bluuebunny/crossref_metadata_2025 huggingface dataset:
Innovation in Euromarket hybrid funding instruments
Authors: Marshall Andrew P.
Published: October 2006

This paper considers case studies of the use of innovative hybrid funding instruments—which have features of debt and equity issued by UK companies in the Euromarket. It considers why these instruments were developed and how they utilise the ‘grey areas' in accounting and tax regulations to achieve what managers perceive to be the main benefits of each. One of the major influences on the choice of funding instruments for a number of companies involved in acquisitions in the late 1980s was their accounting and tax treatment. the search was for cost effective finance which at the same time contributed a premium to blunt the purchased goodwill write‐off. Group reserves have no legal significance but goodwill write‐offs can have consequences for a group constrained by borrowing restrictions (based on its balance sheet figures). the concern with the shape of the balance sheet and the ratios calculated using these figures, combined with perceived beliefs about the tax advantages of borrowing led to the development of the Euroconvertible Preference Share issues by subsidiary companies in 1989. the tax authorities removed the attraction of this instrument to issuers. However, the innovative process continued and similar accounting and tax explanations influenced the design of another major category of hybrid—the Convertible Capital Bond. Accounting regulators have reacted to this hybrid by producing new guidelines which have removed its benefits and therefore its attraction to companies. Nonetheless, the process of innovation continues and a new instrument—the Irredeemable Convertible Bond—has been developed.
The cost of bank loans in relation to bonds swapped into a floating rate
Authors: Armitage Seth
Published: October 2006

Banks never lend at less than the interbank floating rate, LIBOR. We argue that this must be because it is insufficiently profitable for those that could lend at less than LIBOR to do so and discuss circumstances in which this would be the case. Using data from 1988–1991, we show that LIBOR varies in relation to the cost of corporate bonds swapped into a floating rate, and suggest that the relative cost of LIBOR may affect bank and bond market pricing policies. the data also indicates that changes in the compensation for credit risk demanded by the bank and bond markets are not synchronous, and that swap rates have an appreciable impact on the cost of bonds swapped into floating.
GP PRACTICE BUDGETS: AN EVALUATION OF THE FINANCIAL RISKS AND REWARDS
Authors: Glynn John J. , Murphy Michael P. , Perkins David A.
Published: October 2006

This paper considers the progress to date of those GP practices which have decided to become fundholding practices. We note that already, within the first year of operation, both GP fundholders and District Health Authorities have developed a number of budget ploys. As part of our work we report on the findings of a pilot survey of GP budget holders in the Kent Family Health Service. We conclude that if budget holding becomes the normal pattern of general practice, there will need to be a considerable development of the financial skills and managerial capabilities of the practices and it may be time for the new GP practice manager to come of age.
CAPITAL ACCOUNTING IN MUNICIPAL CORPORATIONS 1884‐1914: THEORY AND PRACTICE
Authors: Coombs Hugh M. , Edwards John Richard
Published: October 2006

Municipal corporations wielded a vast amount of economic power throughout the period covered by this paper and, as a result, they were the subject of envy, suspicion and criticism. The question of whether depreciation should be charged could not be dismissed as a mere matter of book‐keeping. The inclusion of a charge involved the earmarking of an equivalent amount of money for future use, and the matter was therefore regarded as of fundamental importance for current levels of local taxation and long term financial stability. Public and private sector based accountants, municipal officers, town councillors, ratepayers and academics engaged in a debate which, although stirring strong emotions, was thoughtful, wide ranging and constructive. This paper examines the discourse and its outcomes.
DEVELOPING A CONCEPTUAL FRAMEWORK FOR CENTRAL GOVERNMENT FINANCIAL REPORTING: INTERMEDIATE USERS AND INDIRECT CONTROL
Authors: Rutherford Brian A.
Published: October 2006

This paper argues that the search for external users of public sector financial reports, and for decisions for which users might plausibly need information that could feasibly be provided in general purpose financial statements, has failed empirically and theoretically. The implications for the construction of a conceptual framework for public sector financial reporting are examined. It is suggested that‘intermediate’users operating in an environment of‘indirect control’might form an appropriate basis for a conceptual framework. Some tentative observations about such a framework are made and its application in accounting for central government agencies is explored.
Testing of Variants of the MTHFR and ESR1 Genes in 1798 Finnish Individuals Fails to Confirm the Association with Migraine with Aura
Authors: Kaunisto MA , Kallela M , Hämäläinen E , Kilpikari R , Havanka H , Harno H , Nissilä M , Säkö E , Ilmavirta M , Liukkonen J , Teirmaa H , Törnwall O , Jussila M , Terwilliger J , Färkkilä M , Kaprio J , Palotie A , Wessman M
Published: October 2006

Among the few independently replicated genetic associations in migraine are polymorphisms in the methylenetetrahydrofolate reductase ( MTHFR) and oestrogen receptor ( ESR1) genes. We studied the contribution of these genes to migraine susceptibility by genotyping six MTHFR and 26 ESR1 polymorphisms in 898 unrelated migraine with aura (MA) patients and in 900 unrelated healthy controls. There were no differences in the genotype distributions of the previously migraine-associated SNPs C677T ( MTHFR) and G2014A ( ESR1) between cases and controls ( P-values 0.83 and 0.55, respectively). Thus, we were not able to replicate the previous findings, although our study had considerable power. However, five of the ESR1 SNPs (rs6557170, rs2347867, rs6557171, rs4870062 and rs1801132) that were in strong linkage disequilibrium were nominally associated with MA (uncorrected P-values 0.007-0.034). These results did not, however, remain significant after taking multiple testing into account. Thus it seems unlikely that the studied genes are involved in migraine susceptibility, at least in this sample.
Cities Under Stress: Problems of Development and Decline
Authors: Jacobs Brian D.
Published: October 2006

