bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of long‐term cigarette smoking on immunoglobulin E‐mediated allergy, pulmonary function, and high‐resolution computed tomography lung densitometry in elderly patients with asthma
Authors: Mitsunobu F. , Ashida K. , Hosaki Y. , Tsugeno H. , Okamoto M. , Nishida N. , Nagata T. , Tanizaki Y. , Tanimoto M.
Published: January 2004

Background
Smoking is the most important cause of chronic obstructive pulmonary disease (COPD). However, the influence of cigarette smoking on the pathogenesis of asthma in the elderly remains controversial. This study attempted to clarify the influence of cigarette smoking on elderly asthmatics.

Methods
Forty‐eight asthmatics over 70 years old (25 ex‐smokers and 23 never‐smokers) and 20 patients with COPD over 70 years old (all ex‐smokers) were studied to determine the influence of cigarette smoking on IgE‐mediated allergy (total IgE, IgE antibodies against inhalant allergens, bronchial hyper‐responsiveness (BHR), generation of leukotriene (LT) B4 and C4), pulmonary function, and the relative area of lung showing attenuation values less than −950 Hounsfield units (RA950) on high‐resolution computed tomography scans.

Results
The incidence of positive IgE antibodies against inhalant allergens, BHR, and the generation of leukotriene B4 (LTB4) by leucocytes were significantly increased in patients with a history of smoking compared with those without. Residual volume (%RV) was significantly increased, and diffusing capacity for carbon monoxide was significantly decreased in ex‐smokers with asthma and COPD compared with never‐smokers with asthma. Inspiratory RA950 and ratio of expiratory RA950 to inspiratory RA950 were significantly larger in asthmatics with a smoking history than in those without, and in COPD patients than in asthmatics.

Conclusion
Cigarette smoking enhances the production of IgE antibodies, BHR, and generation of LTB4 by leucocytes in elderly asthmatics. Increased hyper‐inflation or emphysematous changes of the lungs expressed by increased RA950, closely related to %RV, was more frequently observed in ex‐smokers compared with never‐smokers.
Comparative prevalence of sensitization to common animal, plant and mould allergens in subjects with asthma, or atopic dermatitis and/or allergic rhinitis living in a tropical environment
Authors: Montealegre F. , Meyer B. , Chardon D. , Vargas W. , Zavala D. , Hart B. , Bayona M.
Published: January 2004

Background and objectives
Current information suggests that the expression of allergic diseases is determined by the exposure and nature of the allergen. The objectives of the present study were to determine if the nature of allergenic exposition to animal, plant or fungal allergens influenced the clinical manifestations of atopic dermatitis (AD), allergic rhinitis (AR) or asthma (AS) in patients living in a tropical environment. The prevalence and degree of sensitization to these allergens were analysed by age and gender.

Subjects and methods
A total of 1496 atopic cases, grouped according to the primary diagnosis of AD or AR or AS, were skin tested using a standardized allergen panel. Participants were categorized by age groups. The atopic index (AI) and mean weal diameter (MWD) as well as the prevalence of positive skin tests were determined for each of the patient groups and compared by age groups.

Results
The prevalence of atopy as well as the AI and the MWD peaked at 6–15 years of age and declined thereafter. In all the patients tested, the prevalence of sensitization was, in decreasing order; dust mites 94.3%, cockroach 41.5%, pets 31.5%, plant allergens 31.1% and fungal 19.4%. Eight hundred and ninety‐three atopic patients were exclusively sensitized only to animal allergens. Of these, 38.4% had AD, 31.3% had AR and 30.5% with AS.

Conclusion
These data demonstrate that for patients with AD, AR and AS living in a tropical environment, the prevalence of positive skin reactions to animal allergens is highest followed by plant and fungal allergens. We did not observe any association between the type of allergen and clinical manifestations. The index of atopy was similar for both sexes. The prevalence and degree of sensitization were shown to peak in young adults independent of the allergen in AD and AR patients.
Vaccines for birch pollen allergy based on genetically engineered hypoallergenic derivatives of the major birch pollen allergen, Bet v 1
Authors: Mahler V. , Vrtala S. , Kuss O. , Diepgen T. L. , Suck R. , Cromwell O. , Fiebig H. , Hartl A. , Thalhamer J. , Schuler G. , Kraft D. , Valenta R.
Published: January 2004

Background
We have recently engineered recombinant derivatives of the major birch pollen allergen Bet v 1 (rBet v 1 fragments and trimer) with strongly reduced allergenic activity.

Objective
The aim of this study was the in vivo characterization of potential allergy vaccines based on Al(OH)3‐adsorbed genetically modified rBet v 1 derivatives in mice.

Methods
BALB/c mice were immunized either with courses of nine injections of increasing doses of Al(OH)3‐adsorbed rBet v 1 wild‐type, rBet v 1 fragments, rBet v 1 trimer or Al(OH)3 alone in weekly intervals or with three high‐dose injections applied in intervals of 3 weeks. Humoral immune responses to rBet v 1 wild‐type and homologous plant allergens were measured by ELISA and Western blotting, and the ability of mouse antibodies to inhibit the binding of allergic patients IgE to Bet v 1 was studied by ELISA competition experiments.

