Search Results
Results 351 - 400 of 704
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Srivathsan Komandoor - - 2008
A 27-year-old male with congenital long QT syndrome, SCN5A mutation experienced recurrent inappropriate exercise-related implantable cardioverter defibrillator (ICD) shocks. This device showed T-wave oversensing with double, which lead to these device discharges. Dynamic T-wave oversensing was reproducibly provoked at exercise treadmill testing and was confirmed as the mechanism leading to ...
Wallbom Agnes S - - 2008
OBJECTIVES: The purpose of the study is to investigate changes in F wave parameters after exercise in subjects with symptomatic lumbar spinal stenosis. DESIGN: A total of 19 older patients with lumbar spinal stenosis and neurogenic claudication participated in this cohort study. No one withdrew for adverse effects. All subjects ...
Haapalahti Petri - - 2008
OBJECTIVES: In LQT1 subtype of inherited long QT syndrome, repolarization abnormalities originating from defective I(Ks) render patients vulnerable to ventricular arrhythmia during sudden sympathetic activation. Experimental studies show lower I(Ks) density and longer action potential duration in left (LV) than in right (RV) ventricle. We studied interventricular dispersion of repolarization ...
Sekhri Neha - - 2008
To determine whether resting and exercise electrocardiograms (ECGs) provide prognostic value that is incremental to that obtained from the clinical history in ambulatory patients with suspected angina attending chest pain clinics. Multicentre cohort study. Rapid access chest pain clinics of six hospitals in England. 8176 consecutive patients with suspected angina ...
Kounalakis Stylianos N SN Department of Sport Medicine and Biology of Exercise, Faculty of Physical Education and Sport Science, University of Athens , - - 2008
The purpose of this study was to examine the role of active muscle mass on cardiovascular drift (CVdrift) during prolonged exercise. Twelve subjects with peak oxygen uptake (VO2peak) of 3.52 ± 0.52 L·min(-1) (mean ± SD) cycled for 55 min with 80 revolutions per minute with either two legs (2-legged) ...
Bitzen Alexander - - 2007
BACKGROUND: Patients with atrial fibrillation (AF) often exhibit abnormalities of P wave morphology during sinus rhythm. We examined a novel method for automatic P wave analysis in the 24-hour-Holter-ECG of 60 patients with paroxysmal or persistent AF and 12 healthy subjects. METHODS: Recorded ECG signals were transferred to the analysis ...
Laeseke Paul F - - 2007
To compare multiple-electrode radiofrequency (RF) ablation versus RF ablation with a cluster electrode in an in vivo porcine kidney model. Thirteen female pigs (mean weight, 45 kg) were used for the study. In each animal, RF ablations were performed for 12 minutes with a conventional cluster electrode in one kidney ...
Yoshida Soichiro - - 2007
The incidence of stonestreet formation after extracorporeal shock wave lithotripsy (ESWL) rises with increasing stone burden. However, stonestreet after ESWL is often experienced even in stones smaller than 20 mm. To examine whether the non-contrast helical computed tomography (CT) data could predict stonestreet formation in these stones, 53 radiopaque stones ...
Smith Fiona E - - 2007
OBJECTIVE: Automated techniques were developed for the measurement of cardiac repolarisation using magnetocardiography. METHODS: This was achieved by collaboration with the Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany and the Grönemeyer Institute of Microtherapy, Bochum, Germany, to obtain recordings of magnetocardiograms (MCGs) in cardiac patients and healthy subjects. Manual and automated ventricular ...
Levine Saul D - - 2007
The Taser (TASER International, Scottsdale, AZ) is a high-voltage, low-amperage device used by many law enforcement agencies. Our objective in this study was to evaluate for rhythm changes utilizing cardiac monitoring during deployment of the Taser on volunteers. A prospective, observational study evaluated law enforcement personnel who had continuous electrocardiographic ...
Lampert Rachel - - 2007
INTRODUCTION: While implantable defibrillator shocks save lives, shock can lead to ventricular arrhythmias. However, the mechanism of shock-related proarrhythmia remains unclear. We evaluated the impact of ICD shock on repolarization instability, a factor associated with ventricular arrhythmogenesis. METHODS AND RESULTS: Sixty-five patients with ICDs underwent ambulatory ECG monitoring during defibrillation ...
Kligfield Paul - - 2007
BACKGROUND: The global QT interval, emerging as a standard measurement provided by digital electrocardiographs, is defined by the earliest QRS onset and latest T-wave offset that occur in any of the standard leads. Differences between global ECG measurements and those from individual ECG leads have implications for the redefinition of ...
