bluuebunny/crossref_metadata_2025 huggingface dataset:
Two elderly patients with idiopathic normal pressure hydrocephalus diagnosed by head MRI and tap test
Authors: KITO Hisashi , MIYASHITA Mitsuhiro , TAKAHASHI Tohru , INUZUKA Sin , HANIHARA Tokiji , UCHIDA Naoko , AMANO Naoji , NAKAMURA Kazuya , HONGO Kazuhiro
Published: March 2006

Dementia, gait disturbance and urinary incontinence were noted in two elderly patients, and diagnosed as idiopathic normal pressure hydrocephalus (iNPH). Case 1 was a 79‐year‐old man in whom dementia symptoms appeared 2 years ago. Gait disturbance and urge incontinence of urine developed later, and the patient visited our hospital. Walking was wide‐based and frozen gait was noted at the time of visiting our hospital. The mini‐mental state examination (MMSE) score was 11. A head MRI detected expansion of the cerebral ventricles and sylvian fissures, and narrowing of the cerebral fissures and the subarachnoid space in the higher convexity region. The diagnosis of iNPH was made based on the clinical symptoms and imaging findings, and a shunt operation (cerebrospinal fluid shunt) was performed in the neurosurgery department. Gait disturbance and cognitive function slightly improved after the operation. Case 2 was an 81‐year‐old woman who had had brachybasia for 1 year, and swayed from side to side while walking. Since disorientation and urge incontinence transiently occurred, the patient visited our hospital. The MMSE score was 24. Head MRI findings were similar to those in case 1. The cerebrospinal tap test was performed, and walking improved in the 1‐week course observation. iNPH is not very well recognized, compared to secondary NPH, and is likely to be overlooked because differentiation from Alzheimer's disease and vascular dementia based on symptoms and imaging is difficult in elderly patients. As iNPH is treatable by accurate diagnosis and therapy, the accumulation of cases indicated for shunt operation may be necessary.
Necker cube copying ability in normal elderly and Alzheimer's disease. A community‐based study: The Tajiri project
Authors: SHIMADA Yoichi , MEGURO Kenichi , KASAI Mari , SHIMADA Masumi , ISHII Hiroshi , YAMAGUCHI Satoshi , YAMADORI Atsushi
Published: March 2006

Background:  The purpose of this study was to investigate the ability of normal elderly participants and patients with Alzheimer's disease to copy the Necker cube.

Method:  One hundred and seventy elderly participants were randomly selected from the town of Tajiri, northern Japan, and were classified into three groups based on the Clinical Dementia Rating (CDR): CDR 0, healthy; CDR 0.5, questionable dementia; and CDR 1 and 2, mild and moderate dementia. Dementia patients (CDR 1 and 2) met the criteria of probable AD of the NINCDS‐ADRDA. Using eight original criteria, we examined their ability to copy the Necker cube.

Results:  Most CDR 0 participants could at least succeed in copying a simple cube. About a half of the AD patients could not draw a three‐dimensional figure. Among the CDR 0.5 participants, we found a ‘two‐peak’ distribution.

Conclusion:  Copying the Necker cube may be one useful task for the detection of very mild Alzheimer's disease.
Physiologically‐Based Pharmacokinetic Modeling of Genistein in Rats, Part I: Model Development
Authors: Schlosser Paul M. , Borghoff Susan J. , Coldham Nicholas G. , David John A. , Ghosh Sujit K.
Published: March 2006

Genistein is a phytoestrogen—a plant‐derived compound that binds to and activates the estrogen receptor—occurring at high levels in soy beans and food products, leading to widespread human exposure. The numerous scientific publications available describing genistein's dosimetry, mechanisms of action, and identified or putative health effects in both experimental animals and humans make it ideal for examination as an example of endocrine‐active compound (EAC). We developed a physiologically‐based pharmacokinetic (PBPK) model to quantify the internal, target‐tissue dosimetry of genistein in adult rats. Complexities of the model include enterohepatic circulation, binding of both genistein and its conjugates to plasma proteins, and the multiple compartments used to describe transport through the bile duct and gastrointestinal tract. Other aspects of the model are simple perfusion‐limited transport to the tissue groups and first‐order rates of metabolism, uptake, and excretion. We describe here the model structure and initial calibration of the model by fitting to a large data set for Wistar rats. The model structure can be readily extrapolated to describe genistein dosimetry in humans or modified to describe the dosimetry of other phytoestrogens and phenolic EACs. The model does a fair job of capturing the pharmacokinetics. Although it does not describe the interindividual variability and we have not identified a single set of parameters that provide a good fit to the data for both oral and intravenous exposures, we believe it provides a good initial attempt at PBPK modeling for genistein, which can serve as a template for other phytoestrogens and in the design of future experiments and research that can be used to fill data gaps and better estimate model parameters.
Current Directions in Risk Research: New Developments in Psychology and Sociology
Authors: Taylor‐Gooby Peter , Zinn Jens O.
Published: March 2006

This article reviews the main approaches to risk in psychology and sociology and considers recent developments. It shows that research continues from a wide range of perspectives. Some developments in psychological thinking have recently acknowledged the importance of the cultural framing of risk perceptions and responses and the positive power of emotions to manage uncertainties, while some streams of work in sociology have moved toward more individualist approaches. These converging processes open opportunities for cross‐fertilization and for using insights from both disciplines in the development of research.
A Probabilistic Arsenic Exposure Assessment for Children Who Contact CCA‐Treated Playsets and Decks, Part 1: Model Methodology, Variability Results, and Model Evaluation
Authors: Zartarian Valerie G. , Xue Jianping , Özkaynak Halûk , Dang Winston , Glen Graham , Smith Luther , Stallings Casson
Published: March 2006