Results
In both schemes, hypoallergenic rBet v 1 derivatives induced low IgE but high IgG1 responses against rBet v 1 wild‐type. The IgG1 antibodies induced by genetically modified rBet v 1 derivatives cross‐reacted with natural Bet v 1 and its homologues from alder (Aln g 1) as well as hazel (Cor a 1) and strongly inhibited the binding of birch pollen allergic patients' IgE to Bet v 1 wild‐type.

Conclusion
Genetically modified hypoallergenic rBet v 1 derivatives induce blocking antibodies in vivo. Their safety and efficacy for the treatment of birch pollen and associated plant allergies can now be evaluated in clinical immunotherapy studies.
Verbal short‐term memory in Down's syndrome: An articulatory loop deficit?
Authors: Vicari S. , Marotta L. , Carlesimo G. A.
Published: January 2004

Background  Verbal short‐term memory, as measured by digit or word span, is generally impaired in individuals with Down's syndrome (DS) compared to mental age‐matched controls. Moving from the working memory model, the present authors investigated the hypothesis that impairment in some of the articulatory loop sub‐components is at the base of the deficient maintenance and recall of phonological representations in individuals with DS.

Methods  Two experiments were carried out in a group of adolescents with DS and in typically developing children matched for mental age. In the first experiment, the authors explored the reliance of these subjects on the subvocal rehearsal mechanism during a word‐span task and the effects produced by varying the frequency of occurrence of the words on the extension of the word span. In the second experiment, they investigated the functioning of the phonological store component of the articulatory loop in more detail.

Results  A reduced verbal span in DS was confirmed. Neither individuals with DS nor controls engaged in spontaneous subvocal rehearsal. Moreover, the data provide little support for defective functioning of the phonological store in DS.

Conclusions  No evidence was found suggesting that a dysfunction of the articulatory loop and lexical‐semantic competence significantly contributed to verbal span reduction in subjects with DS. Alternative explanations of defective verbal short‐term memory in DS, such as a central executive system impairment, must be considered.
Sex differences in performance over 7 years on the Wechsler Intelligence Scale for Children – Revised among adults with intellectual disability
Authors: Kittler P. , Krinsky‐McHale S. J. , Devenny D. A.
Published: January 2004

Background  The aim of this study was to explore changes related to sex differences on the Wechsler Intelligence Scale for Children – Revised (WISC‐R) subtest performance over a 7‐year interval in middle‐aged adults with intellectual disability (ID). Cognitive sex differences have been extensively studied in the general population, but there are few reports concerning individuals with ID. Sex differences are of current relevance to actively debated issues such as cognitive changes during menopause and risk for Alzheimer's disease. Given that hormonal effects on cognition have been observed in the general population, particularly in areas such as visuospatial processing, and individuals with Down's syndrome (DS) have been reported to be hormonally and reproductively atypical, we analysed our data to allow for the possibility of an aetiology‐specific profile of sex differences for these adults.

Methods  The WISC‐R subtests were administered in a longitudinal study, as part of a more comprehensive test battery, at least twice within 7 years. Participants were 18 females with ID without DS [age at first test time (time 1): mean = 40.5; IQ: mean = 59.3], 10 males with ID without DS (age at time 1: mean = 42.4; IQ: mean = 59.4), 21 females with DS (age at time 1: mean = 37.9; IQ: mean = 51.6), and 21 males with DS (age at time 1: mean = 40.3; IQ: mean = 54.3). All participants were in the mild to moderate range of ID and were displaying no changes suggestive of early dementia.

Results  Females, regardless of aetiology of ID, exhibited a robust superiority on the coding subtest, which parallels the widely reported difference among adults in the general population. Additionally, there was a decline in overall performance during the 7‐year study interval, particularly on the verbal subscale subtests, but there was no evidence of sex‐differentiated decline. There were also marginal sex by aetiology interactions on the object assembly and block design subtests, suggesting that males with unspecified ID might perform better than their female peers, but among adults with DS, females might do better than males.

Conclusions  This study supports the presence of cognitive sex differences in the population with ID as indicated by female superiority on the WISC‐R coding subtest. Extending this observation to adults with ID has implications for explanations of female advantage on this task, which now have to account for its presence among individuals with a broader range of intellectual capabilities, more atypical developmental histories and more varied genotypes than previously considered. Trends towards sex by aetiology interactions on the two visuoconstructive subtests, while marginal, were sufficient to warrant continued consideration of the idea of a distinct profile of sex differences for adults with DS and to justify looking at the effects of sex separately within different aetiologies of ID.
Re‐injecting spontaneity and balance in family life: parents’ perspectives on recreation in families that include children with developmental disability
Authors: Mactavish J. B. , Schleien S. J.
Published: January 2004

Methods Grounded in the naturalistic paradigm, a mixed‐method research design (survey questionnaire,n = 65; and interview,n = 16) was used to explore the nature and benefits of, and constraints to, family recreation in families that included children with developmental disability. Statistical analyses were conducted on the quantitative data, while key theme and constant comparative methods were used to analyse the qualitative data.

