bluuebunny/crossref_metadata_2025_split huggingface dataset:
Usefulness of Holter Recordings in the Evaluation of Pacemaker Function: Standard Techniques and Intracardiac Recordings
Authors: Barold S. Serge 
Published: October 2006

A dedicated pacemaker Holter system facilitates recognition of the pacemaker stimulus by amplifying and displaying it in an ECG channel without any other data. Such a Holter pacemaker channel may occasionally generate electrostatic charges that produce deflections resembling pacemaker stimuli (pseudopacemaker spikes) arising from a loose ECG electrode, crushed tape, or a dirty recording head. False‐positive spikes or spurious marker deflections in Holter pacemaker channels and occasional failure to detect tiny bipolar stimuli can present challenging problems in the interpretation of pacemaker function. In multiple‐channel recorders, skewing of the recording heads may lead to timing errors and puzzling recordings when one of the ECG or pacemaker channels lags behind others producing asynchrony or malalignment in simultaneously recorded tracings.The interpretation of Holter recordings from contemporary complex pacemakers requires knowledge of pacemaker timing cycles and their interrelationships, a large variety of programmable parameters or functions, behavior of the nonatrial sensor or sensors in rate‐adaptive systems, device‐specific responses to protect the system from a variety of undesirable situations, and an appreciation of pacemaker eccentricities.There are a few prospective studies on the value of routine Holter recordings in pacemaker patients. The real value of Holter recordings lies with symptomatic patients when symptoms occur during the recording period. Correlation between symptoms and occasional abnormality of pacemaker function during Holter monitoring remains poorly characterized. The cause of the symptoms is frequently unrelated to the pacemaker system and may not be related to coexisting arrhythmias. In asymptomatic patients, Holter recordings are particularly useful to uncover a lead problem after an unrevealing thorough investigation in the pacemaker clinic.Special instrumentation was recently developed to register telemetry data from implanted pacemakers simultaneously with ambulatory electrocardiography. In this way, diagnostic marker signals and/or intracardiac electrograms transmitted from the pacemaker can be recorded continuously for 24 hours by a Holter recorder. Advanced technology involving the memory capability of pacemakers will transform the pacemaker itself into a 24‐hour Holter recorder, probably in 4 to 5 years. At present, the memory for storage of intracardiac electrograms is limited from a few seconds to less than a minute according to the manufacturer, but even such mini‐Holter recordings can be diagnostically important.
QT Measurement: A Comparison of Three Simple Methods
Authors: Tran Hieu T. , Fan Chengde , Tu Wei Q. , Kertland Heather , Li Li , Kluger Jeffrey , Chow Moses S.S. 
Published: October 2006

Background: QT interval and QT dispersion are useful noninvasive measurements in clinical cardiology and can be measured by several methods. The comparative variability of these methods, however, is not well defined.Methods: We evaluated the intra‐ and interobserver variability of three simple methods of QT measurement: (1) ruler method: use of a 0.5‐mm scale precision ruler to measure QT with end of T wave determined by extrapolating its slope to baseline; (2) caliper method: use of a standard electrocardiogram (ECG) caliper and the standard ECG paper scale with QT determined by visual inspection; (3) computer method: use of a digitized computer software program with QT determined by cursor set manually by the user. QT intervals from 11 patients (total 44 ECG leads) in sinus rhythm without conduction defect were measured by five blinded, trained observers at two time points (a week apart) in a crossover manner.Results: The mean difference in intraobserver measurements were 6 ± 2, 12 ± 12, and 27 ± 2 ms by the ruler, caliper, and computer methods, respectively (P > 0.01, ruler vs caliper or computer). The mean differences in interobserver measurements were 13 ± 3, 16 ± 4, and 29 ± 3 ms for the same methods, respectively (P > 0.01, ruler vs caliper, computer). Enlargement of the ECG to 200% did not reduce the measurement variability.Conclusion: The ruler method as described yielded the lowest variability in QT measurement.
Significance of the Accuracy of RR Interval Detection for the Analysis of New Dynamic Measures of Heart Rate Variability
Authors: Tapanainen Jari M. , Seppänen Tapio , Laukkanen Raija , Loimaala Antti , Huikuri Heikki V. 
Published: October 2006

