bluuebunny/crossref_metadata_2025_split huggingface dataset:
Torsade de Pointes and Sudden Death Induced by Thiopental and Isoflurane Anesthesia in Dogs with Cardiac Electrical Remodeling
Authors: Zhou Shengmei , Cao Ji-Min , Ohara Toshihiko , KenKnight Bruce H. , Chen Lan S. , Karagueuzian Hrayr S. , Chen Peng-Sheng 
Published: June 2007

Background: Many anesthetic agents are known to have cardiac effects. The effects of pentobarbital, thiopental and isoflurane on dogs with electrical remodeling are lacking. Methods and Results: We studied 12 dogs that underwent two anesthesias. First, anesthesia was induced (N=12) with intravenous thiopental (17 mg/kg) induction followed by isoflurane inhalation (1.5%-3% via endotracheal tube). For electrical remodeling, we created complete atrioventricular block (CAVB) and myocardial infarction (MI). In 6 of the 12 dogs we also infused nerve growth factor (NGF) to the right stellate ganglion. All dogs had an implantable cardioverter-defibrillator (ICD) implanted. A second anesthesia was done 66 ± 20 days later. In 8 of the 12 dogs (6 without NGF), pentobarbital was used as the only anesthetic. In the remaining 4 dogs (all with NGF), 3 received thiopental and 1 received isoflurane. Results: During the first anesthesia, none of 12 dogs had cardiac arrhythmia. During the second anesthesia, none of the 8 dogs that received pentobarbital developed ventricular fibrillation (VF). In contrast, all the dogs receiving either thiopental or isoflurane died of VF within 2 to 3 minutes. QT and P-P intervals before VF were 440 ± 36 milliseconds and 298 ± 28 milliseconds, longer and shorter (respectively) than those obtained the day prior to surgery (315 ± 25 milliseconds, P < 0.001; 330 ± 22 milliseconds, P < 0.01, respectively). Conclusion: Thiopental and isoflurane are not arrhythmogenic in normal dogs and dogs with acute MI and CAVB, but are extremely proarrhythmic in dogs with chronic MI and CAVB. Consistent with the results of in vitro studies, pentobarbital did not induce ventricular arrhythmia in dogs with cardiac electrical remodeling.
Pharmacologic Reversion of Persistent Atrial Fibrillation with Amiodarone Predicts Long-Term Sinus Rhythm Maintenance
Authors: Galperín Jorge , Elizari Marcelo V. , Chiale Pablo A. , Molina Remberto Torres , Ledesma Raúl , Scapín Angel O. , Blanco Manuel Vázquez , Bonato Ricardo , Lago Manuel ,   Grupo de Estudio de Fibrilación Auricular Con Amiodarona (GEFACA) Investigators
Published: June 2007

Objective: The study analyzed the role of differentvariables that determine long-term sinus rhythm maintenance inpatients with persistent atrial fibrillation who are treated withamiodarone. Background: It has been recognized that different factors influence long-term sinus rhythm preservation after the conversion of persistent atrial fibrillation. Although the duration of the arrhythmia appears to be the most important factor, consistent information regarding the role of the mode of arrhythmia conversion (pharmacologic or electric) is still lacking. Methods: One hundred and forty one anticoagulated patients with persistent atrial fibrillation (median duration 8 months, percentiles 25 and 75: 2-24) were treated for 4 weeks with oral amiodarone (600 mg/day). Those in whom the arrhythmia persisted underwent electric cardioversion. After restoration of normal sinus rhythm (either pharmacologic or electric), all patients received a daily dose of amiodarone (200 mg) and were followed for a median of 19 months (percentiles 25 and 75: 8-34 months). Results: Sixty eight patients (48.22%) regained sinus rhythm during the initial period of amiodarone treatment with 600 mg/day (Group I) and 73 (51.78%) required electric cardioversion (Group II). During the entire follow-up, atrial fibrillation relapsed in 63 patients: 17 (25%) in Group I and 46 (63%) in Group II. Recurrences of the arrhythmia were strikingly less frequent in patients whose atrial fibrillation lasted 12 months or less (33/103, 32.3%) than in those whose atrial fibrillation lasted more than 12 months (30/38, 78.94%). In the multivariate analysis, the mode of reversion (HR, 0.37; CI, 0.21-0.65) and the duration of the arrhythmia (HR, 2.55; CI, 1.54-4.20) were the determinants for long-term sinus rhythm maintenance. Age, sex, left atrium size, left ventricle diameter, and the shortening fraction did not significantly influence the rate of arrhythmia recurrence. Among the 141 patients included in the study, 113 patients were followed for at least 1 year, and cardiac rhythm was assessed at this time. Of these, only 1 of 48 patients (2.1%) in Group I was in atrial fibrillation, in marked contrast with 18 of 65 patients (27.8%) in Group II (RR, 0.075; 95% CI, 0.01-0.54). Conclusions: In patients with persistent atrial fibrillation, long-term preservation of sinus rhythm under chronic amiodarone treatment may be anticipated when the arrhythmia lasts 12 months or less and/or its reversion is obtained pharmacologically. We may confidently assume that these two factors have a beneficial additive influence on the outcome.
Amiodarone Rescue Therapy for Severe Decompensated Heart Failure Initially Unsuitable for β-Blockers
Authors: Choo Daniel C. , Huiskes Bonnie , Jones Jennifer , Fabbri Sharon , Hawkins Lee Ann , Chatterjee Kanu , De Marco Theresa , Heywood J. Thomas 
Published: June 2007

