Minimally Invasive Epicardial Pacemaker Implantation in Neonates with Congenital Heart Block.

Science.gov (United States)

Costa, Roberto; Silva, Katia Regina da; Martinelli Filho, Martino; Carrillo, Roger

2017-10-01

Few studies have characterized the surgical outcomes following epicardial pacemaker implantation in neonates with congenital complete atrioventricular block (CCAVB). This study sought to assess the long-term outcomes of a minimally invasive epicardial approach using a subxiphoid access for pacemaker implantation in neonates. Between July 2002 and February 2015, 16 consecutive neonates underwent epicardial pacemaker implantation due to CCAVB. Among these, 12 (75.0%) had congenital heart defects associated with CCAVB. The patients had a mean age of 4.7 ± 5.3 days and nine (56.3%) were female. Bipolar steroid-eluting epicardial leads were implanted in all patients through a minimally invasive subxiphoid approach and fixed on the diaphragmatic ventricular surface. The pulse generator was placed in an epigastric submuscular position. All procedures were successful, with no perioperative complications or early deaths. Mean operating time was 90.2 ± 16.8 minutes. None of the patients displayed pacing or sensing dysfunction, and all parameters remained stable throughout the follow-up period of 4.1 ± 3.9 years. Three children underwent pulse generator replacement due to normal battery depletion at 4.0, 7.2, and 9.0 years of age without the need of ventricular lead replacement. There were two deaths at 12 and 325 days after pacemaker implantation due to bleeding from thrombolytic use and progressive refractory heart failure, respectively. Epicardial pacemaker implantation through a subxiphoid approach in neonates with CCAVB is technically feasible and associated with excellent surgical outcomes and pacing lead longevity.

Correlates of current suicide risk among Thai patients with bipolar I disorder: findings from the Thai Bipolar Disorder Registry

Directory of Open Access Journals (Sweden)

Suttajit S

2013-11-01

Full Text Available Sirijit Suttajit,1 Suchat Paholpak,2 Somrak Choovanicvong,3 Khanogwan Kittiwattanagul,4 Wetid Pratoomsri,5 Manit Srisurapanont1On behalf of the Thai Bipolar Registry Group1Department of Psychiatry, Chiang Mai University, Chiang Mai, 2Department of Psychiatry, Khon Kaen University, Khon Kaen, 3Srithanya Hospital, Nonthaburi, 4Khon Kaen Rajanagarindra Psychiatric Hospital, Khon Kaen, 5Chachoengsao Hospital, Chachoengsao, ThailandBackground: The Thai Bipolar Disorder Registry was a prospective, multisite, naturalistic study conducted in 24 hospitals across Thailand. This study aimed to examine the correlates of current suicide risk in Thai patients with bipolar I disorder.Methods: Participants were adult inpatients or outpatients with bipolar disorder, based on the Diagnosis and Statistical Manual of Mental Disorders, fourth edition. All were assessed by using the Mini International Neuropsychiatric Interview (MINI, version 5. The severity of current suicide risk was determined by using the total score of the MINI suicidality module. Mood symptoms were assessed by using the Young Mania Rating Scale and the Montgomery Asberg Depression Rating Scale.Results: The data of 383 bipolar I disorder patients were included in the analyses. Of these, 363 (94.8% were outpatients. The mean (standard deviation of the MINI suicide risk score was 1.88 (5.0. The demographic/clinical variables significantly associated with the MINI suicide risk scores included age, number of overall previous episodes, the Young Mania Rating Scale score, the Montgomery Asberg Depression Rating Scale scores, and the Clinical Global Impression Severity of Illness Scale for Bipolar Disorder mania score, depression score, and overall score. The variables affecting the differences of suicide risk scores between or among groups were type of first mood episode, a history of rapid cycling, anxiety disorders, and alcohol use disorders. The stepwise multiple linear regression model revealed

Leadless Pacemakers: State of the Art and Future Perspectives.

Science.gov (United States)

Della Rocca, Domenico G; Gianni, Carola; Di Biase, Luigi; Natale, Andrea; Al-Ahmad, Amin

2018-03-01

Leadless pacemaker therapy is a new technology that aims at avoiding lead- and pocket-related complications of conventional transvenous and epicardial pacing. To date, 2 self-contained leadless pacemakers for right ventricular pacing have been clinically available: the Nanostim Leadless Pacemaker System and the Micra Transcatheter Pacing System. Additionally, a new multicomponent leadless pacemaker for endocardial left ventricular pacing has been proposed as an alternative choice for cardiac resynchronization therapy. In this review, we describe the state of the art of leadless pacing and compare the currently available devices with traditional transvenous leadless pacemakers. Copyright © 2017 Elsevier Inc. All rights reserved.

Cardiac Pacemakers

International Nuclear Information System (INIS)

Fiandra, O.; Espasandin, W.; Fiandra, H.

1984-01-01

A complete survey of physiological biophysical,clinical and engineering aspects of cardiac facing,including the history and an assessment of possible future developments.Among the topics studied are: pacemakers, energy search, heart stimulating with pacemakers ,mathematical aspects of the electric cardio stimulation chronic, pacemaker implants,proceeding,treatment and control

The effect of therapeutic x-radiation on a sample of pacemaker generators

International Nuclear Information System (INIS)

Maxted, K.J.

1984-01-01

Tests were made on nineteen generators, comprising seventeen types from five manufacturers and including four programmable units, and x-ray energies of about 4 MeV. The bipolar generators suffered no measureable damage and radiotherapy patients using these would appear not to be exposed to any hazard. Nor were any of the generators using entirely CMOS circuitry, including the programmable types, affected. Generators using hybrid bipolar and CMOS circuitry were damaged by radiation exposure, the majority of these being Medtronic pacemakers. Transient recovery of function followed by total failure suggested that even a transient loss of function must be regarded as a precursor to permanent damage. This transient effect indicates that it is most likely the CMOS circuit element that is affected. (U.K.)

Firing Patterns and Transitions in Coupled Neurons Controlled by a Pacemaker

International Nuclear Information System (INIS)

Mei-Sheng, Li; Qi-Shao, Lu; Li-Xia, Duan; Qing-Yun, Wang

2008-01-01

To reveal the dynamics of neuronal networks with pacemakers, the firing patterns and their transitions are investigated in a ring HR neuronal network with gap junctions under the control of a pacemaker. Compared with the situation without pacemaker, the neurons in the network can exhibit various firing patterns as the external current is applied or the coupling strength of pacemaker varies. The results are beneficial for understanding the complex cooperative behaviour of large neural assemblies with pacemaker control

A current-controlled PWM bipolar power supply for a magnet load

International Nuclear Information System (INIS)

Kang, Y.G.; McGhee, D.G.

1994-01-01

The Advanced Photon Source, at Argonne National Laboratory will produce the world's brightest x-ray beams when it is complete. A number of correction magnets are used to maintain proper beam position. Basically, two different types of bipolar power supplies are used for all the correction magnets: one requires dc correction only, and the other requires dc and ac correction. Normally linear-mode power amplifiers would be used for the bipolar power supplies. However, linear-mode power amplifiers dissipate a substantial amount of power as heat, resulting in poor efficiency for their large size. In addition, most commercial bipolar power supplies are linear-mode and available for lower power levels. Therefore, for higher power levels it was necessary to design a bipolar power supply that uses switch-mode power conversion. This paper describes a control technique for a pulse-width-modulatcd bipolar power supply, which can deliver a controlled current, dc plus ac to a correction magnet. A design example of a 150A bipolar power supply is presented

The pacemaker-twiddler's syndrome: an infrequent cause of pacemaker failure.

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Salahuddin, Mohammad; Cader, Fathima Aaysha; Nasrin, Sahela; Chowdhury, Mashhud Zia

2016-01-20

The pacemaker-twiddler's syndrome is an uncommon cause of pacemaker malfunction. It occurs due to unintentional or deliberate manipulation of the pacemaker pulse generator within its skin pocket by the patient. This causes coiling of the lead and its dislodgement, resulting in failure of ventricular pacing. More commonly reported among elderly females with impaired cognition, the phenomenon usually occurs in the first year following pacemaker implantation. Treatment involves repositioning of the dislodged leads and suture fixation of the lead and pulse generator within its pocket. An 87 year old Bangladeshi lady who underwent a single chamber ventricular pacemaker (VVI mode: i.e. ventricle paced, ventricle sensed, inhibitory mode) implantation with the indication of complete heart block, and presented to us again 7 weeks later, with syncopal attacks. She admitted to repeatedly manipulating the pacemaker generator in her left pectoral region. Physical examination revealed a heart rate of 42 beats/minute, blood pressure 140/80 mmHg and bilateral crackles on lung auscultation. She had no cognitive deficit. An immediate electrocardiogram showed complete heart block with pacemaker spikes and failure to capture. Chest X-ray showed coiled and retracted right ventricular lead and rotated pulse generator. An emergent temporary pace maker was set at a rate of 60 beats per minute. Subsequently, she underwent successful lead repositioning with strong counselling to avoid further twiddling. Twiddler's syndrome should be considered as a cause of pacemaker failure in elderly patients presenting with bradyarrythmias following pacemaker implantation. Chest X-ray and electrocardiograms are simple and easily-available first line investigations for its diagnosis. Lead repositioning is required, however proper patient education and counselling against further manipulation is paramount to long-term management.

Advanced Pacemaker

Science.gov (United States)

1990-01-01

Synchrony, developed by St. Jude Medical's Cardiac Rhythm Management Division (formerly known as Pacesetter Systems, Inc.) is an advanced state-of-the-art implantable pacemaker that closely matches the natural rhythm of the heart. The companion element of the Synchrony Pacemaker System is the Programmer Analyzer APS-II which allows a doctor to reprogram and fine tune the pacemaker to each user's special requirements without surgery. The two-way communications capability that allows the physician to instruct and query the pacemaker is accomplished by bidirectional telemetry. APS-II features 28 pacing functions and thousands of programming combinations to accommodate diverse lifestyles. Microprocessor unit also records and stores pertinent patient data up to a year.

Intracellular Ca(2+) release from endoplasmic reticulum regulates slow wave currents and pacemaker activity of interstitial cells of Cajal.

Science.gov (United States)

Zhu, Mei Hong; Sung, Tae Sik; O'Driscoll, Kate; Koh, Sang Don; Sanders, Kenton M

2015-04-15

Interstitial cells of Cajal (ICC) provide pacemaker activity in gastrointestinal muscles that underlies segmental and peristaltic contractions. ICC generate electrical slow waves that are due to large-amplitude inward currents resulting from anoctamin 1 (ANO1) channels, which are Ca(2+)-activated Cl(-) channels. We investigated the hypothesis that the Ca(2+) responsible for the stochastic activation of ANO1 channels during spontaneous transient inward currents (STICs) and synchronized activation of ANO1 channels during slow wave currents comes from intracellular Ca(2+) stores. ICC, obtained from the small intestine of Kit(+/copGFP) mice, were studied under voltage and current clamp to determine the effects of blocking Ca(2+) uptake into stores and release of Ca(2+) via inositol 1,4,5-trisphosphate (IP3)-dependent and ryanodine-sensitive channels. Cyclocpiazonic acid, thapsigargin, 2-APB, and xestospongin C inhibited STICs and slow wave currents. Ryanodine and tetracaine also inhibited STICs and slow wave currents. Store-active compounds had no direct effects on ANO1 channels expressed in human embryonic kidney-293 cells. Under current clamp, store-active drugs caused significant depolarization of ICC and reduced spontaneous transient depolarizations (STDs). After block of ryanodine receptors with ryanodine and tetracaine, repolarization did not restore STDs. ANO1 expressed in ICC has limited access to cytoplasmic Ca(2+) concentration, suggesting that pacemaker activity depends on Ca(2+) dynamics in restricted microdomains. Our data from studies of isolated ICC differ somewhat from studies on intact muscles and suggest that release of Ca(2+) from both IP3 and ryanodine receptors is important in generating pacemaker activity in ICC. Copyright © 2015 the American Physiological Society.

Intracellular Ca2+ release from endoplasmic reticulum regulates slow wave currents and pacemaker activity of interstitial cells of Cajal

Science.gov (United States)

Zhu, Mei Hong; Sung, Tae Sik; O'Driscoll, Kate; Koh, Sang Don

2015-01-01

Interstitial cells of Cajal (ICC) provide pacemaker activity in gastrointestinal muscles that underlies segmental and peristaltic contractions. ICC generate electrical slow waves that are due to large-amplitude inward currents resulting from anoctamin 1 (ANO1) channels, which are Ca2+-activated Cl− channels. We investigated the hypothesis that the Ca2+ responsible for the stochastic activation of ANO1 channels during spontaneous transient inward currents (STICs) and synchronized activation of ANO1 channels during slow wave currents comes from intracellular Ca2+ stores. ICC, obtained from the small intestine of Kit+/copGFP mice, were studied under voltage and current clamp to determine the effects of blocking Ca2+ uptake into stores and release of Ca2+ via inositol 1,4,5-trisphosphate (IP3)-dependent and ryanodine-sensitive channels. Cyclocpiazonic acid, thapsigargin, 2-APB, and xestospongin C inhibited STICs and slow wave currents. Ryanodine and tetracaine also inhibited STICs and slow wave currents. Store-active compounds had no direct effects on ANO1 channels expressed in human embryonic kidney-293 cells. Under current clamp, store-active drugs caused significant depolarization of ICC and reduced spontaneous transient depolarizations (STDs). After block of ryanodine receptors with ryanodine and tetracaine, repolarization did not restore STDs. ANO1 expressed in ICC has limited access to cytoplasmic Ca2+ concentration, suggesting that pacemaker activity depends on Ca2+ dynamics in restricted microdomains. Our data from studies of isolated ICC differ somewhat from studies on intact muscles and suggest that release of Ca2+ from both IP3 and ryanodine receptors is important in generating pacemaker activity in ICC. PMID:25631870

Protection of pacemaker wearers: effects on magnetic fields on the operation of implanted cardiac pacemakers

International Nuclear Information System (INIS)

Souques, M.; Lambrozo, J.; Frank, R.; Himbert, C.

2002-01-01

The aim of this study was to assess the changes in the behavior of cardiac pacemakers exposed to 50 and 60 Hz magnetic fields generated by industrial current and 20 to 50 khz magnetic fields generated by a household in a booming period - the induction cook top - and to study the incidence of these changes in a population of subjects with implanted pacemakers. This will enabled to give patients advices about dealing with electric transport lines and facilities and with induction cook tops and to advise manufacturers about the risks involved

Small functional If current in sinoatrial pacemaker cells of the brown trout (Salmo trutta fario) heart despite strong expression of HCN channel transcripts.

Science.gov (United States)

Hassinen, Minna; Haverinen, Jaakko; Vornanen, Matti

2017-12-01

Funny current ( I f ), formed by hyperpolarization-activated cyclic nucleotide-gated channels (HCN channels), is supposed to be crucial for the membrane clock regulating the cardiac pacemaker mechanism. We examined the presence and activity of HCN channels in the brown trout ( Salmo trutta fario ) sinoatrial (SA) pacemaker cells and their putative role in heart rate ( f H ) regulation. Six HCN transcripts (HCN1, HCN2a, HCN2ba, HCN2bb, HCN3, and HCN4) were expressed in the brown trout heart. The total HCN transcript abundance was 4.0 and 4.9 times higher in SA pacemaker tissue than in atrium and ventricle, respectively. In the SA pacemaker, HCN3 and HCN4 were the main isoforms representing 35.8 ± 2.7 and 25.0 ± 1.5%, respectively, of the total HCN transcripts. Only a small I f with a mean current density of -1.2 ± 0.37 pA/pF at -140 mV was found in 4 pacemaker cells out of 16 spontaneously beating cells examined, despite the optimization of recording conditions for I f activity. I f was not found in any of the 24 atrial myocytes and 21 ventricular myocytes examined. HCN4 coexpressed with the MinK-related peptide 1 (MiRP1) β-subunit in CHO cells generated large I f currents. In contrast, HCN3 (+MiRP1) failed to produce I f in the same expression system. Cs + (2 mM), which blocked 84 ± 12% of the native I f , reversibly reduced f H 19.2 ± 3.6% of the excised multicellular pacemaker tissue from 53 ± 5 to 44 ± 5 beats/min ( P brown trout heart is largely independent on I f . Copyright © 2017 the American Physiological Society.

Pacemaker (image)

Science.gov (United States)

A pacemaker is a small, battery-operated electronic device which is inserted under the skin to help the heart beat regularly and at an appropriate rate. The pacemaker has leads that travel through a large vein ...

Evidences of the ultrarapid delayed rectifier potassium current (IKur on pacemaker activity in sinoatrial and atrioventricular nodes of Rat

Directory of Open Access Journals (Sweden)

Mohammad reza Nikmaram

2008-09-01

Full Text Available Background: Sinoatrial node (SAN is the primary pacemaker of the heart. If the SAN activity fails in any way, then the atrioventricular node (AVN immediately starts to regulate the activities of the heart. The aim of this study was to assess the existence or non existence of ultrarapid delayed rectifier potassium current (Ikur and its role on pacemaker activity of two intact SAN and AVN of rat. Methods: The pacemaker activities of distinct intact SAN and AVN by two separate metal microelectrodes that contact the endothelial surface of nodes were recorded and cycle length (CL of action potential was measured. The recording was done before and during 50µM 4-Aminopyridine (4-AP as an Ikur blocker. Results: Compared to control condition, CL of action potentials of SAN and VAN preparations had increased by 17.60 +/-2.9% and 35.90 +/-2.9%, respectively (P<0.05. Conclusion: It is possible to conclude that the Ikur was present in AVN and SAN and the effect of 4-AP on CL of action potential nodes was significantly different.

Influencing programmable pacemakers by radiation therapy

International Nuclear Information System (INIS)

Wilm, M.; Kronholz, H.L.; Schuetz, J.; Koch, T.

1994-01-01

More than 300,000 pacemakers are implanted worldwide. During radiation therapy a damage of the pacemaker elektronic is possible. Twenty pacemakers have been irradiated with photons or electrons experimentally in three different situations: a) pacemaker and pacemaker electrode outside of the irradiation field; b) pacemaker outside, pacemaker electrode inside the irradiation field; c) all things inside the irradiation field. The voltage in the pacemaker electrode produced by the electric field of the accelerator did not exceed 0.8 mV if the electrode was outside the irradiation field. Induced voltage was up to 1.2 mV during irradiation with electrons (18 MeV) and the electrode being inside the treatment field with more than two thirds of its length. After delivering of not more than 10 Gy (photons) to the pacemaker, a decreasing amplitude of the pacemaker pulse occurred. The pulse frequency did not show any deviation. This seems to signal a severe early irreversible damage of the pacemaker that may cause sudden breakdown days or weeks after radiation. Two pacemakers showed a complete breakdown after irradiation with not more than 10 Gy. The others had a complete breakdown beyond doses of 50 Gy. (orig./MG) [de

Effects of irradiation on the components of implantable pacemakers

CERN Document Server

Kawamura, S; Kuga, N; Shiba, T; Hirose, T; Fujimoto, H; Toyoshima, T; Hyodo, K; Matoba, M

2003-01-01

The purpose of this study was to examine the effects of irradiation on implantable pacemaker components. The pacemaker was divided into three components: lead wire and electrode, battery, and electrical circuit, and each component was irradiated by X-ray and electron beams, respectively. The pacemaker parameters were measured by both telemetry data of the programmer and directly measured data from the output terminal. The following results were obtained. For the lead wire and electrode, there was no effect on the pacemaker function due to irradiation by X-ray and electron beams. In the case of battery irradiation, there was no change in battery voltage or current up to 236 Gy X-ray dose. In the electrical circuit, the pacemaker reverted to the regular beating rate (fixed-rate mode) immediately after the start of X-ray irradiation, and it continued in this mode during irradiation. In patients with their own heartbeat rhythm, changing to the fixed-rate mode may cause dangerous conditions such as ventricular fib...

Bipolar Treatment: Are Bipolar I and Bipolar II Treated Differently?

Science.gov (United States)

... The diagnosis and management of bipolar I and bipolar II disorders: Clinical practice update. Mayo Clinic Proceedings. 2017;92:1532. Haynes PL, et al. Social rhythm therapies for mood disorders: An update. Current Psychiatry Reports. ...

Cardiac Pacemakers; Marcapasos Cardiacos

Energy Technology Data Exchange (ETDEWEB)

Fiandra, O [Universidad de la Republica, Facultad de Maedicina, Departamento de Cardiologia, Montevideo(Uruguay); Espasandin, W [Universidad de la Republica, Facultad de Medicina, Departamento de Cirugia Cardiaca, Montevideo (Uruguay); Fiandra, H [Instituto Nacional de Cirugia Cardiaca, Departamento de Hemodinamia y Marcapasos, Montevideo (Uruguay); and others

1984-07-01

A complete survey of physiological biophysical,clinical and engineering aspects of cardiac facing,including the history and an assessment of possible future developments.Among the topics studied are: pacemakers, energy search, heart stimulating with pacemakers ,mathematical aspects of the electric cardio stimulation chronic, pacemaker implants,proceeding,treatment and control.

Cognitive and family correlates of current suicidal ideation in children with bipolar disorder.

Science.gov (United States)

Weinstein, Sally M; Van Meter, Anna; Katz, Andrea C; Peters, Amy T; West, Amy E

2015-03-01

Suicidality among youth with bipolar disorder is an extreme, but largely unaddressed, public health problem. The current study examined the psychosocial characteristics differentiating youth with varying severities of suicidal ideation that may dictate targets for suicide prevention interventions. Participants included 72 youth aged 7-13 (M=9.19, SD=1.61) with DSM-IV-TR bipolar I, II, or NOS and a parent/caregiver. Current suicidal ideation and correlates were assessed at intake, including: demographics and clinical factors (diagnosis, symptom severity, psychiatric comorbidity); child factors (cognitive risk and quality of life); and family factors (parenting stress, family cohesion, and family rigidity). Current ideation was prevalent in this young sample: 41% endorsed any ideation, and 31% endorsed active forms. Depression symptoms, quality of life, hopelessness, self-esteem, and family rigidity differentiated youth with increasing ideation severity. Separate logistic regressions examined all significant child- and family-level factors, controlling for demographic and clinical variables. Greater family rigidity and lower self-esteem remained significant predictors of current planful ideation. Diagnosis, index episode, comorbidity, and mania severity did not differentiate non-ideators from those with current ideation. Limitations include the small sample to examine low base-rate severe ideation, cross-sectional analyses and generalizability of findings beyond the outpatient clinical sample. Findings underscore the importance of assessing and addressing suicidality in preadolescent youth with bipolar disorder, before youth progress to more severe suicidal behaviors. Results also highlight child self-esteem and family rigidity as key treatment targets to reduce suicide risk in pediatric bipolar disorder. Copyright © 2014 Elsevier B.V. All rights reserved.

Toward a complex system understanding of bipolar disorder: A chaotic model of abnormal circadian activity rhythms in euthymic bipolar disorder.

