bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulation of gap junctions by nitric oxide contributes to the anti‐arrhythmic effect of sodium nitroprusside?
Authors: Gönczi Márton , Papp Rita , Kovács Mária , Seprényi György , Végh Ágnes
Published: February 2009

Background and purpose:  Nitric oxide (NO) donors provide a preconditioning‐like anti‐arrhythmic protection in the anaesthetized dog. As NO may modulate gap junction (GJ) function, the present study investigated whether this anti‐arrhythmic effect is due to a modification of GJs by NO, derived from the NO donor sodium nitroprusside (SNP).

Experimental approach:  In chloralose‐urethane‐anaesthetized, open‐chest dogs, either saline (controls; n= 11) or SNP (0.2 µg·kg−1·min−1; n= 10) was infused at a rate of 0.5 mL·min−1 by the intracoronary route. The infusions were started 20 min prior to and maintained throughout the entire 60 min occlusion period of the left anterior descending coronary artery. The severity of ischaemia and of arrhythmias, tissue electrical impedance and permeability, as well as the phosphorylation of connexin43, were assessed.

Key results:  Compared with the controls, SNP infusion markedly suppressed the total number of ventricular premature beats (666 ± 202 vs. 49 ± 18; P < 0.05), and the number of ventricular tachycardiac episodes (8.1 ± 2.3 vs. 0.2 ± 0.1; P < 0.05) without significantly modifying the incidence of ventricular tachycardia or ventricular fibrillation. The severity of ischaemia (epicardial ST‐segment changes, inhomogeneity of electrical activation) and tissue electrical impedance changes were significantly less in the SNP‐treated dogs. SNP improved GJ permeability and preserved the phosphorylated form of connexin43.

Conclusion and implications:  The anti‐arrhythmic protection resulting from SNP infusion in the anaesthethized dog may, in part, be associated with the modulation of gap junctional function by NO.
CHF5074, a novel γ‐secretase modulator, attenuates brain β‐amyloid pathology and learning deficit in a mouse model of Alzheimer's disease
Authors: Imbimbo BP , Hutter‐Paier B , Villetti G , Facchinetti F , Cenacchi V , Volta R , Lanzillotta A , Pizzi M , Windisch M
Published: February 2009

Background and purpose:  We evaluated the effects of 1‐(3′,4′‐dichloro‐2‐fluoro[1,1′‐biphenyl]‐4‐yl)‐cyclopropanecarboxylic acid (CHF5074), a new γ‐secretase modulator, on brain β‐amyloid pathology and spatial memory in transgenic mice expressing the Swedish and London mutations of human amyloid precursor protein (hAPP).

Experimental approach:  Sixty 6‐month‐old hAPP mice were treated for 6 months with CHF5074 or ibuprofen (375 ppm in the diet) or standard diet. Twenty‐one wild‐type mice received standard diet.

Key results:  Compared with transgenic controls, CHF5074 treatment significantly reduced the area occupied by plaques in cortex (P = 0.003) and hippocampus (P = 0.004). The number of plaques were also reduced by CHF5074 in both cortex (P = 0.022) and hippocampus (P = 0.005). Plaque‐associated microglia in CHF5074‐treated animals was lower than in transgenic controls in cortex (P = 0.008) and hippocampus (P = 0.002). Ibuprofen treatment significantly reduced microglia area in cortex and hippocampus but not β‐amyloid burden. On the last day of the Morris water maze, transgenic controls performed significantly worse than the non‐transgenic animals and the CHF5074‐treated transgenic mice, on the swimming path to reach the hidden platform. Ibuprofen‐treated animals did not perform significantly better than transgenic controls.

Conclusions and implications:  Chronic CHF5074 treatment reduced brain β‐amyloid burden, associated microglia inflammation and attenuated spatial memory deficit in hAPP mice. This novel γ‐secretase modulator is a promising therapeutic agent for Alzheimer's disease.
Oral rapamycin attenuates inflammation and enhances stability of atherosclerotic plaques in rabbits independent of serum lipid levels
Authors: Chen Wen Qiang , Zhong Lin , Zhang Lei , Ji Xiao Ping , Zhang Mei , Zhao Yu Xia , Zhang Cheng , Zhang Yun
Published: February 2009

Background and purpose:  Atherosclerotic plaque rupture and thrombosis are the main cause of acute coronary syndrome. The study was aimed to test the hypothesis that oral administration of rapamycin may attenuate inflammation, inhibit progression and enhance stability of atherosclerotic plaques.

Experimental approach:  Thirty New Zealand rabbits were subjected to balloon‐induced endothelial injury of the abdominal aorta and were fed a diet of 1% cholesterol for 20 weeks. From week 9 to week 20, the animals were treated with oral rapamycin (0.5 mg·kg−1·day−1; group A), oral simvastatin (5 mg·kg−1·day−1; group B) and no drugs (group C). At the end of week 20, all rabbits were challenged with injection of Chinese Russell's viper venom and histamine. Serological, ultrasonographic, pathological, immunohistochemical and gene expression studies were performed.

Key results:  Rapamycin significantly increased the thickness of the fibrous caps and decreased plaque vulnerability index in group A rabbits. Serum lipid levels were higher whereas plaque burden was lower in group A than in group B (P < 0.05). The incidence of plaque rupture in group A (0%) and group B (0%) was significantly lower than that in group C (56.0%, P < 0.05).

