bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long‐Term Effects of Biatrial Synchronous Pacing to Prevent Drug‐Refractory Atrial Tachyarrhythmia: A Nine‐Year Experience
Authors: D'ALLONNES GILLES REVAULT , PAVIN DOMINIQUE , LECLERCQ CHRISTOPHE , ECKE JEAN EMMANUEL , JAUVERT GAEL , MABO PHILIPPE , DAUBERT JEAN‐CLAUDE 
Published: April 2007

Biatrial Pacing for Atrial Tachyarrhythmia Prevention. Introduction. Results of previous studies suggest that atrial resynchronization by multisite atrial pacing may coutribute to prevention of recurrences in patients with drug‐refractory atrial tachyarrbythmias and significant intra‐atrial conduction delay.Methods and Results. To verify this hypothesis, a prospective noncontrolled study of 86 patients (mean age 66 ± 10 years) was conducted in a single center between January 1989 and February 1998. Inclusion criteria were P wave duration ≥120 msec with interatrial conduction time ≥100 msec, and history of multiple recurrences of atrial tacbyarrbythmias (mean 7 ± 4.8 episodes) evolving in a persistent mode for at least 6 montbs despite optimized drug treatment (mean 2.7 ± 1.8 drugs/patient). Patients were chronically implanted with a pacing system that ensured permanent biatrial pacing using two atrial leads, one placed in the high right atrium and the other one into the mid or the distal part of the coronary sinus. P wave duration decreased from a mean value of 187 ± 29 msec before implant to 106 ± 14 msec (P < 0.0001) under biatrial pacing. After a 33‐month mean follow‐up (range 6 to 109), 55 patients (64%) remained in sinus rhythm, including 28 patients (32.6%) without any documented recurrence and 27 patients with one or more recurrences in a paroxysmal or in a persistent form. In these 55 patients, drug treatment was significantly reduced in relation to the preimplantation period (1.4 ± 0.6 vs 1.7 ± 0.5 drugs/patient; P = 0.011). The other 31 patients went into chronic atrial arrhythmia after a mean period of 26 momths. The only predictive factor of positive response was a spontaneous P wave duration ≤160 msec at baseline.Conclusion. The results are consistent with a preventive effect of permanent biatrial pacing on recurrent and drug‐refractory atrial arrhythmias associated with intra‐atrial conduction delay. (J Cardiovasc Electrophy, Vol. 11, pp. 1081‐1091, October 2000)
Dual Chamber Arrhythmia Detection in the Implantable Cardioverter Defibrillator
Authors: DIJKMAN BARBARA , WELLENS HEIN J.J. 
Published: April 2007

Dual Chamber Arrhythmia Detection hy ICD. Introduction. Dual chamber implantable cardioverter detibrillator (ICD) technology extended ICD therapy to more than termination of hemodynamicaly unstable ventricular tachyarrhythmias. It created the basis for dual chamber arrhythmoa management. In which dependable detection is important for treatment and prevention of both ventricular and atrial arrhythmias.Methods and Results. Dual chamber detection algorithms were investigated in two Medironic dual chamber ICDs; the 7250 Jewel AF (33 patients) and the 7217 Gem DR (31 patients). Both ICDS use the same PR Logic algorithm to interpret tachycardia as ventricular tachycardia (VT), supraventricular tachycardia (SVT), or dual (VT+SVT), The accuracy of dual chamber detection was studied in 310 of 1,367 spontaneously occurring tachcardias in which rate criterion only was not sufficient for arrhythmia diagnosis. In 78 epidoses there was a double tachycardia, in 223 episodes. SVT was detected in the VT or veutricular fibrillation zone, and in 9 episodes arrhythmia was detected outside the boundaries of the PR Logic functioning. In 100% of double techycardias the VT was correctly diagonsed and reveived priority treatment. SVT was seen in 59 (19%) episodes diagonsed as VT. The causes of inappropriate detection were (1) algorithm failure (inability to fulfill the PR<RP condition in atrial tacharrhythmias with 1:1 AV conduction, and far‐filed R wave sensing intermittently present during sinus tachycardia); (2) programming settings (atrial fibrillation atrial flutter with ventricular rate above the SVT limit); and (3) algorithm limitations (atrial tachycardia with ventricular rate around the shortest programmable SVT limit and SVT redetection following VT therapy). Programming measures improved detection ability 13 of 59 of inappropriately detected arrhythmias.Conclusion. Dual chamber detection algorithms evaluated in subset of diagnostically difficult arrhythmias allow safe detection of double tachycardias but require further extension and programmability to improve VT:SVT discrimination rules (J Cardiovasc Electrophysiol. Vot. 11. pp. 1105‐1115. October 2000)
Laplacian Electrograms and the Interpretation of Complex Ventricular Activation Patterns During Ventricular Fibrillation
Authors: CORONEL RUBEN , WILMS‐SCHOPMAN FRANCIBN J.G , DE GROOT JORIS R. , JANSE MICHIEL J. , VAN CAPELLE FRANS J.L. , DE BAKKER JACQUES M.T. 
Published: April 2007