Science.gov (United States)

Hadaeghi, Fatemeh; Hashemi Golpayegani, Mohammad Reza; Jafari, Sajad; Murray, Greg

2016-08-01

In the absence of a comprehensive neural model to explain the underlying mechanisms of disturbed circadian function in bipolar disorder, mathematical modeling is a helpful tool. Here, circadian activity as a response to exogenous daily cycles is proposed to be the product of interactions between neuronal networks in cortical (cognitive processing) and subcortical (pacemaker) areas of the brain. To investigate the dynamical aspects of the link between disturbed circadian activity rhythms and abnormalities of neurotransmitter functioning in frontal areas of the brain, we developed a novel mathematical model of a chaotic system which represents fluctuations in circadian activity in bipolar disorder as changes in the model's parameters. A novel map-based chaotic system was developed to capture disturbances in circadian activity across the two extreme mood states of bipolar disorder. The model uses chaos theory to characterize interplay between neurotransmitter functions and rhythm generation; it aims to illuminate key activity phenomenology in bipolar disorder, including prolonged sleep intervals, decreased total activity and attenuated amplitude of the diurnal activity rhythm. To test our new cortical-circadian mathematical model of bipolar disorder, we utilized previously collected locomotor activity data recorded from normal subjects and bipolar patients by wrist-worn actigraphs. All control parameters in the proposed model have an important role in replicating the different aspects of circadian activity rhythm generation in the brain. The model can successfully replicate deviations in sleep/wake time intervals corresponding to manic and depressive episodes of bipolar disorder, in which one of the excitatory or inhibitory pathways is abnormally dominant. Although neuroimaging research has strongly implicated a reciprocal interaction between cortical and subcortical regions as pathogenic in bipolar disorder, this is the first model to mathematically represent this

Programmable Pacemaker

Science.gov (United States)

1996-01-01

Released in 1995, the Trilogy cardiac pacemaker is the fourth generation of a unit developed in the 1970s by NASA, Johns Hopkins Applied Physics Laboratory and St. Jude Medical's Cardiac Rhythm Management Division (formerly known as Pacesetter Systems, Inc.). The new system incorporates the company's PDx diagnostic and programming software and a powerful microprocessor that allows more functions to be fully automatic and gives more detailed information on the patient's health and the performance of the pacing systems. The pacemaker incorporates bidirectional telemetry used for space communications for noninvasive communication with the implanted pacemaker, smaller implantable pulse generators from space microminiaturization, and longer-life batteries from technology for spacecraft electrical power systems.

Electrophysiological heterogeneity of pacemaker cells in the rabbit intercaval region, including the SA node: insights from recording multiple ion currents in each cell.

Science.gov (United States)

Monfredi, Oliver; Tsutsui, Kenta; Ziman, Bruce; Stern, Michael D; Lakatta, Edward G; Maltsev, Victor A

2018-03-01

Cardiac pacemaker cells, including cells of the sinoatrial node, are heterogeneous in size, morphology, and electrophysiological characteristics. The exact extent to which these cells differ electrophysiologically is unclear yet is critical to understanding their functioning. We examined major ionic currents in individual intercaval pacemaker cells (IPCs) sampled from the paracristal, intercaval region (including the sinoatrial node) that were spontaneously beating after enzymatic isolation from rabbit hearts. The beating rate was measured at baseline and after inhibition of the Ca 2+ pump with cyclopiazonic acid. Thereafter, in each cell, we consecutively measured the density of funny current ( I f ), delayed rectifier K + current ( I K ) (a surrogate of repolarization capacity), and L-type Ca 2+ current ( I Ca,L ) using whole cell patch clamp . The ionic current densities varied to a greater extent than previously appreciated, with some IPCs demonstrating very small or zero I f . The density of none of the currents was correlated with cell size, while I Ca,L and I f densities were related to baseline beating rates. I f density was correlated with I K density but not with that of I Ca,L . Inhibition of Ca 2+ cycling had a greater beating rate slowing effect in IPCs with lower I f densities. Our numerical model simulation indicated that 1) IPCs with small (or zero) I f or small I Ca,L can operate via a major contribution of Ca 2+ clock, 2) I f -Ca 2+ -clock interplay could be important for robust pacemaking function, and 3) coupled I f - I K function could regulate maximum diastolic potential. Thus, we have demonstrated marked electrophysiological heterogeneity of IPCs. This heterogeneity is manifested in basal beating rate and response to interference of Ca 2+ cycling, which is linked to I f . NEW & NOTEWORTHY In the present study, a hitherto unrecognized range of heterogeneity of ion currents in pacemaker cells from the intercaval region is demonstrated

Pacemaker Use Following Heart Transplantation

Science.gov (United States)

Mallidi, Hari R.; Bates, Michael

2017-01-01

Background: The incidence of permanent pacemaker implantation after orthotopic heart transplantation has been reported to be 2%-24%. Transplanted hearts usually exhibit sinus rhythm in the operating room following reperfusion, and most patients do not exhibit significant arrhythmias during the postoperative period. However, among the patients who do exhibit abnormalities, pacemakers may be implanted for early sinus node dysfunction but are rarely used after 6 months. Permanent pacing is often required for atrioventricular block. A different cohort of transplant patients presents later with bradycardia requiring pacemaker implantation, reported to occur in approximately 1.5% of patients. The objectives of this study were to investigate the indications for pacemaker implantation, compare the need for pacemakers following bicaval vs biatrial anastomosis, and examine the long-term outcomes of heart transplant patients who received pacemakers. Methods: For this retrospective, case-cohort, single-institution study, patients were identified from clinical research and administrative transplant databases. Information was supplemented with review of the medical records. Standard statistical techniques were used, with chi-square testing for categorical variables and the 2-tailed t test for continuous variables. Survival was compared with the use of log-rank methods. Results: Between January 1968 and February 2008, 1,450 heart transplants were performed at Stanford University. Eighty-four patients (5.8%) were identified as having had a pacemaker implanted. Of these patients, 65.5% (55) had the device implanted within 30 days of transplantation, and 34.5% (29) had late implantation. The mean survival of patients who had an early pacemaker implant was 6.4 years compared to 7.7 years for those with a late pacemaker implant (Ppacemaker implantation. Starting in 1997, a bicaval technique was used for implantation. The incidence of pacemaker implantation by technique was 2.0% for

Current use of implantable electrical devices in Sweden: data from the Swedish pacemaker and implantable cardioverter-defibrillator registry.

Science.gov (United States)

Gadler, Fredrik; Valzania, Cinzia; Linde, Cecilia

2015-01-01

The National Swedish Pacemaker and Implantable Cardioverter-Defibrillator (ICD) Registry collects prospective data on all pacemaker and ICD implants in Sweden. We aimed to report the 2012 findings of the Registry concerning electrical devices implantation rates and changes over time, 1 year complications, long-term device longevity and patient survival. Forty-four Swedish implanting centres continuously contribute implantation of pacemakers and ICDs to the Registry by direct data entry on a specific website. Clinical and technical information on 2012 first implants and postoperative complications were analysed and compared with previous years. Patient survival data were obtained from the Swedish population register database. In 2012, the mean pacemaker and ICD first implantation rates were 697 and 136 per million inhabitants, respectively. The number of cardiac resynchronization therapy (CRT) first implantations/million capita was 41 (CRT pacemakers) and 55 (CRT defibrillators), with only a slight increase in CRT-ICD rate compared with 2011. Most device implantations were performed in men. Complication rates for pacemaker and ICD procedures were 5.3 and 10.1% at 1 year, respectively. Device and lead longevity differed among manufacturers. Pacemaker patients were older at the time of first implant and had generally worse survival rate than ICD patients (63 vs. 82% after 5 years). Pacemaker and ICD implantation rates seem to have reached a level phase in Sweden. Implantable cardioverter-defibrillator and CRT implantation rates are very low and do not reflect guideline indications. Gender differences in CRT and ICD implantations are pronounced. Device and patient survival rates are variable, and should be considered when deciding device type. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

[Analysis of pacemaker ECGs].

Science.gov (United States)

Israel, Carsten W; Ekosso-Ejangue, Lucy; Sheta, Mohamed-Karim

2015-09-01

The key to a successful analysis of a pacemaker electrocardiogram (ECG) is the application of the systematic approach used for any other ECG without a pacemaker: analysis of (1) basic rhythm and rate, (2) QRS axis, (3) PQ, QRS and QT intervals, (4) morphology of P waves, QRS, ST segments and T(U) waves and (5) the presence of arrhythmias. If only the most obvious abnormality of a pacemaker ECG is considered, wrong conclusions can easily be drawn. If a systematic approach is skipped it may be overlooked that e.g. atrial pacing is ineffective, the left ventricle is paced instead of the right ventricle, pacing competes with intrinsic conduction or that the atrioventricular (AV) conduction time is programmed too long. Apart from this analysis, a pacemaker ECG which is not clear should be checked for the presence of arrhythmias (e.g. atrial fibrillation, atrial flutter, junctional escape rhythm and endless loop tachycardia), pacemaker malfunction (e.g. atrial or ventricular undersensing or oversensing, atrial or ventricular loss of capture) and activity of specific pacing algorithms, such as automatic mode switching, rate adaptation, AV delay modifying algorithms, reaction to premature ventricular contractions (PVC), safety window pacing, hysteresis and noise mode. A systematic analysis of the pacemaker ECG almost always allows a probable diagnosis of arrhythmias and malfunctions to be made, which can be confirmed by pacemaker control and can often be corrected at the touch of the right button to the patient's benefit.

Pacemaker diagnostics in atrial fibrillation: limited usefulness for therapy initiation in a pacemaker practice.

Science.gov (United States)

Yedlapati, Neeraja; Fisher, John D

2014-09-01

We aimed to determine the practical value of pacemaker diagnostics for atrial fibrillation (AF) in an unselected general pacemaker practice, specifically workflow and initiation of anticoagulation or antiarrhythmic drug (AAD) therapy. We prospectively followed consecutive pacemaker interrogations over a period of 1 year to identify patients with AF (burden from 1% to 99%). We contacted referring physicians with AF details, and then determined whether the information resulted in therapeutic changes. Of the 1,100 pacemakers interrogated, 728 were dual chamber (DDDs) with AF diagnostic capability. AF was recorded in 73 (10%) but seven had limited information, leaving 66 patients; of these, 42 (63%) patients were already anticoagulated and in five (7%) patients, anticoagulation had been stopped because of complications. Initial diagnosis of AF was made by the pacemaker in 17 patients (26% of 66; 2% of 728); four (6% of 66) patients were newly initiated on anticoagulation. Of the 66 patients, 17 patients were already on AADs; 49 (74%) had satisfactory rate control or had other issues; only two (3% of 66; 0.3% of 728) received new AADs. Of 728 patients with DDD pacemakers, only 17 were newly discovered to have AF, and six (0.8%) had changes in medications based on the pacemaker data. Adding pacemaker-derived data to existing clinical information had little therapeutic impact, due to a combination of cumbersome workflow, and because AF was usually known to practitioners. Developments in automated monitoring systems may provide more accessible and therapeutically useful information. ©2014 Wiley Periodicals, Inc.

Psychosocial responses of children to cardiac pacemakers.

Science.gov (United States)

Alpern, D; Uzark, K; Dick, M

1989-03-01

To examine the psychosocial responses of children and adolescents with a cardiac pacemaker and compare their responses to those of their peers, we evaluated 30 pediatric pacemaker patients, aged 7 to 19 years, and two age- and sex-matched comparison groups, including 30 patients with similar heart disease but without pacemakers and 30 physically healthy children, using standardized psychometric tests and a specific interview format. We postulated that children with pacemakers would experience greater stress in psychosocial adaptation. No significant differences on standardized measures of trait anxiety, self-competence, or self-esteem were found between the pacemaker group and the comparison groups. In contrast, pacemaker subjects were significantly (p less than 0.05) more external in their locus-of-control orientation than were healthy subjects, suggesting a diminished sense of personal control and less autonomy. Pacemaker subjects, particularly the older ones, had significantly (p less than 0.05) greater knowledge of pacemaker systems than did subjects in the other two groups, facilitating the use of intellectualization as a coping mechanism. The pacemaker patients were likely to be as fearful of social rejection as of potential pacemaker failure. All three groups identified potential negative peer reactions toward an individual with a pacemaker. The patients with cardiac disease but without pacemakers and the healthy subjects perceived significant (p less than 0.05) social and emotional differences between patients with pacemakers and their peers, but the pacemaker patients did not view themselves as different from their peers. This study demonstrates healthy psychosocial adaptation of children with cardiac pacemakers. Although these children appear to cope effectively with the stress of their life situation through the use of denial and intellectualization, they may experience problems both in the development of autonomy and in social isolation and rejection.

Pacemaker rate and depolarization block in nigral dopamine neurons: a somatic sodium channel balancing act

Science.gov (United States)

Tucker, Kristal R.; Huertas, Marco A.; Horn, John P.; Canavier, Carmen C.; Levitan, Edwin S.

2012-01-01

Midbrain dopamine (DA) neurons are slow intrinsic pacemakers that undergo depolarization (DP) block upon moderate stimulation. Understanding DP block is important because it has been correlated with the clinical efficacy of chronic antipsychotic drug treatment. Here we describe how voltage-gated sodium (NaV) channels regulate DP block and pacemaker activity in DA neurons of the substantia nigra using rat brain slices. The distribution, density and gating of NaV currents were manipulated by blocking native channels with tetrodotoxin and by creating virtual channels and anti-channels with dynamic clamp. Although action potentials initiate in the axon initial segment (AIS) and NaV channels are distributed in multiple dendrites, selective reduction of NaV channel activity in the soma was sufficient to decrease pacemaker frequency and increase susceptibility to DP block. Conversely, increasing somatic NaV current density raised pacemaker frequency and lowered susceptibility to DP block. Finally, when NaV currents were restricted to the soma, pacemaker activity occurred at abnormally high rates due to excessive local subthreshold NaV current. Together with computational simulations, these data show that both the slow pacemaker rate and the sensitivity to DP block that characterizes DA neurons result from the low density of somatic NaV channels. More generally, we conclude that the somatodendritic distribution of NaV channels is a major determinant of repetitive spiking frequency. PMID:23077037

Spanish Pacemaker Registry. Twelfth Official Report of the Spanish Society of Cardiology Working Group on Cardiac Pacing (2014).

Science.gov (United States)

Cano Pérez, Óscar; Pombo Jiménez, Marta; Coma Samartín, Raúl

2015-12-01

This report describes the results of the analysis of pacemaker implant and replacement data submitted to the Spanish Pacemaker Registry in 2014, with special reference to pacing mode selection. The report is based on the processing of information provided by the European Pacemaker Patient Identification Card. Information was received from 117 hospitals, with a total of 12 358 cards, representing 34% of estimated activity. Use of conventional generators and resynchronization devices was 784 and 64.4 units per million population, respectively. The mean age of patients receiving an implant was 77.3 years. Men received 59% of implants and 56.4% of replacements. Most patients receiving generator implants and replacements were in the age range 80 to 89 years. Most endocardial leads used were bipolar, and 84.2% had an active fixation system. Pacing was in VVI/R mode despite being in sinus rhythm in 24.7% of patients with sick sinus syndrome and 24% of those with atrioventricular block. The use of pacemaker generators and resynchronization devices per million population continued to increase. Most implanted leads had active fixation and approximately 20% had magnetic resonance imaging protection. Age and sex directly influenced pacing mode selection, which could have been improved in more than 20% of cases. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Radiation effect on implanted pacemakers

International Nuclear Information System (INIS)

Pourhamidi, A.H.

1983-01-01

It was previously thought that diagnostic or therapeutic ionizing radiation did not have an adverse effect on the function of cardiac pacemakers. Recently, however, some authors have reported damaging effect of therapeutic radiation on cardiac pulse generators. An analysis of a recently-extracted pacemaker documented the effect of radiation on the pacemaker pulse generator

Effects of irradiation on the components of implantable pacemakers

International Nuclear Information System (INIS)

Kawamura, Shinji; Ono, Seiji; Kuga, Noriyuki; Shiba, Tooru; Hirose, Tetsuo; Matoba, Masaru

2003-01-01

The purpose of this study was to examine the effects of irradiation on implantable pacemaker components. The pacemaker was divided into three components: lead wire and electrode, battery, and electrical circuit, and each component was irradiated by X-ray and electron beams, respectively. The pacemaker parameters were measured by both telemetry data of the programmer and directly measured data from the output terminal. The following results were obtained. For the lead wire and electrode, there was no effect on the pacemaker function due to irradiation by X-ray and electron beams. In the case of battery irradiation, there was no change in battery voltage or current up to 236 Gy X-ray dose. In the electrical circuit, the pacemaker reverted to the regular beating rate (fixed-rate mode) immediately after the start of X-ray irradiation, and it continued in this mode during irradiation. In patients with their own heartbeat rhythm, changing to the fixed-rate mode may cause dangerous conditions such as ventricular fibrillation. When the accumulated irradiation dose is increased, another failure can be seen in the output voltage of the pacemaker. The pacing output voltage dropped rapidly by about 40% at 30-88 Gy. Decreasing the output voltage results in pacing disorders, and heart failure may occur. In the telemetry data of the programmer, no change in output voltage could be detected, highlighting the difference between telemetry data and actual pacing data. (author)

Damaging effect of therapeutic radiation on programmable pacemakers

International Nuclear Information System (INIS)

Adamec, R.; Haefliger, J.M.; Killisch, J.P.; Niederer, J.; Jaquet, P.

1982-01-01

Two series of present-day pacemakers were tested in vitro with pulsed x-ray radiation. The first series of 12 pacemakers consisted of 10 different types and models of demand pacemakers (VVI). The second series of 13 pacemakers had 9 different types and models of programmable pacemakers. Unlike the first series which showed only mild changes in frequency and pulse width, all but four of the programmable pacemakers presented sudden complete failure after different radiation doses. We conclude that direct pulse radiation at therapeutic levels of programmable pacemakers should be avoided

21 CFR 870.3620 - Pacemaker lead adaptor.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker lead adaptor. 870.3620 Section 870.3620...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3620 Pacemaker lead adaptor. (a) Identification. A pacemaker lead adaptor is a device used to adapt a pacemaker lead so that it...

[Wide QRS tachycardia preceded by pacemaker spikes].

Science.gov (United States)

Romero, M; Aranda, A; Gómez, F J; Jurado, A

2014-04-01

The differential diagnosis and therapeutic management of wide QRS tachycardia preceded by pacemaker spike is presented. The pacemaker-mediated tachycardia, tachycardia fibrillo-flutter in patients with pacemakers, and runaway pacemakers, have a similar surface electrocardiogram, but respond to different therapeutic measures. The tachycardia response to the application of a magnet over the pacemaker could help in the differential diagnosis, and in some cases will be therapeutic, as in the case of a tachycardia-mediated pacemaker. Although these conditions are diagnosed and treated in hospitals with catheterization laboratories using the application programmer over the pacemaker, patients presenting in primary care clinic and emergency forced us to make a diagnosis and treat the haemodynamically unstable patient prior to referral. Copyright © 2012 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

Pacemakers and Implantable Defibrillators: MedlinePlus Health Topic

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... ClinicalTrials.gov: Pacemaker, Artificial (National Institutes of Health) Journal Articles References and abstracts from MEDLINE/PubMed (National ... Leadless Cardiac Pacemakers: The Next Evolution in Pacemaker Technology. ... on Pacemakers and Implantable Defibrillators is the National Heart, Lung, and Blood Institute Other Languages Find health information in languages other than English on Pacemakers and ...

21 CFR 870.3700 - Pacemaker programmers.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker programmers. 870.3700 Section 870.3700...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3700 Pacemaker programmers. (a) Identification. A pacemaker programmer is a device used to change noninvasively one or more of...

On the Evolution of the Cardiac Pacemaker

Directory of Open Access Journals (Sweden)

Silja Burkhard

2017-04-01

Full Text Available The rhythmic contraction of the heart is initiated and controlled by an intrinsic pacemaker system. Cardiac contractions commence at very early embryonic stages and coordination remains crucial for survival. The underlying molecular mechanisms of pacemaker cell development and function are still not fully understood. Heart form and function show high evolutionary conservation. Even in simple contractile cardiac tubes in primitive invertebrates, cardiac function is controlled by intrinsic, autonomous pacemaker cells. Understanding the evolutionary origin and development of cardiac pacemaker cells will help us outline the important pathways and factors involved. Key patterning factors, such as the homeodomain transcription factors Nkx2.5 and Shox2, and the LIM-homeodomain transcription factor Islet-1, components of the T-box (Tbx, and bone morphogenic protein (Bmp families are well conserved. Here we compare the dominant pacemaking systems in various organisms with respect to the underlying molecular regulation. Comparative analysis of the pathways involved in patterning the pacemaker domain in an evolutionary context might help us outline a common fundamental pacemaker cell gene programme. Special focus is given to pacemaker development in zebrafish, an extensively used model for vertebrate development. Finally, we conclude with a summary of highly conserved key factors in pacemaker cell development and function.

On the Evolution of the Cardiac Pacemaker

Science.gov (United States)

Burkhard, Silja; van Eif, Vincent; Garric, Laurence; Christoffels, Vincent M.; Bakkers, Jeroen

2017-01-01

The rhythmic contraction of the heart is initiated and controlled by an intrinsic pacemaker system. Cardiac contractions commence at very early embryonic stages and coordination remains crucial for survival. The underlying molecular mechanisms of pacemaker cell development and function are still not fully understood. Heart form and function show high evolutionary conservation. Even in simple contractile cardiac tubes in primitive invertebrates, cardiac function is controlled by intrinsic, autonomous pacemaker cells. Understanding the evolutionary origin and development of cardiac pacemaker cells will help us outline the important pathways and factors involved. Key patterning factors, such as the homeodomain transcription factors Nkx2.5 and Shox2, and the LIM-homeodomain transcription factor Islet-1, components of the T-box (Tbx), and bone morphogenic protein (Bmp) families are well conserved. Here we compare the dominant pacemaking systems in various organisms with respect to the underlying molecular regulation. Comparative analysis of the pathways involved in patterning the pacemaker domain in an evolutionary context might help us outline a common fundamental pacemaker cell gene programme. Special focus is given to pacemaker development in zebrafish, an extensively used model for vertebrate development. Finally, we conclude with a summary of highly conserved key factors in pacemaker cell development and function. PMID:29367536

21 CFR 870.3670 - Pacemaker charger.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker charger. 870.3670 Section 870.3670 Food... DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3670 Pacemaker charger. (a) Identification. A pacemaker charger is a device used transcutaneously to recharge the batteries of a rechargeable...

What Is a Pacemaker?

Science.gov (United States)

... your pacemaker. • If you work around industrial microwaves, electricity, cars or other large motors, ask your doctor about possible effects. Can I use a cell phone or microwave oven if I have a pacemaker? Microwave ovens, electric blankets, remote controls for TV and other common ...

Pacemaker patients’ perspective and experiences in a pacemaker outpatient clinic in relation to test intervals of the pacemaker

DEFF Research Database (Denmark)

Lauberg, Astrid; Hansen, Tina; Pedersen, Trine Pernille Dahl

an evident decline in quality of life regarding psychological and social aspects 6 month after the implantation in terms of cognitive function, work ability, and sexual activity. Mlynarski et al (2009) have found correlations between pacemaker implantation and anxiety and depression. Aim The aim...... the pacemaker and psychological reactions. Patients with pacemakers older than 3 months lacked communication with fellowmen. Conclusion The patients express receiving competent and professional treatment when visiting the outpatient clinic, there seems to be a discrepancy between the long test intervals...... and the critical period in which anxiety and depression may occur. Minor problems and questions may grow into fatal conditions if the patients are not offered an opportunity to discuss this with experts. Patients are not informed that it is possible to discuss problems that imply psychological topics and they do...

Pacemaker

Science.gov (United States)

... close to a security system metal detector. Notify security staff if you have a pacemaker. Also, stay at least 2 feet away from industrial welders and electrical generators. Some medical procedures can ...

Radiotherapy for breast cancer and pacemaker

International Nuclear Information System (INIS)

Menard, J.; Campana, F.; Bollet, M.A.; Dendale, R.; Fournier-Bidoz, N.; Marchand, V.; Mazal, A.; Fourquet, A.; Kirova, Y.M.; Kirov, K.M.; Esteve, M.