Concerns have been raised regarding the safety of young children who may contact arsenic residues while playing on and around chromated copper arsenate (CCA)‐treated wood playsets and decks. Although CCA registrants voluntarily canceled the production of treated wood for residential use in 2003, the potential for exposure from existing structures and surrounding soil still poses concerns. The EPA's Office of Research and Development developed and applied the probabilistic Stochastic Human Exposure and Dose Simulation model for wood preservatives (SHEDS‐Wood) to estimate children's absorbed dose of arsenic from CCA. Skin contact with, and nondietary ingestion of, arsenic in soil and wood residues were considered for the population of children in the United States who frequently contact CCA‐treated wood playsets and decks. Model analyses were conducted to assess the range in population estimates and the impact of potential mitigation strategies such as the use of sealants and hand washing after play events. The results show predicted central values for lifetime annual average daily dose values for arsenic ranging from 10−6 to 10−5 mg/kg/day, with predicted 95th percentiles on the order of 10−5 mg/kg/day. There were several orders of magnitude between lower and upper percentiles. Residue ingestion via hand‐to‐mouth contact was determined to be the most significant exposure route for most scenarios. Results of several alternative scenarios were similar to baseline results, except for the scenario with greatly reduced residue concentrations through hypothetical wood sealant applications; in this scenario, exposures were lower, and the soil ingestion route dominated. SHEDS‐Wood estimates are typically consistent with, or within the range of, other CCA exposure models.
A Probabilistic Arsenic Exposure Assessment for Children Who Contact Chromated Copper Arsenate (CCA)‐Treated Playsets and Decks, Part 2: Sensitivity and Uncertainty Analyses
Authors: Xue Jianping , Zartarian Valerie G. , Özkaynak Halûk , Dang Winston , Glen Graham , Smith Luther , Stallings Casson
Published: March 2006

A probabilistic model (SHEDS‐Wood) was developed to examine children's exposure and dose to chromated copper arsenate (CCA)‐treated wood, as described in Part 1 of this two‐part article. This Part 2 article discusses sensitivity and uncertainty analyses conducted to assess the key model inputs and areas of needed research for children's exposure to CCA‐treated playsets and decks. The following types of analyses were conducted: (1) sensitivity analyses using a percentile scaling approach and multiple stepwise regression; and (2) uncertainty analyses using the bootstrap and two‐stage Monte Carlo techniques. The five most important variables, based on both sensitivity and uncertainty analyses, were: wood surface residue‐to‐skin transfer efficiency; wood surface residue levels; fraction of hand surface area mouthed per mouthing event; average fraction of nonresidential outdoor time a child plays on/around CCA‐treated public playsets; and frequency of hand washing. In general, there was a factor of 8 for the 5th and 95th percentiles and a factor of 4 for the 50th percentile in the uncertainty of predicted population dose estimates due to parameter uncertainty. Data were available for most of the key model inputs identified with sensitivity and uncertainty analyses; however, there were few or no data for some key inputs. To evaluate and improve the accuracy of model results, future measurement studies should obtain longitudinal time‐activity diary information on children, spatial and temporal measurements of residue and soil concentrations on or near CCA‐treated playsets and decks, and key exposure factors. Future studies should also address other sources of uncertainty in addition to parameter uncertainty, such as scenario and model uncertainty.
Place, Culture, and the Social Amplification of Risk
Authors: Masuda Jeffrey R. , Garvin Theresa
Published: March 2006

This article investigates the role of culture in the social production of risks and risk communication surrounding industrial development in a region located at a rural‐urban interface. A case study examined a public consultation that was undertaken to inform local residents about an eco‐industrial development proposal being planned near Edmonton, Alberta, Canada. The research employed the social amplification of risk framework (SARF) to examine the relationships among culture, place, and socially constructed risk. A total of 44 in‐depth, semi‐structured interviews were carried out with 33 landowners (farmers, acreage owners), public officials (municipal politicians, administrators), journalists, and industry representatives. Analysis revealed that risk communication occurred in relation to situated experiences of place that were based on conflicting cultural worldviews. The research shows that place is a useful component of the SARF, providing a spatial explanation for why some people amplify, and others attenuate, risks in locally contentious environmental debates.
Why Do Neighbors Have Different Environmental Priorities? Analysis of Environmental Risk Perception in a Beirut Neighborhood
Authors: El‐Zein Abbas , Nasrallah Rola , Nuwayhid Iman , Kai Lea , Makhoul Jihad
Published: March 2006