Background: β-Blocker therapy is now standard therapy for patients with stable heart failure; however, fluid-overloaded, New York Heart Association Class IV patients tolerate β-blockers poorly. Amiodarone, a drug with antiadrenergic effects, has been shown to improve survival for patients with heart rates of 90 beats per minute or greater. Methods: We reviewed 26 patients with severe decompensated heart failure who were started on oral amiodarone for heart rate control. β-Blocker titration was attempted when patients became clinically stable. Results: The mean age of the patients was 48.5±17.5 years, and 73% were male. Fifteen patients were New York Heart Association Class IV, and 11 were Class III. Of these, 23 (88%) were fluid-overloaded, and 11 (42%) were on inotropic agents when amiodarone was started. The mean ejection fraction was 16.1 ± 6%. The initial dose of amiodarone was 346 ± 120 mg/day. Twenty (77%) patients were successfully started on β-blockers. At follow-up prior to β-blockers, 20 (77%) patients improved by at least one New York Heart Association class. Heart rate decreased from a mean of 98 ± 15 to 78 ± 13 beats per minute (P < .0001). Echocardiograms were available in 12 patients, with ejection fractions increasing from 16.1 ± 8% to 26.8 ± 13% (P= .004). Conclusions: Amiodarone may be an effective rescue therapy for patients with decompensated heart failure and serve as a bridge to subsequent β-blocker therapy.
Upregulation of Angiotensin II Type 2 Receptor and Limitation of Myocardial Stunning by Angiotensin II Type 1 Receptor Blockers during Reperfused Myocardial Infarction in the Rat
Authors: Jugdutt Bodh I. , Menon Vijayan 
Published: June 2007

Background: We have previously shown that angiotensin II type 1 receptor blockers induce cardioprotection and upregulate angiotensin II type 2 receptor during in vivo postischemicreperfusion in dogs. Whether angiotensin II type 1 receptor blockers upregulate angiotensin II type 2 receptors in rats is controversial, and whether surmountable and insurmountable angiotensin II type 1 receptor blockers exert similar protective effects during reperfused myocardial infarction is not known. Methods: We assessed the effects of the surmountable angiotensin receptor blocker valsartan, and the insurmountable angiotensin receptor blocker irbesartan, on hemodynamics and left ventricular systolic and diastolic function (echocardiography/Doppler) in vivo and infarct size (triphenyl tetrazolium chloride method), and regional angiotensin II type 1 receptor and angiotensin II type 2 receptor expression (immunoblots) ex vivo, after anterior reperfused myocardial infarction in rats. The rats were randomized to four groups: intravenous valsartan (10 mg/kg, n = 8), irbesartan (10 mg/kg, n = 8), or saline vehicle (controls, n = 14) over 30 minutes before reperfused myocardial infarction, and sham (n = 8). Angiotensin II type 1 receptor blockade was assessed by the inhibition of angiotensin II pressor responses. Results: Compared with the control group, both angiotensin receptor blockers significantly decreased infarct size, limited the increase in left atrial pressure, improved positive left ventricular dP/dtm,x and dP/dtm,,, improved left ventricular ejection fraction and diastolic function, and limited infarct expansion after reperfused myocardial infarction. Both angiotensin receptor blockers increased angiotensin II type 2 receptor protein in the postischemic-reperfused zone, with no change in angiotensin II type 1 receptor protein. There were no changes in the sham group. Conclusion: The overall results indicate that the angiotensin receptor blockers valsartan and irbesartan both induce cardioprotection, limit myocardial stunning, and upregulate angiotensin II type 2 receptor protein expression after reperfused myocardial infarction in the rat. Patients who are already receiving angiotensin receptor blockers and develop acute coronary syndromes might benefit from these cardioprotective effects during reperfusion therapy.
Effect of Angiotensin II lype 2 Receptor Blockade on Activation of Mitogen-Activated Protein Kinases after Ischemia-Reperfusion in Isolated Working Rat Hearts
Authors: Kumar Dinender , Menon Vijayan , Ford William R. , Clanachan Alexander S. , Jugdutt Bodh I. 
Published: June 2007

