease the iteration times while solving the normal equation. A brand new workflow of bundle adjustment is developed to utilize GPU parallel computing technology. Our method can avoid the storage and inversion of the big normal matrix, and compute the normal matrix in real time. The proposed method can not only largely decrease the memory requirement of normal matrix, but also largely improve the efficiency of bundle adjustment. It also achieves the same accuracy as the conventional method. Preliminary experiment results show that the bundle adjustment of a dataset with about 4500 images and 9 million image points can be done in only 1.5 minutes while achieving sub-pixel accuracy.

  5. Genetics Home Reference: progressive familial heart block

    Science.gov (United States)

    ... in my area? Other Names for This Condition bundle branch block HBBD hereditary bundle branch defect hereditary bundle branch ... defect TeensHealth from Nemours: Arrhythmias Texas Heart Institute: Bundle Branch Block Patient Support and Advocacy Resources (3 links) American ...

  6. Relationship between two-dimensional speckle-tracking septal strain and response to cardiac resynchronization therapy in patients with left ventricular dysfunction and left bundle branch block: a prospective pilot study.

    Science.gov (United States)

    Maréchaux, Sylvestre; Guiot, Aurélie; Castel, Anne Laure; Guyomar, Yves; Semichon, Marc; Delelis, François; Heuls, Sebastien; Ennezat, Pierre-Vladimir; Graux, Pierre; Tribouilloy, Christophe

    2014-05-01

    Previous studies have demonstrated variable patterns of longitudinal septal deformation in patients with left ventricular (LV) dysfunction and left bundle branch block. This prospective single center study was designed to assess the relationship between septal deformation patterns obtained by two-dimensional speckle-tracking echocardiography and response to cardiac resynchronization therapy (CRT). One hundred one patients with New York Heart Association class II to IV heart failure, LV ejection fractions ≤ 35%, and left bundle branch block underwent echocardiography before CRT. Longitudinal two-dimensional speckle-tracking strain analysis in the apical four-chamber view identified three patterns: double-peaked systolic shortening (pattern 1), early pre-ejection shortening peak followed by prominent systolic stretch (pattern 2), and pseudonormal shortening with a late systolic shortening peak and less pronounced end-systolic stretch (pattern 3). CRT response was defined as a relative reduction in LV end-systolic volume of ≥ 15% at 9-month follow-up. CRT super-response was defined as an absolute LV ejection fraction of ≥ 50% associated with a relative reduction in LV end-systolic volume of ≥ 15% and an improvement in New York Heart Association functional class. Cardiac death or hospitalization for heart failure during follow-up was systematically investigated. Ninety-two percent of patients with pattern 1 or 2 were responders to CRT compared with 59% with pattern 3 (P < .0001). Thirty-six percent of patients with pattern 1 were super-responders compared with 15% of those with pattern 2 and 12% of those with pattern 3 (P = .037). The improvement in LV volumes, LV ejection fraction, and global longitudinal strain after CRT was better in patients with pattern 1 or 2 compared with those with pattern 3 (P < .0001 for all). Eighteen-month outcomes were excellent in patients with pattern 1 or 2, with event-free survival of 95 ± 3% compared with 75 ± 7% in patients

  7. A Wide QRS/T Angle in Bundle Branch Blocks is Associated with Increased Risk for Coronary Heart Disease and All-cause Mortality in the Atherosclerosis Risk in Communities (ARIC) Study

    Science.gov (United States)

    Zhang, Zhu-ming; Rautaharju, Pentti M.; Prineas, Ronald J.; Whitsel, Eric A; Tereshchenko, Larisa; Soliman, Elsayed Z.

    2015-01-01

    BACKGROUND — Repolarization abnormality in bundle branch blocks (BBB) is traditionally ignored. This study evaluated the prognostic value of QRS/T angle for mortality in the presence and absence of BBB. METHODS and RESULTS — Total 15,408 participants (mean age 54 years, 55.2% women, 26.9% blacks, 2.8% with BBB) were from the Arteriosclerosis Risk in Communities Study. Sex stratified Cox regression models were used to compute hazard ratios (HR) with 95% confidence intervals (CI) for coronary heart disease (CHD) and all-cause mortality for wide spatial QRS/T angle with and without BBB including right BBB (RBBB), left BBB (LBBB) and indetermined-type ventricular conduction defect (IVCD) and RBBB combined with left anterior fascicular block. During a median 22-years follow-up, 4,767 deaths occurred, 728 of them CHD deaths. Using the No-BBB with QRS/T angle below median value as gender-specific reference groups, the mortality risk increase was significant for both women and men with No-BBB and QRS/T angle above the median value. In the pooled ICVD/LBBB group, the risk for CHD death was increased 15.9-fold in women and 6.04 fold in men, and for all-cause deaths 3.01-fold in women and 1.84-fold in men. However, the mortality risk in isolated RBBB group was only significant increase in women but not in men. CONCLUSION — A wide spatial QRS/T angle in BBB is associated with increased risk for CHD and all-cause mortality over and above the predictive value for BBB alone. The risk for women is as high as or higher than that in men. PMID:25959262

  8. Prognosis assessment of persistent left bundle branch block after TAVI by an electrophysiological and remote monitoring risk-adapted algorithm: rationale and design of the multicentre LBBB-TAVI Study.

    Science.gov (United States)

    Massoullié, Grégoire; Bordachar, Pierre; Irles, Didier; Caussin, Christophe; Da Costa, Antoine; Defaye, Pascal; Jean, Frédéric; Mechulan, Alexis; Mondoly, Pierre; Souteyrand, Géraud; Pereira, Bruno; Ploux, Sylvain; Eschalier, Romain

    2016-10-26

    Percutaneous aortic valve replacement (transcatheter aortic valve implantation (TAVI)) notably increases the likelihood of the appearance of a complete left bundle branch block (LBBB) by direct lesion of the LBB of His. This block can lead to high-grade atrioventricular conduction disturbances responsible for a poorer prognosis. The management of this complication remains controversial. The screening of LBBB after TAVI persisting for more than 24 hours will be conducted by surface ECG. Stratification will be performed by post-TAVI intracardiac electrophysiological study. Patients at high risk of conduction disturbances (≥70 ms His-ventricle interval (HV) or presence of infra-Hisian block) will be implanted with a pacemaker enabling the recording of disturbance episodes. Those at lower risk (HV <70 ms) will be implanted with a loop recorder device with remote monitoring of cardiovascular implantable electronic devices (CIEDs). Clinical, ECG and implanted device follow-up will also be performed at 3, 6 and 12 months. The primary objective is to assess the efficacy and safety of a decisional algorithm based on electrophysiological study and remote monitoring of CIEDs in the prediction of high-grade conduction disturbances in patients with LBBB after TAVI. The primary end point is to compare the incidence (rate and time to onset) of high-grade conduction disturbances in patients with LBBB after TAVI between the two groups at 12 months. Given the proportion of high-grade conduction disturbances (20-40%), a sample of 200 subjects will allow a margin of error of 6-7%. The LBBB-TAVI Study has been in an active recruiting phase since September 2015 (21 patients already included). Local ethics committee authorisation was obtained in May 2015. We will publish findings from this study in a peer-reviewed scientific journal and present results at national and international conferences. NCT02482844; Pre-results. Published by the BMJ Publishing Group Limited. For

  9. Prognosis assessment of persistent left bundle branch block after TAVI by an electrophysiological and remote monitoring risk-adapted algorithm: rationale and design of the multicentre LBBB–TAVI Study

    Science.gov (United States)

    Massoullié, Grégoire; Bordachar, Pierre; Irles, Didier; Caussin, Christophe; Da Costa, Antoine; Defaye, Pascal; Jean, Frédéric; Mechulan, Alexis; Mondoly, Pierre; Souteyrand, Géraud; Pereira, Bruno; Ploux, Sylvain; Eschalier, Romain

    2016-01-01

    Introduction Percutaneous aortic valve replacement (transcatheter aortic valve implantation (TAVI)) notably increases the likelihood of the appearance of a complete left bundle branch block (LBBB) by direct lesion of the LBB of His. This block can lead to high-grade atrioventricular conduction disturbances responsible for a poorer prognosis. The management of this complication remains controversial. Method and analysis The screening of LBBB after TAVI persisting for more than 24 hours will be conducted by surface ECG. Stratification will be performed by post-TAVI intracardiac electrophysiological study. Patients at high risk of conduction disturbances (≥70 ms His–ventricle interval (HV) or presence of infra-Hisian block) will be implanted with a pacemaker enabling the recording of disturbance episodes. Those at lower risk (HV <70 ms) will be implanted with a loop recorder device with remote monitoring of cardiovascular implantable electronic devices (CIEDs). Clinical, ECG and implanted device follow-up will also be performed at 3, 6 and 12 months. The primary objective is to assess the efficacy and safety of a decisional algorithm based on electrophysiological study and remote monitoring of CIEDs in the prediction of high-grade conduction disturbances in patients with LBBB after TAVI. The primary end point is to compare the incidence (rate and time to onset) of high-grade conduction disturbances in patients with LBBB after TAVI between the two groups at 12 months. Given the proportion of high-grade conduction disturbances (20–40%), a sample of 200 subjects will allow a margin of error of 6–7%. The LBBB–TAVI Study has been in an active recruiting phase since September 2015 (21 patients already included). Ethics and dissemination Local ethics committee authorisation was obtained in May 2015. We will publish findings from this study in a peer-reviewed scientific journal and present results at national and international conferences. Trial

  10. Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block; Perfusao miocardica de estresse com dipiridamol por tomografia computadorizada em pacientes com bloqueio de ramo esquerdo

    Energy Technology Data Exchange (ETDEWEB)

    Cabeda, Estevan Vieira; Rochitte, Carlos Eduardo; Nomura, Cesar Higa; Parga, Jose Rodrigues; Avila, Luiz Francisco Rodrigues; Falcao, Andrea Maria Gomes; Soares Junior, Jose [Instituto do Coracao (InCor), Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil)

    2015-12-15

    Background: Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB). Objective: To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP) by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA) (stenosis ≥ 70%) as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA) and compare the results with those of single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy. Methods: Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography. Independent examiners performed per-patient and per-coronary territory assessments. All patients gave written informed consent to participate in the study that was approved by the institution's ethics committee. Results: The patients' mean age was 62 ± 10 years. The mean dose of radiation for the tomography protocol was 9.3 ± 4.6 mSv. With regard to CTP, the per-patient values for sensitivity, specificity, positive and negative predictive values, and accuracy were 86%, 81%, 80%, 87%, and 83%, respectively (p = 0.001). The per-territory values were 63%, 86%, 65%, 84%, and 79%, respectively (p < 0.001). In both analyses, the addition of CTP to CTA achieved higher diagnostic accuracy for detecting myocardial ischemia than SPECT (p < 0.001). Conclusion: The use of the stress tomography protocol is feasible and has good diagnostic accuracy for assessing myocardial ischemia in patients with LBBB. (author)

  11. Age, prognostic impact of QRS prolongation and left bundle branch block, and utilization of cardiac resynchronization therapy: findings from 14,713 patients in the Swedish Heart Failure Registry.

    Science.gov (United States)

    Lund, Lars H; Benson, Lina; Ståhlberg, Marcus; Braunschweig, Frieder; Edner, Magnus; Dahlström, Ulf; Linde, Cecilia

    2014-10-01

    Age is not a contraindication to cardiac resynchronization therapy (CRT), but the prevalence and prognostic impact of QRS prolongation with intraventricular conduction delay (IVCD) and left bundle branch block (LBBB), as well as CRT utilization, may differ with age. We tested the hypotheses that in the elderly: (i) IVCD and LBBB are more prevalent, (ii) IVCD and LBBB are more harmful, and (iii) CRT is underutilized. We studied 14 713 patients with ejection fraction ≤39% in the Swedish Heart Failure Registry and divided into age groups ≤65 years, 66-80 years and >80 years. Among 13 782 patients without CRT, IVCD was present in the three age groups in 11% vs. 15% vs. 19% and LBBB was present in 20% vs. 27% vs. 28%, respectively, (P 80 year group. For LBBB vs. narrow QRS it was 1.29 (1.07-1.56, P = 0.009), 1.17 (1.06-1.30, P = 0.002), and 1.10 (0.99-1.22, P = 0.091), respectively. The adjusted P for interaction between age and QRS morphology was 0.664. In the three age groups, CRT was present in 6% vs. 8% vs. 4% and absent but with indication in 23% vs. 32% vs. 37%, respectively (P < 0.001). Both IVCD and LBBB were more common with increasing age and were similarly strong independent predictors of mortality and in all ages. The underutilization of CRT was worse with increasing age. © 2014 The Authors. European Journal of Heart Failure © 2014 European Society of Cardiology.

  12. Physiologic Insights and Clinical Consequences of Mechanical Discoordination in Left Bundle Brranch Block

    NARCIS (Netherlands)

    Leenders, G.E.H.

    2016-01-01

    Conduction disturbances are present in a large number of heart failure patients. In particular left bundle branch block has subsequent deleterious effects on cardiac structure, function, and efficiency. Cardiac resynchronization therapy is a device based therapy that aims to improve cardiac

  13. Impact of New-Onset Left Bundle Branch Block and Periprocedural Permanent Pacemaker Implantation on Clinical Outcomes in Patients Undergoing Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Regueiro, Ander; Abdul-Jawad Altisent, Omar; Del Trigo, María; Campelo-Parada, Francisco; Puri, Rishi; Urena, Marina; Philippon, François; Rodés-Cabau, Josep

    2016-05-01

    Available data on the clinical impact of new-onset left bundle branch block (LBBB) and permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement (TAVR) remains controversial. We aimed to evaluate the impact of (1) periprocedural new-onset LBBB or PPI post-TAVR on cardiac mortality and all-cause 1-year mortality and (2) new-onset LBBB on the need for PPI at 1-year follow-up. We performed a systematic search from PubMed and EMBASE databases for studies reporting raw data on new-onset LBBB post-TAVR and the need for PPI or mortality at 1-year follow-up, or on 1-year mortality according to the need for periprocedural PPI post-TAVR. Data from 17 studies, including 4756 patients (8 studies) and 7032 patients (11 studies) for the evaluation of the impact of new-onset LBBB and periprocedural PPI post-TAVR were sourced, respectively (with 2 studies used for both outcomes). New-onset LBBB post-TAVR was associated with a higher risk of PPI (risk ratio [RR], 2.18; 95% confidence interval [CI], 1.28-3.70) and cardiac death (RR, 1.39; 95% CI, 1.04-1.86) during follow-up, as well with a tendency toward an increase in all-cause mortality (RR, 1.21; 95% CI, 0.98-1.50). Periprocedural PPI post-TAVR was not associated with any increased risk of all-cause mortality at 1 year (RR, 1.03; 95% CI, 0.9-1.18), yet a tendency toward a protective effect on cardiac death was observed (RR, 0.78; 95% CI, 0.60-1.03). New-onset LBBB post-TAVR is a marker of an increased risk of cardiac death and need for PPI at 1-year follow-up. The need for PPI early post-TAVR did not increase the risk of death. © 2016 American Heart Association, Inc.

  14. Incessant slow bundle branch reentrant ventricular tachycardia in a young patient with left ventricular noncompaction.

    Science.gov (United States)

    Barra, Sérgio; Moreno, Nuno; Providência, Rui; Gonçalves, Helena; Primo, João José

    2013-06-01

    A 15-year-old girl was admitted to the cardiology outpatient clinic due to mild palpitations and documented incessant slow ventricular tachycardia (VT) with left bundle branch block (LBBB) pattern. The baseline electrocardiogram revealed first-degree atrioventricular block and intraventricular conduction defect. Transthoracic echocardiography showed prominent trabeculae and intertrabecular recesses suggesting left ventricular noncompaction (LVNC), which was confirmed by cardiac magnetic resonance imaging. During electrophysiological study, a sustained bundle branch reentrant VT with LBBB pattern and cycle length of 480 ms, similar to the clinical tachycardia, was easily and reproducibly inducible. As there was considerable risk of need for chronic ventricular pacing following right bundle ablation, no ablation was attempted and a cardioverter-defibrillator was implanted. To the best of our knowledge, no case reports of BBR-VT as the first manifestation of LVNC have been published. Furthermore, this is an extremely rare presentation of BBR-VT, which is usually a highly malignant arrhythmia. Copyright © 2012 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  15. Multiple-Block Ahead Branch Predictors

    OpenAIRE

    Seznec, André; Jourdan, Stéphan; Sainrat, Pascal; Michaud, Pierre

    1996-01-01

    A basic rule in computer architecture is that a processor cannot execute an application faster than it fetches its instructions. To overcome the instruction fetch bottleneck shown in wide-dispatch «brainiac» processors, this paper presents a novel cost-effective mechanism called the multiple-block ahead branch predictor that predicts in an efficient way addresses of multiple basic blocks in a single cycle. Moreover and unlike the previous multiple predictor schemes, the multiple-block ahead b...

  16. Bundle-branch reentry ventricular tachycardia after transcatheter aortic valve replacement

    Directory of Open Access Journals (Sweden)

    Adriana de la Rosa Riestra

    2015-09-01

    Full Text Available An 83-year-old male suffering from severe symptomatic aortic valve stenosis received an implant of a biological aortic prosthesis through the femoral artery without complications. Seven days after dischargement he experienced a syncope. The patient was wearing an ECG holter monitor that day, which showed a wide QRS complex tachycardia of 300 beats per minute. The electrophysiological study revealed a bundle-branch reentry ventricular tachycardia as the cause of the syncope. Radio-frequency was applied on the right-bundle branch. Twelve months later, the patient has remained asymptomatic.

  17. Permanent His Bundle Pacing in Intra-Hisian Conduction Block: Mechanistic Insights.

    Science.gov (United States)

    Herweg, Bengt; Gerczuk, Paul Z; Sofi, Aamir; Vijayaraman, Pugazhendhi; Barold, S Serge

    2017-06-09

    We are reporting a patient with discrete intra-His conduction block and describe a refined technique of permanent His bundle pacing assuring reliable ventricular capture. Meticulous mapping of the site of block with lead placement distal to the site of block and non-selective His bundle pacing with local myocardial capture as an additional safety back up appears to be the technique of choice. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Functional aspects of His bundle physiology and pathophysiology: Clinical implications.

    Science.gov (United States)

    Scherlag, Benjamin J; Lazzara, Ralph

    In this review we present evidence from many experimental studies which challenge the concept of predestination of His bundle fibers. Using both intra- and extracellular His bundle pacing in the context of atrio-ventricular block and the development of bundle branch blocks these experimental studies provide the underlying mechanisms for the recent clinical findings showing the benefits of permanent His bundle pacing. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. The Bundle of His in Prosthetic Heart Valve Replacement*

    African Journals Online (AJOL)

    1973-01-27

    Jan 27, 1973 ... ventricular seplUm which transected the bundle of His. Blocks were then fashioned backwards and forwards.. to include the whole of the bundle and the AV node. as well as the bifurcation of the bundle into its left and right branches. According to Davies: in order to study the whole conduction system in an ...

  20. Effects of fuel relocation on reflood in a partially-blocked rod bundle

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byoung Jae [School of Mechanical Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134 (Korea, Republic of); Kim, Jongrok; Kim, Kihwan; Bae, Sung Won [Thermal-Hydraulic Safety Research Division, Korea Atomic Energy Research Division, 111 Daedeok-daero, Yuseong-gu, Daejeon 34057 (Korea, Republic of); Moon, Sang-Ki, E-mail: skmoon@kaeri.re.kr [Thermal-Hydraulic Safety Research Division, Korea Atomic Energy Research Division, 111 Daedeok-daero, Yuseong-gu, Daejeon 34057 (Korea, Republic of)

    2017-02-15

    Ballooning of the fuel rods has been an important issue, since it can influence the coolability of the rod bundle in a large-break loss-of-coolant accident (LBLOCA). Numerous past studies have investigated the effect of blockage geometry on the heat transfer in a partially blocked rod bundle. However, they did not consider the occurrence of fuel relocation and the corresponding effect on two-phase heat transfer. Some fragmented fuel particles located above the ballooned region may drop into the enlarged volume of the balloon. Accordingly, the fuel relocation brings in a local power increase in the ballooned region. The present study’s objective is to investigate the effect of the fuel relocation on the reflood under a LBLOCA condition. Toward this end, experiments were performed in a 5 × 5 partially-blocked rod bundle. Two power profiles were tested: one is a typical cosine shape and the other is the modified shape considering the effect of the fuel relocation. For a typical power shape, the peak temperature in the ballooned rods was lower than that in the intact rods. On the other hand, for the modified power shape, the peak temperature in the ballooned rods was higher than that in the intact rods. Numerical simulations were also performed using the MARS code. The tendencies of the peak clad temperatures were well predicted.

  1. Geometric Quality Assessment of Bundle Block Adjusted Mulit- Sensor Satellite Imageries

    Science.gov (United States)

    Ghosh, S.; Bhawani Kumar, P. S.; Radhadevi, P. V.; Srinivas, V.; Saibaba, J.; Varadan, G.

    2014-11-01

    The integration of multi-sensor earth observation data belonging to same area has become one of the most important input for resource mapping and management. Geometric error and fidelity between adjacent scenes affects large-area digital mosaic if the images/ scenes are processed independently. A block triangulation approach "Bundle Block Adjustment (BBA)" system has been developed at ADRIN for combined processing of multi-sensor, multi-resolution satellite imagery to achieve better geometric continuity. In this paper we present the evaluation results of BBA software along with performance assessment and operational use of products thus generated. The application evaluation deals with functional aspects of block-adjustment of satellite imagery consisting of data from multiple sources, i.e. AWiFs, LISS-3, LISS-4 and Cartosat-1 in various combinations as single block. It has provision for automatic generation of GCPs and tie-points using image metafile/ Rational Polynomial Coefficient's (RPC's) and ortho/ merged/ mosaicked products generation. The study is carried out with datasets covering different terrain types (ranging from high mountainous area, moderately undulating terrain, coastal plain, agriculture fields, urban area and water-body) across Indian subcontinent with varying block sizes and spatial reference systems. Geometric accuracy assessment is carried out to figure out error propagation at scene based ortho/ merged products as well as block level. The experimental results confirm that pixel tagging, geometric fidelity and feature continuity across adjacent scenes as well as for multiple sensors reduced to a great extent, due to the high redundancy. The results demonstrate that it is one of the most affective geometric corrections for generating large area digital mosaic over High mountainous terrain using high resolution good swath satellite imagery, like Cartosat-1, with minimum human intervention.

  2. Bundle Block Adjustment of Airborne Three-Line Array Imagery Based on Rotation Angles

    Directory of Open Access Journals (Sweden)

    Yongjun Zhang

    2014-05-01

    Full Text Available In the midst of the rapid developments in electronic instruments and remote sensing technologies, airborne three-line array sensors and their applications are being widely promoted and plentiful research related to data processing and high precision geo-referencing technologies is under way. The exterior orientation parameters (EOPs, which are measured by the integrated positioning and orientation system (POS of airborne three-line sensors, however, have inevitable systematic errors, so the level of precision of direct geo-referencing is not sufficiently accurate for surveying and mapping applications. Consequently, a few ground control points are necessary to refine the exterior orientation parameters, and this paper will discuss bundle block adjustment models based on the systematic error compensation and the orientation image, considering the principle of an image sensor and the characteristics of the integrated POS. Unlike the models available in the literature, which mainly use a quaternion to represent the rotation matrix of exterior orientation, three rotation angles are directly used in order to effectively model and eliminate the systematic errors of the POS observations. Very good experimental results have been achieved with several real datasets that verify the correctness and effectiveness of the proposed adjustment models.

  3. Early steps of HIV-1 fusion define the sensitivity to inhibitory peptides that block 6-helix bundle formation.

    Directory of Open Access Journals (Sweden)

    Kosuke Miyauchi

    2009-09-01

    Full Text Available The HIV envelope (Env glycoprotein mediates membrane fusion through sequential interactions with CD4 and coreceptors, followed by the refolding of the transmembrane gp41 subunit into the stable 6-helix bundle (6HB conformation. Synthetic peptides derived from the gp41 C-terminal heptad repeat domain (C-peptides potently inhibit fusion by binding to the gp41 pre-bundle intermediates and blocking their conversion into the 6HB. Our recent work revealed that HIV-1 enters cells by fusing with endosomes, but not with the plasma membrane. These studies also showed that, for the large part, gp41 pre-bundles progress toward 6HBs in endosomal compartments and are thus protected from external fusion inhibitors. Here, we examined the consequences of endocytic entry on the gp41 pre-bundle exposure and on the virus' sensitivity to C-peptides. The rates of CD4 and coreceptor binding, as well as the rate of productive receptor-mediated endocytosis, were measured by adding specific inhibitors of these steps at varied times of virus-cell incubation. Following the CD4 binding, CCR5-tropic viruses recruited a requisite number of coreceptors much faster than CXCR4-tropic viruses. The rate of subsequent uptake of ternary Env-CD4-coreceptor complexes did not correlate with the kinetics of coreceptor engagement. These measurements combined with kinetic analyses enabled the determination of the lifetime of pre-bundle intermediates on the cell surface. Overall, these lifetimes correlated with the inhibitory potency of C-peptides. On the other hand, the basal sensitivity to peptides varied considerably among diverse HIV-1 isolates and ranked similarly with their susceptibility to inactivation by soluble CD4. We conclude that both the longevity of gp41 intermediates and the extent of irreversible conformational changes in Env upon CD4 binding determine the antiviral potency of C-peptides.

  4. The electromechanical substrate for response to cardiac resynchronization therapy in patients with right bundle branch block

    DEFF Research Database (Denmark)

    Atwater, Brett D; Wagner, Galen S; Kisslo, Joseph

    2017-01-01

    BACKGROUND: Some patients with RBBB may respond to cardiac resynchronization therapy (CRT). However, little is known regarding the electromechanical substrate for CRT and whether this is the optimal pacing strategy. METHODS: This was a pilot prospective double crossover randomized controlled clin...

  5. Discordant vs. concordant left bundle branch block: A potential clinical significance.

    Science.gov (United States)

    Khalil, Jalkh; Bernard, Abi Saleh; Maurice, Khoury; Zaheer, Yousef; Marwan, Refaat; Abdallah, Rebeiz; Samir, Alam; Hadi, Skouri

    2016-01-01

    LBBB in heart failure patients has prognostic significance. Subtypes of LBBB (concordant and discordant) have not been considered when considering management. The aim of this study is to explore the clinical difference between the two subtypes. 216 patients with LBBB were included and categorized into concordant (LBBBC) and discordant (LBBBD) groups. Of the 216 patients (age 69.13±11.7; 56% male 44% female), 133 (61.5%) were LBBBD and 83 (38.5%) were LBBBC. LBBBD patients presented with lower LVEF (mean 36% vs 51%; P<0.001), wider QRS (mean 160 ms vs 151 ms; P<0.001), larger LA (mean 45 cm(2) vs 40 cm(2); P<0.001), moderate to severe mitral and tricuspid regurgitation (17% vs 3%; P<0.05, 10% vs 1%; P<0.05 respectively), CKD (41% vs 18%; P<0.001), COPD (4.6% vs 0%; P<0.01), CAD (67% vs 36%; P<0.001), and CABG (39% vs 16%; P<0.001). LBBBD is significantly associated with worse cardiac function and clinical characteristics. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Is regadenoson an appropriate stressor for MPI in patients with left bundle branch block or pacemakers?

    Science.gov (United States)

    Thomas, Gregory S; Kinser, Carissa R; Kristy, Rita; Xu, Jiaqiong; Mahmarian, John J

    2013-12-01

    Patients with LBBB or ventricular pacemaker undergoing MPI are at risk for false positive MPI results in the setting of an elevated heart rate (HR) with exercise or dobutamine stress. The areas of increased apparent ischemia are typically the LAD and septal territories. In a subanalysis of the ADVANCE MPI 1 and 2 studies, perfusion on an initial adenosine and a second MPI study with regadenoson or adenosine was compared by visual and quantitative analysis. Among 2,015 patients, 64 had LBBB and 93 had pacemakers. The hemodynamic response during the second scan was compared in those with and without LBBB and PM. Following regadenoson, peak HR in the LBBB group increased by a mean of 25.4 compared to 15.3 bpm following adenosine (P = .0083). In the pacemaker group HR was blunted, 11.8 and 8.1 following regadenoson and adenosine, respectively (P = .1262). However, the visually assessed summed difference score and the quantitatively assessed extent of ischemia for the LAD and septal territories and the entire LV did not differ between the initial adenosine and subsequent regadenoson scans. The significant increase in HR observed with regadenoson compared to adenosine did not translate into greater perfusion defects in the LAD or septal territories in patients undergoing regadenoson stress.

  7. Validation of an automatic diagnosis of strict left bundle branch block criteria using 12-lead electrocardiograms

    DEFF Research Database (Denmark)

    Xia, Xiaojuan; Ruwald, Anne-Christine; Ruwald, Martin H

    2017-01-01

    developed a series of algorithms to automatically detect and measure parameters required for strict LBBB criteria and proposed a definition of QRS notch detection. The algorithms were developed using training (n = 20) and validation (n = 592) sets consisting of signal-averaged 12-lead ECGs (1,000 Hz...... variability and 32 ECGs for interobserver variability. We assessed the performance of the automated algorithms using manually adjudicated ECGs as references. RESULTS: Overall sensitivity and specificity for detecting strict LBBB were 95% and 86%, respectively. The mean absolute deviation (MAD) of QRS duration...... the automatic method. In addition 95% and 93% agreements for notches and 90% and 88% agreements for slurs were reached for intra- and interobserver. CONCLUSION: The proposed algorithms automatically measure QRS features for the diagnosis of strict LBBB. Our study shows good performance in reference to manual...

  8. A Randomized Comparison Between Ultrasound- and Fluoroscopy-Guided Sacral Lateral Branch Blocks.

    Science.gov (United States)

    Finlayson, Roderick J; Etheridge, John-Paul B; Elgueta, Maria Francisca; Thonnagith, Atikun; De Villiers, Frederick; Nelems, Bill; Tran, De Q

    This randomized trial compared ultrasound (US)- and fluoroscopy-guided sacral lateral branch (SLB) blocks. We hypothesized that US would require a shorter performance time. Forty patients who required unilateral sacral lateral branch blocks for chronic low back pain were randomized to US or fluoroscopy guidance. Before the performance of the assigned block, an investigator who was not involved in patient care carried out baseline analgesic testing. With US, the dorsal sacroiliac ligament, the sacroiliac joint, and the interosseous ligament were probed with a 22-gauge block needle. The patient was asked to rate the level of discomfort using an 11-point numerical rating scale.After the analgesic test, attending anesthesiologists or supervised trainees carried out the SLB blocks. The local anesthetic agent (lidocaine 2%) was identical in all subjects. In the US group, local anesthetic (1.5 mL) was first injected on the lateral crest at the mid-point between S2 and S3. Subsequently, 2 more injections of 0.5 mL were carried out on the lateral crest, immediately cephalad to S2 and at the S1 level. In the fluoroscopy group, SLB blocks were performed according to a previously described 17-injection technique, which involves 9 skin entry sites and the targeting of the L5 posterior root and S1-S3 sacral lateral branches. A 0.4-mL volume of local anesthetic was deposited at each target point. The performance time, number of needle passes, and the incidence of vascular breach were recorded during the performance of the block.Twenty minutes after the end of local anesthetic injection, the same investigator who performed preblock analgesic testing carried out postblock testing in an identical manner. Compared with fluoroscopy, the US technique was associated with a shorter performance time (267.5 ± 99.3 vs 628.7 ± 120.3 seconds; P block effect (ie, the proportional decrease in numerical rating scale between preblock and postblock analgesic testing) was similar in both groups

  9. The significance of dissociation of conduction in the canine His bundle. Electrophysiological studies in vivo and in vitro.