2011-01-01

Purpose. - Patients with permanent cardiac pacemakers occasionally require radiotherapy. Therapeutic Irradiation may cause pacemakers to malfunction due to the effects of ionizing radiation or electromagnetic interference. We studied the breast cancer patients who needed breast and/or chest wall and lymph node irradiation to assess the feasibility and tolerance in this population of patients. Patients and methods. - From November 2008 to December 2009, more than 900 patients received radiotherapy for their breast cancer in our department using megavoltage linear accelerator (X 4-6 MV and electrons). Among them, seven patients were with permanent pacemaker. All patients have been treated to the breast and chest wall and/or lymph nodes. Total dose to breast and/or chest wall was 50 Gy/25 fractions and 46 Gy/23 fractions to lymph nodes. Patients who underwent conserving surgery followed by breast irradiation were boosted when indicated to tumour bed with 16 Gy/8 fractions. All patients were monitored everyday in presence of radiation oncologist to follow the function of their pacemaker. All pacemakers were controlled before and after radiotherapy by the patients' cardiologist. Results. - Seven patients were referred in our department for postoperative breast cancer radiotherapy. Among them, only one patient was declined for radiotherapy and underwent mastectomy without radiotherapy. In four cases the pacemaker was repositioned before the beginning of radiotherapy. Six patients, aged between 48 and 84 years underwent irradiation for their breast cancer. Four patients were treated with conserving surgery followed by breast radiotherapy and two with mastectomy followed by chest wall and internal mammary chain, supra- and infra-clavicular lymph node irradiation. The dose to the pacemaker generator was kept below 2 Gy. There was no pacemaker dysfunction observed during the radiotherapy. Conclusion. - The multidisciplinary work with position change of the pacemaker before

Wireless power transfer for a pacemaker application.

Science.gov (United States)

Vulfin, Vladimir; Sayfan-Altman, Shai; Ianconescu, Reuven

2017-05-01

An artificial pacemaker is a small medical device that uses electrical impulses, delivered by electrodes contracting the heart muscles, to regulate the beating of the heart. The pacemaker is implanted under the skin, and uses for many years regular non-rechargeable batteries. However, the demand for rechargeable batteries in pacemakers increased, and the aim of this work is to design an efficient charging system for pacemakers.

Pacemaker wires

International Nuclear Information System (INIS)

Fransson, S.G.

1993-01-01

Evaluation of pacemaker wires were performed by comparing Advanced Multiple Beam Equalization Radiography (AMBER) with conventional chest radiography. The scanning equalization technique of the AMBER unit makes it superior to conventional technique in the depiction of different structures in the mediastinum or in the pleural sinuses. So far motion artifacts have not been considered clinically important. The longer exposure time, however, may impair the assessment of pacemaker wires. The motion artifact described may not only make adequate evaluation impossible but may even give a false impression of a lead fracture. The difference between the two systems was significant. (orig.)

The nuclear pacemaker: Is renewed interest warranted

International Nuclear Information System (INIS)

Parsonnet, V.; Berstein, A.D.; Perry, G.Y.

1990-01-01

From 1973 through 1987, 155 radioisotope-powered nuclear pacemakers were implanted in 132 patients at the Newark Beth Israel Medical Center. The longevity of the first 15 devices, all of which were fixed-rate (VOO) pacemakers, was significantly better than that of 15 lithium-chemistry demand (VVI) pacemakers used as control devices (p = 0.0002). Of the entire cohort of 155 nuclear pacemakers, 136 were VVI devices and 19 were VOO units. The patients with VOO pacemakers needed reoperations more often than did those with VVI pacemakers, chiefly for mode change (p less than 0.001). Power-source failure was observed in only 1 case, but 47 nuclear pacemakers were removed for other reasons, including component malfunction (15 units), mode change (12 units), high pacing thresholds (8 units) and lead or connector problems (5 units). The actuarial survival at 15 years was 99% for power sources and 82% for the entire pacing systems (pulse generators plus leads). The frequency of malignancy was similar to that of the population at large and primary tumor sites were randomly distributed. Deaths most commonly were due to cardiac causes (68%). Thus, nuclear pacemakers are safe and reliable and their greater initial cost appears to be offset by their longevity and the resulting decrease in the frequency of reoperations. It is reasonable to suggest that further use be made of long-lasting nuclear power sources for modern pacemakers and other implantable rhythm-management devices

Automatic Capture Verification in Pacemakers (Autocapture – Utility and Problems

Directory of Open Access Journals (Sweden)

Ruth Kam

2004-04-01

Full Text Available The concept of a closed – loop feedback system, that would automatically assess pacing threshold and self -adjust pacing output to ensure consistent myocardial capture, has many appeals. Enhancing patient safety in cases of an unexpected rise in threshold, reduced current drain, hence prolonging battery longevity and reducing the amount of physician intervention required are just some of the advantages. Autocapture (AC is a proprietary algorithm developed by St Jude Medical CRMD, Sylmar, CA, USA, (SJM that was the first to commercially provide these automatic functions in a single chamber pacemaker (Microny and Regency, and subsequently in a dual chamber pacemaker (Affinity, Entity and Identity family of pacemakers. This article reviews the conditions necessary for AC verification and performance and the problems encountered in clinical practice.

21 CFR 870.3600 - External pacemaker pulse generator.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External pacemaker pulse generator. 870.3600... pacemaker pulse generator. (a) Identification. An external pacemaker pulse generator is a device that has a... intrinsic pacing sytem until a permanent pacemaker can be implanted, or to control irregular heartbeats in...

Inward-rectifying potassium (Kir) channels regulate pacemaker activity in spinal nociceptive circuits during early life

Science.gov (United States)

Li, Jie; Blankenship, Meredith L.; Baccei, Mark L.

2013-01-01

Pacemaker neurons in neonatal spinal nociceptive circuits generate intrinsic burst-firing and are distinguished by a lower “leak” membrane conductance compared to adjacent, non-bursting neurons. However, little is known about which subtypes of leak channels regulate the level of pacemaker activity within the developing rat superficial dorsal horn (SDH). Here we demonstrate that a hallmark feature of lamina I pacemaker neurons is a reduced conductance through inward-rectifying potassium (Kir) channels at physiological membrane potentials. Differences in the strength of inward rectification between pacemakers and non-pacemakers indicate the presence of functionally distinct Kir currents in these two populations at room temperature. However, Kir currents in both groups showed high sensitivity to block by extracellular Ba2+ (IC50 ~ 10 µM), which suggests the presence of ‘classical’ Kir (Kir2.x) channels in the neonatal SDH. The reduced Kir conductance within pacemakers is unlikely to be explained by an absence of particular Kir2.x isoforms, as immunohistochemical analysis revealed the expression of Kir2.1, Kir2.2 and Kir2.3 within spontaneously bursting neurons. Importantly, Ba2+ application unmasked rhythmic burst-firing in ~42% of non-bursting lamina I neurons, suggesting that pacemaker activity is a latent property of a sizeable population of SDH cells during early life. In addition, the prevalence of spontaneous burst-firing within lamina I was enhanced in the presence of high internal concentrations of free Mg2+, consistent with its documented ability to block Kir channels from the intracellular side. Collectively, the results indicate that Kir channels are key modulators of pacemaker activity in newborn central pain networks. PMID:23426663

Runaway pacemaker: a still existing complication and therapeutic guidelines

DEFF Research Database (Denmark)

Mickley, H; Andersen, C; Nielsen, L H

1989-01-01

Runaway pacemaker is a rare, but still existing potential lethal complication in permanent pacemakers. Within 4 1/2 years, we saw two cases of runaway pacemaker in patients with multiprogrammable, VVI pacemakers (Siemens-Elema, Model 668). In both cases a pacemaker-induced ventricular tachycardia...... pacemaker may be connected to the permanent pacing lead. Thereafter, the lead can be safely cut. As an alternative, a temporary transvenous pacing lead may be established prior to disconnecting the permanent pacing lead....

Eletrocirurgia: sistemas mono e bipolar em cirurgia videolaparoscópica

Directory of Open Access Journals (Sweden)

Manoel Roberto Maciel Trindade

1998-07-01

Full Text Available O conhecimento das leis físicas e dos mecanismos de funcionamento da eletrocirurgia são de grande importância para o cirurgião. Lesões por eletrocirurgia em laparoscopia têm sido observadas, e estão associadas ao uso do eletrodo monopolar, com freqüência de 1 a 2 lesões a cada 1000 procedimentos.Com relação ao desenvolvimento de lesão, existem vários fatores que influenciam: densidade da corrente; o tipo de onda e de coagulação usadas, com suas respectivas voltagens; as condições de isolamento dos dispositivos; a ocorrência do fenômeno de capacitância; e os riscos oferecidos pelo uso em pacientes com marcapasso. No sistema bipolar, a densidade de corrente encontrada ao redor de seus eletrodos é bem menor, levando a menos lesões e, ainda, elimina vários dos outros mecanismos lesivos, como a placa de retorno e os citados acima. Vários estudos demonstram, em colecistectomias, apendicectomias, polipectomias e outros, que o índice de complicações com o eletrodo bipolar é significativamente menor.the knowledge of the physical laws and of the mechanisms of functioning of electrosurgery are of great importance for the surgeon. Lesions caused by electrosurgery in laparoscopic procedures have been observed, and are associated with the use of monopolar electrode, with the frequency of 1 to 2 lesions in every 1000 procedures. Concerning the development of the lesions, several factors are involved; current density, the waveform and the type of coagulation used, with its respective voltages; the insulation condition of the devices; the occurrence of the phenomenon of capacitance and the risks involved with the use in patients with pacemakers. In bipolar electrosurgery, the current density produced around the electrodes is much lower, causing less tissue damage and, still, eliminating several of the other mechanims of injury, such as the dispersive electrode and those quoted above. Several studies reveal that the incidence of

Application of RI power sources to cardiac pacemakers and aftercare in its implantation

International Nuclear Information System (INIS)

Hori, Motokazu

1974-01-01

RI power sources have long life when they are implanted into human bodies together with cardiac pacemakers, as compared with e.g. mercury batteries. Therefore, the frequency of their replacement can be by far less. However, there are the problems of radiation protection, high cost, availability, etc. The following matters are described: The cardiac pacemaker and its power supply, implantation into human body, problems with patients and conventional power sources; the current state of RI power sources for cardiac pacemakers, including plutonium-238 RTG and 147 Pm and 3 H batteries; and problems with the RI power sources. (Mori, K.)

21 CFR 870.3730 - Pacemaker service tools.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker service tools. 870.3730 Section 870.3730...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3730 Pacemaker service tools. (a) Identification. Pacemaker service tools are devices such as screwdrivers and Allen wrenches...

Noise-induced effects on multicellular biopacemaker spontaneous activity: Differences between weak and strong pacemaker cells

Science.gov (United States)

Aghighi, Alireza; Comtois, Philippe

2017-09-01

Self-organization of spontaneous activity of a network of active elements is important to the general theory of reaction-diffusion systems as well as for pacemaking activity to initiate beating of the heart. Monolayer cultures of neonatal rat ventricular myocytes, consisting of resting and pacemaker cells, exhibit spontaneous activation of their electrical activity. Similarly, one proposed approach to the development of biopacemakers as an alternative to electronic pacemakers for cardiac therapy is based on heterogeneous cardiac cells with resting and spontaneously beating phenotypes. However, the combined effect of pacemaker characteristics, density, and spatial distribution of the pacemaker cells on spontaneous activity is unknown. Using a simple stochastic pattern formation algorithm, we previously showed a clear nonlinear dependency of spontaneous activity (occurrence and amplitude of spontaneous period) on the spatial patterns of pacemaker cells. In this study, we show that this behavior is dependent on the pacemaker cell characteristics, with weaker pacemaker cells requiring higher density and larger clusters to sustain multicellular activity. These multicellular structures also demonstrated an increased sensitivity to voltage noise that favored spontaneous activity at lower density while increasing temporal variation in the period of activity. This information will help researchers overcome the current limitations of biopacemakers.

Isotopic cardiac pacemaker during pregnancy. Three cases

International Nuclear Information System (INIS)

Laurens, P.; Gavelle, P.; Maurice, P.; Haiat, R.; Chiche, P.

1976-01-01

Three cases of full term pregnancies, without complications, in women with isotopic pacemakers are reported. The newborn infants were normal. In one case, pregnancy occurred in a patient who already had a pacemaker. In two cases, the pacemaker was inserted during pregnancy (at 1 and 1/2 and 5 months respectively), in the treatment of syncopal attacks due to paroxysmal atrioventricular block. This type of pacemaker using a radioactive source (plutonium 238) is, by virtue of the low degree of radiation, harmless and may be used in women of childbearing age. Under the least favourable conditions (pacemaker box in abdominal situation), the dose delivered during pregnancy (57 mrem) is approximately 20 times less than the authorized dose (1125 mrem) [fr

Effect of germanium concentrations on tunnelling current calculation of Si/Si1-xGex/Si heterojunction bipolar transistor

Science.gov (United States)

Hasanah, L.; Suhendi, E.; Khairrurijal

2018-05-01

Tunelling current calculation on Si/Si1-xGex/Si heterojunction bipolar transistor was carried out by including the coupling between transversal and longitudinal components of electron motion. The calculation results indicated that the coupling between kinetic energy in parallel and perpendicular to S1-xGex barrier surface affected tunneling current significantly when electron velocity was faster than 1x105 m/s. This analytical tunneling current model was then used to study how the germanium concentration in base to Si/Si1-xGex/Si heterojunction bipolar transistor influenced the tunneling current. It is obtained that tunneling current increased as the germanium concentration given in base decreased.

21 CFR 870.3690 - Pacemaker test magnet.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker test magnet. 870.3690 Section 870.3690...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3690 Pacemaker test magnet. (a) Identification. A pacemaker test magnet is a device used to test an inhibited or triggered type...

Low cost bipolar current collector-separator for electrochemical cells

International Nuclear Information System (INIS)

Lawrence, R.

1980-01-01

A bipolar current collecting, cell separating element for electrochemical cells for conducting current from the anode electrode of one cell unit to cathode electrode of the adjacent cell unit comprises: (A) a pressure mold aggregate of electrically conductive carbon/graphite particles and thermoplastic fluorocarbon polymer resin particles in a weight ratio of 2.5:1 to 16:1 whereby said molded aggregated has a bulk resistivity which is less than 4x10 -3 ohm/inch, (B) said molded aggregate having a fluid imprevious main body, at least one recessed chamber on one side of said main body and a plurality of spaced, conductive projections extending from the base of said chamber for contacting and permitting current flow between the electrode of adjacent cell unit, and (C) means communicating with said recessed chambers to permit introduction and removal of fluids

A minimal model for a slow pacemaking neuron

International Nuclear Information System (INIS)

Zakharov, D.G.; Kuznetsov, A.

2012-01-01

Highlights: ► We have constructed a phenomenological model for slow pacemaking neurons. ► The model implements a nonlinearity introduced by an ion-dependent current. ► The new nonlinear dependence allows for differentiating responses to various stimuli. ► We discuss implications of our results for a broad class of neurons. - Abstract: We have constructed a phenomenological model for slow pacemaking neurons. These are neurons that generate very regular periodic oscillations of the membrane potential. Many of these neurons also differentially respond to various types of stimulation. The model is based on FitzHugh–Nagumo (FHN) oscillator and implements a nonlinearity introduced by a current that depends on an ion concentration. The comparison with the original FHN oscillator has shown that the new nonlinear dependence allows for differentiating responses to various stimuli. We discuss implications of our results for a broad class of neurons.

Epithermal neutron beam interference with cardiac pacemakers

International Nuclear Information System (INIS)

Koivunoro, H.; Serén, T.; Hyvönen, H.; Kotiluoto, P.; Iivonen, P.; Auterinen, I.; Seppälä, T.; Kankaanranta, L.; Pakarinen, S.; Tenhunen, M.; Savolainen, S.

2011-01-01

In this paper, a phantom study was performed to evaluate the effect of an epithermal neutron beam irradiation on the cardiac pacemaker function. Severe malfunction occurred in the pacemakers after substantially lower dose from epithermal neutron irradiation than reported in the fast neutron or photon beams at the same dose rate level. In addition the pacemakers got activated, resulting in nuclides with half-lives from 25 min to 115 d. We suggest that BNCT should be administrated only after removal of the pacemaker from the vicinity of the tumor.

Epithermal neutron beam interference with cardiac pacemakers

Energy Technology Data Exchange (ETDEWEB)

Koivunoro, H., E-mail: hanna.koivunoro@helsinki.fi [Department of Physics, P.O.B. 64, FI-00014 University of Helsinki (Finland)] [Department of Oncology, Helsinki University Central Hospital, P.O.B. 180, FIN-00029 HUS (Finland)] [Boneca Corporation, Finland, Filnland (Finland); Seren, T. [VTT Technical Research Centre of Finland (Finland); Hyvoenen, H. [Boneca Corporation, Finland, Filnland (Finland); Kotiluoto, P. [VTT Technical Research Centre of Finland (Finland); Iivonen, P. [St. Jude Medical (Finland); Auterinen, I. [VTT Technical Research Centre of Finland (Finland); Seppaelae, T.; Kankaanranta, L. [Department of Oncology, Helsinki University Central Hospital, P.O.B. 180, FIN-00029 HUS (Finland); Pakarinen, S. [Department of Cardiology, Helsinki University Central Hospital (Finland); Tenhunen, M. [Department of Oncology, Helsinki University Central Hospital, P.O.B. 180, FIN-00029 HUS (Finland); Savolainen, S. [HUS Helsinki Medical Imaging Center, Helsinki University Central Hospital (Finland)

2011-12-15

In this paper, a phantom study was performed to evaluate the effect of an epithermal neutron beam irradiation on the cardiac pacemaker function. Severe malfunction occurred in the pacemakers after substantially lower dose from epithermal neutron irradiation than reported in the fast neutron or photon beams at the same dose rate level. In addition the pacemakers got activated, resulting in nuclides with half-lives from 25 min to 115 d. We suggest that BNCT should be administrated only after removal of the pacemaker from the vicinity of the tumor.

Mechanisms underlying the cardiac pacemaker: the role of SK4 calcium-activated potassium channels.

Science.gov (United States)

Weisbrod, David; Khun, Shiraz Haron; Bueno, Hanna; Peretz, Asher; Attali, Bernard

2016-01-01

The proper expression and function of the cardiac pacemaker is a critical feature of heart physiology. The sinoatrial node (SAN) in human right atrium generates an electrical stimulation approximately 70 times per minute, which propagates from a conductive network to the myocardium leading to chamber contractions during the systoles. Although the SAN and other nodal conductive structures were identified more than a century ago, the mechanisms involved in the generation of cardiac automaticity remain highly debated. In this short review, we survey the current data related to the development of the human cardiac conduction system and the various mechanisms that have been proposed to underlie the pacemaker activity. We also present the human embryonic stem cell-derived cardiomyocyte system, which is used as a model for studying the pacemaker. Finally, we describe our latest characterization of the previously unrecognized role of the SK4 Ca(2+)-activated K(+) channel conductance in pacemaker cells. By exquisitely balancing the inward currents during the diastolic depolarization, the SK4 channels appear to play a crucial role in human cardiac automaticity.

21 CFR 870.3640 - Indirect pacemaker generator function analyzer.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Indirect pacemaker generator function analyzer... Indirect pacemaker generator function analyzer. (a) Identification. An indirect pacemaker generator function analyzer is an electrically powered device that is used to determine pacemaker function or...

The influence of radiation therapy on cardiac pacemakers

International Nuclear Information System (INIS)

Coles, J.R.; Ciddor, G.S.

1980-01-01

The results of an investigation to determine the influence on pacemaking of ionizing radiation and electromagnetic radiation from a number of radiotherapy machines are reported. In vitro tests were carried out on unipolar cardiac pacemakers of the ventricular inhibited type. The pacemakers were largely unaffected by the environment of clinical radiotherapy machines. Ionizing radiation had no detrimental effect on the pacemakers and electromagnetic interference caused only temporary single-beat inhibition at most. With the betatron used, malfunction of the pacemakers regularly occurred whilst in their inhibited made of operation. The demand function became disabled allowing competitive asynchronous pulses to be produced

Pacemaker syndrome with sub-acute left ventricular systolic dysfunction in a patient with a dual-chamber pacemaker: consequence of lead switch at the header.

Science.gov (United States)

Khurwolah, Mohammad Reeaze; Vezi, Brian Zwelethini

In the daily practice of pacemaker insertion, the occurrence of atrial and ventricular lead switch at the pacemaker box header is a rare and unintentional phenomenon, with less than five cases reported in the literature. The lead switch may have dire consequences, depending on the indication for the pacemaker. One of these consequences is pacemaker syndrome, in which the normal sequence of atrial and ventricular activation is impaired, leading to sub-optimal ventricular filling and cardiac output. It is important for the attending physician to recognise any worsening of symptoms in a patient who has recently had a permanent pacemaker inserted. In the case of a dual-chamber pacemaker, switching of the atrial and ventricular leads at the pacemaker box header should be strongly suspected. We present an unusual case of pacemaker syndrome and right ventricular-only pacinginduced left ventricular systolic dysfunction in a patient with a dual-chamber pacemaker.

Hardware and Software of a Bipolar Current Source Controlled by PC

Directory of Open Access Journals (Sweden)

Mirjana Rajčić-Vujasinović

2008-03-01

Full Text Available This paper describes a realization of a bipolar current source developed by the paper's authors. The source is intended for use in galvanic and other industrial plants, where a pulse-reverse current supply (with the desired shape in time is required. A prototype of the device, which provides the outcome current intensity up to ± 50 A, has been constructed. The hardware of the source consists of a Pentium IV PC, a commercial ADDA converter, an interface of authors’ original construction as well as a current regulator. The application software is developed using a commercial packet LabView as the basis.

Proton Beam Therapy Interference With Implanted Cardiac Pacemakers

International Nuclear Information System (INIS)

Oshiro, Yoshiko; Sugahara, Shinji; Noma, Mio; Sato, Masato; Sakakibara, Yuzuru; Sakae, Takeji; Hayashi, Yasutaka; Nakayama, Hidetsugu; Tsuboi, Koji; Fukumitsu, Nobuyoshi; Kanemoto, Ayae; Hashimoto, Takayuki; Tokuuye, Koichi

2008-01-01

Purpose: To investigate the effect of proton beam therapy (PBT) on implanted cardiac pacemaker function. Methods and Materials: After a phantom study confirmed the safety of PBT in patients with cardiac pacemakers, we treated 8 patients with implanted pacemakers using PBT to a total tumor dose of 33-77 gray equivalents (GyE) in dose fractions of 2.2-6.6 GyE. The combined total number of PBT sessions was 127. Although all pulse generators remained outside the treatment field, 4 patients had pacing leads in the radiation field. All patients were monitored by means of electrocardiogram during treatment, and pacemakers were routinely examined before and after PBT. Results: The phantom study showed no effect of neutron scatter on pacemaker generators. In the study, changes in heart rate occurred three times (2.4%) in 2 patients. However, these patients remained completely asymptomatic throughout the PBT course. Conclusions: PBT can result in pacemaker malfunctions that manifest as changes in pulse rate and pulse patterns. Therefore, patients with cardiac pacemakers should be monitored by means of electrocardiogram during PBT

The influence of current mood state, number of previous affective episodes and predominant polarity on insight in bipolar disorder.

