bluuebunny/crossref_metadata_2025 huggingface dataset:
Educating Children with Learning Disabilities in Africa
Authors: Abosi Okey
Published: July 2007

The increase in the number of slow learners and children with learning disabilities in schools in Africa has become a major issue and concern. The situation is reflected in various school–leaving examinations, where an average of 30 percent of the results are below average or failures each year. Although there are no statistical records available in most African countries on the number of children and youth with learning disabilities, it is believed that about 8 percent of the students in school are experiencing learning difficulties in the classroom. Diverse factors contribute to the large number of school difficulties, including overcrowded classrooms, poverty, health issues, shortages of experienced teachers, traditional beliefs, lack of teaching materials, school expectations, and motivational issues. I examine the state of education for students with learning difficulties in Africa, focusing especially on Botswana but also including information from other countries, and consider the concept, prevalence, causes, provision of services, and difficulties in providing effective services for children with learning disabilities.
Students with Learning Disabilities: An Update on Norwegian Educational Policy, Practice, and Research
Authors: Thygesen Ragnar
Published: July 2007

A politically initiated shift in the conceptualization of learning disabilities (LD) is outlined, followed by an account of the consequences of the new perspective for the recognition of and services to LD students. The organization of the support system is described, including a survey of the services delivered and working methods. As another approach to examining the status of LD in Norway, a sampling of current research describes problems studied, methods of assessment, and intervention measures used. Some comments on the future situation for students with LD conclude the article.
Learning Disabilities in Guatemala and Spain: A Cross–National Study of the Prevalence and Cognitive Processes Associated with Reading and Spelling Disabilities
Authors: Jiménez Juan E. , García de la Cadena Claudia
Published: July 2007

The main purposes of this research were twofold. We examined the samenesses about learning disabilities (LD) in Guatemala and Spain, two countries with the same language but cultural, political, and educational differences, first analyzing data about the prevalence of reading and spelling disabilities in Guatemala City and the Spanish region of the Canary Islands. The focus of the second study was to determine whether there are cross–national patterns of significant differences in cognitive processes associated with reading and spelling disabilities from a developmental approach in these two cultural contexts. We found some differences in the prevalence of specific LD in reading between both countries but we did not find significant differences between Guatemalan and Spanish reading–disabled children in cognitive processes that are involved in reading and spelling acquisition in spite of the cultural and educational differences between the two countries.
International Approaches to Learning Disabilities: More Alike or More Different?
Authors: Sideridis Georgios D.
Published: July 2007

This special issue deals with the identification and remediation criteria/practices employed in several countries regarding learning disabilities (LD). An analysis of the identification criteria suggests that most countries follow early law mandates of the United States (e.g., PL 94–142) regarding the definition of the disorder and use the classical discrepancy between potential and achievement model for identification purposes (with few exceptions). Several countries reported the absence of standardized assessments and experts who can deal with the disorder, a fact that is more prominent in countries that have to deal with the education of minority/immigrant groups. Multicultural, political, linguistic, and economic factors seemed to influence both the identification practices and also the remediation services (quality and availability). By closely examining the factors deemed important for students with LD, it was obvious that most authors pointed to the importance of socio–emotional variables. I concluded that these latter factors may be accountable, to a large extent, for the experience of students with LD at school and close attention needs to be paid to them.
The Right Ventricular Outflow Tract: A Comparative Study of Septal, Anterior Wall, and Free Wall Pacing
Authors: HILLOCK RICHARD J. , STEVENSON IRENE H. , MOND HARRY G.
Published: July 2007

Background: There is marked heterogeneity in right ventricular outflow tract (RVOT) pacemaker lead placement using conventional leads. As a result, we have sought to identify a reproducible way of placing a ventricular lead onto the RVOT septum.

Methods and Results: A major determinant is the shape of the stylet used to deliver the active‐fixation lead. We compared stylet shapes and configurations in patients who initially had a ventricular lead placed onto the anterior or free wall of the RVOT and then had the lead repositioned onto the septum. All leads were loaded with a stylet fashioned with a distal primary curve to facilitate delivery of the lead to the pulmonary artery, then using a pullback technique the lead was retracted to the RVOT. All lead placements were confirmed by fluoroscopy and electrocardiography. Anterior or free wall placement was achieved by the stylet having either the standard curve or an added distal anterior angulation. In contrast, septal lead positioning was uniformly achieved by a distal posterior angulation of the curved stylet. This difference in tip shape was highly predictive for septal placement (P < 0.001). With septal pacing, a narrower QRS duration was noted, compared to anterior or free wall pacing (136 vs 155 ms, P < 0.001). All pacing parameters were within acceptable limits.

Conclusion: Using appropriately shaped stylets, pacing leads can now be placed into specific positions within the RVOT and in particular septal pacing can be reliably and reproducibly achieved. This is an important step in the standardization of lead placement in the RVOT.
The Innominate Vein as Alternative Venous Access for Complicated Implantable Cardioverter Defibrillator Revisions
Authors: ALEKSIC IVAN , KOTTENBERG‐ASSENMACHER EVA , KIENBAUM PETER , SZABO ANDRAS K. , SOMMER SEBASTIAN‐PATRICK , WIENEKE HEINER , YILDIRIM CAGATAY , LEYH RAINER G.
Published: July 2007

Background: Venous complications of implantable cardioverter defibrillator (ICD) systems may cause significant problems when the need for system revision or upgrades arises. Such revisions require venous access close to the site of the previous ICD implantation. The internal and external jugular vein have disadvantages due to a long subcutaneous course crossing the clavicle and problems with lead extraction if infection occurs.

