bluuebunny/crossref_metadata_2025_split huggingface dataset:
P Wave Signal‐Averaged Electrocardiography Techniques
Authors: Chan Eric K.Y. , Steinberg Jonathan S. , Santoni‐Rugiu Francesco , Gomes J. Anthony 
Published: September 2010

Background: P wave signal‐averaged electrocardiography (PW‐SAECG) is a new method that is proving to be an accurate and independent noninvasive marker for the risk of developing atrial fibrillation. This article presents current data acquisition and analysis techniques for PW‐SAECG. It also discusses in detail the interplay of inherent challenges present in the morphological attributes of the P wave, and how correct technique can play a large role in surmounting these challenges, thereby producing good results.Methods: Proper patient preparation and correct configuration of instrument settings ensure accurate P wave detection and alignment during the signal‐averaging process. This in turn preserves waveform integrity of the resulting signal‐averaged P wave data. Subsequent application of appropriate filtering schemes and signal processing methods permit the calculation and analysis of key PW‐SAECG time‐domain parameters.Conclusions: Judicious modification of established data acquisition protocols from R wave signal averaging, coupled with appropriate postprocessing and analysis techniques, are necessary precursors for arriving at acceptable time‐domain PW‐SAECG results.
P‐Wave Duration and Dispersion in Obese Subjects
Authors: Kosar Feridun , Aksoy Yüksel , Ari Fahri , Keskin Lezzan , Sahin Ibrahim 
Published: September 2010

Background: Although previous studies have documented a variety of electrocardiogram (ECG) abnormalities in obesity, P‐wave alterations, which represent an increased risk for atrial arrhythmia, have not been studied very well in these patients. The aim of the present study was to evaluate P‐wave duration and P dispersion (Pd) in obese subjects, and to investigate the relationship between P‐wave measurements, and the clinical and echocardiographic variables. Methods: The study population consisted of 52 obese and 30 normal weight control subjects. P‐wave duration and P‐wave dispersion were calculated on the 12‐lead ECG. As echocardiographic variables, left atrial diameter (LAD), left ventricular end‐diastolic, and end‐systolic diameters (LVDD and LVSD), left ventricular ejection fraction (LVEF), interventricular septum thickness (IVST), left ventricular posterior wall thickness (LVPWT), and left ventricular mass (LVM) of the obese and the control subjects were measured by means of transthoracic echocardiography. Results: There were statistically significant differences between obese and controls as regards to Pmax (maximum P‐wave duration) and Pd (P dispersion) (P < 0.001 and P < 0.001, respectively). Pmin (minimum P wave duration) was similar in both groups. Correlation analysis showed that Pd in the obese patients was related to any the clinical and echocardiographic parameters including BMI, LAD, LVDD, IVST, LVPWT, and LVM. Conclusion: Our data suggest that obesity affects P‐wave dispersion and duration, and changes in P dispersion may be closely related to the clinical and the echocardiographic parameters such as BMI, LAD, IVST, LVPWT, and LVM.
High Sensitivity CRP Levels Predict Atrial Tachyarrhythmias in Rheumatic Mitral Stenosis
Authors: Ucer Ekrem , Gungor Baris , Erdinler Izzet Celal , Akyol Ahmet , Alper Ahmet Taha , Eksik Abdurrahman , Cakmak Nazmiye , Gurkan Kadir , Ulufer Tanju 
Published: September 2010