Results These analyses revealed that family recreation most often involved small combinations of family members – usually mothers and their children – in physical recreation activities (e.g. swimming, walking, bike riding). Parents viewed these interactions as beneficial for enhancing family relationships and providing children, particularly those with a disability, opportunities for skill and self development within an accepting and supportive environment.

Difficulties in coordinating family members schedules, finding activities to accommodate wide age and skill ranges, planning demands, and limitations in marketing and promotional materials were among the constraints most commonly identified in relation to the family as a whole and the children with developmental disability. Links to existing family and leisure research, family systems theory, and considerations for future research also are discussed.
Sentence memory of individuals with Down's syndrome and typically developing children
Authors: Seung H.‐K. , Chapman R.
Published: January 2004

Background  Individuals with Down's syndrome (DS) have an auditory short‐term memory span disproportionately shorter than the non‐verbal mental age (MA). This study evaluated the Baddeley model's claim that verbal short‐term memory deficits might arise from slower speaking rates (and thus less material rehearsed in a 2 s passive store) by using the sentence memory subtest of the Stanford‐Binet. Previous work had shown digit span recall speaking rate to be comparable to the examiner's slow rate (one syllable per second) for both DS and language‐matched participants.

Method  Thirty individuals with DS were compared to two control groups [non‐verbal MA‐matched and mean length of utterance (MLU)‐matched] on the sentence span and speaking rate for the longest verbatim recalled sentence. Sentence stimuli were presented at a normal speaking rate.

Results  The DS group had shorter sentence memory span than the MA‐matched group and a faster, rather than slower, speaking rate (syllables per second) than the MLU‐matched controls.

Conclusions  Language production level accounted for a substantial portion of the variance in the sentence memory span in the DS group. Thus, language production skill, rather than speaking rate, predicts variability in verbal memory span.
Can Corporate Governance be Rated? Ideas based on the Greek experience
Authors: Tsipouri Lena , Xanthakis Manolis
Published: January 2004

The paper presents an attempt to quantify the compliance of Greek companies with international best practices. Based on 37 indicators (composed out of 54 questions) it was found that Greek companies demonstrate a fairly satisfactory degree of compliance with OECD guidelines. Their weak points lie in: the role of stakeholders and corporate social responsibility; the organisation of CG; the effective role of the independent members of the board (which may be attributed to the small size of the pool of potential independent board members); disclosure of remuneration; and risk management. Methodologically, the merit of the exercise lies in its approach towards the creation of “collectively subjective” weightings, an effort to discuss the benefits of separating the rating of the market from the rating of companies and the discussion on typologies of work that can be effectively performed through rating exercises.
On the Role of the Board of Statutory Auditors in Italian Listed Companies
Authors: Melis Andrea
Published: January 2004

This paper discusses the role of the board of statutory auditors as a monitoring device within the prevailing Italian corporate governance system, characterised by the presence of a strong blockholder. We describe the structure and functioning of the board of statutory auditors in the listed companies in terms of size, composition, method of appointment, powers, and duties after the changes due to the Draghi reform and the Preda Code of conduct.
Mandatory Subordinated Debt and the Corporate Governance of Banks
Authors: Hamalainen Paul
Published: January 2004

Given current debates on the future direction of bank regulatory design, the objective of this paper is to raise awareness of a new and potentially significant tool in the corporate governance of banks. Public policy proposals to improve the nature of bank regulation through private‐sector solutions and, in particular, mandatory subordinated debt market discipline provide such an opportunity. This paper argues that apart from creating an additional class of bank stakeholder whose interests align with the risk‐reduction objectives of the regulatory authorities, a suitable mandatory subordinated debt policy (MSDP) could also provide a new and meaningful voice in the corporate governance of banks.
Regulation of UK Corporate Governance: lessons from accounting, audit and financial services
Authors: Dewing Ian P. , Russell Peter O.
Published: January 2004

This paper explores current debates and trends in regulation and examines their relevance to the evolution of UK corporate governance codes of practice. In particular, the paper explores frameworks drawn from the regulation of financial services, accounting and audit, and discusses whether there are lessons to be learnt from them for the regulation of UK corporate governance. Because of trends in regulation, and in the light of empirical evidence and recent events, especially post‐Enron, an appropriate structure for the regulation of UK corporate governance might be based on that of financial services.
Political Psychology in Canada
Authors: Nesbitt‐Larking Paul
Published: January 2004

Although a number of political psychologists are active in Canada, there has been relatively little self‐conscious development of the field. This article brings together contributions from political science and social psychology in Canada in an attempt to identify aspects of Canadian distinctiveness in the field of political psychology, notably the balance between mainstream and eclectic tendencies.
Two Egocentric Sources of the Decision to Vote: The Voter's Illusion and the Belief in Personal Relevance
Authors: Acevedo Melissa , Krueger Joachim I.
Published: January 2004