Background: The stress-responsive mitogen-activated protein kinases (MAPKs) (p38-MAPK, c-Jun NH2-terminal kinase [JNK-1 and JNK-2], and extracellular signal regulated kinases [ERK-1 and ERK-2]) might be involved in angiotensin II (AIJ)-induced ischemiareperfusion injury. Cardioprotection induced by All type 1 (AT1) and type 2 (AT2) receptor blockade during ischemia-reperfusion is associated with protein kinase Cc (PKCe), nitric oxide, and cyclic guanosine monophosphate (cGMP) signaling. Our aim was to assess the effect of selective AT, and AT2receptor blockade with losartan and PD123,319, respectively, on MAPK expression after ischemia-reperfusion in isolated working rat hearts.Methods: Groups of six hearts were subjected to global ischemia (30 minutes) followed by reperfusion (30 minutes) and exposed to no drug/no ischemia-reperfusion (control), ischemia-reperfusionlno drug, and ischemia-reperfusion with losartan (1 MM), or PD123,319 (0.3,uM) and additional groups. AT,/AT2receptor expression, MAPKs, PKCE, and cGMP, and changes in mechanical function were measured. Western blotting was done on left ventricular tissue for AT,/AT2, p38/phosphorylated-p38 (p-p38), phosphorylated (p)-JNK-1/-2, phosphorylated (p)-ERK-1/-2, and PKCe proteins; Northern blots for AT,/AT2mRNA; and enzyme immunoassay for cGMP.Results: Compared with controls, ischemia-reperfusion induced significant left ventricular dysfunction, decreased AT2protein and mRNA, increased p-p38 and p-JNK-1/-2, did not change p-ERK-1/-2 or PKCe, and decreased cGMP. PD123,319 improved left ventricular recovery after ischemia-reperfusion, increased AT2protein and mRNA, mildly increased p-p38, normalized p-JNK-1, did not change p-ERK-1/-2, and increased PKCe and cGMP. Losartan did not change p-p38, increased p-JNK-1, and did not change pERK- 1/-2, PKCe, or cGMP.Conclusions: The overall results suggest that the activation of p38-MAPK and JNK might be linked to All signaling and play a significant role in acute ischemia-reperfusion injury as well as in the cardioprotective effect of AT2receptor blockade.
Left Ventricular Performance During Acute Rate Control in Atrial Fibrillation: The Importance of Heart Rate and Agent Used
Authors: Pinter Arnold , Dorian Paul , Paquette Miney , Ng Alvina , Burns Mark , Spanu Ileana , Freeman Michael , Korley Victoria , Newman David 
Published: June 2007

Background: The relation between heart rate and left ventricular function during rate control in atrial fibrillation is incompletely understood. Methods: Twenty-four patients (age 67 ± 11 years) with symptomatic recent onset rapid atrial fibrillation and rapid ventricular rate (> 110 bpm) were randomly assigned to receive either intravenous digoxin (13 mcg/kg) or intravenous diltiazem (0.25 mg/kg bolus plus a maintenance infusion). A portable radionuclide detector was used to collect validated measures of relative left ventricular volumes, along with heart rate data, every 15 seconds for 6 hours. Results: Heart rate decreased significantly at 15 minutes and 180 minutes in the diltiazem group (from 133 ± 18 bpm to 111 ± 26 bpm [P < .01] to 94 ± 24 bpm [P < .001]) but not in the digoxin group (from 129 ± 18 bpm to 126 ± 17 bpm [P = NS] to 118 ± 15 bpm [P = NS]). Left ventricular ejection fraction improved in both groups to a similar extent (from 39 ± 10% to 50 ± 8%, [P < .05] after diltiazem, and from 38 ± 8% to 52 ± 11% [P < .05] after digoxin at baseline vs 180 minutes, respectively). The ejection fraction vs heart rate slope was steeper in the digoxin group than in the diltiazem group (-0.34 ± 0.18 vs -0.16 ± 0.17, P = .048) indicating a more pronounced improvement in ejection fraction per unit decrease in heart rate. Conclusion: In patients with acute atrial fibrillation, digoxin led to similar improvements in ejection fraction compared to diltiazem despite a slower and less potent heart rate slowing.
Dual Roles of 5-Hydroxytryptamine in Ischemia-Reperfusion Injury in Isolated Rat Hearts
Authors: Takano Shizuko , Hoshino Yuji , Li Libing , Matsuoka Isao , Ono Tomoyuki , Kimura Junko 
Published: June 2007