Science.gov (United States)

de Assis da Silva, Rafael; Mograbi, Daniel C; Camelo, Evelyn Vieira Miranda; Peixoto, Ursula; Santana, Cristina Maria Teixeira; Landeira-Fernandez, Jesus; Morris, Robin G; Cheniaux, Elie

2017-11-01

Although many studies have explored the effect of current affective episodes on insight into bipolar disorder, the potential interaction between current mood state and previous affective episodes has not been consistently investigated. To explore the influence of dominant polarity, number of previous affective episodes and current affective state on insight in bipolar disorder patients in euthymia or mania. A total of 101 patients with bipolar disorder were recruited for the study, including 58 patients in euthymia (30 with no defined predominant polarity and 28 with manic predominant polarity) and 43 in mania (26 with no defined predominant polarity and 17 with manic predominant polarity). Patients underwent a clinical assessment and insight was evaluated through the Insight Scale for Affective Disorders. Bipolar disorder patients in mania had worse insight than those in euthymia, with no effect of dominant polarity. In addition, positive psychotic symptoms showed a significant effect on insight and its inclusion as a covariate eliminated differences related to mood state. Finally, the number of previous manic or depressive episodes did not correlate with insight level. Mania is a predictor of loss of insight into bipolar disorder. However, it is possible that its contribution is linked to the more frequent presence of psychotic symptoms in this state. Dominant polarity and number/type of previous affective episodes have a limited impact on insight.

Bipolar Disorder in Children

Science.gov (United States)

2014-01-01

Although bipolar disorder historically was thought to only occur rarely in children and adolescents, there has been a significant increase in children and adolescents who are receiving this diagnosis more recently (Carlson, 2005). Nonetheless, the applicability of the current bipolar disorder diagnostic criteria for children, particularly preschool children, remains unclear, even though much work has been focused on this area. As a result, more work needs to be done to further the understanding of bipolar symptoms in children. It is hoped that this paper can assist psychologists and other health service providers in gleaning a snapshot of the literature in this area so that they can gain an understanding of the diagnostic criteria and other behaviors that may be relevant and be informed about potential approaches for assessment and treatment with children who meet bipolar disorder criteria. First, the history of bipolar symptoms and current diagnostic criteria will be discussed. Next, assessment strategies that may prove helpful for identifying bipolar disorder will be discussed. Then, treatments that may have relevance to children and their families will be discussed. Finally, conclusions regarding work with children who may have a bipolar disorder diagnosis will be offered. PMID:24800202

Pacemakers and implantable cardioverter defibrillators - general and anesthetic considerations

Directory of Open Access Journals (Sweden)

Amy G. Rapsang

2014-06-01

Full Text Available A pacemaking system consists of an impulse generator and lead or leads to carry the electrical impulse to the patient's heart. Pacemaker and implantable cardioverter defibrillator codes were made to describe the type of pacemaker or implantable cardioverter defibrillator implanted. Indications for pacing and implantable cardioverter defibrillator implantation were given by the American College of Cardiologists. Certain pacemakers have magnet-operated reed switches incorporated; however, magnet application can have serious adverse effects; hence, devices should be considered programmable unless known otherwise. When a device patient undergoes any procedure (with or without anesthesia, special precautions have to be observed including a focused history/physical examination, interrogation of pacemaker before and after the procedure, emergency drugs/temporary pacing and defibrillation, reprogramming of pacemaker and disabling certain pacemaker functions if required, monitoring of electrolyte and metabolic disturbance and avoiding certain drugs and equipments that can interfere with pacemaker function. If unanticipated device interactions are found, consider discontinuation of the procedure until the source of interference can be eliminated or managed and all corrective measures should be taken to ensure proper pacemaker function should be done. Post procedure, the cardiac rate and rhythm should be monitored continuously and emergency drugs and equipments should be kept ready and consultation with a cardiologist or a pacemaker-implantable cardioverter defibrillator service may be necessary.

Direct Current Combined With Bipolar Radiofrequency Ablation: An Ex Vivo Feasibility Study

International Nuclear Information System (INIS)

Tanaka, Toshihiro; Penzkofer, Tobias; Isfort, Peter; Bruners, Philipp; Disselhorst-Klug, Catherine; Junker, Elmar; Kichikawa, Kimihiko; Schmitz-Rode, Thomas; Mahnken, Andreas H.

2011-01-01

The combination of radiofrequency ablation (RFA) with direct current (DC) is a promising strategy to improve the efficiency of RFA. However, DC-enhanced monopolar RFA is limited by electrolytic injury at the positive-electrode site. The aim of this study was to investigate the feasibility of the DC-enhanced bipolar RFA. To obviate the need for the subcutaneous positive electrode, the DC circuit was combined with a commercially available bipolar RFA system, in which both poles of the DC circuit are connected to a single RF probe. DC was applied for 15 min and followed by RFA in bovine livers using the following various DC currents: (1) no DC (control), (2) 3V continued until the end of RFA, (3) 5V continued until the end of RFA, (4) 10V continued until the end of RFA, (5) 5V continued in the circuit with reversed pole, (6) 3V stopped after initiation of RFA, and (7) 5V stopped. Coagulation volume, temperatures at a distance of 5, 10, and 15 mm from the RF probe, mean amperage, ablation duration, applied energy, minimum impedance, and degree of tissue charring were assessed and compared (analysis of variance, Student–Newman–Keuls test). All combined DC and RFA groups did increase coagulation volume. The 10V continued group showed significantly lower applied energy, shortest ablation duration, highest minimum impedance, and highest degree of charring with the lowest coagulation volume (p < 0.05). DC-enhanced bipolar RFA with both poles of the DC circuit on a single probe appears to be ineffective.

Interference with cardiac pacemakers by magnetic resonance imaging: are there irreversible changes at 0.5 Tesla?

Science.gov (United States)

Vahlhaus, C; Sommer, T; Lewalter, T; Schimpf, R; Schumacher, B; Jung, W; Lüderitz, B

2001-04-01

The safety and feasibility of magnetic resonance imaging (MRI) in patients with cardiac pacemakers is an issue of gaining significance. The effect of MRI on patients' pacemaker systems has only been analyzed retrospectively in some case reports. Therefore, this study prospectively investigated if MRI causes irreversible changes in patients' pacemaker systems. The effect of MRI at 0.5 Tesla on sensing and stimulation thresholds, lead impedance and battery voltage, current, and impedance was estimated during 34 MRI examinations in 32 patients with implanted pacemakers. After measurements at baseline and with documentation of intrinsic rhythm and modification of the pacing mode, patients underwent MRI. The rest of the function time of the pacemaker was calculated. Measurements were again performed after 99.5 +/- 29.6 minutes (mean +/- SD), immediately after MRI examination, and 3 months later. Lead impedance and sensing and stimulation thresholds did not change after MRI. Battery voltage decreased immediately after MRI and recovered 3 months later. Battery current and impedance tended to increase. The calculated rest of function time did not change immediately after MRI. MRI affected neither pacemaker programmed data, nor the ability to interrogate, program, or use telemetry. Surprisingly, in the gantry of the scanner, temporary deactivation of the reed switch occurred in 12 of 32 patients when positioned in the center of the magnetic field. Missing activation of the reed switch through the static magnetic field at 0.5 Tesla is not unusual. MRI at 0.5 Tesla does not cause irreversible changes in patients' pacemaker systems.

1978 Pacemaker Newspaper Awards: What Makes a Pacemaker?

Science.gov (United States)

Brasler, Wayne

1979-01-01

Lists the nine high school and college newspapers, and the one newsmagazine, that won Pacemaker Awards in 1978; discusses characteristics that make each of them outstanding, and provides reproductions of a front page from each publication. (GT)

Biofilm on artificial pacemaker: fiction or reality?

Science.gov (United States)

Santos, Ana Paula Azevedo; Watanabe, Evandro; Andrade, Denise de

2011-11-01

Cardiac pacing through cardiac pacemaker is one of the most promising alternatives in the treatment of arrhythmias, but it can cause reactions natural or complex reactions, either early or late. This study aimed to describe the scientific evidence on the risk of infection and biofilm formation associated with cardiac pacemaker. This is a study of integrative literature review. It included 14 publications classified into three thematic categories: diagnosis (microbiological and/or clinical), complications and therapy of infections. Staphylococcus epidermidis and Staphylococcus aureus were the microorganisms most frequently isolated. It was not possible to determine the incidence of infection associated with pacemakers, since the studies were generally of prevalence. In terms of therapy, the complete removal of pacemakers stood out, especially in cases of suspected biofilm. Still controversial is the use of systemic antibiotic prophylaxis in reducing the incidence of infection associated with implantation of a pacemaker.

Pacemaker therapy in low-birth-weight infants.

Science.gov (United States)

Fuchigami, Tai; Nishioka, Masahiko; Akashige, Toru; Shimabukuro, Atsuya; Nagata, Nobuhiro

2018-02-01

Infants born with complete atrioventricular block (CAVB) and fetal bradycardia are frequently born with low birth weight. Three low-birth-weight CAVB infants underwent temporary pacemaker implantation, followed by permanent single-chamber pacemaker implantation at median body weights of 1.7 and 3.2 kg, respectively. All infants caught up with their growth curves and had >3 years of estimated residual battery life. This two-stage strategy was successful in facilitating permanent pacemaker implantation in low-birth-weight babies. Placement of single-chamber pacemaker on the apex of the left ventricle appears to be associated with longer battery lifespan. © 2018 Wiley Periodicals, Inc.

21 CFR 870.3720 - Pacemaker electrode function tester.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker electrode function tester. 870.3720... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3720 Pacemaker electrode function tester. (a) Identification. A pacemaker electrode function tester is a device which is...

21 CFR 870.3630 - Pacemaker generator function analyzer.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker generator function analyzer. 870.3630... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3630 Pacemaker generator function analyzer. (a) Identification. A pacemaker generator function analyzer is a device that is...

The clinical trajectory of emerging bipolar disorder among the high-risk offspring of bipolar parents: current understanding and future considerations.

Science.gov (United States)

Duffy, A; Vandeleur, C; Heffer, N; Preisig, M

2017-11-22

Relatively little is known about the onset of bipolar disorder, yet the early illness course is already associated with significant morbidity and mortality. Therefore, characterizing the bipolar illness trajectory is key to risk prediction and early intervention advancement. In this narrative review, we discuss key findings from prospective longitudinal studies of the high-risk offspring of bipolar parents and related meta-analyses that inform us about the clinical trajectory of emerging bipolar disorder. Challenges such as phenotypic and etiologic heterogeneity and the non-specificity of early symptoms and syndromes are highlighted. Implications of the findings for both research and clinical practice are discussed. Bipolar disorder in young people at familial risk does not typically onset with a hypomanic or manic episode. Rather the first activated episode is often preceded by years of impairing psychopathological states that vary over development and across emerging bipolar subtype. Taking heterogeneity into account and adopting a more comprehensive approach to diagnosis seems necessary to advance earlier identification and our understanding of the onset of bipolar disorder.

Synchronization of Coupled Neurons Controlled by a Pacemaker

International Nuclear Information System (INIS)

Li Mei-Sheng; Zhang Hong-Hui; Zhao Yong; Shi Xia

2011-01-01

We investigate synchronization of Hindmarsh—Rose neurons with gap junctions under the control of a pacemaker. In a ring Hindmarsh—Rose neuronal network, the coupled neurons with the pacemaker can occur in synchronization more easily than those without the pacemaker. Furthermore, the pacemaker can induce phase synchronization or nearly-complete synchronization of nonidentical neurons. This synchronization can occur more easily when time delay is considered. Theses results can be helpful to understand the activities of the real neuronal system. (general)

Spiral–pacemaker interactions in a mathematical model of excitable medium

International Nuclear Information System (INIS)

Shajahan, T K; Borek, Bartłomiej; Shrier, Alvin; Glass, Leon

2013-01-01

Interactions of a spiral wave with a pacemaker is studied in a mathematical model of two dimensional excitable medium. Faster pacemakers emitting target waves can abolish spirals by driving them to the border of the medium. Our study shows that a slower pacemaker can modify spiral wave behavior by changing the motion of the spiral core. We analyze the dynamics of the spiral wave near the spiral core and away from the core as a function of size and period of the pacemaker. The pacemaker can cause the spiral wave to drift towards it, and either speed up or slow down the reentrant activity. Furthermore, the drift induced by the pacemaker can result in irregular or quasiperiodic dynamics even at sites away from the pacemaker. These results highlight the influence of pacemakers on complex spiral wave dynamics. (paper)

21 CFR 870.3610 - Implantable pacemaker pulse generator.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implantable pacemaker pulse generator. 870.3610 Section 870.3610 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... pacemaker pulse generator. (a) Identification. An implantable pacemaker pulse generator is a device that has...

21 CFR 870.3650 - Pacemaker polymeric mesh bag.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker polymeric mesh bag. 870.3650 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3650 Pacemaker polymeric mesh bag. (a) Identification. A pacemaker polymeric mesh bag is an implanted device used to hold a...

Cytokines in bipolar disorder

DEFF Research Database (Denmark)

Munkholm, Klaus; Vinberg, Maj; Vedel Kessing, Lars

2012-01-01

BACKGROUND: Current research and hypothesis regarding the pathophysiology of bipolar disorder suggests the involvement of immune system dysfunction that is possibly related to disease activity. Our objective was to systematically review evidence of cytokine alterations in bipolar disorder according...... to affective state. METHODS: We conducted a systemtic review of studies measuring endogenous cytokine concentrations in patients with bipolar disorder and a meta-analysis, reporting results according to the PRISMA statement. RESULTS: Thirteen studies were included, comprising 556 bipolar disorder patients...

Radiation therapy in patients with electric cardiac pacemakers

International Nuclear Information System (INIS)

Bisping, H.J.; Stockberg, H.; Meyer, J.; Frik, W.; Technische Hochschule Aachen

1977-01-01

In the course of radiation therapy and connected diagnostic measures ionizing radiation and other sources of disturbance may interfere with the function of permanent pacemakers. The conditions of such hazards are investigated in theory and practice making allowance for the different susceptibility to trouble of various models of permanent pacemakers. It appears that no extension of long-term follow-up of the cardiac pacemaker's function is needed with regard to possible late effects of ionizing radiation, but that the follow-up of pacemaker-patients during their first period of treatment should not be neglected, since other sources of electronic interference may be present. Routine checks at radiotherapy installations should also include possible sources of disturbance to electronic pacemakers. (orig.) [de

21 CFR 870.3680 - Cardiovascular permanent or temporary pacemaker electrode.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiovascular permanent or temporary pacemaker... § 870.3680 Cardiovascular permanent or temporary pacemaker electrode. (a) Temporary pacemaker electrode—(1) Identification. A temporary pacemaker electrode is a device consisting of flexible insulated...

Current density and catalyst-coated membrane resistance distribution of hydro-formed metallic bipolar plate fuel cell short stack with 250 cm2 active area

Science.gov (United States)

Haase, S.; Moser, M.; Hirschfeld, J. A.; Jozwiak, K.

2016-01-01

An automotive fuel cell with an active area of 250 cm2 is investigated in a 4-cell short stack with a current and temperature distribution device next to the bipolar plate with 560 current and 140 temperature segments. The electrical conductivities of the bipolar plate and gas diffusion layer assembly are determined ex-situ with this current scan shunt module. The applied fuel cell consists of bipolar plates constructed of 75-μm-thick, welded stainless-steel foils and a graphitic coating. The electrical conductivities of the bipolar plate and gas diffusion layer assembly are determined ex-situ with this module with a 6% deviation in in-plane conductivity. The current density distribution is evaluated up to 2.4 A cm-2. The entire cell's investigated volumetric power density is 4.7 kW l-1, and its gravimetric power density is 4.3 kW kg-1 at an average cell voltage of 0.5 V. The current density distribution is determined without influencing the operating cell. In addition, the current density distribution in the catalyst-coated membrane and its effective resistivity distribution with a finite volume discretisation of Ohm's law are evaluated. The deviation between the current density distributions in the catalyst-coated membrane and the bipolar plate is determined.

Impact of Pacemaker Lead Characteristics on Pacemaker Related Infection and Heart Perforation: A Nationwide Population-Based Cohort Study.

Science.gov (United States)

Lin, Yu-Sheng; Chen, Tien-Hsing; Hung, Sheng-Ping; Chen, Dong Yi; Mao, Chun-Tai; Tsai, Ming-Lung; Chang, Shih-Tai; Wang, Chun-Chieh; Wen, Ming-Shien; Chen, Mien-Cheng

2015-01-01

Several risk factors for pacemaker (PM) related complications have been reported. However, no study has investigated the impact of lead characteristics on pacemaker-related complications. Patients who received a new pacemaker implant from January 1997 to December 2011 were selected from the Taiwan National Health Insurance Database. This population was grouped according to the pacemaker lead characteristics in terms of fixation and insulation. The impact of the characteristics of leads on early heart perforation was analyzed by multivariable logistic regression analysis, while the impact of the lead characteristics on early and late infection and late heart perforation over a three-year period were analyzed using Cox regression. This study included 36,104 patients with a mean age of 73.4±12.5 years. In terms of both early and late heart perforations, there were no significant differences between groups across the different types of fixation and insulations. In the multivariable Cox regression analysis, the pacemaker-related infection rate was significantly lower in the active fixation only group compared to either the both fixation (OR, 0.23; 95% CI, 0.07-0.80; P = 0.020) or the passive fixation group (OR, 0.26; 95% CI, 0.08-0.83; P = 0.023). There was no difference in heart perforation between active and passive fixation leads. Active fixation leads were associated with reduced risk of pacemaker-related infection.

Impact of Pacemaker Lead Characteristics on Pacemaker Related Infection and Heart Perforation: A Nationwide Population-Based Cohort Study.

Directory of Open Access Journals (Sweden)

Yu-Sheng Lin

Full Text Available Several risk factors for pacemaker (PM related complications have been reported. However, no study has investigated the impact of lead characteristics on pacemaker-related complications.Patients who received a new pacemaker implant from January 1997 to December 2011 were selected from the Taiwan National Health Insurance Database. This population was grouped according to the pacemaker lead characteristics in terms of fixation and insulation. The impact of the characteristics of leads on early heart perforation was analyzed by multivariable logistic regression analysis, while the impact of the lead characteristics on early and late infection and late heart perforation over a three-year period were analyzed using Cox regression. This study included 36,104 patients with a mean age of 73.4±12.5 years. In terms of both early and late heart perforations, there were no significant differences between groups across the different types of fixation and insulations. In the multivariable Cox regression analysis, the pacemaker-related infection rate was significantly lower in the active fixation only group compared to either the both fixation (OR, 0.23; 95% CI, 0.07-0.80; P = 0.020 or the passive fixation group (OR, 0.26; 95% CI, 0.08-0.83; P = 0.023.There was no difference in heart perforation between active and passive fixation leads. Active fixation leads were associated with reduced risk of pacemaker-related infection.

Wenckebach upper rate response in single chamber pacemaker.

Science.gov (United States)

Barold, S S

2000-07-01

The Medtronic Minix pacemaker during normal function in the VVT mode was found to exhibit a Wenckenbach upper rate response similar to that of dual chamber devices. This behavior occurred only when the upper rate interval was longer than the pacemaker refractory period. In a single chamber device this response may simulate pacemaker malfunction.

A pacemaker powered by an implantable biofuel cell operating under conditions mimicking the human blood circulatory system--battery not included.

Science.gov (United States)

Southcott, Mark; MacVittie, Kevin; Halámek, Jan; Halámková, Lenka; Jemison, William D; Lobel, Robert; Katz, Evgeny

2013-05-07

Biocatalytic electrodes made of buckypaper were modified with PQQ-dependent glucose dehydrogenase on the anode and with laccase on the cathode and were assembled in a flow biofuel cell filled with serum solution mimicking the human blood circulatory system. The biofuel cell generated an open circuitry voltage, Voc, of ca. 470 mV and a short circuitry current, Isc, of ca. 5 mA (a current density of 0.83 mA cm(-2)). The power generated by the implantable biofuel cell was used to activate a pacemaker connected to the cell via a charge pump and a DC-DC converter interface circuit to adjust the voltage produced by the biofuel cell to the value required by the pacemaker. The voltage-current dependencies were analyzed for the biofuel cell connected to an Ohmic load and to the electronic loads composed of the interface circuit, or the power converter, and the pacemaker to study their operation. The correct pacemaker operation was confirmed using a medical device - an implantable loop recorder. Sustainable operation of the pacemaker was achieved with the system closely mimicking human physiological conditions using a single biofuel cell. This first demonstration of the pacemaker activated by the physiologically produced electrical energy shows promise for future electronic implantable medical devices powered by electricity harvested from the human body.

Modern Perspectives on Numerical Modeling of Cardiac Pacemaker Cell

Science.gov (United States)

Maltsev, Victor A.; Yaniv, Yael; Maltsev, Anna V.; Stern, Michael D.; Lakatta, Edward G.

2015-01-01

Cardiac pacemaking is a complex phenomenon that is still not completely understood. Together with experimental studies, numerical modeling has been traditionally used to acquire mechanistic insights in this research area. This review summarizes the present state of numerical modeling of the cardiac pacemaker, including approaches to resolve present paradoxes and controversies. Specifically we discuss the requirement for realistic modeling to consider symmetrical importance of both intracellular and cell membrane processes (within a recent “coupled-clock” theory). Promising future developments of the complex pacemaker system models include the introduction of local calcium control, mitochondria function, and biochemical regulation of protein phosphorylation and cAMP production. Modern numerical and theoretical methods such as multi-parameter sensitivity analyses within extended populations of models and bifurcation analyses are also important for the definition of the most realistic parameters that describe a robust, yet simultaneously flexible operation of the coupled-clock pacemaker cell system. The systems approach to exploring cardiac pacemaker function will guide development of new therapies, such as biological pacemakers for treating insufficient cardiac pacemaker function that becomes especially prevalent with advancing age. PMID:24748434

Waiting for a pacemaker

DEFF Research Database (Denmark)

Risgaard, Bjarke; Elming, Hanne; Jensen, Gunnar

2012-01-01

AIMS: To determine waiting period-related morbidity, mortality, and adverse events in acute patients waiting for a permanent pacemaker (PPM).METHODS AND RESULTS: A retrospective chart review of all PPM implantations in Region Zealand, Denmark, in 2009 was conducted. Patients were excluded...... at least one adverse event during the waiting period. The present study indicates that a waiting period is dangerous as it is associated with an increased risk of adverse events. Acute PPMs should be implanted with a 24-h pacemaker implantation service capacity....

Transcatheter leadless pacemaker implantation in a patient with a transvenous dual-chamber pacemaker already in place.

Science.gov (United States)

Karjalainen, Pasi P; Nammas, Wail; Paana, Tuomas

2016-01-01

An 83-year-old lady had a DDDR pacemaker inserted in 1997 for symptomatic atrioventricular block. She underwent battery replacement in 2008. In 2010, she developed atrial fibrillation; the pacemaker was switched to VVIR mode. During the last 2years, ventricular lead threshold increased progressively. In December 2015, she presented for elective battery replacement. After successful battery replacement, the ventricular lead threshold remained high; therefore, we implanted a leadless transcatheter pacemaker, via femoral vein access, using a dedicated catheter delivery system. Electrical measurements at this stage revealed a pacing threshold of 0.28V at 0.24msec, and an impedance of 650Ω. Copyright © 2016 Elsevier Inc. All rights reserved.