The problems of cities in developing nations and in the more affluent developed economies exhibit both similarities and differences. Kasarda and Parnell present an important collection of papers about the problems of Third World cities. Gittell deals with aspects of small city regeneration in the United States.
Assessing Environmental Risks: Lessons From Superfund
Authors: Nakamura Robert T. , Church Thomas W. , Mumpower Jeryl L.
Published: October 2006

This essay analyzes the use of risk assessment in Superfund, the controversial American hazardous waste cleanup programme. We argue that risk assessment has been used in three ways in discussing policy options in this programme: as a metric for assessing performance; as a means for resolving conflicts; and as a tool for comparing different environmental initiatives. Use of risk reduction as an analytical tool in European efforts to clean up hazardous waste sites is discussed. We conclude that while risk assessment has potential utility for each of these applications, there are also accompanying technical and political difficulties.
A Dialogue about Risk
Authors: May Peter J.
Published: October 2006

But Is It True?: On the Relationship Between Knowledge and Action in the Great Environmental and Safety Issues of Our Time, Aaron Wildavsky, Harvard University Press, Cambridge (1994) (in press).

Risk Society: Towards a New Modernity, Ulrich Beck, Sage Publications, Newbury Park (19921, 249 pp. (translated by Mark Ritter).

Risk and Blame: Essays in Cultural Theory, Mary Douglas, Routledge, London and New York (1992), 313 pp.

Organizations, Uncertainties, and Risk, James F. Short, Jr. and Lee Clarke (Eds.), Westview Press, Boulder (1992), 355 pp.
Identifying the Right Stuff: Selecting and Training On‐Scene Emergency Commanders
Authors: Flin R.H. , Slaven G.M.
Published: October 2006

This paper examines the selection and training of on‐scene commanders who have responsibility for managing an emergency at the scene of the event, be it a fire, a riot, a battle or an aircraft with a technical problem in flight. It presents a selective review of the findings of a study, commissioned by the Offshore Safety Division of the UK Health and Safety Executive, which examined the selection, training and competence assessment of individuals with emergency command responsibilities in a range of military, public service and commercial organisations. It identifies a set of generic characteristics and competencies for on‐scene commanders and considers how these are identified in the selection process. This is followed by a discussion of training and formal competence assessment. These issues have increasing relevance not only for the military and civil protection agencies but also in an industrial context for site managers, particularly in chemical, petroleum and nuclear plants and in large entertainment venues.
Eritrea: W(h)ither the Jihad?
Authors: Pateman Roy
Published: October 2006

Eritrea and Sudan, two neighbours in the Horn of Africa, have broken off diplomatic relations and war between the former friends is not impossible. Handling the crisis caused through Sudanese sponsorship of a fundamentalist group, Eritrea Jihad, that seeks to overthrow the secular government of Eritrea is the first major test of the diplomatic and political skills of Africa's newest nation. Resolution of the crisis is likely to involve Eritrean measures to improve the lot of its disadvantaged Muslims and Sudan reining in the Jihad forces — leading to dissension within the government and unpredictable shifts in Sudaneses politics.
Modern Management's Role in the Demise of Sustainable Society
Authors: Richardson Bill
Published: October 2006

This paper examines the development of modern strategic management and portrays it as a major problem‐causer in modern society, rather than a problem‐solver. Frederick Taylor's philosophy and practice of scientific management is alive and well, and stronger than ever, in the final decade of the 20th century. Although scientific management is a vital underpinning to strategic development in a highly competitive, productivity‐conscious, organizational world, its intense, single‐minded and tunnelvisioned application raises the paradox of it being at one and the same time, “saint and sinner”. Its “saint” role is that of an economic productivity enhancing, competitive capability bestower. Its “sinner” role arises because of the adverse, and potentially dangerous impact it has on rank and file personnels’commitment to, or acceptance of, the way things are in organizations and society. The paper is intended to give an airing to significant problems which are emerging in a practical and theoretical managerial world which seems otherwise to be blindly, and extremely, embracing scientific management as the rightfully dominant paradigm for modern day management strategy. It suggests tha nature of changes which might need to be made to mainstream management paradigms. The challenge is to create a society based, at least in part, on cultural values of opposite dimensions to those which underpin scientific management.
Enhancing Disaster Planning and Management: The 1990 Nyngan Flood in Australia
Authors: Wills Jules A.
Published: October 2006

Crises have been characterized as situations of extreme collective stress which exhibit the ‘prompt overloading of communication channels, the massive invasion of volunteers on the scene of the crisis, the spreading of rumours, the seemingly irrational aversion of the population to smoothly organized professional relief and immediate allegations concerning who is to be blamed and who is taking advantage of the emergency situation’(Rosenthal, Hart‘t and Charles, 1989: 16). All of these phases, elements and characteristics were present to some degree when, on 23 April 1990, the Bogan River broke through the Nyngan levee in western New South Wales, Australia, and caused damage estimated at AUD$50 million.