Background: Interest in the analysis of RR interval variability by new dynamic methods is growing, because these methods give different, complementary information on heart rate behavior compared to the traditional measures of HRV. Several new methods have been recently introduced for studying complex heart rate dynamics, but the validity of these methods in analyzing RR interval behavior from Holter recordings is not well established.Methods: A real‐time microprocessor QRS detector system using a 1‐ms timing accuracy and a conventional 24‐hour ECG recording system with a sampling frequency of 128 Hz were compared in the measurement of new dynamic components of HRV in a sample of ten healthy subjects and ten patients with acute Ml.Results: Significant errors were observed in the analysis of approximate entropy (ApEn; mean difference 11 %) and in the short‐term scaling exponent value a1 (mean difference 3%) in detrended fluctuation analysis (DFA). In the Poincaré analysis, notable differences were also observed in short‐term instantaneous RR‐interval variability (SD1; mean difference 5%). In spectral analysis, low‐to‐high frequency ratio was also influenced by the sampling frequency (mean difference 14%). The magnitude of all these differences grew proportionately when the overall heart HRV diminished.Conclusions: The data suggest that conventional Holter recordings should be used with caution in the analysis of new dynamic HRV parameters, especially approximate entropy and the ratio between low and high frequency spectral components, particularly in patient populations with low total HRV.
The Effect of Left Ventricular Function on QT Dispersion in Postmyocardial Infarction Patients with Previous Ventricular Tachyarrhythmias
Authors: Kluger Jeffrey , Giedrimiene Dalia , White C. Michael 
Published: October 2006

Objectives: To determine if the presence of left ventricular dysfunction increases the QT and QTc dispersion in postmyocardial infarction patients with ventricular tachyarrhythmias and to determine if left ventricular infarct location is associated with differences in QT and QTc dispersion.Methods: The data was gathered from a retrospective electrophysiology (EP) database. All postinfarction patients (n = 87) with a past medical history of left ventricular myocardial infarction and ventricular tachyarrhythmia at baseline without bundle branch block or other intraventricular conduction abnormality were included. Patients were separated into those with an LVEF < 40% or < 40%. For secondary analysis, patients were separated into groups based on the location of the infarction. The QT and R‐R intervals were determined from each lead of a 12‐lead electrocardiogram (ECG) taken during the baseline EP study. The shortest QT and QTc intervals were subtracted from the longest intervals on the 12‐lead ECG to give the QT and QTc dispersions.Results: The QT and QTc interval dispersions were significantly greater among patients with an LVEF < 40% than among those with an LVEF < 40% (57.3 ± 28.2 vs 47.4 ± 17.7, P = 0.05; 64.5 ± 32.1 vs 48.8 ± 18.2. P = 0.005, respectively). No differences in QT or QTc dispersion were noted between patients with anterior or inferior myocardial infarctions.Conclusions: A higher QT dispersion can be predicted in patients with left ventricular dysfunction, but the location of the myocardial infarction does not predict the QT dispersion.
Variability in the Manifestation of Pre‐excited Atrial Fibrillation: Its Quantification, Theoretical Origin, and Diagnostic Potential
Authors: Lau Ernest W. , Ng G. André , Griffith Michael J. 
Published: October 2006

Background: Irregular broad complex tachycardia (BCT) may be due to atrial fibrillation (AF) occurring in the presence of ventricular pre‐excitation (pre‐excited AF) or bundle branch block (BBB‐AF). While irregularity is a defining characteristic of AF. it is a common subjective impression that greater variability in manifestation exists for pre‐excited AF than BBB‐AF. This difference can potentially be exploited for distinguishing the two conditions it some means can be found to quantify it.Methods: For each of 75 ECGs showing irregular BCT (41 pre‐excited AF and 34 BBB‐AF), a random sample of 10 distinct QRS complexes were selected for quantitative measurement of variability in manifestation, which included the standard deviation (SD) of the width, the SD of the axis, and the coefficient of variation (CV) of the amplitude of the QRS complex.Results: Pre‐excited AF showed statistically significantly greater values than BBB‐AF with respect to these measures, and receiver‐operating characteristic curves showed that these differences could be useful for their discrimination. For the SD of QRS width, a cut‐off value of 8 ms appeared optimal (sensitivity 1.00 and specificity 0.79). For the SD of QRS axis, a cut‐off value of 2.5 degrees appeared optimal (sensitivity 0.84 and specificity 0.56). For the CV of QRS amplitude, a cut‐off value of 0.10 appeared optimal (sensitivity 0.82 and specificity 0.76).Conclusions: Pre‐excited AF demonstrated greater variability than BBB‐AF in manifestation. The measures of variability developed can potentially be useful for diagnosing irregular BCT in practice, especially in the context of automated computer‐aided diagnosis. A.N.E. 2001;6(2):117–122
An Evaluation of the Impact of Gender and Age on QT Dispersion in Healthy Subjects
Authors: Tran Hieu , White C. Michael , Chow Moses S.S. , Kluger Jeffrey 
Published: October 2006