The decision to vote in a national election requires a choice between serving a social good and satisfying one's self‐interest. Viewed as a cooperative response in a social dilemma, casting a vote seems irrational because it cannot have a discernible effect on the electoral outcome. The findings of two studies with undergraduate samples suggest that some people vote not because they set aside self‐interest, but because they expect their own behaviors to matter. Two psychological processes contribute to this belief: the voter's illusion (the projection of one's own choice between voting and abstention to supporters of the same party or candidate), and the belief in personal relevance (the belief that one's own vote matters regardless of its predictive value for the behavior of others). The rationality of these two egocentric mechanisms depends on the normative framework invoked. Their relevance for actual voting behavior is indicated by their ability to account for four types of variation in turnout rates.
Reducing Burglary and Fear among Older People: An Evaluation of a Help the Aged and Homesafe Initiative in Plymouth
Authors: Mawby Rob
Published: January 2004

Despite their low levels of risk, older people have been targeted by a number of crime reduction initiatives. This article describes an evaluation of one burglary reduction initiative in Plymouth that involved the local Plymouth Homesafe scheme and Help the Aged. The scheme clearly targeted the more vulnerable groups within the community, and clients were extremely positive about the service and its implementation. However, there was little evidence that they expressed lower levels of fear of crime than did older people in general. This leads to a discussion of different levels of vulnerability and the way different subcategories of client perceived and benefited from the scheme.
Governmentality by Network in English Primary Healthcare
Authors: Sheaff Rod , Marshall Martin , Rogers Anne , Roland Martin , Sibbald Bonnie , Pickard Susan
Published: January 2004

In England, the quality of clinical work is being regulated in new ways following recent developments in “clinical governance” policy and apparent failures in the previous system of medical self‐regulation. Using multiple case studies, this paper examines how these changes are affecting professional governmentality and discipline in general practice. Formal organizational structures play little role in clinical governance there. Clinical quality is managed largely through semi‐formal networks, relying on medical self‐surveillance. Compliance is achieved largely by discursive appeals to the legitimacy of clinical governance, but local GPs’ leaders also argue that governments might otherwise regulate medical practice more actively. As yet the effects of clinical governance activity on service delivery are slight. Professional self‐regulation is replacing permissive exception management with more collegial, directive methods.
Aquinas, Merit, and Reformation Theology after the Joint Declaration on the Doctrine of Justification
Authors: Root Michael
Published: January 2004

Lutheran considerations of Aquinas have been shaped by the Reformation division. Can a Reformation consideration of Aquinas on merit move beyond either false contrast or false harmonization? Merit plays a limited, but important role in Aquinas' understanding of God's movement of the human self toward its end of eternal life. Lutheran differences from Aquinas on merit also focus on eternal life. While much of the difference is rooted in differences of theological perspective, just this difference of perspective must be further explored. Aquinas' understanding of merit challenges Lutheran theology's understanding of the self and its role in the Christian life.
On Denying the Right God: Aquinas on Atheism and Idolatry
Authors: Turner Denys
Published: January 2004

Thomas Aquinas appears not to have been intellectually challenged by formal atheisms, nor are his 'five ways' of proving the existence of God best understood as arguments with formal statements of philosophical atheism. But his emphatically 'negative' theology does seem to offer a response to an over‐optimistic and potentially idolatrous 'affirmativeness', and we might see the relevance of this negative theology as challenging atheisms of our times to come up with more radical forms of denial than they customarily achieve. In the light of this account of Thomas' natural theology, how are we to view his 'five ways'? As on the one hand valid as rational proofs and at the same time as avoiding the pitfalls of a Scotist 'onto‐theological' metaphysics.
The asian financial crisis and the natural rate of unemployment: Estimates from a structural var for the newly industrializing economies of asia
Authors: Groenewold Nicolaas , Tang Sam Hak Kan
Published: January 2004

Abstract.   We use a structural vector autoregressive model to estimate the natural rate of unemployment for Hong Kong, Korea, Singapore and Taiwan for the period 1982–2000. Our results show that the dramatic rise in the unemployment rate observed in Hong Kong and Korea was mainly the result of demand shocks rather than structural changes, while in Singapore the unemployment rate rise reflected almost entirely a rise in the natural rate. Taiwan's natural rate has been relatively stable. We offer explanations for these different results in terms of the different economic characteristics (particularly labor market features) of the four countries.
The Reporting Trajectories of Top Homicide Cases in the Media: A Case Study of The Times
Authors: Soothill Keith , Peelo Moira , Pearson Jayn , Francis Brian
Published: January 2004

Abstract: This study describes the reporting trajectories of the 13 cases that received the most coverage in a leading British newspaper, The Times, over a period of 23 years (1977 to 1999 inclusive). We have classified these as ‘mega‐cases’. This approach moves beyond merely measuring the coverage of cases to charting how cases can escalate to become ‘moral panics’, move into a shared ‘general knowledge’ of killing or, in some cases, come to occupy iconic status. Some ‘mega’ cases fade from consciousness when viewed over a period of time. In ‘mega‐cases’ there is an unexpected ‘primary incident’ that makes the case newsworthy in the first instance. Then the ‘formal process’ helps to manage a homicide within accepted and acceptable boundaries. In broad terms, the media trajectories of these ‘mega‐cases’ following the ‘primary incident’ are predictable. However, further unexpected ‘incidents’ unrelated to ‘process’– suicides, attacks by other prisoners, escapes – challenge the predictability of these ‘mega‐cases’. The trajectories of homicide cases that begin to link in with wider societal agendas are the most difficult to predict.
Litigation as a Strategy in Penal Reform
Authors: Valier Claire
Published: January 2004