Zhong Jing-quan - - 2007
The gap junction modifier Rotigaptide (ZP123), which promotes cellular coupling, was hypothesized to decrease defibrillation thresholds during prolonged ventricular fibrillation (VF). Thirty-two New Zealand white rabbits were randomized to receive saline (control, n = 16) or Rotigaptide (n = 16). Following 4 min of untreated VF, biphasic defibrillation shocks were ...
Inglis J Greig - - 2007
The purpose of this research was to identify the number of sessions required for a new investigator to become proficient at evoking an H-reflex in the flexor carpi radialis (FCR), in comparison to an experienced investigator. 31 students from Brock University in the greater Niagara region (16 women M age ...
Argyriou A A - - 2007
OBJECTIVE: To prospectively detect significant transient F wave abnormalities obtained after exercise in patients with peripheral arterial disease (PAD) and to assess the potential diagnostic sensitivity of dynamic F wave study in such a context. PATIENTS AND METHODS: A series of 40 electrical stimuli were delivered to the peroneal and ...
Cabasson A A Laboratory I3S-CNRS, University of Nice-Sophia Antipolis, 2000 Route des Lucioles, Sophia Antipolis cedex, France. - - 2007
The analysis of the heart period series is a difficult task especially under graded exercise conditions. Having a good tool to characterize the P-R and R-R intervals, i.e. a good method of time delay estimation, would carry out a better knowledge of the neural activity during exercise and recovery in ...
Bast Thomas - - 2006
Source localization using single current dipoles estimates equivalent centers of the spiking gray matter. The extent of the active cortex, however, is difficult to assess from scalp EEG because of the unknown individual volume conduction. The spatial scatter of dipole localizations of single spikes has been proposed as a measure ...
Lobodzinski Suave M - - 2006
We have developed a new biopotential fiber sensor (BFS) technology as an alternative to traditional wet-gel Ag/AgCl electrodes in long-term monitoring applications. Biopotential fiber sensor technology uses proprietary method of bonding copper sulfide to the surface of acrylic fibers, thus creating an electrically conductive medium (10(-1) ohms/cm). Surface modified bundles ...
Laeseke Paul F - - 2006
To prospectively evaluate, in vivo in pigs, an impedance-based multiple-electrode radiofrequency (RF) ablation system for creation of confluent areas of hepatic coagulation. The study was preapproved by the institutional research animal care and use committee. A prototype multiple-electrode RF system that enables switching between three electrically independent electrodes at impedance ...
Ariyarajah Vignendra - - 2006
Interatrial block (IAB), as denoted by P waves > or =110 ms in duration, is believed to be associated with underlying ischemia, particularly with that of its principal interatrial conduction pathway, the Bachmann bundle. In this study, the association between Duke prognostic treadmill (DPT) scores and change in P-wave duration ...
Vlachopoulos Charalambos - - 2006
OBJECTIVE: While most studies have shown an inverse relation between tea consumption and cardiovascular risk, other studies have shown opposite results. Aortic stiffness and wave reflections are markers of cardiovascular disease and prognosticators of cardiovascular risk. METHODS: The acute effect of black and green tea on aortic stiffness and wave ...
Nottin S - - 2006
Pulse wave velocity measurement is used as an index of arterial stiffness. The purpose was to evaluate the reproducibility of pulse wave velocity measurement at rest, during exercise and recovery from exercise, using an automated device. Twelve healthy young adults (mean age 22.0 +/- 3.1 yrs) underwent an upright submaximal ...
Aizawa Yoshiyasu - - 2006
Although catecholaminergic polymorphic ventricular tachycardia (CPVT) is associated with fatal ventricular arrhythmias and sudden death, the ECG findings are not fully understood. In this paper, we report on alterations in the U-wave. Seven patients from 6 families with CPVT in which bidirectional tachycardia and polymorphic VT were induced by exercise ...
Chattipakorn Nipon - - 2006
BACKGROUND: Ventricular fibrillation (VF) can be induced when a strong shock is delivered during the vulnerable period of a cardiac cycle. VF, however, cannot be induced if the shock strength is increased to the "upper limit of vulnerability" (ULV) level. Docosahexaenoic acid (DHA) has been shown to prevent the occurrence ...
Greene Barry R - - 2006
An investigation of changes in the neonatal electrocardiogram (ECG) and respiration signals from labelled seizure data for five neonatal patient records is reported. A decrease during seizure of 5.70% in the mean RR-interval was found. The mean respiration rate per epoch was found to decrease by a mean 18.44% during ...