Conclusions and implications:  Oral administration of rapamycin effectively attenuated inflammation, inhibited progression and enhanced stability of atherosclerotic plaques in rabbits, without altering serum lipid levels. Our findings suggest a novel approach to the treatment of atherosclerosis.
Experiences of intensive care unit diaries: ‘touching a tender wound’
Authors: Engström Åsa , Grip Kristin , Hamrén Mikaela
Published: February 2009

Aim:  The aim of this study was to describe peoples’ experiences of a personal diary written when they were critically ill and receiving care in an intensive care unit (ICU).

Background:  In some ICUs, diaries are written by the ICU staff and close relatives of those who are critically ill and mechanically ventilated, but there is a lack of studies that focus on the experiences of the formerly critically ill of personal diaries written when in an ICU.

Methods:  Qualitative personal interviews were conducted with nine people who were formerly critically ill. The interview texts were analysed using qualitative content analysis.

Findings:  From the analysis of the data, one theme emerged – touching a tender wound, with four categories: being afraid and being deeply touched, appreciating close relatives’ notes, a feeling of unreality and gaining coherence. The participants were deeply touched when they read the diary for the first time. Parts of it were experienced as unreal, as if they were reading about someone else. The diary provided necessary knowledge about what had happened during the time when the participants were critically ill and from which they had only fragmented or no memories at all. Even though it aroused strong feelings, reading the diary was experienced as an important support for a long time after their stay in the ICU. Experiencing that one was not fully aware of what had happened and then reading about oneself being critically ill and about one’s close relatives’ experiences was interpreted as touching a tender wound.

Conclusions and relevance to clinical practice:  It is suggested that a diary may be a tool that can help formerly critically ill people to gain a sense of coherence concerning their critical illness experience, but reading it can be painful and demanding.
Advancing practice in critical care: a model of knowledge integration
Authors: Christensen Martin
Published: February 2009

Aim: The aim of this paper was to discuss the potential development of a conceptual model of knowledge integration pertinent to critical care nursing practice. A review of the literature identified that reflective practice appeared to be at the forefront of professional development.

Background: It could be argued that advancing practice in critical care has been superseded by the advanced practice agenda. Some would suggest that advancing practice is focused on the core attributes of an individual’s practice, which then leads onto advanced practice status. However, advancing practice is more of a process than identifiable skills and as such is often negated when viewing the development of practitioners to the advanced practice level. For example, practice development initiatives can be seen as advancing practice for the masses, which ensures that practitioners are following the same level and practice of care. The question here is, are they developing individually?

Relevance to clinical practice: What this paper presents is that reflection may not be best suited to advancing practice if the individual practitioner does not have a sound knowledge base both theoretically and experientially. The knowledge integration model presented in this study uses multiple learning strategies that are focused in practice to develop practice, e.g. the use of work‐based learning and clinical supervision. To demonstrate the models application, an exemplar of an issue from practice shows its relevance from a practical perspective.

Conclusions: In conclusion, further knowledge acquisition and its relationship with previously held theory and experience will enable individual practitioners to advance their own practice as well as being a resource for others.
Home‐Based Injury Prevention Practices Used by Mothers of Mexican Descent Living in San Antonio, TX
Authors: Gallagher Martina R. , Reifsnider Elizabeth , Gill Sara
Published: February 2009

ABSTRACT
Purpose: To describe the home‐based injury prevention practices used by low‐income mothers of Mexican descent with their preschool children.

Design and sample: A descriptive qualitative study with convenience sampling of mothers (n=9) who are of Mexican descent and have preschool children.

Method: Data collection consisted of ethnographic interviews supplemented by focused home observations.

Results: 2 themes emerged from the data: the spectrum of physical proximity and the use of injury prevention technology. The spectrum of physical proximity reflected the degree of physical closeness (i.e., supervising children, watching children closely, and being after children) that the mothers used to manage injury risk in their children. Children who were perceived as curious or restless, or too young were judged by the mothers as being prone to injury and requiring more maternal physical closeness. The participants used the injury prevention technology recommended by the experts despite their limited economic resources. However, this group of mothers used the spectrum of physical proximity as the main tool to prevent child injuries in their home.

Conclusion: These findings provide an insight into the attitudes and behaviors of low‐income, Mexican mothers toward injury prevention in the home. Awareness of these attitudes and behaviors will allow for the creation of interventions that take into account this maternal perspective.
Teacher Characteristics and Knowledge of Asthma
Authors: Getch Yvette Q. , Neuharth‐Pritchett Stacey
Published: February 2009

ABSTRACT
Objectives: We explored the characteristics of teachers and their knowledge of asthma and its management in elementary and middle‐school classrooms.

Design: Teachers completed the Georgia Public School Teachers' Asthma Knowledge and Perception Survey.

Sample: The study sample consisted of 593 elementary (n=291) and middle‐school teachers (n=302) from Georgia.

Methods: Participants were asked to complete a survey on asthma knowledge. Data were analyzed to examine differences among elementary‐ and middle‐school teachers, teachers' level of educational attainment, teachers' chronic medical condition, and teachers' asthma status.

Results: Middle‐school teachers were more knowledgeable about asthma than elementary teachers. No differences were found among teachers based on their level of educational attainment. Most teachers strongly agreed that asthma could not be cured, but managed. Teachers with chronic illnesses were more knowledgeable than those without a chronic illness and teachers who had asthma were the most knowledgeable about asthma and its management.