Background: The different levels of inflammation in rheumatic mitral stenosis determine its clinical consequences. Atrial fibrillation is frequently encountered in mitral stenosis, though the independent role of chronic inflammation in determining atrial tachyarrhythmia occurrence in rheumatic heart disease has not been demonstrated previously. Methods: Measurements of C‐reactive protein (CRP) with a high sensitivity assay to detect chronic inflammation were performed in a homogenous group of 50 patients with rheumatic mitral stenosis, who were in sinus rhythm. Patients were questioned to exclude confounders of CRP elevation. The patients underwent a twenty‐four‐hour ambulatory ECG monitoring to check for asymptomatic atrial tachyarrhythmias and were in addition classified according to the presence of atrial tachyarrhythmias. Results: Forty‐four percent of patients showed a total of 100 episodes of atrial tachyarrhythmias where 63% of these episodes were paroxysmal atrial fibrillation. The CRP values in patients with tachyarrhythmias were significantly higher than in patients who remained in sinus rhythm (4.2 ± 0.55 mg/L vs 1.99 ± 0.36 mg/L, P < 0.001). A logistic regression analysis revealed only CRP levels and previous history of mitral valvuloplasty significantly determined tachyarrhythmia occurrence where age, left atrial volumes, mitral gradients had no statistically significant effect. Conclusions: Our data implicated that nearly half of the mitral stenosis patients who are in sinus rhythm develop asymptomatic tachyarrhythmias and the higher levels of CRP in these patients show the significant effect of persistent inflammation on arrhythmia occurrence.
Adenosine‐Induced Ventricular Arrhythmias in Patients with Supraventricular Tachycardias
Authors: Ertan Cagatay , Atar İlyas , Gulmez Oyku , Atar Asli , Ozgul Aliseydi , Aydinalp Alp , Müderrisoğlu Haldun , Özin Bülent 
Published: September 2010

Background: Adenosine is widely used for the diagnosis and the termination of supraventricular arrhythmias. There are many case reports and few series about the proarrhythmic potential of adenosine. We sought to evaluate the proarrhythmic potential of adenosine used to terminate the supraventricular arrhythmias. Methods: The records of all patients that received adenosine for the termination of supraventricular tachycardia were reviewed retrospectively and those with a continuous electrocardiographic (ECG) recording during adenosine administration were included to the study. Results: Our search identified 52 supraventricular episodes of 46 patients with a continuous ECG recording during adenosine administration. Following adenosine administration, premature ventricular contraction (PVC) or ventricular tachycardia (VT) developed in 22 (47.8%) patients and in 26 (50%) tachycardia episodes. No patient had a sustained VT. Nonsustained VT developed in eight (17.4%) patients. All VT episodes were polymorphic, short, and self‐terminating. When the basal and demographic properties of patients with PVC or VT and those without PVT or VT were compared, there was no significant difference. Conclusions: Adenosine is a quite safe and effective drug for the termination of narrow QRS complex tachycardia but it often induces nonsustained VT or PVC that are clinically insignificant in the absence of other accompanying heart disease.
Correlation of Modification of Heart Rate Recovery with Adaptation to Myocardial Ischemia in a Model of Sequential Exercise Testings
Authors: Michaelides Andreas P. , Fourlas Christos A. , Andrikopoulos George K. , Antoniades Charalambos , Soulis Dimitrios , Chatzistamatiou Evangelos , Stefanadis Christodoulos I. 
Published: September 2010

Background: Heart rate recovery (HRR) has been identified as a reliable predictor of cardiac mortality, correlated with autonomic tone. In a model of sequential exercise testings, we investigated the reproducibility of HRR and the association between HRR modification and myocardial adaptation to ischemia. Methods: We studied 128 patients (mean age 62 ± 9 years, 83% males) with angiographically documented coronary artery disease (CAD) and a first positive exercise testing, who agreed to undergo a second exercise testing after 24 hours. Results: HRR was increased from 25 ± 10 beats/min at the first exercise testing to 30 ± 13 beats/min at the second exercise testing (P < 0.001). Thereafter, participants were divided into two groups: Group I comprised 88 patients who presented augmentation of the HRR in the first compared to the second exercise testing, while group II comprised 40 patients who presented unchanged or reduced HRR. The rate‐pressure product (RPP) at 1 mm ST‐segment depression (ischemic threshold) at the second compared to the first exercise testing were significantly improved in group I patients (2345 ± 3429 mmHg/min), while it was worsened in group II patients (−630 ± 2510 mmHg/min) (P < 0.001). Conclusions: In a model of sequential exercise testings, myocardial adaptation to exercise‐induced ischemia was associated with favorable modification of HRR.
Study of the Extent of the Information of Cardiologists from São Paulo City, Brazil, Regarding a Low‐Prevalence Entity: Brugada Syndrome
Authors: Pérez Riera Andrés Ricardo , Filho Celso F. , Uchida Augusto H. , Zhang Li , Antzelevitch Charles , Schapachnik Edgardo , Dubner Sergio , Ferreira Celso 
Published: September 2010