Methods: In seven patients with ICD revisions due to lead dysfunction (n = 4) and upgrade to a biventricular device (n = 2) and status after system removal due to infection with new device implantation (n = 1) conventional venous access could not be obtained. Intraoperative contrast venography demonstrated an occluded left subclavian and/or left innominate vein in all patients. In all patients, we gained venous access through puncture of the right innominate vein and tunneled the new lead subcutaneously to the ICD pocket on the left.

Results: No intraoperative complications were observed. All patients are followed in our ICD clinic. Mean follow‐up is 16 ± 4 months now. So far, no clinical or lead complications with this access have been observed.

Conclusions: We have demonstrated that ICD lead placement through puncture of the right innominate vein is feasible. We propose the innominate vein as an alternative route for establishing venous access in patients requiring ICD revisions or upgrades who suffer from venous obstruction. ICD implanting physicians should acquaint themselves with the technique of right innominate vein puncture to use this vein as a bail‐out strategy in patients with complicated venous access.
Duration of P‐Wave Is Associated with Atrial Fibrillation Hospitalizations in Patients with Atrial Fibrillation and Paced for Bradycardia
Authors: PADELETTI LUIGI , SANTINI MASSIMO , BORIANI GIUSEPPE , BOTTO GIANLUCA , RICCI RENATO , SPAMPINATO ANDREA , VERGARA GIUSEPPE , RAHUE WERNER G , CAPUCCI ALESSANDRO , GULIZIA MICHELE , PIERAGNOLI PAOLO , GRAMMATICO ANDREA , PLATONOV PYOTR , BAROLD S. SERGE
Published: July 2007

Background: Atrial fibrillation (AF) is a common problem in pacemaker patients. We conducted a prospective observational study in patients paced for bradycardia with associated paroxysmal or persistent AF, to determine whether P‐wave duration may stratify patients at higher risk for AF recurrences and AF‐related hospitalizations. The patients were evaluated for the prevalence, cause, and predictors of hospitalization.

Methods: We studied 660 consecutive patients (50% male, 72 ± 9 years) who received a dual‐chamber pacemaker. Median value of baseline P‐wave duration was equal to 100 ms (25%–75% quartile range equal to 80–120 ms). We used this cut‐off to divide the patients into group A (P ≤ 100 ms), composed of 385 (58.3%) patients, and group B (P>100 ms), composed of 275 (41.7%) patients.

Results: In a median follow‐up of 19 months, 173 patients were hospitalized for all causes, 130 for cardiovascular causes, and 85 for AF‐related hospitalizations. Multivariate logistic analysis showed that P‐wave duration >100 ms identified patients at higher risk (OR = 1.6, 95% confidence interval (1.1–2.8), P = 0.044) for AF‐related hospitalizations. Patients in group B (P > 100 ms) more frequently suffered AF‐related hospitalizations (16.4% vs 10.4%, P = 0.02) and underwent more frequent cardioversions (14.5% vs 9.1%, P = 0.029) compared with group A (P ≤ 100 ms).

Conclusions: P‐wave duration may define the risk of persistent AF requiring cardioversion or AF‐related hospitalization in patients with a pacemaker for bradycardia with associated paroxysmal or persistent AF.
Predictors of a Positive Response to Biventricular Pacing in Patients with Severe Heart Failure and Ventricular Conduction Delay
Authors: YEIM SUNTHARETH , BORDACHAR PIERRE , REUTER SYLVAIN , LABORDERIE JULIEN , O'NEILL MARK D. , LAFITTE STEPHANE , DEPLAGNE ANTOINE , GARRIGUE STEPHANE , ROUDAUT RAYMOND , JAIS PIERRE , HAISSAGUERRE MICHEL , DOSSANTOS PIERRE , CLEMENTY JACQUES
Published: July 2007

Background: Cardiac resynchronization therapy (CRT) is recommended in patients with ejection fraction <35%, QRS width> 120 ms, and New York Heart Association (NYHA) functional class III or IV despite optimal medical therapy. We aimed to define demographic, clinical, and electrocardiographic predictors of positive clinical response to CRT.

Methods and Results: Hundred consecutive patients fulfilling the recommended criteria were implanted with a CRT device. Demographic, clinical, two‐dimensional echocardiographic and electrographic parameters were measured at baseline and after 6 months of simultaneous biventricular pacing. A positive response to CRT included an improvement of at least one NYHA functional class associated with an absence of hospitalization for worsening heart failure. At the end of follow‐up, 12 patients were dead and 71% of the patients were classified as responders. After 6 months of CRT, the ejection fraction was significantly higher (P = 0.035) in responders versus nonresponders. Multivariate analysis identified three independent predictors of positive response to CRT: an idiopathic origin of the cardiomyopathy (P = 0.043), a wider QRS before implantation (P = 0.017), and a narrowing of the QRS after implantation (P = 0.037).

Conclusion: An idiopathic origin of the cardiomyopathy, a wider QRS before implantation, and a narrowing of the QRS width after implantation were identified as independent predictors of clinical positive response to CRT.
Heart Rate Changes during Acute Mental Stress with Closed Loop Stimulation: Report on Two Single‐Blinded, Pacemaker Studies
Authors: CHANDIRAMANI SHANKER , COHORN LANDON C. , CHANDIRAMANI SARIKA
Published: July 2007

Background: Mental stress affects hemodynamic properties of the heart in patients indicated for a pacemaker, therefore highlighting the need for a rate‐adaptive sensor that responds to mental loads. One such sensor utilizes Closed Loop Stimulation (CLS), which translates right ventricular contractility into patient specific pacing rates. Clinical studies utilizing CLS [Emotional Response (ER) and Emotional Response 2 (ER2) studies] have been performed to confirm CLS provides appropriate heart rate response to acute mental stress. The objective of these studies was to compare heart rates during a mental stress test, with the patient's pacemaker programmed to a CLS pacing mode and an accelerometer pacing mode.