Differences in environmental priorities within an urban neighborhood of Beirut are analyzed. The explanatory capabilities of five categories of contextual variables are compared: socioeconomic status, locality, health, behavior, and environmental beliefs. Semi‐structured interviews with key individuals in the community and residents were first conducted. Four environmental issues of concern were identified. A survey was carried out to identify the relative priority accorded by respondents to these four issues, and to measure variables likely to explain differences of opinion. Bivariate and multivariate logistic regression analyses were conducted for each of the four problems. The 99% confidence interval (CI) of the odds ratio (OR) was used as a test of significance. Respondents suffering from a respiratory disease (OR = 6.94, 99%CI = 1.54–31.25), those living in less crowded houses (OR = 4.88, 99%CI = 1.38–17.24), and those not living close to the neighborhood's industrial street (OR=5.26, 99%CI = 1.01–27.78) are significantly more likely to rank poor air quality first. Significant associations are found between poor water quality as first priority and nonpresence of a smoker in the household (OR = 6.12, 99%CI = 1.84–20.32) and perception of water salinity as a problem (OR = 7.46, 99%CI = 1.50–37.03). Males (OR = 6.94, 99%CI = 1.02–47.62) and tenants versus owners (OR = 10.49, 99%CI = 1.36–80.61) are significantly more likely to rank the residential‐industrial mix first. Socioeconomic variables retain their explanatory capability in the studied neighborhood, despite relatively small income disparities. Behavioral variables, such as smoking, may be causative factors of priorities. Analyzing relative priorities, rather than “concern” or lack of it, reveals more complex patterns of association. Identifying environmental‐perception divide lines can help develop a more inclusive and effective participatory environmental management.
Variability in Physical Constant Parameter Values from Standard Data Sources and the Implication of This Variability for Risk Analysis
Authors: Marino Dale J.
Published: March 2006

Physical property values are used in environmental risk assessments to estimate media and risk‐based concentrations. However, considerable variability has recently been reported with such values. To evaluate potential variability in physical parameter values supporting a variety of regulatory programs, eight data sources were chosen for evaluation, and chemicals appearing in at least four sources were selected. There were 755 chemicals chosen. In addition, chemicals in seven environmentally important subgroups were also identified for evaluation. Nine parameters were selected for analysis—molecular weight (MolWt), melting point (MeltPt), boiling point (BoilPt), vapor pressure (VP), water solubility (AqSOL), Henry's law constant (HLC), octanol‐water partition coefficient (Kow), and diffusion coefficients in air (Dair) and water (Dwater). Results show that while 71% of constituents had equal MolWts across data sources, <3% of the constituents had equivalent parameter values across data sources for AqSOL, VP, or HLC. Considerable dissimilarity between certain sources was also observed. Furthermore, measures of dispersion showed considerable variation in data sets for Kow, VP, AqSOL, and HLC compared to measures for MolWt, MeltPt, BoilPt, or Dwater. The magnitude of the observed variability was also noteworthy. For example, the 95th percentile ratio of maximum/minimum parameter values ranged from 1.0 for MolWt to well over 1.0E + 06 for VP, and HLC. Risk and exposure metrics also varied by similar magnitudes. Results with environmentally important subgroups were similar. These results show that there is considerable variability in physical parameter values from standard sources, and that the observed variability could affect potential risk estimates and perhaps risk management decisions.
Out of the Frying Pan into the Fire: Behavioral Reactions to Terrorist Attacks
Authors: Gigerenzer Gerd
Published: March 2006

A low‐probability, high‐damage event in which many people are killed at one point of time is called adread risk. Dread risks can cause direct damage and, in addition, indirect damage mediated though the minds of citizens. I analyze the behavioral reactions of Americans to the terrorist attacks on September 11, 2001, and provide evidence for the dread hypothesis: (i) Americans reduced their air travel after the attack; (ii) for a period of one year following the attacks, interstate highway travel increased, suggesting that a proportion of those who did not fly instead drove to their destination; and (iii) for the same period, in each month the number of fatal highway crashes exceeded the base line of the previous years. An estimated 1,500 Americans died on the road in the attempt to avoid the fate of the passengers who were killed in the four fatal flights.
Leukemia Attributable to Residential Magnetic Fields: Results from Analyses Allowing for Study Biases
Authors: Greenland Sander , Kheifets Leeka
Published: March 2006

Nearly every epidemiologic study of residential magnetic fields and childhood leukemia has exhibited a positive association. Nonetheless, because these studies suffer from various methodologic limitations and there is no known plausible mechanism of action, it remains uncertain as to how much, if any, of these associations are causal. Furthermore, because the observed associations are small and involve only the highest and most infrequent levels of exposure, it is believed that the public health impact of an effect would be small. We present some formal analyses of the impact of power‐frequency residential magnetic‐field exposure (as measured by attributable fractions), accounting for our uncertainties about study biases as well as uncertainties about exposure distribution. These analyses support the idea that the public health impact of residential fields is likely to be limited, but both no impact and a substantial impact remain possibilities in light of the available data.
Atrial Fibrillation Burden During the Post‐Implant Period After CRT Using Device‐Based Diagnostics
Authors: HÜGL BURKHARD , BRUNS HANS‐JÜRGEN , UNTERBERG‐BUCHWALD CHRISTINE , GROSSE ANETT , STEGEMANN BERTHOLD , LAUER BERNWARD , GELLER J. CHRISTOPH , GASPARINI MAURIZIO
Published: March 2006

Aims: Cardiac resynchronization therapy (CRT) is increasingly used in congestive heart failure (CHF) patients (with cardiac dyssynchrony). In addition to delivering therapy, CRT devices offer a variety of diagnostic tools for continuous long‐term monitoring of clinically relevant information (i.e., occurrence and duration of arrhythmia episodes).

Methods and Results: Eighty‐four patients with drug‐refractory CHF in NYHA‐class II–IV received a CRT device. The response to CRT was assessed by determining NYHA class at baseline and at 3 months follow‐up. Atrial fibrillation (AF) burden (defined as time of AF per day) was continuously measured by the device. A significant gradual reduction of AF burden (from 9.88 ± 12.61 to 4.20 ± 9.24 [hours/day]) and number of patients experiencing AF episodes (from 26 to 13) were observed during CRT.