    Science.gov (United States)

    Scherlag, B J; El-Sherif, N; Hope, R R; Lazzara, R

    1978-10-01

    Fractionated His bundle potentials were induced by ischemia or trauma in 30 anesthetized dogs, in vivo. Functional dissociation, i.e., alteration of the activation sequence of portions of these His bundle potentials was demonstrated in vivo as well as in 10 in vitro preparations of the His-Purkinje system. In vivo, plunge wire and electrode catheters were utilized to record from portions of the His bundle. During vagal-induced slowing of the heart rate, atrial pacing or His bundle pacing, His-Purkinje conduction as measured by the H-V interval was constant over a wide range of heart rates, 50-300/min. One or two hours after anterior septal artery ligation, His bundle damage manifested as split His bundle potentials (H, H'). Atrial pacing or proximal His bundle pacing induced H-H' delays with concomitant right or left bundle branch block patterns in ECG leads. However, distal His bundle pacing at comparable or even higher rates produced normal QRS complexes. In other cases, during atrial pacing or with progressive ischemia at a constant rate, H' progressively delayed during the H-V interval or even disappeared into the QRS complex with a concomitant occurrence of right or left bundle branch block. In vitro, a dissected septal preparation was studied containing the His bundle, proximal and distal right bundle and left bundle branches. Normal conduction throughout the His-Purkinje system was observed at pacing rates of 30-220/min. Punctate lesions, anatomically placed above the branching His bundle caused tachycardia-dependent, complete bundle branch blocked with concurrent temporal reversal of proximal and distal His bundle action potentials. These data suggest that ischemic or traumatic lesions in the His bundle may manifest on the electrocardiogram as bundle branch block patterns. From a clinical point of view, a critical site of lesion would markedly increase the liability for A-V blocked although the electrocardiogram alone would not indicate the actual site of

  10. Rescue vitrectomy with blocked artery massage and bloodletting for branch retinal artery occlusion

    Directory of Open Access Journals (Sweden)

    Chun-Ju Lin

    2017-01-01

    Full Text Available A 61-year-old male suffered from sudden blurred vision and superior visual field defect oculus dexter. His vision was counting fingers at 20 cm. Fundoscopy demonstrated inferior pale retina and a large embolus located at the proximal inferior retinal artery. Branch retinal artery occlusion (BRAO was diagnosed. Initial paracentesis, topical brimonidine tartrate, oral pentoxifylline, and hyperbaric oxygen therapy were performed but showed limited improvement. Hence, he received 25-gauge vitrectomy, artificial posterior vitreous detachment, blocked retinal artery massage, and bloodletting 5 days after onset. After the surgery, his vision improved to 20/25. Fundoscopy showed reperfused retina, and optical coherence tomography revealed resolved retinal edema. RAO is an ophthalmological emergency; however, no standard guideline is available. Vitrectomy with blocked retinal artery massage and bloodletting showed favorable results in this case of BRAO with a large embolus. More prospective clinical trials are needed for setting up the standard treatment.

  11. [Ultrasound-guided cutaneous intercostal branches nerves block: A good analgesic alternative for gallbladder open surgery].

    Science.gov (United States)

    Fernández Martín, M T; López Álvarez, S; Mozo Herrera, G; Platero Burgos, J J

    2015-12-01

    Laparoscopic cholecystectomy has become the standard treatment for gallbladder diseases. However, there are still some patients for whom conversion to open surgery is required. This surgery can produce significant post-operative pain. Opioids drugs have traditionally been used to treat this pain, but side effects have led to seeking alternatives (plexus, nerve or fascia blocks or wound). The cases are presented of 4 patients subjected to ultrasound-guided intercostal branches blocks in the mid-axillary line from T6 to T12 with levobupivacaine as an analgesic alternative in open surgery of gallbladder, with satisfactory results. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. Twisted vector bundles on pointed nodal curves

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    DEFINITION 2.5. Let C → S be an n-pointed nodal curve over a k-scheme S and let ξ be a principal G- bundle on Cgen. A chart (U, η, ) for ξ is called balanced, if for each ... branches is via multiplication with primitive roots of unity which are inverse to each other. ...... Condition (16) implies that A0 is a block matrix of the form.

  13. Current concepts relating coronary flow, myocardial perfusion and metabolism in left bundle branch block and cardiac resynchronisation therapy.

    Science.gov (United States)

    Claridge, Simon; Chen, Zhong; Jackson, Tom; Sammut, Eva; Sohal, Manav; Behar, Jonathan; Razavi, Reza; Niederer, Steven; Rinaldi, Christopher Aldo

    2015-02-15

    Cardiac resynchronisation therapy (CRT) improves mortality and symptoms in heart failure patients with electromechanically dyssynchronous ventricles. There is a 50% non-response rate and reproducible biomarkers to predict non-response have not been forthcoming. Therefore, there has been increasing interest in the pathophysiological effects of dyssynchrony particularly focusing on coronary flow, myocardial perfusion and metabolism. Studies suggest that dyssynchronous electrical activation effects coronary flow throughout the coronary vasculature from the epicardial arteries to the microvascular bed and that these changes can be corrected by CRT. The effect of both electrical and mechanical dyssynchrony on myocardial perfusion is unclear with some studies suggesting there is a reduction in septal perfusion whilst others propose that there is an increase in lateral perfusion. Better understanding of these effects offers the possibility for better prediction of non-response. CRT appears to improve homogeneity in myocardial perfusion where heterogeneity is described in the initial substrate. Novel approaches to the identification of non-responders via metabolic phenotyping both invasively and non-invasively have been encouraging. There remains a need for further research to clarify the interaction of coronary flow with perfusion and metabolism in patients who undergo CRT. Crown Copyright © 2014. Published by Elsevier Ireland Ltd. All rights reserved.

  14. The inhibition of prions through blocking prion conversion by permanently charged branched polyamines of low cytotoxicity.

    Science.gov (United States)

    Lim, Yong-beom; Mays, Charles E; Kim, Younghwan; Titlow, William B; Ryou, Chongsuk

    2010-03-01

    Branched polyamines are effective in inhibiting prions in a cationic surface charge density dependent manner. However, toxicity associated with branched polyamines, in general, often hampers the successful application of the compounds to treat prion diseases. Here, we report that constitutively maintained cationic properties in branched polyamines reduced the intrinsic toxicity of the compounds while retaining the anti-prion activities. In prion-infected neuroblastoma cells, quaternization of amines in polyethyleneimine (PEI) and polyamidoamine (PAMAM) dendrimers markedly increased the nontoxic concentration ranges of the compounds and still supported, albeit reduced, an appreciable level of anti-prion activity in clearing prions from the infected cells. Furthermore, quaternized PEI was able to degrade prions at acidic pH conditions and inhibit the in vitro prion propagation facilitated by conversion of the normal prion protein isoform to its misfolded counterpart, although such activities were decreased by quaternization. Quaternized PAMAM was least effective in degrading prions but efficiently inhibited prion conversion with the same efficacy as unmodified PAMAM. Our results suggest that quaternization represents an effective strategy for developing nontoxic branched polyamines with potent anti-prion activity. This study highlights the importance of polyamine structural control for developing polyamine-based anti-prion agents and understanding of an action mechanism of quaternized branched polyamines. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  15. Self calibration of the stereo vision system of the Chang'e-3 lunar rover based on the bundle block adjustment

    Science.gov (United States)

    Zhang, Shuo; Liu, Shaochuang; Ma, Youqing; Qi, Chen; Ma, Hao; Yang, Huan

    2017-06-01

    The Chang'e-3 was the first lunar soft landing probe of China. It was composed of the lander and the lunar rover. The Chang'e-3 successful landed in the northwest of the Mare Imbrium in December 14, 2013. The lunar rover completed the movement, imaging and geological survey after landing. The lunar rover equipped with a stereo vision system which was made up of the Navcam system, the mast mechanism and the inertial measurement unit (IMU). The Navcam system composed of two cameras with the fixed focal length. The mast mechanism was a robot with three revolute joints. The stereo vision system was used to determine the position of the lunar rover, generate the digital elevation models (DEM) of the surrounding region and plan the moving paths of the lunar rover. The stereo vision system must be calibrated before use. The control field could be built to calibrate the stereo vision system in the laboratory on the earth. However, the parameters of the stereo vision system would change after the launch, the orbital changes, the braking and the landing. Therefore, the stereo vision system should be self calibrated on the moon. An integrated self calibration method based on the bundle block adjustment is proposed in this paper. The bundle block adjustment uses each bundle of ray as the basic adjustment unit and the adjustment is implemented in the whole photogrammetric region. The stereo vision system can be self calibrated with the proposed method under the unknown lunar environment and all parameters can be estimated simultaneously. The experiment was conducted in the ground lunar simulation field. The proposed method was compared with other methods such as the CAHVOR method, the vanishing point method, the Denavit-Hartenberg method, the factorization method and the weighted least-squares method. The analyzed result proved that the accuracy of the proposed method was superior to those of other methods. Finally, the proposed method was practical used to self calibrate the

  16. A computer heart model incorporating anisotropic propagation. II. Simulations of conduction block.

    Science.gov (United States)

    Lorange, M; Gulrajani, R M; Nadeau, R A; Préda, I

    1993-10-01

    This study describes the simulation of the more common types of conduction blocks with a computer model of the heart incorporating anisotropic propagation. The rationale was to test the model as to its ability to simulate these blocks by physiologically justifiable adjustments of the conduction system alone. The complete blocks were generated by simply blocking conduction totally at selected sites in the proximal conduction system, and the incomplete blocks by slowing down the conduction velocity in the proximal system. Also simulated were the left fascicular blocks and the bilateral blocks. All simulated electrocardiograms, vectorcardiograms, body surface potential maps, and epicardial isochrones for these blocks were similar to clinically observed data, with the exception of the left posterior hemiblock, which was slightly atypical. This could be because such blocks are usually accompanied by other cardiac pathologies not included in our simulations. The model also supports van Dam's observation that during left bundle branch block the passage of activation from right to left occurs via slow myocardial activation with no evidence of a local delay due to a septal barrier. Finally, the model suggests that a left bundle branch block with a normal frontal plane QRS axis may simply represent a case of an incomplete left bundle block, whereas one that exhibits a left axis QRS deviation in the frontal plane represents a more severe complete left bundle branch block.

  17. Twist-off purification of hair bundles.

    Science.gov (United States)

    Shin, Jung-Bum; Pagana, James; Gillespie, Peter G

    2009-01-01

    Purification of hair bundles from inner-ear organs allows biochemical analysis of bundle constituents, including proteins and lipids. We describe here the "twist-off" method of bundle isolation, where dissected inner-ear organs are embedded in agarose, then subjected to a mechanical disruption that shears off bundles and leaves them in agarose blocks. With care in the dissection and in clean-up of the isolated bundles, contamination from cell bodies can be kept to a minimum. Isolated bundles can be analyzed by a variety of techniques, including immunocytochemistry, SDS-PAGE, immunoblotting, and mass spectrometry.

  18. Automatic Tie-point Extraction Based on Multiple-image Matching and Bundle Adjustment of Large Block of Oblique Aerial Images

    Directory of Open Access Journals (Sweden)

    ZHANG Li

    2017-05-01

    Full Text Available Due to advantages such as ease of interpretation, completeness through mitigation of occluding areas, as well as system accessibility, the aerial oblique images have found their place in numerous civil applications. However, for these applications high quality orientation data are essential. A fully automatic tie-point extraction procedure is developed to precisely orient the large block of oblique aerial images, in which a refined ASIFT algorithm and a window-based multiple-viewing image matching (WMVM method are combined. In this approach, the WMVM method is based on the concept of multi-image matching guided from object space and allows reconstruction of 3D objects by matching all available images simultaneously, and a square correlation window in the reference image can be correlated with windows of different size, shape and orientation in the search images.Then another key algorithms, i.e. the combined bundle adjustment method with gross-error detection & removal algorithm, which can be used for simultaneously orient the oblique and nearly-vertical images will be presented. Finally, through the experiments by using real oblique images over several test areas, the performance and accuracy of the proposed method is studied and presented.

  19. Bundling harvester; Nippukorjausharvesteri

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, K. [Eko-Log Oy, Kuopio (Finland)

    1996-12-31

    The staring point of the project was to design and construct, by taking the silvicultural point of view into account, a harvesting and processing system especially for energy-wood, containing manually driven bundling harvester, automatizing of the harvester, and automatized loading. The equipment forms an ideal method for entrepreneur`s-line harvesting. The target is to apply the system also for owner`s-line harvesting. The profitability of the system promotes the utilization of the system in both cases. The objectives of the project were: to construct a test equipment and prototypes for all the project stages, to carry out terrain and strain tests in order to examine the usability and durability, as well as the capacity of the machine, to test the applicability of the Eko-Log system in simultaneous harvesting of energy and pulp woods, and to start the marketing and manufacturing of the products. The basic problems of the construction of the bundling harvester have been solved using terrain-tests. The prototype machine has been shown to be operable. Loading of the bundles to form sufficiently economically transportable loads has been studied, and simultaneously, the branch-biomass has been tried to be utilized without loosing the profitability of transportation. The results have been promising, and will promote the profitable utilization of wood-energy

  20. Relation of QRS Duration to Clinical Benefit of Cardiac Resynchronization Therapy in Mild Heart Failure Patients Without Left Bundle Branch Block

    DEFF Research Database (Denmark)

    Biton, Yitschak; Kutyifa, Valentina; Cygankiewicz, Iwona

    2016-01-01

    HF enrolled in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) study by QRS duration or morphology further stratified by PR interval. At 7 years of follow-up, the cumulative probability of HF hospitalization or death was 45% versus 56......% among patients randomized to implantable cardioverter-defibrillator and CRT with defibrillator (CRT-D), respectively (P=0.209). Multivariable-adjusted subgroup analysis by QRS duration showed that patients from the lower quartile QRS duration group (≤ 134 ms) experienced 2.4-fold (P=0.015) increased...... risk for HF hospitalization or death with CRT-D versus implantable cardioverter-defibrillator only therapy, whereas the effect of CRT-D in patients from the upper quartiles group (QRS>134 ms) was neutral (hazard ratio [HR] =0.97, P=0.86; P value for interaction =0.024). In a second analysis...

  1. Exercise-induced left septal fascicular block: an expression of severe myocardial ischemia

    Directory of Open Access Journals (Sweden)

    Augusto Hiroshi Uchida

    2006-04-01

    Full Text Available The electrocardiogram (ECG criteria for the left septal fascicular block (LSFB are not universally accepted and many other denominations can be seen in literature: focal septal block, septal focal block, left septal fascicular block, left anterior septal block, septal fascicular conduction disorder of the left branch, left septal Purkinje network block, left septal subdivision block of the left bundle branch, anterior conduction delay, left median hemiblock, left medial subdivision block of the left bundle branch, middle fascicle block, block of the anteromedial division of the left bundle branch of His, and anteromedial divisional block. During exercise stress test, fascicular blocks (left anterior and posterior seem to indicate severe coronary artery narrowing of left main coronary or proximal left anterior descending artery disease1 and transient exercise-induced left septal fascicular block has been reported a few times2,3. 54-year-old male, with a history of essential arterial systemic hypertension, primary hyperlipidemia and six-month typical chest pain during exercise (Class II – Canadian Cardiovascular Society underwent an exercise stress test. During the exercise stress test, ECG demonstrated abrupt prominent anterior forces, an increase in R wave amplitude from V1 to V4, extreme left axis deviation and minor ST segment depression in DII, DIII and aVF (Figure 1. The post-exercise period showed progressive return of the QRS axis in both frontal and horizontal planes and the ST depression worsened by 1 mm. Coronary angiogram (Figure 2A showed a critical proximal left anterior descending artery lesion. An exercise stress test done three months after coronary artery bypass surgery grafting was normal (Figure 2B.

  2. Selective versus non-selective his bundle pacing for cardiac resynchronization therapy.

    Science.gov (United States)

    Upadhyay, Gaurav A; Tung, Roderick

    Cardiac resynchronization therapy (CRT) has an established role in the device-based therapy for patients with systolic dysfunction and intraventricular conduction delay, particularly left bundle branch block (LBBB). Recently, His bundle pacing (HBP) has emerged as a viable alternative for resynchronization which can successfully narrow surface QRS and improve mechanical dyssynchrony. The role of selective (i.e., an isoelectric His-paced to QRS interval similar to native HV interval) versus non-selective capture (i.e., engagement of His along with adjacent local myocardial tissue and pseudo-delta wave) and outcome after HBP for resynchronization is not clear. In this article, we review the current literature (case reports and case series) reporting on HBP for resynchronization and comment on favorable predictors of response. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Complete heart block and asystole following blunt cardiac trauma

    Directory of Open Access Journals (Sweden)

    Mohamed Morsy

    2015-10-01

    Full Text Available Cardiac contusion is a well-recognized complication of blunt chest trauma. Various conduction system disorders have been reported in association with this condition, the most common being right bundle branch block. Complete heart block (CHB is seen rarely. Most cases of CHB are transient. We present the case of an 80-year-old woman who developed CHB and asystole following blunt cardiac trauma. Malignant cardiac arrhythmias such as CHB can be associated with blunt cardiac trauma. In most cases, CHB is transient resolving in days to weeks. In rare cases, however, CHB leads to asystole. Close monitoring and prompt intervention is thus required.

  4. Single Actin Bundle Rheology.

    Science.gov (United States)

    Strehle, Dan; Mollenkopf, Paul; Glaser, Martin; Golde, Tom; Schuldt, Carsten; Käs, Josef A; Schnauß, Jörg

    2017-10-24

    Bundled actin structures play an essential role in the mechanical response of the actin cytoskeleton in eukaryotic cells. Although responsible for crucial cellular processes, they are rarely investigated in comparison to single filaments and isotropic networks. Presenting a highly anisotropic structure, the determination of the mechanical properties of individual bundles was previously achieved through passive approaches observing bending deformations induced by thermal fluctuations. We present a new method to determine the bending stiffness of individual bundles, by measuring the decay of an actively induced oscillation. This approach allows us to systematically test anisotropic, bundled structures. Our experiments revealed that thin, depletion force-induced bundles behave as semiflexible polymers and obey the theoretical predictions determined by the wormlike chain model. Thickening an individual bundle by merging it with other bundles enabled us to study effects that are solely based on the number of involved filaments. These thicker bundles showed a frequency-dependent bending stiffness, a behavior that is inconsistent with the predictions of the wormlike chain model. We attribute this effect to internal processes and give a possible explanation with regard to the wormlike bundle theory.

  5. Single Actin Bundle Rheology

    Directory of Open Access Journals (Sweden)

    Dan Strehle

    2017-10-01

    Full Text Available Bundled actin structures play an essential role in the mechanical response of the actin cytoskeleton in eukaryotic cells. Although responsible for crucial cellular processes, they are rarely investigated in comparison to single filaments and isotropic networks. Presenting a highly anisotropic structure, the determination of the mechanical properties of individual bundles was previously achieved through passive approaches observing bending deformations induced by thermal fluctuations. We present a new method to determine the bending stiffness of individual bundles, by measuring the decay of an actively induced oscillation. This approach allows us to systematically test anisotropic, bundled structures. Our experiments revealed that thin, depletion force-induced bundles behave as semiflexible polymers and obey the theoretical predictions determined by the wormlike chain model. Thickening an individual bundle by merging it with other bundles enabled us to study effects that are solely based on the number of involved filaments. These thicker bundles showed a frequency-dependent bending stiffness, a behavior that is inconsistent with the predictions of the wormlike chain model. We attribute this effect to internal processes and give a possible explanation with regard to the wormlike bundle theory.

  6. Permanent His-Bundle Pacing: Case Studies.

    Science.gov (United States)

    Vijayaraman, Pugazhendhi; Dandamudi, Gopi

    2016-12-01

    His bundle pacing (HBP) is a physiological alternative to right ventricular pacing. In addition to patients with normal His-Purkinje conduction, HBP can be valuable in patients with infranodal atrioventricular (AV) block and patients undergoing AV node ablation. The following case studies illustrate the challenges associated with HBP. © 2016 Wiley Periodicals, Inc.

  7. The Role of Thoracic Medial Branch Blocks in Managing Chronic Mid and Upper Back Pain: A Randomized, Double-Blind, Active-Control Trial with a 2-Year Followup

    Directory of Open Access Journals (Sweden)

    Laxmaiah Manchikanti

    2012-01-01

    Full Text Available Study Design. A randomized, double-blind, active-control trial. Objective. To determine the clinical effectiveness of therapeutic thoracic facet joint nerve blocks with or without steroids in managing chronic mid back and upper back pain. Summary of Background Data. The prevalence of thoracic facet joint pain has been established as 34% to 42%. Multiple therapeutic techniques utilized in managing chronic thoracic pain of facet joint origin include medial branch blocks, radiofrequency neurotomy, and intraarticular injections. Methods. This randomized double-blind active controlled trial was performed in 100 patients with 50 patients in each group who received medial branch blocks with local anesthetic alone or local anesthetic and steroids. Outcome measures included the numeric rating scale (NRS, Oswestry Disability Index (ODI, opioid intake, and work status, at baseline, 3, 6, 12, 18, and 24 months. Results. Significant improvement with significant pain relief and functional status improvement of 50% or more were observed in 80% of the patients in Group I and 84% of the patients in Group II at 2-year followup. Conclusions. Therapeutic medial branch blocks of thoracic facets with or without steroids may provide a management option for chronic function-limiting thoracic pain of facet joint origin.

  8. Cytoskeletal bundle mechanics

    NARCIS (Netherlands)

    Bathe, Mark; Heussinger, Claus; Claessens, Mireille Maria Anna Elisabeth; Bausch, Andreas R.; Frey, Erwin

    2008-01-01

    The mechanical properties of cytoskeletal actin bundles play an essential role in numerous physiological processes, including hearing, fertilization, cell migration, and growth. Cells employ a multitude of actin-binding proteins to actively regulate bundle dimensions and cross-linking properties to

  9. Non-selective His bundle pacing with a biphasic waveform: enhancing septal resynchronization.

    Science.gov (United States)

    Ortega, Daniel F; Barja, Luis D; Logarzo, Emilio; Mangani, Nicolas; Paolucci, Analia; Bonomini, Maria P

    2017-05-17

    His bundle pacing has shown to prevent detrimental effects from right ventricular apical pacing (RVA) and proved to resynchronize many conduction disturbances cases. However, the extent of His bundle pacing resynchronization is limited. An optimized stimulation waveform could expand this limit when implemented in His bundle pacing sets. In this work, we temporarily implemented RVA and Non-selective His bundle pacing with a biphasic anodal-first waveform (AF-nHB) and compared their effects against sinus rhythm (SR). Fifteen patients referred for electrophysiologic study with conduction disturbances, cardiomyopathy and ejection fraction below 35% were enrolled for the study. The following acute parameters were measured: QRS duration, left ventricular activation (RLVT), time of isovolumic contraction (IVCT), ejection fraction (EF), and dP/dtmax. QRS duration and RLVT decreased markedly under AF-nHB (SR: 169 ± 34 ms vs. nHB: 116 ± 31 ms, P < 0.0005) while RVA significantly increased QRS duration (SR: 169 ms vs. RVA: 198 ms, P < 0.05) and did not change RLVT (P = NS). Consistently, IVCT moderately decreased under AF-nHB (SR: 238 ms vs. RVA: 184 ms, P < 0.05 vs. SR) and dP/dtmax showed a 93.35 [mmHg] average increase under AF-nHB against SR. Also, T-wave inversions were observed during AF-nHB immediately after SR and RVA pacing suggesting the occurrence of cardiac memory. AF-nHB corrected bundle branch blocks in patients with severe conduction disturbances, even in those with dilated cardiomiopathy, outstanding from RVA. Also, the occurrence of cardiac memory during AF-nHB turned up as an observational finding of this study.

  10. The ABCDEF Implementation Bundle

    Directory of Open Access Journals (Sweden)

    Annachiara Marra

    2016-08-01

    Full Text Available Long-term morbidity, long-term cognitive impairment and hospitalization-associated disability are common occurrence in the survivors of critical illness, with significant consequences for patients and for the caregivers. The ABCDEF bundle represents an evidence-based guide for clinicians to approach the organizational changes needed for optimizing ICU patient recovery and outcomes. The ABCDEF bundle includes: Assess, Prevent, and Manage Pain, Both Spontaneous Awakening Trials (SAT and Spontaneous Breathing Trials (SBT, Choice of analgesia and sedation, Delirium: Assess, Prevent, and Manage, Early mobility and Exercise, and Family engagement. The purpose of this review is to describe the core features of the ABCDEF bundle.

  11. Thermodynamics of fiber bundles

    OpenAIRE

    Pride, Steven R.; Toussaint, Renaud

    2002-01-01

    A recent theory that determines the properties of disordered solids as the solid accumulates damage is applied to the special case of fiber bundles with global load sharing and is shown to be exact in this case. The theory postulates that the probability of observing a given emergent damage state is obtained by maximizing the emergent entropy as defined by Shannon subject to energetic constraints. This theory yields the known exact results for the fiber-bundle model with global load sharing a...

  12. Bundles of Banach algebras

    Directory of Open Access Journals (Sweden)

    J. W. Kitchen

    1994-01-01

    Full Text Available We study bundles of Banach algebras π:A→X, where each fiber Ax=π−1({x} is a Banach algebra and X is a compact Hausdorff space. In the case where all fibers are commutative, we investigate how the Gelfand representation of the section space algebra Γ(π relates to the Gelfand representation of the fibers. In the general case, we investigate how adjoining an identity to the bundle π:A→X relates to the standard adjunction of identities to the fibers.

  13. Buying bundles: the effects of bundle attributes on the value of bundling

    OpenAIRE

    Linthorst, M.M.; Telgen, Jan; Schotanus, Fredo

    2008-01-01

    We consider the situation in which a buyer has to find the optimal degree of bundling for buying goods and services. From a review of the literature we develop attributes associated with bundling. Each of these attributes has an effect on the value of a bundle. Combined, the attributes determine the value of a bundle. We describe how the various attributes of a bundle contribute to the value of a bundle given the context of the buying situation. Based on interviews, a further analysis of bund...

  14. Buying bundles: the effects of bundling attributes on the value of bundling

    OpenAIRE

    Linthorst, M.M.; Telgen, Jan; Schotanus, Fredo

    2008-01-01

    We consider the situation in which a buyer has to find the optimal degree of bundling for buying goods and services. From a review of the literature we develop attributes associated with bundling. Each of these attributes has an effect on the value of a bundle. Combined, the attributes determine the value of a bundle. We describe how the various attributes of a bundle contribute to the value of a bundle given the context of the buying situation. Based on interviews, a further analysis of bund...

  15. ALUMINUM BOX BUNDLING PRESS

    Directory of Open Access Journals (Sweden)

    Iosif DUMITRESCU

    2015-05-01

    Full Text Available In municipal solid waste, aluminum is the main nonferrous metal, approximately 80- 85% of the total nonferrous metals. The income per ton gained from aluminum recuperation is 20 times higher than from glass, steel boxes or paper recuperation. The object of this paper is the design of a 300 kN press for aluminum box bundling.

  16. Dynamics of flagellar bundling

    Science.gov (United States)

    Janssen, Pieter; Graham, Michael

    2010-11-01

    Flagella are long thin appendages of microscopic organisms used for propulsion in low-Reynolds environments. For E. coli the flagella are driven by a molecular motor, which rotates the flagella in a counter-clockwise motion (CCM). When in a forward swimming motion, all flagella bundle up. If a motor reverses rotation direction, the flagella unbundle and the cell makes a tumbling motion. When all motors turn in the same CC direction again, the flagella bundle up, and forward swimming continues. To investigate the bundling, we consider two flexible helices next to each other, as well as several flagella attached to a spherical body. Each helix is modeled as several prolate spheroids connected at the tips by springs. For hydrodynamic interactions, we consider the flagella to made up of point forces, while the finite size of the body is incorporated via Fax'en's laws. We show that synchronization occurs quickly relative to the bundling process. For flagella next to each other, the initial deflection is generated by rotlet interactions generated by the rotating helices. At longer times, simulations show the flagella only wrap once around each other, but only for flagella that are closer than about 4 helix radii. Finally, we show a run-and-tumble motion of the body with attached flagella.

  17. Bundle pricing with comparable items

    NARCIS (Netherlands)

    Grigoriev, Alexander; van Loon, Joyce; Sviridenko, Maxim; Uetz, Marc Jochen; Vredeveld, Tjark; Arge, L.; Hoffmann, M.; Welzl, E.

    2007-01-01

    We consider a revenue maximization problem where we are selling a set of items, each available in a certain quantity, to a set of bidders. Each bidder is interested in one or several bundles of items. We assume the bidders’ valuations for each of these bundles to be known. Whenever bundle prices are

  18. Bundling ecosystem services in Denmark

    DEFF Research Database (Denmark)

    Turner, Katrine Grace; Odgaard, Mette Vestergaard; Bøcher, Peder Klith

    2014-01-01

    to form synergies. We identified six distinct ecosystem service bundle types, indicating multiple interactions at a landscape level. The bundle types showed specialized areas of agricultural production, high provision of cultural services at the coasts, multifunctional mixed-use bundle types around urban...

  19. Buying bundles: the effects of bundling attributes on the value of bundling

    NARCIS (Netherlands)

    Linthorst, M.M.; Telgen, Jan; Schotanus, Fredo

    2008-01-01

    We consider the situation in which a buyer has to find the optimal degree of bundling for buying goods and services. From a review of the literature we develop attributes associated with bundling. Each of these attributes has an effect on the value of a bundle. Combined, the attributes determine the

  20. Buying bundles: the effects of bundle attributes on the value of bundling

    NARCIS (Netherlands)

    Linthorst, M.M.; Telgen, Jan; Schotanus, Fredo

    2008-01-01

    We consider the situation in which a buyer has to find the optimal degree of bundling for buying goods and services. From a review of the literature we develop attributes associated with bundling. Each of these attributes has an effect on the value of a bundle. Combined, the attributes determine the

  1. Helices and vector bundles

    CERN Document Server

    Rudakov, A N

    1990-01-01

    This volume is devoted to the use of helices as a method for studying exceptional vector bundles, an important and natural concept in algebraic geometry. The work arises out of a series of seminars organised in Moscow by A. N. Rudakov. The first article sets up the general machinery, and later ones explore its use in various contexts. As to be expected, the approach is concrete; the theory is considered for quadrics, ruled surfaces, K3 surfaces and P3(C).

  2. Bundling harvester; Harvennuspuun automaattisen nippukorjausharvesterin kehittaeminen

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, K. [Eko-Log Oy, Kuopio (Finland)

    1997-12-01

    The starting point of the project was to design and construct, by taking the silvicultural point of view into account, a harvesting and processing system especially for energy-wood, containing manually driven bundling harvester, automating of the harvester, and automated loading. The equipment forms an ideal method for entrepreneur`s-line harvesting. The target is to apply the system also for owner`s-line harvesting. The profitability of the system promotes the utilisation of the system in both cases. The objectives of the project were: to construct a test equipment and prototypes for all the project stages, to carry out terrain and strain tests in order to examine the usability and durability, as well as the capacity of the machine, to test the applicability of the Eko-Log system in simultaneous harvesting of energy and pulp woods, and to start the marketing and manufacturing of the products. The basic problems of the construction of the bundling harvester have been solved using terrain-tests. The prototype machine has been shown to be operable. Loading of the bundles to form sufficiently economically transportable loads has been studied, and simultaneously, the branch-biomass has been tried to be utilised without loosing the profitability of transportation. The results have been promising, and will promote the profitable utilisation of wood-energy. (orig.)

  3. Bundled payments in orthopedic surgery.

    Science.gov (United States)

    Bushnell, Brandon D

    2015-02-01

    As a result of reading this article, physicians should be able to: 1. Describe the concept of bundled payments and the potential applications of bundled payments in orthopedic surgery. 2. For specific situations, outline a clinical episode of care, determine the participants in a bundling situation, and define care protocols and pathways. 3. Recognize the importance of resource utilization management, quality outcome measurement, and combined economic-clinical value in determining the value of bundled payment arrangements. 4. Identify the implications of bundled payments for practicing orthopedists, as well as the legal issues and potential future directions of this increasingly popular alternative payment method. Bundled payments, the idea of paying a single price for a bundle of goods and services, is a financial concept familiar to most American consumers because examples appear in many industries. The idea of bundled payments has recently gained significant momentum as a financial model with the potential to decrease the significant current costs of health care. Orthopedic surgery as a field of medicine is uniquely positioned for success in an environment of bundled payments. This article reviews the history, logistics, and implications of the bundled payment model relative to orthopedic surgery. Copyright 2015, SLACK Incorporated.