Floods occur occasionally in most Australian rivers. The main cause is excessive rainfall but flooding is exacerbated by clearing catchment areas or by blocking or obstructing water courses. In 1819, Governor Macquarie chastised new settlers for their ‘willful and wayward habits of placing their residences within the reach of floods, and in putting at defiance that impetuous element which it is not for man to contend with’(quoted in Higgins and Robinson, 1981). Given the history and frequency of major flooding in Australia (Douglas, 1979), it is reasonable to question why these natural hazards have the routine tendency to become disasters of varying degrees of severity (Jarman and Kouzmin, 1991).

This paper looks at the flooding of Nyngan in 1990 and examines events as they relate to existing and extended models of disaster management and decision‐making.
Correlation between single nucleotide polymorphisms in a calprotectin subunit gene and risk of periodontitis in a Chinese population
Authors: Li QiYan , Meng HuanXin , Zhang Li , Xu Li , Chen ZhiBin , Shi Dong , Feng XiangHui , Zhu XiaoLing , Zhao HongShan , Cao CaiFang
Published: October 2006

S100A8, the light subunit of calprotectin, has been known to be associated with periodontal inflammation. The present study looked to detect whether three polymorphisms in the upstream region of the S100A8 gene are correlated with periodontitis. Three hundred and twenty one subjects, including chronic periodontitis (CP) patients, aggressive periodontitis (AgP) patients and periodontally healthy controls, were recruited. The SNPs rs3795391, rs3806232 and rs3885688 were analyzed by PCR‐RFLP analysis. No person carried the rs3885688 polymorphism in this cohort. For the other two polymorphisms, the combined effects of genotype/allele and gender were shown to be associated with the risk of periodontitis using multivariate logistic regression analysis. The G+ genotype/G allele may be considered to exert a significant protective effect in males against AgP (Genotype: rs3795391: P= 0.032, rs3806232: P= 0.017; Allele: rs3795391: P= 0.024, rs3806232: P= 0.013). Although the combined effects of genotype and gender on CP susceptibility were not observed for these two polymorphisms, there does seem to be increased risk of CP in males with allele A compared to females with allele A (rs3795391: P= 0.008; rs3806232: P= 0.009). Hence we found an important association between polymorphisms in the S100A8 gene and periodontitis in a Chinese population.
Association of PSD‐95 with ErbB4 facilitates neuregulin signaling in cerebellar granule neurons in culture
Authors: Xie Fang , Padival Mallika , Siegel Ruth E.
Published: October 2006

The growth factor neuregulin 1 (NRG) selectively induces an increase in the γ‐aminobutyric acid (GABA)A receptor β2 subunit protein in rat cerebellar granule neurons in culture. We previously demonstrated that NRG acts by triggering ErbB4 receptor phosphorylation and subsequent signaling through the mitogen‐activated kinase (MAPK), phosphatidyl inositol‐3 kinase (PI‐3K) and cyclin‐dependent kinase 5 (cdk5) pathways. In this report we show that the scaffolding protein, PSD‐95, plays a key role in mediating the effects of NRG and that reducing its level attenuates the NRG‐induced increase in β2 subunit expression. PSD‐95 appears to facilitate the effects of NRG through its association with ErbB4, an interaction that is augmented by NRG‐activated cdk signaling. Inhibition of cdk activity with roscovitine attenuates the association of PSD‐95 with ErbB4. The effects of cdk5 are not blocked by U0126, an inhibitor of MAPK signaling, indicating that cdk5 functions independently of cross‐talk with this pathway. These findings raise the possibility that NRG‐induced activation of cdk5 works in part by recruiting PSD‐95, a protein involved in regulating synaptic plasticity, to associate with ErbB4. This interaction may be a positive feedback loop that augments NRG signaling and its downstream effects on GABAA receptor β2 subunit expression.
The role of history vs. demography in shaping genetic population structure across an ecotone: chukar partridges (Alectoris chukar) as a case study
Authors: Randi E. , Tabarroni C. , Kark S.
Published: October 2006

Recent advances in molecular ecology allow better assessment of the role of ecological and evolutionary processes in determining the dynamics of genetic diversity in natural populations. The chukar partridge (Alectoris chukar) is abundant and continuously distributed in the mesic Mediterranean regions of Israel, becoming scarce and patchily distributed in the arid Negev Desert. This demographic transition occurs across a main environmental transition, the Northern Negev ecotone. Populations of chukars along this gradient have been shown to differ from other populations in morphology, bilateral asymmetry, and in allozyme variation. The aim of this study is to infer whether historical (i.e. secondary contact of formerly vicariant populations) or recurrent demographic events (i.e. restriction to gene flow across the ecotone) have shaped the observed patterns of genetic diversity in chukar populations in Israel. We analysed mtDNA control‐region sequences in 216 chukars collected from 28 localities (five distinct geographical regions). Results show that (1) average haplotype diversity is high (h = 0.93) while haplotype divergence is low (π= 0.8%), suggesting that extant populations diversified recently; (2) mtDNA gene diversity does not significantly differ across the distribution range; and (3) haplotype distribution differs among the sampling locations (amova; P < 0.00031). Mantel test and autocorrelation analyses indicate that isolation‐by‐distance may explain the geographical partitioning of genetic diversity. These patterns have likely been produced by complex dynamics between past fragmentation of northern vs. intermediate and southern populations. Late Pleistocene climatic changes, fostering cycles of range contraction and expansion, may have led to genetic differentiation in allopatry, followed by restricted gene flow across secondary contact zones.
Blood in Medieval Cultures
Authors: Bildhauer Bettina
Published: October 2006

Blood was central to medieval medicine, literature, theology and devotion. This article traces some of the characteristic features of blood in medieval texts in these areas, primarily in German from the thirteenth to fifteenth centuries: the invocation of blood as proof; the prohibitions against bloodshed; the misogynist and anti‐Semitic concepts of blood; and the importance of blood in social bodies.
Prospective, paired crossover comparison of multiple, single‐needle plateletpheresis procedures with the Amicus and Trima Accel cell separators
Authors: Fontana Stefano , Mordasini Livio , Keller Peter , Taleghani Behrouz Mansouri
Published: October 2006

BACKGROUND: The Baxter Amicus Version 2.51 (A) and the Gambro BCT Trima Accel Version 5.0 (T) cell separators may produce multiple platelet (PLT) concentrates within a single donation.