Conclusions: Teacher knowledge of asthma and its management was low among all teachers regardless of educational attainment, health status, or whether teachers taught at elementary or middle‐school levels.
The Relationship Between Children's Locus of Control and Their Anticipatory Anxiety
Authors: Li Ho Cheung William , Chung Oi Kwan Joyce
Published: February 2009

ABSTRACT
Objectives: This study investigated the relationship between children's locus of control and their state anxiety scores, and determined whether children's locus of control could predict their state anxiety scores before academic examinations.

Design: A test‐retest within subjects design was used.

Sample: 519 school children were invited to participate in the study.

Measurements: Participants were asked to respond to the Chinese version of the Nowicki‐Strickland locus of control scale and state anxiety scale for children in stressful and nonstressful situations. The data were collected in 2005.

Results: There were significant strong positive correlations between the state anxiety and locus of control scores in the period before academic examinations. Multiple regression analysis showed that the Nowicki‐Strickland locus of control score was a good predictor of children's state anxiety in a stressful situation.

Conclusions: This study supports the use of the Nowicki‐Strickland locus of control scale as a screening tool to identify school children who are most likely to exhibit high levels of anxiety before academic examinations. Understanding children's locus of control in advance is a necessary step toward designing appropriate interventions to reduce their stress and bolster their coping mechanisms.
Providers' Experiences with Young People's Cognitive Representations and Emotions Related to the Prevention and Treatment of Sexually Transmitted Infections
Authors: Royer Heather R. , Zahner Susan J.
Published: February 2009

ABSTRACT
Objective: The Common Sense Model (CSM) was used as the organizing framework to examine providers' experiences with young people's cognitive representations and emotions related to the prevention and treatment of sexually transmitted infections (STIs). This study was conducted to develop insights into potential avenues for enhancing the effectiveness of STI education and counseling for young people.

Design: This was a qualitative investigation using semi‐structured focus group interviews.

Sample: The 5 focus groups were comprised of 30 providers of STI education and counseling: public health nurses, peer educators, and nurse practitioners.

Measurement: Content of transcribed focus group interviews was coded using a predetermined coding scheme based on the five dimensions of representational beliefs and emotions defined by the CSM.

Results: The providers identified that young people hold a number of STI misconceptions within each dimensions of the CSM. Anger and embarrassment about STIs are common emotions experienced by young people.

Conclusions: This investigation suggests that providers are able to elicit and identify STI‐related misconceptions held by young people, and that the CSM model is a useful classification method. Identifying misconceptions could be useful in developing tailored STI education and counseling interventions by public health nurses.
Exporting a Canadian Parenting Education Program to the Dominican Republic
Authors: McLennan John D. , Leon Tina , Haffey Sue , Barker Leslie A. S.
Published: February 2009

ABSTRACT
The framework of a Canadian‐developed parent education program, Nobody's Perfect, was used in the development of a new parent education program offered to parents attending a child nutrition rehabilitation program in the Dominican Republic. While key teaching elements of the original program were retained (e.g., encouraging active participation, emphasizing facilitation over didactic teaching, using experiential learning), locally relevant content was inserted (e.g., diarrhea prevention and treatment strategies). A Canadian team trained a group of Dominicans to deliver the new program to parents of children recovering from malnutrition. This paper describes the development, implementation, and resulting parenting program from this effort. This 8‐week program may find use in other settings. In addition, the experience gained from this exportation endeavor may be useful for others undertaking similar initiatives.
Comparing Household Listing Techniques in a Rural Midwestern Vanguard Center of the National Children's Study
Authors: Dreiling Katie , Trushenski Stacey , Kayongo‐Male Diane , Specker Bonny
Published: February 2009

ABSTRACT
The National Children's Study (NCS) is a longitudinal study that will examine the influence of environmental and social factors on the health and development of 100,000 children, following them from before birth until age 21. Proposed participant recruitment methods call for locating and listing all dwelling units (DUs) located within randomly selected segments within the 105 NCS sites. One of seven Vanguard Centers of the NCS includes four rural counties that span approximately 2,500 square miles. The size of this sampling area presents unique geographic challenges. In order to determine the most efficient method for listing DUs within this large area, a study was undertaken to investigate the differences in the percent of DUs identified and the cost of four different approaches. It compared the on‐site listing method of physically identifying each DU with three other methods: plat maps, postal listings, and Geographic Information Systems (GIS)/satellite imagery techniques. The on‐site method had the strongest κ (.85) in terms of identifying true DUs. There was a moderate agreement (.59) with the plat map method, fair agreement (.34) with the postal method, and only a slight agreement (.14) with the GIS/satellite imagery method. The plat map, postal listing, and GIS/satellite methods were less time‐consuming than the on‐site method.
Reduction of Allodynia by Intrathecal Transplantation of Microencapsulated Porcine Chromaffin Cells
Authors: Kim Yu Mi , Kwak Kyung Hwa , Lim Jeong Ok , Baek Woon Yi
Published: February 2009