  4. Muon bundles from the Universe

    Directory of Open Access Journals (Sweden)

    Kankiewicz P.

    2018-01-01

    Full Text Available Recently the CERN ALICE experiment, in its dedicated cosmic ray run, observed muon bundles of very high multiplicities, thereby confirming similar findings from the LEP era at CERN (in the CosmoLEP project. Significant evidence for anisotropy of arrival directions of the observed high multiplicity muonic bundles is found. Estimated directionality suggests their possible extragalactic provenance. We argue that muonic bundles of highest multiplicity are produced by strangelets, hypothetical stable lumps of strange quark matter infiltrating our Universe.

  5. Electrostatically anchored branched brush layers.

    Science.gov (United States)

    Liu, Xiaoyan; Dedinaite, Andra; Rutland, Mark; Thormann, Esben; Visnevskij, Ceslav; Makuska, Ricardas; Claesson, Per M

    2012-11-06

    A novel type of block copolymer has been synthesized. It consists of a linear cationic block and an uncharged bottle-brush block. The nonionic bottle-brush block contains 45 units long poly(ethylene oxide) side chains. This polymer was synthesized with the intention of creating branched brush layers firmly physisorbed to negatively charged surfaces via the cationic block, mimicking the architecture (but not the chemistry) of bottle-brush molecules suggested to be present on the cartilage surface, and contributing to the efficient lubrication of synovial joints. The adsorption properties of the diblock copolymer as well as of the two blocks separately were studied on silica surfaces using quartz crystal microbalance with dissipation monitoring (QCM-D) and optical reflectometry. The adsorption kinetics data highlight that the diblock copolymers initially adsorb preferentially parallel to the surface with both the cationic block and the uncharged bottle-brush block in contact with the surface. However, as the adsorption proceeds, a structural change occurs within the layer, and the PEO bottle-brush block extends toward solution, forming a surface-anchored branched brush layer. As the adsorption plateau is reached, the diblock copolymer layer is 46-48 nm thick, and the water content in the layer is above 90 wt %. The combination of strong electrostatic anchoring and highly hydrated branched brush structures provide strong steric repulsion, low friction forces, and high load bearing capacity. The strong electrostatic anchoring also provides high stability of preadsorbed layers under different ionic strength conditions.

  6. Bundle Formation in Biomimetic Hydrogels

    NARCIS (Netherlands)

    Jaspers, Maarten; Pape, A C H; Voets, Ilja K; Rowan, Alan E; Portale, Giuseppe; Kouwer, Paul H J

    2016-01-01

    Bundling of single polymer chains is a crucial process in the formation of biopolymer network gels that make up the extracellular matrix and the cytoskeleton. This bundled architecture leads to gels with distinctive properties, including a large-pore-size gel formation at very low concentrations and

  7. Bundle Security Protocol for ION

    Science.gov (United States)

    Burleigh, Scott C.; Birrane, Edward J.; Krupiarz, Christopher

    2011-01-01

    This software implements bundle authentication, conforming to the Delay-Tolerant Networking (DTN) Internet Draft on Bundle Security Protocol (BSP), for the Interplanetary Overlay Network (ION) implementation of DTN. This is the only implementation of BSP that is integrated with ION.

  8. Fiber bundle phase conjugate mirror

    Science.gov (United States)

    Ward, Benjamin G.

    2012-05-01

    An improved method and apparatus for passively conjugating the phases of a distorted wavefronts resulting from optical phase mismatch between elements of a fiber laser array are disclosed. A method for passively conjugating a distorted wavefront comprises the steps of: multiplexing a plurality of probe fibers and a bundle pump fiber in a fiber bundle array; passing the multiplexed output from the fiber bundle array through a collimating lens and into one portion of a non-linear medium; passing the output from a pump collection fiber through a focusing lens and into another portion of the non-linear medium so that the output from the pump collection fiber mixes with the multiplexed output from the fiber bundle; adjusting one or more degrees of freedom of one or more of the fiber bundle array, the collimating lens, the focusing lens, the non-linear medium, or the pump collection fiber to produce a standing wave in the non-linear medium.

  9. The concept of double bundle ACL simulation with a single bundle patellar tendon graft. A cadaveric feasibility study.

    Science.gov (United States)

    Jacobi, Matthias; Magnussen, Robert A; Villa, Vincent; Demey, Guillaume; Neyret, Philippe

    2012-06-07

    There is significant interest in the restoration of the double-bundle anatomy of the native ACL when performing ACL reconstruction. Possible techniques include those utilizing two separate grafts with independent tunnels and those that attempt to mimic this anatomy with a single graft and fewer tunnels. Many of the latter techniques require specific instrumentation and are technically challenging. We demonstrate that the double-bundle anatomy of the native ACL can theoretically be mimicked by a single-bundle reconstruction. We performed single bundle ACL reconstruction with a bone-patellar tendon-bone (BTB) graft in two cadaveric knees. Both grafts were placed to mimic the native ACL footprints - one reconstruction was performed with rectangular bone blocks and oval tunnels and one was performed utilizing a standard BTB graft and round tunnels. Qualitative assessment of graft behavior was made as the knees were taken through a range of motion. The ACL graft was able to qualitatively mimic the behavior of the native ACL in both knees provided the bone blocks were correctly orientated. ACL reconstruction with a single BTB graft can qualitatively mimic the behavior of the two bundles of the native ACL. The key to ensuring this behavior was noted to be appropriate orientation of the graft in the tunnels. Quantitative biomechanical investigations are necessary to evaluate the impact of graft orientation on function.

  10. The concept of double bundle ACL simulation with a single bundle patellar tendon graft. A cadaveric feasibility study

    Directory of Open Access Journals (Sweden)

    Jacobi Matthias

    2012-06-01

    Full Text Available Abstract Background There is significant interest in the restoration of the double-bundle anatomy of the native ACL when performing ACL reconstruction. Possible techniques include those utilizing two separate grafts with independent tunnels and those that attempt to mimic this anatomy with a single graft and fewer tunnels. Many of the latter techniques require specific instrumentation and are technically challenging. We demonstrate that the double-bundle anatomy of the native ACL can theoretically be mimicked by a single-bundle reconstruction. Methods We performed single bundle ACL reconstruction with a bone-patellar tendon-bone (BTB graft in two cadaveric knees. Both grafts were placed to mimic the native ACL footprints – one reconstruction was performed with rectangular bone blocks and oval tunnels and one was performed utilizing a standard BTB graft and round tunnels. Qualitative assessment of graft behavior was made as the knees were taken through a range of motion. Results The ACL graft was able to qualitatively mimic the behavior of the native ACL in both knees provided the bone blocks were correctly orientated. Conclusions ACL reconstruction with a single BTB graft can qualitatively mimic the behavior of the two bundles of the native ACL. The key to ensuring this behavior was noted to be appropriate orientation of the graft in the tunnels. Quantitative biomechanical investigations are necessary to evaluate the impact of graft orientation on function.

  11. Restitution characteristics of His bundle and working myocardium in isolated rabbit hearts.

    Science.gov (United States)

    Huang, Shangwei; Wu, Liqun; Huang, Jian; Panitchob, Nuttanont; Hu, Nan; Ranjan, Ravi; Dosdall, Derek J

    2017-01-01

    The Purkinje system (PS) and the His bundle have been recently implicated as an important driver of the rapid activation rate after 1-2 minutes of ventricular fibrillation (VF). It is unknown whether activations during VF propagate through the His-Purkinje system to other portions of the the working myocardium (WM). Little is known about restitution characteristic differences between the His bundle and working myocardium at short cycle lengths. In this study, rabbit hearts (n = 9) were isolated, Langendorff-perfused, and electromechanically uncoupled with blebbistatin (10 μM). Pacing pulses were delivered directly to the His bundle. By using standard glass microelectrodes, action potentials duration (APD) from the His bundle and WM were obtained simultaneously over a wide range of stimulation cycle lengths (CL). The global F-test indicated that the two restitution curves of the His bundle and the WM are statistically significantly different (PHis bundle was significantly shorter than that of WM throughout the whole pacing course (PHis bundle vs. the WM were shorter for the His bundle (134.2±13.1ms vs. 148.3±13.3ms, PHis bundle than in WM (130.0±10.0 vs. 145.6±14.2ms, PHis bundle APD was significantly shorter than that of WM under both slow and rapid pacing rates, which suggest that there may be an excitable gap during VF and that the His bundle may conduct wavefronts from one bundle branch to the other at short cycle lengths and during VF.

  12. Semiflexible Biopolymers in Bundled Arrangements

    Directory of Open Access Journals (Sweden)

    Jörg Schnauß

    2016-07-01

    Full Text Available Bundles and networks of semiflexible biopolymers are key elements in cells, lending them mechanical integrity while also enabling dynamic functions. Networks have been the subject of many studies, revealing a variety of fundamental characteristics often determined via bulk measurements. Although bundles are equally important in biological systems, they have garnered much less scientific attention since they have to be probed on the mesoscopic scale. Here, we review theoretical as well as experimental approaches, which mainly employ the naturally occurring biopolymer actin, to highlight the principles behind these structures on the single bundle level.

  13. Branched polymers on branched polymers

    OpenAIRE

    Durhuus, Bergfinnur; Jonsson, Thordur

    1996-01-01

    We study an ensemble of branched polymers which are embedded on other branched polymers. This is a toy model which allows us to study explicitly the reaction of a statistical system on an underlying geometrical structure, a problem of interest in the study of the interaction of matter and quantized gravity. We find a phase transition at which the embedded polymers begin to cover the basis polymers. At the phase transition point the susceptibility exponent $\\gamma$ takes the value 3/4 and the ...

  14. MAVEN EUV Modelled Data Bundle

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains solar irradiance spectra in 1-nm bins from 0-190 nm. The spectra are generated based upon the Flare Irradiance Spectra Model - Mars (FISM-M)...

  15. MAVEN SWEA Calibrated Data Bundle

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains fully calibrated electron energy/angle (3D) distributions, pitch angle distributions, and omni-directional energy spectra. Tables of sensitivity...

  16. MAVEN LPW Derived Data Bundle

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains data which have been derived from other data products or determined by fits to other data. These are science quality data produced by the LPW...

  17. MAVEN LPW Calibrated Data Bundle

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains fully calibrated, science quality data produced by the LPW instrument. The data include spacecraft potential, electric field waveforms and wave...

  18. Hexagonally Ordered Arrays of α-Helical Bundles Formed from Peptide-Dendron Hybrids

    Energy Technology Data Exchange (ETDEWEB)

    Barkley, Deborah A. [Department; Rokhlenko, Yekaterina [Department; Marine, Jeannette E. [Department; David, Rachelle [Department; Sahoo, Dipankar [Department; Watson, Matthew D. [Department; Koga, Tadanori [Department; Department; Osuji, Chinedum O. [Department; Rudick, Jonathan G. [Department

    2017-10-24

    Combining monodisperse building blocks that have distinct folding properties serves as a modular strategy for controlling structural complexity in hierarchically organized materials. We combine an α-helical bundle-forming peptide with self-assembling dendrons to better control the arrangement of functional groups within cylindrical nanostructures. Site-specific grafting of dendrons to amino acid residues on the exterior of the α-helical bundle yields monodisperse macromolecules with programmable folding and self-assembly properties. The resulting hybrid biomaterials form thermotropic columnar hexagonal mesophases in which the peptides adopt an α-helical conformation. Bundling of the α-helical peptides accompanies self-assembly of the peptide-dendron hybrids into cylindrical nanostructures. The bundle stoichiometry in the mesophase agrees well with the size found in solution for α-helical bundles of peptides with a similar amino acid sequence.

  19. Principal bundles the classical case

    CERN Document Server

    Sontz, Stephen Bruce

    2015-01-01

    This introductory graduate level text provides a relatively quick path to a special topic in classical differential geometry: principal bundles.  While the topic of principal bundles in differential geometry has become classic, even standard, material in the modern graduate mathematics curriculum, the unique approach taken in this text presents the material in a way that is intuitive for both students of mathematics and of physics. The goal of this book is to present important, modern geometric ideas in a form readily accessible to students and researchers in both the physics and mathematics communities, providing each with an understanding and appreciation of the language and ideas of the other.

  20. ADE bundles over surfaces with ADE singularities

    OpenAIRE

    Chen, Yunxia; Leung, Naichung Conan

    2012-01-01

    Given a complex projective surface with an ADE singularity and p_{g}=0, we construct ADE bundles over it and its minimal resolution. Furthermore, we descibe their minuscule representation bundles in terms of configurations of (reducible) (-1)-curves.

  1. PDS4 Bundle Creation Governance Using BPMN

    Science.gov (United States)

    Radulescu, C.; Levoe, S. R.; Algermissen, S. S.; Rye, E. D.; Hardman, S. H.

    2015-06-01

    The AMMOS-PDS Pipeline Service (APPS) provides a Bundle Builder tool, which governs the process of creating, and ultimately generates, PDS4 bundles incrementally, as science products are being generated.

  2. Developing the bundled glass column

    NARCIS (Netherlands)

    Oikonomopoulou, F.; Bristogianni, T; Veer, F.A.; Nijsse, R.; da Sousa Cruz, Paulo J.

    In this paper a bundled glass column is presented as a promising solution for a completely transparent, almost dematerialized structural compressive element. The aim is to ob-tain a glass column that can safely carry loads, achieve a high visual result and be relatively eas-ily manufactured.

  3. Line bundles and flat connections

    Indian Academy of Sciences (India)

    /fulltext/pmsc/127/03/0547-0549. Keywords. Calabi–Yau threefold; torsion; cocompact lattice; unitary representation. Abstract. We prove that there are cocompact lattices Γ in S L ( 2 , C ) with the property that there are holomorphic line bundles ...

  4. Line bundles and flat connections

    Indian Academy of Sciences (India)

    Calabi–Yau threefold; torsion; cocompact lattice; unitary representation. 2000 Mathematics Subject Classification. 81T30, 14D21, 53C07. 1. Stable bundles and unitary flat connections. 1.1 Admitting flat connections. Let X be a compact connected complex manifold of complex dimension δ. Let ω be the. (1, 1)-form on X ...

  5. Chemical vapor infiltration in single fiber bundles

    Energy Technology Data Exchange (ETDEWEB)

    Devlin, D.J.; Barbero, R.S.; Currier, R.P.

    1990-01-01

    Chemical vapor infiltration (CVI) in single fiber bundles is studied under isothermal conditions. Understanding infiltration dynamics in single bundles is essential to process design and modeling efforts. Deposition of pyrolytic carbon in carbon-fiber bundles is chosen as the experimental system, with densification data obtained from thermogravimetric analysis. Data are then compared to predictions from a recently proposed CVI model for fiber bundle densification. 10 refs., 5 figs., 1 tab.

  6. Principal G-bundles on nodal curves

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    If Y is reducible these notions depend on parameters a = (a1,...,aI ). The study of G-bundles on Y is done by extending the notion of (generalized) parabolic vector bundles [U1] to generalized parabolic principal G-bundles (called GPGs in short) on the curve C and using the correspondence between them and principal ...

  7. Strategic and welfare implications of bundling

    DEFF Research Database (Denmark)

    Martin, Stephen

    1999-01-01

    A standard oligopoly model of bundling shows that bundling by a firm with a monopoly over one product has a strategic effect because it changes the substitution relationships between the goods among which consumers choose. Bundling in appropriate proportions is privately profitable, reduces rivals...

  8. The Atiyah bundle and connections on a principal bundle

    Indian Academy of Sciences (India)

    INDRANIL BISWAS. School of Mathematics, Tata Institute of Fundamental Research, Homi Bhabha Road,. Mumbai 400 005 .... (U) on A(EG)(U) and (U, g ⊕ Rd) defined by multiplication. Therefore, the sheaf A(EG) is locally free over FC∞. (M) of rank dim(g ⊕ Rd). Hence. A(EG) defines a C. ∞ vector bundle over M of rank ...

  9. Higher order jet prolongations type gauge natural bundles over vector bundles

    Directory of Open Access Journals (Sweden)

    Jan Kurek

    2004-05-01

    Full Text Available Let $rgeq 3$ and $mgeq 2$ be natural numbers and $E$ be a vector bundle with $m$-dimensional basis. We find all gauge natural bundles ``similar" to the $r$-jet prolongation bundle $J^rE$ of $E$. We also find all gauge natural bundles ``similar" to the vector $r$-tangent bundle $(J^r_{fl}(E,R_0^*$ of $E$.

  10. Multipath packet switch using packet bundling

    DEFF Research Database (Denmark)

    Berger, Michael Stubert

    2002-01-01

    The basic concept of packet bundling is to group smaller packets into larger packets based on, e.g., quality of service or destination within the packet switch. This paper presents novel applications of bundling in packet switching. The larger packets created by bundling are utilized to extend...... switching capacity by use of parallel switch planes. During the bundling operation, packets will experience a delay that depends on the actual implementation of the bundling and scheduling scheme. Analytical results for delay bounds and buffer size requirements are presented for a specific scheduling...

  11. Conformal Nets II: Conformal Blocks

    Science.gov (United States)

    Bartels, Arthur; Douglas, Christopher L.; Henriques, André

    2017-08-01

    Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

  12. Simultaneous His Bundle and Left Ventricular Pacing for Optimal Cardiac Resynchronization Therapy Delivery: Acute Hemodynamic Assessment by Pressure-Volume Loops.

    Science.gov (United States)

    Padeletti, Luigi; Pieragnoli, Paolo; Ricciardi, Giuseppe; Innocenti, Lisa; Checchi, Luca; Padeletti, Margherita; Michelucci, Antonio; Picariello, Francesco; Valsecchi, Sergio

    2016-05-01

    Previous studies have investigated the role of intrinsic conduction in optimizing cardiac resynchronization therapy. We investigated the role of fusing pacing-induced activation and intrinsic conduction in cardiac resynchronization therapy by evaluating the acute hemodynamic effects of simultaneous His-bundle (HIS) and left ventricular (LV) pacing. We studied 11 patients with systolic heart failure and left bundle-branch block scheduled for cardiac resynchronization therapy implantation. On implantation, LV pressure-volume data were determined via conductance catheter. Standard leads were placed in the right atrium, at the right ventricular apex, and in a coronary vein. An additional electrode was temporarily positioned in the HIS. The following pacing configurations were systematically assessed: standard biventricular (right ventricular apex+LV), LV-only, HIS, simultaneous HIS and LV (HIS+LV). Each configuration was compared with the AAI mode at multiple atrioventricular delays (AVD). In comparison with the AAI, right ventricular apex+LV and LV-only pacing resulted in improved stroke volume (85±32 mL and 86±33 mL versus 58±23 mL; PHIS-LV pacing improved hemodynamic indexes at all AVD (stroke volume >76 mL at all fixed intervals and 88±31 mL at optimal interval; all PHIS+LV pacing yielded improvements, regardless of AVD setting. These findings support the hypothesis of the crucial role of intrinsic right ventricular conduction in optimal cardiac resynchronization therapy delivery. © 2016 American Heart Association, Inc.

  13. Static stress analysis of CANFLEX fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Suk, Ho Chun; Kang, Hee Young; Sim, Ki Seop; Jeong, Jang Hwan; Jun, Gi Su; Park, Ju Hwan; Lee, Che Han; Kim, Tae Hyoung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-02-01

    The static stress analysis of CANFLEX bundles is performed to evaluate the fuel structural integrity during the refuelling service. The structure analysis is carried out by predicting the drag force, stress and displacements of the fuel bundle. By the comparison of strength tests and analysis results, the displacement values are well agreed within 15%. The analysis shows that the CANFLEX fuel bundle keep its structural integrity. 24 figs., 6 tabs., 12 refs. (Author) .new.

  14. Hydraulic characteristics of HANARO fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Cho, S.; Chung, H. J.; Chun, S. Y.; Yang, S. K.; Chung, M. K. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    This paper presents the hydraulic characteristics measured by using LDV (Laser Doppler Velocimetry) in subchannels of HANARO, KAERI research reactor, fuel bundle. The fuel bundle consists of 18 axially finned rods with 3 spacer grids, which are arranged in cylindrical configuration. The effects of the spacer grids on the turbulent flow were investigated by the experimental results. Pressure drops for each component of the fuel bundle were measured, and the friction factors of fuel bundle and loss coefficients for the spacer grids were estimated from the measured pressure drops. Implications regarding the turbulent thermal mixing were discussed. Vibration test results measured by using laser vibrometer were presented. 9 refs., 12 figs. (Author)

  15. Ulrich Schur bundles on flag varieties

    OpenAIRE

    Coskun, Izzet; Costa, Laura; Huizenga, Jack; Miró-Roig, Rosa Maria; Woolf, Matthew

    2015-01-01

    In this paper, we study equivariant vector bundles on partial flag varieties arising from Schur functors. We show that a partial flag variety with three or more steps does not admit an Ulrich bundle of this form with respect to the minimal ample class. We classify Ulrich bundles of this form on two-step flag varieties F(1,n-1;n), F(2,n-1;n), F(2,n-2;n), F(k,k+1;n) and F(k,k+2;n). We give a conjectural description of the two-step flag varieties which admit such Ulrich bundles.

  16. Equivariant Ulrich bundles on flag varieties

    OpenAIRE

    Coskun, Izzet; Huizenga, Jack; Woolf, Matthew

    2015-01-01

    In this paper, we study equivariant vector bundles on partial flag varieties arising from Schur functors. We show that a partial flag variety with three or more steps does not admit an Ulrich bundle of this form with respect to the minimal ample class. We classify Ulrich bundles of this form on two-step flag varieties F(2,n;n+1), F(2,n;n+2), F(k,k+1;n), and F(k,k+2;n). We give a conjectural description of the two-step flag varieties which admit such Ulrich bundles. Our results provide counter...

  17. His-Bundle Pacing for Identifying Optimal Ablation Sites in Patients Undergoing Atrioventricular Junction Ablation: Teaching an Old Dog a New Trick.

    Science.gov (United States)

    Kulkarni, Nitin; Moore, Curtiss; Pandey, Ambarish; Castillo, Demetrio; Ayers, Colby; Joglar, Jose; Wu, Richard

    2017-03-01

    Atrioventricular (AV) junction (AVJ) ablation is conventionally performed by localizing the His-bundle electrogram (HBE). Identification of HBE in the presence of atrial fibrillation (AF) can be difficult, and can make this simple procedure challenging. In this study, we describe our experience with an alternative approach to localize optimal ablation sites using His-bundle pacing (HBP). Between 1/1/2014 and 12/31/2015, we performed 13 AVJ ablations using the standard electrogram-guided approach and 11 ablations using HBP. All cases utilized a long femoral guiding sheath and an 8-mm-tip electrode radiofrequency (RF) energy ablation catheter. Pacing was performed at high output (10 mA at 2 ms) to initially achieve right bundle branch capture. The catheter was withdrawn until a narrow QRS morphology and increased stim-to-QRS time were observed. HBP was confirmed when paced and native QRS were identical in morphology. RF energy was applied at the site of HBP capture until AV block was observed. Baseline characteristics of patients in each arm were not significantly different. Compared with the standard approach, HBP was associated with trends toward lower RF applications (3 vs. 2, P = 0.16) and shorter mean RF time (208 seconds vs. 128 seconds, P = 0.19). HBP is an effective technique to identify optimal ablation sites during AVJ ablation and may shorten procedure time. HBP can be used to identify the AV node during AF without recording the His potential. Future studies with larger sample size are needed to better characterize the utility of this technique. © 2017 Wiley Periodicals, Inc.

  18. Combining living anionic polymerization with branching reactions in an iterative fashion to design branched polymers.

    Science.gov (United States)

    Higashihara, Tomoya; Sugiyama, Kenji; Yoo, Hee-Soo; Hayashi, Mayumi; Hirao, Akira

    2010-06-16

    This paper reviews the precise synthesis of many-armed and multi-compositional star-branched polymers, exact graft (co)polymers, and structurally well-defined dendrimer-like star-branched polymers, which are synthetically difficult, by a commonly-featured iterative methodology combining living anionic polymerization with branched reactions to design branched polymers. The methodology basically involves only two synthetic steps; (a) preparation of a polymeric building block corresponding to each branched polymer and (b) connection of the resulting building unit to another unit. The synthetic steps were repeated in a stepwise fashion several times to successively synthesize a series of well-defined target branched polymers. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Neuro-Oncology Branch

    Science.gov (United States)

    ... BTTC are experts in their respective fields. Neuro-Oncology Clinical Fellowship This is a joint program with ... can increase survival rates. Learn more... The Neuro-Oncology Branch welcomes Dr. Mark Gilbert as new Branch ...

  20. Branched polynomial covering maps

    DEFF Research Database (Denmark)

    Hansen, Vagn Lundsgaard

    1999-01-01

    A Weierstrass polynomial with multiple roots in certain points leads to a branched covering map. With this as the guiding example, we formally define and study the notion of a branched polynomial covering map. We shall prove that many finite covering maps are polynomial outside a discrete branch...... set. Particular studies are made of branched polynomial covering maps arising from Riemann surfaces and from knots in the 3-sphere....

  1. Branched polynomial covering maps

    DEFF Research Database (Denmark)

    Hansen, Vagn Lundsgaard

    2002-01-01

    A Weierstrass polynomial with multiple roots in certain points leads to a branched covering map. With this as the guiding example, we formally define and study the notion of a branched polynomial covering map. We shall prove that many finite covering maps are polynomial outside a discrete branch...... set. Particular studies are made of branched polynomial covering maps arising from Riemann surfaces and from knots in the 3-sphere. (C) 2001 Elsevier Science B.V. All rights reserved....

  2. Why (almost) all bundles are chiral

    Science.gov (United States)

    Kost-Smith, Zachary V.; Blackwell, Robert A.; Glaser, Matthew A.

    2014-03-01

    We examine the self assembly of bundles of achiral hard rods with distributed, short-range attractive interactions. We show that in the majority of cases the equilibrium state of the bundle is chiral, with a double twist structure. We use biased Monte Carlo techniques and cell theory to compute the free energy as a function of an appropriately defined twist order parameter, and show that the formation of spontaneously chiral bundles is driven by maximization of orientational entropy. The finite curvature of the bundle boundary permits orientational escape, in which the circumferential angular range of motion of the rods is maximized for some finite average tilt. We map out the phase diagram of bundles in terms of the density, the ratio of rod length to bundle radius, L / R , and rod aspect ratio, L / D , and find transitions between untwisted, weakly twisted, and strongly twisted states. This work helps explain the common observation of twisted macroscopic bundles, and may provide insight into observations of twist in self-assembled membranes of colloidal rods.[2] This work funded by NSF MRSEC Grant DMR-0820579.

  3. Second-Degree Interatrial Block in Hemodialysis Patients

    Science.gov (United States)

    Enriquez, Andres; D'Amato, Anna; de Luna, Antoni Bayes; Baranchuk, Adrian

    2015-01-01

    Interatrial conduction delays manifest as a prolonged P-wave duration on surface ECG and the term interatrial block (IAB) has been coined. They are usually fixed, but cases of intermittent IAB have been described, suggesting functional conduction block at the Bachmann bundle region. We report 2 cases of patients on chronic hemodialysis therapy presenting with intermittent IAB. PMID:25755895

  4. Second-Degree Interatrial Block in Hemodialysis Patients

    Directory of Open Access Journals (Sweden)

    Andres Enriquez

    2015-01-01

    Full Text Available Interatrial conduction delays manifest as a prolonged P-wave duration on surface ECG and the term interatrial block (IAB has been coined. They are usually fixed, but cases of intermittent IAB have been described, suggesting functional conduction block at the Bachmann bundle region. We report 2 cases of patients on chronic hemodialysis therapy presenting with intermittent IAB.

  5. Einstein metrics on tangent bundles of spheres

    Energy Technology Data Exchange (ETDEWEB)

    Dancer, Andrew S [Jesus College, Oxford University, Oxford OX1 3DW (United Kingdom); Strachan, Ian A B [Department of Mathematics, University of Hull, Hull HU6 7RX (United Kingdom)

    2002-09-21

    We give an elementary treatment of the existence of complete Kaehler-Einstein metrics with nonpositive Einstein constant and underlying manifold diffeomorphic to the tangent bundle of the (n+1)-sphere.

  6. Dynamic bi-product bundle pricing problem

    Directory of Open Access Journals (Sweden)

    Rafiei Hamed

    2014-01-01

    Full Text Available This paper addresses bundle pricing problem of two products in a stochastic environment so as to maximize net profit of a retailer. In the considered problem, it is assumed that customers are received upon a Poisson distribution and their demands follow a bi-variant distribution function. Also, it is assumed that products are sold individually or in the form of a bundle, which are offered from an initial stock of the products. To tackle the problem, a stochastic dynamic program is developed in which optimum values of the initial stock and order quantities of every planning period are determined. Moreover, prices of the individual products and their bundle are optimized. Also, the proposed dynamic program tackles bundling/ unbundling decisions taken in every planning period. A numerical example of a two planning period horizon is considered to validate the proposed model.

  7. Myocardial infarction, symptomatic third degree atrioventricular block and pulmonary embolism caused by thalidomide: a case report.

    Science.gov (United States)

    Zhang, Shengyu; Yang, Jing; Jin, Xiaofeng; Zhang, Shuyang

    2015-12-18

    Thalidomide has been reported to cause numerous thromboembolic events. Deep vein thrombosis and pulmonary embolism are more common. It can also cause bradycardia and even total atrioventricular block. Rarely, it causes coronary artery spasm and even myocardial infarction. But almost simultaneous onset of myocardial infarction, third degree atrioventricular block and pulmonary embolism in one patient has not been reported so far. A 53-year old man presented because of chest pain, nausea and then syncope for several minutes. Previous medical history included neurodermitis for which thalidomide was given and hypercholesterolemia with simvastatin taking. The patient didn't exhibit any other established risk factors for coronary artery disease. Electrocardiography showed sinus rhythm with third degree atrioventricular block and complete right bundle branch block, and precordial leads ST segment elevation. The diagnosis of acute coronary syndrome was suspected, but further coronary angiography demonstrated no flow-limiting lesions in coronary arteries, and temporary pacemaker was implanted. After admission, low SpO2 and elevated D-dimer level was mentioned. Further computed tomography pulmonary angiography revealed pulmonary embolism. Thalidomide was thought to be the cause of hypercoagulability and coronary spasm, so it was ceased immediately. Therapeutic low molecule weight heparin was initiated and then switched to warfarin with appropriate INR, and nifedipine was described for coronary spasm. The patient's symptoms completely relived and SpO2 recovered, and atrioventricular block had disappeared during hospitalization with pacemaker removed. This is the very first case in which myocardial infarction, third degree atrioventricular block and pulmonary embolism almost simultaneously developed. We should be ware that anti-thrombotic prophylaxis, which needs further investigation for optimal drug and dosage, may be beneficial in thalidomide therapy. And it is also

  8. Design and impact of bundled payment for detox and follow-up care.

    Science.gov (United States)

    Quinn, Amity E; Hodgkin, Dominic; Perloff, Jennifer N; Stewart, Maureen T; Brolin, Mary; Lane, Nancy; Horgan, Constance M

    2017-11-01

    under this bundled payment design, but many providers will lose money under a bundled payment designed using historic payment and costs. Designing a bundled payment for detox and follow-up care is feasible, but low case volume and the adequacy of the payment are concerns. Thus, a detox episode-based payment will likely be more challenging for smaller, independent SUD treatment providers. These providers are experiencing many changes as financing shifts away from block grant funding toward Medicaid funding. A detox bundled payment in practice would need to consider different risk mitigation strategies, provider pooling, and costs based on episodes of care meeting quality standards, but could incentivize care coordination, which is important to reducing detox readmissions and engaging patients in care. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Electrocardiogram: his bundle potentials can be recorded noninvasively beat by beat on surface electrocardiogram.