Conclusions: (1) Diagnostic features for long‐term monitoring of physiological variables provide useful information on the state and course of AF and may improve disease management. (2) AF burden reduces over time during the first 3 months after CRT implantation.
Catheter Ablation of Right Ventricular Outflow Tract Tachycardia: Value of Defining Coronary Anatomy
Authors: VASEGHI MARMAR , CESARIO DAVID A. , MAHAJAN AMAN , WIENER ISAAC , BOYLE NOEL G. , FISHBEIN MICHAEL C. , HOROWITZ BARBARA NATTERSON , SHIVKUMAR KALYANAM
Published: March 2006

Introduction: Thermal damage to coronary arteries during catheter ablation has been previously reported. Coronary artery damage during LV outflow tract ventricular tachycardia is well recognized. However, the relationship of the coronary arteries to the RV outflow tract during catheter ablation has not been delineated. The purpose of this study was to define the relationship between the RV outflow tract and the coronary arteries utilizing arteriography, echocardiography, CT angiography, and gross anatomic pathology.

Methods: The relationship of the coronaries to the RV outflow tract was analyzed in three patients groups: Group 1: patients (n = 10) undergoing RV outflow tract ventricular tachycardia; Group 2: patients (n = 50) undergoing CT coronary angiography; Group 3: patients (n = 4) undergoing echocardiography during open heart surgery and intracardiac echocardiography (ICE) during catheter ablation of atrial fibrillation (n = 5).

Results: Group 1: The left main coronary artery was found to be 3.8 ± 1.2 mm from the right ventricular outflow tract in patients undergoing ablation. Group 2: The minimum distance between the left main, left anterior descending, and right coronary artery to the RV outflow tract endocardial wall were 4.1 ± 1.9 mm, 2.0 ± 0.6 mm, and 4.3 ± 1.9 mm (average ± SD) respectively. Group 3: During open heart surgery using echocardiography, the minimum distance between the left main and the right coronary artery to the RV outflow tract were 3.4 ± 0.35 mm and 2.0 ± 0.1 mm, respectively. The distance between the let main coronary artery and the RVOT by ICE was 3.8 ± 0.45 mm.

Conclusions: The major coronary arteries lie in close proximity of the RVOT, and their anatomic course should be taken into consideration during ablation of ventricular tachycardias arising from the RV outflow tract.
Extensive Ablation During Pulmonary Vein Antrum Isolation Has No Adverse Impact on Left Atrial Function: An Echocardiography and Cine Computed Tomography Analysis
Authors: VERMA ATUL , KILICASLAN FETHI , ADAMS JAMES R. , HAO STEVEN , BEHEIRY SALWA , MINOR STEPHEN , OZDURAN VOLKAN , CLAUDE ELAYI SAMY , MARTIN DAVID O. , SCHWEIKERT ROBERT A. , SALIBA WALID , THOMAS JAMES D. , GARCIA MARIO , KLEIN ALLAN , NATALE ANDREA
Published: March 2006

Background: Although pulmonary vein antrum isolation (PVAI) may cure atrial fibrillation (AF) and improve left atrial (LA) function, the effect of extensive LA ablation on LA function is not well known.

Objective: To assess the impact of PVAI on LA function remotely postablation.

Methods: Consecutive patients undergoing PVAI had either transthoracic (TTE) and transesophageal (TEE) echocardiography (n = 41) or cine EBCT (n = 26) performed preablation and 6 months postablation. Only patients with paroxysmal and persistent, but not permanent, AF were included. Imaging was done in sinus rhythm for all patients. LA diameter (LAD), LA systolic and diastolic areas, and left atrial fractional area change (LFAC) were assessed by TTE. Transmitral (TMF), left atrial appendage (LAA), and pulmonary venous (PVF) Doppler flows were measured by TEE. Peak A on TMF, LAA peak emptying velocity (LAAF), and peak A reversal (AR) on PVF were used as surrogates of LA contractile function. Peak S on PV flow was used as a surrogate of reservoir function. LA areas, volumes, and LA ejection fraction (LAEF) were measured from cine EBCT.

Results: Mean radiofrequency ablation time was 45 ± 21 minutes. All four PVs were isolated for all patients; there were no cases of PV stenosis. Echocardiography revealed a significant reduction in LAD and LA areas post‐PVAI. Both peak A and peak AR were also higher post, while other variables showed strong trends toward improvement. In the subset of patients with persistent AF, post‐PVAI improvements were seen in LA size, peak A, and even peak S (P = 0.04). Cine EBCT showed a significant decrease in both LA areas and volumes post‐PVAI. There was also a significant improvement in LAEF post‐PVAI from 17 ± 6% to 22 ± 5% (P = 0.01).

Conclusion: Extensive ablation during PVAI does not cause deterioration in LA function, and may cause long‐term improvement, especially in patients with higher AF burden.
Age, Size, and Lead Factors Alone Do Not Predict Venous Obstruction in Children and Young Adults with Transvenous Lead Systems
Authors: BAR‐COHEN YANIV , BERUL CHARLES I. , ALEXANDER MARK E. , FORTESCUE ELIZABETH B. , WALSH EDWARD P. , TRIEDMAN JOHN K. , CECCHIN FRANK
Published: March 2006

Background: Venous occlusion is a recognized complication of transvenous pacing, and lead cross‐sectional area indexed to body surface area (BSA) has been used to predict venous obstruction in children.

Objective: The aim of this study was to identify the risk factors and incidence of angiographic venous obstruction after transvenous lead implantation in both children and young adults.

Methods: Contrast venography was obtained in 85 of 90 consecutive patients undergoing repeat pacemaker or ICD procedures from 2002 to 2004 at a single cardiac center. Venograms were graded as complete venous obstruction, significant partial obstruction (>70% with collaterals), or patent.