Methods: Patients were implanted with a BIOTRONIK Protos/CLS pacemaker (Berlin, Germany) and subjected to mental stress testing. The stress test consisted of a relaxation period followed by a color‐word test and an arithmetic challenge test. The ER2 study utilized a randomized study design, in which pacing mode testing order was randomized.

Results: Analysis included patients who exhibited at least 80% sensor‐driven heart rates during stress testing. Results for both studies demonstrated that CLS provided a statistically significant higher increase in heart rate during testing compared with an accelerometer pacing mode. The studies also showed that CLS provided a statistically significant higher peak heart rate during testing compared with an accelerometer pacing mode.

Conclusions: The ER and ER2 studies demonstrate that the CLS algorithm responds with an appropriate heart rate response to acute mental stress in patients exhibiting a high percentage of sensor‐driven pacing.
Testing the Implantable Cardioverter‐Defibrillator After Implantation—Is It Necessary?
Authors: SANDSTEDT BENGT , GOTTFRIDSSON CHRISTER , NYSTRÖM BRITTA , EDVARDSSON NILS
Published: July 2007

The results of intraoperative and postoperative predischarge implantable cardioverter‐defibrillator (ICD) testing of 211 consecutive patients, starting at 15 J and requiring two successful terminations of induced VT/VF with a relative defibrillation safety margin (DSM) of >10 J, were reviewed. The aim was to define the type of intraoperative response that would make postoperative predischarge testing unnecessary. The intraoperative responses were divided into three types: A, a DSM ≥10 J and an absolute energy level of ≤20 J; B, a DSM of ≥10 J and an absolute energy level of >20 J; and C, a DSM <10 J and an absolute energy level of >20 J. At operation, the responses to defibrillation were A, 88.6%; B, 7.1%; and C, 4.3%. Accepting an A response only would leave 11.4% of the patients for postoperative testing. The positive and negative predictive values for diagnosing a postoperative C response were 0.78 and 0.97, respectively. Similarly, the predictive values for diagnosing a postoperative B or C response were 0.71 and 0.97, respectively. The postoperative testing responses were A, 89.1%; B, 4.3%; and C, 6.6%. In summary, an intraoperative A response was sufficient to make a postoperative defibrillation testing unnecessary, while it was found that intraoperative B and C responders should undergo postoperative testing. Applying these criteria, approximately 90% of the patients could be discharged without any postoperative induction test.
Safety and Acceptability of Implantation of Internal Cardioverter‐Defibrillators Under Local Anesthetic and Conscious Sedation
Authors: FOX DAVID J. , DAVIDSON NEIL C. , BENNETT DAVID H. , CLARKE BERNARD , GARRATT CLIFFORD J. , HALL MARK C.S. , ZAIDI AMIR M. , PATTERSON KAY , FITZPATRICK ADAM P.
Published: July 2007

Background: Implantation and testing of implantable defibrillators (ICDs) using local anesthetic and conscious sedation is widely practiced; however, some centers still use general anesthesia. We assessed safety and patient acceptability for implantation of defibrillators using local anesthetic and conscious sedation.

Methods: The records of 500 consecutive device implants from two UK cardiac centers implanted under local anesthetic and conscious sedation from January 1996 to December 2004 were reviewed. Procedure time, left ventricular ejection fraction (LVEF) sedative dosage (midazolam), analgesic dosage (fentanyl or diamorphine), requirement for drug reversal, and respiratory support were recorded. Patient acceptability of the procedure was also assessed.

Results: Of 500 implants examined, 387 were ICDs, 88 were biventricular ICDs, and 25 were generator changes. Patients with biventricular‐ICDs had significantly longer (mean ± SD) procedure times 129.7 ± 7.6 minutes versus 63.3 ± 32.3 minutes; P < 0.0001 and lower LVEF 24.4 ± 8.4% versus 35.7 ± 15.4%; P < 0.0001. There were no differences in the doses (mean ± SD) of midazolam 8.9 ± 3.5 mg versus 8.0 ± 3.1 mg; P = NS, diamorphine 4.3 ± 2.0 mg versus 3.8 ± 1.7 mg; P = NS or fentanyl 94.4 ± 53.7 mcg versus 92.2 ± 48.6 mcg; P = NS, between the two groups. There were no deaths or tracheal intubations in either group. Acceptability was available for 373 of 500 (75%) patients, 41 of 373 (11%) described “discomfort,” but from these 41 patients only 14 of 373 (3.8%) declined a second procedure under the same conditions.

Conclusions: Implantation of defibrillators under local anesthetic and sedation is safe and acceptable to patients. General anesthesia is no longer routinely required for implantation of defibrillators.
Localization of Accessory Pathways in the Wolff‐Parkinson‐White Pattern—Physician Versus Computer Interpretation of the Same Algorithm
Authors: McGAVIGAN ANDREW D. , CLARK ELAINE , QUINN F. RUSSELL , RANKIN ANDREW C. , MACFARLANE PETER W.
Published: July 2007

Background: There are several published algorithms for the prediction of accessory pathway (AP) location in the Wolff‐Parkinson‐White syndrome from the 12‐lead electrocardiogram (ECG). Most depend on stepwise criteria, and minor disagreements between observers over QRS transition point or delta wave axis may lead to different classification of pathway location. We compared the utility of a computerized program in identifying pathway location from the ECG using the algorithm published by Fitzpatrick and coworkers3 against physician assessment with the same algorithm.