Bovine chromaffin cells (BCCs) are well known to have analgesic effect to reduce acute or chronic pain when transplanted in the subarachnoid space and have been considered as an alternative therapy for pain management. However, due to recent concerns over risks associated with prion transmission, porcine tissue is considered to be an alternate xenogeneic source for clinical use. In the present study, we investigated whether microencapsulated porcine adrenal medullary chromaffin cells (PCCs) also have analgesic effect to reduce allodynia caused by neuropathic pain in chronic constriction injury model of rat. PCCs were isolated from a porcine adrenal medulla and then microencapsulated with alginate and poly. In in vitro tests, the microencapsulated PCCs were investigated whether they have an ability to release catecholamines responding to nicotine stimulation. The levels of catecholamines released from the microencapsulated PCCs were significantly higher than from microencapsulated BCCs. In addition, the microencapsulated PCCs released catecholamines and met‐enkephalin responding to cerebral spinal fluid (CSF) retrieved from a neuropathic pain model. In in vivo tests, implantation of microencapsulated PCCs reduced both mechanical and cold allodynia in chronic constriction injury model of a rat whereas the microencapsulated BCCs reduced only cold allodynia under the same conditions. The injection of antagonist of opioid peptides reversed the reduction of cold allodynia in microencapsulated PCC‐received animal. The levels of catecholamines in the CSF of rats after implantation of microencapsulated PCCs were significantly higher than in the control group. These data suggest that microencapsulated PCCs may be another effective source for the treatment of neuropathic pain.
A Passive Magnetically and Hydrodynamically Suspended Rotary Blood Pump
Authors: Stoiber Martin , Grasl Christian , Pirker Stefan , Raderer Franz , Schistek Roland , Huber Leopold , Gittler Philipp , Schima Heinrich
Published: February 2009

A combined hydrodynamic–magnetic bearing allows the design of rotary blood pumps that are not encumbered with mechanical bearings and magnets requiring sensors or electrical power. However, such pumps have so far needed very small and accurately manufactured gaps between rotor and housing to assure effective hydromagnetic bearing behavior. In order to use this concept in disposable pump heads, a design that allows larger rotor‐housing gaps, and thus larger manufacturing tolerances, is needed. A pump with passive magnetic bearings and a gap between rotor and housing in the range of 0.5 mm was designed. Numerical simulations were performed to optimize the rotor geometry at low levels of shear stress. An experimental test stand was used to find a range of speeds and gap settings that resulted in low levels of vibration and useful pressure–flow relationships. Three different rotor geometries were tested using a viscosity‐adjusted test fluid. Blood damage tests were conducted within the desirable range of speeds and gap settings. In this study stable pump performance was demonstrated at total gap widths between 0.3 and 0.7 mm at flows of 0–10 L/min, with afterloads up to 230 mm Hg. Best performance was achieved with rotors sliding on a fluid pillow between the rotor and the outer housing at a gap distance of 50 to 250 µm. The inner gap distance, between the rotor and the inner housing, could be as great as 500 µm. Hemolysis tests on the prototype within the chosen operating range showed lower values (NIH = 0.0029 ± 0.0012 g/100 L) than the Biomedicus BP‐80 pump (NIH = 0.0033 ± 0.0011 g/100 L). In conclusion, it is possible to build rotary blood pumps with passive hydromagnetic bearings that have large gaps between their rotors and housings. Rotor behavior is sensitive to the position of the permanent magnetic drive unit. To minimize vibration and blood damage, the fluid gaps and the rotational speed have to be adjusted according to the desired operating point of the pump. Further study is needed to optimize the magnetic drive unit and to ascertain its ability to withstand inertial loads imposed by sudden movements and external shock.
Assessment of a New Experimental Model of Isolated Right Ventricular Failure
Authors: Thomaz Petronio G. , Assad Renato S. , Abduch Maria C.D. , Marques Euclides , Aiello Vera D. , Stolf Noedir A.G.
Published: February 2009

We assessed a new experimental model of isolated right ventricular (RV) failure, achieved by means of intramyocardial injection of ethanol. RV dysfunction was induced in 13 mongrel dogs via multiple injections of 96% ethanol (total dose 1 mL/kg), all over the inlet and trabecular RV free walls. Hemodynamic and metabolic parameters were evaluated at baseline, after ethanol injection, and on the 14th postoperative day (POD). Echocardiographic parameters were evaluated at baseline, on the sixth POD, and on the 13th POD. The animals were then euthanized for histopathological analysis of the hearts. There was a 15.4% mortality rate. We noticed a decrease in pulmonary blood flow right after RV failure (P = 0.0018), as well as during reoperation on the 14th POD (P = 0.002). The induced RV dysfunction caused an increase in venous lactate levels immediately after ethanol injection and on the 14th POD (P < 0.0003). The echocardiogram revealed a decrease in the RV ejection fraction on the sixth and 13th PODs (P = 0.0001). There was an increased RV end‐diastolic volume on the sixth (P = 0.0001) and 13th PODs (P = 0.0084). The right ventricle showed a 74% ± 0.06% transmural infarction area, with necrotic lesions aged 14 days. Intramyocardial ethanol injection has allowed the creation of a reproducible and inexpensive model of RV failure. The hemodynamic, metabolic, and echocardiographic parameters assessed at different protocol times are compatible with severe RV failure. This model may be useful in understanding the pathophysiology of isolated right‐sided heart failure, as well as in the assessment of ventricular assist devices.
Efficacy and safety of eslicarbazepine acetate as adjunctive treatment in adults with refractory partial‐onset seizures: A randomized, double‐blind, placebo‐controlled, parallel‐group phase III study
Authors: Elger Christian , Halász Peter , Maia Joana , Almeida Luis , Soares‐da‐Silva Patrício ,   on behalf of the BIA‐2093‐301 Investigators Study Group
Published: February 2009

Purpose:  To study the efficacy and safety of eslicarbazepine acetate (ESL) as adjunctive therapy for refractory partial seizures in adults with ≥4 partial‐onset seizures (simple or complex, with or without secondary generalization) per 4 weeks despite treatment with 1–2 antiepileptic drugs (AEDs).

