bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preserved Left Ventricular Ejection Fraction Following Atrioventricular Junction Ablation and Pacing for Atrial Fibrillation
Authors: CHEN LIN , HODGE DAVID , JAHANGIR ARSHAD , OZCAN CEVHER , TRUSTY JANE , FRIEDMAN PAUL , REA ROBERT , BRADLEY DAVID , BRADY PETER , HAMMILL STEPHEN , HAYES DAVID , SHEN WIN‐KUANG 
Published: October 2007

Introduction: Right ventricular apical (RVA) pacing creates ventricular dyssynchrony and may compromise left ventricular ejection fraction (LVEF). The impact of RVA pacing in patients who have undergone atrioventricular junction (AVJ) ablation for atrial fibrillation (AF) is unclear. We sought to determine whether RVA pacing after AVJ ablation for patients with AF compromises LVEF in the short‐ or long‐term. Methods/Results: We studied 286 patients with AF who underwent AVJ ablation and RVA pacing at our institution between 1990 and 2002. Patients were stratified into a short‐term follow‐up group (LVEF reassessed by echocardiography within a year after AVJ ablation, n = 134) and a long‐term group (LVEF reassessed after a year, n = 152). Among all 286 patients (mean follow‐up 20 months), we observed no change in mean LVEF after AVJ ablation and RVA pacing (48% before vs. 48% after, P = 0.42). Short‐term follow‐up patients had a statistically significant improvement in mean LVEF (46% before vs. 49% after, P = 0.03), whereas there was no statistically significant change in mean LVEF in long‐term follow‐up patients (49% before vs. 48% after, P = 0.37). Only 9% of short‐term patients, 15% of long‐term patients, and 1% of patients with baseline LVEF ≤ 40% experienced ≥10% absolute decrease in LVEF. Baseline LVEF > 40% was a multivariate predictor of LVEF decline. Conclusions: RVA pacing after AVJ ablation does not compromise LVEF in the short‐ or long‐term for the vast majority of patients. Better predictors are needed to help us select patients for biventricular pacing after AVJ ablation.
Left Ventricular Conduction Delays Induced by Right Ventricular Apical Pacing: Effect of Left Ventricular Dysfunction and Bundle Branch Block
Authors: VARMA NIRAJ 
Published: October 2007

Background: RV apical pacing (RVP) may be deleterious, possibly by simulating LBBB, i.e., prolonging QRS duration (QRSd) and LV activation (LVAT). However, determinants of electrical delays are unknown. Hypothesis: LV dysfunction (LVEF ≤ 40%, HF) and pre‐existing conduction system abnormalities may modulate RVP's effects, compared to LBBB. Methods: RVP‐induced QRSd and LVAT were compared in normal LV to HF, with normal QRS (<120 ms), RBBB, or LBBB. LVAT was estimated by interval from QRS onset to basal inferolateral LV depolarization. Results: During LBBB and RVP, LVAT/QRSd was ≥85%, i.e., LVAT indicated terminal LV depolarization. In normal LV, LVAT during intrinsic conduction (55 ± 18 ms) was delayed by RVP (129 ± 20 ms, n = 58, P < 0.001). RVP's effects were similar to LBBB (P = NS) and unaffected by baseline conduction disease. In HF overall, RVP‐induced delays (QRSd 209 ± 27, LVAT 186 ± 26 ms, n = 102) were greater than RVP in normal LV (P < 0.001). When baseline conduction system disease was present, RVP's effects were exaggerated (RVP wide QRS [>120 ms]: QRSd 216 ± 27, LVAT 191 ± 20 ms, [n = 72] vs RVP normal QRS: QRSd 193 ± 24, LVAT 169 ± 24 ms, n = 31, P < 0.001). In patients with LBBB (n = 41), delays during intrinsic conduction (QRSd 163 ± 29, LVAT 137 ± 33 ms, n = 41) were enhanced by RVP (QRSd 218 ± 28, LVAT 191 ± 22 ms, P < 0.001). RVP's effects were similar in patients with LBBB and RBBB (P = NS). Conclusion: RVP simulated LBBB in normal LV. In HF, RVP induced greater conduction delays than LBBB, enhanced by accompanying conduction disease. These variations may contribute to RVP's mixed clinical effects.
A Novel Hybrid Transcatheter Ablation System That Combines Radiofrequency and Cryoenergy
Authors: KHAIRY PAUL , CARTIER CATHERINE , CHAUVET PATRICK , TANGUAY JEAN‐FRANÇOIS , SIMÉON BERTIN , LALONDE JEAN‐PIERRE , DUBUC MARC 
Published: October 2007