Methods: Thirty‐one 12‐lead ECGs with an overt preexcitation pattern were examined by three physicians and AP localized to one of eight anatomical sites using the Fitzpatrick algorithm, with disagreements resolved by consensus. Similarly, pathway location was determined by the Glasgow ECG program with the Fitzpatrick algorithm incorporated into its logic.

Results: The agreement between each physician and their consensus was 28/31, 29/31, and 29/31. Similarly, assessment by the Glasgow program produced agreement with the physician consensus in 29/31 cases. Of the 24 patients who underwent radiofrequency ablation, the program localized the pathway to the true or adjacent annular region in 20, compared to 20/24 by physician assessment of the algorithm, producing a similar predictive accuracy to published data.

Conclusion: This study has shown that incorporation of the Fitzpatrick algorithm for AP location into a widely used computer program results in the same level of performance as that of experienced physicians and may be useful in clinical practice as an aid to referral for electrophysiological study and ablation.
The Safety and Efficacy of Ibutilide in Children and in Patients with Congenital Heart Disease
Authors: HOYER ANDREW W. , BALAJI SESHADRI
Published: July 2007

Background: The safety and efficacy of ibutilide in the cardioversion of atrial flutter and atrial fibrillation in children and in patients with congenital heart disease (CHD) is unknown.

Methods: Data from 19 patients (age 6 months to 34 years, median 16 years) who received ibutilide for atrial flutter or atrial fibrillation between 1996 and 2005 was retrospectively reviewed. There were 15 patients with CHD (14 had prior heart surgery); four children had normal heart structure.

Results: There were 74 episodes of atrial flutter and four episodes of atrial fibrillation (median episodes per patient was one, range 1–31). Ibutilide converted 55 of all the episodes (71%). Ibutilide was successful during its first‐ever administration in 12 of 19 patients (63%). Fourteen episodes in six patients required electrical cardioversion after ibutilide failed. There were no episodes of symptomatic bradycardia. One patient went into torsade de pointes and one patient had nonsustained ventricular tachycardia.

Conclusion: With careful monitoring, ibutilide can be an effective tool in selected patients for cardioversion of atrial flutter.
Premature Ventricular Contractions with a Right Bundle Branch Block and Inferior QRS Axis Morphology: Where is the Site of the Origin?
Authors: YAMADA TAKUMI , HUIZAR JOSE F. , McELDERRY HUGH T. , KAY G. NEAL
Published: July 2007

A 63‐year‐old woman with symptomatic premature ventricular contractions (PVCs) underwent electrophysiologic testing. The PVCs were suggested to originate from the infra‐aortic valvular left ventricular outflow tract because the PVCs had S‐waves in leads I, V5, and V6, and an R/S ratio >1 in lead V1. However, during some PVCs without S‐waves, the ST segment had negative retrograde P‐waves with a longer ventricularatrial (VA) interval. A Radiofrequency (RF) application in the left coronary cusp completely eliminated the PVCs, suggesting that negative retrograde P‐waves might have been observed as pseudo S‐waves during the PVCs.
A Review of Spinal Injuries in the Invasive Cardiologist: Part 1. Biomechanics and Pain Generation
Authors: FADL YAZID Y. , ELLENBOGEN KENNETH A. , GRUBB ROBERT L. , KHOO‐SUMMERS LYNNETTE , LINDSAY BRUCE D.
Published: July 2007

This review provides a perspective of spinal injuries related to invasive cardiology, an understanding of the anatomy and physiology of the spine, the etiology and pathophysiology of spinal injuries, and options for prevention and treatment. Because of the breadth of this review, it has been divided into two parts with the first describing the biomechanics and generation of back pain and the second discussing treatment options and prevention of back injury. A comprehensive overview of the biomechanics of the spine from the individual vertebral unit to the complex motions involved in everyday life is reviewed. The significant intrinsic and extrinsic factors playing a role in the mechanism of disc damage, including occupational hazards encountered by the invasive cardiologist, are discussed. We also address the mechanisms of pain generation in the spine and the role that inflammation plays, which explains the presence of symptoms with little or no detectable pathology on imaging studies.
Change in Atrial Flutter Wave Morphology—Insight into the Sources of Electrocardiographic Variants in Common Atrial Flutter
Authors: ASHINO SONOKO , WATANABE ICHIRO , OKUMURA YASUO , OKUBO KIMIE , SAITO SATOSHI
Published: July 2007

Whether the activation sequence of the right or left atrium plays a role in the morphology of the flutter wave in common atrial flutter is not completely understood. We present two patients with common counterclockwise atrial flutter in whom changes in the left atrial activation sequence produced significant changes in flutter wave polarity (+ to − and − to −/+ biphasic) without a change in the activation sequence within the right atrium. These cases highlight the possible role of alterations of the interatrial connections in the genesis of atypical manifestations of common atrial flutter.
Radiofrequency Ablation of a “Concealed” Mahaim‐Type Accessory Pathway
Authors: BROADHURST PAUL , REDFERN CHRIS
Published: July 2007

We report a case of supraventricular tachycardia associated with left bundle branch block due to a slowly conducting right sided accessory pathway. Preexcitation of the ventricles could not be demonstrated during sinus rhythm or incremental atrial pacing but its presence was confirmed during antedromic tachycardia with critically timed atrial extrastimuli. The pathway was mapped during tachycardia and successfully ablated.
New Onset Postural Tachycardia Syndrome Following Lightning Injury
Authors: GRUBB BLAIR P. , KARABIN BEVERLY
Published: July 2007