Methods:  This multicenter, parallel‐group study had an 8‐week, single‐blind, placebo baseline phase, after which patients were randomized to placebo (n = 102) or once‐daily ESL 400 mg (n = 100), 800 mg (n = 98), or 1,200 mg (n = 102) in the double‐blind treatment phase. ESL starting dose was 400 mg; thereafter, ESL was titrated at weekly 400‐mg steps to the full maintenance dose (12 weeks).

Results:  Seizure frequency adjusted per 4 weeks over the maintenance period (primary endpoint) was significantly lower than placebo in the ESL 1,200‐mg (p = 0.0003) and 800‐mg (p = 0.0028) groups [analysis of covariance (ANCOVA) of log‐transformed seizure frequency]. Responder rate was 20% (placebo), 23% (400 mg), 34% (800 mg), and 43% (1,200 mg). Median relative reduction in seizure frequency was 16% (placebo), 26% (400 mg), 36% (800 mg), and 45% (1,200 mg). The most frequent concomitant AEDs were carbamazepine (56–62% of patients), lamotrigine (25–27%), and valproic acid (22–28%). Similar efficacy results were obtained in patients administered ESL with or without carbamazepine as concomitant AED. Discontinuation rates caused by adverse events (AEs) were 3.9% (placebo), 4% (400 mg), 8.2% (800 mg), and 19.6% (1,200 mg). AEs in >10% of any group were dizziness, headache, and diplopia. Most AEs were mild or moderate.

Discussion:  ESL, 800 and 1,200 mg once‐daily, was well tolerated and more effective than placebo in patients who were refractory to treatment with one or two concomitant AEDs.
High frequency stimulation of the mamillothalamic tract for the treatment of resistant seizures associated with hypothalamic hamartoma
Authors: Khan Sadaquate , Wright Ingram , Javed Shazia , Sharples Peta , Jardine Philip , Carter Michael , Gill Steven S.
Published: February 2009

We investigate the clinical outcome from stimulation of the mamillothalamic tract in two patients with intractable epilepsy secondary to hypothalamic hamartomas. One patient has a left‐sided and the other a right‐sided tumor. Both patients presented with a history of gelastic and complex partial seizures resistant to multiple antiepileptic drugs. Both patients underwent insertion of a single deep brain‐stimulating electrode ipsilateral to the site of the tumor, lying adjacent to the mamillothalamic tract. Postoperatively they both had a significant reduction in seizure frequency, with one patient being seizure free for the last 10 months. An improvement in mood was reported by the patient’s primary carers and demonstrated on quality of life questionnaires.
Sleep‐Disordered Breathing in Recipients of Implantable Defibrillators
Authors: GRIMM WOLFRAM , SHARKOVA JULIA , HEITMANN JÖRG , JERRENTRUP ANDREAS , KOEHLER ULRICH , MAISCH BERNHARD
Published: February 2009

Study Objectives: To examine the prevalence and clinical significance of sleep‐disordered breathing in patients with implantable cardioverter defibrillators (ICD).

Methods and Results: Overnight sleep studies were performed in 129 ICD recipients who had no history of sleep apnea. The mean left ventricular ejection fraction (LVEF) was 29 ± 11%. Mild, moderate, and severe sleep apnea was diagnosed in the presence of an apnea/hypopnea index (AHI) of 5–15/h, 15.1–30/h, and >30/h, respectively. No sleep apnea was present in 49 patients (38%), 57 (44%) had central sleep apnea (CSA), and 23 patients (18%) had obstructive sleep apnea (OSA). Mild, moderate, and severe sleep apnea were present in 25%, 31%, and 44% of patients with CSA, compared with 52%, 22%, and 26% of patients with OSA (P < 0.05). LVEF was similar in patients with versus without OSA or CSA. Patients with CSA were significantly older and had a higher prevalence of ischemic cardiomyopathy than patients without sleep apnea.

Conclusions: Previously undiagnosed CSA is common in ICD recipients. Severely disordered breathing during sleep was more prevalent among patients with CSA than patients with OSA. This prospective, observational study will examine the long‐term clinical significance of sleep‐disordered breathing in ICD recipients.
Backup Right Ventricular Pacing with a 0.035″ Guidewire during Implantation of Left Ventricular Leads
Authors: BURRI HARAN , SUNTHORN HENRI , ZIMMERMANN MARC , STETTLER CARINE , SHAH DIPEN
Published: February 2009

Introduction: During implantation of biventricular devices, manipulation of the guiding sheath during localization of the coronary sinus (CS) ostium may result in injury to the right bundle and complete heart block. A preventive measure is to implant the right ventricular (RV) lead first, though this may interfere with manipulation of the guiding sheath and dislodge the permanent lead
. We tested the feasibility of backup pacing with a 0.035″ guidewire, advanced through the guiding sheath during CS localization.

Methods: One hundred six consecutive patients (mean age = 70 ± 11 years, 81 men) undergoing biventricular device implantation were studied. A 0.035″ guidewire with an uncoated tip was advanced into the right ventricle through the guiding sheath, and unipolar capture threshold, R‐wave sensing amplitude, and pacing impedance were measured.

Results: RV pacing was successful in all patients. The mean capture threshold was 3.8 ± 2.1 V/0.5 ms, R‐wave amplitude 5.4 ± 4.3 mV, and pacing impedance 226 ± 78 Ω. No arrhythmia was observed during the tests. Two patients developed complete heart block during the implant procedure and were successfully paced temporarily using the 0.035″ guidewire.