STUDY DESIGN AND METHODS: The single‐needle multiple plateletpheresis procedures of the two devices were compared in a prospective, randomized, paired crossover study in 60 donors. The 120 donations were compared for donor comfort, collection efficiency, residual white blood cell (WBC) count, and (in selected patients) corrected count increment (CCI).

RESULTS: The mean PLT yield and the resultant mean number of units per donation were significantly lower for A (6.06 × 1011 vs. 7.48 × 1011 and 2.57 vs. 3.19, respectively, both p < 0.001), in spite of a longer apheresis duration (89 min vs. 79 min; p < 0.001). This resulted in a higher collection rate of T (5.68 × 1011 PLTs/hr vs. 4.10 × 1011 PLTs/hr, p < 0.001). Residual WBC count of every unit was fewer than 5 × 106, but significantly fewer A‐PLT donations contained more than 105 WBCs per unit (1 vs. 9, p = 0.008). Although the ACD‐A consumption was slightly higher for A (489 mL vs. 469 mL, p = 0.04), a trend to a higher frequency of side effects was found for T (42.4% vs. 23.7%, p = 0.06). The 1‐hour CCIs of 33 transfused A‐PLT units were comparable with those of 43 T‐PLT units (11.8 vs. 13.9, p = 0.480).

CONCLUSIONS: Both cell separators showed safe collections of up to 4 PLT units per donation with adequate CCI. T produced a higher PLT yield despite shorter apheresis duration, but with slightly higher residual WBC counts and a trend to a higher side‐effect frequency.
Predictive Power of Heart Rate Variability Used as a Stratifier of Cardiac Mortality After Myocardial Infarction in Patients Discharged With and Without Beta‐Blocker Therapy
Authors: Hartikainen Juha E.K. , Malik Marek , Staunton Anne , Poloniecki Jan , Camm A. John
Published: October 2006

Background: Depressed heart rate variability (HRV) is associated with increased risk for sudden cardiac death after myocardial infarction. Beta‐blocker therapy reduces the risk of sudden cardiac death in patients with recent infarction. There is also evidence that beta‐blockers improve HRV in postinfarction patients. In this study, we investigated whether the association between HRV and cardiac mortality in postinfarction patients is different in those who, on clinical grounds are and are not discharged on beta‐blocker therapy.

Methods: HRV was assessed from 24‐hour ambulatory electrocardiograms before hospital discharge in 438 survivors of acute myocardial infarction. After the recordings, 147 patients were prescribed beta‐blockers and 291 were discharged without beta‐blocker therapy. The patients were followed for at least 2 years using cardiac death and arrhythmic death as clinical endpoints. Patients were dichotomized to depressed and normal HRV at the lowest 30 percentile.

Results: Multivariate logistic regression analysis showed that HRV was a sigificant determinant of cardiac (P < 0.001) and arrhythmic mortality (P < 0.001) in patients who were not on beta‐blocker therapy, whereas it was not a predictor of cardiac or arrhythmic mortality in patients who were taking beta‐blockers. Beta‐blocker therapy was associated with a significantly lower total cardiac mortality and arrhythmic mortality in patients with depressed HRV (P < 0.01 and P < 0.05, respectively). In patients with normal HRV, the reduction of mortality was smaller and remained nonsignificant.

Conclusion: HRV was not a predictor of cardiac mortality in postinfarction patients who were prescribed beta‐blockers before hospital discharge. In addition, beta‐blocker therapy was associated with a lower cardiac mortality, particularly in patients with depressed HRV. Thus, depressed HRV might be considered as an additional indication for beta‐blocker therapy in postinfarction patients.
Autonomic Effects on the QT Interval
Authors: Ahmed Mizra W. , Kadish Alan H. , Goldberger Jeffrey J.
Published: October 2006

Background: This study was designed to evaluate the effects of autonomic tone on the QT interval, using conventional and heart rate independent analysis. Effects of autonomic tone on the QT interval have been studied either using rate correction formulae or during fixed rate atrial pacing, both of which have been associated with problems. Since most autonomic interventions are associated with heart rate changes, separation of “true” autonomic effects from rate related effects on the QT interval is essential.

Methods: Electrocardiographic recordings were performed in 14 healthy volunteers during: (1) sympathetic stimulation (tilt, epinephrine infusion, isoproterenol infusion, and exercise); (2) β‐adrenergic blockade; (3) parasympathetic blockade; (4) autonomic blockade; (5) tilt following autonomic blockade; (6) parasympathetic stimulation (phenylephrine infusion); and (7) isolated α‐adrenergic stimulation (phenylephrine infusion following atropine). The QT interval was adjusted for heart rate using Bazett's formula. Heart rate independent analysis was performed between conditions with similar cycle lengths.