McAllister Wallace R - - 2006
Subjects in six experimental groups (n = 16 each) received one-trial passive avoidance (PA) training in which shock was delivered upon movement from a white wooden floor compartment to a black grid compartment. Then fear was extinguished (30 min) in the black compartment. After either 24 or 168 h, all ...
Onuaguluchi Gilbert - - 2006
The electrocardiographic (ECG) profile of oral piperazine citrate was determined in healthy volunteers. Piperazine caused reduction in heart rate in all the subjects. The highest percentage of change was 15.7. The average pretreatment (73.6+/-6.59 beats/min) when compared with the heart rate 1 hour after piperazine was administered (64.6+/-5.21 beats/min) was ...
Tran Quan T QT University of Queensland , Brisbane, Queensland, - - 2006
The purpose of this study was to investigate the effects of three different weight training protocols, that varied in the way training volume was measured, on acute muscular fatigue. Ten resistance-trained males performed all three protocols which involved dynamic constant resistance exercise of the elbow flexors. Protocol A provided a ...
Tanskanen Jarno M A JM Ragnar Granit Institute, Tampere University of Technology, Tempere, Finland. - - 2006
Independent component analysis (ICA) of measured signals yields the independent sources, given certain fulfilled requirements. Properly parameterized signals provide a better view to the considered system aspects, while reducing the amount of data. It is little acknowledged that appropriately parameterized signals may be subjected to ICA, yielding independent components (ICs) ...
Vehkaoja Antti T AT Inst. of Meas. & Inf. Technol., Tampere Univ. of - - 2006
A miniature wireless node for ECG measurements is presented. The ECG node is designed to be used in various applications including measurement of heart rate during physical exercise and continuous long term measurement of ECG for people assumed having, or being recovering from a cardiac disease. The ECG node is ...
Ghanem Raja N RN Cardiac Rhythm Disease Manage., Medtronic Inc., Minneapolis, MN 55432, USA. - - 2006
Body surface Laplacian mapping localizes cardiac activity and provides more detailed distributions compared to body surface potential mapping. Systematic comparison of the performance of bipolar and Laplacian ECGs during noise has not been performed. To determine whether Laplacian ECGs (2.5 cm diameter concentric rings) can reduce noise (myopotential and motion ...
Huang Damin - - 2005
Today, radio-frequency ablation has been shown to be a safe and effective method to treat paroxysmal tachycardia with Wolff-Parkinson-White syndrome. The many criteria reported for localizing the sites of accessory pathways from a 12-lead electrocardiogram have not proven adequate to differentiate the correct sites of accessory pathways for all situations. ...
Josephsen Gary D - - 2005
This is a report of the adaptation of microwave processing in the preparation of liver biopsies for transmission electron microscopy (TEM) to examine ultrastructural damage of mitochondria in the setting of metabolic stress. Hemorrhagic shock was induced in pigs via 35% total blood volume bleed and a 90-min period of ...
Rahimi Rahman R Department of Physical Education and Sports Science, Razi University , Kermanshah, - - 2005
The purpose of this research was to compare effect 3 different rest intervals on the squat volume completed during a workout. Twenty college-aged men volunteered to participate in this study (age 20.73 ± 2.60 years; body mass 80.73 ± 10.80 kg). All subjects performed 3 testing sessions, during which 4 ...
Kay Bartholomew B Massey University , Institute of Food, Nutrition, and Human Health, Palmerston North, New - - 2005
This investigation assessed the effects of immediate or delayed re-hydration post-exercise, on mean arterial blood pressure (MAP) and on blood plasma volume (PV) expansion post-exercise. It was hypothesised that fluid ingestion would raise MAP and attenuate PV expansion. On two occasions separated by seven days, eight males (age 20.4 ± ...
Madias John E - - 2006
The aim of this study was to evaluate whether change in the patients' position during the electrocardiogram (ECG) recording alters the various components of the ECG curve. Concerns whether ECGs in medically compromised patients recorded in a sitting position should be considered "standard" tracings and whether ECGs recorded in the ...
Xia Yunlong - - 2005
The ECG interval from the peak to the end of the T wave (Tpeak-Tend) has been used as an index of transmural dispersion of ventricular repolarization (DVR). The correlation between the Tpeak-Tend interval and the global DVR, however, has not been well-evaluated. METHODS: Monophasic action potentials (MAPs) were recorded from ...
Sackner Marvin A - - 2005
STUDY OBJECTIVE: To determine if a 3-min bout of moderately intensive supine bicycle exercise, whole-body periodic acceleration (pGz), and passive motorized cycling cause nitric oxide (NO) release into the circulation, as detected by dicrotic notch descent on the diastolic limb of a finger pulse wave. PARTICIPANTS: Fourteen healthy adults underwent ...