Conclusion: Temporary RV pacing, using a 0.035″ guidewire within the guiding sheath, is a simple, reliable, and safe method that allows backup pacing in case of traumatic complete heart block, developing during the implantation of biventricular devices.
Similar Long‐Term Benefits Conferred by Apical Versus Mid‐Septal Implantation of the Right Ventricular Lead in Recipients of Cardiac Resynchronization Therapy Systems
Authors: BULAVA ALAN , LUKL JAN
Published: February 2009

Introduction: The benefits conferred by cardiac resynchronization therapy (CRT) are markedly influenced by the left ventricular (LV) lead placement. Little is known regarding the optimal right ventricular (RV) stimulation site.

Study Objective: To compare the long‐term outcomes of CRT in patients with RV leads placed in the mid‐septal region versus the apex.

Methods and Results: This nonrandomized, observational study included 117 patients with standard indications for CRT. The LV lead was implanted on the postero‐lateral or lateral LV wall, while the RV lead was implanted at the apex (n = 82) or in the mid‐septum (n = 35). Both groups were similar with respect to baseline clinical, demographic, and echocardiographic characteristics. After 12 months of CRT, the rates of clinical response to CRT were similar in both groups (63% vs. 66%), and similar degrees of reverse LV remodeling and LV resynchronization were observed on echocardiography and color tissue Doppler imaging. A ≥30% relative increase in LV ejection fraction (EF) occurred in 76% of patients in the RV apex group, versus 49% of patients in the RV mid‐septum group (P = 0.05). A ≥45% left ventricular ejection fraction (LVEF) was measured at 12 months in 40% of patients in the RV apex group, versus 31% in the RV mid‐septum group (ns).

Conclusions: RV mid‐septal stimulation was not associated with a higher rate of response to CRT or greater improvement in LV function compared to RV apical stimulation.
Contributions of Advanced Techniques to the Success and Safety of Transvenous Leads Extraction
Authors: MARIJON ELOI , BOVEDA SERGE , DE GUILLEBON MAXIME , JACOB SOPHIE , VAHDAT OLIVIER , BARANDON LAURENT , COMBES NICOLAS , SIDOBRE LAURENT , ALBENQUE JEAN‐PAUL , CLÉMENTY JACQUES , BORDACHAR PIERRE
Published: February 2009

Purpose: We measured the proportion of intravascular leads, which can be extracted by simple traction versus with newer techniques, and examined the overall safety and success rate of lead extractions.

Methods: Between January 2005 and December 2007, 311 consecutive patients (mean age = 70 ± 14 years, 79% men) underwent extractions of 250 atrial, 318 ventricular, and 22 coronary sinus leads, in the surgical facilities of two experienced medical centers, under general anesthesia, at a mean of 7.2 ± 5.1 years (range 0.1–27.0) after lead implantation. Infection was the indication for extraction in 67.5% of cases. Complementary techniques were used when simple extraction with a locking stylet was unsuccessful.

Results: Simple traction, with or without a locking stylet, allowed the complete removal in 27.0% (95% confidence interval [CI] 22.1–31.9) of patients. A mechanical sheath, laser sheath, and/or lasso catheter were used in the remaining patients. The overall extraction success rate was 89.7% (95% CI 86.3–93.1). There was one procedure‐related death (0.3%; 95% CI 0.0–1.0). Among five other deaths occurring within 10 days after the procedure, four were due to septic shock. Duration of lead implantation was the strongest independent predictor of major adverse events (P = 0.002) and incomplete lead extraction (P = 0.005).

Conclusion: In contrast with simple traction, advanced techniques allowed the complete extraction of nearly 90% of leads. In experienced hands and with surgical back‐up, these techniques were safe. Patients presenting with infected implanted cardiac devices suffered a high rate of major adverse despite complete extraction of the lead(s).
Automated Template Matching to Pinpoint the Origin of Right Ventricular Outflow Tract Tachycardia
Authors: KUROSAKI KENJI , NOGAMI AKIHIKO , SAKAMAKI MIHIKO , KOWASE SHINYA , SUGIYASU AIKO , OGINOSAWA YASUSHI , KUBOTA SHOICHI
Published: February 2009

Background: Template matching, a technique that examines the similarity between two QRS complexes, has not been broadly applied clinically.

Methods: The 16 patients enrolled in this study underwent radiofrequency catheter ablation (RFCA) at the site of five ventricular tachycardias (VT) and of premature ventricular contractions (PVC) arising from 25 sites in the right ventricular outflow tract (RVOT), under the guidance of conventional pace and activation mapping. After RFCA, (a) a template‐matching score using a correlation coefficient, and (b) a pace‐map score were calculated at 30 successful and 48 unsuccessful ablation sites.

Results: The template‐matching score at successful ablation sites (94 ± 4%) was significantly higher than at unsuccessful (85 ± 9%) ablation sites (P < 0.001). A ≥ 90% average matching score identified successful ablation sites with a sensitivity of 90% and specificity of 69%. While there was a significant correlation between the template‐matching score and visually judged pace‐map score (r = 0.63, P < 0.0001), the area under the receiver operating characteristic curve of the template matching score was larger than that of the pace‐map score (0.80 vs. 0.67).