Results: QT interval measurements were reproducible and exhibited the typical QT‐RR relationship. Sympathetic stimulation decreased the RR interval and prolonged the QTc interval. Parasympathetic blockade also increased the QTc. Heart rate independent analysis of the effects of β‐blockade showed a shortening of the QT (from 368.5 ± 20.5 ms to 355.9 ± 17.9 ms; n = 8). Alpha‐adrenergic stimulation also decreased the QT interval from 302.4 ± 16.8 ms to 294.3 ± 17.7 ms (n = 7).

Conclusion: Sympathetic stimulation prolongs the QT interval, while β‐blockade shortens it. Alpha‐adrenergic stimulation also shortens the QT interval. Autonomic effects on the QT interval as assessed by heart rate independent analysis may help separate the true autonomic effects from rate related effects.
Adverse Prognosis of ST Depression on the Resting Electrocardiogram in Stable Patients Following Acute Myocardial Infarction
Authors: Dwyer Edward M. , Case Robert B. , Gillespie John A. , Greenberg Henry M. , Krone Ronald J. , Lichstein Edgar , Moss Arthur J. ,   Multicenter Myocardial Ischemia Research Group
Published: October 2006

Background: The aim of this study was to analyze the characteristics of stable patients with resting ST segment depression on the resting electrocardiogram (ECG) following an acute ischemic event (i.e., infarction or unstable angina) to better understand its association with subsequent cardiac death and nonfatal infarction. The recent Multicenter Study of Myocardial Ischemia (MSMI) demonstrated that the resting ST segment depression had an independent prognostic value.

Methods: We studied clinical features, noninvasive test results and coronary arteriography findings in 99 patients with ST depression on the resting ECG and 837 patients without ST segment depression with respect to endpoints of cardiac death and hospitalization for acute myocardial infarction or unstable angina.

Results: Our results showed that patients with resting ECG ST depression were significantly older with a higher incidence of hypertension, angina, claudication, and tobacco use. ST depression on the resting ECG correlated closely with ST segment depression on the 24‐hour ambulatory ECG and the exercise ECG but not with redistribution on the thallium perfusion scan. Left ventricular diastolic pressure was higher and exercise duration less in patients with ST depression. Although not achieving statistical significance, patients with ST depression did show more extensive coronary disease and a lower ejection fraction.

Conclusions: ECG ST depression was associated with cardiac death and nonfatal reinfarction over the follow‐up period only in patients originally admitted with an acute infarction but not in patients hospitalized for unstable angina. The reason for this appears to be an association of ST depression with increased age, the presence of hypertension, the presence of more severe coronary disease, and more extensive myocardial damage.
Detection of Silent Myocardial Ischemia During Ambulatory Monitoring by Time‐Frequency Power Spectral Analysis
Authors: Kamath Markad V. , Fallen Ernest L. , McArthur Amanda , Runions Joanne
Published: October 2006

Background: The nonstationary conditions of unrestricted ambulatory ECG monitoring preclude any meaningful detection of short‐term transient events by conventional time series methods. Time‐frequency analysis offers a unique approach that tracks the frequency content of the signal as it is changing in time.

Methods: We compared the ability of three methods: time‐frequency, RR interval time series, and global HR power spectra to detect the occurrence of silent ischemia (ST depression > 1.5 mm × 80 ms for at least 2 min) among 17 Holter records. The records were obtained from five patients (age 52 ± 2 years) with angiographic coronary artery stenosis > 70%. Individual segments were analyzed in a blinded fashion by three of the authors (MK, EF, AM).

Results: Neither changes in the RR interval series nor sequential 2.2‐minute power spectra was significantly predictive of ischemia. Conversely, an abrupt loss of variance in the time‐frequency plot was associated with ST depression 82.3% of the time (Chi square = 3.41; P < 0.055). There was a weaker correspondance between the duration of ST depression and loss of autospectral power.

Conclusions: Although a significant correlation (r2= 0.863) was seen between the maximum low frequency power (sympathetic modulation) and sudden decreases in RR interval, there were at least three instances where no detectable change in HR occurred during episodes of ischemia. These preliminary observations offer hope that time‐frequency methods may prove useful in the detection of transient events in the ambulatory ECC record.
Enhanced ECG Signal‐Averaging Techniques: New Applications and Improved Performance
Authors: Lander Paul
Published: October 2006

Background: The signal‐averaged ECG is a widely used and accepted technique for analysis of low‐level cardiac signals. This article reviews a new and enhanced form of ECG signal averaging: the time‐frequency plane Wiener (TFPW) filter.

Methods: The TFPW filter accelerates the process of noise reduction. It facilitates use of signal averaging in settings previously unexplored with the technique, where a limited number of beats may be available.

Conclusion: Example applications of the TFPW filter include improved analysis of ventricular late potentials and analysis of dynamic events, such as transient ischemia.
Classification Accuracy of Electrocardiographic Criteria for Left Ventricular Hypertrophy in Normal Weight and Overweight Older Adults
Authors: Rautaharju Pentti M. , Manolio Teri A. , Siscovick David , Zhou Sophia H. , Gardin Julius M. , Furberg Curt D. , Borhani Nemat O. , Newman Anne ,   CHS Collaborative Research Group
Published: October 2006

Background: We evaluated classification accuracy of ECG criteria at varying levels of left ventricular hypertrophy (LVH) severity according to echocardiographically measured left ventricular mass (LVM) adjusted to body size.