Laplacian Electrograms and Ventricular Fihrillation. Introduction. During ventricular fibrillation (VF) interpretation of a local electrogram and determination of the local activation moment are hampered by remote activity or intervening repolarization waves. Successful defibrillation depends on critical timing of the shock relative to local activation. We tested the applicabillity of Laplacian electrograms for detection of the moment of local activation during VF.Methods and Results. From isolated perfased porcine infact heart, 247 local unipolar electrograms were recorded simultaneously (13 × 19 matrix, interelectrode distance 0.3 mm) from the left ventricular wall during sinus rhythm, following pacing or during VF, Activation maps were constructed based on local unipolar electrograms, and Laplacian electrograms were calculated from local electrograms ane its eight neighbors. The Laplacian electrogram displayed a sharp R/S complex with local activation iodicted by the moment of zero crossing without interference from remote activity or repolarization waves. Its amplitude increased with decreasing interelectrode distance, Following epicardial stimulation, Laplacian amplitude was significantly larger than during complexes with different morphology. Collision of wavefronts was associated with entirely positive Laplacian waveforms; “focal” appearancce of acitivity was associated with an entirely negative waveform. Activation block in the activation maps was correlated with the appearance of substanined episodes of negativity or positivity in the Laplacian electrogram (depending on the location of the recording site relative to the line of block).Conclusion. Laplacian electrograms allow detection of the moment of local activation without interference from remote activity or repolarization, especially during complex arrhythmias. The technique applied toe automatic sensing devices, such its the internal defibrillator, may optimize defibrtilation success. (J Cardiovasc Electrophysiol, Vol. 11, pp. 1119‐1128, October 2000)
Effects of Electrode‐Myocardial Separation on Cardiac Stimulation in Conductive Solution
Authors: KNISLEY STEPHEN B. , POLLARD ANDREW E. , EAST VLADIMIR G. 
Published: April 2007

Electrode‐Myocardial Separation. Introduction. Effects of a conductive bath and electrodemyocardial separation on cardiac stimulation have not been elucidated. These factors may play a role in endocardial catheter stimulation or defibrillation.Methods and Results. We studied effects of a bath and separation on transmembrane voltage changes during stimulation (ΔVm) and excitation thresholds in rabbit hearts, cultured rat cardiac cell monolayers and cardiac bidomain computer models. Similar to previous epicardial measurements with no bath, a dogbone pattern of ΔVm during stimulation was found in bathed epicardium and right ventricular septal endocardium and in models of bathed anisotropic myocardium. Electrode‐myocardial separation altered spatial distributions of ΔVm, moved reversals of the sign of ΔVm farther from the stimulation epicenter, and decreased aspect ratio of ΔVm (i.e., length/width of dogbone contours of ΔVm). The separation increased thresholds and reduced maximal ΔVm, while ΔVm at sites away from maxima increased or decreased. Anodal thresholds in models initially were larger than those in experiments and decreased when models were altered to include nonuniform cellular coupling. Existence of nonuniformity in monolayers was indicated by irregular excitation patterns.Conclusion. Electrode‐myocardial separation alters spatial distributions of ΔVm, which may impact on arrhythmia induction by altering distributions of states of ΔVm‐sensitive ion channels. The results also indicate that excitation thresholds may depend on tissue nonuniformities. (J Cardiovasc Electrophysiol, Vol. 11. pp. 1132‐1143, October 2000)
Morphology of the Human Atrioventricular Node is Age Dependent: A Feature of Potential Clinical Significance
Authors: WAKI KENJI , KTM JUNG‐SUN , BECKER ANTON E. 
Published: April 2007