Objectives: To determine if gender, age, and gender per age category, have an impact on QT and QTc dispersion in healthy volunteers.Methods: This study was undertaken in 150 patients (50 per age group, 75 males, 75 females). The age groups included young (20–40 years), middle‐aged (41–69 years) and elderly (> 70 years) subjects. The QT intervals on a 12 lead ECG were determined and Bazett's formula was used to derive the QTc intervals. The QT and QTc dispersion were determined by subtracting the shortest QTc interval from the longest on each 12‐lead recording.Results: Males had higher QT dispersion than females (50 ± 22 vs 42 ± 18 ms, P = 0.017) but QTc dispersion was not significantly changed. No significant differences were seen among the different age categories for QT or QTc dispersion. In elderly subjects, males had higher QT and QTc dispersion than females (54 ± 23 vs 42 ±15 ms, P = 0.039 and 63 ± 23.7 vs 48 ± 21 ms, P = 0.032, respectively).Conclusions: When evaluating the effect of gender in different age categories, elderly males have significantly greater QT and QTc dispersion than elderly female subjects. No other gender differences were noted for QT or QTc dispersion in the other two age categories. When evaluating a population of healthy volunteers, regardless of age, gender has an impact on QT dispersion but no significant interaction with QTc dispersion. Evaluating age without dividing the data by gender yields no significant differences in QT or QTc dispersion. A.N.E. 2001;6(2):129–133
P‐Wave Signal‐Averaged Electrocardiogram Predicts Atrial Fibrillation After Coronary Artery Bypass Grafting
Authors: Caravelli Paolo , De Carlo Marco , Musumeci Giuseppe , Tartarini Giuseppe , Gherarducci Gherardo , Bortolotti Uberto , Mariani Massimo A. , Mario Mariani And 
Published: October 2006

Background: AF is one of the most common complications after CABG. The aim of the study was to identify the risk factors for postoperative AF.Methods: Between June and December 2000, 129 consecutive patients (72 men, 47 women; mean age 67 ± 6 years) underwent preoperative signal‐averaged electrocardiogram (SAECG) with assessment of filtered P‐wave duration (fPWD) and of the root mean square voltage of the last 10 and 20 ms of atrial depolarization (RMSV10 and RMSV20, respectively) before CABG.Results: Fifty‐six (43%) patients developed one episode of AF lasting > 30 seconds at a mean distance of 2.6 ± 1.8 days after surgery (group A), while 73 patients remained in sinus rhythm (group B). No differences between the two groups were found in terms of age, sex, P‐wave duration on the standard ECG, left atrial dimensions, and operative characteristics. In contrast, group A patients showed a significantly longer fPWD (138 ± 10 vs 111 ± 9 ms; P < 0.001) and smaller RMSV10 and RMSV20 (2.8 ± 1.0 vs 4.3 ± 1.1 μV, P < 0.001; 4.2 ± 2.1 vs 6.2 ± 2.0 μV, P < 0.001). Multivariate analysis indicated only fPWD as an independent predictor of AF (P = 0.009). With a cut‐off value of 135 ms for fPWD, the occurrence of AF could be predicted with a sensitivity of 84%, a specificity of 73%, a negative predictive value of 85%, and a positive predictive value of 70%.Conclusion: Preoperative SAECG is a simple exam that correctly identifies patients at higher risk of AF after CABG. A more widespread use of this technique can be suggested. A.N.E. 2002;7(3):198–203
Cardiovascular Autonomic Function in Conscious Rats: A Novel Approach to Facilitate Stationary Conditions
Authors: Ramaekers Dirk , Beckers Frank , Demeulemeester Hilde , Aubert André E. 
Published: October 2006