Lightning injuries are one of the top three causes of death from environmental causes. Survivors of lightning injuries may be left with injuries, which may affect either the somatic or autonomic nervous systems. We report on two previously healthy patients who developed severe forms of postural tachycardia syndrome following a lightning injury, and review the literature on the subject.
Brugada Syndrome in the Presence of Coronary Artery Disease and Parasympathomimetic Drug Therapy
Authors: OTTEN RICHARD F. , DUSA ADRIAN C. , DAS MITHILESH K.
Published: July 2007

Brugada pattern ECG changes have been described in various disease states and drug therapies, including electrolyte abnormalities, myocardial pathology, medications, and mechanical abnormalities. Therefore, the diagnosis of Brugada syndrome cannot be made in the presence of confounding variables according to prevailing guidelines. We present a case report which illustrates two important principles regarding Brugada syndrome, the dynamic ECG manifestations and the elimination of confounding variables (in this case significant coronary artery disease and cholinergic pharmacotherapy) prior to definitive diagnosis.
QT Interval Prolongation and Torsades De Pointes Due to a Coadministration of Ciprofloxacin and Azimilide in a Patient with Implantable Cardioverter–Defibrillator
Authors: KAŹMIERCZAK JAROSAW , PEREGUD‐POGORZELSKA MAGORZATA , RZEUSKI RYSZARD
Published: July 2007

The presented case report describes a male patient with an implanted cardioverter–defibrillator (ICD) in whom a coadministration of ciprofloxacin and azimilide caused QT interval prolongation and multiple episodes of torsades de pointes (TdP) followed by ICD shocks (arrhythmic storm). The case highlights a not described drug interaction between azimilide and ciprofloxacin, which is believed to be the safest member of fluoroquinolones class.
Concordance Between Mechanical and Electrical Dyssynchrony in Heart Failure Patients: A Function of the Underlying Cardiomyopathy?
Authors: TOURNOUX FRANÇOIS , DONAL ERWAN , LECLERCQ CHRISTOPHE , DE PLACE CHRISTIAN , CROCQ CHRISTOPHE , SOLNON AUDE , COHEN‐SOLAL ALAIN , MABO PHILIPPE , DAUBERT JEAN‐CLAUDE
Published: July 2007

Background: Cardiac resynchronization therapy (CRT) improves heart failure (HF) symptoms through a reduction of cardiac mechanical dyssynchrony. Mechanical dyssynchrony is currently estimated by electrical dyssynchrony (QRS duration). It is known that electrical and mechanical dyssynchrony are not well correlated in HF patients. However, there is limited information about whether this relationship might be influenced by the underlying cardiomyopathy.

Methods: Doppler echocardiography was performed in 88 patients presenting with heart failure due to ischemic (n = 42) or nonischemic (n = 46) heart disease, left ventricular ejection fraction <40%, New York Heart Association class II–IV, regardless of their QRS duration. Interventricular dyssynchrony was assessed by the time interval between preaortic and prepulmonary ejection times. Intraventricular dyssynchrony was ascertained by (1) the delay between the earliest and the latest peak negative longitudinal strain recorded in the basal and mid‐segments of the lateral and septal walls (TMinMax) and (2) the standard deviation of time‐to‐peak in the same segments (SDdys).

Results: The correlation coefficient between QRS duration and mechanical interventricular dyssynchrony was r = 0.47 (P < 0.001) in patients with nonischemic disease and nonsignificant in patients with ischemic disease. Similarly, the correlation coefficient between QRS duration and mechanical intraventricular dyssynchrony was significant in patients with nonischemic disease (r = 0.37, P = 0.01 for TMinMax; r = 0.42, P = 0.003 for SDdys) and nonsignificant in patients with ischemic disease.

Conclusion: The concordance between electrical dyssynchrony assessed by QRS duration and mechanical dyssynchrony assessed by myocardial strain is dependent upon the underlying cardiomyopathy. This observation may improve our understanding of the various responses observed in CRT patients.
Autonomic Tone Attenuates Drug‐Induced QT Prolongation
Authors: SMITH ANDREW H. , NORRIS KRIS J. , RODEN DAN M. , KANNANKERIL PRINCE J.
Published: July 2007

Introduction: The QT interval is a predictor of sudden death. Many drugs prolong the QT, primarily through IKr block. Autonomic tone directly affects heart rate and ventricular repolarization, but its effects in the setting of IKr block are unknown.

Objective: Determine the effects of autonomic tone on heart rate and QT interval after IKr block.

Methods and Results: Healthy adults (n = 9) were administered ibutilide with ECGs obtained at regular intervals. On a separate day, subjects were administered intravenous propranolol and atropine to induce autonomic block, resulting in intrinsic heart rate and QT interval; ibutilide was administered again, with serial ECGs obtained at regular intervals. No differences in baseline RR, QT, or QTc intervals were seen between the two study days. Ibutilide in the setting of intact autonomic tone prolonged QTc by 43 ± 8 msec (P = 0.001) and prolonged RR interval by 93 ± 39 msec (P = 0.04). Autonomic block alone on the second day prolonged QTc by 16.7 ± 9.4 msec (P = 0.02). An additional 68 ± 5 msec prolongation of QTc was seen with ibutilide in the setting of double autonomic block (P = 0.036). There was no effect of ibutilide on intrinsic heart rate (P = 0.125).