Introduction: Radiofrequency (RF) and cryoenergy are largely considered independent modalities for the transcatheter ablation of cardiac arrhythmias. There are numerous theoretical advantages to engineering a system capable of delivering both energy forms. Methods and Results: We designed a hybrid steerable catheter capable of delivering RF and cryoenergy independently, sequentially, and simultaneously. The novel catheter system was tested pre‐clinically by creating a total of 180 ablation lesions in 20 mongrel dogs. Right atrial and right and left ventricular sites were preselected by a randomized factorial design devised to compare sequential and simultaneous RF and cryoenergy applications to standard RF, irrigated RF, and standard cryoablation. A steerable 4‐mm electrode‐tip hybrid catheter (“Fire and Ice”) was created by modifying a 7 F cryocatheter (Freezor™, CryoCath Technologies, Montreal, Canada). RF energy was injected via a copper wire, thermocouples were isolated to reduce RF interference, and 100 KHz band pass filters and RF chokes were added. Sequential low‐dose RF (20 W, 60 seconds) preceding or following cryoablation resulted in larger lesions (P = 0.0010). The addition of RF energy did, however, produce more thrombus than cryoenergy alone, with clot detected on 82.4% versus 12.1% of ablation lesions, P < 0.0001. Simultaneously applying the two energy modalities (45 W, 10 or 30°C, 60 seconds) created more voluminous lesions than standard RF ablation (median 288.1 vs 126.1 mm3, P = 0.0333) of similar dimension to irrigated RF ablation. Conclusion: A versatile catheter system was fashioned capable of creating standard cryoablation lesions, standard RF lesions, and simultaneous lesions of similar dimension to irrigated RF.
Association of Congenital, Diffuse Electrical Disease in Children with Normal Heart: Sick Sinus Syndrome, Intraventricular Conduction Block, and Monomorphic Ventricular Tachycardia
Authors: ITURRALDE‐TORRES PEDRO , NAVA‐TOWNSEND SANTIAGO , GÓMEZ‐FLORES JORGE , MEDEIROS‐DOMINGO ARGELIA , COLÍN‐LIZALDE LUIS , HERMOSILLO ANTONIO G. , VICTORIA DIANA , MÁRQUEZ MANLIO F. 
Published: October 2007

Introduction: Rhythm disturbances in children with structurally normal hearts are usually associated with abnormalities in cardiac ion channels. The phenotypic expression of these abnormalities (“channelopathies”) includes: long and short QT syndromes, Brugada syndrome, congenital sick sinus syndrome, catecholaminergic polymorphic ventricular tachycardia, Lènegre‐Lev disease, and/or different degrees of cardiac conduction disease. Methods: The study group consisted of three male patients with sick sinus syndrome, intraventricular conduction disease, and monomorphic sustained ventricular tachycardia. Clinical data and results of electrocardiography, Holter monitoring, electrophysiology, and echocardiography are described. Results: In all patients, the ECG during sinus rhythm showed right bundle branch block and long QT intervals. First‐degree AV block was documented in two subjects, and J point elevation in one. A pacemaker was implanted in all cases due to symptomatic bradycardia (sick sinus syndrome). Atrial tachyarryhthmias were observed in two patients. The common characteristic ventricular arrhythmia was a monomorphic sustained ventricular tachycardia, inducible with ventricular stimulation and sensitive to lidocaine. In one patient, radiofrequency catheter ablation was successfully performed. No structural abnormalities were found in echocardiography in the study group. Conclusion: Common clinical and ECG features suggest a common pathophysiology in this group of patients with congenital severe electrical disease.
Finite Element Analysis of Stent Deployment: Understanding Stent Fracture in Percutaneous Pulmonary Valve Implantation
Authors: SCHIEVANO SILVIA , PETRINI LORENZA , MIGLIAVACCA FRANCESCO , COATS LOUISE , NORDMEYER JOHANNES , LURZ PHILIPP , KHAMBADKONE SACHIN , TAYLOR ANDREW M. , DUBINI GABRIELE , BONHOEFFER PHILIPP 
Published: October 2007