    Science.gov (United States)

    Wang, Gaopin; Liu, Renguang; Chang, Qinghua; Xu, Zhaolong; Zhang, Yingjie; Pan, Dianzhu

    2017-03-15

    The micro waveform of His bundle potential can't be recorded beat-to-beat on surface electrocardiogram yet. We have found that the micro-wavelets before QRS complex may be related to atrioventricular conduction system potentials. This study is to explore the possibility of His bundle potential can be noninvasively recorded on surface electrocardiogram. We randomized 65 patients undergoing radiofrequency catheter ablation of paroxysmal superventricular tachycardia (exclude overt Wolff-Parkinson-White syndrome) to receive "conventional electrocardiogram" and "new electrocardiogram" before the procedure. His bundle electrogram was collected during the procedure. Comparative analysis of PA s (PA interval recorded on surface electrocardiogram), AH s (AH interval recorded on surface electrocardiogram) and HV s (HV interval recorded on surface electrocardiogram) interval recorded on surface "new electrocardiogram" and PA, AH, HV interval recorded on His bundle electrogram was investigated. There was no difference (P > 0.05) between groups in HV s interval (49.63 ± 6.19 ms) and HV interval (49.35 ± 6.49 ms). Results of correlational analysis found that HV S interval was significantly positively associated with HV interval (r = 0.929; P electrocardiogram. Noninvasive His bundle potential tracing might represent a new method for locating the site of atrioventricular block and identifying the origin of a wide QRS complex.

  10. Biomechanics of the porcine triple bundle anterior cruciate ligament.

    Science.gov (United States)

    Kato, Yuki; Ingham, Sheila J M; Linde-Rosen, Monica; Smolinski, Patrick; Horaguchi, Takashi; Fu, Freddie H

    2010-01-01

    Several species of animals are used as a model to study human anterior cruciate ligament (ACL) reconstruction. In many animals, three bundles were clearly discernible during dissection in the ACL. However, there are few reports about the biomechanical role of each bundle in the porcine knee. The purpose of this study is to investigate the role of each of the three bundles in the porcine knee, especially the intermediate bundle. Ten porcine knees were tested using a robotic/universal forcemoment sensor system. This system applied anterior loading of 89 N at 30 degrees, 60 degrees and 90 degrees of flexion, and a combined 7 Nm valgus and 4 Nm internal tibial torque at 30 degrees and 60 degrees of flexion before and after each bundle was selectively cut. The in situ force (N) for each bundle of the ACL was measured. Both intermediate (IM) bundle and postero-lateral (PL) bundle had significantly lower in situ force than the antero-medial (AM) bundle in anterior loading. The IM and PL bundles carried a larger proportion of the force under the torsional loads than the anterior loads. But IM bundle had a significant lower in situ force during the combined torque at 60 degrees of knee flexion, when compared intact ACL. In summary, IM bundle has a subordinate role to the AM and PL bundles. AM bundle is more dominant than IM and PL bundles. The porcine knee is a suitable model for ACL studies, especially for AP stability.

  11. Stability of Picard bundle over moduli space of stable vector bundles ...

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    Stability of Picard bundle over moduli space of stable vector bundles of rank two over a curve. INDRANIL BISWAS and TOM ´AS L G ´OMEZ. School of Mathematics, Tata Institute of Fundamental Research, Homi Bhabha Road,. Mumbai 400 005, India. E-mail: indranil@math.tifr.res.in; tomas@math.tifr.res.in. MS received 14 ...

  12. Stability of Picard bundle over moduli space of stable vector bundles ...

    Indian Academy of Sciences (India)

    Abstract. Answering a question of [BV] it is proved that the Picard bundle on the moduli space of stable vector bundles of rank two, on a Riemann surface of genus at least three, with fixed determinant of odd degree is stable.

  13. Population Blocks.

    Science.gov (United States)

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  14. Coherent branching feature bisimulation

    Directory of Open Access Journals (Sweden)

    Tessa Belder

    2015-04-01

    Full Text Available Progress in the behavioral analysis of software product lines at the family level benefits from further development of the underlying semantical theory. Here, we propose a behavioral equivalence for feature transition systems (FTS generalizing branching bisimulation for labeled transition systems (LTS. We prove that branching feature bisimulation for an FTS of a family of products coincides with branching bisimulation for the LTS projection of each the individual products. For a restricted notion of coherent branching feature bisimulation we furthermore present a minimization algorithm and show its correctness. Although the minimization problem for coherent branching feature bisimulation is shown to be intractable, application of the algorithm in the setting of a small case study results in a significant speed-up of model checking of behavioral properties.

  15. Transient receptor potential melastatin 4 cation channel in pediatric heart block.

    Science.gov (United States)

    Tian, J; An, X-J; Fu, M-Y

    2017-10-01

    Progressive cardiac conduction disease (PCCD) is a common pediatric heart conduction disorder. It is an autosomal inheritance of rare mutations, which leads to familial cases of PCCD. In these cases, the His-Purkinje system's conductive capacity is progressively deranged, involving either right or left bundle branch block. Also, QRS complexes display widening is an important characteristic that culminates in complete AV block, syncope, and sudden death. Mutations in TRPM4 gene that encodes for transient receptor potential melastatin 4 have recently been reported to cause familial cases of PCCD and heart block. TRPM4 conducts a Ca2+-activated non-selective monovalent cationic current leading to a negative plasma membrane potential. TRPM4 channels let Na+ ion influx, causing membrane depolarization, whereas, at positive membrane potentials, TRPM4 channels repolarize the membrane by facilitating K+ ion efflux from the cell. TRPM4 protein contains many regulatory motifs that confer voltage dependence, ATP/ADP sensitivity, and Ca2+ responsiveness. Mutational studies revealed the significance of the two-calmodulin binding sites at the N-terminus of for Ca2+ dependent activation of this channel. Mutations that reduce deSUMOylation increase the steady-state levels of active TRPM4 channels on the membrane without alteration of its sensitivity to Ca2+ or ATP or its voltage dependence of activation. Increased TRPM4 function interferes with cardiac conduction and eventually contributes to heart block. Both gain and loss of function mutations of TRPM4 are implicated in the cardiac block. Currently, the major therapeutic management of cardiac block due to TRPM4 mutations is implantation of a pacemaker to reinstate normal current propagation through AV node.

  16. Renal Branch Artery Stenosis

    DEFF Research Database (Denmark)

    Andersson, Zarah; Thisted, Ebbe; Andersen, Ulrik Bjørn

    2017-01-01

    Renovascular hypertension is a common cause of pediatric hypertension. In the fraction of cases that are unrelated to syndromes such as neurofibromatosis, patients with a solitary stenosis on a branch of the renal artery are common and can be diagnostically challenging. Imaging techniques...... that perform well in the diagnosis of main renal artery stenosis may fall short when it comes to branch artery stenosis. We report 2 cases that illustrate these difficulties and show that a branch artery stenosis may be overlooked even by the gold standard method, renal angiography....

  17. Materials Test Branch

    Science.gov (United States)

    Gordon, Gail

    2012-01-01

    The Materials Test Branch resides at Marshall Space Flight Center's Materials and Processing laboratory and has a long history of supporting NASA programs from Mercury to the recently retired Space Shuttle. The Materials Test Branch supports its customers by supplying materials testing expertise in a wide range of applications. The Materials Test Branch is divided into three Teams, The Chemistry Team, The Tribology Team and the Mechanical Test Team. Our mission and goal is to provide world-class engineering excellence in materials testing with a special emphasis on customer service.

  18. Balance Ability and Proprioception after Single-Bundle, Single-Bundle Augmentation, and Double-Bundle ACL Reconstruction

    Directory of Open Access Journals (Sweden)

    Yubao Ma

    2014-01-01

    Full Text Available Purpose. The present study sought to determine the influences of single-bundle (SB, single-bundle augmentation (SBA, and double-bundle (DB reconstructions on balance ability and proprioceptive function. Methods. 67 patients who underwent a single- or double-bundle ACL reconstruction or a SBA using multistranded autologous hamstring tendons were included in this study with a 1-year follow-up. Body sway and knee kinesthesia (using the threshold to detect passive motion test (TTDPM were measured to indicate balance ability and proprioceptive function, respectively. Additionally, within-subject differences in anterior-posterior stability of the tibia and lower extremity muscle strength were evaluated before and after surgery. Results. At 6 and 12 months after surgery, DB reconstruction resulted in better balance and proprioceptive function than SB reconstruction (P<0.05. Although no significant difference was observed in balance ability or proprioceptive function between the SBA and DB reconstructions, knee stability was significantly better with SBA and DB reconstructions than SB reconstruction (P<0.05. No significant differences were found in quadriceps and hamstrings strength among the three reconstruction techniques. Conclusions. Our findings consider that joint stability, proprioceptive function, and balance ability were superior with SBA and DB reconstructions compared to SB reconstruction at 6 and 12 months after surgery.

  19. ECM-Stimulated Actin Bundle Formation in Embryonic Corneal Epithelia is Tyrosine Phosphorylation Dependent

    Science.gov (United States)

    SVOBODA, KATHY K.H.; ORLOW, DANIEL L.; CHU, CHIA LIN; REENSTRA, WENDE R.

    2009-01-01

    Previous studies demonstrated that corneal epithelial cells isolated without basal lamina respond to extracellular matrix (ECM) in an actin dependent manner; the basal cell surface flattens and the actin cortical mat reorganizes. We hypothesize that the actin reorganization is initiated by intracellular signaling mechanisms that includes tyrosine phoshporylation and activation of the Rho, MAP kinase, and PI3 kinase signal transduction pathways. Our goals were to develop a morphological assay to test this hypothesis by answering the following questions: 1) Do the actin bundle formations in the cortical mat have the same configuration in response to different ECM molecules? 2) What is the minimum time ECM molecules need to be in contact with the tissue for the actin to reorganize? 3) Will blocking tyrosine phosphorylation inhibit reorganization of the actin? 4) Are known signal transduction proteins phosphorylated in response to soluble matrix molecules? The actin cortical mat demonstrated distinct bundle configurations in the presence of different ECM molecules. Soluble fibronectin accumulated at the basal cell surfaces 75-fold over 30 min in a clustered pattern. The cells need contact with ECM for a minimum of 10 min to reform the actin bundles at 2 hr. In contrast, two substances that bind to heptahelical receptors to stimulate the Rho pathway, bombesin and lysophosphatidic acid, reorganized the actin bundles in 15–30 min. Focal adhesion kinase, p190 Rho-GAP, tensin, and paxillin were tyrosine phosphorylated in response to soluble fibronectin, type I collagen, or laminin 1. Erk-1, erk-2, and PI3 kinase were activated after 1 hr stimulation by type I collagen. Herbimycin A blocked actin reorganization induced by ECM molecules. In conclusion, we have developed two morphological assays to examine the response of corneal epithelial cells to ECM molecules. In addition, actin bundle reorganization involved tyrosine phosphorylation, MAP kinase, and PI3 kinase

  20. Branching processes in biology

    CERN Document Server

    Kimmel, Marek

    2015-01-01

    This book provides a theoretical background of branching processes and discusses their biological applications. Branching processes are a well-developed and powerful set of tools in the field of applied probability. The range of applications considered includes molecular biology, cellular biology, human evolution and medicine. The branching processes discussed include Galton-Watson, Markov, Bellman-Harris, Multitype, and General Processes. As an aid to understanding specific examples, two introductory chapters, and two glossaries are included that provide background material in mathematics and in biology. The book will be of interest to scientists who work in quantitative modeling of biological systems, particularly probabilists, mathematical biologists, biostatisticians, cell biologists, molecular biologists, and bioinformaticians. The authors are a mathematician and cell biologist who have collaborated for more than a decade in the field of branching processes in biology for this new edition. This second ex...

  1. Graph Bundling by Kernel Density Estimation

    NARCIS (Netherlands)

    Hurter, C.; Ersoy, O.; Telea, A.

    We present a fast and simple method to compute bundled layouts of general graphs. For this, we first transform a given graph drawing into a density map using kernel density estimation. Next, we apply an image sharpening technique which progressively merges local height maxima by moving the convolved

  2. Fluxes, bundle gerbes and 2-Hilbert spaces

    Science.gov (United States)

    Bunk, Severin; Szabo, Richard J.

    2017-10-01

    We elaborate on the construction of a prequantum 2-Hilbert space from a bundle gerbe over a 2-plectic manifold, providing the first steps in a programme of higher geometric quantisation of closed strings in flux compactifications and of M5-branes in C-fields. We review in detail the construction of the 2-category of bundle gerbes and introduce the higher geometrical structures necessary to turn their categories of sections into 2-Hilbert spaces. We work out several explicit examples of 2-Hilbert spaces in the context of closed strings and M5-branes on flat space. We also work out the prequantum 2-Hilbert space associated with an M-theory lift of closed strings described by an asymmetric cyclic orbifold of the SU(2) WZW model, providing an example of sections of a torsion gerbe on a curved background. We describe the dimensional reduction of M-theory to string theory in these settings as a map from 2-isomorphism classes of sections of bundle gerbes to sections of corresponding line bundles, which is compatible with the respective monoidal structures and module actions.

  3. The unintended consequences of bundled payments.

    Science.gov (United States)

    Weeks, William B; Rauh, Stephen S; Wadsworth, Eric B; Weinstein, James N

    2013-01-01

    Consensus is building that episode-based bundled payments can produce substantial Medicare savings, and the Center for Medicare & Medicaid Innovation's Bundled Payment Initiative endorses this concept. The program generates potential cost savings by reducing the historic cost of time-defined episodes of care, provided through a discount. Although bundled payments can reduce waste primarily in the postacute care setting, concerns arise that, in an effort to maintain income levels that are necessary to cover fixed costs, providers may change their behaviors to increase the volume of episodes. Such actions would mitigate the savings that Medicare might have accrued and may perpetuate the fee-for-service payment mechanism, with episodes of care becoming the new service. Although bundled payments have some advantages over the current reimbursement system, true cost-savings to Medicare will be realized only when the federal government addresses the use issue that underlies much of the waste inherent in the system and provides ample incentives to eliminate capacity and move toward capitation.

  4. Capacity efficiency of recovery request bundling

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Dittmann, Lars; Berger, Michael Stübert

    2010-01-01

    This paper presents a comparison of recovery methods in terms of capacity efficiency. In particular, a method where recovery requests are bundled towards the destination (Shortcut Span Protection) is evaluated against traditional recovery methods. Our simulation results show that Shortcut Span...

  5. Meromorphic connections on vector bundles over curves

    Indian Academy of Sciences (India)

    Descartes,. 67084 Strasbourg Cedex, France. *Correspond author. E-mail: indranil@math.tifr.res.in; heu@math.unistra.fr. MS received 17 July 2013; revised 20 October 2013. Abstract. We give a criterion for filtered vector bundles over curves to admit a ...

  6. Diversity in the organization of elastin bundles and intramembranous muscles in bat wings.

    Science.gov (United States)

    Cheney, Jorn A; Allen, Justine J; Swartz, Sharon M

    2017-04-01

    Unlike birds and insects, bats fly with wings composed of thin skin that envelops the bones of the forelimb and spans the area between the limbs, digits, and sometimes the tail. This skin is complex and unusual; it is thinner than typical mammalian skin and contains organized bundles of elastin and embedded skeletal muscles. These elements are likely responsible for controlling the shape of the wing during flight and contributing to the aerodynamic capabilities of bats. We examined the arrangement of two macroscopic architectural elements in bat wings, elastin bundles and wing membrane muscles, to assess the diversity in bat wing skin morphology. We characterized the plagiopatagium and dactylopatagium of 130 species from 17 families of bats using cross-polarized light imaging. This method revealed structures with distinctive relative birefringence, heterogeneity of birefringence, variation in size, and degree of branching. We used previously published anatomical studies and tissue histology to identify birefringent structures, and we analyzed their architecture across taxa. Elastin bundles, muscles, neurovasculature, and collagenous fibers are present in all species. Elastin bundles are oriented in a predominantly spanwise or proximodistal direction, and there are five characteristic muscle arrays that occur within the plagiopatagium, far more muscle than typically recognized. These results inform recent functional studies of wing membrane architecture, support the functional hypothesis that elastin bundles aid wing folding and unfolding, and further suggest that all bats may use these architectural elements for flight. All species also possess numerous muscles within the wing membrane, but the architecture of muscle arrays within the plagiopatagium varies among families. To facilitate present and future discussion of these muscle arrays, we refine wing membrane muscle nomenclature in a manner that reflects this morphological diversity. The architecture of the

  7. Anterior cruciate ligament reconstruction with double bundle versus single bundle: experimental study

    National Research Council Canada - National Science Library

    Roberto F. Mota e Albuquerque; Sandra Umeda Sasaki; Marco Martins Amatuzzi; Fabio Janson Angelini

    2007-01-01

    OBJECTIVE: To test an intra-articular reconstruction of the anterior cruciate ligament of the knee in 10 human cadavers by replacing 2 anterior cruciate ligament bundles, with the purpose of producing...

  8. Bundling revisited: substitute products and inter-firm discounts

    OpenAIRE

    Armstrong, Mark

    2010-01-01

    This paper extends the standard model of bundling to allow products to be substitutes and for products to be supplied by separate sellers. Whether integrated or separate, firms have an incentive to introduce bundling discounts when demand for the bundle is elastic relative to demand for stand-alone products. When products are partial substitutes, this typically gives an integrated firm a greater incentive to offer a bundle discount (relative to the standard model with additive preferences), w...

  9. Ablação de taquicardia ventricular idiopática com morfologia de bloqueio de ramo esquerdo localizada no tronco da artéria pulmonar Ablation of idiopathic ventricular tachycardia with left bundle-branch block morphology located in the pulmonary trunk

    Directory of Open Access Journals (Sweden)

    Luiz Roberto Leite

    2005-02-01

    Full Text Available Paciente de 26 anos, sem cardiopatia estrutural, apresentando palpitações e pré-síncopes devido à taquicardia ventricular não sustentada, foi submetida a estudo eletrofisiológico para tentativa de ablação do foco arritmogênico, usando-se como local, os critérios de mapeamento. Sem obter êxito com o mapeamento da via de saída do ventrículo direito, posicionou-se o cateter dentro da artéria pulmonar com mapeamento de foco satisfatório, eliminando a taquicardia tão logo iniciada a radiofreqüência. Durante seguimento de 14 meses, a paciente permanece assintomática, sem arritmia ao Holter e não nessecitando de drogas antiarrítmicas.We report the case of a 26-year-old female patient with palpitations and presyncopes due to nonsustained ventricular tachycardia, who had no structural heart disease. The patient underwent electrophysiological study in an attempt to ablate the arrhythmogenic focus, whose location was determined by using mapping criteria. Because mapping of the right ventricular outflow tract was not successful, the catheter was placed inside the pulmonary artery with satisfactory mapping of the arrhythmogenic focus, and tachycardia was eliminated as soon as radiofrequency was initiated. The patient has remained asymptomatic for 14 months, with no treatment with antiarrhythmic drugs, and no arrhythmias on serial 24-hour Holter.

  10. Reflood experiments in rod bundles with flow blockages due to clad ballooning

    Energy Technology Data Exchange (ETDEWEB)

    Moon, S.K.; Kim, J.; Kim, K.; Kim, B.J.; Park, J.K.; Youn, Y.J.; Choi, H.S.; Song, C.H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-07-15

    Clad ballooning and the resulting partial flow blockage are one of the major thermal-hydraulic concerns associated with the coolability of partially blocked cores during a loss-of-coolant accident (LOCA). Several in-pile tests have shown that fuel relocation causes a local power accumulation and a high thermal coupling between the clad and fuel debris in the ballooned regions. However, previous experiments in the 1980s did not take into account the fuel relocation phenomena and resulting local power increase in the ballooned regions. The present paper presents the results of systematic investigations on the coolability of rod bundles with flow blockages. The experiments were mainly performed in 5 x 5 rod bundles, 2 x 2 rod bundles and other test facilities. The experiments include a reflood heat transfer, single-phase convective heat transfer, flow redistributions phenomena, and droplet break-up behavior. The effects of the fuel relocation and resulting local power increase were investigated using a 5 x 5 rod bundle. The fuel relocation phenomena increase the peak cladding temperature.

  11. Compactifications of reductive groups as moduli stacks of bundles

    DEFF Research Database (Denmark)

    Martens, Johan; Thaddeus, Michael

    Let G be a reductive group. We introduce the moduli problem of "bundle chains" parametrizing framed principal G-bundles on chains of lines. Any fan supported in a Weyl chamber determines a stability condition on bundle chains. Its moduli stack provides an equivariant toroidal compactification of ...... studied by Losev-Manin....

  12. Turkish and Native English Academic Writers' Use of Lexical Bundles

    Science.gov (United States)

    Öztürk, Yusuf; Köse, Gül Durmusoglu

    2016-01-01

    Lexical bundles such as "on the other hand" and "as a result of" are extremely common and important in academic discourse. The appropriate use of lexical bundles typical of a specific academic discipline is important for writers and the absence of such bundles may not sound fluent and native-like. Recent studies (e.g. Adel…

  13. Quillen bundle and geometric prequantization of non-abelian ...

    Indian Academy of Sciences (India)

    In this paper we prequantize the moduli space of non-abelian vortices. We explicitly calculate the symplectic form arising from 2 metric and we construct a prequantum line bundle whose curvature is proportional to this symplectic form. The prequantum line bundle turns out to be Quillen's determinant line bundle with a ...

  14. Real parabolic vector bundles over a real curve

    Indian Academy of Sciences (India)

    weights are integral multiples of 1/N, and the category of real -equivariant vector bundles on (Y,σY ). ... The notion of parabolic vector bundles over a compact Riemann surface was introduced by Seshadri [4] and their .... stable. If F is a direct sum of stable vector bundles having the same slope, then F is called polystable.

  15. Geometry of torus bundles in integrable Hamiltonian systems

    NARCIS (Netherlands)

    Lukina, Olga

    2008-01-01

    Thesis is concerned with global properties of Lagrangian bundles, i.e. symplectic n-torus bundles, as these occur in integrable Hamiltonian systems. It treats obstructions to triviality and concerns with classification of such bundles, as well as with manifestations of global invariants in

  16. Synthesis of branched polysaccharides with tunable degree of branching

    NARCIS (Netherlands)

    Ciric, Jelena; Loos, Katja

    2013-01-01

    An in vitro enzyme-catalyzed tandem reaction using the enzymes phosphorylase b from rabbit muscle and Deinococcus geothermalis glycogen branching enzyme (Dg GBE) to obtain branched polyglucans with tunable degree of branching (2% divided by 13%) is presented. The tunable degree of branching is

  17. Bundling of harvesting residues and whole-trees and the treatment of bundles; Hakkuutaehteiden ja kokopuiden niputus ja nippujen kaesittely

    Energy Technology Data Exchange (ETDEWEB)

    Kaipainen, H.; Seppaenen, V.; Rinne, S.

    1996-12-31

    The conditions on which the bundling of the harvesting residues from spruce regeneration fellings would become profitable were studied. The calculations showed that one of the most important features was sufficient compaction of the bundle, so that the portion of the wood in the unit volume of the bundle has to be more than 40 %. The tests showed that the timber grab loader of farm tractor was insufficient for production of dense bundles. The feeding and compression device of the prototype bundler was constructed in the research and with this device the required density was obtained.The rate of compaction of the dry spruce felling residues was about 40 % and that of the fresh residues was more than 50 %. The comparison between the bundles showed that the calorific value of the fresh bundle per unit volume was nearly 30 % higher than that of the dry bundle. This means that the treatment of the bundles should be done of fresh felling residues. Drying of the bundles succeeded well, and the crushing and chipping tests showed that the processing of the bundles at the plant is possible. The treatability of the bundles was also excellent. By using the prototype, developed in the research, it was possible to produce a bundle of the fresh spruce harvesting residues, the diameter of which was about 50 cm and the length about 3 m, and the rate of compaction over 50 %. By these values the reduction target of the costs is obtainable

  18. Heart block

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/007658.htm Heart block To use the sharing features on this page, ... Date 4/16/2017 Updated by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of ...

  19. Non-abelian higher gauge theory and categorical bundle

    Science.gov (United States)

    Viennot, David

    2016-12-01

    A gauge theory is associated with a principal bundle endowed with a connection permitting to define horizontal lifts of paths. The horizontal lifts of surfaces cannot be defined into a principal bundle structure. An higher gauge theory is an attempt to generalize the bundle structure in order to describe horizontal lifts of surfaces. A such attempt is particularly difficult for the non-abelian case. Some structures have been proposed to realize this goal (twisted bundle, gerbes with connection, bundle gerbe, 2-bundle). Each of them uses a category in place of the total space manifold of the usual principal bundle structure. Some of them replace also the structure group by a category (more precisely a Lie crossed module viewed as a category). But the base space remains still a simple manifold (possibly viewed as a trivial category with only identity arrows). We propose a new principal categorical bundle structure, with a Lie crossed module as structure groupoid, but with a base space belonging to a bigger class of categories (which includes non-trivial categories), that we called affine 2-spaces. We study the geometric structure of the categorical bundles built on these categories (which are a more complicated structure than the 2-bundles) and the connective structures on these bundles. Finally we treat an example interesting for quantum dynamics which is associated with the Bloch wave operator theory.

  20. SIKAP KONSUMEN TERHADAP PRODUK BUNDLING AGRIBISNIS

    Directory of Open Access Journals (Sweden)

    Didi Junaedi

    2017-04-01

    implementation to Dekalb brand hybrid corn and Round-up brand herbicide. By analyzes how consumer attitudes toward buying intention in this regard farmers as buyer and retailers as products services. The data used is primary data. Primary data is obtained using 2 kind of respondents are retailers and farmers. The data obtained by distributed 30 questionnaires for retailers and 110 farmers in Grobogan. The descriptive statistic employed to analyzed data by using multiple linear regressions with t test, F test and coefficient of determination. The result showed that on retailers respondents attribute the product bundling has no significant influence to consumer buying intention but consumer attitudes significantly influence the buying intention. On the farmers respondents showed that attributes of the product bundling and consumer attitudes positive and significant influence to buying intention.

  1. Covariance and the hierarchy of frame bundles

    Science.gov (United States)

    Estabrook, Frank B.

    1987-01-01

    This is an essay on the general concept of covariance, and its connection with the structure of the nested set of higher frame bundles over a differentiable manifold. Examples of covariant geometric objects include not only linear tensor fields, densities and forms, but affinity fields, sectors and sector forms, higher order frame fields, etc., often having nonlinear transformation rules and Lie derivatives. The intrinsic, or invariant, sets of forms that arise on frame bundles satisfy the graded Cartan-Maurer structure equations of an infinite Lie algebra. Reduction of these gives invariant structure equations for Lie pseudogroups, and for G-structures of various orders. Some new results are introduced for prolongation of structure equations, and for treatment of Riemannian geometry with higher-order moving frames. The use of invariant form equations for nonlinear field physics is implicitly advocated.

  2. Client Provider Collaboration for Service Bundling

    Directory of Open Access Journals (Sweden)

    LETIA, I. A.

    2008-04-01

    Full Text Available The key requirement for a service industry organization to reach competitive advantages through product diversification is the existence of a well defined method for building service bundles. Based on the idea that the quality of a service or its value is given by the difference between expectations and perceptions, we draw the main components of a frame that aims to support the client and the provider agent in an active collaboration meant to co-create service bundles. Following e3-value model, we structure the supporting knowledge around the relation between needs and satisfying services. We deal with different perspectives about quality through an ontological extension of Value Based Argumentation. The dialog between the client and the provider takes the form of a persuasion whose dynamic object is the current best configuration. Our approach for building service packages is a demand driven approach, allowing progressive disclosure of private knowledge.

  3. State-set branching

    DEFF Research Database (Denmark)

    Jensen, Rune Møller; Veloso, Manuela M.; Bryant, Randal E.

    2008-01-01

    In this article, we present a framework called state-set branching that combines symbolic search based on reduced ordered Binary Decision Diagrams (BDDs) with best-first search, such as A* and greedy best-first search. The framework relies on an extension of these algorithms from expanding a sing...

  4. Tracheobronchial Branching Anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Min Ji; Kim, Young Tong; Jou, Sung Shick [Soonchunhyang University, Cheonan Hospital, Cheonan (Korea, Republic of); Park, A Young [Soonchunhyang University College of Medicine, Asan (Korea, Republic of)

    2010-04-15

    There are various congenital anomalies with respect to the number, length, diameter, and location of tracheobronchial branching patterns. The tracheobronchial anomalies are classified into two groups. The first one, anomalies of division, includes tracheal bronchus, cardiac bronchus, tracheal diverticulum, pulmonary isomerism, and minor variations. The second one, dysmorphic lung, includes lung agenesis-hypoplasia complex and lobar agenesis-aplasia complex

  5. Uncovering Ecosystem Service Bundles through Social Preferences

    Science.gov (United States)

    Martín-López, Berta; Iniesta-Arandia, Irene; García-Llorente, Marina; Palomo, Ignacio; Casado-Arzuaga, Izaskun; Amo, David García Del; Gómez-Baggethun, Erik; Oteros-Rozas, Elisa; Palacios-Agundez, Igone; Willaarts, Bárbara; González, José A.; Santos-Martín, Fernando; Onaindia, Miren; López-Santiago, Cesar; Montes, Carlos

    2012-01-01

    Ecosystem service assessments have increasingly been used to support environmental management policies, mainly based on biophysical and economic indicators. However, few studies have coped with the social-cultural dimension of ecosystem services, despite being considered a research priority. We examined how ecosystem service bundles and trade-offs emerge from diverging social preferences toward ecosystem services delivered by various types of ecosystems in Spain. We conducted 3,379 direct face-to-face questionnaires in eight different case study sites from 2007 to 2011. Overall, 90.5% of the sampled population recognized the ecosystem’s capacity to deliver services. Formal studies, environmental behavior, and gender variables influenced the probability of people recognizing the ecosystem’s capacity to provide services. The ecosystem services most frequently perceived by people were regulating services; of those, air purification held the greatest importance. However, statistical analysis showed that socio-cultural factors and the conservation management strategy of ecosystems (i.e., National Park, Natural Park, or a non-protected area) have an effect on social preferences toward ecosystem services. Ecosystem service trade-offs and bundles were identified by analyzing social preferences through multivariate analysis (redundancy analysis and hierarchical cluster analysis). We found a clear trade-off among provisioning services (and recreational hunting) versus regulating services and almost all cultural services. We identified three ecosystem service bundles associated with the conservation management strategy and the rural-urban gradient. We conclude that socio-cultural preferences toward ecosystem services can serve as a tool to identify relevant services for people, the factors underlying these social preferences, and emerging ecosystem service bundles and trade-offs. PMID:22720006

  6. Principal bundles on the projective line

    Indian Academy of Sciences (India)

    M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

    LetX be a complete nonsingular curve over the algebraic closurek ofk andGa reductive group over k. Let E → X be a principal G-bundle on X. E is said to be semistable if, for every reduction of structure group EP ⊂ E to a maximal parabolic subgroup P of G, we have degree EP (p) ≤ 0, where p is the Lie algebra of P and EP ...

  7. Abelian conformal field theory and determinant bundles

    DEFF Research Database (Denmark)

    Andersen, Jørgen Ellegaard; Ueno, K.

    2007-01-01

    are up to a scale the same as the curvature of the connections constructed in [14, 16]. We study the sewing construction for nodal curves and its explicit relation to the constructed connections. Finally we construct preferred holomorphic sections of these line bundles and analyze their behaviour near...... nodal curves. These results are used in [4] to construct modular functors form the conformal field theories given in [14, 16] by twisting with an appropriate factional power of this Abelian theory....

  8. Uncovering ecosystem service bundles through social preferences.

    Directory of Open Access Journals (Sweden)

    Berta Martín-López

    Full Text Available Ecosystem service assessments have increasingly been used to support environmental management policies, mainly based on biophysical and economic indicators. However, few studies have coped with the social-cultural dimension of ecosystem services, despite being considered a research priority. We examined how ecosystem service bundles and trade-offs emerge from diverging social preferences toward ecosystem services delivered by various types of ecosystems in Spain. We conducted 3,379 direct face-to-face questionnaires in eight different case study sites from 2007 to 2011. Overall, 90.5% of the sampled population recognized the ecosystem's capacity to deliver services. Formal studies, environmental behavior, and gender variables influenced the probability of people recognizing the ecosystem's capacity to provide services. The ecosystem services most frequently perceived by people were regulating services; of those, air purification held the greatest importance. However, statistical analysis showed that socio-cultural factors and the conservation management strategy of ecosystems (i.e., National Park, Natural Park, or a non-protected area have an effect on social preferences toward ecosystem services. Ecosystem service trade-offs and bundles were identified by analyzing social preferences through multivariate analysis (redundancy analysis and hierarchical cluster analysis. We found a clear trade-off among provisioning services (and recreational hunting versus regulating services and almost all cultural services. We identified three ecosystem service bundles associated with the conservation management strategy and the rural-urban gradient. We conclude that socio-cultural preferences toward ecosystem services can serve as a tool to identify relevant services for people, the factors underlying these social preferences, and emerging ecosystem service bundles and trade-offs.