Pacemaker implantation complication rates in elderly and young patients

Directory of Open Access Journals (Sweden)

Özcan KS

2013-08-01

Full Text Available Kazim Serhan Özcan, Damirbek Osmonov, Servet Altay, Cevdet Dönmez, Ersin Yildirim, Ceyhan Türkkan, Baris Güngör, Ahmet Ekmekçi, Ahmet Taha Alper, Kadir Gürkan, İzzet ErdinlerDepartment of Cardiology, Siyami Ersek Cardiovascular and Thoracic Surgery Center, Istanbul, TurkeyAims: To evaluate the complication rate differences between elderly and younger patients who receive a permanent pacemaker implantation.Methods: We reviewed all cases admitted to our institution between January 2008 and June 2009 with symptomatic bradyarrhythmia for whom a permanent pacemaker was implanted. Beginning in June 2009, we prospectively collected data from all patients with the same diagnosis and procedure. The frequency of complications due to the pacemaker implantation procedure was evaluated and compared between young (<70 years old and elderly (≥70 years old patients.Results: Among 574 patients with a permanent pacemaker, 259 patients (45.1% were below and 315 patients (54.9% were above or at 70 years of age. There were 240 (92.7% and 19 (7.3% dual-chamber pacemaker (DDD and single-chamber pacemaker (VVI implanted patients in the younger group, and 291 (76.8% and 73 (23.2% DDD and VVI pacemaker implanted patients in the elderly group, respectively. The complication rate was 39 (15.1% out of 259 young patients and 24 (7.6% out of 315 elderly patients. Postprocedural complications were statistically lower in the elderly patients than in younger patients (P = 0.005.Conclusion: A pacemaker implantation performed by an experienced operator is a safe procedure for patients of advanced age. The patients who are above 70 years old may have less complication rates than the younger patients.Keywords: complications of pacemaker implantation, elderly patients, permanent pacemaker

Modulation of Pacemaker Potentials in Murine Small Intestinal Interstitial Cells of Cajal by Gamisoyo-San, a Traditional Chinese Herbal Medicine.

Science.gov (United States)

Kim, Doeun; Kim, Jung Nam; Nam, Joo Hyun; Lee, Jong Rok; Kim, Sang Chan; Kim, Byung Joo

2018-04-19

The Gamisoyo-san (GSS) has been used for -improving the gastrointestinal (GI) symptoms. The purpose of this study was to investigate the effects of GSS, a traditional Chinese herbal medicine, on the pacemaker potentials of mouse small intestinal interstitial cells of Cajal (ICCs). ICCs from the small intestines were dissociated and cultured. Whole-cell patch-clamp configuration was used to record pacemaker potentials and membrane currents. GSS depolarized ICC pacemaker potentials in a dose-dependent manner. Pretreatment with 4-diphenylacetoxypiperidinium iodide completely inhibited GSS-induced pacemaker potential depolarizations. Intracellular GDP-β-S inhibited GSS-induced effects, and in the presence of U-73122, GSS-induced effects were inhibited. Also, GSS in the presence of a Ca2+-free solution or thapsigargin did not depolarize pacemaker potentials. However, in the presence of calphostin C, GSS slightly depolarized pacemaker potentials. Furthermore, GSS inhibited both transient receptor potential melastatin7 and Ca2+-activated Cl- channel (anoctamin1) currents. GSS depolarized pacemaker potentials of ICCs via G protein and muscarinic M3 receptor signaling pathways and through internal or external Ca2+-, phospholipase C-, and protein kinase C-dependent and transient receptor potential melastatin 7-, and anoctamin 1-independent pathways. The study shows that GSS may regulate GI tract motility, suggesting that GSS could be a basis for developing novel prokinetic agents for treating GI motility dysfunctions. © 2018 S. Karger AG, Basel.

21 CFR 870.5550 - External transcutaneous cardiac pacemaker (noninvasive).

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External transcutaneous cardiac pacemaker... § 870.5550 External transcutaneous cardiac pacemaker (noninvasive). (a) Identification. An external transcutaneous cardiac pacemaker (noninvasive) is a device used to supply a periodic electrical pulse intended to...

21 CFR 870.3710 - Pacemaker repair or replacement material.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is an...

21 CFR 870.1750 - External programmable pacemaker pulse generator.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External programmable pacemaker pulse generator. 870.1750 Section 870.1750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... External programmable pacemaker pulse generator. (a) Identification. An external programmable pacemaker...

Radioisotope-powered cardiac pacemaker program. Clinical studies of the nuclear pacemaker model NU-5. Final report

International Nuclear Information System (INIS)

1980-06-01

Beginning in February, 1970, the Nuclear Materials and Equipment Corporation (NUMEC) undertook a program to design, develop and manufacture a radioisotope powered cardiac pacemaker system. The scope of technical work was specified to be: establish system, component, and process cost reduction goals using the prototype Radioisotope Powered Cardiac Pacemaker (RCP) design and develop production techniques to achieve these cost reduction objectives; fabricate radioisotope powered fueled prototype cardiac pacemakers (RCP's) on a pilot production basis; conduct liaison with a Government-designated fueling facility for purposes of defining fueling requirements, fabrication and encapsulation procedures, safety design criteria and quality control and inspection requirements; develop and implement Quality Assurance and Reliability Programs; conduct performance, acceptance, lifetime and reliability tests of fueled RCP's in the laboratory; conduct liaison with the National Institutes of Health and with Government specified medical research institutions selected for the purpose of undertaking clinical evaluation of the RCP in humans; monitor and evaluate, on a continuing basis, all test data; and perform necessary safety analyses and tests. Pacemaker designs were developed and quality assurance and manufacturing procedures established. Prototype pacemakers were fabricated. A total of 126 radioisotope powered units were implanted and have been followed clinically for approximately seven years. Four (4) of these units have failed. Eighty-three (83) units remain implanted and satisfactorily operational. An overall failure rate of less than the target 0.15% per month has been achieved

Cardiovascular patients’ experiences of living with pacemaker: Qualitative study

Directory of Open Access Journals (Sweden)

Morteza Ghojazadeh

2015-09-01

Full Text Available BACKGROUND: A pacemaker implantation is considered major life event for cardiovascular patients, so they will probably have very interesting experiences of living with this device. The aim of this study was to explore the experiences of cardiovascular patients living with the pacemaker. METHODS: In this qualitative study, 27 patients were chosen through purposive sampling to achieve data saturation, and their experiences were examined using semi-structured interviews. The patients’ statements were recorded with their consent and analyzed using content analysis method. RESULTS: Participants’ experiences included three main themes: “Problems and limitations,” “feeling and dealing with pacemaker”, and “sources of comfort” and 10 sub-themes including: physical problems, financial problems, social problems, the first encounter, the feeling of living with the pacemaker, how to cope with pacemaker, satisfaction with pacemaker, good family support, hospital and hospital staff performance, and role of religious beliefs. CONCLUSION: Planning to solve social problems, identifying and changing feelings of patients using pacemakers, reinforcing the resources of comfort especially family support seem to be necessary steps for improving quality of life and impact of using pacemaker. 

Radiation protection for pacemakers with radionuclide batteries

International Nuclear Information System (INIS)

Stieve, F.E.

1976-01-01

Radionuclide batteries ( 147 Pm, 238 Pu) in pacemakers bring risks for the patient and the environment, if the radioactive material cannot be secured for subsequent application or for safe end storage. This is why the expenditure connected with pacemakers is very high. So the application of such pacemakers is only indicated when the patient's expectation of life is presumably higher than 5-10 years, when there are no other diseases besides cardiac dysrhytmia, and when the securing of the radionuclide batteries is guaranteed. (orig.) [de

Analysis of a five year experience of permanent pacemaker ...

African Journals Online (AJOL)

Introduction: Permanent pacemaker implantation is available in Nigeria. There is however no national registry or framework for pacemaker data collection. A pacemaker database has been developed in our institution and the results are analyzed in this study. Methods: The study period was between January 2008 and ...

Uniform pacemaker and ICD information system in the Netherlands

NARCIS (Netherlands)

Cam, H; Wa, D; Callaos, N; Farsi, D; EshaghianWilner, M; Hanratty, T; Rishe, N

2003-01-01

The Central Pacemaker Patient Registry (CPPR) in the Netherlands (founded in 1977) collects information of pacemaker patients from all 110 Dutch hospitals. It contains data of over 98.000 patients, 118.500 pacemakers, 1.950 ICD's and 131.000 leads. Initially data was entered manually. As local

Neck Pain One Week after Pacemaker Generator Replacement.

Science.gov (United States)

Graham, Ross F; Wightman, John M

2015-07-01

The incidence of cardiac pacemaker implantation has risen markedly in the past three decades, making awareness of possible postprocedural complications critical to the emergency physician. This case is the first documented instance of internal jugular (IJ) deep vein thrombosis (DVT) from an uncomplicated pacemaker generator replacement. A patient presented to an Emergency Department with a 2-day history of mild left temporal headache migrating to his left neck. The patient did not volunteer this information, but review of systems revealed a temporary transvenous pacemaker inserted through the right IJ vein 1 week previously during a routine exchange of a left-sided cardiac pacemaker generator. Manipulation of the existing pacemaker wires entering the left subclavian vein was minimal. Computed tomographic angiography of the neck demonstrated near-complete thrombotic occlusion of the entire length of his left IJ vein. This required hospital admission for observation and treatment with anticoagulation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: DVT, with thrombotic extension into adjacent vessels anywhere along the course of pacemaker wires, should be considered by the emergency provider in the evaluation of head, neck, or upper extremity symptoms after recent or remote implantation or manipulation of a transvenous cardiac pacemaker, including generator replacement. Failure to identify and treat appropriately could result in significant morbidity and mortality from airway edema, septic thrombophlebitis, superior vena cava syndrome, superior sagittal sinus thrombosis, or pulmonary embolism. Published by Elsevier Inc.

Aggregatibacter aphrophilus pacemaker endocarditis: a case report.

Science.gov (United States)

Patel, Sahil R; Patel, Nishi H; Borah, Amit; Saltzman, Heath

2014-12-08

Aggregatibacter bacteria are a rare cause of endocarditis in adults. They are part of a group of organisms known as HACEK--Haemophilus, Aggregatibacter, Cardiobacter, Eikenella, and Kingella. Among these organisms, several Haemophilus species have been reclassified under the genus Aggregatibacter. Very few cases of Aggregatibacter endocarditis in patients with pacemaker devices have been reported. We present here what we believe to be the first case of Aggregatibacter aphrophilus pacemaker endocarditis. A 62-year-old African American male with a medical history significant for dual-chamber pacemaker placement in 1996 for complete heart block with subsequent lead manipulation in 2007, presented to his primary care doctor with fever, chills, night sweats, fatigue, and ten-pound weight loss over a four-month period. Physical examination revealed a new murmur and jugular venous distension which prompted initiation of antibiotics for suspicion of endocarditis. Both sets of initial blood cultures were positive for A. aphrophilus. Transesophageal echocardiogram revealed vegetations on the tricuspid valve and the right ventricular pacemaker lead (Figure 1). This case highlights the importance of identifying rare causes of endocarditis and recognizing that treatment may not differ from the standard treatment for typical presentations. The patient received intravenous ceftriaxone for his endocarditis for a total of six weeks. Upon device removal, temporary jugular venous pacing wires were placed. After two weeks of antibiotic treatment and no clinical deterioration, a new permanent pacemaker was placed and the patient was discharged home. This is the first case of A. aphrophilus endocarditis in a patient with a permanent pacemaker. Our patient had no obvious risk factors other than poor dentition and a history of repeated pacemaker lead manipulation. This suggests that valvulopathies secondary to repeated lead manipulation can be clinically significant factors in morbidity

Bipolar soft connected, bipolar soft disconnected and bipolar soft compact spaces

Directory of Open Access Journals (Sweden)

Muhammad Shabir

2017-06-01

Full Text Available Bipolar soft topological spaces are mathematical expressions to estimate interpretation of data frameworks. Bipolar soft theory considers the core features of data granules. Bipolarity is important to distinguish between positive information which is guaranteed to be possible and negative information which is forbidden or surely false. Connectedness and compactness are the most important fundamental topological properties. These properties highlight the main features of topological spaces and distinguish one topology from another. Taking this into account, we explore the bipolar soft connectedness, bipolar soft disconnectedness and bipolar soft compactness properties for bipolar soft topological spaces. Moreover, we introduce the notion of bipolar soft disjoint sets, bipolar soft separation, and bipolar soft hereditary property and study on bipolar soft connected and disconnected spaces. By giving the detailed picture of bipolar soft connected and disconnected spaces we investigate bipolar soft compact spaces and derive some results related to this concept.

Successful pacing using a batteryless sunlight-powered pacemaker.

Science.gov (United States)

Haeberlin, Andreas; Zurbuchen, Adrian; Schaerer, Jakob; Wagner, Joerg; Walpen, Sébastien; Huber, Christoph; Haeberlin, Heinrich; Fuhrer, Juerg; Vogel, Rolf

2014-10-01

Today's cardiac pacemakers are powered by batteries with limited energy capacity. As the battery's lifetime ends, the pacemaker needs to be replaced. This surgical re-intervention is costly and bears the risk of complications. Thus, a pacemaker without primary batteries is desirable. The goal of this study was to test whether transcutaneous solar light could power a pacemaker. We used a three-step approach to investigate the feasibility of sunlight-powered cardiac pacing. First, the harvestable power was estimated. Theoretically, a subcutaneously implanted 1 cm(2) solar module may harvest ∼2500 µW from sunlight (3 mm implantation depth). Secondly, ex vivo measurements were performed with solar cells placed under pig skin flaps exposed to a solar simulator and real sunlight. Ex vivo measurements under real sunlight resulted in a median output power of 4941 µW/cm(2) [interquartile range (IQR) 3767-5598 µW/cm(2), median skin flap thickness 3.0 mm (IQR 2.7-3.3 mm)]. The output power strongly depended on implantation depth (ρSpearman = -0.86, P pacemaker powered by a 3.24 cm(2) solar module was implanted in vivo in a pig to measure output power and to pace. In vivo measurements showed a median output power of >3500 µW/cm(2) (skin flap thickness 2.8-3.84 mm). Successful batteryless VVI pacing using a subcutaneously implanted solar module was performed. Based on our results, we estimate that a few minutes of direct sunlight (irradiating an implanted solar module) allow powering a pacemaker for 24 h using a suitable energy storage. Thus, powering a pacemaker by sunlight is feasible and may be an alternative energy supply for tomorrow's pacemakers. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Pacemaker implantation after catheter ablation for atrial fibrillation.

Science.gov (United States)

Deshmukh, Abhishek J; Yao, Xiaoxi; Schilz, Stephanie; Van Houten, Holly; Sangaralingham, Lindsey R; Asirvatham, Samuel J; Friedman, Paul A; Packer, Douglas L; Noseworthy, Peter A

2016-01-01

Sinus node dysfunction requiring pacemaker implantation is commonly associated with atrial fibrillation (AF), but may not be clinically apparent until restoration of sinus rhythm with ablation or cardioversion. We sought to determine frequency, time course, and predictors for pacemaker implantation after catheter ablation, and to compare the overall rates to a matched cardioversion cohort. We conducted a retrospective analysis using a large US commercial insurance database and identified 12,158 AF patients who underwent catheter ablation between January 1, 2005 and December 31, 2012. Over an average of 2.4 years of follow-up, 5.6 % of the patients underwent pacemaker implantation. Using the Cox proportional hazards models, we found that risk of risks of pacemaker implantation was associated with older age (50-64 and ≥65 versus pacemaker implantation between ablation patients and propensity score (PS)-matched cardioversion groups (3.5 versus. 4.1 % at 1 year and 8.8 versus 8.3 % at 5 years). Overall, pacemaker implantation occurs in about 1/28 patients within 1 year of catheter ablation. The overall implantation rate decreased between 2005 and 2012. Furthermore, the risk after ablation is similar to cardioversion, suggesting that patients require pacing due to a common underlying electrophysiologic substrate, rather than the ablation itself.

Validation of the Netherlands pacemaker patient registry

NARCIS (Netherlands)

Dijk, WA; Kingma, T; Hooijschuur, CAM; Dassen, WRM; Hoorntje, JCA; van Gelder, LM

1997-01-01

This paper deals with the validation of the information stored in the Netherlands central pacemaker patient database. At this moment the registry database contains information on more than 70500 patients, 85000 pacemakers and 90000 leads. The validation procedures consisted of an internal

On the Evolution of the Cardiac Pacemaker

NARCIS (Netherlands)

Burkhard, Silja; van Eif, Vincent; Garric, Laurence; Christoffels, Vincent M.; Bakkers, Jeroen

2017-01-01

The rhythmic contraction of the heart is initiated and controlled by an intrinsic pacemaker system. Cardiac contractions commence at very early embryonic stages and coordination remains crucial for survival. The underlying molecular mechanisms of pacemaker cell development and function are still not

Feasibility of pacemaker therapy after dynamic cardiomyoplasty

NARCIS (Netherlands)

Van den Berg, MP; Nagelkerke, D; Brouwer, RMHJ; Mulder, H; De Boer, H; Crijns, HJGM

1999-01-01

A 54-year-old man presented with total atrioventricular (AV) block 3 months after dynamic cardiomyoplasty was performed because of heart failure due to idiopathic dilated cardiomyopathy. Though the cardiomyostimulator acted as a back-up pacemaker, a DDDR pacemaker was implanted to optimize

Connectivity of Pacemaker Neurons in the Neonatal Rat Superficial Dorsal Horn

Science.gov (United States)

Ford, Neil C.; Arbabi, Shahriar; Baccei, Mark L.

2014-01-01

Pacemaker neurons with an intrinsic ability to generate rhythmic burst-firing have been characterized in lamina I of the neonatal spinal cord, where they are innervated by high-threshold sensory afferents. However, little is known about the output of these pacemakers, as the neuronal populations which are targeted by pacemaker axons have yet to be identified. The present study combines patch clamp recordings in the intact neonatal rat spinal cord with tract-tracing to demonstrate that lamina I pacemaker neurons contact multiple spinal motor pathways during early life. Retrograde labeling of premotor interneurons with the trans-synaptic virus PRV-152 revealed the presence of burst-firing in PRV-infected lamina I neurons, thereby confirming that pacemakers are synaptically coupled to motor networks in the spinal ventral horn. Notably, two classes of pacemakers could be distinguished in lamina I based on cell size and the pattern of their axonal projections. While small pacemaker neurons possessed ramified axons which contacted ipsilateral motor circuits, large pacemaker neurons had unbranched axons which crossed the midline and ascended rostrally in the contralateral white matter. Recordings from identified spino-parabrachial and spino-PAG neurons indicated the presence of pacemaker activity within neonatal lamina I projection neurons. Overall, these results show that lamina I pacemakers are positioned to regulate both the level of activity in developing motor circuits as well as the ascending flow of nociceptive information to the brain, thus highlighting a potential role for pacemaker activity in the maturation of pain and sensorimotor networks in the CNS. PMID:25380417

The thermodynamics of bipolarity: a bifurcation model of bipolar illness and bipolar character and its psychotherapeutic applications.

Science.gov (United States)

Sabelli, H C; Carlson-Sabelli, L; Javaid, J I

1990-11-01

Two models dominate current formulations of bipolar illness: the homeostatic model implicit in Freud's psychodynamics and most neuroamine deficit/excess theories; and the oscillatory model of exaggerated biological rhythms. The homeostatic model is based on the closed systems approach of classic thermodynamics, while the oscillatory model requires the open systems approach of modern thermodynamics. Here we present a thermodynamic model of bipolarity that includes both homeostatic and oscillatory features and adds the most important feature of open systems thermodynamics: the creation of novel structures in bifurcation processes. According to the proposed model, bipolarity is the result of exaggerated biological energy that augments homeostatic, oscillatory and creative psychological processes. Only low-energy closed systems tend to rest ("point attractor") and entropic disorder. Open processes containing and exchanging energy fluctuate between opposite states ("periodic attractors"); they are characteristic of most physiological rhythms and are exaggerated in bipolar subjects. At higher energies, their strong fluctuations destroy pre-existing patterns and structures, produce turbulence ("chaotic attractors"), which sudden switches between opposite states, and create new and more complex structures. Likewise, high-energy bipolars develop high spontaneity, great fluctuations between opposite moods, internal and interpersonal chaos, and enhanced creativity (personal, artistic, professional) as well as psychopathology (personality deviations, psychotic delusions). Offered here is a theoretical explanation of the dual--creative and destructive--nature of bipolarity in terms of the new enantiodromic concept of entropy generalized by process theory. Clinically, this article offers an integrative model of bipolarity that accounts for many clinical features and contributes to a definition of the bipolar personality.

Development of the cardiac pacemaker

Science.gov (United States)

Liang, Xingqun; Evans, Sylvia M.

2017-01-01

The sinoatrial node (SAN) is the dominant pacemaker of the heart. Abnormalities in SAN formation and function can cause sinus arrhythmia, including sick sinus syndrome and sudden death. A better understanding of genes and signaling pathways that regulate SAN development and function is essential to develop more effective treatment to sinus arrhythmia, including biological pacemakers. In this review, we briefly summarize the key processes of SAN morphogenesis during development, and focus on the transcriptional network that drives SAN development. PMID:27770149

Fifty years of pacemaker advancements.

Science.gov (United States)

Steinhaus, David

2008-12-01

A 1957 power blackout in Minnesota prompted C. Walton Lillehei, MD, a pioneer in open heart surgery, to ask Earl Bakken, the co-founder of Medtronic, Inc., to create a battery-operated pacemaker for pediatric patients. That conversation led to the development of the first external battery-operated pacemaker. That first bulky device is far removed from the tiny implantable computers available to heart patients today. Now, the size of two silver dollars stacked on top of one another, a pacemaker is prescribed for a person whose heart beats too slowly or pauses irregularly. Slightly larger devices have more recently evolved from pacing and regulating the heartbeat to being able to provide therapeutic high voltage shocks when needed to stop runaway fast heart rates, recording heart activity, and other physiologic functions, even resynchronizing the heart's chambers-all while providing information on the patient's condition and device performance to the doctor remotely or in the office.

Influence of digital and analogue cellular telephones on implanted pacemakers.

Science.gov (United States)

Altamura, G; Toscano, S; Gentilucci, G; Ammirati, F; Castro, A; Pandozi, C; Santini, M

1997-10-01

The aim of this study was to find out whether digital and analogue cellular 'phones affect patients with pacemakers. The study comprised continuous ECG monitoring of 200 pacemaker patients. During the monitoring certain conditions caused by interference created by the telephone were looked for: temporary or prolonged pacemaker inhibition; a shift to asynchronous mode caused by electromagnetic interference; an increase in ventricular pacing in dual chamber pacemakers, up to the programmed upper rate. The Global System for Mobile Communications system interfered with pacing 97 times in 43 patients (21.5%). During tests on Total Access of Communication System telephones, there were 60 cases of pacing interference in 35 patients (17.5%). There were 131 interference episodes during ringing vs 26 during the on/off phase; (P 4 s) was seen at the pacemaker 'base' sensing value in six patients using the Global system but in only one patient using Total Access. Cellular 'phones may be dangerous for pacemaker patients. However, they can be used safely if patients do not carry the 'phone close to the pacemaker, which is the only place where high risk interference has been observed.

Effect of telecobalt irradiation on the function of implantable pacemaker

International Nuclear Information System (INIS)

Toyoda, Michiaki

1986-01-01

In patients implanted with a pacemaker, radiotherapy may be chosen as the treatment when malignant tumor is complicated. Therefore, on the assumption that the pacemaker apparatus is exposed to X-ray, 21 lithium cells used for CMOS or TTL circuit were collected before expiration date and irradiated with 60 Co. The pacemaker used were 10 apparatuses of unprogrammed model VVI, 9 apparatuses of programmed model VVI and 2 apparatuses programmed model DVI. Irradiation was done up to 1,000 rads in dividing doses or at 1,000 rads as a single dose. Observations were made for effects on intervals, amplitude and wave shape of stimula to pacemaker, power, sensitivity, refractory phase, and program functions. In conclusion, it was found that pacemaker is sure to be affected considerably for various functions, although no functional arrest occurs, under irradiation up to 1,000 rads of 60 Co in dividing dose. When irradiation at 1,000 rads was given as a single dose, dysfunctions of pacemaker developed in some cases indicating that direct irradiation at high doses is contraindicated for pacemakers using much of LSI-CMOS. (author)

Pacemaker lead fracture associated with weightlifting: a report of two cases.