Background An experimental setting and software were developed to evaluate cardiovascular autonomic function in conscious rats. A restrained approach was used, which, upon proper habituation, induced little or no stress in the rats and limited motion artifacts.Methods: The ECG and arterial blood pressure were recorded. Time‐ and frequency‐domain indices of heart rate variability (HRV) and blood pressure variability (BPV) were calculated. The spontaneous baroreflex sensitivity (spBRS) was estimated using the method of statistical dependence.Results: The power spectra clearly concentrated in a frequency band with center frequency around 0.4 Hz, the low frequency (LF) component, and one at the respiratory frequency at 1.5 Hz, the high frequency (HF) component. In baseline conditions, a direct association existed between mean R‐R and especially HRV parameters denoting vagal modulation such as rMSSD, pNN5, and HF power. Beta‐adrenergic blockade by propranolol diminished basal heart rate. Vagal indices increased while there was an exclusive decrease in the low frequency band of HRV. Alpha‐adrenergic blockade with phentolamine produced a depressor response with tachycardia, and a clear decrease in the LF component of BPV. Both the LF and HF component in the HRV spectrum were virtually absent. Cholinergic blockade with atropine did not significantly alter BP but induced a clear tachycardia with decreased vagal indices. The HF component of HRV was completely abolished and the LF band was reduced.Conclusions: Both a‐ and 13‐adrenergic blockade left 5pBRS virtually unaltered, while cholinergic blockade profoundly diminished spBRS. Spectral fluctuations of 13‐sympathetic tone were restricted to the LF range of HRV, while the HF respiratory component represented vagal modulation. The a‐sympathetic system played a dominant role in the LF oscillations of BPV. A role of the vagus in the HF oscillations of BPV in the rat is questioned. The baroreflex depended mainly on changes in vagal activity. A.N.E. 2002;7(4):307–318
The first stars in the Universe
Authors: Naoz S. , Noter S. , Barkana R. 
Published: October 2006

Abstract
Large telescopes have allowed astronomers to observe galaxies that formed as early as 850 million years after the big bang. We predict when the first star that astronomers can observe (i.e. in our past light cone) formed in the Universe, accounting for the first time for the size of the Universe and for three essential ingredients: the light travel-time from distant galaxies, Poisson and density fluctuations on all scales, and the effect of very early cosmic history on galaxy formation. We find that the first observable star is most likely to have formed 30 million years after the big bang (at redshift 65). Also, the first galaxy as massive as our own Milky Way likely formed when the Universe was only 400 Myr old (at redshift 11). We also show that significant modifications are required in current methods of numerically simulating the formation of galaxies at redshift 20 and above.
From Exotics to Brainwashers: Portraying New Religions in Mass Media
Authors: McCloud Sean 
Published: October 2006

AbstractThis essay examines how American magazines have portrayed new religions since the World War II. Media depictions have changed dramatically from the 1950s to the present. Specifically, journalists in the 1950s and early 1960s used the dual Cold War themes of exoticism and subversion to depict new religions. In the late 1960s and early 1970s, subjects and themes began to change. Newsmagazines ambivalently reported on the gurus, Asian new religions, and occult spirituality attracting some in the burgeoning youth counterculture with a mixture of exoticism and wariness. By the mid‐1970s, media images became more ominous. News, general interest, and entertainment media represented new religions as a growing “cult menace” and highlighted the dangers that brainwashing groups posed to unsuspecting followers. The 1978 Jonestown mass suicide seemed to confirm such negative cult stereotypes, leading to homogenous portrayals of new religions that continued through the 1990s. In explaining such changes over time, the essay ends by proposing five complimentary theses for understanding late‐twentieth‐century mass media representations of new religions.
Jews and Judaism in Dixie
Authors: Bauman Mark K. 
Published: October 2006