Abstract: The criminal justice arena within which penal reform groups now operate requires them to develop new strategies. With this context in mind, the significance of a recent action for judicial review is discussed. In this landmark case, the Howard League for Penal Reform successfully challenged the legality of the Home Secretary's policy on children held in young offender institutions. The article describes the changing strategies employed by the League, and particularly contrasts ‘persuasion and influence’ with the turn to litigation. The ability of judicial review, as a specific kind of litigation, to further the goals of penal reform, is considered. Two principal arguments are advanced, namely: (i) that legal strategies are an important means through which penal policy is contested, and (ii) that legal actions contribute to the pursuit of informed modes of public engagement with questions about criminal justice.
Thinking About the Future of Probation Inspection
Authors: Morgan Rod
Published: January 2004

Abstract: The functions of inspectorates are, and should be, the Chief Inspector argues, symbiotically related to the characteristics of the services they inspect. Thus HMIProbation had to change when, in April 2001, the 54 local probation services in England and Wales became the National Probation Service. HMIProbation has developed a new inspection methodology reflecting this. The focus is now less on processes and more on outcomes. Further, if improving the working of the criminal justice system generally is the object, the Chief Inspector maintains that there is a case for there being a single inspectorate covering the police, the Crown Prosecution Service, the criminal courts, and the Probation and Prison Services.
Massive dolomitization of a Messinian reef in the Great Bahama Bank: a numerical modelling evaluation of Kohout geothermal convection
Authors: Caspard E. , Rudkiewicz J.‐L. , Eberli G. P. , Brosse E. , Renard M.
Published: January 2004

The hypothesis that Kohout thermal convection may have induced the massive dolomitization of the 60 m thick lowest more reefal unit in well Unda [top of Great Bahama Bank (GBB)] is evaluated through numerical modelling. A two‐dimensional (2‐D) section, including lithological and petrophysical data, together with datings for the sediments of the GBB, was used in the basin model TEMISPACK to reconstruct the history of the whole platform, with a focus on the reef unit.

Simulations showed that during high sea‐level periods, Kohout convection is a valid mechanism in the settings of the GBB, although the convection cell remains flat in most cases because of high permeability anisotropy. This mechanism induces rapid fluid flow in the superficial as well as in the deeper parts of the platform, with velocities of at least two orders of magnitude higher than with compaction alone. Lithology appears as a strong control of fluid circulations at the margin scale through the permeability anisotropy, for which a critical value lies between values of 10 and 100. The reefal unit in Unda is part of a larger area determined by the lithologic distribution, in which flow velocities are significantly higher than in the rest of the platform. These velocities are high enough to bring the magnesium necessary to precipitate the observed amounts of dolomite, within durations in agreement with the available time of post‐reef deposition high sea level(s). However, neither fluid flow pattern nor flow velocities are able to explain the preferential massive dolomitization of the lower reef unit and the complete absence of dolomite in the upper one.
Gas breakthrough experiments on pelitic rocks: comparative study with N2, CO2 and CH4
Authors: Hildenbrand A. , Schlömer S. , Krooss B. M. , Littke R.
Published: January 2004

The capillary‐sealing efficiency of intermediate‐ to low‐permeable sedimentary rocks has been investigated by N2, CO2 and CH4 breakthrough experiments on initially fully water‐saturated rocks of different lithological compositions. Differential gas pressures up to 20 MPa were imposed across samples of 10–20 mm thickness, and the decline of the differential pressures was monitored over time. Absolute (single‐phase) permeability coefficients (kabs), determined by steady‐state fluid flow tests, ranged between 10−22 and 10−15 m2. Maximum effective permeabilities to the gas phase keff(max), measured after gas breakthrough at maximum gas saturation, extended from 10−26 to 10−18 m2. Because of re‐imbibition of water into the interconnected gas‐conducting pore system, the effective permeability to the gas phase decreases with decreasing differential (capillary) pressure. At the end of the breakthrough experiments, a residual pressure difference persists, indicating the shut‐off of the gas‐conducting pore system. These pressures, referred to as the ‘minimum capillary displacement pressures’ (Pd), ranged from 0.1 up to 6.7 MPa. Correlations were established between (i) absolute and effective permeability coefficients and (ii) effective or absolute permeability and capillary displacement pressure. Results indicate systematic differences in gas breakthrough behaviour of N2, CO2 and CH4, reflecting differences in wettability and interfacial tension. Additionally, a simple dynamic model for gas leakage through a capillary seal is presented, taking into account the variation of effective permeability as a function of buoyancy pressure exerted by a gas column underneath the seal.
Use of a Wearable Defibrillator in Terminating Tachyarrhythmias in Patients at High Risk for Sudden Death:
Authors: FELDMAN ARTHUR M. , KLEIN HELMUT , TCHOU PATRICK , MURALI SRINIVAS , HALL W. JACKSON , MANCINI DONNA , BOEHMER JOHN , HARVEY MARK , HEILMAN M. STEPHEN , SZYMKIEWICZ STEVEN J. , MOSS ARTHUR J. ,   WEARIT and BIROAD investigators and coordinators
Published: January 2004