  9. Uncovering ecosystem service bundles through social preferences.

    Science.gov (United States)

    Martín-López, Berta; Iniesta-Arandia, Irene; García-Llorente, Marina; Palomo, Ignacio; Casado-Arzuaga, Izaskun; Amo, David García Del; Gómez-Baggethun, Erik; Oteros-Rozas, Elisa; Palacios-Agundez, Igone; Willaarts, Bárbara; González, José A; Santos-Martín, Fernando; Onaindia, Miren; López-Santiago, Cesar; Montes, Carlos

    2012-01-01

    Ecosystem service assessments have increasingly been used to support environmental management policies, mainly based on biophysical and economic indicators. However, few studies have coped with the social-cultural dimension of ecosystem services, despite being considered a research priority. We examined how ecosystem service bundles and trade-offs emerge from diverging social preferences toward ecosystem services delivered by various types of ecosystems in Spain. We conducted 3,379 direct face-to-face questionnaires in eight different case study sites from 2007 to 2011. Overall, 90.5% of the sampled population recognized the ecosystem's capacity to deliver services. Formal studies, environmental behavior, and gender variables influenced the probability of people recognizing the ecosystem's capacity to provide services. The ecosystem services most frequently perceived by people were regulating services; of those, air purification held the greatest importance. However, statistical analysis showed that socio-cultural factors and the conservation management strategy of ecosystems (i.e., National Park, Natural Park, or a non-protected area) have an effect on social preferences toward ecosystem services. Ecosystem service trade-offs and bundles were identified by analyzing social preferences through multivariate analysis (redundancy analysis and hierarchical cluster analysis). We found a clear trade-off among provisioning services (and recreational hunting) versus regulating services and almost all cultural services. We identified three ecosystem service bundles associated with the conservation management strategy and the rural-urban gradient. We conclude that socio-cultural preferences toward ecosystem services can serve as a tool to identify relevant services for people, the factors underlying these social preferences, and emerging ecosystem service bundles and trade-offs.

  10. An analytical fiber bundle model for pullout mechanics of root bundles

    Science.gov (United States)

    Cohen, D.; Schwarz, M.; Or, D.

    2011-09-01

    Roots in soil contribute to the mechanical stability of slopes. Estimation of root reinforcement is challenging because roots form complex biological networks whose geometrical and mechanical characteristics are difficult to characterize. Here we describe an analytical model that builds on simple root descriptors to estimate root reinforcement. Root bundles are modeled as bundles of heterogeneous fibers pulled along their long axes neglecting root-soil friction. Analytical expressions for the pullout force as a function of displacement are derived. The maximum pullout force and corresponding critical displacement are either derived analytically or computed numerically. Key model inputs are a root diameter distribution (uniform, Weibull, or lognormal) and three empirical power law relations describing tensile strength, elastic modulus, and length of roots as functions of root diameter. When a root bundle with root tips anchored in the soil matrix is pulled by a rigid plate, a unique parameter, ?, that depends only on the exponents of the power law relations, dictates the order in which roots of different diameters break. If ? 1, large roots break first. When ? = 1, all fibers break simultaneously, and the maximum tensile force is simply the roots' mean force times the number of roots in the bundle. Based on measurements of root geometry and mechanical properties, the value of ? is less than 1, usually ranging between 0 and 0.7. Thus, small roots always fail first. The model shows how geometrical and mechanical characteristics of roots and root diameter distribution affect the pullout force, its maximum and corresponding displacement. Comparing bundles of roots that have similar mean diameters, a bundle with a narrow variance in root diameter will result in a larger maximum force and a smaller displacement at maximum force than a bundle with a wide diameter distribution. Increasing the mean root diameter of a bundle without changing the distribution's shape increases

  11. Esclerosis sistémica complicada con síncope y bloqueo AV completo Systemic sclerosis complicated with syncope and complete AV block

    Directory of Open Access Journals (Sweden)

    Francisco Femenía

    2010-10-01

    Full Text Available La esclerosis sistémica es una compleja enfermedad que afecta el tejido conectivo, el sistema vascular y el sistema inmunológico, y se caracteriza por fibrosis cutánea y de órganos viscerales. Los bloqueos de rama y los hemibloqueos se presentan en el 25 a 75% de los casos y constituyen predictores independientes de mortalidad. Los bloqueos auriculoventriculares de segundo o tercer grado son muy raros. Presentamos el caso de una mujer de 47 años de edad, con diagnóstico de esclerosis sistémica, quien presenta episodio sincopal secundario a bloqueo auriculoventricular completo con necesidad de implante de marcapasos definitivo.Systemic sclerosis is a complex disease that affects the connective tissue, the vascular system and the immune system. It typically produces skin and organ fibrosis. Cardiac bundle branch blocks and fascicular blocks occur in 25-75% of the cases and were found to be independent predictors of mortality. Second and third degree atrioventricular block are very rare. We present the case of a 47 year-old female with diagnosis of systemic sclerosis, presented with syncope secondary to complete atrioventricular block requiring permanent pacemaker implantation.

  12. Medial branch neurotomy in low back pain

    Energy Technology Data Exchange (ETDEWEB)

    Masala, Salvatore; Mammucari, Matteo; Simonetti, Giovanni [Interventional Radiology and Radiotherapy University ' ' Tor Vergata' ' , Department of Diagnostic and Molecular Imaging, Rome (Italy); Nano, Giovanni [Interventional Radiology and Radiotherapy University ' ' Tor Vergata' ' , Department of Diagnostic and Molecular Imaging, Rome (Italy); University ' ' Tor Vergata' ' , Department of Radiology, Rome (Italy); Marcia, Stefano [S. Giovanni di Dio Hospital, Department of Diagnostic and Molecular Imaging, Cagliari (Italy)

    2012-07-15

    This study aimed to assess the effectiveness of pulsed radiofrequency medial branch dorsal ramus neurotomy in patients with facet joint syndrome. From January 2008 to April 2010, 92 patients with facet joint syndrome diagnosed by strict inclusion criteria and controlled diagnostic blocks undergone medial branch neurotomy. We did not exclude patients with failed back surgery syndrome (FBSS). Electrodes (20G) with 5-mm active tip were placed under fluoroscopy guide parallel to medial branch. Patients were followed up by physical examination and by Visual Analog Scale and Oswestry Disability Index at 1, 6, and 12 months. In all cases, pain improvement was statistically significant and so quality of life. Three non-FBSS patients had to undergo a second neurotomy because of non-satisfactory pain decrease. Complications were reported in no case. Medial branch radiofrequency neurotomy has confirmed its well-established effectiveness in pain and quality of life improvement as long as strict inclusion criteria be fulfilled and nerve ablation be accomplished by parallel electrode positioning. This statement can be extended also to FBSS patients. (orig.)

  13. Tau leptonic branching ratios

    CERN Document Server

    Buskulic, Damir; De Bonis, I; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Odier, P; Pietrzyk, B; Ariztizabal, F; Chmeissani, M; Crespo, J M; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Gaitan, V; Garrido, L; Martínez, M; Orteu, S; Pacheco, A; Padilla, C; Palla, Fabrizio; Pascual, A; Perlas, J A; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Farilla, A; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Natali, S; Nuzzo, S; Ranieri, A; Raso, G; Romano, F; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Bonvicini, G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Engelhardt, A; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Jacobsen, R; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Markou, C; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Oest, T; Palazzi, P; Pater, J R; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wiedenmann, W; Wildish, T; Witzeling, W; Wotschack, J; Ajaltouni, Ziad J; Bardadin-Otwinowska, Maria; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rossignol, J M; Saadi, F; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Kyriakis, A; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Passalacqua, L; Rougé, A; Rumpf, M; Tanaka, R; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Delfino, M C; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Pepé-Altarelli, M; Dorris, S J; Halley, A W; ten Have, I; Knowles, I G; Lynch, J G; Morton, W T; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Smith, M G; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Braun, O; Geweniger, C; Graefe, G; Hanke, P; Hepp, V; Kluge, E E; Putzer, A; Rensch, B; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Colling, D J; Dornan, Peter J; Konstantinidis, N P; Moneta, L; Moutoussi, A; Nash, J; San Martin, G; Sedgbeer, J K; Stacey, A M; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Bowdery, C K; Brodbeck, T J; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Whelan, E P; Williams, M I; Galla, A; Greene, A M; Kleinknecht, K; Quast, G; Raab, J; Renk, B; Sander, H G; Wanke, R; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Thulasidas, M; Nicod, D; Payre, P; Rousseau, D; Talby, M; Abt, I; Assmann, R W; Bauer, C; Blum, Walter; Brown, D; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Jakobs, K; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Wolf, G; Alemany, R; Boucrot, J; Callot, O; Cordier, A; Courault, F; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Musolino, G; Nikolic, I A; Park, H J; Park, I C; Schune, M H; Simion, S; Veillet, J J; Videau, I; Abbaneo, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Rizzo, G; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Triggiani, G; Vannini, C; Verdini, P G; Walsh, J; Betteridge, A P; Blair, G A; Bryant, L M; Cerutti, F; Gao, Y; Green, M G; Johnson, D L; Medcalf, T; Mir, L M; Perrodo, P; Strong, J A; Bertin, V; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Edwards, M; Maley, P; Norton, P R; Thompson, J C; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Beddall, A; Booth, C N; Boswell, R; Cartwright, S L; Combley, F; Dawson, I; Köksal, A; Letho, M; Newton, W M; Rankin, C; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Feigl, E; Grupen, Claus; Lutters, G; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Ragusa, F; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Bellantoni, L; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Harton, J L; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Schmitt, M; Scott, I J; Sharma, V; Turk, J; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G

    1996-01-01

    A sample of 62249 \\tau-pair events is selected from data taken with the ALEPH detector in 1991, 1992 and 1993. The measurement of the branching fractions for \\tau decays into electrons and muons is presented with emphasis on the study of systematic effects from selection, particle identification and decay classification. Combined with the most recent ALEPH determination of the \\tau lifetime, these results provide a relative measurement of the leptonic couplings in the weak charged current for transverse W bosons.

  14. Simultaneous synthesis of anatase colloidal and multiple-branched rutile TiO{sub 2} nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Trong Tung; Duong, Ngoc Huyen [School of Engineering Physics, Hanoi University of Science and Technology, Hanoi (Viet Nam); Mai, Xuan Dung [Dept. of Chemistry, Hanoi Pedagogical University No2, Vinh Phuc (Viet Nam)

    2017-03-15

    Facile synthesis of titanium dioxide (TiO{sub 2} ) nanostructures with controllability over their cystallinity, dimensions, and shape is in demand for diverse optoelectronic applications. Anatase colloidal particles and precipitates of rutile bundles were synthesized simultaneously using HCl catalyzed sol–gel process with titanium tetrachloride as Ti precursor. The crystallinity and the morphology of these two separable TiO{sub 2} phases were studied by X-ray diffraction, Raman spectroscopy, and transmission electron microscopy. The results show that by varying HCl concentration during synthesis, dimensions of colloidal anatase can be tuned from spherical particles with a diameter of 2–5 nm to nanorods of dimension of 4 nm (width) × 14 nm (length). The rutile bundles whose size increased with aging time consisted of multiple branches with elongation along c-axis. Both anatase nanorods and rutile bundles can be applied as highly efficient photocatalysts or electron conduits.

  15. Influence of Bundle Diameter and Attachment Point on Kinematic Behavior in Double Bundle Anterior Cruciate Ligament Reconstruction Using Computational Model

    Directory of Open Access Journals (Sweden)

    Oh Soo Kwon

    2014-01-01

    Full Text Available A protocol to choose the graft diameter attachment point of each bundle has not yet been determined since they are usually dependent on a surgeon’s preference. Therefore, the influence of bundle diameters and attachment points on the kinematics of the knee joint needs to be quantitatively analyzed. A three-dimensional knee model was reconstructed with computed tomography images of a 26-year-old man. Based on the model, models of double bundle anterior cruciate ligament (ACL reconstruction were developed. The anterior tibial translations for the anterior drawer test and the internal tibial rotation for the pivot shift test were investigated according to variation of bundle diameters and attachment points. For the model in this study, the knee kinematics after the double bundle ACL reconstruction were dependent on the attachment point and not much influenced by the bundle diameter although larger sized anterior-medial bundles provided increased stability in the knee joint. Therefore, in the clinical setting, the bundle attachment point needs to be considered prior to the bundle diameter, and the current selection method of graft diameters for both bundles appears justified.

  16. Monopoles and Modifications of Bundles over Elliptic Curves

    Directory of Open Access Journals (Sweden)

    Andrey M. Levin

    2009-06-01

    Full Text Available Modifications of bundles over complex curves is an operation that allows one to construct a new bundle from a given one. Modifications can change a topological type of bundle. We describe the topological type in terms of the characteristic classes of the bundle. Being applied to the Higgs bundles modifications establish an equivalence between different classical integrable systems. Following Kapustin and Witten we define the modifications in terms of monopole solutions of the Bogomolny equation. We find the Dirac monopole solution in the case R × (elliptic curve. This solution is a three-dimensional generalization of the Kronecker series. We give two representations for this solution and derive a functional equation for it generalizing the Kronecker results. We use it to define Abelian modifications for bundles of arbitrary rank. We also describe non-Abelian modifications in terms of theta-functions with characteristic.

  17. Trivalent Cation Induced Bundle Formation of Filamentous fd Phages.

    Science.gov (United States)

    Korkmaz Zirpel, Nuriye; Park, Eun Jin

    2015-09-01

    Bacteriophages are filamentous polyelectrolyte viral rods infecting only bacteria. In this study, we investigate the bundle formation of fd phages with trivalent cations having different ionic radii (Al(3+) , La(3+) and Y(3+) ) at various phage and counterion concentrations, and at varying bundling times. Aggregated phage bundles were detected at relatively low trivalent counterion concentrations (1 mM). Although 10 mM and 100 mM Y(3+) and La(3+) treatments formed larger and more intertwined phage bundles, Al(3+) and Fe(3+) treatments lead to the formation of networking filaments. Energy dispersive X-ray spectroscopy (EDX) analyses confirmed the presence of C, N and O peaks on densely packed phage bundles. Immunofluorescence labelling and ELISA analyses with anti-p8 antibodies showed the presence of phage filaments after bundling. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Heat Transfer Analysis in Wire Bundles for Aerospace Vehicles

    Science.gov (United States)

    Rickman, S. L.; Iamello, C. J.

    2016-01-01

    Design of wiring for aerospace vehicles relies on an understanding of "ampacity" which refers to the current carrying capacity of wires, either, individually or in wire bundles. Designers rely on standards to derate allowable current flow to prevent exceedance of wire temperature limits due to resistive heat dissipation within the wires or wire bundles. These standards often add considerable margin and are based on empirical data. Commercial providers are taking an aggressive approach to wire sizing which challenges the conventional wisdom of the established standards. Thermal modelling of wire bundles may offer significant mass reduction in a system if the technique can be generalized to produce reliable temperature predictions for arbitrary bundle configurations. Thermal analysis has been applied to the problem of wire bundles wherein any or all of the wires within the bundle may carry current. Wire bundles present analytical challenges because the heat transfer path from conductors internal to the bundle is tortuous, relying on internal radiation and thermal interface conductance to move the heat from within the bundle to the external jacket where it can be carried away by convective and radiative heat transfer. The problem is further complicated by the dependence of wire electrical resistivity on temperature. Reduced heat transfer out of the bundle leads to higher conductor temperatures and, hence, increased resistive heat dissipation. Development of a generalized wire bundle thermal model is presented and compared with test data. The steady state heat balance for a single wire is derived and extended to the bundle configuration. The generalized model includes the effects of temperature varying resistance, internal radiation and thermal interface conductance, external radiation and temperature varying convective relief from the free surface. The sensitivity of the response to uncertainties in key model parameters is explored using Monte Carlo analysis.

  19. Isomonodromic Deformations and Very Stable Vector Bundles of Rank Two

    Science.gov (United States)

    Biswas, Indranil; Heu, Viktoria; Hurtubise, Jacques

    2017-12-01

    For the universal isomonodromic deformation of an irreducible logarithmic rank two connection over a smooth complex projective curve of genus at least two, consider the family of holomorphic vector bundles over curves underlying this universal deformation. In a previous work we proved that the vector bundle corresponding to a general parameter of this family is stable. Here we prove that the vector bundle corresponding to a general parameter is in fact very stable, meaning it does not admit any nonzero nilpotent Higgs field.

  20. Bundling Products and Services Through Modularization Strategies

    DEFF Research Database (Denmark)

    Bask, Anu; Hsuan, Juliana; Rajahonka, Mervi

    2012-01-01

    Modularity has been recognized as a powerful tool in improving the efficiency and management of product design and manufacturing. However, the integrated view on covering both, product and service modularity for product-service systems (PSS), is under researched. Therefore, in this paper our...... objective is to contribute to the PSS modularity. Thus, we describe configurations of PSSs and the bundling of products and services through modularization strategies. So far there have not been tools to analyze and determine the correct combinations of degrees of product and service modularities....

  1. Differential geometry bundles, connections, metrics and curvature

    CERN Document Server

    Taubes, Clifford Henry

    2011-01-01

    Bundles, connections, metrics and curvature are the 'lingua franca' of modern differential geometry and theoretical physics. This book will supply a graduate student in mathematics or theoretical physics with the fundamentals of these objects. Many of the tools used in differential topology are introduced and the basic results about differentiable manifolds, smooth maps, differential forms, vector fields, Lie groups, and Grassmanians are all presented here. Other material covered includes the basic theorems about geodesics and Jacobi fields, the classification theorem for flat connections, the

  2. Affine Flag Manifolds and Principal Bundles

    CERN Document Server

    Schmitt, Alexander HW

    2010-01-01

    Affine flag manifolds are infinite dimensional versions of familiar objects such as Gramann varieties. The book features lecture notes, survey articles, and research notes - based on workshops held in Berlin, Essen, and Madrid - explaining the significance of these and related objects (such as double affine Hecke algebras and affine Springer fibers) in representation theory (e.g., the theory of symmetric polynomials), arithmetic geometry (e.g., the fundamental lemma in the Langlands program), and algebraic geometry (e.g., affine flag manifolds as parameter spaces for principal bundles). Novel

  3. Vector bundles on complex projective spaces

    CERN Document Server

    Okonek, Christian; Spindler, Heinz

    1980-01-01

    This expository treatment is based on a survey given by one of the authors at the Séminaire Bourbaki in November 1978 and on a subsequent course held at the University of Göttingen. It is intended to serve as an introduction to the topical question of classification of holomorphic vector bundles on complex projective spaces, and can easily be read by students with a basic knowledge of analytic or algebraic geometry. Short supplementary sections describe more advanced topics, further results, and unsolved problems.

  4. Enthalpy and void distributions in subchannels of PHWR fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. W.; Choi, H.; Rhee, B. W. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    Two different types of the CANDU fuel bundles have been modeled for the ASSERT-IV code subchannel analysis. From calculated values of mixture enthalpy and void fraction distribution in the fuel bundles, it is found that net buoyancy effect is pronounced in the central region of the DUPIC fuel bundle when compared with the standard CANDU fuel bundle. It is also found that the central region of the DUPIC fuel bundle can be cooled more efficiently than that of the standard fuel bundle. From the calculated mixture enthalpy distribution at the exit of the fuel channel, it is found that the mixture enthalpy and void fraction can be highest in the peripheral region of the DUPIC fuel bundle. On the other hand, the enthalpy and the void fraction were found to be highest in the central region of the standard CANDU fuel bundle at the exit of the fuel channel. This study shows that the subchannel analysis is very useful in assessing thermal behavior of the fuel bundle that could be used in CANDU reactors. 10 refs., 4 figs., 2 tabs. (Author)

  5. Thermal Energy Conversion Branch

    Science.gov (United States)

    Bielozer, Matthew C.; Schreiber, Jeffrey, G.; Wilson, Scott D.

    2004-01-01

    The Thermal Energy Conversion Branch (5490) leads the way in designing, conducting, and implementing research for the newest thermal systems used in space applications at the NASA Glenn Research Center. Specifically some of the most advanced technologies developed in this branch can be broken down into four main areas: Dynamic Power Systems, Primary Solar Concentrators, Secondary Solar Concentrators, and Thermal Management. Work was performed in the Dynamic Power Systems area, specifically the Stirling Engine subdivision. Today, the main focus of the 5490 branch is free-piston Stirling cycle converters, Brayton cycle nuclear reactors, and heat rejection systems for long duration mission spacecraft. All space exploring devices need electricity to operate. In most space applications, heat energy from radioisotopes is converted to electrical power. The Radioisotope Thermoelectric Generator (RTG) already supplies electricity for missions such as the Cassini Spacecraft. The focus of today's Stirling research at GRC is aimed at creating an engine that can replace the RTG. The primary appeal of the Stirling engine is its high system efficiency. Because it is so efficient, the Stirling engine will significantly reduce the plutonium fuel mission requirements compared to the RTG. Stirling is also being considered for missions such as the lunar/Mars bases and rovers. This project has focused largely on Stirling Engines of all types, particularly the fluidyne liquid piston engine. The fluidyne was developed by Colin D. West. This engine uses the same concepts found in any type of Stirling engine, with the exception of missing mechanical components. All the working components are fluid. One goal was to develop and demonstrate a working Stirling Fluidyne Engine at the 2nd Annual International Energy Conversion Engineering Conference in Providence, Rhode Island.

  6. A Hybrid Approach of Bundle and Benders Applied Large Mixed Linear Integer Problem

    Directory of Open Access Journals (Sweden)

    Placido Rogerio Pinheiro

    2013-01-01

    Full Text Available Consider a large mixed integer linear problem where structure of the constraint matrix is sparse, with independent blocks, and coupling constraints and variables. There is one of the groups of constraints to make difficult the application of Benders scheme decomposition. In this work, we propose the following algorithm; a Lagrangian relaxation is made on the mentioned set of constraints; we presented a process heuristic for the calculation of the multiplier through the resolution of the dual problem, structured starting from the bundle methods. According to the methodology proposed, for each iteration of the algorithm, we propose Benders decomposition where quotas are provided for the value function and ε-subgradient.

  7. The branch librarians' handbook

    CERN Document Server

    Rivers, Vickie

    2004-01-01

    ""Recommended""--Booklist; ""an excellent addition...highly recommended""--Public Libraries; ""clear...very sound advice...strongly recommend""--Catholic Library World; ""excellent resource...organized...well written""--Against the Grain; ""interesting...thoroughly practical...a very good book...well organized...clearly written""--ARBA. This handbook covers a wide variety of issues that the branch librarian must deal with every day. Chapters are devoted to mission statements (the Dallas Public Library and Dayton Metro Library mission statements are highlighted as examples), library systems,

  8. Flight Dynamics Analysis Branch

    Science.gov (United States)

    Stengle, Tom; Flores-Amaya, Felipe

    2000-01-01

    This report summarizes the major activities and accomplishments carried out by the Flight Dynamics Analysis Branch (FDAB), Code 572, in support of flight projects and technology development initiatives in fiscal year 2000. The report is intended to serve as a summary of the type of support carried out by the FDAB, as well as a concise reference of key accomplishments and mission experience derived from the various mission support roles. The primary focus of the FDAB is to provide expertise in the disciplines of flight dynamics, spacecraft trajectory, attitude analysis, and attitude determination and control. The FDAB currently provides support for missions and technology development projects involving NASA, government, university, and private industry.

  9. Pathology of complete atrioventricular block in chronic chagas' myocarditis

    Directory of Open Access Journals (Sweden)

    Zilton A. Andrade

    1988-03-01

    Full Text Available Sclero-atrophy, fibrosis, vascular ectasia, phlebosclerosis and mild non-specific chronic inflammatory changes were observed in variable location and proportion involving the atrioventricular conducting tissue of the heart in five human cases of chronic Chagas' myocarditis associated with complete atrioventricular block. One case presented complete destruction of the A-V conduction system. In three cases the lesions were disseminated all along the conducting tissue but did not cause anywhere a complete disruption in the continuity of the system. The distal portion of the bundle branches were the most damaged sector of the system, exceptfor the fasciculi of the posterior division of the left bundle branch which were relatively preserved. One case exhibited bilateral sclero-atrophy of the bundle branches as the main change; and another showed early and mild fibrocalcific damage of the penetrating portion of the His bundle. The A-V node appeared as the least involved part of the conducting system in the cases studied. Demonstration of the lesions in this series of cases seems important because: a it reveals that complete atrioventriculr block in chronic Chagas' disease results from disseminated lesions and not from focal disruptive change as has been commonly observed in cases of other etiologies; b it shows that chronic inflammation can produce at the end variable and widespread vascular, degenerative andfibrotic alterations within the conducting tissue of the heart, which may lead to its total destruction.O estudo do sistema de condução atrioventricular através cortes seriados completos em cinco casos humanos de miocardite crônica chagásica e bloqueio A-V total revelou a presença de lesões de esclero-atrofia, fibrose, ectasia vascular, fleboesclerose e inflamação crônica inespeclfica envolvendo o sistema de maneira disseminada, mas com distribuição e intensidade variáveis de caso para caso. Em um caso, todo o sistema, do nódulo A

  10. Molybdenum-99-producing 37-element fuel bundle neutronically and thermal-hydraulically equivalent to a standard CANDU fuel bundle

    Energy Technology Data Exchange (ETDEWEB)

    Nichita, E., E-mail: Eleodor.Nichita@uoit.ca; Haroon, J., E-mail: Jawad.Haroon@uoit.ca

    2016-10-15

    Highlights: • A 37-element fuel bundle modified for {sup 99}Mo production in CANDU reactors is presented. • The modified bundle is neutronically and thermal-hydraulically equivalent to the standard bundle. • The modified bundle satisfies all safety criteria satisfied by the standard bundle. - Abstract: {sup 99m}Tc, the most commonly used radioisotope in diagnostic nuclear medicine, results from the radioactive decay of {sup 99}Mo which is currently being produced at various research reactors around the globe. In this study, the potential use of CANDU power reactors for the production of {sup 99}Mo is investigated. A modified 37-element fuel bundle, suitable for the production of {sup 99}Mo in existing CANDU-type reactors is proposed. The new bundle is specifically designed to be neutronically and thermal-hydraulically equivalent to the standard 37-element CANDU fuel bundle in normal, steady-state operation and, at the same time, be able to produce significant quantities of {sup 99}Mo when irradiated in a CANDU reactor. The proposed bundle design uses fuel pins consisting of a depleted-uranium centre surrounded by a thin layer of low-enriched uranium. The new molybdenum-producing bundle is analyzed using the lattice transport code DRAGON and the diffusion code DONJON. The proposed design is shown to produce 4081 six-day Curies of {sup 99}Mo activity per bundle when irradiated in the peak-power channel of a CANDU core, while maintaining the necessary reactivity and power rating limits. The calculated {sup 99}Mo yield corresponds to approximately one third of the world weekly demand. A production rate of ∼3 bundles per week can meet the global demand of {sup 99}Mo.

  11. Design and evaluate finned tube bundles

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. [ABCO Industries, Abilene, TX (United States)

    1996-09-01

    Finned tube bundles are widely used in heat exchangers, air coolers, waste heat boilers and fired heaters where energy transfer occurs between clean flue gases and a fluid with a high heat-transfer coefficient. They have several advantages including compactness, low gas pressure drop and low weight for a given duty compared to bare tube bundles. Choosing a fin type, arrangement and fin configuration requires a thorough analysis and economic evaluation. The solution is not unique since it depends on material and labor costs. Surface areas vary widely in finned tube designs for the same duty and gas pressure drop. Therefore, decisions should not be based on surface area alone. Plant engineers and consultants should consider operating costs in their evaluation because they accrue year after year. Selecting a boiler based on initial costs alone is not prudent. The paper discusses heat transfer and gas pressure drop with finned tubes, determining fin efficiency and effectiveness,g as pressure drop, tube wall and fin top temperatures, an example calculation, the effect of fin configuration on design, the effect of inline versus staggered arrangements and solid versus serrated fins, and concerns with high fin-density designs.

  12. Development boiling to sprinkled tube bundle

    Directory of Open Access Journals (Sweden)

    Kracík Petr

    2016-01-01

    Full Text Available This paper presents results of a studied heat transfer coefficient at the surface of a sprinkled tube bundle where boiling occurs. Research in the area of sprinkled exchangers can be divided into two major parts. The first part is research on heat transfer and determination of the heat transfer coefficient at sprinkled tube bundles for various liquids, whether boiling or not. The second part is testing of sprinkle modes for various tube diameters, tube pitches and tube materials and determination of individual modes’ interface. All results published so far for water as the falling film liquid apply to one to three tubes for which the mentioned relations studied are determined in rigid laboratory conditions defined strictly in advance. The sprinkled tubes were not viewed from the operational perspective where there are more tubes and various modes may occur in different parts with various heat transfer values. The article focuses on these processes. The tube is located in a low-pressure chamber where vacuum is generated using an exhauster via ejector. The tube consists of smooth copper tubes of 12 mm diameter placed horizontally one above another.

  13. SHERLOCK 3CG™ Diamond Tip Confirmation System

    Science.gov (United States)

    2018-02-06

    Indication for Peripheral Intravenous Catheterization; Atrial Flutter; Premature Atrial Contraction; Premature Ventricular Contraction; Premature Junctional Contraction; Tachycardia; Atrioventricular Block; Bundle-Branch Block

  14. 29 CFR Appendix A to Subpart T to... - Examples of Conditions Which May Restrict or Limit Exposure to Hyperbaric Conditions

    Science.gov (United States)

    2010-07-01

    ...., pathological heart block, valvular disease, intraventricular conduction defects other than isolated right bundle branch block, angina pectoris, arrhythmia, coronary artery disease). Juxta-articular osteonecrosis. ...

  15. Evaluation of Single-Bundle versus Double-Bundle PCL Reconstructions with More Than 10-Year Follow-Up

    Directory of Open Access Journals (Sweden)

    Masataka Deie

    2015-01-01

    Full Text Available Background. Posterior cruciate ligament (PCL injuries are not rare in acute knee injuries, and several recent anatomical studies of the PCL and reconstructive surgical techniques have generated improved patient results. Now, we have evaluated PCL reconstructions performed by either the single-bundle or double-bundle technique in a patient group followed up retrospectively for more than 10 years. Methods. PCL reconstructions were conducted using the single-bundle (27 cases or double-bundle (13 cases method from 1999 to 2002. The mean age at surgery was 34 years in the single-bundle group and 32 years in the double-bundle group. The mean follow-up period was 12.5 years. Patients were evaluated by Lysholm scoring, the gravity sag view, and knee arthrometry. Results. The Lysholm score after surgery was 89.1±5.6 points for the single-bundle group and 91.9±4.5 points for the double-bundle group. There was no significant difference between the methods in the side-to-side differences by gravity sag view or knee arthrometer evaluation, although several cases in both groups showed a side-to-side difference exceeding 5 mm by the latter evaluation method. Conclusions. We found no significant difference between single- and double-bundle PCL reconstructions during more than 10 years of follow-up.

  16. Structure of building blocks in amylopectins.

    Science.gov (United States)

    Bertoft, Eric; Koch, Kristine; Man, Per

    2012-11-01

    Building blocks represent the smallest, branched units found inside clusters of amylopectins. The building blocks from clusters of 10 different amylopectins, representing a wide variety of plants, were isolated and size-fractionated. The unit chain compositions were then analysed. It was found that the number of chains in building blocks increased in proportion to their size similarly in all samples regardless plant source. The smallest blocks (DP 5-9) consisted of 2 chains and the largest blocks (DP ≥45), of which generally only little existed, possessed ≥10 chains. Generally, the degree of branching increased with building block size, but the organisation of chains inside the blocks was unique for each sample. Nevertheless, compared to other plants, amylopectins from cereals (represented by rye, oats, rice and waxy maize) possessing elevated number of the shortest internal B-chains (DP 3-7), tended to have blocks with a lower ratio of A:B-chains, indicative of a preferred Haworth type of structure as opposed to the Staudinger configuration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. An integral Riemann-Roch theorem for surface bundles

    DEFF Research Database (Denmark)

    Madsen, Ib Henning

    2010-01-01

    This paper is a response to a conjecture by T. Akita about an integral Riemann–Roch theorem for surface bundles.......This paper is a response to a conjecture by T. Akita about an integral Riemann–Roch theorem for surface bundles....