Results: The cohort had a median age of 15.0 years at implant and was divided into two age groups: 3–12 years (n = 35) and 13 years and over (n = 50). After a median interval of 6.5 years, complete obstruction was seen in 11 of 85 patients (13%) and partial obstruction in another 10 patients (12%). No significant differences were seen in the incidence of obstruction between the two age groups although younger patients had a larger lead indexed to BSA ratio (6.82 vs 5.05, P = 0.005). There were no significant differences between obstructed and nonobstructed patients in relation to age, size, growth, or lead factors.

Conclusion: Transvenous lead systems implanted in young children have a similar incidence of venous occlusion compared to older patients. Furthermore, patient age, body size, and lead characteristics at implant do not clearly predict venous occlusion.
Left Ventricular Aneurysm in a Five‐Week‐Old Child
Authors: Pusca Sorin V. , Kanter Kirk R. , Fyfe Derek A. , Kim Dennis W. , Vincent Robert N.
Published: March 2006

Ventricular aneurysms in the pediatric population are rare and no standardized method of treatment exists. We present a case of left ventricular (LV) aneurysm in an infant, 5 weeks after a balloon aortic valvuloplasty for congenital aortic stenosis.
Pre‐ and Postoperative Quantitation of Right Ventricular Tissue Doppler Velocities in Infants with Hypoplastic Left Heart Syndrome
Authors: Christensen Douglas , Cardis Brian , Mahle William , Lewis Reginald , Huckaby Jeryl , Favaloro‐Sabatier Jennifer , Fyfe Derek
Published: March 2006

Background: The purpose of this study was to use tissue Doppler imaging (TDI) to serially quantitate initial and preoperative right ventricular (RV) TDI velocities and compare them to postoperative RV TDI velocities as measures of RV function in newborns with hypoplastic left heart syndrome (HLHS). Methods: Twelve consecutive patients were prospectively studied with diagnosis of HLHS. Systolic (Sw) and early diastolic (Ew) velocities were recorded at the tricuspid annulus and the ventricular septum at (1) admission, (2) immediately preoperative, and (3) during recovery. All patients were treated preoperatively with prostaglandins (PGE). Velocities were compared using repeated measure analysis of variance. Results: Mean age at diagnosis was 1 day (0–4 days). Time from diagnosis to surgery was 4 days (1–9 days), age at surgery 5.3 days (2–10 days), and time from surgery to postoperative echo 12.3 days (5–19 days). Tricuspid annular and septal systolic velocities increased from admission to preoperative. Both tricuspid Sw and Ew and septal Sw velocities decreased postoperatively. No significant changes occurred in the ventricular septal diastolic (Ew) velocities from admission to preoperative. Conclusion: These data indicate that following the institution of PGE and initial medical and ventilatory management, there is an increase in RV annular and septal systolic velocities from the initial to the preoperative period and that these indices as well as RV annular diastolic velocities decline significantly postoperatively. Initial septal diastolic velocities were severely abnormal and did not significantly change pre‐ and postoperatively. These data may have significance for both postoperative and subsequent long‐term RV function.
Assessment of the Tilting Properties of the Human Mitral Valve during Three Main Phases of the Heart Cycle: An Echocardiographic Study
Authors: Vanhercke Daniel , Claessens Tom , Vandekerckhove Hans , Van Tricht Ilse , Segers Patrick , Verdonck Pascal
Published: March 2006

Rationale and Objectives: In experimental models of the left heart, the mitral valve (MV) is commonly implanted perpendicular to a central axis of the apex/MV. To adapt this to a more correct anatomical model, as well as for further studies of the left ventricle, we created a database of implantation angles of the MV and annulus during three main phases of the heart cycle, based on standard cardiac ultrasound measurements. Materials and Methods: Twenty‐eight patients were studied with the standard cardiac ultrasound equipment. From the apical echo window, an anteroposterior (AP) plane and a perpendicular commisure‐commisure (CC) plane were generated during three critical moments in the heart cycle: systole (S); diastole early filling (E); and diastole late filling (A). In both planes, the angles between the annular plane and each mitral leaflet, as well as the angle between a theoretical longitudinal axis through the apex and center of the MV orifice and the mitral annulus plane, were measured with a custom‐made application of Matlab R14. Results: We observed an inclination of the angle mitral annulus/central left ventricle axis, with its lowest point in the direction of the aortic valve (AP plane) of 85°± 7° in systole (S), 88°± 8° in early diastole (E), and 88°± 7° in late diastole (A). In the CC plane, we observed an almost horizontal implantation of 91°± 5° in systole (S), 91°± 8° in early diastole (E), and 91°± 7° in late diastole (A).
Hepatopulmonary Syndrome and Right Ventricular Diastolic Functions: An Echocardiographic Examination
Authors: Karabulut Aziz , Iltumur Kenan , Yalcin Kendal , Toprak Nizamettin
Published: March 2006