The automatic ICD improves survival in patients with a history of sudden cardiac arrest. However, some patients do not meet the guidelines for ICD implantation or are unable to receive an implantable device. This study tested the hypothesis that these patients could benefit from a wearable cardioverter defibrillator. Patients with symptomatic heart failure and an ejection fraction of <0.30 (WEARIT Study) or patients having complications associated with high risk for sudden death after a myocardial infarction or bypass surgery not receiving an ICD for up to 4 months (BIROAD Study) were enrolled into two studies. After a total of 289 patients had been enrolled in the trial (177 in WEARIT and 112 in BIROAD), prespecified safety and effectiveness guidelines had been met. Six (75%) of eight defibrillation attempts were successful. Six inappropriate shock episodes occurred during 901 months of patient use (0.67% unnecessary shocks per month of use). Twelve deaths occurred during the study 6 sudden deaths: 5 not wearing and 1 incorrectly wearing the device). Most patients tolerated the device although 68 patients quit due to comfort issues or adverse reactions.
The results of the present study suggest that a wearable defibrillator is beneficial in detecting and effectively treating ventricular tachyarrhythmias in patients at high risk for sudden death who are not clear candidates for an ICD and may be useful as a bridge to transplantation or ICD in some patients. (PACE 2004; 27:4–9)
Atrial Refractoriness and Action Potential Duration After Sudden Reversal of Atrioventricular Sequence
Authors: KETTUNEN EIJA , PARIKKA HANNU , VERKKALA KALERVO , TOIVONEN LAURI
Published: January 2004

To address the potential of atrioventricular (AV) asynchrony to provoke cardiac arrhythmias, atrial electrophysiology was examined during normal and reversed AV interval in anesthetized pigs. A new automatic stimulation technique was adapted to monitor rapid changes in the effective refractory period (ERP), using continuous AV sequential pacing, incremental extrastimulus interval scanning, and automatic detection of capture. Right atrial ERP using 2–8 ms stimulus interval increments and right atrial and ventricular monophasic action potential (MAP) duration were determined simultaneously when the AV interval was changed from normal (+80 ms) to reversed (−40 ms) and back. During reversed AV interval the peak right atrial pressure increased from 8 ± 3 to 14 ± 4 mmHg (P < 0.001) and mean arterial pressure decreased from 86 ± 18 to 65 ± 21 mmHg (P < 0.001). At new steady state, atrial ERP and MAP duration at 90% level of repolarization were lengthened by 22 ± 16 and 42 ± 12 ms respectively (P < 0.001). Ventricular MAP duration did not change. A statistically significant lengthening in atrial ERP could be demonstrated in 5–10 seconds. After reversion of the AV sequence, the ratio of atrial ERP to MAP duration decreased from 1.27 to 0.94 (P < 0.001) on average for 15 seconds, the change being thought to favor reentry. Thus atrial wall stress from contraction during ventricular systole even for a short period of time modifies atrial electrophysiology. Deficient AV synchrony may immediately contribute to the development of atrial arrhythmias. (PACE 2004; 27:10–18)
Optimal Pacing for Symptomatic AV Block:
Authors: HUANG MAX , KRAHN ANDREW D. , YEE RAYMOND , KLEIN GEORGE J. , SKANES ALLAN C.
Published: January 2004

VDD pacing provides the physiological benefits of atrioventricular synchronous pacing with the convenience of a single lead system, but is hampered by uncertainty regarding long term atrial sensing and potential development of sinus node disease. To examine the long‐term reliability and complication rates of VDD pacing, we compared the outcome of 112 consecutive patients (age 70 ± 13 years, 59% men) with symptomatic AV block who received a single pass bipolar VDD system, to 80 patients (age 63 ± 16 years, 70% men) who received DDD pacing for the same indication. All patients were judged to have intact sinus node function based on submitted ECGs and monitoring results at the time of implant. Implant time was reduced in VDD patients compared to DDD patients (63 ± 20 vs 97 ± 36 minutes, P < 0.0001). Implant complications occurred in 5 (6%) DDD patients compared to 3 (3%) VDD patients (P = 0.15). The implant P wave was lower with VDD pacing compared to DDD patients (2.91 ± 1.48 vs 4.0 ± 1.7 mv, P < 0.0001), but remained stable during long‐term follow‐up in both groups. During 17.7 ± 10.0 months of follow‐up in the VDD group, only two VDD patients were reprogrammed to VVIR mode, compared to three DDD patients. Physiological atrioventricular activation was maintained in 94%–99% of beats throughout the follow‐up period in the VDD group. VDD pacing is an excellent strategy for treatment of patients with symptomatic AV block. The lower cost, high reliability, and abbreviated implantation time suggest that VDD pacing is a viable alternative to DDD pacing in patients with high degree AV block and normal sinus node function. (PACE 2004; 27:19–23)
Effect of Autonomic Stressors on Rate Control in Pacemakers Using Ventricular Impedance Signal
Authors: Santini Massimo , Ricci Renato , Pignalberi Carlo , Biancalana Gianluca , Censi Federica , Calcagnini Giovanni , Bartolini Pietro , Barbaro Vincenzo
Published: January 2004