Objective: To determine the degree of knowledge that cardiologists from São Paulo, Brazil, have regarding a low‐prevalent entity associated with a high rate of sudden death—Brugada syndrome. Methods: Two hundred forty‐four cardiologists were interviewed by an instrument divided in two parts: in the first, we recorded gender, age, and data related to academic profile. The second—answered only by the professionals that manifested having some degree of knowledge on the syndrome—had 28 questions that evaluated their knowledge. The answers were spontaneous and they did not have a chance to consult. We used uni‐ and multivariate analysis on the average percentage of right and wrong answers, and the influence of the academic profile. Results: The predominant gender was the male gender (61.1%), the average age was 44.32 ± 10.83 years, 40% with more than 20 years after obtaining their degree, 44% were educated in public institutions, 69% had a residency in cardiology, 20% had overseas practice, 12% had postdegree, 41% were linked to an educational institution, 24% with publication(s) in an indexed journal, 17.2% were authors of chapters in books, 2.5% had edited books, and 10% were linked to the Brazilian Society of Cardiac Arrhythmias. The average percentage of right answers was 45.7%. Conclusion: The sample studied revealed a little knowledge on the entity. A residency in cardiology was the factor of greater significance in the percentage of right answers. Other significant factors were the link of the interviewed person to an educational institution, or the Brazilian Society of Cardiac Arrhythmias, and having a specialist degree.
Long QT Syndrome in Patients over 40 Years of Age: Increased Risk for LQTS‐Related Cardiac Events in Patients with Coronary Disease
Authors: Sze Edward , Moss Arthur J. , Goldenberg Ilan , McNitt Scott , Jons Christian , Zareba Wojciech , Qi Ming , Robinson Jennifer L. ,   for the International Long QT Syndrome Investigative Group
Published: September 2010

Background:Previous studies of long QT syndrome (LQTS) have focused primarily on the clinical course of affected patients up to 40 years of age to avoid the confounding influence of acquired heart disease on LQTS‐related cardiac events in this genetic disorder.Methods:Patients were identified as having coronary disease if they had a history of hospitalization for myocardial infarction, coronary angioplasty, coronary artery bypass graft surgery, or were treated with medication for angina. LQTS‐related cardiac events included the first occurrence of syncope, aborted cardiac arrest, or sudden cardiac death without evidence suggestive of an acute coronary event. Cox proportional hazards regression modeling was used to analyze the independent contribution of coronary disease to LQTS‐related cardiac events.Results:Time‐dependent coronary disease was associated with an increased risk of LQTS‐related cardiac events (hazard ratio 2.24, 95% confidence interval 1.23–4.07, P = 0.008) after adjustment for syncopal history before age 40, QTc, and gender. Factors such as diabetes and hypertension that increase the risk for coronary disease were not associated with an increased risk for LQTS‐related cardiac events.Conclusions:This is the first study to demonstrate that coronary disease augments the risk for LQTS‐related cardiac events in LQTS. The findings highlight the need for more focused preventive therapy in LQTS patients above the age of 40.
High‐Resolution Signal‐Averaged Analysis of Atrial Electromagnetic Characteristics in Patients with Paroxysmal Lone Atrial Fibrillation
Authors: Jurkko Raija , Väänänen Heikki , Mäntynen Ville , Kuusisto Jouni , Mäkijärvi Markku , Toivonen Lauri 
Published: September 2010