AVN Morphology Related to Age. Introduction. Advances in catheter ablation procedures have created the need to understand better the morphology of the AV node (AVN), particularly as it relates to age.Methods and Results. This study was based on 40 normally structured hearts obtained at autopsy from patients without a history of tachyarrhythmia in the following age ranges: <1 year (n = 19); 1‐12 years (n = 11); and 12‐20 years (n = 10). In 38 hearts, the AV septal junctional area was removed en bloc and serially sectioned at 10‐μm thickness at right angles to the AV annulus. The length of the compact node and the rightward and leftward inferlor extensions were calculated. Computer‐assisted three‐dimensional reconstructions were made of six hearts. The ratio of right extension to compact AVN showed a statistically significant increase with age; the increase in ratio of left extension to compact AVN was not statistically significant. In addition, with increasing age the geometry of the AVN changed from a half‐oval to a spindle shape, concomitant with development of a distinct so‐called muscular AV septum. The three‐dimensional reconstructions showed widening of the transitional cell zone with an increase in fibrofatty tissue related to age.Conclusion. The AVN, inferlor extensions, and transitional cell zone show distinet age‐related changes that may be clinically relevant. The increase in length of the inferior extensions may set the scene for AVN reentry and could explain why this condition is more frequent in young adults than in infants. (J Cardioyasc Electrophysiol, Vol. 11, pp. 1144‐1151. October 2000)
Nonfluoroscopic Three‐Dimensional Mapping for Arrhythmia Ablation: Tool or Toy?
Authors: KHONGPHATTHANAYOTHIN APICHAI , KOSAR EROL , NADEMANEE KOONLAWEE 
Published: April 2007

Arrhythmia Ahlation with Nonfluoroscopic 3D Mapping. Introduction: Conventional mapping and ablation rely on fluoroscopy, which can result in imprecise positioning of the ablation catheter and long fluoroscopic exposure times. We evaluated a nonfluoroscopic three‐dimensional mapping system, termed CARTO, and compared the results of ablation using this technique with those of conventional mapping.Methods and Results: We compared the results of 88 arrhythmia ablations (79 patients) using CARTO with 100 ablations (94 patients) using the conventional technique. The ablations were separated into four groups: (1) AV nodal reentrant tachycardia (AVNRT); (2) atrial tachycardia/flutter; (3) ventricular tacbycardia (VT); and (4) bypass tract tachycardia. We compared the success rate, complications, and fluoroscopy and procedure times. Tbe ablation outcomes were excellent and comparable in all four types of the arrhythmias between the two techniques. Major complications included one cardiac tamponade in each group and one second‐degree AV block in the conventional group. Fluoroscopy time was shorter using the CARTO technique: 10 ± 7 versus 27 ± 15 minutes for AVNRT (P < 0.01), 18 ± 17 versus 44 ± 23 minutes for atrial tachycardia and flutter (P < 0.01), 15 ± 12 versus 34 ± 31 minutes for VT (P < 0.05), and 21 ± 14 versus 53 ± 32 minutes for bypass tract tachycardia (P < 0.01). Procedure times were similar except for the bypass tract patients, wbich was shorter in the CARTO group, 4 ± 1.3 versus 5.5 ± 2.5 hours (P < 0.01).Conclusion: The electroanatomic three‐dimensional mapping technique reduced fluoroscopy time and resulted in excellent outcome without increasing the procedure time.
Role of Virtual Electrodes in Arrhythmogenesis: Pinwheel Experiment Revisited
Authors: LINDBLOM ANNETTE E. , ROTH BRADLEY J. , TRAYANOVA NATALIA A. 
Published: April 2007

Virtual Electrodes in Arrhythmogenesis. Introduction: Recent experimental evidence demonstrates that a point stimulus generates a nonuniform distribution of transmembrane potential (virtual electrode pattern) consisting of large adjacent areas of depolarization and hyperpolarization. This simulation study focuses on the role of virtual electrodes in reentry induction.Methods and Results: We simulated the electrical behavior of a sheet of myocardium using a two‐dimensional bidomain model with straight fibers. Membrane kinetics were represeuted by the Beeler‐Reuter Drouhard‐Roberge model. Simulations were conducted for equal and unequal anisotropy ratios. S1 wavefront was planar and propagated parallel or perpendicular to the fibers. S2 unipolar stimulus was catbodal or anodal. With regard to unequal anisotropy, for both cathodal and anodal stimuli, the S2 stimulus negatively polarizes some portion of membrane, deexciting it and opening an excitable pathway in a region of otherwise unexcitable tissue. Reentry is generated by break excitation of this tissue and subsequent propagation through deexcited and recovered areas of myocardium. Figure‐of‐eight and quatrefoil reentry are observed, with figure‐of‐eight most common. Figure‐of‐eight rotation is seen in the direction predicted by the critical point hypothesis. With regard to equal anisotropy, reentry was observed for cathodal stimuli only at strengths > ‐95 A/m.Conclusion: The key to reentry induction is the close proximity of S2‐induced excited and deexcited areas, with adjacent nonexcited areas available for propagation.
THE PUSH–PULL OF MARKETING AND ADVERTISING AND THE ALGEBRA OF THE CONSUMER'S MIND*
Authors: EWALD JEFF , MOSKOWITZ HOWARD 
Published: April 2007