Aim: Liver functions are affected in the course of cardiac diseases, and similarly, liver diseases affect cardiac functions. Many studies in the literature have shown that left ventricular systolic and/or diastolic dysfunction may develop during chronic liver disease. However, there are limited studies investigating right ventricular functions during chronic liver diseases. Methods: A total of 84 patients who had no systolic and/or diastolic dysfunction in the left ventricle (LV) were evaluated; 46 patients with liver cirrhosis; 10 (21.74%) cirrhotic patients with hepatopulmonary syndrome (HPS) (group 1), 36 (78.26) cirrhotic patients without HPS (group 2), and 38 healthy individuals were treated as control. Results: Right ventricular diastolic dysfunction was determined in all patients of group 1 (100%), 26 of group 2 (72.22 %), and 4 of the controls (10.52%) (P < 0.05). Tricuspid deceleration time (dt) was significantly different between the groups (P < 0.05). In addition, right atrium (RA) diameters, right ventricle (RV) diameters, and RV wall thickness were significantly different between the groups (P < 0.05). Pulmonary artery pressure (P < 0.05) and pulmonary vascular resistance (P < 0.05) were also seen to be higher in group 1 than those in group 2 and control group. Conclusions: Right ventricular diastolic dysfunction rate is high in chronic liver diseases. In the presence of HPS, right ventricular diastolic dysfunction is more remarkable in patients than those without HPS. Right ventricular diastolic dysfunction may result in dilatation and hypertrophy in the right heart.
Bedside Percutaneous Transseptal Mitral Commissurotomy under Sole Transthoracic Echocardiographic Guidance in a Critically Ill Patient
Authors: Trehan Vijay K. , Nigam Arima , Mukhopadhyay Saibal , Yusuf Jamal , UmaMahesh C.R. , Gupta Mohit D. , Girish Menahalli Palleda , Sharma Manish
Published: March 2006

Percutaneous transvenous mitral commissurotomy is an effective and safe alternative to surgical treatment, in selected patients of rheumatic mitral stenosis. It is usually performed under fluoroscopic guidance in the catheterization laboratory. We report the successful performance of emergency mitral commissurotomy by the Inoue balloon at bedside under sole transthoracic echocardiographic guidance in a critically ill patient.
A Different Intracardiac Mass: Retained Sponge
Authors: Imren Yildirim , Tasoglu Irfan , Ozkose Zerrin
Published: March 2006

We report a case involving a surgical sponge retained following an aortic valve replacement. The surgical sponge was placed into the left ventricle to protect calcified debris from falling down into the left ventricular cavity. However, the sponge was forgotten and left inside the patient. We identified the retained surgical sponge by transesophageal echocardiography, which was performed because of a difficulty in weaning the patient from the cardiopulmonary bypass.
Intracardiac Echo Guided Valvuloplasty of a Stenotic Tricuspid Prosthetic Valve in a Patient with Idiopathic Hypereosinophilic Syndrome
Authors: Burstow Darryl J. , West Malcolm L. , Walters Darren L.
Published: March 2006

A 52‐year‐old male with idiopathic hypereosinophilic syndrome (HES) was transferred to our institution following the development of acute respiratory failure and shock. He had previously undergone tricuspid valve replacement with bioprosthetic valves on two occasions: the initial surgery for severe native tricuspid valve stenosis and the redo surgery for severe prosthetic valve stenosis and regurgitation. Conventional imaging assessment using transoesophageal echocardiography was suboptimal and comprehensive assessment of prosthetic valve function was aided by the use of intracardiac echocardiography (ICE). ICE provided high quality 2D imaging of the prosthesis demonstrating thrombus‐like material coating the inner surfaces of the prosthetic valve stents effectively forming a tunnel‐like obstruction. Unusual hemodynamics secondary to severe tricuspid stenosis were demonstrated by CW Doppler with intermittent “signal fusion” resulting from blunted respiratory variation in the markedly elevated right atrial pressure relative to right ventricular pressure. Successful balloon valvuloplasty was performed with ICE proving highly valuable in guiding balloon position as well as monitoring the efficacy of the subsequent inflations.
Prediction of Left Main Coronary Artery Obstruction by 12‐Lead Electrocardiography: ST Segment Deviation in Lead V6 Greater than or Equal to ST Segment Deviation in Lead V1
Authors: Mahajan Nitin , Hollander Gerald , Thekkoott Deepak , Temple Brian , Malik Bilal , Abrol Sunil , Yens David , Shani Jacob , Lichstein Edgar
Published: March 2006

Background: Acute coronary syndrome (ACS) resulting from culprit lesion in left main coronary artery (LMCA) can cause rapid hemodynamic deterioration. It is important to identify these patients early to facilitate timely revascularization. ST segment elevation in aVR greater than or equal to V1 (aVR‐V1≥ 0) has been suggested as a sensitive predictor of LMCA disease. As a result of balanced forces, we hypothesized that ST deviation in V6 greater than or equal to ST deviation in V1 (V6‐V1≥ 0) might be a good determinant of LMCA disease.

Methods: We compared admission 12‐lead ECGs of ACS resulting from culprit LMCA lesion (n = 75, group I) with ACS resulting from culprit left anterior descending lesion (n = 81, group II). Group I was selected over a period of 10 years. We compared V6‐V1≥ 0 to aVR‐V1≥ 0 in both groups. We also looked at ratios of ST deviations in V6,V1 (V6/V1≥ 1) and aVR,V1 (aVR/V1≥ 1) in patients where ST segment in V1 was not isoelectric (group I = 54 and group II = 55).

Results: ST deviation in V6 was significantly greater in group I as compared to group II (P < 0.001). The reliabilities of V6‐V1≥ 0, V6/V1≥ 1, aVR‐V1≥ 0, and aVR/V1≥ 1 in predicting LMCA disease were determined.