Background: Abnormalities in the electromagnetic signal of the atria during sinus rhythm could serve as markers of triggering foci or substrate for atrial fibrillation (AF). We examined atrial electrophysiologic properties noninvasively by using magnetocardiographic mapping (MCG) in patients with paroxysmal lone AF to find whether any difference exists between those who have frequent triggers of AF and who don't. Methods: MCG was recorded over anterior chest during sinus rhythm in 80 patients with paroxysmal lone AF (44 ± 12 years, 61 males) and 80 matched controls. Atrial wave duration (Pd) and root mean square amplitudes of the last 40 ms (RMS40) of the averaged filtered atrial complex were determined automatically. Patients expressing atrial arrhythmias triggering AF episodes were classified as focal AF. Results: The Pd was 109 ms in patients and 104 ms in controls (P = 0.007). In focal AF (72%) the Pd was slightly prolonged and its proportion of the PR interval was larger, but RMS40 was normal compared to controls. In other patients, the Pd was close to controls, but the RMS40 was reduced (59 ± 17 vs74 ± 36 fT, P = 0.006). Pd and atrial RMS amplitudes were unrelated to duration of AF history or frequency of recurrences. Conclusion: Clinical subclasses of lone AF seem to possess distinct signal profiles of atrial depolarization. Differences in electrophysiological properties between these subclasses may reflect pathogenetic variation and could have implications on diagnostics and therapy.
The Artist and the City in “Euro‐Mediterranean” Marseille: Redefining State Cultural Policy in an Era of Transnational Governance
Authors: INGRAM MARK 
Published: September 2010

AbstractFocused on an arts center in Marseille, this article explores how globalization and Europeanization are affecting relations between local cultural producers, national culture, and the state. In France, the state's claims to reshape civil society through cultural policy have been challenged by critics who conclude that economic priorities have ended an era of civic‐centered state arts policy. At the same time, local authorities in the Provence‐Alpes‐Côtes d'Azur region value “new territories of art” projects as initiatives consonant with Euro‐Mediterranean commerce and exchange. Adapting to this context, these artists both challenge and rearticulate state cultural policy. They pursue the same universalist Republican ideals of earlier state policy but they re‐define them for the distinctively Mediterranean setting of Marseille. Thus, in spite of anti‐state discourse by artists, and fears that the public nature of their work has been compromised by economic liberalization, this case shows the ongoing power of the state to shape cultural policy discourse at the same time that it shows artists interpreting the terms of this discourse in ways that are dynamic, locally‐distinctive, and transnational.
Direct Associations or Internal Transformations? Exploring the Mechanisms Underlying Sequential Learning Behavior
Authors: Gureckis Todd M. , Love Bradley C. 
Published: September 2010

AbstractWe evaluate two broad classes of cognitive mechanisms that might support the learning of sequential patterns. According to the first, learning is based on the gradual accumulation of direct associations between events based on simple conditioning principles. The other view describes learning as the process of inducing the transformational structure that defines the material. Each of these learning mechanisms predicts differences in the rate of acquisition for differently organized sequences. Across a set of empirical studies, we compare the predictions of each class of model with the behavior of human subjects. We find that learning mechanisms based on transformations of an internal state, such as recurrent network architectures (e.g., Elman, 1990), have difficulty accounting for the pattern of human results relative to a simpler (but more limited) learning mechanism based on learning direct associations. Our results suggest new constraints on the cognitive mechanisms supporting sequential learning behavior.
Does Playing Blindfold Chess Reduce the Quality of Game: Comments on Chabris and Hearst (2003)
Authors: Jeremic Veljko , Vukmirovic Dragan , Radojicic Zoran 
Published: September 2010

AbstractBlindfold chess is a special type of chess game where both the board and pieces are not visible to its players. This paper aims to determine whether the quality of the game played blindfolded is lower than when played under normal conditions. The best chess program was used to analyze games played by the world's top Grandmasters under both conditions. We have analyzed the Monaco 1993–1998 data set introduced by Chabris and Hearst (2003). The results showed that although a larger number of mistakes occurred while playing blindfolded, no significant statistical difference between the rapid and blindfold games has been found. Nevertheless, by applying the same methodology to the Monaco 2002–2007 data set a substantial difference between the blindfold and the rapid chess game was noticed. In this paper, we have addressed the possible improvement of the chess game quality and the advances in chess programs that may be responsible for detecting more blunders.
A multi‐Gaussian model for predicting crawler occurrence of Unaspis yanonensis in citrus orchards
Authors: Kim Dong‐Soon , Choi Kyung‐San , Lee Joon‐Hak 
Published: September 2010