ABSTRACT This article suggests that the relationship between a brand and a product is a virtuous circle—the brand frames expectations for a product execution; and the product experience either strengthens the brand perceptions or weakens them. Empirical evidence, based on a comprehensive database of scores collected across multiple conjoint studies, then confirms the hypothesis that different product attributes synergize, or interact, with different brand names.
MODELING CONSUMER INTENTION TO PURCHASE FRESH PRODUCE
Authors: DE SOUZA ELOIZA A.M. , MINIM VALÉRIA P.R. , MINIM LUIS A. , COIMBRA JANE S.R. , DA ROCHA RONEY A. 
Published: April 2007

ABSTRACT The effect of some fresh‐cut carrot label attributes on consumer purchase intention was evaluated using conjoint analysis. The following three attributes were chosen and manipulated: price (high and low), packaging type (polyethylene bags and expanded polystyrene trays) and production process (organic with certification stamp, organic without certification stamp and no information). A complete factorial design was used, and 12 hypothetical packages of fresh‐cut carrot were developed and evaluated by 96 consumers based on their purchase intention. The consumers were divided into four groups with different opinions. Low price and organic with certification label were the favorite choices of the groups. Only one group preferred expanded polystyrene trays. No interactions were exhibited among the attributes in all groups.
Delineating the “Ease of Doing Business” Construct within the Supplier–Customer Interface
Authors: Stading Gary , Altay Nezih 
Published: April 2007

SUMMARYThe current research provides insight into the “ease of doing business” construct. Factor analysis of survey responses of supply managers in the electronics industry was used to test the proposed “ease of doing business” construct, which includes the three dimensions — information and material services, financial contract services and personal relations services. Results support a link between a customer's assessment of a supplier's “ease of doing business” and the amount of business conducted with that supplier. The attributes supported by this research provide the means for managers to improve and grow business with customers.
The Working Postures Among Schoolchildren—A Controlled Intervention Study on the Effects of Newly Designed Workstations
Authors: Saarni Lea , Nygård Clas‐Håkan , Rimpelä Arja , Nummi Tapio , Kaukiainen Anneli 
Published: April 2007

ABSTRACTBackground:  School workstations are often inappropriate in not offering an optimal sitting posture. The aim of this study was to investigate the effects of individually adjustable saddle‐type chairs with wheels and desks with comfort curve and arm support on schoolchildren’s working postures compared to conventional workstations.Methods:  Ninety‐seven participants aged 12‐16 years were followed for 1 year, 47 at an intervention school and 50 at a control school. Anthropometrics and workstation dimensions were measured and working postures analyzed for a part of each group (n = 21, both groups) by means of video recording at baseline, before new workstations were introduced, and during follow‐up.Results:  There was a significant increase in upright back (p= .012) and neck (p= .019) postures in the intervention group compared to controls during follow‐up. The saddle‐type chairs allowed significantly greater trunk‐thigh angles (p < .001) among participants than conventional chairs.Conclusions:  In schoolchildren, using individually adjustable saddle‐type chairs and desks with comfort curve, a better match between workstations and anthropometric dimensions and improved working postures are obtained than using conventional workstations.
Chronic Pain in the Classroom: Teachers’ Attributions About the Causes of Chronic Pain*
Authors: Logan Deirdre E. , Catanese Sarah P. , Coakley Rachael M. , Scharff Lisa 
Published: April 2007