Conclusion: Autonomic block results in an exaggeration of drug‐induced QT prolongation by ibutilide. IKr block has no effect on intrinsic heart rate. QT‐prolonging drugs may have more deleterious effects in those with underlying autonomic dysfunction, thus increasing the risk for sudden death.
Cost Comparison of Catheter Ablation and Medical Therapy in Atrial Fibrillation
Authors: KHAYKIN YAARIV , MORILLO CARLOS A. , SKANES ALLAN C. , MCCRACKEN AARON , HUMPHRIES KARIN , KERR CHARLES R.
Published: July 2007

Introduction: There is emerging evidence for clinical superiority of catheter ablation over rate and rhythm control strategies in paroxysmal atrial fibrillation (PAF). The objective of this study was to compare costs related to medical therapy versus catheter ablation for PAF in Ontario (Canada).

Methods: Costs related to medical therapy in the analysis included the cost of anticoagulation, rate and rhythm control medications, noninvasive testing, physician follow‐up visits, and hospital admissions, as well as the cost of complications related to this management strategy. Costs related to catheter ablation were assumed to include the cost of the ablation tools (electroanatomic mapping or intracardiac echocardiography‐guided pulmonary vein ablation), hospital and physician billings, and costs related to periprocedural medical care and complications. Costs related to these various elements were obtained from the Canadian Registry of Atrial Fibrillation (CARAF), government fee schedules, and published data. Sensitivity analyses looking at a range of initial success rates (50–75%) and late attrition rates (1–5%), prevalence of congestive heart failure (CHF) (20–60%), as well as discounting varying from 3% to 5% per year were performed.

Results: The cost of catheter ablation ranged from $16,278 to $21,294, with an annual cost of $1,597 to $2,132. The annual cost of medical therapy ranged from $4,176 to $5,060. Costs of ongoing medical therapy and catheter ablation for PAF equalized at 3.2–8.4 years of follow‐up.

Conclusion: Catheter ablation is a fiscally sensible alternative to medical therapy in PAF with cost equivalence after 4 years.
Slow Atrioventricular Nodal Reentrant Arrhythmias: Clinical Recognition, Electrophysiological Characteristics, and Response to Radiofrequency Ablation
Authors: VIJAYARAMAN PUGAZHENDHI , ALAEDDINI JAMSHID , STORM RANDLE , OREN JESSE , WOOD MARK A , ELLENBOGEN KENNETH A.
Published: July 2007

Background: Atrioventricular nodal reentrant tachycardia (AVNRT) is a common form of supraventricular tachycardia (SVT). Rarely, patients may present with an unusual form of atrioventricular nodal reentrant arrhythmia (AVNRA) with a cycle length greater than 600 ms. We describe the clinical presentation, electrophysiology characteristics, and response to radiofrequency ablation in a group of patients with AVNRA.

Methods and Results: Six patients with slow documented sustained supraventricular arrhythmias at rates <100 bpm underwent electrophysiology study. Baseline clinical and electrophysiologic characteristics were: mean age 77 ± 5 years; left ventricular ejection fraction 51 ± 10%; hypertension 66%; diabetes mellitus 33%; coronary artery disease 33%; sinus cycle length 874 ± 110 ms; PR 261 ± 54 ms; atrial to His (AH) 181 ± 49 ms. AVNRA was diagnosed based on previously described criteria for AVNRT. Mean tachycardia cycle length (TCL) during AVNRA was 668 ± 74 ms. The AH and His to atrial (HA) intervals during the AVNRA was 434 ± 50 and 234 ± 81 ms, respectively. Two patients had slow–fast AVNRA while the others had slow–slow AVNRA. Most common symptoms reported during AVNRA were shortness of breath, fullness in the throat, chest tightness, dizziness, near‐syncope, and syncope. Radiofrequency catheter ablation (RFCA) of the slow pathway was performed successfully in five of six patients. Post‐ablation AV nodal Wenckebach occurred at 666 ± 49 ms compared with 521 ± 91 ms at baseline.

Conclusion: AVNRA may occur at rates less than 100 bpm in the elderly and may be misdiagnosed as junctional rhythm. Slow AVNRA can cause significant symptoms. Slow pathway ablation can be successfully performed in AVNRA.
A Novel Early Onset Lethal Form of Catecholaminergic Polymorphic Ventricular Tachycardia Maps to Chromosome 7p14‐p22
Authors: BHUIYAN ZAHURUL A. , HAMDAN MOHAMED A. , SHAMSI EMAN T.A. , POSTMA ALEX V. , MANNENS MARCEL M.A.M. , WILDE ARTHUR A. M. , AL‐GAZALI LIHADH
Published: July 2007

Introduction: Previously, autosomal dominant catecholaminergic polymorphic ventricular tachycardia (CPVT [1]) was mapped to chromosome 1q42–43 with identification of pathogenic mutations in RYR2. Autosomal recessive CPVT (2) was mapped to chromosome 1p13–21, leading to the identification of mutations in CASQ2. In this study, we aimed to elucidate clinical phenotypes of a new variant of CPVT (3) in an inbred Arab family and also delineate the chromosomal location of the gene causing CPVT (3).

Methods and Results: In a highly inbred family, clinical symptoms of CPVT appeared early in childhood (7–12 years) and in three of the four cases, the first appearance of symptoms turned into a fatal outcome. Parents of the affected children were first‐degree cousins and without any symptoms. Segregation analysis suggested an autosomal recessive inheritance. A genome‐wide search using polymorphic DNA markers mapped the disease locus to a 25‐Mb interval on chromosome 7p14‐p22. A maximal multipoint LOD score of 3.17 was obtained at marker D7S493. Sequencing of putative candidate genes, SP4, NPY, FKBP9, FKBP14, PDE1C, and TBX20, in and around this locus, did not reveal any mutation.