Conclusions: Automated template matching was useful for localizing the optimal ablation site during RFCA of RVOT‐VT/PVC.
Nontransmural Scar Detected by Magnetic Resonance Imaging and Origin of Ventricular Tachycardia in Structural Heart Disease
Authors: YOKOKAWA MIKI , TADA HIROSHI , KOYAMA KEIKO , NAITO SHIGETO , OSHIMA SHIGERU , TANIGUCHI KOICHI
Published: February 2009

Background: Contrast‐enhanced magnetic resonance imaging (CMR) identifies scar tissue as an area of delayed enhancement (DE). The scar region might be the substrate for ventricular tachycardia (VT). However, the relationship between the occurrence of VT and the characteristics of scar tissue has not been fully studied.

Methods: CMR was performed in 34 patients with monomorphic, sustained VT and dilated cardiomyopathy (DCM, n = 18), ischemic cardiomyopathy (ICM, n = 10), or idiopathic VT (IVT, n = 6). The VT exit site was assessed by a detailed analysis of the QRS morphology, including bundle branch block type, limb lead polarity, and precordial R‐wave transition. On CMR imaging, the transmural score of each of the 17 segments was assigned, using a computer‐assisted, semiautomatic technique, to measure the DE areas. Segmental scars were classified as nontransmural when DE was 1–75% and transmural when DE was 76–100% of the left ventricular mass in each segment.

Results: A scar was detected in all patients with DCM or ICM. Nontransmural scar tissue was often found at the VT exit site, in patients with DCM or ICM. In contrast, no scar was found in patients with IVT.

Conclusions: CMR clarified the characteristics and distribution of scar tissue in patients with structural heart disease, and the presence and location of scar tissue might predict the VT exit site in these patients.
Electrocardiographic Measurements of Regional Atrial Fibrillation Cycle Length
Authors: RAVI KRISHNA C. , KRUMMEN DAVID E. , TRAN AILINH J. , BULLINGA JOHN R. , NARAYAN SANJIV M.
Published: February 2009

Background: Differences in atrial fibrillation (AF) cycle length (CL) between the left (LA) and right (RA) atrium and coronary sinus (CS) may help separate paroxysmal from persistent AF and identify patients most likely to respond to pulmonary vein isolation, but has not been measured noninvasively.

Methods and Results: We developed methods to estimate regional intraatrial AF CL from the surface electrocardiogram (ECG) in 20 patients with persistent AF and 10 patients with paroxysmal AF prior to ablation. Intraatrial AF CL was measured near the LA appendage, mid‐CS, and lateral RA. In simultaneous filtered ECG, AF CL was estimated using autocorrelation. The mean of ECG‐derived AF CL in leads V5, I, and aVL was used to estimate LA CL; leads aVF, II, and III for CS CL; and V1, V2, and aVR for RA CL. ECG CL estimates for the LA, CS, and RA had R2 > 0.91 versus measured CL (all P < 0.001). Though magnitudes of left‐versus‐right AF CL gradients were small in this series, the ECG predicted the direction of gradients in 62% of measurements (P < 0.05). When the gradient was >10 ms, the direction was accurately predicted in eight of 11 patients. The accuracy of AF CL estimates was not adversely affected by AF type or LA dilatation (≤40 or >40 mm). The ECG‐estimated AF‐CL showed high 5‐minute temporal stability (P < 0.001 each chamber).

Conclusions: Left and right atrial AF CL, and their gradients, can be accurately determined from the ECG using autocorrelation analysis. This approach may be a helpful guide prior to ablation procedures.
Discrimination between His‐bundle and the Right Bundle Branch during Electrophysiologic Studies
Authors: KANEKO YOSHIAKI , NAKAJIMA TADASHI , SAITO AKIHIRO , IRIE TADANOBU , OTA MASAKI , KATO TOSHIMITSU , IIJIMA TAKAFUMI , MANITA MAMORU , ITO TOSHIO , AKIYAMA MASAHIRO , TANIGUCHI YASUHIRO , KURABAYASHI MASAHIKO
Published: February 2009

Background: The purpose of this study was to identify the His‐bundle (HB) versus right bundle branch (RBB) during electrophysiologic studies, using the V3 phenomenon, and to compare the timing of HB versus RBB potentials of sinus cycles (His‐ventricular [H‐V] interval).

Methods: The study enrolled 16 patients without structural heart disease, who underwent electrophysiologic studies during which the H‐V interval was within normal limits and the V3 phenomenon was induced during recordings of the HB and the RBB potentials by a multi‐electrode catheter. The recording site of the earliest HB potential just before the V3 phenomenon was defined as the branching portion of His bundle (HBBP), the site immediately proximal to the HBBP as the HB, and the site immediately distal to the HBBP as the RBB.

Results: The HBBP was identified in all patients. In all cases but one patient, the H‐V interval measured at the HB adjacent to the HBBP was ≥35 ms. However, in 12 patients, the H‐V interval measured at the RBB adjacent to the HBBP was also ≥35 ms.

Conclusions: The electrophysiologic identification of HB versus RBB by simultaneous recordings of HB and RBB potentials during induction of the V3 phenomenon was feasible. When the discrimination between HB and RBB was based on the measurement of the H‐V interval, the proximal portion of the RBB was frequently misidentified as the HB.
Accuracy of Swabs, Tissue Specimens, and Lead Samples in Diagnosis of Cardiac Rhythm Management Device Infections
Authors: GOLZIO PIER‐GIORGIO , VINCI MELISSA , ANSELMINO MATTEO , COMOGLIO CHIARA , RINALDI MAURO , TREVI GIAN P. , BONGIORNI MARIA GRAZIA
Published: February 2009

Aims: Pacemaker and implantable‐cardioverter defibrillator lead infections widely increased with consequent need to accurately recognize responsible bacteria.