ABSTRACTBackground:  School absenteeism and other impairments in school function are significant problems among children with chronic pain syndromes; yet, little is known about how chronic pain is perceived in the school setting. The purpose of this study was to examine teachers’ attributions about the causes of chronic pain in adolescent students.Methods:  Classroom teachers (n = 260) read vignettes describing a hypothetical student with limb pain. They were presented with a list of possible physical and psychological causes for the pain and asked to identify the causes to which they attributed the pain. Vignettes varied by the presence or absence of (1) documented medical evidence for the pain and (2) communication from the medical team. Teachers also responded to questions assessing their responses to the student in terms of support for academic accommodations and sympathy for the student.Results:  Teachers tended to endorse a dualistic (ie, either physical or psychological) model for pain rather than a biopsychosocial model. Documented medical evidence supporting the pain was the most influential factor affecting teachers’ attributions about chronic pain. Teachers who attributed the pain to physical causes—either in isolation or in combination with psychological causes—responded more positively toward the student.Conclusions:  Many teachers lack a biopsychosocial framework through which to understand chronic pain syndromes in students. How chronic pain is described to school personnel may affect how teachers understand the pain and respond to it.
School Counselors and Student Self‐Injury
Authors: Roberts‐Dobie Susan , Donatelle Rebecca J. 
Published: April 2007

ABSTRACTBackground:  The purpose of this study was to examine the experience, knowledge, and needs of school counselors in relation to students’ self‐injurious behaviors.Methods:  One thousand members of the American School Counselor Association were randomly selected to receive a questionnaire on the study of self‐injury. Four hundred forty‐three school counselors returned usable questionnaires.Results:  Most (81%) reported working with a self‐injurer during their career, and 51% reported working with a self‐injurer during the 2002‐2003 school year. Findings suggest that counselors feel they are the appropriate person to work with students who self‐injure but need more training to identify self‐injurers and refer them to appropriate resources outside of the school. Counselors identified a number of barriers to successfully working with students who self‐injure, such as lack of training, lack of cooperation with school personnel, and lack of policy on school injury.Conclusions:  The authors suggest a model where the school counselor acts as a liaison to ensure the coordination of education about self‐injury for students, parents, and school staff and as a conduit to refer students to therapists in the community.
Legal Liability: The Consequences of School Injury
Authors: Barrios Lisa C. , Jones Sherry Everett , Gallagher Susan S. 
Published: April 2007

ABSTRACTBackground:  Approximately 10‐25% of child and adolescent injuries occur at school. Little is known about school‐related injuries to teachers and other adults or about the direct cost of injuries to schools. This study examined the characteristics of cases involving injuries resulting in lawsuits against schools, compared cases in which schools paid awards with those in which schools did not pay awards, and compared student and nonstudent injuries resulting in lawsuits against schools.Methods:  Descriptions of cases of school liability for personal injury that were tried or settled between July 1996 and May 2002 were purchased from Jury Verdict Research, which maintains a national database of verdicts and settlements. The 455 cases reviewed were coded according to the characteristics of the case, school, award, and injured party.Results:  In two thirds of the cases, schools or school districts paid an award to plaintiffs (mean =$562,915, median =$50,000). In most cases, the injured party was male (57.1%) and younger than 18 years of age (79.9%). Fractures (38.9%) were the most common type of injury. Falls (21.9%) were the most common cause of injury. Among cases of intentional injury, 93.2% involved an injury to a student; among cases of unintentional injury, 74.6% involved injury to a student.Conclusions:  Preventing school‐related injuries is an ethical and legal obligation for schools and school districts. Prevention is also critical because a wide range of injuries are litigated, and such lawsuits often require schools and school districts to pay costly awards to injured parties.
On Serrated Plastic Flow in an AA5052-H32 Sheet
Authors: Tong Wei , Zhang Nian 
Published: April 2007

Abstract
Temporal and spatial characteristics of serrated plastic flow or the so-called Portevin-Le Chatelier (PLC) deformation bands in a commercial Al-2.5%Mg sheet metal due to dynamic strain aging effects were investigated experimentally under quasi-static uniaxial tension. It was found that the thickness and width of test coupons, applied loading conditions (machine stiffness and crosshead speed), and mechanical polishing had an observable effect on the temporal characteristics of the serrated plastic flow while short and long interruptions during the tensile tests with stress relaxation and even completely unloading show minimal effects on the subsequent serrated flow behavior. Serrations in axial load in AA5052-H32 were found to associate with the appearance of discrete narrow deformation bands in the tensile test coupons with the bands aligned 59±1deg with respect to the tensile loading axis. The detailed strain distribution across the deformation bands showed a bell-like instead of steplike shape, indicating that the formation of these deformation bands was controlled by a local nucleation and growth process at a cross section in the polycrystalline sheet.