Objectives: To analyze factors responsible for stent fracture in percutaneous pulmonary valve implantation (PPVI) by finite element method.
Background: PPVI is an interventional catheter‐based technique for treating significant pulmonary valve disease. Stent fracture is a recognized complication.
Methods: Three different stent models were created: (1) platinum–10% iridium alloy stent – resembles the first‐generation PPVI device; (2) same geometry, but with the addition of gold over the strut intersections – models the current stent; (3) same design as 1, but made of thinner wire. For Model 3, a stent‐in‐stent solution was applied. Numerical analyses of the deployment of these devices were performed to understand the stress distribution and hence stent fracture potential.
Results: Model 1: Highest stresses occurred at the strut intersections, suggesting that this location may be at highest risk of fracture. This concurs with the in vivo stent fracture data. Model 2: Numerical analyses indicate that the stresses are lower at the strut intersections, but redistributed to the end of the gold reinforcements. This suggests that fractures in this device may occur just distal to the gold. This is indeed the clinical experience. Model 3 was weakest at bolstering the implantation site; however, when two stents were coupled (stent‐in‐stent technique), better strength and lower stresses were seen compared with Model 1 alone.
Conclusions: Using finite element analysis of known stents, we were able to accurately predict stent fractures in the clinical situation. Furthermore, we have demonstrated that a stent‐in‐stent technique results in better device performance, which suggests a novel clinical strategy.
Influence of Paper Electrocardiogram Digitizing on T Wave and QRS Complex Morphology Parameters
Authors: Karsikas Mari , Huikuri Heikki , Perkiömäki Juha S. , Lehtola Lea , Seppänen Tapio 
Published: October 2007

Backround:Many morphological parameters of the electrocardiogram (ECG) can be calculated from a digital ECG and paper prints of ECG after digitizing. However, the digitizing process, including printing, scanning, ECG contour extraction, and alignment, can produce changes to the signals, reducing the reliability of some sensitive parameters of QRS complex and T wave.Methods:The influence of the digitizing process on the parameters of T wave and QRS complex morphology was studied by comparing systematically the values of the nine ECG morphology parameters, computed from the digital ECG and the corresponding paper ECG. The robustness of the parameters to the digitizing process and their discrimination ability between healthy subjects and postinfarction patients were investigated.Results:The standard T wave parameters and all selected dipolar loop‐parameters retained their robustness and discrimination ability during the digitizing process of the paper ECGs. The non‐dipolar parameters distorted strongly, especially those of the QRS complex. The T wave‐based non‐dipolar parameters retained their discrimination ability during the digitizing process.Conclusions:The selected standard T wave parameters and the dipolar loop‐parameters calculated from properly digitized ECG paper prints can be utilized in patient studies. Non‐dipolar parameters distort strongly but T wave‐based parameters retain discriminatory information.
Prevalence of Interatrial Block in a General Population of Elderly People
Authors: Ninios Ilias , Pliakos Christodoulos , Ninios Vlasios , Karvounis Haralampos , Louridas George 
Published: October 2007

Background: Interatrial block (IAB: P wave ≥ 110 ms) is highly prevalent in people ≥65 years old living in a community. Methods: We investigated 720 consecutive people age ≥65 years old, from the general population, with the intention of evaluating the prevalence of IAB in their electrocardiogram. After excluding 42 people with atrial fibrillation and atrial flutter (5%) or having a permanent pacemaker (0,83%), we evaluated the electrocardiograms of the remaining 678 people with sinus rhythm. Results: We identified 400 (59%) persons with IAB with a similar distribution between men (58.5%) and women (59.4%). IAB was also identified in 347 from a total of 570 hypertensive people (60,9%) and only in 53 out of 108 (49.1%) nonhypertensive people (P = 0.015). Conclusions: The surprisingly large prevalence of the IAB in the general older population emphasizes the importance of the early recognition of this abnormality from the surface 12‐lead electrocardiogram.
Detection of Proximal Coronary Occlusion in Acute Coronary Syndrome: A Feasibility Study Using Computerized Electrocardiographic Analysis
Authors: Eskola Markku J. , Nikus Kjell C. , Voipio‐Pulkki Liisa‐Maria , Huhtala Heini , Lund Juha , Ilva Tuomo , Niemelä Kari O. , Porela Pekka 
Published: October 2007