Conclusions: We have identified a novel highly malignant autosomal recessive form of CPVT and mapped this disorder to a 25‐Mb interval on chromosome 7p14‐p22.
Effect of Pacing the Right Ventricular Mid‐Septum Tract in Patients with Permanent Atrial Fibrillation and Low Ejection Fraction
Authors: MUTO CARMINE , OTTAVIANO LUCA , CANCIELLO MICHELANGELO , CARRERAS GIOVANNI , CALVANESE RAIMONDO , ASCIONE LUIGI , IENGO RAFFAELE , ACCADIA MARIA , CELENTANO EDUARDO , TUCCILLO BERNARDINO
Published: July 2007

Introduction: Permanent right ventricular (RV) pacing leads have been traditionally implanted in the right ventricular apex (RVA). Nowadays, some deleterious effects of RVA pacing have been recognized. The aim of this study was to evaluate the effect of different sites of RV pacing in patients with permanent atrial fibrillation (AF) and low ejection fraction (LEF) needing a pacemaker (PM) implantation.

Methods: Two hundred seventy‐three patients with permanent AF and EF <30% underwent a one‐chamber rate responsive (VVIR) PM implant procedure. Patients were divided into two groups: Group A, including 113 patients with the pacing lead tip placed in the RV mid‐septum, and Group B of 120 patients with the pacing lead tip placed at the apex of RV. All patients had clinical and Echo control after 1, 3, 6, 12, and 18 months after PM implantation to assess New York Heart Association (NYHA) class and EF.

Results: After 18 months, NYHA class changed in Group A from 2.9 ± 0.4 at implant to 1.7 ± 0.3 at 18 months (P = 0.01), and in Group B from 3.0 ± 0.5 at implant to 3.3 ± 0.6 at 18 months (P = n.s.). EF increased in Group A: 28 ± 2% at implant, 33 ± 1% at 18 months (P = 0.0125), while no significant changes were observed in Group B: at implant 27 ± 2%, 26 ± 2% at 18 months (P = n.s.).

Conclusion: The present study suggests that more physiological pacing from the RV sept can improve EF and quality of life (QoL) in patients with permanent AF and low EF needing a PM.
Entrainment Mapping of a Concealed Nodoventricular Accessory Pathway in a Man with Complete Heart Block and Tachycardia‐Induced Cardiomyopathy
Authors: QUINN F. RUSSELL , MITCHELL L. BRENT , MARDELL ANDREW P. , DAL DISLER R.N. , VEENHUYZEN GEORGE D.
Published: July 2007

True nodoventricular (NV) accessory connections, as originally described by Mahaim, are rare entities, with the majority of previously reported cases now recognized as being due to decremental atriofascicular pathways. Here, we present a patient with incessant narrow and wide QRS complex tachycardia occurring in the setting of prior complete heart block. Entrainment mapping proved useful in diagnosing orthodromic reentry utilizing a concealed right septal NV pathway. The patient was successfully treated with radiofrequency ablation, resulting in a marked improvement in left ventricular function.
Thermodynamic Characterization of the Eutectic Phase Mixture NaNbO3/Na3NbO4. I: Literature Survey
Authors: Näfe Helfried , Amin Ruhul , Aldinger Fritz
Published: July 2007

The literature about the thermodynamic properties of NaNbO3 and Na3NbO4 has mainly been governed by estimations. The only exceptions are two current calorimetric investigations on the standard enthalpy of formation of NaNbO3 and, in addition, an old and inappropriately evaluated study on the carbon dioxide equilibrium gas pressure over the phase mixture NaNbO3/Na3NbO4/Na2CO3. Upon reevaluating the latter results, first experimentally proven data on the difference of the Gibbs‐free energies have been obtained (715°–822°C):

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Magneto‐Dielectric Properties of Mg–Cu–Co Ferrite Ceramics: I. Densification Behavior and Microstructure Development
Authors: Kong L. B. , Li Z. W. , Lin G. Q. , Gan Y. B.
Published: July 2007

The densification, grain growth, and microstructure development of Mg–Cu–Co ferrite ceramics (MgFe1.98O4, Mg1−xCuxFe1.98O4, with x=0.10–0.30 and Mg0.90−xCoxCu0.10Fe1.98O4, with x=0.05–0.20) were studied. The primary objective was to develop magneto‐dielectric materials for miniaturization of high frequency and very‐high frequency antennas. It was found that magnesium ferrite (MgFe1.98O4) is a promising magneto‐dielectric material. However, due to its poor densification, it could not be fully sintered at a temperature below 1200°C. High‐temperature sintering resulted in undesirable electrical and dielectric properties, due to the formation of Fe2+ ions. The poor densification and slow grain growth rate of MgFe1.98O4 can be considerably improved by incorporating Cu, due to the occurrence of liquid‐phase sintering at a high temperature. A critical concentration of Cu was observed for Mg1−xCuxFe1.98O4, above which both densification and grain growth were maximized or saturated. The presence of Co did not have a significant influence on the densification and grain growth of the Mg‐based ferrite ceramics.
Quantitative Phase Analysis of Laboratory‐Active Belite Clinkers by Synchrotron Powder Diffraction
Authors: Morsli Khadija , De La Torre Ángeles G. , Stöber Stephan , Cuberos Antonio J. M. , Zahir Mohammed , Aranda Miguel A. G.
Published: July 2007