Background: 5-Hydroxytryptamine (5-HT) has been shown to be involved in exacerbating cardiac ischemia-reperfusion injury; however, the role of 5-HT in the injury has yet to be established. This study demonstrates that 5-HT has dual roles in ischemia-reperfusion injury. Methods and Results: The role of 5-HT in cardiac ischemia-reperfusion injury was examined in isolated rat hearts perfused with oxygenated Krebs-Henseleit solution. A 30-minute global ischemia and 30-minute reperfusion exacerbated functional cardiac parameters such as left ventricular end-diastolic pressure, coronary flow, heart rate, and total lactate dehydrogenase release. The 5-HT2A receptor antagonist sarpogrelate (0.3-1.0 μM) improved cardiac function during ischemia-reperfusion. High-performance liquid chromatography analysis revealed an elevation in the level of 5-HT in the coronary effluent immediately after ischemia, suggesting that 5-HT is released from the ischemic heart and that sarpogrelate protects the heart from ischemia-reperfusion injury by blocking 5-HT2A receptors. However, 5-HT (0.3-1.0,μM) applied exogenously unexpectedly improved the cardiac mechanical parameters during ischemia-reperfusion, increased coronary flow, and increased the level of NO in the effluent, which was inhibited by L-NG-nitro-arginine methyl ester, a NO synthase blocker. Conclusions: Present results suggest dual roles of 5-HT in ischemia-reperfusion injury. During ischemia, 5HT is released endogenously, constricts coronary smooth muscles via 5-HT2A receptors, and aggravates cardiac function. In contrast, 5-HT applied exogenously affects predominantly non-5HT2A receptors on the endothelium and induces coronary vasodilatation via endothelial NO production, which is protective against ischemia-reperfusion injury.
A cognitive tool to diagnose predominantly inattentive ADHD behavior
Authors: Aaron P. G. , Joshi R. M. , Phipps Jill 
Published: June 2007

Poor performance on tests of reading comprehension could be the result of weak word-recognition skills, inconsistent attention (ADD), or a combination of the two. Identifying the source of the reading disability (RD) reliably has been difficult because inconsistent attention interferes with reading and weak word recognition skill makes attention wander. The situation is further complicated by the fact that there are no objective diagnostic tests for ADD (Breggin, 1998; Diller, 1998). We proposed a new model of differential diagnosis of ADHD-I/RD and field-tested its utility in two studies. The new diagnostic procedure utilizes intra-individual differences seen in the performance of at-risk learners on tasks related to reading that vary in the degree of sustained attention required for successful performance. The hypothesis is that children whose attention is inconsistent would perform more poorly on tests such as listening comprehension, which require sustained attention, than on tests such as reading comprehension, which are more tolerant of inattention. Such differences will not be seen in the test scores of children who have only a reading disability because their performance on reading tests is determined more by the difficulty level of the tests than by the sensitivity of the tests to attention. The validity of this new model was evaluated by determining the relationship between differences seen in the scores of tests that differ in their attention requirement and the degree of inconsistency in sustained attention as measured by Conners’ CPT. The results of the two studies indicate this to be a viable approach. The results of the second study are presented in this report.
Emotional reactivity in children with Attention-Deficit/Hyperactivity Disorder
Authors: Jensen S. A. , Rosén L. A. 
Published: June 2007

Objective: This study examined Barkley’s (1997b) theory regarding the emotional regulation of children with Attention-Deficit/Hyperactivity Disorder (ADHD). Method: Mothers of children with and without ADHD between the ages of 6 and 15 were asked to rate their child’s emotional response on each of three measures. Results: Children with ADHD were rated as significantly more emotionally reactive to both immediate and future events than were children without ADHD. Differences at both the immediate and future time periods were stronger in response to negative as opposed to positive emotional events. In response to the consequences of their behavior, however, children with ADHD were rated as less emotionally reactive than children without ADHD. Discussion: Conclusions are made in reference to Barkley’s theory and implications are explored.
Repositioning travel agencies on the Internet
Authors: Barnett Martin , Standing Craig 
Published: June 2007