AbstractArrowhead scale, Unaspis yanonensis (Kuwana) (Hemiptera: Diaspididae), feeds on the foliage, stems, and fruits of citrus trees and causes tree dieback when heavy infestations occur. Multi‐Gaussian models (three‐ and two‐peak models) were developed for better management of the arrowhead scale in citrus orchards and later validated against several field data sets. The oviposition activities observed in the laboratory were highly correlated with both models (r2 = 0.88). The three peak oviposition times estimated by the three‐peak model were at 282, 500, and 694 degree‐days, based on a low threshold temperature of 13 °C. Also, the peak oviposition times of the two‐peak model were identical to the first and second peak times of the three‐peak model. Both models accurately predicted the first oviposition peak period of field populations. In the later peak period, both model outputs well predicted the actual crawler populations, except for the tail end of actual peak periods which were underestimated in the two‐peak model and overestimated in the three‐peak model. Overall, both models showed a strong robustness for correlation with actual data. The newly developed multi‐Gaussian models better described the actual population phenology of U. yanonensis than the previously published models, and either model would be useful for the management of U. yanonensis in the field.
The bone–metal interface of defect and press‐fit ingrowth of microwave plasma‐chemical vapor deposition implants in the rabbit model
Authors: Rupprecht Stephan , Bloch‐Birkholz Alexandra , Lethaus Bernd , Rosiwal Stefan , Neukam Friedrich Wilhelm , Schlegel Andreas 
Published: September 2010

AbstractPurpose: The histological differences between the defect and contact areas of the implant surface to bone were tested in 35 New Zealand White rabbits in a standardized model. Microwave plasma chemical vapor‐coated implant probes were tested in control and uncoated materials.Material and methods:  In each femur of 35 rabbits, cylindrical implant rods with a planed side were inserted. Three groups, divided in coated and uncoated material at half, were observed 42, 84 and 168 days. The probes were examined histologically for bone–implant contact in the curved and plane (defect area) sides.Results: Generally the bone–implant contact seems to be nearly constant in time in the curved area of coated and uncoated probes. Here the implant was inserted in the press‐fit mode. Diamond‐coated probes showed similar bone–implant contact (51.9% (42 days), 62.5% (84 days), 56.1% (168 days)) compared to uncoated material (56.2%, 65.4%, 62.9%). The defect area (plane side) had no bone–implant contact at the time of insertion and showed increasing values on longer observation times with only significant differences in the 42‐day group between coated (17.85%, 35.2%, 47.7%) and uncoated materials (35.5%, 40.55%, 51.81%).Conclusion: The evaluation of the curved side of the implant probe showed no great variation of bone–implant contact within the described observation times. This model simulates the usual implant insertion situation. The diamond‐coated material becomes osseointegrated at a later time point. The bone–implant contact was only statistically relevant in one group in comparison to uncoated material.
Mandibular overdentures supported by two or four endosseous implants
Authors: Visser Anita , Raghoebar Gerry M. , Meijer Henny J. A. , Batenburg Rutger H. K. , Vissink Arjan 
Published: September 2010

AbstractObjective: The aim of this 5‐year prospective comparative study was to evaluate treatment outcome (survival rate, condition of hard and soft peri‐implant tissues, patient satisfaction, prosthetic and surgical aftercare) of mandibular overdentures supported by two or four implants.Material and methods: Sixty edentulous patients with a mandibular height between 12 and 18 mm participated. Thirty patients were treated with an overdenture supported by two IMZ implants (group A) and 30 patients were treated with an overdenture supported by four IMZ implants (group B). Standardised clinical and radiographic parameters were evaluated 6 weeks after completion of the prosthetic treatment and after 1, 2, 3, 4 and 5 years of functional loading. Prosthetic and surgical aftercare was scored during the evaluation period.Results: One implant was lost (group A) during the healing period. There were no significant differences with regard to any of the studied clinical or radiographic parameters of the peri‐implant tissues between the groups. None of the patients reported sensory disturbances in the lip or chin region. No differences in satisfaction were observed between the groups. With regard to aftercare, there was a tendency of a greater need of prosthetic interventions in group A, while correction of soft‐tissue problems was restricted to patients of group B.Conclusion: There is no difference in clinical and radiographical state of patients treated with an overdenture on two or four implants during a 5‐year evaluation period. Patients of both groups were as satisfied with their overdentures.