  18. Restriction Theorem for Principal bundles in Arbitrary Characteristic

    DEFF Research Database (Denmark)

    Gurjar, Sudarshan

    2015-01-01

    The aim of this paper is to prove two basic restriction theorem for principal bundles on smooth projective varieties in arbitrary characteristic generalizing the analogues theorems of Mehta-Ramanathan for vector bundles. More precisely, let G be a reductive algebraic group over an algebraically c...

  19. Phase Space Reduction of Star Products on Cotangent Bundles.

    NARCIS (Netherlands)

    Kowalzig, N.; Neumaier, N.; Pflaum, M.

    2005-01-01

    In this paper we construct star products on Marsden-Weinstein reduced spaces in case both the original phase space and the reduced phase space are (symplectomorphic to) cotangent bundles. Under the assumption that the original cotangent bundle $T^*Q$ carries a symplectic structure of form

  20. Monoubiquitination Inhibits the Actin Bundling Activity of Fascin.

    Science.gov (United States)

    Lin, Shengchen; Lu, Shuang; Mulaj, Mentor; Fang, Bin; Keeley, Tyler; Wan, Lixin; Hao, Jihui; Muschol, Martin; Sun, Jianwei; Yang, Shengyu

    2016-12-30

    Fascin is an actin bundling protein that cross-links individual actin filaments into straight, compact, and stiff bundles, which are crucial for the formation of filopodia, stereocillia, and other finger-like membrane protrusions. The dysregulation of fascin has been implicated in cancer metastasis, hearing loss, and blindness. Here we identified monoubiquitination as a novel mechanism that regulates fascin bundling activity and dynamics. The monoubiquitination sites were identified to be Lys247 and Lys250, two residues located in a positive charge patch at the actin binding site 2 of fascin. Using a chemical ubiquitination method, we synthesized chemically monoubiquitinated fascin and determined the effects of monoubiquitination on fascin bundling activity and dynamics. Our data demonstrated that monoubiquitination decreased the fascin bundling EC50, delayed the initiation of bundle assembly, and accelerated the disassembly of existing bundles. By analyzing the electrostatic properties on the solvent-accessible surface of fascin, we proposed that monoubiquitination introduced steric hindrance to interfere with the interaction between actin filaments and the positively charged patch at actin binding site 2. We also identified Smurf1 as a E3 ligase regulating the monoubiquitination of fascin. Our findings revealed a previously unidentified regulatory mechanism for fascin, which will have important implications for the understanding of actin bundle regulation under physiological and pathological conditions. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. Lexical Bundles in L1 and L2 Academic Writing

    Science.gov (United States)

    Chen, Yu-Hua; Baker, Paul

    2010-01-01

    This paper adopts an automated frequency-driven approach to identify frequently-used word combinations (i.e., "lexical bundles") in academic writing. Lexical bundles retrieved from one corpus of published academic texts and two corpora of student academic writing (one L1, the other L2), were investigated both quantitatively and qualitatively.…

  2. Lexical Bundles: Facilitating University "Talk" in Group Discussions

    Science.gov (United States)

    Heng, Chan Swee; Kashiha, Hadi; Tan, Helen

    2014-01-01

    Group discussion forms an integral language experience for most language learners, providing them with an opportunity to express themselves in a naturalistic setting. Multi-word expressions are commonly used and one of them is lexical bundles. Lexical bundles are types of extended collocations that occur more commonly than we expect; they are…

  3. A novel microbond bundle pullout technique to evaluate the ...

    Indian Academy of Sciences (India)

    2017-07-26

    Jul 26, 2017 ... to be a need to develop a microbond bundle pullout test that is comparable in all aspects to the semi-empirical resin slab/fibre bundle pullout approach [9]. The improvement of the known draw backs of the single fibre microbond pullout method [7], such as the difficulty in formulation and testing (with lack.

  4. Hair bundles are specialized for ATP delivery via creatine kinase.

    NARCIS (Netherlands)

    Shin, J.B.; Streijger, F.; Beynon, A.J.; Peters, T.; Gadzala, L.; McMillen, D.; Bystrom, C.; Zee, C.E.E.M. van der; Wallimann, T.; Gillespie, P.G.

    2007-01-01

    When stimulated strongly, a hair cell's mechanically sensitive hair bundle may consume ATP too rapidly for replenishment by diffusion. To provide a broad view of the bundle's protein complement, including those proteins participating in energy metabolism, we used shotgun mass spectrometry methods to

  5. Smooth Bundling of Large Streaming and Sequence Graphs

    NARCIS (Netherlands)

    Hurter, C.; Ersoy, O.; Telea, A.

    2013-01-01

    Dynamic graphs are increasingly pervasive in modern information systems. However, understanding how a graph changes in time is difficult. We present here two techniques for simplified visualization of dynamic graphs using edge bundles. The first technique uses a recent image-based graph bundling

  6. Computational imaging through a fiber-optic bundle

    Science.gov (United States)

    Lodhi, Muhammad A.; Dumas, John Paul; Pierce, Mark C.; Bajwa, Waheed U.

    2017-05-01

    Compressive sensing (CS) has proven to be a viable method for reconstructing high-resolution signals using low-resolution measurements. Integrating CS principles into an optical system allows for higher-resolution imaging using lower-resolution sensor arrays. In contrast to prior works on CS-based imaging, our focus in this paper is on imaging through fiber-optic bundles, in which manufacturing constraints limit individual fiber spacing to around 2 μm. This limitation essentially renders fiber-optic bundles as low-resolution sensors with relatively few resolvable points per unit area. These fiber bundles are often used in minimally invasive medical instruments for viewing tissue at macro and microscopic levels. While the compact nature and flexibility of fiber bundles allow for excellent tissue access in-vivo, imaging through fiber bundles does not provide the fine details of tissue features that is demanded in some medical situations. Our hypothesis is that adapting existing CS principles to fiber bundle-based optical systems will overcome the resolution limitation inherent in fiber-bundle imaging. In a previous paper we examined the practical challenges involved in implementing a highly parallel version of the single-pixel camera while focusing on synthetic objects. This paper extends the same architecture for fiber-bundle imaging under incoherent illumination and addresses some practical issues associated with imaging physical objects. Additionally, we model the optical non-idealities in the system to get lower modelling errors.

  7. Frobenius pull backs of vector bundles in higher dimensions

    Indian Academy of Sciences (India)

    Frobenius pull backs; instability degree, vector bundles. 1. Introduction. Let X be a nonsingular projective variety defined over an algebraically closed field k of an arbitrary characteristic, and let H be a very ample line bundle on X. Let E be a torsion free sheaf on X. Then the notion of E being stable (resp. semistable) is well- ...

  8. On Harder–Narasimhan reductions for Higgs principal bundles

    Indian Academy of Sciences (India)

    in Ramanathan's paper. The aim of this paper is to generalize the methods of Biswas and Holla to give a unified approach to the case of principal bundles with Higgs structure on smooth projective varieties as well as the case of ramified bundles on smooth curves [4] (see §2, §5 for definitions). Recall that for the case of ...

  9. Quiver Varieties and Branching

    Directory of Open Access Journals (Sweden)

    Hiraku Nakajima

    2009-01-01

    Full Text Available Braverman and Finkelberg recently proposed the geometric Satake correspondence for the affine Kac-Moody group Gaff [Braverman A., Finkelberg M., arXiv:0711.2083]. They conjecture that intersection cohomology sheaves on the Uhlenbeck compactification of the framed moduli space of Gcpt-instantons on $R^4/Z_r$ correspond to weight spaces of representations of the Langlands dual group $G_{aff}^{vee}$ at level $r$. When $G = SL(l$, the Uhlenbeck compactification is the quiver variety of type $sl(r_{aff}$, and their conjecture follows from the author's earlier result and I. Frenkel's level-rank duality. They further introduce a convolution diagram which conjecturally gives the tensor product multiplicity [Braverman A., Finkelberg M., Private communication, 2008]. In this paper, we develop the theory for the branching in quiver varieties and check this conjecture for $G = SL(l$.

  10. Bundles over Quantum RealWeighted Projective Spaces

    Directory of Open Access Journals (Sweden)

    Tomasz Brzeziński

    2012-09-01

    Full Text Available The algebraic approach to bundles in non-commutative geometry and the definition of quantum real weighted projective spaces are reviewed. Principal U(1-bundles over quantum real weighted projective spaces are constructed. As the spaces in question fall into two separate classes, the negative or odd class that generalises quantum real projective planes and the positive or even class that generalises the quantum disc, so do the constructed principal bundles. In the negative case the principal bundle is proven to be non-trivial and associated projective modules are described. In the positive case the principal bundles turn out to be trivial, and so all the associated modules are free. It is also shown that the circle (coactions on the quantum Seifert manifold that define quantum real weighted projective spaces are almost free.

  11. Artificial ciliary bundles with nano fiber tip links

    CERN Document Server

    Asadnia, Mohsen; Miao, Jianmin; Triantafyllou, Michael

    2015-01-01

    Mechanosensory ciliary bundles in fishes are the inspiration for carefully engineered artificial flow sensors. We report the development of a new class of ultrasensitive MEMS flow sensors that mimic the intricate morphology of the ciliary bundles, including the stereocilia, tip links, and the cupula, and thereby achieve threshold detection limits that match the biological example. An artificial ciliary bundle is achieved by fabricating closely-spaced arrays of polymer micro-pillars with gradiating heights. Tip links that form the fundamental sensing elements are realized through electrospinning aligned PVDF piezoelectric nano-fibers that link the distal tips of the polymer cilia. An optimized synthesis of hyaluronic acid-methacrylic anhydride hydrogel that results in properties close to the biological cupula, together with drop-casting method are used to form the artificial cupula that encapsulates the ciliary bundle. In testing, fluid drag force causes the ciliary bundle to slide, stretching the flexible nan...

  12. Superconductivity in an Inhomogeneous Bundle of Metallic and Semiconducting Nanotubes

    Directory of Open Access Journals (Sweden)

    Ilya Grigorenko

    2013-01-01

    Full Text Available Using Bogoliubov-de Gennes formalism for inhomogeneous systems, we have studied superconducting properties of a bundle of packed carbon nanotubes, making a triangular lattice in the bundle's transverse cross-section. The bundle consists of a mixture of metallic and doped semiconducting nanotubes, which have different critical transition temperatures. We investigate how a spatially averaged superconducting order parameter and the critical transition temperature depend on the fraction of the doped semiconducting carbon nanotubes in the bundle. Our simulations suggest that the superconductivity in the bundle will be suppressed when the fraction of the doped semiconducting carbon nanotubes will be less than 0.5, which is the percolation threshold for a two-dimensional triangular lattice.

  13. Framework for shape analysis of white matter fiber bundles.

    Science.gov (United States)

    Glozman, Tanya; Bruckert, Lisa; Pestilli, Franco; Yecies, Derek W; Guibas, Leonidas J; Yeom, Kristen W

    2017-12-02

    Diffusion imaging coupled with tractography algorithms allows researchers to image human white matter fiber bundles in-vivo. These bundles are three-dimensional structures with shapes that change over time during the course of development as well as in pathologic states. While most studies on white matter variability focus on analysis of tissue properties estimated from the diffusion data, e.g. fractional anisotropy, the shape variability of white matter fiber bundle is much less explored. In this paper, we present a set of tools for shape analysis of white matter fiber bundles, namely: (1) a concise geometric model of bundle shapes; (2) a method for bundle registration between subjects; (3) a method for deformation estimation. Our framework is useful for analysis of shape variability in white matter fiber bundles. We demonstrate our framework by applying our methods on two datasets: one consisting of data for 6 normal adults and another consisting of data for 38 normal children of age 11 days to 8.5 years. We suggest a robust and reproducible method to measure changes in the shape of white matter fiber bundles. We demonstrate how this method can be used to create a model to assess age-dependent changes in the shape of specific fiber bundles. We derive such models for an ensemble of white matter fiber bundles on our pediatric dataset and show that our results agree with normative human head and brain growth data. Creating these models for a large pediatric longitudinal dataset may improve understanding of both normal development and pathologic states and propose novel parameters for the examination of the pediatric brain. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Bundling of elastic filaments induced by hydrodynamic interactions

    Science.gov (United States)

    Man, Yi; Page, William; Poole, Robert J.; Lauga, Eric

    2017-12-01

    Peritrichous bacteria swim in viscous fluids by rotating multiple helical flagellar filaments. As the bacterium swims forward, all its flagella rotate in synchrony behind the cell in a tight helical bundle. When the bacterium changes its direction, the flagellar filaments unbundle and randomly reorient the cell for a short period of time before returning to their bundled state and resuming swimming. This rapid bundling and unbundling is, at its heart, a mechanical process whereby hydrodynamic interactions balance with elasticity to determine the time-varying deformation of the filaments. Inspired by this biophysical problem, we present in this paper what is perhaps the simplest model of bundling whereby two or more straight elastic filaments immersed in a viscous fluid rotate about their centerline, inducing rotational flows which tend to bend the filaments around each other. We derive an integrodifferential equation governing the shape of the filaments resulting from mechanical balance in a viscous fluid at low Reynolds number. We show that such equation may be evaluated asymptotically analytically in the long-wavelength limit, leading to a local partial differential equation governed by a single dimensionless bundling number. A numerical study of the dynamics predicted by the model reveals the presence of two configuration instabilities with increasing bundling numbers: first to a crossing state where filaments touch at one point and then to a bundled state where filaments wrap along each other in a helical fashion. We also consider the case of multiple filaments and the unbundling dynamics. We next provide an intuitive physical model for the crossing instability and show that it may be used to predict analytically its threshold and adapted to address the transition to a bundling state. We then use a macroscale experimental implementation of the two-filament configuration in order to validate our theoretical predictions and obtain excellent agreement. This long

  15. Restriction of Preferences to the Set of Consumption Bundles, In a Model with Production and Consumption Bundles

    NARCIS (Netherlands)

    Schalk, S.

    1999-01-01

    In contrast to the neo-classical theory of Arrow and Debreu, a model of a private ownership economy is presented, in which production and consumption bundles are treated separately. Each of the two types of bundles is assumed to establish a con- vex cone. Production technologies can convert

  16. Single-Bundle Versus Double-Bundle Reconstruction for Anterior Cruciate Ligament Rupture: A Meta-Analysis-Does Anatomy Matter?

    NARCIS (Netherlands)

    Eck, Carola F. Van; Kopf, Sebastian; Irrgang, James J.; Blankevoort, Leendert; Bhandari, Mohit; Fu, Freddie H.; Poolman, Rudolf W.

    2012-01-01

    Purpose: To determine whether double-bundle anterior cruciate ligament reconstruction leads to better restoration of anterior and rotational laxity and range of motion than single-bundle reconstruction. Methods: A search was performed in the Medline, Embase, CINAHL, and Cochrane databases. All

  17. Durability of branches in branched and fenestrated endografts.

    Science.gov (United States)

    Mastracci, Tara M; Greenberg, Roy K; Eagleton, Matthew J; Hernandez, Adrian V

    2013-04-01

    Branched and fenestrated repair has been shown to be effective for treatment of complex aortic aneurysms. However, the long-term durability of branches is not well reported. Prospective data collected for all patients enrolled in a physician-sponsored investigational device exemption trial for branched and fenestrated endografts were analyzed. Retrospective review of imaging studies and electronic records was used to supplement the dataset. Incidences of branch stent secondary intervention, stent fracture, migration, branch-related rupture, and death were calculated. A time-to-event analysis was performed for secondary intervention for any branch. Univariable and multivariable analyses were performed to identify related variables. Branch instability, a composite outcome of any branch event, was reported as a function of exponential decay to capture the loss of freedom from complications over time. Between the years 2001 and 2010, 650 patients underwent endovascular aortic repair with branched or fenestrated devices. Over 9 years of follow-up (mean [standard deviation], 3 [2.3] years), secondary procedures were performed for 0.6% of celiac, 4% of superior mesenteric artery (SMA), 6% of right renal artery, and 5% of left renal artery stents. Mean time to reintervention was 237 (354) days. The 30-day, 1-year, and 5-year freedom from branch intervention was 98% (95% confidence interval [CI], 96%-99%), 94% (95% CI, 92%-96%), and 84% (95% CI, 78%-90%), respectively. Death from branch stent complications occurred in three patients, two related to SMA thrombosis and one due to an unstented SMA scallop. Multivariable analysis revealed no factors as independent predictors of need for branch reintervention. Branches, after branched or fenestrated aortic repair, appear to be durable and are rarely the cause of patient death. The absence of long-term data on branch patency in open repair precludes comparison, yet the lower morbidity and mortality risk coupled with longer

  18. Study on heat and mass transfer characteristics of humid air-flow in a fin bundle

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong-Hwi [Air-Conditioner Research Laboratory, LG Electronics, Seoul 153-082 (Korea); Koyama, Shigeru; Kuwahara, Ken [Department of Energy and Environmental Engineering, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Kwon, Jeong-Tae [Department of Mechanical Engineering, Hoseo University, Asan, Chungnam 336-795 (Korea); Park, Byung-Duck [School of Mechanical and Automotive Engineering, Kyungpook National University, Sangju, Gyeongbuk 742-711 (Korea)

    2010-11-15

    This paper deals with the heat and mass transfer characteristics of humid air-flow under frosting conditions. A slit fin bundle was used for the simulation of fins of a heat exchanger. The effects of the cooling block temperature, air humidity and air velocity on the frosting characteristics were experimentally investigated. The frosted mass was affected considerably by the cooling block temperature and air humidity. However, the effect of air velocity on it was not so large. The pressure drop was affected remarkably by all experimental parameters in this study. Local heat flux distribution and frost thickness distribution on each fin were predicted from the measured fin temperatures and the mass and energy conservation equations on the frost surface and inside the frost layer. (author)

  19. The control of branching morphogenesis

    Science.gov (United States)

    Iber, Dagmar; Menshykau, Denis

    2013-01-01

    Many organs of higher organisms are heavily branched structures and arise by an apparently similar process of branching morphogenesis. Yet the regulatory components and local interactions that have been identified differ greatly in these organs. It is an open question whether the regulatory processes work according to a common principle and how far physical and geometrical constraints determine the branching process. Here, we review the known regulatory factors and physical constraints in lung, kidney, pancreas, prostate, mammary gland and salivary gland branching morphogenesis, and describe the models that have been formulated to analyse their impacts. PMID:24004663

  20. Methods and Technologies Branch (MTB)

    Science.gov (United States)

    The Methods and Technologies Branch focuses on methods to address epidemiologic data collection, study design and analysis, and to modify technological approaches to better understand cancer susceptibility.

  1. Cost-effectiveness of a central venous catheter care bundle.

    Directory of Open Access Journals (Sweden)

    Kate A Halton

    Full Text Available BACKGROUND: A bundled approach to central venous catheter care is currently being promoted as an effective way of preventing catheter-related bloodstream infection (CR-BSI. Consumables used in the bundled approach are relatively inexpensive which may lead to the conclusion that the bundle is cost-effective. However, this fails to consider the nontrivial costs of the monitoring and education activities required to implement the bundle, or that alternative strategies are available to prevent CR-BSI. We evaluated the cost-effectiveness of a bundle to prevent CR-BSI in Australian intensive care patients. METHODS AND FINDINGS: A Markov decision model was used to evaluate the cost-effectiveness of the bundle relative to remaining with current practice (a non-bundled approach to catheter care and uncoated catheters, or use of antimicrobial catheters. We assumed the bundle reduced relative risk of CR-BSI to 0.34. Given uncertainty about the cost of the bundle, threshold analyses were used to determine the maximum cost at which the bundle remained cost-effective relative to the other approaches to infection control. Sensitivity analyses explored how this threshold alters under different assumptions about the economic value placed on bed-days and health benefits gained by preventing infection. If clinicians are prepared to use antimicrobial catheters, the bundle is cost-effective if national 18-month implementation costs are below $1.1 million. If antimicrobial catheters are not an option the bundle must cost less than $4.3 million. If decision makers are only interested in obtaining cash-savings for the unit, and place no economic value on either the bed-days or the health benefits gained through preventing infection, these cost thresholds are reduced by two-thirds. CONCLUSIONS: A catheter care bundle has the potential to be cost-effective in the Australian intensive care setting. Rather than anticipating cash-savings from this intervention, decision

  2. Bundling Actin Filaments From Membranes: Some Novel Players

    Directory of Open Access Journals (Sweden)

    Clément eThomas

    2012-08-01

    Full Text Available Progress in live-cell imaging of the cytoskeleton has significantly extended our knowledge about the organization and dynamics of actin filaments near the plasma membrane of plant cells. Noticeably, two populations of filamentous structures can be distinguished. On the one hand, fine actin filaments which exhibit an extremely dynamic behavior basically characterized by fast polymerization and prolific severing events, a process referred to as actin stochastic dynamics. On the other hand, thick actin bundles which are composed of several filaments and which are comparatively more stable although they constantly remodel as well. There is evidence that the actin cytoskeleton plays critical roles in trafficking and signaling at both the cell cortex and organelle periphery but the exact contribution of actin bundles remains unclear. A common view is that actin bundles provide the long-distance tracks used by myosin motors to deliver their cargo to growing regions and accordingly play a particularly important role in cell polarization. However, several studies support that actin bundles are more than simple passive highways and display multiple and dynamic roles in the regulation of many processes, such as cell elongation, polar auxin transport, stomatal and chloroplast movement, and defense against pathogens. The list of identified plant actin-bundling proteins is ever expanding, supporting that plant cells shape structurally and functionally different actin bundles. Here I review the most recently characterized actin-bundling proteins, with a particular focus on those potentially relevant to membrane trafficking and/or signaling.

  3. Tau hadronic branching ratios

    CERN Document Server

    Buskulic, Damir; De Bonis, I; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Odier, P; Pietrzyk, B; Ariztizabal, F; Chmeissani, M; Crespo, J M; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Gaitan, V; Martínez, M; Orteu, S; Pacheco, A; Padilla, C; Palla, Fabrizio; Pascual, A; Perlas, J A; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Farilla, A; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Natali, S; Nuzzo, S; Ranieri, A; Raso, G; Romano, F; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Bonvicini, G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Engelhardt, A; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Jacobsen, R; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Markou, C; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Oest, T; Palazzi, P; Pater, J R; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wiedenmann, W; Wildish, T; Witzeling, W; Wotschack, J; Ajaltouni, Ziad J; Bardadin-Otwinowska, Maria; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rossignol, J M; Saadi, F; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Kyriakis, A; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Passalacqua, L; Rougé, A; Rumpf, M; Tanaka, R; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Delfino, M C; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Pepé-Altarelli, M; Dorris, S J; Halley, A W; ten Have, I; Knowles, I G; Lynch, J G; Morton, W T; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Smith, M G; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Braun, O; Geweniger, C; Graefe, G; Hanke, P; Hepp, V; Kluge, E E; Putzer, A; Rensch, B; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Colling, D J; Dornan, Peter J; Konstantinidis, N P; Moneta, L; Moutoussi, A; Nash, J; San Martin, G; Sedgbeer, J K; Stacey, A M; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Bowdery, C K; Brodbeck, T J; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Whelan, E P; Williams, M I; Galla, A; Greene, A M; Kleinknecht, K; Quast, G; Raab, J; Renk, B; Sander, H G; Wanke, R; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Thulasidas, M; Nicod, D; Payre, P; Rousseau, D; Talby, M; Abt, I; Assmann, R W; Bauer, C; Blum, Walter; Brown, D; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Jakobs, K; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Wolf, G; Alemany, R; Boucrot, J; Callot, O; Cordier, A; Courault, F; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Musolino, G; Nikolic, I A; Park, H J; Park, I C; Schune, M H; Simion, S; Veillet, J J; Videau, I; Abbaneo, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Rizzo, G; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Triggiani, G; Vannini, C; Verdini, P G; Walsh, J; Betteridge, A P; Blair, G A; Bryant, L M; Cerutti, F; Gao, Y; Green, M G; Johnson, D L; Medcalf, T; Mir, L M; Perrodo, P; Strong, J A; Bertin, V; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Edwards, M; Maley, P; Norton, P R; Thompson, J C; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Beddall, A; Booth, C N; Boswell, R; Cartwright, S L; Combley, F; Dawson, I; Köksal, A; Letho, M; Newton, W M; Rankin, C; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Feigl, E; Grupen, Claus; Lutters, G; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Ragusa, F; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Bellantoni, L; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Harton, J L; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Schmitt, M; Scott, I J; Sharma, V; Turk, J; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G

    1996-01-01

    From 64492 selected \\tau-pair events, produced at the Z^0 resonance, the measurement of the tau decays into hadrons from a global analysis using 1991, 1992 and 1993 ALEPH data is presented. Special emphasis is given to the reconstruction of photons and \\pi^0's, and the removal of fake photons. A detailed study of the systematics entering the \\pi^0 reconstruction is also given. A complete and consistent set of tau hadronic branching ratios is presented for 18 exclusive modes. Most measurements are more precise than the present world average. The new level of precision reached allows a stringent test of \\tau-\\mu universality in hadronic decays, g_\\tau/g_\\mu \\ = \\ 1.0013 \\ \\pm \\ 0.0095, and the first measurement of the vector and axial-vector contributions to the non-strange hadronic \\tau decay width: R_{\\tau ,V} \\ = \\ 1.788 \\ \\pm \\ 0.025 and R_{\\tau ,A} \\ = \\ 1.694 \\ \\pm \\ 0.027. The ratio (R_{\\tau ,V} - R_{\\tau ,A}) / (R_{\\tau ,V} + R_{\\tau ,A}), equal to (2.7 \\pm 1.3) \\ \\%, is a measure of the importance of Q...

  4. Aerosol retention in the flooded steam generator bundle during SGTR

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Terttaliisa, E-mail: terttaliisa.lind@psi.c [Paul Scherrer Institut, Department of Nuclear Energy and Safety, 5232 Villigen (Switzerland); Dehbi, Abdel; Guentay, Salih [Paul Scherrer Institut, Department of Nuclear Energy and Safety, 5232 Villigen (Switzerland)

    2011-01-15

    Research highlights: High retention of aerosol particles in a steam generator bundle flooded with water. Increasing particle inertia, i.e., particle size and velocity, increases retention. Much higher retention of aerosol particles in the steam generator bundle flooded with water than in a dry bundle. Much higher retention of aerosol particles in the steam generator bundle than in a bare pool. Bare pool models have to be adapted to be applicable for flooded bundles. - Abstract: A steam generator tube rupture in a pressurized water reactor may cause accidental release of radioactive particles into the environment. Its specific significance is in its potential to bypass the containment thereby providing a direct pathway of the radioactivity from the primary circuit to the environment. Under certain severe accident scenarios, the steam generator bundle may be flooded with water. In addition, some severe accident management procedures are designed to minimize the release of radioactivity into the environment by flooding the defective steam generator secondary side with water when the steam generator has dried out. To extend our understanding of the particle retention phenomena in the flooded steam generator bundle, tests were conducted in the ARTIST and ARTIST II programs to determine the effect of different parameters on particle retention. The effects of particle type (spherical or agglomerate), particle size, gas mass flow rate, and the break submergence on particle retention were investigated. Results can be summarized as follows: increasing particle inertia was found to increase retention in the flooded bundle. Particle shape, i.e., agglomerate or spherical structure, did not affect retention significantly. Even with a very low submergence, 0.3 m above the tube break, significant aerosol retention took place underlining the importance of the jet-bundle interactions close to the tube break. Droplets were entrained from the water surface with high gas flow rates

  5. Legislative Branch: FY2014 Appropriations

    Science.gov (United States)

    2013-11-25

    Authorizations Since 1999, by Matthew E. Glassman . Legislative Branch: FY2014 Appropriations Congressional Research Service 10 The FY2012 level of...Congresses, by Matthew E. Glassman . Legislative Branch: FY2014 Appropriations Congressional Research Service 11 Members’ Representational...vehicles; communications equipment; security equipment and its installation; dignitary protection; intelligence analysis; hazardous material response

  6. Dark-field illuminated reflectance fiber bundle endoscopic microscope

    Science.gov (United States)

    Liu, Xuan; Huang, Yong; Kang, Jin U.

    2011-04-01

    We propose a reflectance fiber bundle microscope using a dark-field illumination configuration for applications in endoscopic medical imaging and diagnostics. Our experiment results show that dark-field illumination can effectively suppress strong specular reflection from the proximal end of the fiber bundle. We realized a lateral resolution of 4.4 μm using the dark-field illuminated fiber bundle configuration. To demonstrate the feasibility of using the system to study cell morphology, we obtained still and video images of two thyroid cancer cell lines. Our results clearly allow differentiation of different cancer cell types.

  7. Moduli of Parabolic Higgs Bundles and Atiyah Algebroids

    DEFF Research Database (Denmark)

    Logares, Marina; Martens, Johan

    2010-01-01

    In this paper we study the geometry of the moduli space of (non-strongly) parabolic Higgs bundles over a Riemann surface with marked points. We show that this space possesses a Poisson structure, extending the one on the dual of an Atiyah algebroid over the moduli space of parabolic vector bundles....... By considering the case of full flags, we get a Grothendieck–Springer resolution for all other flag types, in particular for the moduli spaces of twisted Higgs bundles, as studied by Markman and Bottacin and used in the recent work of Laumon–Ngô. We discuss the Hitchin system, and demonstrate that all...

  8. Simulation of finite size effects of the fiber bundle model

    Science.gov (United States)

    Hao, Da-Peng; Tang, Gang; Xun, Zhi-Peng; Xia, Hui; Han, Kui

    2018-01-01

    In theory, the macroscopic fracture of materials should correspond with the thermodynamic limit of the fiber bundle model. However, the simulation of a fiber bundle model with an infinite size is unrealistic. To study the finite size effects of the fiber bundle model, fiber bundle models of various size are simulated in detail. The effects of system size on the constitutive behavior, critical stress, maximum avalanche size, avalanche size distribution, and increased step number of external load are explored. The simulation results imply that there is no feature size or cut size for macroscopic mechanical and statistical properties of the model. The constitutive curves near the macroscopic failure for various system size can collapse well with a simple scaling relationship. Simultaneously, the introduction of a simple extrapolation method facilitates the acquisition of more accurate simulation results in a large-limit system, which is better for comparison with theoretical results.

  9. Improved Conjugate Gradient Bundle Adjustment of Dunhuang Wall Painting Images

    Science.gov (United States)

    Hu, K.; Huang, X.; You, H.

    2017-09-01

    Bundle adjustment with additional parameters is identified as a critical step for precise orthoimage generation and 3D reconstruction of Dunhuang wall paintings. Due to the introduction of self-calibration parameters and quasi-planar constraints, the structure of coefficient matrix of the reduced normal equation is banded-bordered, making the solving process of bundle adjustment complex. In this paper, Conjugate Gradient Bundle Adjustment (CGBA) method is deduced by calculus of variations. A preconditioning method based on improved incomplete Cholesky factorization is adopt to reduce the condition number of coefficient matrix, as well as to accelerate the iteration rate of CGBA. Both theoretical analysis and experimental results comparison with conventional method indicate that, the proposed method can effectively conquer the ill-conditioned problem of normal equation and improve the calculation efficiency of bundle adjustment with additional parameters considerably, while maintaining the actual accuracy.