Methods: The test population was derived from the Cardiovascular Health Study (CHS), a population‐based sample of 5201 men and women aged 65 and older, and consisted of 1844 women and 1119 men with adequate quality ECGs and echocardiograms for LVM determination. The criteria evaluated were Sokolow‐Lyon, Cornell voltage, Cornell product, Framingham modification of the Cornell voltage, and the left ventricular mass index (LVMI) of the Novacode ECG program.

Results: With LVH thresholds at upper 95% normal limit for weight adjusted LVM for the CHS population and ECG thresholds adjusted for 95% specificity in normal weight and overweight subgroups, the sensitivity of ECG criteria for LVH was relatively low. It was highest (40.8%) for the Novacode LVMI in normal weight men and for the Framingham criteria (30.9%) in normal weight women, but it deteriorated for both of these criteria in the presence of obesity. The overall performance of the Cornell product and Cornell voltage criteria was least influenced by obesity. The Framingham adjustment for the Cornell voltage criteria for obesity substantially reduced their sensitivity.

Conclusion: The choice of echocardiographic standard, LVH severity level and overweight in the test groups have a strong influence on ECG evaluation results.
A Prospective Study of Atrial Fibrillation After Cardiac Surgery
Authors: Hutchinson Leigh Ann , Steinberg Jonathan S.
Published: October 2006

Background: Atrial fibrillation (AF) is a commonly encountered arrhythmia following cardiac surgery and when sustained, may be associated with significant morbidity.

Methods: This large prospective investigation examined a variety of clinical and P wave signal‐averaged electrocardiogram (SAECG) parameters to identify independent predictors of AF following cardiac surgery. A total of 272 patients underwent P wave SAECG recording and analysis prior to surgery. Information on their clinical, surgical, and hemodynamic characteristics as well as hospital course was collected. Patients were followed during their postoperative course with telemetry and ECGs.

Results: During an observation period of up to 14 days, 79 patients (29%) developed AF 2.5 ± 1.9 days after surgery. Patients who developed AF following cardiac surgery were more likely to be older, undergo valve surgery, to have ejection fraction (EF) < 40%, to have P wave duration on SAECG >140 ms (all P < 0.01), and to take digoxin preoperatively (P < 0.05). A multivariate analysis found that only P wave duration on SAECG >140 ms and EF < 40% were independent predictors of AF following cardiac surgery. The odds ratio of P wave duration on SAECG >140 ms and EF < 40% for the development of AF following cardiac surgery was 3.1 and 2.8, respectively, and 8.7 when combined.

Conclusions: Thus, the presence of preexisting abnormal atrial substrate as detected by P wave prolongation on SAECG, and implicated by EF < 40%, clearly predicted a higher risk of AF following cardiac surgery and may provide clinicians with an effective means of identifying those at greatest risk.
A Comparative Analysis of Commercial Software for Signal‐Averaged Electrocardiography
Authors: Turitto Gioia , Mansoor Shahid , Rao Srisha , Edward B. Caref M.A.  , El‐Sherif Nabil
Published: October 2006

Background: Lack of standardization of software algorithms to identify the end of QRS for time‐domain analysis of the signal‐averaged electrocardiogram may limit the comparison of results obtained with different machines.

Methods: To study this problem, 50 normal volunteers underwent signal‐averaged electrocardiogram with ART 1200 EPX and Corazonix Predictor units in random sequence, collecting an equal number of beats. Data were analyzed with five different commercial softwares by ART and Corazonix.

Results: Comparison of QRS duration, duration of low amplitude signals, and root mean square voltage of last 40 ms of QRS at two high‐pass filter settings (25 and 40 Hz) showed significant differences among softwares.

Conclusions: Standardization of software for time‐domain analysis of the signal averaged electrocardiogram is warranted; until then, normal values for signal averaged electrocardiogram parameters will have to be appropriately selected for each study, according to the software utilized.
Absence of Gender Difference in Circadian Trends of QT Interval Duration
Authors: Anselme Frédéric , Maison‐Blanche Pierre , Cheruy Pascale , Saoudi Nadir , Letac Brice , Coumel Philippe
Published: October 2006

Background: The long‐term circadian behavior of the QT interval duration was comparatively evaluated in females and in males. The corrected QT interval duration is known to be longer in females than in males, and this gender difference persists after double autonomic blockade.

Methods: Our population consisted of 32 young healthy subjects (16 males). Twenty‐four‐hour ambulatory ECG recordings were processed by QT analysis software. All sinus complexes were averaged on a 30‐second time basis. The averaged template was defined by a single QT apex (QTa) interval and its mean RR interval. The circadian behavior of ventricular repolarization was assessed by the nocturnal lengthening of QTa at an identical RR interval, and by the respective diurnal and nocturnal QT/AR relationship in both genders.

Results: The corrected QTa was longer in females (318 ± 20 vs 294 ± 13 ms, P = 0.0003). The correlation coefficients of the QTa/RR regression lines were >0.75, whatever the gender and the circadian period considered. In both genders, diurnal slopes were higher than nocturnal ones (0.15 ± 0.01 vs 0.09 ± 0.03 in males and 0.18 ± 0.04 vs 0.09 ± 0.05, P = NS), and the nocturnal lengthening of QTa was on the same range (25 ± 12 vs 17 ± 12 ms, P = NS).