Traditionally, retail travel agencies have acted as intermediaries between primary creators/suppliers of travel products and the consumer, largely as a function of taking upon themselves the transaction costs for the consumer to find and select appropriate travel facilitators. Internet-related technologies dramatically change transaction costs in communication-based activities and raise both challenges and opportunities for this business sector relating to issues of the nature and value of intermediation. Two major threats currently perceived are the disintermediation of retail agencies by primary producers, and the emergence of new virtual intermediaries. The potential for structural changes in the travel sector highlights the need for travel agencies to actively select between business models which can best support an effective online strategy. The lowering cost of information and communications technology calls into question the sustainability of many existing implicit online models. To aid in the creation of new forms, we use the series of seven models derived by Burn and Barnett1 to describe the range of virtual organisational structures and apply these in the travel industry. The value of each of these forms lies in there being an appropriate response to the communication and transaction needs within a given nexus of market forces and opportunities. It is argued that the characteristics of traditional travel agencies are not yet aligned with the demands of the new travel economy. A rapidly changing business environment, largely brought about by the Internet, will require companies to quickly develop new affiliations and alliances, have access to new products and be creative in their marketing. It is suggested that an awareness of the range of organisational forms, together with an appreciation of their potential for application, will aid successful adaptation by travel companies within a changing business environment.
The Canadian air transport industry: In crisis or in transition?
Authors: Archambault Michel , Roy Jacques 
Published: June 2007

The air transport industry is currently experiencing one of the most difficult periods in its history. According to the International Air Transport Association (IATA), the global airline industry lost more than US$10bn in 2001. In Europe, well-established carriers such as Sabena and Swissair have had to declare bankruptcy after decades of existence. In Canada, the dominant carrier, Air Canada, declared a record loss of C$1.25bn in 2001. It is tempting to attribute all these problems to the economic slowdown that began in early 2001 and was exacerbated by the tragic events of 11th September, 2001. After all, global air traffic dropped approximately 4 per cent in 2001. However, low-fare carriers are still earning profits and growing at a rate that is the envy of traditional scheduled carriers. In short, one question arises: are the industry’s current problems the result of a temporary economic downturn, or are they the outcome of a major transformation that began several years ago? This is the question addressed in this paper by examining recent changes in the Canadian air transport industry.
Communicating in a crisis: The British Tourist Authority’s responses to the foot-and-mouth outbreak and 11th September, 2001
Authors: Frisby Elliott 
Published: June 2007

The tourism industry makes a significant contribution to the UK’s economy. Inbound tourism by visitors from overseas to Britain was badly disrupted in 2001 by the combined effects of the foot-and-mouth outbreak and the impact of 11th September on global travel trends. The British Tourist Authority (BTA), which promotes Britain as a destination in 27 markets overseas, developed a strategy to make use of additional government funding to boost visitor spending in Britain in 2002 and beyond. This paper explores the impact of the events of 2001 on Britain’s inbound tourism industry and provides an insight into the initiatives undertaken by the BTA on behalf of the industry.
Clinical governance: The route to (modern, dependable) nursing research?
Authors: Boden Louise , Kelly Daniel 
Published: June 2007

The opportunities offered by clinical governance are explored by a chief nurse and director of quality and a senior nurse (R&D) working in an inner-city NHS trust at a time of considerable change and uncertainty. The paper offers an insight into each of our perspectives on clinical governance-the latest concept behind recent health reforms in the UK-and contributes to the debate on the subject by suggesting the adoption of a strategic approach to encourage nursing research that is more related to practice. First, clinical governance is defined, following which its component elements-clinical effectiveness, education and training, quality monitoring and cost control in healthcare-are explored in relation to the general concept of clinical governance. Examples of key initiatives, based on our recent experience at this NHS trust, are provided to examine how the various strands of the clinical governance framework (such as risk management) have the potential to benefit patients by their focus on improving the standard of healthcare being provided. Questions are then raised about the place of nursing research within the wider NHS R&D agenda. We suggest that the adoption of clinical governance will offer a unique opportunity for nursing leaders, researchers and practice developers to work together to help shape the future culture of healthcare, particularly at the point of clinical delivery. If such an opportunity is to be maximised, a number of fundamental issues must be addressed with urgency. These include ensuring that successful initiatives are identified and implemented to demonstrate the contribution that nursing research can make to tangible healthcare improvements.