The aim of this study is to evaluate the heart rate adaptation obtained by a pacemaker, based on a measure of ventricular impedance in patients undergoing autonomic challenges. The evaluation procedure was based on the analysis of the mean value (MV) and heart rate variability (HRV) of RR and systolic pressure intervals, according to a set of neurovegetative stressors (controlled respiration in supine position and during active standing; mental stress; handgrip, and noninvasive sinusoidal stimulation of carotid baroreceptors). Each test lasted 5 minutes. Fifteen chronotropic incompetent patients first implanted, were studied three months after implantation. ECG, respiration activity, and noninvasive blood pressure were monitored. HRV was evaluated by spectral analysis. Variability in the low frequency (LF) and high frequency (HF) bands was compared by computing percentage and absolute powers. We found that baseline HR was 72.2 ± 5.5 beats/min, in mental stress was 76.8 ± 7.8 beats/min, in handgrip was 79.2 ± 6.3 beats/min, and in active standing was 80.9 ± 8.6 beats/min (P < 0.01, Friedman's test). During active standing, LF component was significantly higher with respect to baseline (25.7% of total power in standing; 9.4% in baseline, P < 0.01) and it was synchronous to the LF component of the arterial pressure variability. Carotid activation/deactivation by neck suction induced synchronous changes in the paced rates. In conclusion, closed loop strategy based on ventricular contractility continuously controls heart rate by tracking the sympathetic modulation to the heart. (PACE 2004; 27: 24–32)
Influence of High‐Pass Filtering on Noncontact Mapping and Ablation of Atrial Tachycardias
Authors: SCHNEIDER MICHAEL A. E. , NDREPEPA GJIN , WEBER STEFAN , DEISENHOFER ISABEL , SCHÖMIG ALBERT , SCHMITT CLAUS
Published: January 2004

The aim of the study was to define the impact of different high‐pass filter settings (HPF) on the accuracy of mapping of ectopic atrial tachycardias (EAT) using a noncontact mapping (NCM) system. In 20 patients with 22 EAT a noncontact probe was deployed in the right (n = 19) or in the left atrium (n = 3). The device enables interpolation and analysis of unipolar electrograms. It provides information on focus localization and signal morphology. These parameters were compared in different HPF of 0.5 Hz, 2 Hz, 8 Hz, and 16 Hz. The NCM signal morphology was preserved at all HPF. An initial negative deflection recorded by NCM system showed a positive predictive value of 93% regarding the ablation success. The deviation (spatial disparity) between visualized focus origin and successful ablation site was 6.9 ± 5.4 mm. Between two consecutive filter settings, the focus shift was more pronounced between 0.5 and 2 Hz (5.4 ± 4.5 mm) compared to a setting between 8 and 16 Hz (2.9 ± 2.9 mm; P < 0.05). Successful ablation was achieved in 15/18 right atrial tachycardias (83%) and in 2/3 left atrial arrhythmias. Different HPF influence NCM spatial analysis of EAT. However, a small variability in foci localization does not impact final ablation results. (PACE 2004; 27:38–46)
A Fast and Simple Echocardiographic Method of Determination of the Optimal Atrioventricular Delay in Patients After Biventricular Stimulation
Authors: Meluzín JaroslaV , Novák Miroslav , MüllerovÁ Jolana , Krejčí Jan , Hude Petr , Eisenberger Martin , Dušek Ladislav , Dvořák Ivo , ŠPinarová Lenka
Published: January 2004

The optimization of atrioventricular (AV) delay is known to signifcantly contribute to maximum cardiac performance. The aim of this study was to validate a new, fast, and simple echocardiographic method of identifying the AV delay that provides the maximum cardiac output (CO). Right heart catheterization and Doppler echocardiography of transmitral filling were performed simultaneously in 18 patients with heart failure and at least minimum functional mitral regurgitation treated with atrial synchronized biventricular pacing. CO derived from catheterization and Doppler filling parameters were measured at the predicted optimal AV delay (oAVD), the short AV delay (oAVD − 50 ms), and the long AV delay (oAVD + 28 ms on average/range, +10 ms to +50 ms) during a constant heart rate. The AV delay was regarded as optimal if the end of atrial contraction (represented by the end of A wave of transmitral filling) coincided with the beginning of ventricular contraction (heralded by the onset of the systolic component of mitral regurgitation). Prediction of the optimal AV delay included the following steps: (1) The maximum AV delay at which full ventricular capture is still preserved was found under electrocardiographic control. (2) This value, decreased by 5 to 10 ms, was designated as “the testing long AV delay,” and the time interval from the end of the A wave to the onset of the systolic component of mitral regurgitation (time t1) was measured at this setting. (3) oAVD was simply calculated as “the testing long AV delay”− time t1. The CO measured at the oAVD (4.5 ± 0.7 1 · min−1) significantly exceeded those at the short AV delay (4.3 ± 0.7 1 · min−1, P < 0.01) and the long AV delay (4.4 ± 0.8 1 · min−1, P < 0.01), respectively. The method correctly determined the maximum CO in 78% of the patients. In conclusion, Doppler echocardiography enables very rapid and accurate optimization of AV synchrony in patients after the implantation of a biventricular pacemaker. (PACE 2004; 27:58–64)
Combined Therapy with Steroids and Antioxidants Prevents Ultrastructural Damage Surrounding Chronic Radiofrequency Lesions
Authors: FENELON GUILHERME , FRANCO MARCELLO , MORA OSWALDO , KATCHBURIAN EDUARDO , De PAOLA ANGELO A. V.
Published: January 2004