Conclusion: The longer corrected QT interval in females is not associated with a specific static or dynamic circadian behavior of QT interval.
Evaluation of Outpatient Arrhythmias and Pacemakers Utilizing Transtelephonic Monitoring Devices
Authors: Dubner Sergio , Sztyglic Elena , Boskis Pablo , Roa Graciela , Boskis Bernardo
Published: October 2006

Background: The purpose of this trial was to evaluate a patient actuated transtelephonic cardiac monitoring system in order to document cardiac arrhythmias and cardiac pacemaker function.

Material: Eighty‐two patients were prospectively evaluated, 69 with pacemaker (group I) and 13 with symptomatic arrhythmias (group II). Two different recorders were used: a memory loop‐recorder (KH) and a wrist‐worn recorder (HW). Both of them were implemented using a small, portable, battery‐powered transmitter, which monitors a modified V5 in KH and a lead 1 with the HW over regular nondigital pulse telephone lines.

Results: In group I, 54 patients used single chamber pacemakers, 2 VDDR, and 13 used dual chamber devices. In group II, all patients included referred palpitations as their symptom. In group I, 248 registers were made using the KH and 50 with the HW. Recordings were made with KH had a 96% accuracy in the diagnosis of the ECG, while HW recordings failed to detect the QRS and the spike in 52% of the cases. Arrhythmia patients (group II) made 65 recordings with KH, all symptomatic: 28 were ventricular ectopic beats (23 isolated, 4 bigeminy, and 1 coupled ventricular ectopic beats); 9 supraventricular ectopic beats (isolated); 18 episodes of sinus tachycardia; and 10 normal sinus rhythm. Artifact was present partially in 6 other recordings, but did not affect the diagnosis. Two patients made no recordings and were excluded from the trial (group I).

Conclusions: The loop‐recording transtelephonic monitoring system is an excellent tool for the evaluation of patients with symptomatic arrhythmias and pacemaker. The memory KH had an excellent performance, even over regular telephone lines. The accuracy of the HW recordings was low and failed to evaluate the QRS, probably due to the direction of the AQRS vector.
Relationship Between Heart Rate Variability and Cardiovascular Risk Factors in Middle‐Aged Males
Authors: Pikkujämsä Sirkku M. , Huikuri Heikki V. , Ikäheimo Markku J. , Airaksinen K. E. Juhani , Rantala Asko O. , Lilja Mauno , Savolainen Markku J. , Reunanen Antti , Kesäniemi Y. Antero
Published: October 2006

Background: Abnormal autonomic control of heart rate is associated with an inreased risk of cardiovascular morbidity and mortality. There are few population‐based reports on the interindividual variation and determinants of cardiac control in healthy middle‐aged males.

Methods: Autonomic modulation of heart rate was studied in 172 randomly selected middle‐aged males (mean age 50 ± 6 years) by measuring the heart rate variability (HRV), which was related to life style data, personality type, blood pressure, lipid analyses, results of the 2‐hour glucose tolerance test and left ventricular function.

Results: Large interindividual variation was observed in the standard deviation of RR intervals (mean 59 ± 20 ms; coefficient of variation (CV) 34%) compared to variation of the average heart rate (mean 76 ± 11 beats/min, CV 14%). When analyzed as normalized units, marked interindividual variation was observed in the low (CV 16%) and high frequency component (CV 37%). The total power of HRV had significant indirect univariate correlations with age, blood pressure, body mass index, 2‐hour blood glucose level, fasting and 2‐hour serum insulin levels, triglyceride level, and a direct correlation with left ventricular fractional shortening. In a multiple regression analysis, the total power of HRV was best predicted by age (β=−0.27, P = 0.0002), followed by the fractional shortening (β= 0.25, P = 0.0004), systolic blood pressure (/3 =−0.2 1, P = 0.005) and 2‐hour insulin level (β=−0. 9, P = 0.01).

Conclusions: Overall HRV has a wide interindividual variation and is related to several cardiovascular risk factors, perhaps contributing to the observed association between low HRV and cardiovascular mortality. Normalized units of HRV reflecting sympathovagal balance are unrelated to age, life style, or cardiovascular risk factors.
The Signal‐Averaged ECG Obtained by a New Digital Holter Recording System
Authors: Schneider Michael A. E. , Plewan Andreas , Schmitt Claus , Meinertz Thomas
Published: October 2006

Background: The implementation of signal‐averaged analysis in the Holter recording may increase cost‐effectiveness and enables further insights into pathophysiological links between arrhythmia genesis and time related modulating factors. This study assesses the feasibility of a new digitizing long‐term recorder system to perform a signal‐averaged analysis and compares the data with the results achieved by an established bedside real‐time recording system.

Methods: The study was performed prospectively in 22 patients. The digital recorder FD‐3 obtained a 3‐channel 24‐hour Holter monitoring. For the signal‐averaged ECG analysis, a template averaging was achieved in 5‐minute periods. The interpolated sampling rate was 1024 Hz. The signal‐averaged ECG by bedside real‐time system was performed using the Predictor system. At 25–250 Hz and 40–250 Hz band‐pass filter, 4 FD‐3 epochs acquired in a 6‐hour interval were chosen and the mean values of QRS, root mean square (RMS), and low amplitude signal (LAS) were compared with the data obtained by one Predictor measurement.

Results: The regression analysis shows a positive correlation between the FD‐3 and Predictor data of QRS, RMS, and LAS at both filter settings except for LAS at 25–250 Hz. Regarding the late potential classification, at 25–250 Hz 4 of 22 (18%) FD‐3 and Predictor classifications were not coherent and at 40–250 Hz only 2 of 22 (9%) classifications did not correlate.