Science.gov (United States)

Deering, J A; Pederson, D N

1993-12-01

Two cases of pacemaker lead fracture associated with weight-lifting are presented. This is a rare association which has only recently been described in the literature. In both cases, the pacemaker lead was fractured between the clavicle and the first rib, suggesting crush injury. The chest X-ray, pacemaker telemetry with measurement of lead impedance, and pacemaker reprogramming were all helpful in management.

Conduction disturbances after TAVR: Electrophysiological studies and pacemaker dependency.

Science.gov (United States)

Makki, Nader; Dollery, Jenn; Jones, Danielle; Crestanello, Juan; Lilly, Scott

Permanent pacemaker (PPM) placement occurs in 5-20% of patients after transcatheter aortic valve replacement (TAVR). Although predictors of pacemaker implantation have been established, features that predispose patients to pacemaker utilization on follow up have not been widely reported. We performed a retrospective review of patients undergoing commercial TAVR between 2011 and 2016. We collated patients that underwent in-hospital PPM implantation and had a follow up of at least 3months. Data abstraction was performed for electrophysiological studies (EPS), pacemaker indication, timing, and device interrogation for pacemaker dependency on follow up. A total of 24 patients received in-hospital PPM post-TAVR (14% of total cohort), and mean follow up was 22months. Indications for PPM included resting complete heart block (CHB; 15/24, 63%), left bundle branch block and abnormal electrophysiological study (EPS; 7/24, 29%), alternating bundle branch block (1/24, 4%) and tachy-brady syndrome (1/24, 4%). Pacemaker dependency (underlying ventricular asystole, complete heart block, or >50% pacing) occurred in 8/24 patients (33%) during follow-up, 7 of whom had resting CHB, and one with CHB invoked during EPS. Pacemaker dependency after TAVR is common among those that exhibited CHB, but not among those with a prolonged HV delay during EPS. Although preliminary, these observations are relevant to management of rhythm disturbances after TAVR, and may inform the practice of EPS-based PPM implantation. Copyright © 2017 Elsevier Inc. All rights reserved.

Analysis of Cumulative Dose to Implanted Pacemaker According to Various IMRT Delivery Methods: Optimal Dose Delivery Versus Dose Reduction Strategy

Energy Technology Data Exchange (ETDEWEB)

Lee, Jeong Woo; Hong, Se Mie [Dept. of Radiation Oncology, Konkuk University Medical Center, Seoul (Korea, Republic of)

2011-11-15

Cancer patients with implanted cardiac pacemaker occasionally require radiotherapy. Pacemaker may be damaged or malfunction during radiotherapy due to ionizing radiation or electromagnetic interference. Although radiotherapy should be planned to keep the dose to pacemaker as low as possible not to malfunction ideally, current radiation treatment planning (RTP) system does not accurately calculate deposited dose to adjacent field border or area beyond irradiated fields. In terms of beam delivery techniques using multiple intensity modulated fields, dosimetric effect of scattered radiation in high energy photon beams is required to be detailed analyzed based on measurement data. The aim of this study is to evaluate dose discrepancies of pacemaker in a RTP system as compared to measured doses. We also designed dose reduction strategy limited value of 2 Gy for radiation treatment patients with cardiac implanted pacemaker. Total accumulated dose of 145 cGy based on in-vivo dosimetry was satisfied with the recommendation criteria to prevent malfunction of pacemaker in SS technique. However, the 2 mm lead shielder enabled the scattered doses to reduce up to 60% and 40% in the patient and the phantom, respectively. The SS technique with the lead shielding could reduce the accumulated scattered doses less than 100 cGy. Calculated and measured doses were not greatly affected by the beam delivery techniques. In-vivo and measured doses on pacemaker position showed critical dose discrepancies reaching up to 4 times as compared to planned doses in RTP. The current SS technique could deliver lower scattered doses than recommendation criteria, but use of 2 mm lead shielder contributed to reduce scattered doses by 60%. The tertiary lead shielder can be useful to prevent malfunction or electrical damage of implanted pacemakers during radiotherapy. It is required to estimate more accurate scattered doses of the patient or medical device in RTP to design proper dose reduction strategy.

Analysis of Cumulative Dose to Implanted Pacemaker According to Various IMRT Delivery Methods: Optimal Dose Delivery Versus Dose Reduction Strategy

International Nuclear Information System (INIS)

Lee, Jeong Woo; Hong, Se Mie

2011-01-01

Cancer patients with implanted cardiac pacemaker occasionally require radiotherapy. Pacemaker may be damaged or malfunction during radiotherapy due to ionizing radiation or electromagnetic interference. Although radiotherapy should be planned to keep the dose to pacemaker as low as possible not to malfunction ideally, current radiation treatment planning (RTP) system does not accurately calculate deposited dose to adjacent field border or area beyond irradiated fields. In terms of beam delivery techniques using multiple intensity modulated fields, dosimetric effect of scattered radiation in high energy photon beams is required to be detailed analyzed based on measurement data. The aim of this study is to evaluate dose discrepancies of pacemaker in a RTP system as compared to measured doses. We also designed dose reduction strategy limited value of 2 Gy for radiation treatment patients with cardiac implanted pacemaker. Total accumulated dose of 145 cGy based on in-vivo dosimetry was satisfied with the recommendation criteria to prevent malfunction of pacemaker in SS technique. However, the 2 mm lead shielder enabled the scattered doses to reduce up to 60% and 40% in the patient and the phantom, respectively. The SS technique with the lead shielding could reduce the accumulated scattered doses less than 100 cGy. Calculated and measured doses were not greatly affected by the beam delivery techniques. In-vivo and measured doses on pacemaker position showed critical dose discrepancies reaching up to 4 times as compared to planned doses in RTP. The current SS technique could deliver lower scattered doses than recommendation criteria, but use of 2 mm lead shielder contributed to reduce scattered doses by 60%. The tertiary lead shielder can be useful to prevent malfunction or electrical damage of implanted pacemakers during radiotherapy. It is required to estimate more accurate scattered doses of the patient or medical device in RTP to design proper dose reduction strategy.

An electromagnetic compatibility study of cardiac pacemaker to low frequency interferences

International Nuclear Information System (INIS)

Andretzko, J.P.; Hedjiedj, A.; Babouri, A.; Guendouz, L.; Nadi, M.

2006-01-01

This paper presents an experimental study of the behaviour of cardiac pacemaker submitted to low frequency electromagnetic interferences. The method used in this study is progressive. It consists in starting from the target (the cardiac pacemaker), identifying and quantifying the disturbances (the source), and then introducing secondary influencing parameters in stepwise fashion. The general problematic consists in checking this immunity in relation with led disruptions and in relation with beaming disruptions. The experimental approach suggests two kind of tests corresponding to the two studied coupling modes. The first one corresponds to a direct applying of the disruptive signal between the pacemaker terminals. The objective of this phase is to determine the characteristics of the signal (amplitude and frequency) which are detected by the pacemaker and which generate modifications of its operation. In the second phase the pacemaker is subjected to a variable low frequency magnetic field. This last interacts with the pacemaker by inductive coupling through the loop formed by the pacemaker and its leads and the surrounding medium. This interaction results in an induced electromotive force between the terminals of the pacemaker which can potentially disturb the operation of this last. The objective of this phase is to characterize the signal (magnetic field) likely to generate these disturbances. Tests are carried out on six single chamber pacemaker and five dual chamber pacemaker. The interfering signal frequencies are 50 Hz, 60 Hz, 10 khz and 25 khz. Tracking and programming of the pacemaker housing is achieved with the telemetry system. In this study, the devices have all been configured in inhibited stimulation (S.S.I. or V.V.I. mode according to the international codification), this configuration being the most widespread. The housing stimulates the basic frequency in the absence o f intrinsic activity, the stimulation can be inhibited in each chamber by a

An electromagnetic compatibility study of cardiac pacemaker to low frequency interferences

Energy Technology Data Exchange (ETDEWEB)

Andretzko, J.P.; Hedjiedj, A.; Babouri, A.; Guendouz, L.; Nadi, M. [Nancy-1 Univ. Henri Poincare, Lab. d' Instrumentation Electronique de Nancy, Faculte des Sciences, 54 - Vandoeuvre les Nancy (France)

2006-07-01

This paper presents an experimental study of the behaviour of cardiac pacemaker submitted to low frequency electromagnetic interferences. The method used in this study is progressive. It consists in starting from the target (the cardiac pacemaker), identifying and quantifying the disturbances (the source), and then introducing secondary influencing parameters in stepwise fashion. The general problematic consists in checking this immunity in relation with led disruptions and in relation with beaming disruptions. The experimental approach suggests two kind of tests corresponding to the two studied coupling modes. The first one corresponds to a direct applying of the disruptive signal between the pacemaker terminals. The objective of this phase is to determine the characteristics of the signal (amplitude and frequency) which are detected by the pacemaker and which generate modifications of its operation. In the second phase the pacemaker is subjected to a variable low frequency magnetic field. This last interacts with the pacemaker by inductive coupling through the loop formed by the pacemaker and its leads and the surrounding medium. This interaction results in an induced electromotive force between the terminals of the pacemaker which can potentially disturb the operation of this last. The objective of this phase is to characterize the signal (magnetic field) likely to generate these disturbances. Tests are carried out on six single chamber pacemaker and five dual chamber pacemaker. The interfering signal frequencies are 50 Hz, 60 Hz, 10 khz and 25 khz. Tracking and programming of the pacemaker housing is achieved with the telemetry system. In this study, the devices have all been configured in inhibited stimulation (S.S.I. or V.V.I. mode according to the international codification), this configuration being the most widespread. The housing stimulates the basic frequency in the absence o f intrinsic activity, the stimulation can be inhibited in each chamber by a

Contribution of small conductance K+ channels to sinoatrial node pacemaker activity: insights from atrial-specific Na+ /Ca2+ exchange knockout mice.

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Torrente, Angelo G; Zhang, Rui; Wang, Heidi; Zaini, Audrey; Kim, Brian; Yue, Xin; Philipson, Kenneth D; Goldhaber, Joshua I

2017-06-15

Repolarizing currents through K + channels are essential for proper sinoatrial node (SAN) pacemaking, but the influence of intracellular Ca 2+ on repolarization in the SAN is uncertain. We identified all three isoforms of Ca 2+ -activated small conductance K + (SK) channels in the murine SAN. SK channel blockade slows repolarization and subsequent depolarization of SAN cells. In the atrial-specific Na + /Ca 2+ exchanger (NCX) knockout mouse, cellular Ca 2+ accumulation during spontaneous SAN pacemaker activity produces intermittent hyperactivation of SK channels, leading to arrhythmic pauses alternating with bursts of pacing. These findings suggest that Ca 2+ -sensitive SK channels can translate changes in cellular Ca 2+ into a repolarizing current capable of modulating pacemaking. SK channels are a potential pharmacological target for modulating SAN rate or treating SAN dysfunction, particularly under conditions characterized by abnormal increases in diastolic Ca 2+ . Small conductance K + (SK) channels have been implicated as modulators of spontaneous depolarization and electrical conduction that may be involved in cardiac arrhythmia. However, neither their presence nor their contribution to sinoatrial node (SAN) pacemaker activity has been investigated. Using quantitative PCR (q-PCR), immunostaining and patch clamp recordings of membrane current and voltage, we identified all three SK isoforms (SK1, SK2 and SK3) in mouse SAN. Inhibition of SK channels with the specific blocker apamin prolonged action potentials (APs) in isolated SAN cells. Apamin also slowed diastolic depolarization and reduced pacemaker rate in isolated SAN cells and intact tissue. We investigated whether the Ca 2+ -sensitive nature of SK channels could explain arrhythmic SAN pacemaker activity in the atrial-specific Na + /Ca 2+ exchange (NCX) knockout (KO) mouse, a model of cellular Ca 2+ overload. SAN cells isolated from the NCX KO exhibited higher SK current than wildtype (WT) and apamin

Low pacemaker incidence with continuous-sutured valves: a retrospective analysis.

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Niclauss, Lars; Delay, Dominique; Pfister, Raymond; Colombier, Sebastien; Kirsch, Matthias; Prêtre, René

2017-06-01

Background Permanent pacemaker implantation after surgical aortic valve replacement depends on patient selection and risk factors for conduction disorders. We aimed to identify risk criteria and obtain a selected group comparable to patients assigned to transcatheter aortic valve implantation. Methods Isolated sutured aortic valve replacements in 994 patients treated from 2007 to 2015 were reviewed. Demographics, hospital stay, preexisting conduction disorders, surgical technique, and etiology in patients with and without permanent pacemaker implantation were compared. Reported outcomes after transcatheter aortic valve implantation were compared with those of a subgroup including only degenerative valve disease and first redo. Results The incidence of permanent pacemaker implantation was 2.9%. Longer hospital stay ( p = 0.01), preexisting rhythm disorders ( p pacemaker implantation. Although prostheses were sutured with continuous monofilament in the majority of cases (86%), interrupted pledgetted sutures were used more often in the pacemaker group ( p = 0.002). In the subgroup analysis, the incidence of permanent pacemaker implantation was 2%; preexisting rhythm disorders and the suture technique were still major risk factors. Conclusion Permanent pacemaker implantation depends on etiology, preexisting rhythm disorders, and suture technique, and the 2% incidence compares favorably with the reported 5- to 10-fold higher incidence after transcatheter aortic valve implantation. Cost analysis should take this into account. Often dismissed as minor complication, permanent pacemaker implantation increases the risks of endocarditis, impaired myocardial recovery, and higher mortality if associated with prosthesis regurgitation.

Case of pacemaker pocket infection caused by Finegoldia magna.

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Hosseini Dehkordi, Seyed Hamed; Osorio, Georgina

2017-10-01

Finegoldia magna (formerly called Peptostreptococcus magnus) is a Gram-positive anaerobic coccus which is increasingly recognized as an opportunistic pathogen. We present a case of F. magna associated non-valvular cardiovascular device-related infection in an 83 year-old male who received a permanent pacemaker for sick sinus syndrome seven weeks prior to his presentation. Five weeks after the implantation, the pacemaker and leads were explanted because of clinical evidence of pacemaker pocket infection. He was initially treated with sulfamethoxazole-trimethoprim based on the Gram stain results from the removed pacemaker. However, two weeks later, he was readmitted with sepsis and was successfully treated with ampicillin-sulbactam. Culture results from the pacemaker and pocket as well as blood cultures grew F. magna. Clinicians should be aware of the possibility of F. magna infection when initial gram stain results show "gram positive cocci". Copyright © 2017 Elsevier Ltd. All rights reserved.

Pacemaker lead erosion simulating "Loch Ness Monster": conservative management.

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Garg, Naveen; Moorthy, Nagaraja

2012-12-01

The majority of pacemaker pocket or lead erosions are due to either mechanical erosion by the bulky pulse generator or secondary to pacemaker pocket infection. We describe an unusual case of delayed pacemaker lead erosion causing extrusion of a portion of the pacing lead, with separate entry and exit points, with the gap filled with new skin formation, simulating the "Loch Ness Monster", which was successfully managed conservatively by surgical reinsertion.

A devices' game of thrones: cardiac resynchronization therapy vs. pacemaker.

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Moura-Ferreira, Sara; Gonçalves, Helena; Oliveira, Marco; Primo, João; Fonseca, Paulo; Ribeiro, José; Santos, Elisabeth; Pelicano, Nuno; Martins, Dinis; Gama, Vasco

2017-12-01

Oversensing can interfere with biventricular pacing. Cardiac Resynchronization Therapy (CRT) output inhibition due to automatic brady mode change from a sensing to a pacing mode of a previously implanted pacemaker as it reached battery capacity depleted indicator has not been previously published in the medical literature. We report the first case of CRT output inhibition in a pacemaker dependent patient due to electrical stimuli from a previously right-sided implanted pacemaker, after unaware reversion of OVO mode (O = no chambers paced; V = ventricular sensing; O = no response to sensing) to backup VVI (V = ventricular pacing; V = ventricular sensing; I = inhibitory response to sensing) when it reached the elective replacement interval. This paper emphasizes the importance of knowing the distinct pacemaker brady mode behaviours after battery capacity depleted indicator has been reached, according to the pacemakers' manufacturer, including the possibility of automatic brady mode change from sensing to pacing mode. It also highlights the potential for severe bradycardia or asystole of this automatic brady mode change from a previously implanted pacemaker in pacemaker dependent patients submitted to CRT upgrade. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Sub-bandgap photonic base current method for characterization of interface states at heterointerfaces in heterojunction bipolar transistors

International Nuclear Information System (INIS)

Shin, H. T.; Kim, K. H.; Kim, K. S.

2004-01-01

In this paper, we propose a novel photonic base current analysis method to characterize the interface states in heterojunction bipolar transistors (HBTs) by using the photonic I-V characteristics under sub-bandgap photonic excitation. For the photonic current-voltage characterization of HBTs, an optical source with a photon energy less than the bandgap energy of Al 0.3 Ga 0.7 As and GaAs (E ph = 0.95 eV g,AlGaAs = 1.79 eV, E g,GaAs = 1.45 eV) is employed for the characterization of the interface states distributed in the photo-responsive energy band (E C - 0.95 ≤ E it ≤ E C ) in emitter-base heterojunction at HBTs. The proposed novel method, which is applied to bipolar junction transistors for the first time, is simple, and an accurate analysis of interface traps in HBTs is possible. By using the photonic base-current and the dark-base-current, we qualitatively analyze the interface trap at the Al 0.3 Ga 0.7 As/GaAs heterojunction interface in HBTs.

Troponin T elevation after permanent pacemaker implantation.

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Chen, Xueying; Yu, Ziqing; Bai, Jin; Hu, Shulan; Wang, Wei; Qin, Shengmei; Wang, Jingfeng; Sun, Zhe; Su, Yangang; Ge, Junbo

2017-08-01

The objective of the study is to study the incidence, significance, and factors associated with cardiac troponin T (CTNT) elevation after pacemaker implantation. Three hundred seventy-four patients (104 single-chamber pacemakers or ICD, 243 dual-chamber pacemakers, and 27 cardiac resynchronization therapy/cardiac resynchronization therapy defibrillator) who had normal levels of CTNT at baseline and underwent implantation of a permanent pacemaker system were included in this study. Serum levels of CTNT were measured at baseline, 6 and 24 h after the implantation procedure. The median of CTNT levels increased from 0.012 ng/mL at baseline to 0.032 and 0.019 ng/mL at 6 and 24 h after the procedure, respectively (all p 0.09 ng/mL). After 1-year follow-up, the incidence of complications including dislodgement of the lead, pocket infection, pneumothorax, hemothorax, and vein thrombus and cardiac outcomes including hospitalization of heart failure, coronary artery disease, arrhythmia, and cardiovascular mortality was not significantly different between the normal and elevated CTNT groups at 6 h after the procedure. By logistic regression analysis, gender, N-terminal pro-B type natriuretic peptide (NT-pro-BNP) at baseline, left ventricular ejection fractions (LVEF), estimated glomerular filtration rate (eGFR), and fluoroscopy time were independently associated with CTNT elevation after adjusted for age, pacemaker types, right ventricle lead location (RVA or RVOT), heart function, and left ventricular end systolic dimension. Pacemaker implantation was found to be accompanied with CTNT elevation in 55.6% of the patients at 6 h after the procedure, and its kinetics were fast, which might not be related to the complications and adverse cardiac outcomes within 1 year of follow-up. Moreover, gender, NT-pro-BNP at baseline, LVEF, eGFR, and fluoroscopy time were found to be independent predictors of CTNT elevation.

Abordagens psicoterápicas no transtorno bipolar Psychoterapeutic approach in bipolar disorder

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Paulo Knapp

2005-01-01

Full Text Available Embora o tratamento farmacológico seja essencial para o tratamento do transtorno bipolar, apenas 40% de todos os pacientes que aderem às medicações permanecem assintomáticos durante o período de seguimento, o que tem levado ao desenvolvimento de intervenções psicoterápicas associadas. O objetivo deste artigo é examinar as evidências atuais da eficácia de intervenções psicoterápicas no tratamento do transtorno bipolar. Foi realizada uma pesquisa bibliográfica por meio do MedLine, PsychoINFO, Lilacs e Cochrane Data Bank, até o ano de 2004, em que foram procurados artigos originais e revisões sobre as abordagens psicoterápicas utilizadas no tratamento do transtorno bipolar. Há várias abordagens que podem se mostrar úteis no tratamento do transtorno bipolar. A psicoeducação e a terapia cognitivo-comportamental apresentam as evidências mais consistentes e são as técnicas mais amplamente estudadas. As intervenções envolvendo familiares e a terapia interpessoal e de ritmo social se mostram tratamentos eficazes em determinadas situações. Há alguns estudos empregando a terapia psicodinâmica no transtorno bipolar, mas são estudos com limitações metodológicas. Apesar de haver evidências demonstrando a eficácia de determinadas abordagens psicoterápicas no transtorno bipolar, ainda é necessária a realização de estudos posteriores que comprovem tais dados e que desenvolvam tratamentos baseados em modelos etiológicos e que identifiquem tratamentos específicos para as diferentes fases e tipos de transtorno bipolar.Although pharmacological treatment is essential for treating bipolar disorder, less than half of all medication compliant patients are non-symptomatic during follow-up, which has led to developments of adjunctive psychosocial interventions. This paper examines the current evidence for effectiveness of psychotherapeutic interventions in the treatment of bipolar disorder. Searches were undertaken through Med

Evaluating the pacemaker effect with the pump parameter of gated blood-pool imaging

International Nuclear Information System (INIS)

Cheng Muhua

1995-01-01

13 normal controls and 27 patients with ventricular pacemaker had undergone planar gated blood-pool imaging in different conditions. Result shows: (1) Pump parameters can successfully reflect therapeutic effect of pacemaker among them EMP is the most valuable parameter for evaluating the cardiac pumping effect. (2) After implantation of the ventricular pacemaker, the LVEF did not increase, but the CO and EMP was significantly increased. (3) Compared with right ventricular demand pacemaker, the rate-responsive ventricular pacemaker give better hemodynamic benefit at exercise condition. (4) Through restrained cardiac pacemaker the functional change was analyzed on or off pace, and monitoring the cardiac function itself after the pacemaker was implanted

Nuclear-powered pacemaker fuel cladding study

International Nuclear Information System (INIS)

Shoup, R.L.

1976-01-01

The composite of metals and alloys used in the fabrication of 238 Pu cardiac pacemaker fuel capsules resists the effects of high temperatures, high mechanical forces, and chemical corrosives and provides more than adequate protection to the fuel pellet even from deliberate attempts to dissolve the cladding in inorganic acids. This does not imply that opening a pacemaker fuel capsule by inorganic acids is impossible but that it would not be a wise choice

Does high-power computed tomography scanning equipment affect the operation of pacemakers?

International Nuclear Information System (INIS)

Yamaji, Satoshi; Imai, Shinobu; Saito, Fumio; Yagi, Hiroshi; Kushiro, Toshio; Uchiyama, Takahisa

2006-01-01

Computed tomography (CT) is widely used in clinical practice, but there has not been a detailed report of its effect on the functioning of pacemakers. During CT, ECGs were recorded in 11 patients with pacemakers and the electromagnetic field in the CT room was also measured. The effect of CT on a pacemaker was also investigated in a human body model with and without shielding by rubber or lead. Transient malfunctions of pacemakers during CT occurred in 6 of 11 patients. The model showed that malfunctioning of the pacemaker was induced by CT scanning and this was prevented by lead but not by rubber. The alternating electrical field was 150 V/m on the CT scanning line, which was lower than the level influencing pacemaker functions. The alternating magnetic field was 15μT on the CT scanning line, which was also lower than the level influencing pacemaker functions. Malfunctions of the pacemaker during CT may be caused by diagnostic radiant rays and although they are transient, the possibility of lethal arrhythmia cannot be ignored. (author)

Novel approach to epicardial pacemaker implantation in patients with limited venous access.