Conclusion: This is the largest series of ECG analysis on ACS resulting from culprit LMCA lesion. V6‐V1≥ 0 and V6/V1≥ 1 were more sensitive in predicting LMCA as culprit vessel in comparison to previously reported greater ST segment elevation in aVR than V1.
Triggers of Sustained Monomorphic Ventricular Tachycardia Differ Among Patients with Varying Etiologies of Left Ventricular Dysfunction
Authors: Rosman Jonathan , Hanon Sam , Shapiro Michael , Evans Steven J , Schweitzer Paul
Published: March 2006

Background: The mechanisms underlying the initiation of sustained ventricular tachycardia (VT) have not been fully elucidated. The extent to which reentry, abnormal automaticity, and triggered activity play a role in VT differs depending on the etiology of left ventricular dysfunction. By analyzing electrograms from implantable cardioverter defibrillator (ICD), we sought to determine whether there were differences in VT initiation patterns between patients with ischemic and nonischemic cardiomyopathy.

Methods: We analyzed ICD electrograms in patients with ejection fractions < 40% who had sustained VT over a 27‐month period. The trigger for VT onset was classified as a ventricular premature beat (VPB), supraventricular tachycardia, or of “sudden onset.” The baseline cycle length, VT cycle length, coupling interval, and prematurity ratio were recorded for each event. The prematurity ratio was calculated as the coupling interval of the VT initiator divided by the baseline cycle length.

Results: Sixty‐three VT events in 14 patients met the inclusion criteria. A VPB initiated the VT in 58 episodes (92%), 1 episode (2%) was initiated by a supraventricular tachycardia, and 4 episodes (6%) were sudden onset. The prematurity ratio was significantly higher (P < 0.05) in patients with ischemic cardiomyopathy (0.751 ± 0.068) as compared to patients with nonischemic cardiomyopathy (0.604 ± 0.139).

Conclusion: VPBs initiated most sustained VT episodes. A significantly higher prematurity ratio was observed in the ischemic heart disease group. This may represent different mechanisms of VT initiation in patients with ischemic versus nonischemic heart disease.
Atrial Near‐Field and Ventricular Far‐Field Analysis by Automated Signal Processing at Rest and During Exercise
Authors: Eberhardt Frank , Bonnemeier Hendrik , Lipphardt Martin , Hofmann Ulrich G. , Schunkert Heribert , Wiegand Uwe K. H.
Published: March 2006

Introduction: Sophisticated monitoring of atrial activity is a prerequisite for modern pacemaker therapy. Ideally, near‐fields and ventricular far‐fields ought to be distinguished by beat‐to‐beat template analysis of the atrial signal. A prerequisite is that atrial signals are stable under different conditions.

Methods and Results: A Matlab routine was developed to analyze atrial electrograms of 23 patients at least 3 months after implantation of a dual chamber pacemaker under several conditions including at rest, bipolar at rest, in an upright position, during treadmill exercise, and postexercise. A near‐field and far‐field template was created and amplitudes, widths, and slew rates were measured. In bipolar configuration, near‐field amplitude at rest was 3.04 ± 0.94 mV (unipolar)/3.36 ± 1.0 mV (bipolar) versus 3.18 ± 1.0 mV (bipolar) at peak exercise. Far‐field amplitude at rest was 1.66 ± 1.18 (unipolar)/0.47 ± 0.27 mV (bipolar) and 0.41 ± 0.21 mV (bipolar) at peak exercise (n.s. for bipolar measurements). No overall significant changes were observed for near‐ and far‐field widths and slew rates during exercise. Shorter tip‐ring distances of the atrial bipole, lead position, and the presence of sinus node disease did not have any impact on overall near‐ and far‐field signal characteristics. Intraindividual differences between rest and peak exercise were moderate (range: near‐field +0.15 to −0.54 mV; range: far‐field +0.05 to −0.18 mV).

Conclusions: Atrial near and far fields can be automatically classified and quantified by automated signal processing. Signals did not change during exercise or change of posture. This is a prerequisite for the implementation of beat‐to‐beat template analysis into pacemakers.
QT Dispersion Increases with Aging
Authors: Yavuz Bunyamin , Deveci Onur Sinan , Yavuz Burcu Balam , Halil Meltem , Aytemir Kudret , Cankurtaran Mustafa , Kabakci Giray , Kaya Baris , Ariogul Servet , Oto Ali
Published: March 2006

Background:Age‐related changes in cardiovascular system are well‐known. Arrhythmias in elderly patients constitute most of the urgencies, consultations, or hospitalizations. QT dispersion (QTd) is a simple noninvasive arrhythmogenic marker to demonstrate the electrical instability of the heart. The aim of this study was to investigate how QTd changes with increasing age by calculating the QTd in the elderly and younger subjects.

Methods:One hundred and forty‐six consecutive subjects (62 males and 84 females; age range: 18–82 years) were enrolled in the study. Sixty‐seven of the subjects were 65 years and over (mean age, 70 ± 4), 79 were younger than 65 (mean age, 37 ± 11). A 12‐lead ECG was recorded. The longest and the shortest QT intervals were measured manually on these ECG recordings. QTd was calculated from the formula, QTd = QTmax − QTmin.

Results:Demographic features were similar between the two groups. QTd of the elderly group was found to be significantly higher than the younger group (35.6 ± 15.6 in elderly, 24.2 ± 12.4 in younger group, P < 0.001). A positive relationship was found between QTd and age (r = 0.415, P < 0.001). QTd was greater in female than in male (31.9 ± 16.7 ms vs 26.0 ± 11.3 ms, respectively, P = 0.018).