Background: Rapid identification of a proximal occlusion site of a major coronary artery is of paramount importance in the care of myocardial infarction (MI). It is increasingly recognized that routine electrocardiogram (ECG) can be used for that purpose, provided that expert interpretation is available. Computer‐based signal analysis has potential to enhance early ECG interpretation but its performance must be validated against manual algorithms. We therefore set out to develop a computer‐assisted model to detect proximal occlusion of the left anterior descending coronary artery (LAD) in patients with suspected acute coronary syndrome (ACS). Methods: Based on manual anatomical interpretation of the ECG, obtained from 216 consecutive patients who were admitted due to suspected ACS, an automatic computerized ECG model to detect LAD occlusion was constructed. Agreement between manual evaluation of the ECG by two cardiologists and a computerized ECG algorithm to detect occlusion of the LAD and the site of occlusion was determined. Results: Using an expert electrocardiographer's anatomical interpretation as the gold standard, the computer model recognized patients fulfilling ECG criteria for any occlusion of the LAD with a specificity of 99% and a sensitivity of 67% (κ= 0.71). However, proximal LAD occlusion was detected with 100% specificity and 86% sensitivity (κ= 0.72). The computer program detected a distal occlusion in the LAD with a specificity of 99% and a sensitivity of 40% (κ= 0.72). Conclusions: Computerized anatomical interpretation of the ECG is feasible and allows detection of a proximal LAD occlusion with excellent accuracy.
Analyses of Dynamic Beat‐to‐Beat QT–TQ Interval (ECG Restitution) Changes in Humans under Normal Sinus Rhythm and Prior to an Event of Torsades de Pointes during QT Prolongation Caused by Sotalol
Authors: Fossa Anthony A. , Wisialowski Todd , Crimin Kimberly , Wolfgang Eric , Couderc Jean‐Philippe , Hinterseer Martin , Kaab Stefan , Zareba Wojciech , Badilini Fabio , Sarapa Nenad 
Published: October 2007

Background: Restitution through intracardiac pacing has been used to assess arrhythmia vulnerability. We examined whether analyses of sequential beat‐to‐beat QT and TQ interval measures can be used to quantify ECG restitution changes under normal sinus rhythm. Methods: The QT, R‐R and TQ intervals were examined 22.5 hour Holter monitoring before and after oral sotalol in normal male and female volunteers. Additionally, comparisons were made to those observed in the time‐matched dataset prior to torsades de pointes in a heart diseased patient that received a single dose of sotalol. Results: Sotalol increased QT, R‐R and TQ intervals 71, 101, and 125 ms after 160 mg (n = 38) and 194, 235, and 135 ms after 320 mg (n = 19) during maximum plasma concentrations, respectively. The percentage of beats with a QT/TQ ratio >1 was reduced 25% over the entire 22.5 hours after sotalol and the lower TQ interval boundary (5th quantile) was increased 22–30%. In contrast, 99% of the beats prior to torsades de pointes had a QT/TQ ratio > 1 and the median TQ interval was below the lower 98% confidence bounds of normals before and after sotalol. Conclusions: ECG restitution changes are quantifiable under varying states (nocturnally, beta‐adrenergic blockade, QT prolongation) in healthy subjects.
Exercise‐Induced ST‐Segment Elevation in Patients with a Recent Acute Myocardial Infarction Treated by Primary Percutaneous Coronary Intervention
Authors: Infusino Fabio , Lanza Gaetano A. , Larosa Claudio , Sgueglia Gregory A. , Marinaccio Leonardo , Lamendola Priscilla , Mariani Luca , Santangeli Pasquale , Sestito Alfonso , Crea Filippo 
Published: October 2007

Objectives: To get insight in the mechanism of exercise‐induced ST‐segment elevation (STE) in patients with Q/QS waves at the electrocardiogram (ECG). Methods: We performed exercise stress test in 13 patients with anterior acute myocardial infarction treated by successful primary percutaneous coronary intervention (PCI). Results: Compared to rest, an additional STE >1 mm in one or more precordial ECG leads during exercise occurred in nine patients (69%), in the absence of symptoms. Conclusions: In acute myocardial infarction (MI) patients, treated by primary PCI and showing optimal coronary blood flow restoration at angiography, STE can still be induced by exercise in Q/QS wave ECG leads. This finding lends further support to the theory that exercise‐induced STE in this clinical context is unlikely to represent by itself transient myocardial ischemia or viability.
T‐Wave Morphology Parameters Based on Principal Component Analysis Reproducibility and Dependence on T−Offset Position
Authors: Extramiana Fabrice , Haggui Abdeddayem , Maison‐Blanche Pierre , Dubois Rémi , Takatsuki Seiji , Beaufils Philippe , Leenhardt Antoine 
Published: October 2007