  10. Bundles of Norms About Teen Sex and Pregnancy.

    Science.gov (United States)

    Mollborn, Stefanie; Sennott, Christie

    2015-09-01

    Teen pregnancy is a cultural battleground in struggles over morality, education, and family. At its heart are norms about teen sex, contraception, pregnancy, and abortion. Analyzing 57 interviews with college students, we found that "bundles" of related norms shaped the messages teens hear. Teens did not think their communities encouraged teen sex or pregnancy, but normative messages differed greatly, with either moral or practical rationalizations. Teens readily identified multiple norms intended to regulate teen sex, contraception, abortion, childbearing, and the sanctioning of teen parents. Beyond influencing teens' behavior, norms shaped teenagers' public portrayals and post hoc justifications of their behavior. Although norm bundles are complex to measure, participants could summarize them succinctly. These bundles and their conflicting behavioral prescriptions create space for human agency in negotiating normative pressures. The norm bundles concept has implications for teen pregnancy prevention policies and can help revitalize social norms for understanding health behaviors. © The Author(s) 2014.

  11. Some applications on tangent bundle with Kaluza-Klein metric

    Directory of Open Access Journals (Sweden)

    Murat Altunbaş

    2017-01-01

    Full Text Available In this paper, differential equations of geodesics; parallelism, incompressibility and closeness conditions of the horizontal and complete lift of the vector fields are investigated with respect to Kaluza-Klein metric on tangent bundle.

  12. Algebraic Frobenius splitting of cotangent bundles of flag varieties

    National Research Council Canada - National Science Library

    Hague, Chuck

    2013-01-01

    Following the program of algebraic Frobenius splitting begun by Kumar and Littelmann, we use representation-theoretic techniques to construct a Frobenius splitting of the cotangent bundle of the flag...

  13. Design and synthesis of DNA four-helix bundles.

    Science.gov (United States)

    Rangnekar, Abhijit; Gothelf, Kurt V; LaBean, Thomas H

    2011-06-10

    The field of DNA nanotechnology has evolved significantly in the past decade. Researchers have succeeded in synthesizing tile-based structures and using them to form periodic lattices in one, two and three dimensions. Origami-based structures have also been used to create nanoscale structures in two and three dimensions. Design and construction of DNA bundles with fixed circumference has added a new dimension to the field. Here we report the design and synthesis of a DNA four-helix bundle. It was found to be extremely rigid and stable. When several such bundles were assembled using appropriate sticky-ends, they formed micrometre-long filaments. However, when creation of two-dimensional sheet-like arrays of the four-helix bundles was attempted, nanoscale rings were observed instead. The exact reason behind the nanoring formation is yet to be ascertained, but it provides an exciting prospect for making programmable circular nanostructures using DNA.

  14. IMPROVED CONJUGATE GRADIENT BUNDLE ADJUSTMENT OF DUNHUANG WALL PAINTING IMAGES

    Directory of Open Access Journals (Sweden)

    K. Hu

    2017-09-01

    Full Text Available Bundle adjustment with additional parameters is identified as a critical step for precise orthoimage generation and 3D reconstruction of Dunhuang wall paintings. Due to the introduction of self-calibration parameters and quasi-planar constraints, the structure of coefficient matrix of the reduced normal equation is banded-bordered, making the solving process of bundle adjustment complex. In this paper, Conjugate Gradient Bundle Adjustment (CGBA method is deduced by calculus of variations. A preconditioning method based on improved incomplete Cholesky factorization is adopt to reduce the condition number of coefficient matrix, as well as to accelerate the iteration rate of CGBA. Both theoretical analysis and experimental results comparison with conventional method indicate that, the proposed method can effectively conquer the ill-conditioned problem of normal equation and improve the calculation efficiency of bundle adjustment with additional parameters considerably, while maintaining the actual accuracy.

  15. CANFLEX fuel bundle cross-flow endurance test (test report)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Deok; Chung, C. H.; Chang, S. K.; Kim, B. D.

    1997-04-01

    As part of the normal refuelling sequence of CANDU nuclear reactor, both new and irradiated bundles can be parked in the cross-flow region of the liner tubes. This situation occurs normally for a few minutes. The fuel bundle which is subjected to the cross-flow should be capable of withstanding the consequences of cross flow for normal periods, and maintain its mechanical integrity. The cross-flow endurance test was conducted for CANFLEX bundle, latest developed nuclear fuel, at CANDU-Hot Test Loop. The test was carried out during 4 hours at the inlet cross-flow region. After the test, the bundle successfully met all acceptance criteria after the 4 hours cross-flow test. (author). 2 refs., 3 tabs.

  16. Introductory lectures on fibre bundles and topology for physicists

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, G.H.

    1978-05-01

    These lectures may provide useful background material for understanding gauge theories, particularly the nonperturbative effects such as instantons and monopoles. The mathematical language of topology and fibre bundles is introduced.

  17. Bohr--Sommerfeld Lagrangians of moduli spaces of Higgs bundles

    DEFF Research Database (Denmark)

    Biswas, Indranil; Gammelgaard, Niels Leth; Logares, Marina

    Let $X$ be a compact connected Riemann surface of genus at least two. Let $M_H(r,d)$ denote the moduli space of semistable Higgs bundles on $X$ of rank $r$ and degree $d$. We prove that the compact complex Bohr-Sommerfeld Lagrangians of $M_H(r,d)$ are precisely the irreducible components of the n......Let $X$ be a compact connected Riemann surface of genus at least two. Let $M_H(r,d)$ denote the moduli space of semistable Higgs bundles on $X$ of rank $r$ and degree $d$. We prove that the compact complex Bohr-Sommerfeld Lagrangians of $M_H(r,d)$ are precisely the irreducible components...... of the nilpotent cone in $M_H(r,d)$. This generalizes to Higgs $G$-bundles and also to the parabolic Higgs bundles....

  18. Design and synthesis of DNA four-helix bundles

    Energy Technology Data Exchange (ETDEWEB)

    Rangnekar, Abhijit; Gothelf, Kurt V [Department of Chemistry, Centre for DNA Nanotechnology (CDNA) and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000 Aarhus C (Denmark); LaBean, Thomas H, E-mail: kvg@chem.au.dk, E-mail: thl@cs.duke.edu [Department of Chemistry, Duke University, Durham, NC 27708 (United States)

    2011-06-10

    The field of DNA nanotechnology has evolved significantly in the past decade. Researchers have succeeded in synthesizing tile-based structures and using them to form periodic lattices in one, two and three dimensions. Origami-based structures have also been used to create nanoscale structures in two and three dimensions. Design and construction of DNA bundles with fixed circumference has added a new dimension to the field. Here we report the design and synthesis of a DNA four-helix bundle. It was found to be extremely rigid and stable. When several such bundles were assembled using appropriate sticky-ends, they formed micrometre-long filaments. However, when creation of two-dimensional sheet-like arrays of the four-helix bundles was attempted, nanoscale rings were observed instead. The exact reason behind the nanoring formation is yet to be ascertained, but it provides an exciting prospect for making programmable circular nanostructures using DNA.

  19. A Discrete Theory of Connections on Principal Bundles

    OpenAIRE

    Leok, M; Marsden, JE; Weinstein, AD

    2017-01-01

    Connections on principal bundles play a fundamental role in expressing the equations of motion for mechanical systems with symmetry in an intrinsic fashion. A discrete theory of connections on principal bundles is constructed by introducing the discrete analogue of the Atiyah sequence, with a connection corresponding to the choice of a splitting of the short exact sequence. Equivalent representations of a discrete connection are considered, and an extension of the pair groupoid composition, t...

  20. On the Geometry of Cotangent Bundles of Lie Groups

    OpenAIRE

    Manga, Bakary

    2015-01-01

    Lie groups of automorphisms of cotangent bundles of Lie groups are completely characterized and interesting results are obtained. We give prominence to the fact that the Lie groups of automorphisms of cotangent bundles of Lie groups are super symmetric Lie groups. In the cases of orthogonal Lie lgebras, semi-simple Lie algebras and compact Lie algebras we recover by simple methods interesting co-homological known results. The Lie algebra of prederivations encompasses the one of derivations as...

  1. CHF prediction in rod bundles using round tube data

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Wallen F.; Veloso, Maria A.F.; Pereira, Cláubia; Costa, Antonella L., E-mail: wallenfds@yahoo.com.br, E-mail: mdora@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2017-07-01

    The present work concerns the use of 1995 CHF table for uniformly heated round tubes, developed jointly by Canadian and Russian researchers, for the prediction of critical heat fluxes in rod bundles geometries. Comparisons between measured and calculated critical heat fluxes indicate that this table could be applied to rod bundles provided that a suitable correction factor is employed. The tolerance limits associated with the departure from nucleate boiling ratio (DNBR) are evaluated by using statistical analysis. (author)

  2. Page 1 Moduli for bundles over curves - 325 through the ...

    Indian Academy of Sciences (India)

    (B End V, with the reduced structure. Note that C is an open subscheme in C and C is a multicone in G) End V. By the hypothesis of the lemma and assumption Mo = G, for te Twe have an isomorphism (p, Eo- ºr, We can interpret p, as a section of the fiber bundle (e. X ..) (G) with fiber G associated to the G × G. bundle Eo * Č, ...

  3. Mitotic spindle: kinetochore fibers hold on tight to interpolar bundles.

    Science.gov (United States)

    Tolić, Iva M

    2017-07-19

    When a cell starts to divide, it forms a spindle, a micro-machine made of microtubules, which separates the duplicated chromosomes. The attachment of microtubules to chromosomes is mediated by kinetochores, protein complexes on the chromosome. Spindle microtubules can be divided into three major classes: kinetochore microtubules, which form k-fibers ending at the kinetochore; interpolar microtubules, which extend from the opposite sides of the spindle and interact in the middle; and astral microtubules, which extend towards the cell cortex. Recent work in human cells has shown a close relationship between interpolar and kinetochore microtubules, where interpolar bundles are attached laterally to kinetochore fibers almost all along their length, acting as a bridge between sister k-fibers. Most of the interpolar bundles are attached to a pair of sister kinetochore fibers and vice versa. Thus, the spindle is made of modules consisting of a pair of sister kinetochore fibers and a bundle of interpolar microtubules that connects them. These interpolar bundles, termed bridging fibers, balance the forces acting at kinetochores and support the rounded shape of the spindle during metaphase. This review discusses the structure, function, and formation of kinetochore fibers and interpolar bundles, with an emphasis on how they interact. Their connections have an impact on the force balance in the spindle and on chromosome movement during mitosis because the forces in interpolar bundles are transmitted to kinetochore fibers and hence to kinetochores through these connections.

  4. Splitting 3-plane sub-bundles over the product of two real projective spaces

    Directory of Open Access Journals (Sweden)

    Maria Hermínia de Paula Leite Mello

    2003-11-01

    Full Text Available Let α be a real vector bundle of fiber dimension three over the product RP(m×RP(n which splits as a Whitney sum of line bundles. We show that the necessary and sufficient conditions for α to embed as a sub-bundle of a certain family of vector bundles β of fiber dimension m+n is the vanishing of the last three Stiefel-Whitney classes of the virtual bundle0 β−α. Among the target bundles β we consider the tangent bundle.

  5. Models of lung branching morphogenesis.

    Science.gov (United States)

    Miura, Takashi

    2015-03-01

    Vertebrate airway has a tree-like-branched structure. This structure is generated by repeated tip splitting, which is called branching morphogenesis. Although this phenomenon is extensively studied in developmental biology, the mechanism of the pattern formation is not well understood. Conversely, there are many tree-like structures in purely physical or chemical systems, and their pattern formation mechanisms are well-understood using mathematical models. Recent studies correlate these biological observations and mathematical models to understand lung branching morphogenesis. These models use slightly different mechanisms. In this article, we will review recent progress in modelling lung branching morphogenesis, and future directions to experimentally verify the models. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  6. SCADOP: Phenomenological modeling of dryout in nuclear fuel rod bundles

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, Arnab, E-mail: arnie@barc.gov.in; Chandraker, D.K., E-mail: dineshkc@barc.gov.in; Vijayan, P.K., E-mail: vijayanp@barc.gov.in

    2015-11-15

    Highlights: • Phenomenological model for annular flow dryout is presented. • The model evaluates initial entrained fraction using a new methodology. • The history effect in annular flow is predicted and validated. • Rod bundle dryout is predicted using subchannel methodology. • Model is validated against experimental dryout data in tubes and rod bundles. - Abstract: Analysis and prediction of dryout is of important consequence to safety of nuclear fuel clusters of boiling water type of reactors. Traditionally, experimental correlations are used for dryout predictions. Since these correlations are based on operating parameters and do not aim to model the underlying phenomena, there has been a proliferation of the correlations, each catering to some specific bundle geometry under a specific set of operating conditions. Moreover, such experiments are extremely costly. In general, changes in tested bundle geometry for improvement in thermal-hydraulic performance would require re-experimentation. Understanding and modeling the basic processes leading to dryout in flow boiling thus has great incentive. Such a model has the ability to predict dryout in any rod bundle geometry, unlike the operating parameter based correlation approach. Thus more informed experiments can be carried out. A good model can, reduce the number of experiments required during the iterations in bundle design. In this paper, a phenomenological model as indicated above is presented. The model incorporates a new methodology to estimate the Initial Entrained Fraction (IEF), i.e., entrained fraction at the onset of annular flow. The incorporation of this new methodology is important since IEF is often assumed ad-hoc and sometimes also used as a parameter to tune the model predictions to experimental data. It is highlighted that IEF may be low under certain conditions against the general perception of a high IEF due to influence of churn flow. It is shown that the same phenomenological model is

  7. Long chain branching of PLA

    Science.gov (United States)

    Gu, Liangliang; Xu, Yuewen; Fahnhorst, Grant; Macosko, Christopher W.

    2017-05-01

    A trifunctional aziridine linker, trimethylolpropane tris(2-methyl-1-aziridinepropionate) (TTMAP), was melt blended with linear polylactic acid (PLA) to make star branched PLA. Adding pyromellitic dianhydride (PMDA) led to long chain branched (LCB) PLA. Mixing torque evolution during melt processing revealed high reactivity of aziridine with the carboxyl end group on PLA and an incomplete reaction of PMDA with the hydroxyl end group. Star-shaped PLA exhibited higher viscosity but no strain hardening in extensional flow while LCB PLA showed significant extensional hardening. Excess TTMAP in the branching reaction resulted in gel formation, which led to failure at low strain in extension. PMDA conversion was estimated based on gelation theory. The strain rate dependence of extensional hardening indicated that the LCB PLA had a low concentration of long chain branched molecules with an H-shaped topology. Unlike current methods used to branch PLA, free radical chemistry or use of an epoxy functional oligomers, our branching strategy produced strain hardening with less increase in shear viscosity. This study provides guidelines for design of polymers with low shear viscosity, which reduces pressure drop in extrusion, combined with strong extensional hardening, which enhances performance in processes that involve melt stretching.

  8. Structural Mechanics and Dynamics Branch

    Science.gov (United States)

    Stefko, George

    2003-01-01

    The 2002 annual report of the Structural Mechanics and Dynamics Branch reflects the majority of the work performed by the branch staff during the 2002 calendar year. Its purpose is to give a brief review of the branch s technical accomplishments. The Structural Mechanics and Dynamics Branch develops innovative computational tools, benchmark experimental data, and solutions to long-term barrier problems in the areas of propulsion aeroelasticity, active and passive damping, engine vibration control, rotor dynamics, magnetic suspension, structural mechanics, probabilistics, smart structures, engine system dynamics, and engine containment. Furthermore, the branch is developing a compact, nonpolluting, bearingless electric machine with electric power supplied by fuel cells for future "more electric" aircraft. An ultra-high-power-density machine that can generate projected power densities of 50 hp/lb or more, in comparison to conventional electric machines, which generate usually 0.2 hp/lb, is under development for application to electric drives for propulsive fans or propellers. In the future, propulsion and power systems will need to be lighter, to operate at higher temperatures, and to be more reliable in order to achieve higher performance and economic viability. The Structural Mechanics and Dynamics Branch is working to achieve these complex, challenging goals.

  9. Structures of building blocks in clusters of sweetpotato amylopectin.

    Science.gov (United States)

    Zhu, Fan; Corke, Harold; Åman, Per; Bertoft, Eric

    2011-12-27

    φ,β-Limit dextrins of domains and clusters of sweetpotato amylopectin were subjected to extensive hydrolysis by Bacillus amyloliquefaciens α-amylase to release building blocks and reveal the internal structures of clusters. The composition of building blocks was analyzed by size-fractionation, gel permeation chromatography, and high performance anion exchange chromatography. Different domains and clusters had structurally similar building blocks with around three chains per building block and internal chain length around 2.9. Singly branched and doubly branched building blocks were the largest and second largest groups in the clusters. Type A clusters had more large building blocks and contained 5-6 blocks per cluster with an inter-block chain length (IB-CL) of 7.0, whereas type B clusters had less large building blocks and contained 3-4 blocks per cluster with IB-CL 7.9. Models on how the building blocks could be organized into type A and type B clusters are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. The Geometry of the Fano Surface of the Double Cover of P^3 Branched in a Quartic

    Science.gov (United States)

    Tihomirov, A. S.

    1981-04-01

    This paper gives a computation of the irregularity of the Fano surface \\mathcal{F} of lines on the double cover X\\to P^3 branched in a quartic. A tangent bundle theorem is proved for \\mathcal{F}, from which it follows that \\mathcal{F} determines X uniquely. It is shown that the Abel-Jacobi map a\\colon \\operatorname{Alb}(\\mathcal{F})\\to J_3(X) is an isogeny. Bibliography: 8 titles.

  11. Histones bundle F-actin filaments and affect actin structure.

    Science.gov (United States)

    Blotnick, Edna; Sol, Asaf; Muhlrad, Andras

    2017-01-01

    Histones are small polycationic proteins complexed with DNA located in the cell nucleus. Upon apoptosis they are secreted from the cells and react with extracellular polyanionic compounds. Actin which is a polyanionic protein, is also secreted from necrotic cells and interacts with histones. We showed that both histone mixture (histone type III) and the recombinant H2A histone bundles F-actin, increases the viscosity of the F-actin containing solution and polymerizes G-actin. The histone-actin bundles are relatively insensitive to increase of ionic strength, unlike other polycation, histatin, lysozyme, spermine and LL-37 induced F-actin bundles. The histone-actin bundles dissociate completely only in the presence of 300-400 mM NaCl. DNA, which competes with F-actin for histones, disassembles histone induced actin bundles. DNase1, which depolymerizes F- to G-actin, actively unbundles the H2A histone induced but slightly affects the histone mixture induced actin bundles. Cofilin decreases the amount of F-actin sedimented by low speed centrifugation, increases light scattering and viscosity of F-actin-histone mixture containing solutions and forms star like superstructures by copolymerizing G-actin with H2A histone. The results indicate that histones are tightly attached to F-actin by strong electrostatic and hydrophobic forces. Since both histones and F-actin are present in the sputum of patients with cystic fibrosis, therefore, the formation of the stable histone-actin bundles can contribute to the pathology of this disease by increasing the viscosity of the sputum. The actin-histone interaction in the nucleus might affect gene expression.

  12. Histones bundle F-actin filaments and affect actin structure.

    Directory of Open Access Journals (Sweden)

    Edna Blotnick

    Full Text Available Histones are small polycationic proteins complexed with DNA located in the cell nucleus. Upon apoptosis they are secreted from the cells and react with extracellular polyanionic compounds. Actin which is a polyanionic protein, is also secreted from necrotic cells and interacts with histones. We showed that both histone mixture (histone type III and the recombinant H2A histone bundles F-actin, increases the viscosity of the F-actin containing solution and polymerizes G-actin. The histone-actin bundles are relatively insensitive to increase of ionic strength, unlike other polycation, histatin, lysozyme, spermine and LL-37 induced F-actin bundles. The histone-actin bundles dissociate completely only in the presence of 300-400 mM NaCl. DNA, which competes with F-actin for histones, disassembles histone induced actin bundles. DNase1, which depolymerizes F- to G-actin, actively unbundles the H2A histone induced but slightly affects the histone mixture induced actin bundles. Cofilin decreases the amount of F-actin sedimented by low speed centrifugation, increases light scattering and viscosity of F-actin-histone mixture containing solutions and forms star like superstructures by copolymerizing G-actin with H2A histone. The results indicate that histones are tightly attached to F-actin by strong electrostatic and hydrophobic forces. Since both histones and F-actin are present in the sputum of patients with cystic fibrosis, therefore, the formation of the stable histone-actin bundles can contribute to the pathology of this disease by increasing the viscosity of the sputum. The actin-histone interaction in the nucleus might affect gene expression.

  13. Ultrasound guided supraclavicular block.

    LENUS (Irish Health Repository)

    Hanumanthaiah, Deepak

    2013-09-01

    Ultrasound guided regional anaesthesia is becoming increasingly popular. The supraclavicular block has been transformed by ultrasound guidance into a potentially safe superficial block. We reviewed the techniques of performing supraclavicular block with special focus on ultrasound guidance.

  14. Apical constriction initiates new bud formation during monopodial branching of the embryonic chicken lung.

    Science.gov (United States)

    Kim, Hye Young; Varner, Victor D; Nelson, Celeste M

    2013-08-01

    Branching morphogenesis sculpts the airway epithelium of the lung into a tree-like structure to conduct air and promote gas exchange after birth. In the avian lung, a series of buds emerges from the dorsal surface of the primary bronchus via monopodial branching to form the conducting airways; anatomically, these buds are similar to those formed by domain branching in the mammalian lung. Here, we show that monopodial branching is initiated by apical constriction of the airway epithelium, and not by differential cell proliferation, using computational modeling and quantitative imaging of embryonic chicken lung explants. Both filamentous actin and phosphorylated myosin light chain were enriched at the apical surface of the airway epithelium during monopodial branching. Consistently, inhibiting actomyosin contractility prevented apical constriction and blocked branch initiation. Although cell proliferation was enhanced along the dorsal and ventral aspects of the primary bronchus, especially before branch formation, inhibiting proliferation had no effect on the initiation of branches. To test whether the physical forces from apical constriction alone are sufficient to drive the formation of new buds, we constructed a nonlinear, three-dimensional finite element model of the airway epithelium and used it to simulate apical constriction and proliferation in the primary bronchus. Our results suggest that, consistent with the experimental results, apical constriction is sufficient to drive the early stages of monopodial branching whereas cell proliferation is dispensable. We propose that initial folding of the airway epithelium is driven primarily by apical constriction during monopodial branching of the avian lung.

  15. An in vitro biomechanical comparison of anterior cruciate ligament reconstruction: single bundle versus anatomical double bundle techniques

    Directory of Open Access Journals (Sweden)

    Sandra Umeda Sasaki

    2008-01-01

    Full Text Available INTRODUCTION: Anterior cruciate ligament ruptures are frequent, especially in sports. Surgical reconstruction with autologous grafts is widely employed in the international literature. Controversies remain with respect to technique variations as continuous research for improvement takes place. One of these variations is the anatomical double bundle technique, which is performed instead of the conventional single bundle technique. More recently, there has been a tendency towards positioning the two bundles through double bone tunnels in the femur and tibia (anatomical reconstruction. OBJECTIVES: To compare, through biomechanical tests, the practice of anatomical double bundle anterior cruciate ligament reconstruction with a patellar graft to conventional single bundle reconstruction with the same amount of patellar graft in a paired experimental cadaver study. METHODS: Nine pairs of male cadaver knees ranging in age from 44 to 63 years were randomized into two groups: group A (single bundle and group B (anatomical reconstruction. Each knee was biomechanically tested under three conditions: intact anterior cruciate ligament, reconstructed anterior cruciate ligament, and injured anterior cruciate ligament. Maximum anterior dislocation, rigidity, and passive internal tibia rotation were recorded with knees submitted to a 100 N horizontal anterior dislocation force applied to the tibia with the knees at 30, 60 and 90 degrees of flexion. RESULTS: There were no differences between the two techniques for any of the measurements by ANOVA tests. CONCLUSION: The technique of anatomical double bundle reconstruction of the anterior cruciate ligament with bone-patellar tendon-bone graft has a similar biomechanical behavior with regard to anterior tibial dislocation, rigidity, and passive internal tibial rotation.

  16. Effects of different initial bundle tensioning strategies on the outcome of double-bundle ACL reconstruction: a cohort study

    Directory of Open Access Journals (Sweden)

    Muneta Takeshi

    2011-07-01

    Full Text Available Abstract Background This study was performed to investigate the effects of different strategies and initial tension applied to each one of the bundles, antero-medial (AM and postero-lateral (PL, on clinical outcome in double bundle (DB ACL reconstruction. Methods One hundred fifty-one primary unilateral DB ACL reconstructions performed by a single surgeon from 1994 through 2002 were included in the study with a follow-up of at least 24 months. They were divided in the following 3 groups: Group I - Higher initial tension applied manually in the AM bundle compared to PL. II - Higher tension applied in the PL bundle compared to AM. III - The 2 bundles were attempted to be equally tensioned. All fixations were performed in 30 degrees of flexion. Group I = 59 patients, group II = 53 patients and group III = 39 patients. The groups had no statistical differences concerning demographic distribution. Clinical outcome was retrospectively evaluated by use of knee range of motion, manual knee laxity tests, KT-1000, Lysholm knee scale, subjective recovery scale and sports performance recovery scale. The differences of data were analyzed among the three groups. Results Group I showed a significant extension deficit compared with groups II and III. ANOVA revealed a significant difference of anterior laxity measured by the KT-1000 (average KT difference of 2.1, 2.1 and 1.2 mm in Group I, II and III, respectively. A statistical difference was found among the three groups regarding subjective and sports performance recovery scales with Group II showing higher scores in recovery than Group I. Conclusions The current clinical study does not recommend manual maximum of initial tension applied to the anteromedial or posterolateral bundles with graft tension imbalance at 30 degrees of flexion in double-bundle ACL reconstruction to achieve a better clinical outcome.

  17. Single axon branching analysis in rat thalamocortical projection from the anteroventral thalamus to the granular retrosplenial cortex

    Directory of Open Access Journals (Sweden)

    Saori eOdagiri

    2011-10-01

    Full Text Available The granular retrosplenial cortex (GRS in the rat has a distinct microcoluimn-type structure. The apical tufts of dendritic bundles at layer I, which are formed by layer II neurons, co-localize with patches of thalamic terminations from anteroventral thalamic nucleus (AV. To further understand this microcolumn-type structure in the GRS, one of remaining questions is whether this structure extends into other layers, such as layers III/IV. Other than layer I, previous tracer injection study showed that AV thalamic nucleus also projects to layer III/IV in the GRS. In this study, we examined the morphology of branches in the GRS from the AV thalamus in single axon branch resolution in order to determine whether AV axon branches in layer III/IV are branches of axons with extensive branch in layer I, and, if so, whether the extent of these arborizations in layer III/IV vertically matches with that in layer I. For this purpose, we used a small volume injection of biotinylated dextran-amine into the AV thalamus and reconstructing labeled single axon branches in the GRS. We found that the AV axons consisted of heterogeneous branching types. Type 1 had extensive arborization occurring only in layer Ia. Type 2 had additional branches in III/IV. Types 1 and 2 had extensive ramifications in layer Ia, with lateral extensions within the previously reported extensions of tufts from single dendritic bundles (i.e., 30-200 µm; mean 78 µm. In type 2 branches, axon arborizations in layer III/IV were just below to layer Ia ramifications, but much wider (148-533 µm: mean, 341 µm than that in layer Ia axon branches and dendritic bundles, suggesting that layer-specific information transmission spacing existed even from the same single axons from the AV to the GRS. Thus, microcolumn-type structure in the upper layer of the GRS was not strictly continuous from layer I to layer IV. How each layer and its components interact each other in different spatial scale should

  18. The 2-Hilbert space of a prequantum bundle gerbe

    Science.gov (United States)

    Bunk, Severin; Sämann, Christian; Szabo, Richard J.

    We construct a prequantum 2-Hilbert space for any line bundle gerbe whose Dixmier-Douady class is torsion. Analogously to usual prequantization, this 2-Hilbert space has the category of sections of the line bundle gerbe as its underlying 2-vector space. These sections are obtained as certain morphism categories in Waldorf’s version of the 2-category of line bundle gerbes. We show that these morphism categories carry a monoidal structure under which they are semisimple and abelian. We introduce a dual functor on the sections, which yields a closed structure on the morphisms between bundle gerbes and turns the category of sections into a 2-Hilbert space. We discuss how these 2-Hilbert spaces fit various expectations from higher prequantization. We then extend the transgression functor to the full 2-category of bundle gerbes and demonstrate its compatibility with the additional structures introduced. We discuss various aspects of Kostant-Souriau prequantization in this setting, including its dimensional reduction to ordinary prequantization.

  19. Improvements to Wire Bundle Thermal Modeling for Ampacity Determination

    Science.gov (United States)

    Rickman, Steve L.; Iannello, Christopher J.; Shariff, Khadijah

    2017-01-01

    Determining current carrying capacity (ampacity) of wire bundles in aerospace vehicles is critical not only to safety but also to efficient design. Published standards provide guidance on determining wire bundle ampacity but offer little flexibility for configurations where wire bundles of mixed gauges and currents are employed with varying external insulation jacket surface properties. Thermal modeling has been employed in an attempt to develop techniques to assist in ampacity determination for these complex configurations. Previous developments allowed analysis of wire bundle configurations but was constrained to configurations comprised of less than 50 elements. Additionally, for vacuum analyses, configurations with very low emittance external jackets suffered from numerical instability in the solution. A new thermal modeler is presented allowing for larger configurations and is not constrained for low bundle infrared emissivity calculations. Formulation of key internal radiation and interface conductance parameters is discussed including the effects of temperature and air pressure on wire to wire thermal conductance. Test cases comparing model-predicted ampacity and that calculated from standards documents are presented.

  20. Anatomy of an Oligourea Six-Helix Bundle.

    Science.gov (United States)

    Lombardo, Caterina M; Collie, Gavin W; Pulka-Ziach, Karolina; Rosu, Frederic; Gabelica, Valerie; Mackereth, Cameron D; Guichard, Gilles

    2016-08-24

    Non-natural synthetic oligomers that adopt well-defined secondary structures (i.e., foldamers) represent appealing components for the fabrication of bioinspired self-assembled architectures at the nanometer scale. Recently, peptidomimetic N,N'-linked oligourea helices have been designed de novo with the ability to fold into discrete helix bundles in aqueous conditions. In order to gain better insight into the determinants of oligourea helix bundle formation, we have investigated the sequence-to-structure relationship of an 11-mer oligourea previously shown to assemble into a six-helix bundle. Using circular dichroism, NMR spectroscopy, native mass-spectrometry and X-ray crystallography, we studied how bundle formation was affected by systematic replacement of the hydrophobic surface of the oligourea helix with either polar or different hydrophobic side chains. The molecular information gathered here has revealed several key requirements for foldamer bundle formation in aqueous conditions, and provides valuable insight toward the development of foldamer quaternary assemblies with improved (bio)physical properties and divergent topologies.

  1. Ecosystem service bundles for analyzing tradeoffs in diverse landscapes

    Science.gov (United States)

    Raudsepp-Hearne, C.; Peterson, G. D.; Bennett, E. M.

    2010-01-01

    A key challenge of ecosystem management is determining how to manage multiple ecosystem services across landscapes. Enhancing important provisioning ecosystem services, such as food and timber, often leads to tradeoffs between regulating and cultural ecosystem services, such as nutrient cycling, flood protection, and tourism. We developed a framework for analyzing the provision of multiple ecosystem services across landscapes and present an empirical demonstration of ecosystem service bundles, sets of services that appear together repeatedly. Ecosystem service bundles were identified by analyzing the spatial patterns of 12 ecosystem services in a mixed-use landscape consisting of 137 municipalities in Quebec, Canada. We identified six types of ecosystem service bundles and were able to link these bundles to areas on the landscape characterized by distinct social–ecological dynamics. Our results show landscape-scale tradeoffs between provisioning and almost all regulating and cultural ecosystem services, and they show that a greater diversity of ecosystem services is positively correlated with the provision of regulating ecosystem services. Ecosystem service-bundle analysis can identify areas on a landscape where ecosystem management has produced exceptionally desirable or undesirable sets of ecosystem services. PMID:20194739

  2. Syntheses of Nanostructure Bundles Based on Semiconducting Metal Silicides

    Science.gov (United States)

    Li, Wen; Ishikawa, Daisuke; Tatsuoka, Hirokazu

    2013-08-01

    A variety of nanostructure bundles and arrays based on semiconducting metal silicides have been synthesized using abundant and non-toxic starting materials. Three types of fabrication techniques of the nanostructure bundles or arrays, including direct growth, template synthesis using natural nanostructured materials and template synthesis using artificially fabricated nanostructured materials are demonstrated. CrSi2 nanowire bundles were directly grown by the exposure of Si substrates to CrCl2 vapor at atmospheric pressure. A hexagonal MoSi2 nanosheet, Mg2Si/MgO composite nanowire and Mg2Si nanowire bundles and MnSi1.7 nanowire array were synthesized using a MoS2 layered material, a SiOx nanofiber bundle, a Si nanowire array, and a Si nanowire array as the templates, respectively. Additionally, the fabrication phenomenon and structural properties of the nanostructured semiconducting metal silicides were investigated. These reactions provided the low-cost and controllable synthetic techniques to synthesize large scale and one-dimensional semiconducting metal silicides for thermoelectric applications.