Conclusions:Our study shows that QTd increases with advancing age. We think that long‐term follow‐up of these patients would be useful to show if there is any relationship between the clinical outcomes and the increase in QTd.
Fragmented Left Sided QRS in Absence of Bundle Branch Block: Sign of Left Ventricular Aneurysm
Authors: Reddy Chatla V. R. , Cheriparambill Kuruvilla , Saul Barry , Makan Majesh , Kassotis John , Kumar Awaneesh , Das Mithilesh Kumar
Published: March 2006

Background: A left ventricular aneurysm (LVA) occurs between 3.5% and 9.4% of all cases of acute myocardial infarction. A fragmented left sided QRS (RSR` pattern or its variant RSr`, rSR`, or rSr`) without evidence of bundle branch block (QRS duration ≤120 ms) on the ECG may be associated with a significant myocardial scar, which is the characteristic of a LVA. We, therefore, postulate that fragmented QRS (RSR` pattern or its variant) in the left sided leads (I, aVL, V3 to V6) may be a useful sign of LVA.

Methods: ECGs of 110 consecutive patients with LVA documented by left ventricular angiography (30° right anterior oblique view) was compared with 220 patients without LVA (110 patients with and 110 patients without coronary artery disease (CAD)), who were evaluated for CAD by symptoms and signs.

Results: The sensitivity of the fragmented QRS for identification of LVA was 50% (55 of 110 patients) and specificity was 94.6% (209 of 220). Within the study population, the positive predictive value of the fragmented QRS for LVA was 83.3% (55 of 66) and the negative predictive value was 79.2% (209 of 264). Based on the range of prevalence of LVA in postmyocardial infarction population (3.5–9.4%) and on observed sensitivity and specificity, the positive predictive value of fragmented QRS for LVA after infarction can be estimated at 29–53% and the negative predictive value can be estimated at 95–98%.

Conclusion: The sensitivity of fragmented QRS in left precordial leads for LVA was only 50%, whereas the specificity was 94.5%. It has a relatively low to moderate positive predictive value and high negative predictive value.
Patterns of Atrial Fibrillation After Coronary Artery Bypass Surgery
Authors: Tamis‐Holland Jacqueline E. , Kowalski Marcin , Rill Velisar , Firoozi Kamran , Steinberg Jonathan S.
Published: March 2006

Background: Atrial fibrillation (AF) is the most common arrhythmia occurring in patients after coronary artery bypass surgery (CABG). The purpose of this study was to determine whether AF characteristics were independently associated with postoperative length of stay (LOS).

Methods: Two hundred ninety consecutive post‐CABG patients were examined through a detailed chart review. Baseline, intraoperative, and postoperative variables and the characteristics of AF were recorded. AF episodes were divided into single episodes lasting less than 24 hours (short‐lived AF) and recurrent or prolonged ≥24 hours of AF (recurrent/prolonged AF).

Results: AF occurred in 94 (32.4%) patients. Twenty‐six (27.7%) of AF patients had short‐lived AF, and 68 (72.3%) of AF patients had recurrent/prolonged AF. Patients with recurrent/prolonged AF were older (P < 0.001) and more likely to have a history of prior AF (P < 0.001) relative to the other groups. Short‐lived AF did not prolong LOS (7.2 ± 2.1 days) relative to patients without AF (7.5 ± 3.9 days), whereas recurrent/prolonged AF significantly prolonged LOS (10.4 ± 6.1 days, P < 0.001). Multivariate analysis identified postoperative complications, recurrent/prolonged AF, age, and digoxin use as independent predictors of LOS. Recurrent/prolonged AF contributed an additional 1.1 days to LOS after adjusting for baseline clinical differences.

Conclusions: There are heterogenous patterns of AF after cardiac surgery. A substantial minority of AF is short‐lived and isolated with no impact on LOS; however, recurrent or prolonged AF significantly affects LOS.
An Evaluation of the Impact of Oral Magnesium Lactate on the Corrected QT Interval of Patients Receiving Sotalol or Dofetilide to Prevent Atrial or Ventricular Tachyarrhythmia Recurrence
Authors: McBride Brian F. , Min Bokyung , Kluger Jeffrey , Guertin Danette , Henyan Nickole N. , Coleman Craig I. , Silver Burton B. , White C. Michael
Published: March 2006

Background: Intravenous magnesium reduces the QTc interval of patients receiving ibutilide. Whether oral magnesium can reduce the QTc interval associated with oral sotalol and dofetilide is not known. This study was undertaken to evaluate the impact of oral magnesium on the QTc interval and whether an inherent intracellular magnesium deficiency exists among patients with arrhythmias.

Methods: Participants receiving sotalol or dofetilide for atrial or ventricular arrhythmias were randomized to receive magnesium l‐lactate (504 mg elemental magnesium daily, Niche Pharmaceuticals, Roanoke, TX) or placebo for 48 hours. A 12‐lead electrocardiogram (ECG) was obtained at baseline, 3 hours, and 51 hours after dosing to correspond to the Tmax after oral ingestion. The QTc interval was measured from the ECGs and compared between groups. Intracellular magnesium concentrations were determined by energy‐dispersive x‐ray analysis at baseline and 51 hours after dosing (Intracellular Diagnostics, Inc., Foster City, CA).

Results: The QTc interval reductions from baseline were greater in the magnesium group than placebo at 3 and 51 hours (P = 0.015 and P < 0.001, respectively). Sixty‐three percent of patients (regardless of experimental group) had baseline intracellular magnesium concentrations below the normal reference range of 33.9–41.9 mEq/IU, with an average level of 32.6 ± 2.2 mEq/IU.

Conclusions: Oral magnesium l‐lactate raises intracellular magnesium concentrations and lowers the QTc interval of patients receiving sotalol or dofetilide.