Background: T‐wave morphology parameters based on principal component analysis (PCA) are candidate to better understand the relation between QT prolongation and torsades de pointes. We aimed to assess the repeatability and to determine the influence of T‐end position on PCA parameters. Methods: Digital ECGs recorded from 30 subjects were used to assess short term (5 minutes), circadian and long‐term (28 days) repeatability of PCA parameters. The T‐end cursor position was moved backward and forward (± 8 ms) from its optimal position. We calculated QRS‐T angle, PCA ratio, and T‐wave residuum (TWR). Results: At long‐term evaluation, coefficients of variation were 11.3 ± 9.9%, 11.7 ± 7.1%, and 23.0 ± 22.0% for the QRS‐T angle, PCA ratio, TWR, respectively. After moving the T‐end cursor, repeatability was 0.42 ± 0.2%, 1.00 ± 1.04%, 4.0 ± 4.2% for the same PCA parameters. Conclusions: T‐wave morphology parameters based on PCA are reproducible with the exception of TWR and QRS‐T angle. In addition, PCA is robust, showing only little dependence on T‐end cursor position. These data should be taken into account for safety pharmacology trials.
Assessing the outcome of community‐based psychiatric care: building a feedback loop from ‘real world’ health services research into clinical practice
Authors: Lasalvia A. , Ruggeri M. 
Published: October 2007

Objective: To describe the main characteristics of the South‐Verona Outcome Project (SVOP) and to focus on its overall conceptual framework, with specific reference to the following perspectives: i) integrating evidence‐based and practice‐based approaches; ii) involving service professionals in routine outcome assessment; and iii) involving service users in mental health outcome assessment.Method: A selective literature review of methodological and empirical papers addressing the relevance and usefulness of outcome research to routine clinical practice was performed.Results: Reviewed literature shows the need to integrate evidence‐based and practice‐based approaches and to involve service professionals in routine outcome assessment, by adopting a multiple perspective paradigm. Studies conducted in ‘real world’ health services indicate that the outcome of care is multifaceted and it can be perceived differently when different perspectives are taken into account. Such a complex picture can provide more comprehensive information on the effectiveness of care provided, to feed back positively into clinical practice.Conclusion: The SVOP design and its methodological background were demonstrated to be appropriate for a detailed and routine assessment of outcome in the ‘real world’ of mental health services.
Outcome of patients dropping out from community‐based mental health care: a 6‐year multiwave follow‐up study
Authors: Ruggeri M. , Salvi G. , Bonetto C. , Lasalvia A. , Allevi L. , Parabiaghi A. , Bertani M. , Tansella M. 
Published: October 2007

Objective:  To test three hypotheses: i) is dropping out of community mental health care due to dissatisfaction? ii) Do those who appropriately interrupt mental health care need any more help? iii) Do those who need treatment continue to receive it?Method:  A cohort from a Community Mental Health Service in Verona, Italy, was followed up for 6 years, interviewing patients at follow‐up who are both in contact and not in contact with the service.Results:  The main reason for dropping out was service dissatisfaction. Patients still in contact with the service were more often psychotic. Many patients no longer in contact had mild‐to‐moderate problems, especially anxiety and depression and some social disability. Patients out of contact rarely sought help from other agencies.Conclusion:  Comprehensive community mental health services seem to offer good continuity of mental health care to patients with psychosis, but dedicate less attention to patients with less severe problems. Some of these patients will go on experiencing a burden of symptoms and disability, over the years.
Applications and usefulness of routine measurement of patients’ satisfaction with community‐based mental health care
Authors: Ruggeri M. , Lasalvia A. , Salvi G. , Cristofalo D. , Bonetto C. , Tansella M. 
Published: October 2007

Objective:  This study was conducted within the framework of the South‐Verona Outcome Project (SVOP) in a sample of patients, with the full spectrum of psychiatric diagnoses, who are attending the South‐Verona Community‐based Mental Health Service (CMHS). It aims to exemplify some applications of routine measurements of service satisfaction and specifically: i) identify strengths and weaknesses, in the patients’ perspectives, of a ‘real world’ service; ii) monitor whether this specific service provides satisfactory care over 3 years and iii) identify if there are any patients’ characteristics that might be associated with service dissatisfaction.Method:  Service satisfaction was measured with the Verona Service Satisfaction Scale (VSSS) across three subsequent waves of the SVOP; frequency distributions of scores in the various VSSS domains were compared. The relationship between satisfaction with psychiatric care and a number of well‐established mental health indicators, including socio‐demographic, clinical and service intervention variables, was investigated using random‐effect models.Results:  The organization of service and the behaviour and manners of the professionals were the main service strengths. Weaknesses were identified in the physical layout of facilities, in the lack of involvement of relatives and in the information provided. Overall satisfaction was medium‐high, while subjects with longer duration of service contact and higher disability were the most dissatisfied. The predictors we examined, however, explained only modest percentages of variance.Conclusion:  Repeated, routine assessments of service satisfaction have provided a clear view of the South‐Verona CMHS’ strengths and weaknesses; this set of information was crucial for the continuous quality improvement process in the service.