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Costa, Roberto; Scanavacca, Mauricio; da Silva, Kátia Regina; Martinelli Filho, Martino; Carrillo, Roger

2013-11-01

Limited venous access in certain patients increases the procedural risk and complexity of conventional transvenous pacemaker implantation. The purpose of this study was to determine a minimally invasive epicardial approach using pericardial reflections for dual-chamber pacemaker implantation in patients with limited venous access. Between June 2006 and November 2011, 15 patients underwent epicardial pacemaker implantation. Procedures were performed through a minimally invasive subxiphoid approach and pericardial window with subsequent fluoroscopy-assisted lead placement. Mean patient age was 46.4 ± 15.3 years (9 male [(60.0%], 6 female [40.0%]). The new surgical approach was used in patients determined to have limited venous access due to multiple abandoned leads in 5 (33.3%), venous occlusion in 3 (20.0%), intravascular retention of lead fragments from prior extraction in 3 (20.0%), tricuspid valve vegetation currently under treatment in 2 (13.3%), and unrepaired intracardiac defects in 2 (13.3%). All procedures were successful with no perioperative complications or early deaths. Mean operating time for isolated pacemaker implantation was 231.7 ± 33.5 minutes. Lead placement on the superior aspect of right atrium, through the transverse sinus, was possible in 12 patients. In the remaining 3 patients, the atrial lead was implanted on the left atrium through the oblique sinus, the postcaval recess, or the left pulmonary vein recess. None of the patients displayed pacing or sensing dysfunction, and all parameters remained stable throughout the follow-up period of 36.8 ± 25.1 months. Epicardial pacemaker implantation through pericardial reflections is an effective alternative therapy for those patients requiring physiologic pacing in whom venous access is limited. © 2013 Heart Rhythm Society. All rights reserved.

Treatment of vasovagal syncope: pacemaker or crossing legs?

NARCIS (Netherlands)

van Dijk, N.; Harms, M. P.; Linzer, M.; Wieling, W.

2000-01-01

A 50-year-old male patient continued to experience syncope after implantation of a pacemaker. During cardiovascular examination, the patient showed a typical vasovagal response, with normal pacemaker function. Leg crossing, which prohibits the pooling of blood in the legs and abdomen, at the onset

Runaway pacemaker: a forgotten phenomenon?

Science.gov (United States)

Ortega, Daniel F; Sammartino, M Victoria; Pellegrino, Graciela M M; Barja, Luis D; Albina, Gaston; Segura, Eliseo V; Balado, Roberto; Laiño, Ruben; Giniger, Alberto G

2005-11-01

Runaway is an uncommon pacemaker dysfunction, characterized by fast and erratic spikes at non-physiological rates. This infrequent but potentially lethal failure mode may be related to low battery voltage. Four single chamber pacemaker patients were analyzed (Medtronic Minix ST 8330, Minneapolis, MN, had been implanted in two patients and two CPI Triumph VR 1124, St Paul, MN, in the other two). They had been admitted because of presyncopal episodes. Typical high rate stimuli at 2000 ppm alternating with pacing at 60-65 ppm were recorded in all ECGs. Lead system tests were normal. The pulse generators had to be replaced.

Sacral Neuromodulation in Patients With a Cardiac Pacemaker

Directory of Open Access Journals (Sweden)

Abdullah A. Gahzi

2016-09-01

Full Text Available The objective of this study was to describe our experience using sacral neuromodulation to treat urinary urgency, frequency, urge incontinence, and chronic urinary retention in patients with cardiac pacemakers. With the increasingly widespread use of InterStim for bladder function restoration, we are seeing more complex patients with multiple comorbidities, including cardiac conditions. Herein, we report 3 cases of individuals with cardiac pacemakers who underwent InterStim implantation to treat urinary conditions. This study is a case series of 3 patients with cardiac pacemakers who underwent sacral neuromodulation to treat refractory voiding dysfunction. The initial patient screening for InterStim therapy involved percutaneous nerve evaluation (PNE, in which a temporary untined lead wire was placed through the S3 foramen. Patients who did not respond to PNE proceeded to a staged implant. All patients in this study had a greater than 50% improvement of their urinary symptoms during the initial trial and underwent placement of the InterStim implantable pulse generator (IPG. Postoperative programming was done under electrocardiogram monitoring by a cardiologist. No interference was observed between the Inter-Stim IPG and the cardiac pacemaker. In this group of patients, sacral neuromodulation in the presence of a cardiac pacemaker appears to have been safe.

Measuring pacemaker dose: A clinical perspective

Energy Technology Data Exchange (ETDEWEB)

Studenski, Matthew T., E-mail: matthew.studenski@jeffersonhospital.org [Department of Radiation Oncology at the Jefferson Medical College and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA (United States); Xiao Ying; Harrison, Amy S. [Department of Radiation Oncology at the Jefferson Medical College and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA (United States)

2012-07-01

Recently in our clinic, we have seen an increased number of patients presenting with pacemakers and defibrillators. Precautions are taken to develop a treatment plan that minimizes the dose to the pacemaker because of the adverse effects of radiation on the electronics. Here we analyze different dosimeters to determine which is the most accurate in measuring pacemaker or defibrillator dose while at the same time not requiring a significant investment in time to maintain an efficient workflow in the clinic. The dosimeters analyzed here were ion chambers, diodes, metal-oxide-semiconductor field effect transistor (MOSFETs), and optically stimulated luminescence (OSL) dosimeters. A simple phantom was used to quantify the angular and energy dependence of each dosimeter. Next, 8 patients plans were delivered to a Rando phantom with all the dosimeters located where the pacemaker would be, and the measurements were compared with the predicted dose. A cone beam computed tomography (CBCT) image was obtained to determine the dosimeter response in the kilovoltage energy range. In terms of the angular and energy dependence of the dosimeters, the ion chamber and diode were the most stable. For the clinical cases, all the dosimeters match relatively well with the predicted dose, although the ideal dosimeter to use is case dependent. The dosimeters, especially the MOSFETS, tend to be less accurate for the plans, with many lateral beams. Because of their efficiency, we recommend using a MOSFET or a diode to measure the dose. If a discrepancy is observed between the measured and expected dose (especially when the pacemaker to field edge is <10 cm), we recommend analyzing the treatment plan to see whether there are many lateral beams. Follow-up with another dosimeter rather than repeating multiple times with the same type of dosimeter. All dosimeters should be placed after the CBCT has been acquired.

Spanish Pacemaker Registry. Thirteenth Official Report of the Spanish Society of Cardiology Working Group on Cardiac Pacing (2015).

Science.gov (United States)

Pombo Jiménez, Marta; Cano Pérez, Óscar; Fidalgo Andrés, María Luisa; Lorente Carreño, Diego; Coma Samartín, Raúl

2016-12-01

We describe the results of the analysis of the devices implanted and conveyed to the Spanish Pacemaker Registry in 2015. The report is based on the processing of information provided by the European Pacemaker Patient Identification Card. We received information from 111 hospitals, with a total of 12 555 cards, representing 32.1% of all the estimated activity. The use of conventional generators and resynchronization devices was 820 and 73 units per million population, respectively. The mean age of the patients receiving an implantation was 77.7 years, and more than 50% of the devices were implanted in patients over 80 years of age. Overall, 58.6% of the implants and 58.8% of the replacements were performed in men. All of the endocardial leads employed were bipolar, 81.5% had an active fixation system, and 16.5% were compatible with magnetic resonance. Although dual chamber sequential pacing continues to be more widespread, pacing with VVI/R mode is used because up to 23.8% of the patients with sinus node disease are in sinus rhythm, as are 24.1% of those with atrioventricular block. The total use of pacemaker generators in Spain has increased by about 5% with respect to 2014. The majority of the leads implanted are of active fixation, and less than 20% are protected from magnetic resonance. The factors directly related to the selection of pacing mode are age and sex. In around 20% of patients, the choice of the pacing mode could be improved. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

[TRENDS OF PERMANENT PACEMAKER IMPLANTATION IN A SINGLE CENTER OVER A 20-YEAR PERIOD].

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Antonelli, Dante; Ilan, Limor Bushar; Freedberg, Nahum A; Feldman, Alexander; Turgeman, Yoav

2015-05-01

To review the changes in permanent pacemaker implantation indications, pacing modes and patients' demographics over a 20-year period. We retrospectively retrieved data on patients who underwent first implantation of the pacemaker between 1-1-1991 and 31-12-2010. One thousand and nine (1,009) patients underwent a first pacemaker implantation during that period; 535 were men (53%), their mean age was 74.6±19.5 years; the highest rate of implanted pacemaker was in patients ranging in age from 70-79 years, however there was an increasing number of patients aged over 80 years. The median survival time after initial pacemaker implantation was 8 years. Syncope was the most common symptom (62.5%) and atrioventricular block was the most common electrocardiographic indication (56.4%) leading to pacemaker implantation. There was increased utilization of dual chamber and rate responsive pacemakers over the years. There was no difference regarding mode selection between genders. Pacemaker implantation rates have increased over a 20-year period. Dual chamber replaced most of the single ventricular chamber pacemaker and rate responsive pacemakers became the norm. The data of a small volume center are similar to those reported in pacemaker surveys of high volume pacemaker implantation centers. They confirm adherence to the published guidelines for pacing.

Electromagnetic and radiation environments: effects on pacemakers

International Nuclear Information System (INIS)

Mouton, J.; Trochet, R.; Vicrey, J.; Sauvage, M.; Chauvenet, B.; Ostrovski, A.; Leroy, E.; Haug, R.; Dodinot, B.; Joffre, F.

1999-01-01

Nowadays, medical care development allows many people to share the benefits of implanted pacemakers (PM). PM can be perturbed and even fall in complete breakdowns in an electromagnetic and radiation environment. A stimuli-dependent patient can thus be seriously in danger. This article presents the effect of ionizing radiation from either a cobalt-60 source or from a linear accelerator (Saturne 43) on 12 pacemakers. It seems that technological progress make electronic circuits more sensitive to the cumulated dose of radiation. This survey shows that pacemakers have great difficulties to sustain ionizing radiation doses that are commonly delivered to patients during therapies. Usually perturbed functioning appears suddenly and means a strong shift of stimuli that might lead to heart failure

Bipolar Plates for PEM Systems

OpenAIRE

Lædre, Sigrid

2016-01-01

Summary of thesis: The Bipolar Plate (BPP) is an important component in both Proton Exchange Membrane Fuel Cells (PEMFCs) and Proton Exchange Membrane Water Electrolyzers (PEMWEs). Bipolar plate material and processing constitutes for a large fraction of the cost and weight of a PEM cell stack. The main tasks for the bipolar plates in both systems are to separate single cell in a stack, conduct current between single cells and remove heat from active areas. In addition, the BPPs distribu...

Enhanced low dose rate radiation effect test on typical bipolar devices

International Nuclear Information System (INIS)

Liu Minbo; Chen Wei; Yao Zhibin; He Baoping; Huang Shaoyan; Sheng Jiangkun; Xiao Zhigang; Wang Zujun

2014-01-01

Two types of bipolar transistors and nine types bipolar integrated circuit were selected in the irradiation experiment at different "6"0Co γ dose rate. The base current of bipolar transistor and input bias current of amplifier and comparator was measured, low dose enhance factor of test device was obtained. The results show that bipolar device have enhanced low dose rate sensitivity, enhancement factor of bipolar integrated circuit was bigger than that of transistor, and enhanced low dose rate sensitivity greatly varied with different structure and process of bipolar device. (authors)

From two competing oscillators to one coupled-clock pacemaker cell system

Science.gov (United States)

Yaniv, Yael; Lakatta, Edward G.; Maltsev, Victor A.

2015-01-01

At the beginning of this century, debates regarding “what are the main control mechanisms that ignite the action potential (AP) in heart pacemaker cells” dominated the electrophysiology field. The original theory which prevailed for over 50 years had advocated that the ensemble of surface membrane ion channels (i.e., “M-clock”) is sufficient to ignite rhythmic APs. However, more recent experimental evidence in a variety of mammals has shown that the sarcoplasmic reticulum (SR) acts as a “Ca2+-clock” rhythmically discharges diastolic local Ca2+ releases (LCRs) beneath the cell surface membrane. LCRs activate an inward current (likely that of the Na+/Ca2+ exchanger) that prompts the surface membrane “M-clock” to ignite an AP. Theoretical and experimental evidence has mounted to indicate that this clock “crosstalk” operates on a beat-to-beat basis and determines both the AP firing rate and rhythm. Our review is focused on the evolution of experimental definition and numerical modeling of the coupled-clock concept, on how mechanisms intrinsic to pacemaker cell determine both the heart rate and rhythm, and on future directions to develop further the coupled-clock pacemaker cell concept. PMID:25741284

Empirically supported psychosocial interventions for bipolar disorder: Current state of the research.

Science.gov (United States)

Salcedo, Stephanie; Gold, Alexandra K; Sheikh, Sana; Marcus, Peter H; Nierenberg, Andrew A; Deckersbach, Thilo; Sylvia, Louisa G

2016-09-01

Bipolar disorder requires psychiatric medications, but even guideline-concordant treatment fails to bring many patients to remission or keep them euthymic. To address this gap, researchers have developed adjunctive psychotherapies. The purpose of this paper is to critically review the evidence for the efficacy of manualized psychosocial interventions for bipolar disorder. We conducted a search of the literature to examine recent (2007-present), randomized controlled studies of the following psychotherapy interventions for bipolar disorder: psychoeducation (PE), cognitive behavioral therapy (CBT), interpersonal and social rhythm therapy (IPSRT), dialectical behavior therapy (DBT), mindfulness-based cognitive therapy (MBCT), and family therapies such as family focused therapy (FFT). All of the psychotherapy interventions appear to be effective in reducing depressive symptoms. Psychoeducation and CBT are associated with increased time to mood episode relapse or recurrence. MBCT has demonstrated a particular effectiveness in improving depressive and anxiety symptoms. Online psychotherapy interventions, programs combining one or more psychotherapy interventions, and targeted interventions centering on particular symptoms have been the focus of recent, randomized controlled studies in bipolar disorder. Psychotherapy interventions for the treatment of bipolar disorder have substantial evidence for efficacy. The next challenge will to disseminate these psychotherapies into the community. Copyright © 2016 Elsevier B.V. All rights reserved.

Thwarted interpersonal needs and suicide ideation: Comparing psychiatric inpatients with bipolar and non-bipolar mood disorders.

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Taylor, Nathanael J; Mitchell, Sean M; Roush, Jared F; Brown, Sarah L; Jahn, Danielle R; Cukrowicz, Kelly C

2016-12-30

Psychiatric inpatients are at heightened risk for suicide, and evidence suggests that psychiatric inpatients with bipolar mood disorders may be at greater risk for suicide ideation compared to those with non-bipolar mood disorders. There is a paucity of research directly comparing risk factors for suicide ideation in bipolar versus non-bipolar mood disorders in an inpatient sample. The current study sought to clarify the association between two constructs from the interpersonal theory of suicide (i.e., perceived burdensomeness and thwarted belongingness) in leading to suicide ideation among psychiatric inpatients with bipolar and non-bipolar mood disorders. Participants were (N=90) psychiatric inpatients with a bipolar (n = 20) or non-bipolar mood disorder (n=70; per their medical charts). Perceived burdensomeness, but not thwarted belongingness, was significantly associated with suicide ideation after adjusting for other covariates. This suggests perceived burdensomeness may play a key role in suicide ideation among psychiatric inpatients with any mood disorder and highlights the importance of assessment and intervention of perceived burdensomeness in this population. Contrary to our hypothesis, mood disorder group (i.e., bipolar versus non-bipolar) did not moderate the relations between perceived burdensomeness/thwarted belongingness and suicide ideation. Published by Elsevier Ireland Ltd.

Subacute right ventricle perforation by pacemaker lead presenting with left hemothorax and shock.

Science.gov (United States)

Nichols, Julianne; Berger, Natalie; Joseph, Praveen; Datta, Debapriya

2015-01-01

Cardiac perforation by pacemaker is a rare but potentially fatal complication. Acute perforations occurring within twenty-four hours of insertion of pacemaker can lead to hemopericardium, cardiac tamponade, and death. Hemothorax occurring as an acute complication of pacemaker insertion is reported but extremely rare. Previously, hemothorax and shock as a subacute complication following pacemaker insertion have not been reported. We report the case of an 85-year-old patient who presented with shock from hemothorax caused by pacemaker perforation, two weeks after insertion. Device interrogation showed normal function. Chest X-ray and echocardiogram missed lead dislocation and the diagnosis was made on computed tomogram (CT) of the chest. Following surgical repair, a new ventricular pacemaker was placed transvenously in the right ventricular septum. This case illustrates that CT scan of the chest should be performed in all patients in whom cardiac perforation by pacemaker is suspected but not diagnosed on chest X-ray and echocardiogram. Normal functioning of pacemaker on device interrogation does not exclude perforation.

Nuclear-powered pacemaker fuel cladding study

International Nuclear Information System (INIS)

Shoup, R.L.

1976-07-01

The fabrication of fuel capsules with refractory metal and alloy clads used in nuclear-powered cardiac pacemakers precludes the expedient dissolution of the clad in inorganic acid solutions. An experiment to measure penetration rates of acids on commonly used fuel pellet clads indicated that it is not impossible, but that it would be very difficult to dissolve the multiple cladding. This work was performed because of a suggestion that a 238 PuO 2 -powered pacemaker could be transformed into a terrorism weapon

Generic environmental statement on the routine use of plutonium-powered cardiac pacemakers

International Nuclear Information System (INIS)

Shoup, R.L.; Robinson, T.W.; O'Donnell, F.R.

1976-01-01

The purpose of a continuing program at ORNL is to provide technical assistance to the NRC on writing and editing of the final environmental statement on the routine use of nuclear-powered (primarily 238 Pu) cardiac pacemakers. This environmental statement defines the safety and reliability standards that nuclear-powered pacemakers are required to meet. All aspects of the risks to the patients, the public, and the environment are evaluated both for the routine use of plutonium-powered pacemakers and for postulated accidents involving pacemaker patients. Benefits derived from the use of plutonium-powered units are discussed and weighed against the risks in order to determine whether routine use is justified. Available alternative pacemakers with various performance characteristics are compared with respect to costs and to the needs of pacemaker patients

Global health resource utilization associated with pacemaker complications.

Science.gov (United States)

Waweru, Catherine; Steenrod, Anna; Wolff, Claudia; Eggington, Simon; Wright, David Jay; Wyrwich, Kathleen W

2017-07-01

To estimate health resource utilization (HRU) associated with the management of pacemaker complications in various healthcare systems. Electrophysiologists (EPs) from four geographical regions (Western Europe, Australia, Japan, and North America) were invited to participate. Survey questions focused on HRU in the management of three chronic pacemaker complications (i.e. pacemaker infections requiring extraction, lead fractures/insulation breaches requiring replacement, and upper extremity deep venous thrombosis [DVT]). Panelists completed a maximum of two web-based surveys (iterative rounds). Mean, median values, and interquartile ranges were calculated and used to establish consensus. Overall, 32 and 29 panelists participated in the first and second rounds of the Delphi panel, respectively. Consensus was reached on treatment and HRU associated with a typical pacemaker implantation and complications. HRU was similar across regions, except for Japan, where panelists reported the longest duration of hospital stay in all scenarios. Infections were the most resource-intensive complications and were characterized by intravenous antibiotics days of 9.6?13.5 days and 21.3?29.2 days for pocket and lead infections respectively; laboratory and diagnostic tests, and system extraction and replacement procedures. DVT, on the other hand, was the least resource intensive complication. The results of the panel represent the views of the respondents who participated and may not be generalizable outside of this panel. The surveys were limited in scope and, therefore, did not include questions on management of acute complications (e.g. hematoma, pneumothorax). The Delphi technique provided a reliable and efficient approach to estimating resource utilization associated with chronic pacemaker complications. Estimates from the Delphi panel can be used to generate costs of pacemaker complications in various regions.

Outcome and management of pacemaker-induced superior vena cava syndrome.

Science.gov (United States)

Fu, Hai-Xia; Huang, Xin-Miao; Zhong, Li; Osborn, Michael J; Bjarnason, Haraldur; Mulpuru, Siva; Zhao, Xian-Xian; Friedman, Paul A; Cha, Yong-Mei

2014-11-01

We aimed to determine the long-term outcomes of percutaneous lead extraction and stent placement in patients with pacemaker-induced superior vena cava (SVC) syndrome. The study retrospectively screened patients who underwent lead extraction followed by central vein stent implantation at Mayo Clinic (Rochester, MN, USA), from January 2005 to December 2012, to identify the patients with pacemaker-induced SVC syndrome. Demographic, clinical, and follow-up characteristics of those patients were collected from electronic medical records. Six cases were identified. The mean (standard deviation) age was 56 (15) years (male, 67%). All patients had permanent dual-chamber pacemakers, with a mean 11-year history of pacemaker placement. The entire device system was explanted in five patients; one patient had a 21-year-old pacemaker lead that could not be removed. Eight stents were implanted in six patients: five patients had one stent, one patient had three. A new pacemaker system was reimplanted through the stented vein in five patients. Technical success was achieved in all patients, without any complication. Symptoms rapidly resolved in all patients after stent deployment. The mean follow-up duration was 48 months (range, 10-100 months). Three patients remained symptom free. Reintervention with percutaneous balloon venoplasty was successful in three patients with symptom recurrence. Percutaneous stent implantation after lead removal followed by reimplantation of leads is a feasible alternative therapy for pacemaker-induced SVC syndrome, although some cases may require repeat intervention. ©2014 Wiley Periodicals, Inc.

Subclavian Vein Stenosis/Occlusion Following Transvenous Cardiac Pacemaker and Defibrillator Implantation: Incidence, Pathophysiology and Current Management

Directory of Open Access Journals (Sweden)

Brian O'Leary

2015-08-01

Full Text Available Subclavian vein stenosis is a common, but usually asymptomatic, complication following cardiac device placement. In addition to reviewing the literature on incidence, pathogenesis and management options for this important clinical problem, we describe two cases of symptomatic subclavian vein occlusion following pacemaker/defibrillator placement and successful treatment with venoplasty and stenting.

76 FR 64223 - Cardiovascular Devices; Reclassification of External Pacemaker Pulse Generator Devices

Science.gov (United States)

2011-10-17

... Drug Administration 21 CFR Part 870 Cardiovascular Devices; Reclassification of External Pacemaker... Special Controls Guidance Document: External Pacemaker Pulse Generator; Availability; Proposed Rule and... [Docket No. FDA-2011-N-0650] Cardiovascular Devices; Reclassification of External Pacemaker Pulse...

The cardiac pacemaker patient. Might the pacer be directly irradiated?

International Nuclear Information System (INIS)

Tsekos, A.; Momm, F.; Brunner, M.; Guttenberger, R.

2000-01-01

According to recommendations listed in a recent review, pacemakers generally should not be irradiated directly. They should be shielded from ionizing radiation or their position changed. Direct irradiation can cause pacemaker failure. There are no clinical signals to indicate a near failure. When controlling pacemaker function, there is often a change in the magnetic frequency before malfunction occurs. If a malfunction results in a partial heart failure only, there would be enough time to implant another pacemaker. As can be seen from a case described here, a policy of 'wait and see' may be adopted even if there are changes in the magnetic frequency. if there is any danger to the patient's life, the feasibility of using an external pacemaker system may be explored, especially in cases where there is a strong need for radiotherapy (severe pain, infiltration of plexus). Risks and benefits should be carefully weighed and discussed with the patient

Testing of Common Electromagnetic Environments for Risk of Interference with Cardiac Pacemaker Function

Directory of Open Access Journals (Sweden)

Maria Tiikkaja

2013-09-01

Conclusions: Modern pacemakers are well shielded against external EMFs, and workers with a pacemaker can most often return to their previous work after having a pacemaker implanted. However, an appropriate risk assessment is still necessary after the implantation of a pacemaker, a change of its generator, or major modification of its programming settings.