AbstractThis article advocates the integration of Southern Jewish history into the mainstream study of Southern and American history and religion. It argues that such integration provides greater breadth and depth to those fields as well as a fruitful model for comparison and contrast. This article also provides reference to some of the necessary resources to scholars in other fields and brings the readers’ attention especially to a new publication for that purpose: Dixie Diaspora: An Anthology of Southern Jewish History.
Epithelial cyst of the cardiac papillary muscle: case report and review of the literature: Figure 1
Authors: Soilleux E J , Davies D R 
Published: October 2006

Background:Reports of endodermal heterotopia (previously known as inclusion cysts) in cardiac atria are rare and there is only a single previous case report of endodermal heterotopia in a cardiac papillary muscle.Aim and methods:A cyst in a cardiac papillary muscle was identified during the autopsy of an 87-year-old man who had died from an unrelated myocardial infarction. The cyst was examined histologically and mucin staining and immunostaining were carried out.Results:We report a unilocular cyst in a cardiac papillary muscle, which is lined by low cuboidal, pseudostratified and occasionally ciliated respiratory-type epithelium, surrounded by a layer of smooth muscle. The immunohistochemical features (MNF116+, cytokeratin (CK)7+, CK8+, CK18+, CK19+, epithelial membrane antigen positive, scattered cells positive for neuroendocrine markers) suggest that this is an endodermal heterotopia. Immunostaining of positive thyroid transcription factor-1 provides evidence for bronchogenic differentiation.Discussion:The differential diagnoses of cystic structures in cardiac papillary muscle and the origin and importance of endodermal heterotopias are discussed.
Hierarchical and Linear Sequence Processing: An Electrophysiological Exploration of Two Different Grammar Types
Authors: Bahlmann Jörg , Gunter Thomas C. , Friederici Angela D. 
Published: October 2006

Abstract
The present study investigated the processing of two types of artificial grammars by means of event-related brain potentials. Two categories of meaningless CV syllables were applied in each grammar type. The two grammars differed with regard to the type of the underlying rule. The finite-state grammar (FSG) followed the rule (AB) n , thereby generating local transitions between As and Bs (e.g., n = 2, ABAB). The phrase structure grammar (PSG) followed the rule A n B n , thereby generating center-embedded structures in which the first A and the last B embed the middle elements (e.g., n = 2, [A[AB]B]). Two sequence lengths (n = 2, n = 4) were used. Violations of the structures were introduced at different positions of the syllable sequences. Early violations were situated at the beginning of a sequence, and late violations were placed at the end of a sequence. A posteriorly distributed early negativity elicited by violations was present only in FSG. This effect was interpreted as the possible reflection of a violated local expectancy. Moreover, both grammar-type violations elicited a late positivity. This positivity varied as a function of the violation position in PSG, but not in FSG. These findings suggest that the late positivity could reflect difficulty of integration in PSG sequences.
Neural Bases of Motivated Reasoning: An fMRI Study of Emotional Constraints on Partisan Political Judgment in the 2004 U.S. Presidential Election
Authors: Westen Drew , Blagov Pavel S. , Harenski Keith , Kilts Clint , Hamann Stephan 
Published: October 2006

Abstract
Research on political judgment and decision-making has converged with decades of research in clinical and social psychology suggesting the ubiquity of emotion-biased motivated reasoning. Motivated reasoning is a form of implicit emotion regulation in which the brain converges on judgments that minimize negative and maximize positive affect states associated with threat to or attainment of motives. To what extent motivated reasoning engages neural circuits involved in “cold” reasoning and conscious emotion regulation (e.g., suppression) is, however, unknown. We used functional neuroimaging to study the neural responses of 30 committed partisans during the U.S. Presidential election of 2004. We presented subjects with reasoning tasks involving judgments about information threatening to their own candidate, the opposing candidate, or neutral control targets. Motivated reasoning was associated with activations of the ventromedial prefrontal cortex, anterior cingulate cortex, posterior cingulate cortex, insular cortex, and lateral orbital cortex. As predicted, motivated reasoning was not associated with neural activity in regions previously linked to cold reasoning tasks and conscious (explicit) emotion regulation. The findings provide the first neuroimaging evidence for phenomena variously described as motivated reasoning, implicit emotion regulation, and psychological defense. They suggest that motivated reasoning is qualitatively distinct from reasoning when people do not have a strong emotional stake in the conclusions reached.