Nirmalan Mahesh - - 2005
BACKGROUND: The transpulmonary thermal dilution technique has been widely adopted for monitoring cardiac preload and extravascular lung water in critically ill patients. This method assumes intrathoracic blood volume (ITBV) to be a fixed proportion of global end-diastolic volume (GEDV). This study determines the relation between GEDV and ITBV under normovolemic ...
Winful Herbert G - - 2005
Recent papers suggest that tunneling wave packets traverse the region of allowed propagation between two potential barriers with superluminal group velocity and in a time independent of barrier separation. This phenomenon has been termed the "generalized Hartman effect" and extended to multiple barriers. Here we show that this delay time ...
Davids Jennifer S - - 2005
OBJECTIVES: To determine whether participation in an outpatient cardiac rehabilitation (OCR) program increases exercise levels and decreases shocks in patients with implantable cardioverter-defibrillators (ICDs). DESIGN: Retrospective comparative survey. SETTING: University tertiary-care ICD clinic. PARTICIPANTS: Patients with ICDs and coronary artery disease. INTERVENTION: Participation in OCR (nonrandomized). MAIN OUTCOME MEASURES: Exercise ...
Dunbar Christopher C - - 2005
Standard electrocardiographic criteria for exercise testing require near maximal exertion and fail to detect ischemia in the presence of previous infarction or conduction or repolarization abnormalities, in women, or in the presence of certain drugs. Changes in P-wave morphology have been suggested as having diagnostic utility; however, no specific criteria ...
Tardie Gregory B GB Human Performance - - 2005
Pectus excavatum (PE) is a relatively common congenital deformity of the anterior chest wall associated with reduced exercise capacity. Uncertainty exists over the nature of physiologic impairment in PE. Evidence suggests that myocardial compression exerted by the displaced sternum on the right heart chambers, disables the ability of the heart ...
Callihan J - - 2005
BACKGROUND: Ventricular-fibrillation (VF) wave frequency is known to decrease with prolonged, untreated VF. VF wave frequency is used as an algorithm to identify VF in AEDs and ICDs; yet the nature of the frequency change is not appreciated. METHODS: In this study, anesthetized pigs were used and VF was induced ...
Kay Bartholomew B Waikato Institute of Technology, School of Sport and Exercise Science , Hamilton, New - - 2005
The effects of two volumes (1.5 L or 3.0 L) of commercially available electrolyte beverage (1.44 mM·L(-1) Na(+)) taken during a 24-hour recovery period post-exercise, on plasma volume (PV) expansion 24-hours post-exercise were assessed. A simple random-order crossover research design was used. Subjects (n = 9 males: age 21 ± ...
Berbari Edward J - - 2005
For generations of electrocardiogram (ECG) analysis, the presence of premature ventricular beats (PVBs) has been characterized as a common event in the ECG without regard to the mechanism which has caused the PVB in the first place. At best, the coupling interval with the preceding sinus beat may be noted. ...
Arya Arash - - 2005
Studies analyzing the diagnostic value of 12-lead electrocardiographic criteria differentiating slow-fast atrioventricular nodal reentrant tachycardia (AVNRT) from atrioventricular reentrant tachycardia (AVRT) due to concealed accessory pathway have shown inconsistent results. In 97 patients (50 with AVNRT, 47 with AVRT) 12-lead electrocardiograms (ECGs) were recorded during sinus rhythm and tachycardia (QRS ...
Crookes Bruce A - - 2005
BACKGROUND: Our recent experimental study showed that peripheral muscle tissue oxygen saturation (StO2), determined noninvasively by near-infrared spectroscopy (NIRS), was more reliable than systemic hemodynamics or invasive oxygenation variables as an index of traumatic shock. The purpose of this study was to establish the normal range of thenar muscle StO2 ...
Tsui Ban C H - - 2005
BACKGROUND: In the neonate, umbilical venous catheters (UVC) are inserted and advanced blindly to a predetermined length from the umbilicus. The reported rates for UVC misplacement into the liver (and occasionally the spleen) range from 20 to 37%. Radiographs are routinely used to confirm the positioning of UVCs. This involves ...
Madias John E - - 2005
Nine patients aged 76.2 +/- 8.0 years, 3 males and 6 females, who had suffered anasarca due to various illnesses, and had bundle branch block (BBB) or intraventricular conduction delays (IVCD) on admission (3 with complete left BBB [LBBB], 2 with incomplete LBBB, 2 with complete right BBB, and 2 ...
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