Methods: Between May 2003 and December 2007, we extracted 118 leads, 104 (87.3%) due to infections (sepsis, lead‐associated endocarditis, pocket infection) or chronic draining sinus (with negative local bacteriological analyses). Swabs and tissue specimens from pocket and fragments of pin and tip of each extracted lead were obtained during extraction and sent for bacteriological examination.

Results: Cultures from explanted lead pins returned positive results in 100% of the cases presenting with local infections and in 92.5% of those with chronic draining sinus. In cases of sepsis, positive results of blood samples are less common than lead samples (58.3 vs 86.7, P = 0.02), the latter being more sensitive for infection diagnosis. Concordance between bacterial isolates from pocket and lead is quite low, approaching 45%, seemingly due to contamination effect. Concordance between isolates within the lead (pin and tip) is quite high, close to 70%, reflecting a more accurate expression of the real infection. In cases of sepsis, concordance between lead and blood samples, and mainly from tip and blood, is very high, resembling 80–85%; consequently bacterial isolates from the lead, particularly from lead tip, are clearly associated with clinical infections.

Conclusions: Our results strongly support the hypothesis that chronic draining sinus is often sustained by infection. Moreover, diagnostic accuracy of lead samples is higher not only than swabs and tissue samples, but also than blood samples to confirm an infection and to guide effective therapy.
Optimal Programming of the Atrioventricular Delay Using the Phonocardiogram
Authors: MIKI YUKO , ISHIKAWA TOSHIYUKI , MATSUSHITA KOHEI , YAMAKAWA YOUHEI , MATSUMOTO KATSUMI , SUMITA SHINICHI , UCHINO KAZUAKI , KIMURA KAZUO , UMEMURA SATOSHI
Published: February 2009

Purpose: To predict the optimal atrioventricular (AV) delay using the phonocardiogram (PCG).

Methods: We studied 12 recipients of cardiac resynchronization therapy (CRT) system and eight recipients of dual‐chamber pacemakers implanted for AV block with normal left ventricular (LV) function. The amplitude of the first heart sound (S1) was recorded by PCG and the LV outflow tract (OT) time‐velocity integral (TVI) was measured by pulsed Doppler echocardiography. The AV delay was prolonged in 20‐ms increments, from 60 ms to 240 ms. Ishikawa's method was used for the echocardiographic optimization of the AV delay. The relation between S1 amplitude and the AV delay was analyzed.

Results: The correlation between the amplitude of S1 and the length of AV delay showed an S‐shaped curve. The AV delay at the inflection point of each patient's S‐shaped curve (161.2 ± 19.5 ms) was positively correlated with the optimal AV delay determined by echocardiography (148.3 ± 16.9 ms, r = 0.83, P < 0.001). In addition, there was a positive correlation between the AV delay at the maximal TVI of LVOT (150.8 ± 22.7 ms) and the AV delay at the inflection point of the S‐shaped curve (159.5 ± 24.9 ms, r = 0.87, P < 0.001). In two CRT system recipients, an optimal AV delay could not be found by echocardiography; however, an optimal AV delay could be determined by PCG.

Conclusions: A high correlation was observed between the optimal AV delay determined by phonocardiography versus echocardiography.
Abnormal Atrioventricular Node Conduction and Atrioventricular Nodal Reentrant Tachycardia in Patients Older Versus Younger Than 65 Years of Age
Authors: GRECU MIHAELA , FLORIA MARIANA , GEORGESCU CATALINA ARSENESCU
Published: February 2009

Study Objective: We examined the possible role of atrioventricular node (AVN) conduction abnormalities as a cause of AVN reentrant tachycardia (RT) in patients >65 years of age.

Study Population: Slow pathway radiofrequency catheter ablation (RFCA) was performed in 104 patients. Patients in group 1 (n = 14) were >65 years of age and had AV conduction abnormalities associated with structural heart disease. Patients in group 2 (n = 90) were <65 years of age and had lone AVNRT.

Results: Patients in group 1 versus group 2 (66% vs. 46% men) had a first episode of tachycardia at an older age than in group 2 (68 ± 16.8 vs 32.5 ± 18.8 years, P = 0.007). The history of arrhythmia was shorter in group 1 (5.4 ± 3.8 vs 17.5 ± 14, P = 0.05) and was associated with a higher proportion of patients with underlying heart disease than in group 2 (79% vs 3%, P < 0.001). The electrophysiological measurements were significantly shorter in group 2: atrial‐His interval (74 ± 17 vs 144 ± 44 ms, P = 0.005), His‐ventricular (HV) interval (41 ± 5 vs 57 ± 7 ms, P = 0.001), Wenckebach cycle length (329 ± 38 vs 436 ± 90 ms, P = 0.001), slow pathway effective refractory period (268 ± 7 vs 344 ± 94 ms, P = 0.005), and tachycardia cycle length (332 ± 53 vs 426 ± 56 ms, P = 0.001). The ventriculoatrial block cycle length was similar in both groups. The immediate procedural success rate was 100% in both groups, and no complication was observed in either group. One patient in group 2 had recurrence of AVNRT. One patient with a 98‐ms HV interval underwent permanent VVI pacemaker implantation before RFCA procedure.

Conclusion: In patients undergoing RFCA for AVNRT at >65 years of age had a shorter history of tachycardia‐related symptoms than patients with lone AVNRT. The longer AVN conduction intervals and refractory period might explain the late development of AVNRT in group 1.