  3. A prospective comparative study of clinical and functional outcomes between anatomic double bundle and single bundle hamstring grafts for arthroscopic anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Morey, Vivek M; Nag, Hira Lal; Chowdhury, Buddhadev; Sankineani, Sukesh Rao; Naranje, Sameer M

    2015-09-01

    Despite a number of studies comparing postoperative stability and function after anatomic single bundle and double bundle anterior cruciate ligament reconstruction, it remains unclear whether double bundle reconstruction has better functional outcome than single bundle anterior cruciate ligament reconstruction. To compare the subjective functional outcome as well as clinical stability in patients treated with either anatomic single bundle or anatomic double bundle anterior cruciate ligament (ACL) reconstruction. We hypothesized that there would be no difference in the postoperative functional outcome and clinical stability between anatomical double bundle anterior cruciate ligament reconstructions when compared to single bundle anterior cruciate ligament reconstructions. We prospectively followed 40 patients out of which, 20 patients were operated for anatomic single bundle ACL reconstruction and other 20 patients underwent anatomic double bundle ACL reconstruction. Patient evaluation using the laxity tests and outcome scales was done preoperatively and at 12, 24 and 48 months after the surgery. Clinical stability was assessed by Lachman test, Pivot shift test and Delhi active test. Functional outcome was assessed by International Knee Documentation Committee (IKDC), Lysholm and Modified Cincinnati scores. Patients in both groups were evaluated at regular intervals for a minimum period of 48 months (mean 51 months, range 48-56 months). For all subjective scores, double bundle group patients reported statistically significant higher scores compared to single bundle group patients. Graded stability results of the Lachman, and Pivot shift tests were significantly higher in the anatomically reconstructed double bundle patient group. We suggest that functional outcome and clinical stability may be better with anatomical double bundle anterior cruciate ligament reconstruction as compared to anatomical single bundle anterior cruciate ligament reconstruction. Copyright

  4. Multiple pathways regulate shoot branching

    Directory of Open Access Journals (Sweden)

    Catherine eRameau

    2015-01-01

    Full Text Available Shoot branching patterns result from the spatio-temporal regulation of axillary bud outgrowth. Numerous endogenous, developmental and environmental factors are integrated at the bud and plant levels to determine numbers of growing shoots. Multiple pathways that converge to common integrators are most probably involved. We propose several pathways involving not only the classical hormones auxin, cytokinins and strigolactones, but also other signals with a strong influence on shoot branching such as gibberellins, sugars or molecular actors of plant phase transition. We also deal with recent findings about the molecular mechanisms and the pathway involved in the response to shade as an example of an environmental signal controlling branching. We propose the TCP transcription factor TB1/BRC1 and the polar auxin transport stream in the stem as possible integrators of these pathways. We finally discuss how modeling can help to represent this highly dynamic system by articulating knowledges and hypothesis and calculating the phenotype properties they imply.

  5. Branch prediction in the pentium family

    DEFF Research Database (Denmark)

    Fog, Agner

    1998-01-01

    How the branch prediction mechanism in the Pentium has been uncovered with all its quirks, and the incredibly more effective branch prediction in the later versions.......How the branch prediction mechanism in the Pentium has been uncovered with all its quirks, and the incredibly more effective branch prediction in the later versions....

  6. Single-Phase Bundle Flows Including Macroscopic Turbulence Model

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Jun; Yoon, Han Young [KAERI, Daejeon (Korea, Republic of); Yoon, Seok Jong; Cho, Hyoung Kyu [Seoul National University, Seoul (Korea, Republic of)

    2016-05-15

    To deal with various thermal hydraulic phenomena due to rapid change of fluid properties when an accident happens, securing mechanistic approaches as much as possible may reduce the uncertainty arising from improper applications of the experimental models. In this study, the turbulence mixing model, which is well defined in the subchannel analysis code such as VIPRE, COBRA, and MATRA by experiments, is replaced by a macroscopic k-e turbulence model, which represents the aspect of mathematical derivation. The performance of CUPID with macroscopic turbulence model is validated against several bundle experiments: CNEN 4x4 and PNL 7x7 rod bundle tests. In this study, the macroscopic k-e model has been validated for the application to subchannel analysis. It has been implemented in the CUPID code and validated against CNEN 4x4 and PNL 7x7 rod bundle tests. The results showed that the macroscopic k-e turbulence model can estimate the experiments properly.

  7. Symposium on Singularities, Representation of Algebras, and Vector Bundles

    CERN Document Server

    Trautmann, Günther

    1987-01-01

    It is well known that there are close relations between classes of singularities and representation theory via the McKay correspondence and between representation theory and vector bundles on projective spaces via the Bernstein-Gelfand-Gelfand construction. These relations however cannot be considered to be either completely understood or fully exploited. These proceedings document recent developments in the area. The questions and methods of representation theory have applications to singularities and to vector bundles. Representation theory itself, which had primarily developed its methods for Artinian algebras, starts to investigate algebras of higher dimension partly because of these applications. Future research in representation theory may be spurred by the classification of singularities and the highly developed theory of moduli for vector bundles. The volume contains 3 survey articles on the 3 main topics mentioned, stressing their interrelationships, as well as original research papers.

  8. Narrow muon bundles from muon pair production in rock

    CERN Document Server

    Kudryavtsev, V A; Spooner, N J C

    1999-01-01

    We revise the process of muon pair production by high-energy muons in rock using the recently published cross-section. The three- dimensional Monte Carlo code MUSIC has been used to obtain the characteristics of the muon bundles initiated via this process. We have compared them with those of conventional muon bundles initiated in the atmosphere and shown that large underground detectors, capable of collecting hundreds of thousands of multiple muon events, can discriminate statistically muon induced bundles from conventional ones. However, we find that the enhancement of the measured muon decoherence function over that predicted at small distances, recently reported by the MACRO experiment, cannot be explained by the effect of muon pair production alone, unless its cross-section is underestimated by a factor of 3. (20 refs).

  9. Product bundling as a customer loyalty strategy; Kundenbindung durch Produktbuendel

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, H.G. [Arthur Andersen Business Consulting GmbH, Duesseldorf (Germany)

    2000-12-01

    In the deregulated market in electricity, all marketers and energy-related service providers are competing not only for new customers, but also for customer loyalty. The article sets out concepts and strategies developed by a business consulting firm, for maintaing or enhancing customer loyalty in the end-use market segment, focusing on customized product bundling. A four-tier approach for product bundle development and implementation is discussed. (orig./CB) [German] Fuer Energieversorger und -dienstleister ergibt sich neben der Neukundengewinnung der strategische Zwang zur Bindung bestehender Kunden. An praktischen Ansaetzen fuer Privatkunden stehen neben Value-Added-Services und Incentives (Kundenclub, -karte) nicht zuletzt Produktbuendel (Bundles) zur Verfuegung. Zur erfolgreichen Entwicklung und Implementierung von Produktbuendeln wird ein vierphasiges Vorgehensmodell erlaeutert. (orig./CB)

  10. Measurement of secondary flow vortices on a rod bundle

    Energy Technology Data Exchange (ETDEWEB)

    Vonka, V.

    1988-02-01

    Secondary flow vortices in infinite rod bundles have been predicted by a number of theoretical analyses. Nevertheless experimental verification was difficult, since the magnitude of the secondary velocities appeared to be less than the accuracy of the experimental techniques used. Only indications of the maximum velocity magnitude have been available but no report on successful direct measurement is known to the author. At ECN, laser Doppler velocimetry is successfully used for measurement of secondary flow vortices in two regular subchannels of a triangularly arranged bare rod bundle with pitch-to-diameter ratio P/D-1.3 under the Reynolds number conditions 60,000 and 175,000. One single secondary vortex, having the average tangential velocity slightly less than 0.1% of the mean bulk velocity, is resolved per minimum symmetry sector of the bundle geometry. Ensemble averages are made to obtain quantitative description of the vortex and to form a data base for comparison with calculations.

  11. Gradient Bundle Analysis: A Full Topological Approach to Chemical Bonding

    CERN Document Server

    Morgenstern, Amanda

    2016-01-01

    The "chemical bond" is a central concept in molecular sciences, but there is no consensus as to what a bond actually is. Therefore, a variety of bonding models have been developed, each defining the structure of molecules in a different manner with the goal of explaining and predicting chemical properties. This thesis describes the initial development of gradient bundle analysis (GBA), a chemical bonding model that creates a high resolution picture of chemical interactions within the charge density framework. GBA is based on concepts from the quantum theory of atoms in molecules (QTAIM), but uses a more complete picture of the topology and geometry of the electron charge density to understand and predict bonding interactions. Gradient bundles are defined as volumes bounded by zero-flux surfaces (ZFSs) in the gradient of the charge density with well-defined energies. The structure of gradient bundles provides an avenue for detecting the locations of valence electrons, which correspond to reactive regions in a ...

  12. Failure of a MEA reclaimer tube bundle due to corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Shaban, H.; Abdo, M.S.E.; Lal, D.P.

    1988-08-01

    The removal of sulphur compounds from natural gas used in ammonia production is carried out by scrubbing with monoethanol amine (MEA). To avoid build up of corrosion and degradation products, a portion of the circulating MEA solution is passed through a reclaimer. This is essentially a kettle-type reboiler with a tube bundle made of 316L stainless steel. Occasional failures of the tube bundle due to pitting corrosion have been reported. It is suggested that the excessive pitting corrosion observed on the upper rows of the tube bundle could be partly due to high steam temperature but mainly due to the liquid level falling below the tubes leaving an accumulation of corrosive degradation products on the exposed surfaces, normally these corrosive products remain diluted in the MEA solution and cause little corrosion of the covered tubes. Their concentration on the dry upper layers of the hot metal tubes, however, leads to excessive corrosion. (U.K.).

  13. Designing cooperatively folded abiotic uni- and multimolecular helix bundles

    Science.gov (United States)

    de, Soumen; Chi, Bo; Granier, Thierry; Qi, Ting; Maurizot, Victor; Huc, Ivan

    2018-01-01

    Abiotic foldamers, that is foldamers that have backbones chemically remote from peptidic and nucleotidic skeletons, may give access to shapes and functions different to those of peptides and nucleotides. However, design methodologies towards abiotic tertiary and quaternary structures are yet to be developed. Here we report rationally designed interactional patterns to guide the folding and assembly of abiotic helix bundles. Computational design facilitated the introduction of hydrogen-bonding functionalities at defined locations on the aromatic amide backbones that promote cooperative folding into helix-turn-helix motifs in organic solvents. The hydrogen-bond-directed aggregation of helices not linked by a turn unit produced several thermodynamically and kinetically stable homochiral dimeric and trimeric bundles with structures that are distinct from the designed helix-turn-helix. Relative helix orientation within the bundles may be changed from parallel to tilted on subtle solvent variations. Altogether, these results prefigure the richness and uniqueness of abiotic tertiary structure behaviour.

  14. Mechanical Stresses and Forces in Stereocilia Bundles of Inner and Outer Hair Cells

    Science.gov (United States)

    Mueller, R.; Maier, H.; Boehnke, F.; Arnold, W.

    2003-02-01

    The precise mechanism of mechanoelectrical transduction in stereocilia bundles is not known. It is very difficult to measure the extremely small stresses, which occur at the stereocilia bundles. Therefore we developed 3-D finite element models of stereocilia bundles (guinea pig) to obtain quantitative results. The stereocilia bundles of the outer hair cells show a characteristic W-form. Therefore, it is interesting to compare the mechanical behavior of the stereocilia bundle of an outer hair cell with that of an inner hair cell with its linear arrangement. Our analysis provides estimates of forces and stresses on the transducer channels of mammalian hair bundles, although the model does not include active mechanisms yet.

  15. The Analysis of SBWR Critical Power Bundle Using Cobrag Code

    Directory of Open Access Journals (Sweden)

    Yohannes Sardjono

    2013-03-01

    Full Text Available The coolant mechanism of SBWR is similar with the Dodewaard Nuclear Power Plant (NPP in the Netherlands that first went critical in 1968. The similarity of both NPP is cooled by natural convection system. These coolant concept is very related with same parameters on fuel bundle design especially fuel bundle length, core pressure drop and core flow rate as well as critical power bundle. The analysis was carried out by using COBRAG computer code. COBRAG computer code is GE Company proprietary. Basically COBRAG computer code is a tool to solve compressible three-dimensional, two fluid, three field equations for two phase flow. The three fields are the vapor field, the continuous liquid field, and the liquid drop field. This code has been applied to analyses model flow and heat transfer within the reactor core. This volume describes the finitevolume equations and the numerical solution methods used to solve these equations. This analysis of same parameters has been done i.e.; inlet sub cooling 20 BTU/lbm and 40 BTU/lbm, 1000 psi pressure and R-factor is 1.038, mass flux are 0.5 Mlb/hr.ft2, 0.75 Mlb/hr.ft2, 1.00 Mlb/hr.ft2 and 1.25 Mlb/hr.ft2. Those conditions based on history operation of some type of the cell fuel bundle line at GE Nuclear Energy. According to the results, it can be concluded that SBWR critical power bundle is 10.5 % less than current BWR critical power bundle with length reduction of 12 ft to 9 ft.

  16. Learning Bundled Care Opportunities from Electronic Medical Records.

    Science.gov (United States)

    Chen, You; Kho, Abel N; Liebovitz, David; Ivory, Catherine; Osmundson, Sarah; Bian, Jiang; Malin, Bradley A

    2017-11-22

    The traditional fee-for-service approach to healthcare can lead to the management of a patient's conditions in a siloed manner, inducing various negative consequences. It has been recognized that a bundled approach to healthcare - one that manages a collection of health conditions together - may enable greater efficacy and cost savings. However, it is not always evident which sets of conditions should be managed in a bundled manner. In this study, we investigate if a data-driven approach can automatically learn potential bundles. We designed a framework to infer health condition collections (HCCs) based on the similarity of their clinical workflows, according to electronic medical record (EMR) utilization. We evaluated the framework with data from over 16,500 inpatient stays from Northwestern Memorial Hospital in Chicago, Illinois. The plausibility of the inferred HCCs for bundled care was assessed through an online survey of a panel of five experts, whose responses were analyzed via an analysis of variance (ANOVA) at a 95% confidence level. We further assessed the face validity of the HCCs using evidence in the published literature. The framework inferred four HCCs, indicative of 1) fetal abnormalities, 2) late pregnancies, 3) prostate problems, and 4) chronic diseases, with congestive heart failure featuring prominently. Each HCC was substantiated with evidence in the literature and was deemed plausible for bundled care by the experts at a statistically significant level. The findings suggest that an automated EMR data-driven framework conducted can provide a basis for discovering bundled care opportunities. Still, translating such findings into actual care management will require further refinement, implementation, and evaluation. Copyright © 2017. Published by Elsevier Inc.

  17. Types of Heart Block

    Science.gov (United States)

    ... defects. Acquired heart block is more common than congenital heart block. Damage to the heart muscle or its electrical system causes acquired heart block. Diseases, surgery, or medicines can cause this damage. The three types of heart block are first degree, second degree, ...

  18. What Causes Heart Block?

    Science.gov (United States)

    ... defects. Acquired heart block is more common than congenital heart block. Damage to the heart muscle or its electrical system causes acquired heart block. Diseases, surgery, or medicines can cause this damage. The three types of heart block are first degree, second degree, ...

  19. Living with Heart Block

    Science.gov (United States)

    ... defects. Acquired heart block is more common than congenital heart block. Damage to the heart muscle or its electrical system causes acquired heart block. Diseases, surgery, or medicines can cause this damage. The three types of heart block are first degree, second degree, ...

  20. Fast bundle algorithm for multiple-instance learning.

    Science.gov (United States)

    Bergeron, Charles; Moore, Gregory; Zaretzki, Jed; Breneman, Curt M; Bennett, Kristin P

    2012-06-01

    We present a bundle algorithm for multiple-instance classification and ranking. These frameworks yield improved models on many problems possessing special structure. Multiple-instance loss functions are typically nonsmooth and nonconvex, and current algorithms convert these to smooth nonconvex optimization problems that are solved iteratively. Inspired by the latest linear-time subgradient-based methods for support vector machines, we optimize the objective directly using a nonconvex bundle method. Computational results show this method is linearly scalable, while not sacrificing generalization accuracy, permitting modeling on new and larger data sets in computational chemistry and other applications. This new implementation facilitates modeling with kernels.

  1. Cellulosic Fibers: Effect of Processing on Fiber Bundle Strength

    DEFF Research Database (Denmark)

    Thygesen, Anders; Madsen, Bo; Thomsen, Anne Belinda

    2011-01-01

    A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding, and cotto......A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding...

  2. On a Lie Algebraic Characterization of Vector Bundles

    Directory of Open Access Journals (Sweden)

    Pierre B.A. Lecomte

    2012-01-01

    Full Text Available We prove that a vector bundle π: E→M is characterized by the Lie algebra generated by all differential operators on E which are eigenvectors of the Lie derivative in the direction of the Euler vector field. Our result is of Pursell-Shanks type but it is remarkable in the sense that it is the whole fibration that is characterized here. The proof relies on a theorem of [Lecomte P., J. Math. Pures Appl. (9 60 (1981, 229-239] and inherits the same hypotheses. In particular, our characterization holds only for vector bundles of rank greater than 1.

  3. National Zoological Park Branch Library.

    Science.gov (United States)

    Kenyon, Kay A.

    1988-01-01

    Describes the functions of the National Zoological Park Branch of the Smithsonian Institution Libraries, which is dedicated to supporting the special information needs of the zoo. Topics covered include the library's history, collection, programs, services, future plans, and relations with other zoo libraries. (two references) (Author/CLB)

  4. Branching diffusion with particle interactions

    OpenAIRE

    Engländer, János; Zhang, Liang

    2016-01-01

    A $d$-dimensional branching diffusion, $Z$, is investigated, where the linear attraction or repulsion between particles is competing with an Ornstein-Uhlenbeck drift, with parameter $b$ (we take $b>0$ for inward O-U and $b0$) or repulsion ($\\gamma 0$, while escapes to infinity exponentially fast (rate $|b|$) when $b

  5. Risk Factor Assessment Branch (RFAB)

    Science.gov (United States)

    The Risk Factor Assessment Branch (RFAB) focuses on the development, evaluation, and dissemination of high-quality risk factor metrics, methods, tools, technologies, and resources for use across the cancer research continuum, and the assessment of cancer-related risk factors in the population.

  6. Quantitative Analysis of Axonal Branch Dynamics in the Developing Nervous System.

    Directory of Open Access Journals (Sweden)

    Kelsey Chalmers

    2016-03-01

    Full Text Available Branching is an important mechanism by which axons navigate to their targets during neural development. For instance, in the developing zebrafish retinotectal system, selective branching plays a critical role during both initial pathfinding and subsequent arborisation once the target zone has been reached. Here we show how quantitative methods can help extract new information from time-lapse imaging about the nature of the underlying branch dynamics. First, we introduce Dynamic Time Warping to this domain as a method for automatically matching branches between frames, replacing the effort required for manual matching. Second, we model branch dynamics as a birth-death process, i.e. a special case of a continuous-time Markov process. This reveals that the birth rate for branches from zebrafish retinotectal axons, as they navigate across the tectum, increased over time. We observed no significant change in the death rate for branches over this time period. However, blocking neuronal activity with TTX slightly increased the death rate, without a detectable change in the birth rate. Third, we show how the extraction of these rates allows computational simulations of branch dynamics whose statistics closely match the data. Together these results reveal new aspects of the biology of retinotectal pathfinding, and introduce computational techniques which are applicable to the study of axon branching more generally.

  7. Quantitative Analysis of Axonal Branch Dynamics in the Developing Nervous System

    Science.gov (United States)

    Scott, Ethan K.; Goodhill, Geoffrey J.

    2016-01-01

    Branching is an important mechanism by which axons navigate to their targets during neural development. For instance, in the developing zebrafish retinotectal system, selective branching plays a critical role during both initial pathfinding and subsequent arborisation once the target zone has been reached. Here we show how quantitative methods can help extract new information from time-lapse imaging about the nature of the underlying branch dynamics. First, we introduce Dynamic Time Warping to this domain as a method for automatically matching branches between frames, replacing the effort required for manual matching. Second, we model branch dynamics as a birth-death process, i.e. a special case of a continuous-time Markov process. This reveals that the birth rate for branches from zebrafish retinotectal axons, as they navigate across the tectum, increased over time. We observed no significant change in the death rate for branches over this time period. However, blocking neuronal activity with TTX slightly increased the death rate, without a detectable change in the birth rate. Third, we show how the extraction of these rates allows computational simulations of branch dynamics whose statistics closely match the data. Together these results reveal new aspects of the biology of retinotectal pathfinding, and introduce computational techniques which are applicable to the study of axon branching more generally. PMID:26998842

  8. Quantitative Analysis of Axonal Branch Dynamics in the Developing Nervous System.

    Science.gov (United States)

    Chalmers, Kelsey; Kita, Elizabeth M; Scott, Ethan K; Goodhill, Geoffrey J

    2016-03-01

    Branching is an important mechanism by which axons navigate to their targets during neural development. For instance, in the developing zebrafish retinotectal system, selective branching plays a critical role during both initial pathfinding and subsequent arborisation once the target zone has been reached. Here we show how quantitative methods can help extract new information from time-lapse imaging about the nature of the underlying branch dynamics. First, we introduce Dynamic Time Warping to this domain as a method for automatically matching branches between frames, replacing the effort required for manual matching. Second, we model branch dynamics as a birth-death process, i.e. a special case of a continuous-time Markov process. This reveals that the birth rate for branches from zebrafish retinotectal axons, as they navigate across the tectum, increased over time. We observed no significant change in the death rate for branches over this time period. However, blocking neuronal activity with TTX slightly increased the death rate, without a detectable change in the birth rate. Third, we show how the extraction of these rates allows computational simulations of branch dynamics whose statistics closely match the data. Together these results reveal new aspects of the biology of retinotectal pathfinding, and introduce computational techniques which are applicable to the study of axon branching more generally.

  9. Variant Anatomy of the Nasal and Labial Branches of the Infraorbital Nerve.

    Science.gov (United States)

    Nderitu, Joseph Munyiri; Butt, Fawzia; Saidi, Hassan

    2016-11-01

    Comprehensive understanding of the variations in the branches of the infraorbital nerve (ION) is vital to the prevention of iatrogenic nerve injury and successful ION blockade during orbitozygomatic facial procedures. Only a few studies exist on the variant anatomy of the branching patterns of this nerve. This article provides a detailed description of the variations of the nasal and superior labial branches of the ION. This study was performed on 84 IONs by dissecting 42 formalin-fixed cadavers from the Laboratory of Topographic Anatomy, Department of Human Anatomy, University of Nairobi. The branches were exposed at their origin and followed to their termination. The findings included variant emergence patterns, anomalous course, and absence as well as extra branches. It was noted that the external nasal nerve was absent in 34.53% cases. There were common trunks between the internal and external nasal nerves and cases of communication between branches of these nerves were also noted. Accessory superior labial nerves were present in 9.52% of the nerves. This detailed study reveals additional variations in the emergence and branching pattern of the ION. Caution is imperative during orbitozygomatic facial surgery to prevent injury to these branches. These variations also underlie the lack of response to surgical treatment for trigeminal neuralgia and also the need for a filtration to achieve full anesthesia after ION block. In addition, the extra branches identified raise the prospects of using these nerves for grafting purposes if their precise patterns are determined.

  10. EXTERNAL VERIFICATION OF THE BUNDLE ADJUSTMENT IN PHOTOGRAMMETRIC SOFTWARE USING THE DAMPED BUNDLE ADJUSTMENT TOOLBOX

    Directory of Open Access Journals (Sweden)

    N. Börlin

    2016-06-01

    Full Text Available The aim of this paper is to investigate whether the Matlab-based Damped Bundle Adjustment Toolbox (DBAT can be used to provide independent verification of the BA computation of two popular software—PhotoModeler (PM and PhotoScan (PS. For frame camera data sets with lens distortion, DBAT is able to reprocess and replicate subsets of PM results with high accuracy. For lens-distortion-free data sets, DBAT can furthermore provide comparative results between PM and PS. Data sets for the discussed projects are available from the authors. The use of an external verification tool such as DBAT will enable users to get an independent verification of the computations of their software. In addition, DBAT can provide computation of quality parameters such as estimated standard deviations, correlation between parameters, etc., something that should be part of best practice for any photogrammetric software. Finally, as the code is free and open-source, users can add computations of their own.

  11. Innovative Defense Acquisition Concept Deployer Equipment Bundle (DEB)

    Science.gov (United States)

    2017-06-01

    METHODOLOGY This project reviewed a substantial amount of literature , to include applicable concept plans, memorandums, cost benefit analyses, organizational...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA MBA PROFESSIONAL REPORT INNOVATIVE DEFENSE ACQUISITION CONCEPT DEPLOYER...ACQUISITION CONCEPT DEPLOYER EQUIPMENT BUNDLE (DEB) 5. FUNDING NUMBERS 6. AUTHOR(S) Frederic Albesa, Isaac J. Ortman, and Stephen F. Kirouac 7

  12. Temperature response of bundle-sheath conductance in maize leaves

    NARCIS (Netherlands)

    Yin, Xinyou; Putten, Van Der Peter E.L.; Struik, Paul C.; Driever, Steven M.

    2016-01-01

    A small bundle-sheath conductance (g bs) is essential for the C4 CO2-concentrating mechanism to suppress photorespiration effectively. To predict the productivity of C4 crops accurately under global warming, it is necessary to examine whether and how g

  13. Quillen bundle and geometric prequantization of non-abelian ...

    Indian Academy of Sciences (India)

    E-mail: rkmn@mri.ernet.in; rukmini.dey@gmail.com; smr@bose.res.in. MS received 7 September 2010; revised 23 November 2010. Abstract. In this paper we prequantize the moduli space of non-abelian vortices. We explicitly calculate the symplectic form arising from L2 metric and we construct a prequantum line bundle ...

  14. Multicell slug flow heat transfer analysis of finite LMFBR bundles

    Energy Technology Data Exchange (ETDEWEB)

    Yeung, M.K.; Wolf, L.

    1978-12-01

    An analytical two-dimensional, multi-region, multi-cell technique has been developed for the thermal analysis of LMFBR rod bundles. Local temperature fields of various unit cells were obtained for 7, 19, and 37-rod bundles of different geometries and power distributions. The validity of the technique has been verified by its excellent agreement with the THTB calculational result. By comparing the calculated fully-developed circumferential clad temperature distribution with those of the experimental measurements, an axial correction factor has been derived to account for the entrance effect for practical considerations. Moreover, the knowledge of the local temperature field of the rod bundle leads to the determination of the effective mixing lengths L/sub ij/ for adjacent subchannels of various geometries. It was shown that the implementation of the accurately determined L/sub ij/ into COBRA-IIIC calculations has fairly significant effects on intersubchannel mixing. In addition, a scheme has been proposed to couple the 2-D distributed and lumped parameter calculation by COBRA-IIIC such that the entrance effect can be implanted into the distributed parameter analysis. The technique has demonstrated its applicability for a 7-rod bundle and the results of calculation were compared to those of three-dimensional analyses and experimental measurements.

  15. Metallic/semiconducting ratio of carbon nanotubes in a bundle ...

    Indian Academy of Sciences (India)

    SWCNTs) in a bundle by resonant Raman spectroscopy. The calculation has been done for the three peak positions in radial breathing mode (RBM) spectra obtained by using a laser excitation wavelength () of 633 nm from He–Ne laser on ...

  16. The fibre bundle anatomy of human cruciate ligaments

    NARCIS (Netherlands)

    Mommersteeg, T. J.; Kooloos, J. G.; Blankevoort, L.; Kauer, J. M.; Huiskes, R.; Roeling, F. Q.

    1995-01-01

    The cruciate ligaments of the knee consist of numerous fascicles, groups of which comprise fibre bundles. The stabilising function of these ligaments is established by changes in the lengths and orientations of the fascicles. Understanding the function of knee ligaments thus requires an

  17. Metabolic profiling of laser microdissected vascular bundles of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Fiehn Oliver

    2005-08-01

    Full Text Available Abstract Background Laser microdissection is a useful tool for collecting tissue-specific samples or even single cells from animal and plant tissue sections. This technique has been successfully employed to study cell type-specific expression at the RNA, and more recently also at the protein level. However, metabolites were not amenable to analysis after laser microdissection, due to the procedures routinely applied for sample preparation. Using standard tissue fixation and embedding protocols to prepare histological sections, metabolites are either efficiently extracted by dehydrating solvents, or washed out by embedding agents. Results In this study, we used cryosectioning as an alternative method that preserves sufficient cellular structure while minimizing metabolite loss by excluding any solute exchange steps. Using this pre-treatment procedure, Arabidopsis thaliana stem sections were prepared for laser microdissection of vascular bundles. Collected samples were subsequently analyzed by gas chromatography-time of flight mass spectrometry (GC-TOF MS to obtain metabolite profiles. From 100 collected vascular bundles (~5,000 cells, 68 metabolites could be identified. More than half of the identified metabolites could be shown to be enriched or depleted in vascular bundles as compared to the surrounding tissues. Conclusion This study uses the example of vascular bundles to demonstrate for the first time that it is possible to analyze a comprehensive set of metabolites from laser microdissected samples at a tissue-specific level, given that a suitable sample preparation procedure is used.

  18. AdS 3-manifolds and Higgs bundles

    DEFF Research Database (Denmark)

    Alessandrini, Daniele; Li, Qiongling

    2017-01-01

    In this paper we investigate the relationships between closed AdS $3$-manifolds and Higgs bundles. We have a new way to construct AdS structures that allows us to see many of their properties explicitly, for example we can recover the very recent formula by Tholozan for their volume. We give natu...

  19. Heat transfer and fluid friction in bundles of twisted tubes

    Science.gov (United States)

    Dzyubenko, B. V.; Dreitser, G. A.

    1986-06-01

    The results of heat-transfer and friction studies in bundles of twisted tubes and rods with spiral wire-wrap spacers are analyzed, and recommendations are given for calculating the heat-transfer coefficient in heat exchangers using twisted tubes.

  20. Fission yeast Scp3 potentially maintains microtubule orientation through bundling.

    Directory of Open Access Journals (Sweden)

    Kanako Ozaki

    Full Text Available Microtubules play important roles in organelle transport, the maintenance of cell polarity and chromosome segregation and generally form bundles during these processes. The fission yeast gene scp3+ was identified as a multicopy suppressor of the cps3-81 mutant, which is hypersensitive to isopropyl N-3-chlorophenylcarbamate (CIPC, a poison that induces abnormal multipolar spindle formation in higher eukaryotes. In this study, we investigated the function of Scp3 along with the effect of CIPC in the fission yeast Schizosaccharomyces pombe. Microscopic observation revealed that treatment with CIPC, cps3-81 mutation and scp3+ gene deletion disturbed the orientation of microtubules in interphase cells. Overexpression of scp3+ suppressed the abnormal orientation of microtubules by promoting bundling. Functional analysis suggested that Scp3 functions independently from Ase1, a protein largely required for the bundling of the mitotic spindle. A strain lacking the ase1+ gene was more sensitive to CIPC, with the drug affecting the integrity of the mitotic spindle, indicating that CIPC has a mitotic target that has a role redundant with Ase1. These results suggested that multiple systems are independently involved to ensure microtubule orientation by bundling in fission yeast.