Several active belite laboratory clinkers with a theoretical composition of 60 wt% of C2S have been synthesized. The activation process has been carried out by adding variable amounts of alkaline salts, K2CO3, or Na2CO3to the raw materials. In addition to an ordinary Portland clinker and a nonactive belite clinker, four active belite clinkers have been prepared with 1.0 and 2.0 wt% of K2O or 0.5 and 1.5 wt% of Na2O. Phase‐enriched residues, silicate, and aluminate fractions have also been prepared in order to identify the most suitable structural description for each phase. High‐resolution synchrotron X‐ray powder diffraction patterns have been collected for the residues and for the laboratory clinkers. Quantitative phase analyses were performed by the Rietveld method using the synchrotron patterns. The reference belite laboratory clinker has a large amount of β‐C2S but the addition of alkaline salts to raw mixtures promotes the stabilization at room temperature of the highest temperature polymorphs: α′H‐C2S and α‐C2S. As an example, the active belite clinker with 2.0 wt% nominal content of K2O contains 4.5(2) wt% of β‐C2S, 19.2(1) wt% of α′H‐C2S, 35.9(2) wt% of α‐C2S, 17.6(1) wt% of C3S, 13.2(1) wt% of total C3A, and 9.6(1) wt% of C4AF. The role of K2O and Na2O, which stabilize different polymorphs, will be discussed. The partial volatilization of the alkaline metals will also be addressed. Finally, a calorimetric study has been undertaken in order to correlate the phase assemblage determined in the powder diffraction study with the hydration behavior.
A Limited Review of Water Diffusivity and Solubility in Glasses and Melts
Authors: Shelby James E.
Published: July 2007

A limited review of the literature dealing with water solubility and diffusion in oxide glasses and melts is presented, with an emphasis on simple and commercial compositions and on work during the past decade. Several methods for determination of water solubilities and diffusivities are discussed. Experimental results are presented for silicate, borate, and germanate glasses and melts. Water diffusivities always increase with increasing temperature and modifier oxide content in these melts. Variations in water solubility and diffusivity with alkali and alkaline earth identity for otherwise identical compositions are small, while variations with the identity of the glass‐forming oxide are large. Water solubility increases with increasing modifier oxide content in alkali silicate melts, but decreases with increasing modifier oxide content in alkali borate and germanate melts.
Visual response of the tomato fruit fly, Neoceratitis cyanescens, to colored fruit models
Authors: Brévault T. , Quilici S.
Published: July 2007

To determine how mature females of the tomato fruit fly, Neoceratitis cyanescens (Bezzi) (Diptera: Tephritidae), detect host fruit after arriving in their host plant habitat, behavioral responses to colored models were observed in a laboratory flight chamber. Host‐seeking females oriented themselves preferentially towards bright orange spheres (3.7 cm in diameter), irrespective of their natal host fruit: tomato, bug weed, or black nightshade. Females oriented themselves preferentially towards the orange sphere when placed against a fluorescent yellow background as opposed to a black background, but the distribution of responses to the set of colored spheres did not vary significantly with background color. In a choice situation between bright orange spheres of various sizes (1.9, 3.7, and 7.5 cm in diameter), females landed preferentially on the bigger sphere. However, they preferred a yellow color when the latter was associated with two‐dimensional models, probably mimicking leaves. The attractiveness of orange spheres depended more on the proportion of reflected light in the spectral region around 610 nm than brightness of color in itself. Low light intensity significantly influenced the activity of the flies but not their visual preference. The strong response of females to bright orange spheres confirmed the importance of visual characteristics in short‐range mechanisms of host‐plant location in specialist insects. Responses to fruit visual stimuli are discussed relative to other Tephritidae, host‐finding strategy, and pest management.
Modeled global invasive potential of Asian gypsy moths, Lymantria dispar
Authors: Peterson A. Townsend , Williams Richard , Chen Guojun
Published: July 2007

Asian populations of gypsy moths, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), remain poorly characterized – indeed, they are not presently accorded any formal taxonomic status within the broader species. Their ecology is similarly largely uncharacterized in the literature, except by assumption that it will resemble that of European populations. We developed ecological niche models specific to Asian populations of the species, which can in turn be used to identify a potential geographic distributional area for the species. We demonstrated statistically significant predictivity of distributional patterns within the East Asian range of these populations; projecting the Asian ecological niche model to Europe, correspondence with European distributions was generally good, although some differences may exist; projecting the ecological niche model globally, we characterized a likely potential invasive distribution of this set of populations across the temperate zone of both Northern and Southern Hemisphere.
Incontinence in the aged: contact dermatitis and other cutaneous consequences
Authors: Farage Miranda A. , Miller Kenneth W. , Berardesca Enzo , Maibach Howard I.
Published: July 2007

Urinary and faecal incontinence affects a significant portion of the elderly population. The increase in the incidence of incontinence is not only dependent on age but also on the onset of concomitant ageing issues such as infection, polypharmacy, and decreased cognitive function. If incontinence is left untreated, a host of dermatological complications can occur, including incontinence dermatitis, dermatological infections, intertrigo, vulvar folliculitis, and pruritus ani. The presence of chronic incontinence can produce a vicious cycle of skin damage and inflammation because of the loss of cutaneous integrity. Minimizing skin damage caused by incontinence is dependent on successful control of excess hydration, maintenance of proper pH, minimization of interaction between urine and faeces, and prevention of secondary infection. Even though incontinence is common in the aged, it is not an inevitable consequence of ageing but a disorder that can and should be treated. Appropriate clinical management of incontinence can help seniors continue to lead vital active lives as well as avoid the cutaneous sequelae of incontinence.