Conclusions: The FD‐3 recorder is feasible to perform a signal‐averaged ECG analysis. Especially at 40–250 Hz, the late potential classification shows a concordant distribution.
Localization of Myocardial Infarction Based on Learning Vector Quantization Networks Applied to ST Elevations of the 12‐Lead ECG
Authors: Reinhardt Lutz , Vesanto Riikka , Montonen Juha , Fetsch Thomas , Mäkijärvi Markku , Sierra Gilberto , Katila Toivo , Breithardt Günter
Published: October 2006

Background

During recent years artificial neural networks have been proposed as a diagnostic tool in different fields of cardiology. Most of the studies have utilized the multilayer perceptron with backpropagation learning rule for the design of the network. As a new approach, Learning Vector Quantization (LVQ) which belongs to the class of competitive learning networks, was developed particularly for classification problems. So far there are no data available on the application of LVQ for classification tasks in cardiology. The present study aims at investigating the performance of LVQ for localization of myocardial infarction (Ml) based on ST elevations in the standard 12‐lead ECG.

Methods

Altogether, 769 male patients (age 53 ± 7 years) with an acute Ml were included into the study. Three hundred fifty‐three patients (46%) presented with anterior and 416 patients (54%) with inferior Ml based on typical changes in the standard 12‐lead ECG. Standardized ST elevations in all 12 leads were used as input structure for the network. The performance of the network was studied using two different learning and test sets. The influence of the number of reference vectors and training steps on the classification accuracy for infarct location was investigated.

Results

The highest classification accuracy of 88.6% for infarct location was achieved using the learning set with 66% of all patients. This setup was based on five reference vectors and 200 training steps. The best accuracies for anterior Ml were higher as compared to inferior infarctions in both the test and training set. Using more than 50 reference vectors resulted in a decrease of classification accuracy due to overtraining of the network.

Conclusion

Appropriately initialized and trained artificial neural networks based on LVQ give a high accuracy for localization of Ml using only ST elevations of the standard 12‐lead ECG.
Quantification of Prevalence of Asymptomatic Ventricular Arrhythmias in Patients with Heart Failure
Authors: Anastasiou‐Nana Maria I. , Menlove Ronald L. , Mason Jay W.
Published: October 2006

Background

Ventricular arrhythmias (VAs) are recorded in many patients with chronic heart failure. The present study was designed to prospectively determine and quantify the prevalence of asymptomatic VAs in this patient population.

Methods

One hundred and two patients, 82 men and 20 women (median age 61 years) with NYHA Functional Class II (n = 50, 49%) and III (n = 52, 51%) heart failure were prospectively assessed with 24‐hour ambulatory ECGs.

Results

Rare premature ventricular complexes (PVCs) (<100/24 hours) were observed in 22 (21.6%), moderately frequent (101–1000/24 hours) in 31(30.4%), and frequent (>1000/24 hours) in 49 (48.0%) patients. A significantly greater prevalence of <100 PVCs/24 hours was observed in male compared to female patients (P < 0.03) and in those over 61‐years old compared to younger patients (P < 0.01). There was a significantly greater incidence of >0 repetitive PVCs (RPVCs) per 24 hours and >25 RPVCs/24 hours in patients with low ejection fraction (EF), defined as either ≤0.30 (P = 0.003) or ≤ 0.22 (P = 0.02). The occurrence of VT events was significantly associated with EF ≤ 0.30 (P = 0.007). The prevalence of >100 PVCs/24 hours was significantly higher in patients treated with digoxin (P < 0.02).

Conclusions

PVCs are more frequently observed and more frequent in number in patients with heart failure than in normal subjects, and arrhythmia severity correlates with severity of left ventricular dysfunction.
Functional Late Potential Analysis With Exercise Testing to Identify Patients Prone to Ventricular Tachycardia After Myocardial Infarction
Authors: Steinbigler Peter , Haberl Ralph , Schmücking Ingo , Dorwarth Uwe , Mattke Sören , Hoffmann Ellen , Steinbeck Gerhard
Published: October 2006

Objective: Exercise induced ischemia or heart rate acceleration may unmask late potentials or provoke functional changes, which might be important factors to improve the low positive predictive value of late potential analysis at rest for postinfarction risk stratification. However, methodological refinements are required to detect late potentials with exercise.

Methods: We, therefore, investigated the surface‐electrocardiogram in 100 patients after myocardial infarction (50 with sustained ventricular tachycardia [group I], 50 patients without ventricular arrhythmias [group II], and in 15 normals before and immediately after bicycle exercise test using Spectrotemporal Mapping (STM) with fast Fourier transform (FFT) and Simson method and introduced selective signal averaging.

Results: In group I, 30 out of 50 patients showed late potentials at rest, after selective signal averaging also recognizable immediately after exercise in all of these patients, however, with a time‐shift of 18 ± 13 ms into the ST‐segment. Twelve out of 50 patients of group I with only transient late potentials tended to have inducible and recurrent ventricular tachycardia with a shorter cycle length. In group II, 4 out of 50 patients had late potentials at rest and 2 out of 46 patients developed them during exercise. Transient pathological Simson method was associated with transmural ischemia.

Conclusions: Thus, detection of the effects of exercise on late potential analysis is possible with selective signal averaging immediately after exercise. Exercise unmasks late potentials not detectable at rest by their time‐shift into the ST‐segment. Using this method, patients that would have been lost with conventional late potential analysis, could be identified.