We evaluated the effects of combined therapy with anti‐inflammatory and antioxidant drugs on the healing of radiofrequency (RF) lesions (70°C, 60 s) produced in the right atrium and each ventricle of 21 adult dogs. Three groups were studied: acute (n= 7, sacrificed 1 hour after RF); control (n = 7, sacrificed 54 ± 29 days after RF); and dogs (n = 7, sacrificed 32 ± 5 days after RF) receiving combined therapy with allopurinol (400 mg po 24 and 2 hours before RF); verapamil (200 μg/kg IV 15 min before and after RF); hydrocortisone (10 mg/kg IV after RF) and prednisone (20 mg po for 29 days). Atrial (n = 37) and ventricular (n = 70) lesion dimensions were determined and 21 right ventricular apex lesions (1 per dog) were selected for light and electron microscopy analysis. Histological and ultrastructural (US) characteristics in three zones extending from the visible lesion border, A (0–3 mm); B (3–6 mm); and C (6–9 mm), were assessed. In chronic groups, atrial and ventricular lesion dimensions were similar, but delayed scar formation was noted in treated animals. Acutely and at follow‐up, significant US abnormalities occurred in zones A and B and chronic lesions exhibited type I collagen proliferation. In Zone A, the extent of US injury and collagen proliferation was significantly less in treated dogs. Further, Zone B was normal in 5/7 (71%) treated dogs and in 0/7 (0%) controls. Zone C was essentially normal in all groups. Combined therapy with steroids, verapamil, and allopurinol is effective in limiting US damage surrounding chronic RF lesions. (PACE 2004; 27:65–72)
Familial Atrioventricular Nodal Reentry Tachycardia
Authors: Hayes John J. , Sharma Param P. , Smith Peter N. , Vidaillet Humberto J.
Published: January 2004

Dual atrioventricular nodal pathways, the substrate responsible for atrioventricular node reentry tachycardia (AVNRT), are thought to be randomly occurring congenital anomalies. This article describes 14 patients in six families, each with two or three first‐degree relatives with paroxysmal supraventricular tachycardia. Electrophysiological evidence of dual atrioventricular nodal pathways was established in all 13 patients studied, AVNRT was induced in 12 (92%), and radiofrequency ablation of the slow pathway was curative in all cases. The data suggest a hereditary contribution to the development of atrioventricular nodal pathways and AVNRT. The pattern of inheritance appears to be autosomal dominant. (PACE 2004; 27:73–76)
Mechanism of Immediate Recurrences of Atrial Fibrillation After Restoration of Sinus Rhythm
Authors: CHUGH AMAN , OZAYDIN MEHMET , SCHARF CHRISTOPH , LAI STEVE W.K. , HALL BURR , CHEUNG PETER , PELOSI FRANK , KNIGHT BRADLEY P. , MORADY FRED , ORAL HAKAN
Published: January 2004

An immediate recurrence of AF may occur after restoration of sinus rhythm. Although pulmonary vein (PV) isolation has been shown to prevent immediate recurrence of AF, the specific trigger for immediate recurrence of AF has not been described. In 89 consecutive patients (mean age 53 ± 11 years) who had sinus rhythm restored by spontaneous or transthoracic cardioversion in the course of a PV isolation procedure, electrograms recorded within a PV and in the adjacent left atrium were analyzed to determine the mechanism of initiation of immediate recurrence of AF. Immediate recurrence of AF was defined as a recurrence of AF within 90 seconds after restoration of sinus rhythm. There were 124 episodes of immediate recurrence of AF at a mean of 18 ± 23 seconds after cardioversion. Recordings within the PV that triggered the immediate recurrence of AF were available in 23 (19%) of the 124 immediate recurrence of AF episodes. Among these 23 episodes of immediate recurrence of AF, all (100%) were triggered by a burst of PV tachycardia (P < 0.001). The coupling interval and prematurity index (coupling interval/preceding sinus cycle length) of the premature depolarizations that did and did not trigger immediate recurrence of AF were 246 ± 67 ms and 0.30 ± 0.11 vs 378 ± 117 ms and 0.49 ± 0.16, respectively (P < 0.01). Immediate recurrence of AF was abolished by PV isolation. The mechanism of immediate recurrence of AF is a burst of PV tachycardia, not a single premature depolarization. Immediate recurrence of AF identifies patients with AF in whom the PVs may play a major role in the initiation of AF. (PACE 2004; 27:77–82)