Patients exposure from fluoroscopic guided pacemaker implantation procedures

International Nuclear Information System (INIS)

Alkhorayef, M.; Babikir, E.; Sulieman, A.; Daar, E.; Alnaaimi, M.; Alduaij, M.; Bradley, D.

2016-10-01

A pacemaker, which is used for heart re synchronization with electrical impulses, is used to manage many clinical conditions. Recently, the frequency of the pacemaker implantation procedures increased 50% worldwide. During this procedure, patients and staff can be exposed to excessive radiation exposure. Wide range of doses was reported in previous studies, suggesting that optimization of this procedure is not fulfilled yet. This study aims to evaluate the patient and staff radiation doses during cardiac pacemaker procedure and quantify the patient effective dose. A total of 145 procedures were performed for five pacemakers procedures (VVI, VVIR, VVD, VVDR and DDDR) two hospitals were evaluated. Patients doses were measured using the kerma-area product meter. Effective doses were estimated using software based on Monte Carlo simulation from National Radiological Protection Board. The effective dose values were used to estimate the cancer risk from pacemaker procedure. Patients demographic data, exposure parameters for both fluoroscopy and radiography were quantified. The mean patients doses (Gy. cm 2 ) for VVI, VVIR, VVD, VVDR and DDDR was 1.52±0.13 (1.43-1.61), 3.28±2.34 (0.29-8.73), 3.04±1.67 (1.57-4.86), 6.04±2.326 and 19.2±3.6 (5.43-30.2), respectively, per procedure. The overall patients effective dose is 1.1 mSv per procedure. (Author)

Patients exposure from fluoroscopic guided pacemaker implantation procedures

Energy Technology Data Exchange (ETDEWEB)

Alkhorayef, M.; Babikir, E. [King Saud University, College of Applied Sciences, Radiological Sciences Department, P. O. Box 10219, Riyadh 11433 (Saudi Arabia); Sulieman, A. [Prince Sattam bin Abdulaziz University, College of Applied Medical Sciences, Radiology and Medical Imaging Department, P. O. Box 422, Alkharj 11942 (Saudi Arabia); Daar, E. [University of Jordan, Faculty of Science, Department of Physics, Amman 11942 (Jordan); Alnaaimi, M.; Alduaij, M. [Kuwait Cancer Control Centre, Department of Nuclear Medicine, Shwiekh (Kuwait); Bradley, D., E-mail: malkhorayef@ksu.edu.sa [University of Surrey, Centre for Nuclear and Radiation Physics, Guildford, Surrey, GU2 7XH (United Kingdom)

2016-10-15

A pacemaker, which is used for heart re synchronization with electrical impulses, is used to manage many clinical conditions. Recently, the frequency of the pacemaker implantation procedures increased 50% worldwide. During this procedure, patients and staff can be exposed to excessive radiation exposure. Wide range of doses was reported in previous studies, suggesting that optimization of this procedure is not fulfilled yet. This study aims to evaluate the patient and staff radiation doses during cardiac pacemaker procedure and quantify the patient effective dose. A total of 145 procedures were performed for five pacemakers procedures (VVI, VVIR, VVD, VVDR and DDDR) two hospitals were evaluated. Patients doses were measured using the kerma-area product meter. Effective doses were estimated using software based on Monte Carlo simulation from National Radiological Protection Board. The effective dose values were used to estimate the cancer risk from pacemaker procedure. Patients demographic data, exposure parameters for both fluoroscopy and radiography were quantified. The mean patients doses (Gy. cm{sup 2}) for VVI, VVIR, VVD, VVDR and DDDR was 1.52±0.13 (1.43-1.61), 3.28±2.34 (0.29-8.73), 3.04±1.67 (1.57-4.86), 6.04±2.326 and 19.2±3.6 (5.43-30.2), respectively, per procedure. The overall patients effective dose is 1.1 mSv per procedure. (Author)

Rhabdomyosarcoma associated with the lead wire of a pacemaker generator implant.

Science.gov (United States)

Thieman Mankin, Kelley M; Dunbar, Mark D; Toplon, David; Ginn, Pamela; Maisenbacher, Herbert W; Risselada, Marije

2014-06-01

An 11-year-old female spayed Labrador Retriever was presented for a draining, painful subcutaneous mass palpated over a previously implanted pacemaker generator. Infection was suspected and the mass was removed surgically. On cut surface, the mass was friable and mottled tan to brown with firm pale tan nodules, surrounding the pacemaker lead wire adjacent to the pacemaker generator. Cytologic interpretation of impression smears was consistent with a sarcoma, and suggestive of a rhabdomyosarcoma due to the presence of strap-like cells. On histopathologic examination, a highly invasive nodular mass surrounded the pacemaker lead, composed of pleomorphic round, spindle and strap cells, and multinucleated giant cells. The population exhibited microscopic invasion into the deep portion of the fibrous capsule surrounding the pacemaker generator. There were tumor emboli within small to medium subcutaneous veins adjacent to the mass. Immunohistochemically, the neoplastic cells stained positive for α-sarcomeric actin and vimentin, and negative for α-smooth muscle actin, consistent with a rhabdomyosarcoma arising at the site of the pacemaker generator. To our knowledge, this is the first report of a rhabdomyosarcoma associated with the lead wire of a pacemaker generator in a dog. © 2014 American Society for Veterinary Clinical Pathology and European Society for Veterinary Clinical Pathology.

The influence of electromagnetic interference and ionizing radiation on cardiac pacemakers

International Nuclear Information System (INIS)

Salmi, J.; Malmivuo, J.A.V.

1990-01-01

Adverse effects of the ionizing and non-ionizing electromagnetic fields on five pacemaker models have been tested. The study consisted of three parts: 1. measurement of magnetic fields in a radiotherapy room (microtron MM14), 2. the application of non-ionizing electromagnetic fields on pacemakers in a test laboratory (1 ... 1000 μT, 10 ... 10 000 Hz), and 3. the application of ionizing radiation of different types of radiotherapy devices on the pacemakers. The magnetic field strength in the microtron treatment room was found to be under 7.5 μT, which is one order of magnitude lower than the tolerance level obtained for the pacemakers in the test laboratory. All the tested pacemakers tolerated the ionizing radiation dose levels (less than 60 Gy) which are used in the radiotherapy. (orig.) [de

Discuss the cause and treatment of pacemaker lead dislocation and deal with

International Nuclear Information System (INIS)

Chen Yueguang; Zhang Dadong; Lu Jie; Yang Hui; Liu Chunyan; Zhang Wei

2003-01-01

Objective: To follow up the patients with pacemaker, observe the condition of pacemaker lead, to explore the cause of lead dislocation, to find out and prevent its occurrence. Methods: Summarizing the clinical data of 6 patients with pacemaker, 7 pacemaker leads with 8 time dislocation, pacemaker 2 DDDR, 2 DDD, 2 VVI. Results: Four patients were punctured from right subclavian vein, one from left subclavian vein and one from right brachiocephalic vein; four leads were dislocation in atrium and one mildly dislocation; four leads dislocation in ventricle and two mildly dislocation; There were 3 old women with 4 leads and 5 times of dislocation

Subacute Right Ventricle Perforation by Pacemaker Lead Presenting with Left Hemothorax and Shock

Directory of Open Access Journals (Sweden)

Julianne Nichols

2015-01-01

Full Text Available Cardiac perforation by pacemaker is a rare but potentially fatal complication. Acute perforations occurring within twenty-four hours of insertion of pacemaker can lead to hemopericardium, cardiac tamponade, and death. Hemothorax occurring as an acute complication of pacemaker insertion is reported but extremely rare. Previously, hemothorax and shock as a subacute complication following pacemaker insertion have not been reported. We report the case of an 85-year-old patient who presented with shock from hemothorax caused by pacemaker perforation, two weeks after insertion. Device interrogation showed normal function. Chest X-ray and echocardiogram missed lead dislocation and the diagnosis was made on computed tomogram (CT of the chest. Following surgical repair, a new ventricular pacemaker was placed transvenously in the right ventricular septum. This case illustrates that CT scan of the chest should be performed in all patients in whom cardiac perforation by pacemaker is suspected but not diagnosed on chest X-ray and echocardiogram. Normal functioning of pacemaker on device interrogation does not exclude perforation.

Complications of pacemaker therapy in adults with congenital heart disease: a multicenter study.

Science.gov (United States)

Opić, Petra; van Kranenburg, Matthijs; Yap, Sing-Chien; van Dijk, Arie P; Budts, Werner; Vliegen, Hubert W; van Erven, Lieselot; Can, Anil; Sahin, Gulhan; Theuns, Dominic A M J; Witsenburg, Maarten; Roos-Hesselink, Jolien W

2013-10-09

This study aims to investigate indications and complications of permanent cardiac pacing in adults with congenital heart disease (CHD). Two-hundred and seventy-four CHD patients were identified who underwent permanent pacemaker implantation between 1972 and 2009. The indication for pacing was acquired sinus node or AV node conduction disease (63%), sinus node or AV node conduction disease after cardiac surgery (28%), and drug/arrhythmia-related indications (9%). Patients with complex CHD received a pacemaker at younger age (23 versus 31 years, ppacemaker implantation (general population: 5.2%). The most common acute complications were lead dysfunction (4.0%), bleeding (2.6%), pocket infection (1.5%) and pneumothorax (1.5%). During a median follow-up of 12 years, pacemaker-related complications requiring intervention occurred in 95 patients (34.6%). The most common late pacemaker-related complications included lead failure (24.8%), pacemaker dysfunction/early battery depletion (5.1%), pacemaker migration (4.7%) and erosion (4.7%). Pacemaker implantation at younger age (pacemaker-related complication (adjusted hazard ratio 1.68, 95% confidence interval 1.07 to 2.63, p=0.023). The risk of periprocedural complications seems higher in the CHD population compared to the general population and more than one-third of CHD patients encountered a pacemaker-related complication during long-term follow-up. This risk increases for those who receive a pacemaker at younger age. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

Interference of apex locator, pulp tester and diathermy on pacemaker function.

Science.gov (United States)

Sriman, Narayanan; Prabhakar, V; Bhuvaneswaran, J S; Subha, N

2015-01-01

The purpose of this study was to evaluate the effects of three electronic apex locators (EAL), electric pulp tester (EPT) and diathermy on pacemaker function in vitro. Three EALs: Root ZX (J. Morita Co., Tustin, CA, U.S.A.), Propex (Dentsply), Mini Apex locator (SybronEndo, Anaheim, CA, USA), EPT (Parkell pulp vitality tester Farmingdale, NY, USA) and Diathermy (Neomed 250 B) were tested for any interference with one pacemaker (A medtronic kappa KVDD901-serial number: PLE734632S). Directly connecting the pacemaker lead with the EAL/EPT/diathermy operating on a flat bench top, the telemetry wand was held directly over the pacemaker to monitor the pacing pattern for a period of 30 s. Pacemaker activity was continuously recorded on the telemetric programmer and electro gram (EGM) readings examined for pacer inhibition, noise reversion or inappropriate pacemaker pulses. All the three apex locators showed no pacing interference or background noise during its function or at rest. The EGM readings of EPT showed varying levels of background noise in between pacing however, this did not affect the normal pacing pattern and the pacing interval remained constant. EGM readings of diathermy showed an increase in the pacing interval (irregular pacing pattern) followed by complete inhibition of the pacing system. The tested EALs do not interfere with cardiac pacemaker function. The tested EPT showed varying levels of background noise but does not interfere with cardiac pacemaker function. Use of Diathermy interfered with the normal pacing, leading to complete inhibition of the pacing system.

Bipolar disorder and complementary medicine: current evidence, safety issues, and clinical considerations.

Science.gov (United States)

Sarris, Jerome; Lake, James; Hoenders, Rogier

2011-10-01

Bipolar disorder (BD) is a debilitating syndrome that is often undiagnosed and undertreated. Population surveys show that persons with BD often self-medicate with complementary and alternative medicine (CAM) or integrative therapies in spite of limited research evidence supporting their use. To date, no review has focused specifically on nonconventional treatments of BD. The study objectives were to present a review of nonconventional (complementary and integrative) interventions examined in clinical trials on BD, and to offer provisional guidelines for the judicious integrative use of CAM in the management of BD. PubMed, CINAHL,(®) Web of Science, and Cochrane Library databases were searched for human clinical trials in English during mid-2010 using Bipolar Disorder and CAM therapy and CAM medicine search terms. Effect sizes (Cohen's d) were also calculated where data were available. Several positive high-quality studies on nutrients in combination with conventional mood stabilizers and antipsychotic medications in BD depression were identified, while branched-chain amino acids and magnesium were effective (small studies) in attenuating mania in BD. In the treatment of bipolar depression, evidence was mixed regarding omega-3, while isolated studies provide provisional support for a multinutrient formula, n-acetylcysteine, and l-tryptophan. In one study, acupuncture was found to have favorable but nonsignificant effects on mania and depression outcomes. Current evidence supports the integrative treatment of BD using combinations of mood stabilizers and select nutrients. Other CAM or integrative modalities used to treat BD have not been adequately explored to date; however, some early findings are promising. Select CAM and integrative interventions add to established conventional treatment of BD and may be considered when formulating a treatment plan. It is hoped that the safety issues and clinical considerations addressed in this article may encourage the practice

Deactivation of Pacemaker: Ethical Approach or Managerial Failure?

Directory of Open Access Journals (Sweden)

Macková Marie

2017-12-01

Full Text Available The decision about the deactivation of a pacemaker must be the result of a multicriteria decision-making process where the legal, ethical and effectiveness aspects must be taken into account and delicately balanced, while also considering the risk of managerial failure. Academic as well as professional discussion is necessary because there is a whole range of question marks on this topic and all the aspects mentioned above. The aim of this paper is to contribute to the debate by presenting the views of Czech physicians about the possibility of deactivation of the pacemaker in patients in terminal states. Based on the results of our research, the following steps are recommended to enable the deactivation of pacemakers in the Czech environment. Before the patient’s own indication of pacemaker therapy, treatment should be discussed with the patient in detail, including complications and deactivation options. Czech ethical consultant services should be set up in Czech hospitals. And last but not least, they should take an opinion on this issue as well as the professional society.

A four-diode full-wave ionic current rectifier based on bipolar membranes: overcoming the limit of electrode capacity.

Science.gov (United States)

Gabrielsson, Erik O; Janson, Per; Tybrandt, Klas; Simon, Daniel T; Berggren, Magnus

2014-08-13

Full-wave rectification of ionic currents is obtained by constructing the typical four-diode bridge out of ion conducting bipolar membranes. Together with conjugated polymer electrodes addressed with alternating current, the bridge allows for generation of a controlled ionic direct current for extended periods of time without the production of toxic species or gas typically arising from electrode side-reactions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Possible health hazards for cardiac pacemaker wearers from exposure to electromagnetic fields

Energy Technology Data Exchange (ETDEWEB)

1988-03-01

Cardiac pacemakers are used to provide electrical stimulation to the heart when the heart's natural rhythm is interrupted. This study shows that they can be susceptible to electromagnetic fields. Pacemakers are well protected against common electromagnetic fields, such as those from household appliances. But intense electomagnetic fields, such as those found in some industrial settings, could affect the functioning of the pacemaker. Such interference may cause the pacemaker wearer to feel dizzy or experience an accelerated heartbeat. While this is not fatal, the pacemaker wearer should try to move away from the source of the interfering field and avoid situations in which interference could arise. After experiencing any of these symptoms, the pacemaker wearer should contact a physician. Potential sources of electromagnetic interference should be identified and characterized to determine if there could be an interference hazard. Exposure to interfering electomagnetic fields should be minimized. 7 refs., 1 fig.

Swim pacemakers in box jellyfish are modulated by the visual input

DEFF Research Database (Denmark)

Garm, Anders Lydik; Bielecki, Jan

2008-01-01

A major part of the cubozoan central nervous system is situated in the eye-bearing rhopalia. One of the neuronal output channels from the rhopalia carries a swim pacemaker signal, which has a one-to-one relation with the swim contractions of the bell shaped body. Given the advanced visual system...... of box jellyfish and that the pacemaker signal originates in the vicinity of these eyes, it seems logical to assume that the pacemakers are modified by the visual input. Here, the firing frequency and distribution of inter-signal intervals (ISIs) of single pacemakers are examined in the Caribbean box...

State of the art of cardiac pacemaker technology

International Nuclear Information System (INIS)

Lambeck, R.

1978-01-01

The development of cardiac pacemakers from fixed-frequency to demand pacemakers is reviewed. The latter is described in more detail with regard to its energy sources and its design. The use of radioactive energy sources is illustrated by the example of 238 Pu and 147 promethium and a comparison of the two radiation sources. (AJ) 891 AJ [de

Cardiac pacemaker dysfunction in children after thoracic drainage catheter manipulation.

Science.gov (United States)

Lobdell, K W; Walters, H L; Hudson, C; Hakimi, M

1997-05-01

Two children underwent placement of permanent, epicardial-lead, dual-chamber, unipolar pacemaker systems for complete heart block. Postoperatively, both patients demonstrated subcutaneous emphysema-in the area of their pulse generators-temporally related to thoracic catheter manipulation. Acutely, each situation was managed with manual compression of the pulse generator, ascertaining appropriate pacemaker sensing and pacing. Maintenance of compression with pressure dressings, vigilant observation/monitoring, and education of the care givers resulted in satisfactory pacemaker function without invasive intervention.

Comparative familial aggregation of bipolar disorder in patients with bipolar I and bipolar II disorders.

Science.gov (United States)

Parker, Gordon B; Romano, Mia; Graham, Rebecca K; Ricciardi, Tahlia

2018-05-01

We sought to quantify the prevalence and differential prevalence of a bipolar disorder among family members of patients with a bipolar I or II disorder. The sample comprised 1165 bipolar and 1041 unipolar patients, with the former then sub-typed as having either a bipolar I or II condition. Family history data was obtained via an online self-report tool. Prevalence of a family member having a bipolar disorder (of either sub-type) was distinctive (36.8%). Patients with a bipolar I disorder reported a slightly higher family history (41.2%) compared to patients with a bipolar II disorder (36.3%), and with both significantly higher than the rate of bipolar disorder in family members of unipolar depressed patients (18.5%). Findings support the view that bipolar disorder is heritable. The comparable rates in the two bipolar sub-types support the positioning of bipolar II disorder as a valid condition with strong genetic underpinnings.

Acute pericarditis with cardiac tamponade induced by pacemaker implantation.

Science.gov (United States)

Shingaki, Masami; Kobayashi, Yutaka; Suzuki, Haruo

2015-11-01

An 87-year-old woman was diagnosed with third-degree atrioventricular block and underwent pacemaker implantation. On postoperative day 12, she experienced cardiac tamponade that was suspected on computed tomography to be caused by lead perforation; therefore, we performed open-heart surgery. However, we could not identify a perforation site on the heart, and drained a 400-mL exudative pericardial effusion. Subsequently, we diagnosed the pericardial effusion as due to pericarditis induced by pacemaker implantation. It is sometimes difficult to distinguish pericarditis from pacemaker lead perforation, so both should be included in the differential diagnosis. © The Author(s) 2014.

Is pacemaker therapy the right key to patients with vasovagal syncope?

Science.gov (United States)

Radovanović, Nikola N; Kirćanski, Bratislav; Raspopović, Srdjan; Pavlović, Siniša U; Jovanović, Velibor; Milašinović, Goran

2016-01-01

Vasovagal syncope is the most common type of reflex syncope. Efficacy of cardiac pacing in this indication has not been the subject of many studies and pacemaker therapy in patients with vasovagal syncope is still controversial. This study aimed to assess the efficacy and safety of pacing therapy in treatment of patients with vasovagal syncope, to determine contribution of new therapeutic models in increasing its success, and to identify risk factors associated with a higher rate of symptoms after pacemaker implantation. A retrospective study included 30 patients with pacemaker implanted due to vasovagal syncope in the Pacemaker Center, Clinical Center of Serbia, between November 2003 and June 2014. Head-up tilt test was performed to diagnose vasovagal syncope. Patients with cardioinhibitory and mixed type of disease were enrolled in the study. Mean age was 48.1 ± 11.1 years and 18 (60%) patients were men. Mean follow-up period was 5.9 ± 3.0 years. Primarily, implantable loop recorder was implanted in 10 (33.3%) patients. Twenty (66.7%) patients presented cardioinhibitory and 10 (33.3%) mixed type of vasovagal syncope. After pacemaker implantation, 11 (36.7%) patients had syncope. In multiple logistic regression analysis we showed that syncope is statistically more likely to occur after pacemaker implantation in patients with mixed type of vasovagal syncope (p = 0.018). There were two (6.7%) perioperative surgical complications. Pacemaker therapy is a safe treatment for patients with vasovagal syncope, whose efficacy can be improved by strict selection of patients. We showed that symptoms occur statistically more often in patients with mixed type of disease after pacemaker implantation.

Multiple photoreceptor systems control the swim pacemaker activity in box jellyfish

DEFF Research Database (Denmark)

Garm, Anders Lydik; Mori, S.

2009-01-01

Like all other cnidarian medusae, box jellyfish propel themselves through the water by contracting their bell-shaped body in discrete swim pulses. These pulses are controlled by a swim pacemaker system situated in their sensory structures, the rhopalia. Each medusa has four rhopalia each with a s......Like all other cnidarian medusae, box jellyfish propel themselves through the water by contracting their bell-shaped body in discrete swim pulses. These pulses are controlled by a swim pacemaker system situated in their sensory structures, the rhopalia. Each medusa has four rhopalia each...... with a similar set of six eyes of four morphologically different types. We have examined how each of the four eye types influences the swim pacemaker. Multiple photoreceptor systems, three of the four eye types, plus the rhopalial neuropil, affect the swim pacemaker. The lower lens eye inhibits the pacemaker...... when stimulated and provokes a strong increase in the pacemaker frequency upon light-off. The upper lens eye, the pit eyes and the rhopalial neuropil all have close to the opposite effect. When these responses are compared with all-eye stimulations it is seen that some advanced integration must take...

Integrated neurobiology of bipolar disorder

Directory of Open Access Journals (Sweden)

Vladimir eMaletic

2014-08-01

Full Text Available From a neurobiological perspective there is no such thing as bipolar disorder. Rather, it is almost certainly the case that many somewhat similar, but subtly different, pathological conditions produce a disease state that we currently diagnose as bipolarity. This heterogeneity—reflected in the lack of synergy between our current diagnostic schema and our rapidly advancing scientific understanding of the condition—limits attempts to articulate an integrated perspective on bipolar disorder. However, despite these challenges, scientific findings in recent years are beginning to offer a provisional unified field theory of the disease. This theory sees bipolar disorder as a suite of related neurodevelopmental conditions with interconnected functional abnormalities that often appear early in life and worsen over time. In addition to accelerated loss of volume in brain areas known to be essential for mood regulation and cognitive function, consistent findings have emerged at a cellular level, providing evidence that bipolar disorder is reliably associated with dysregulation of glial-neuronal interactions. Among these glial elements are microglia—the brain’s primary immune elements, which appear to be overactive in the context of bipolarity. Multiple studies now indicate that inflammation is also increased in the periphery of the body in both the depressive and manic phases of the illness, with at least some return to normality in the euthymic state. These findings are consistent with changes in the HPA axis, which are known to drive inflammatory activation. In summary, the very fact that no single gene, pathway or brain abnormality is likely to ever account for the condition is itself an extremely important first step in better articulating an integrated perspective on both its ontological status and pathogenesis. Whether this perspective will translate into the discovery of innumerable more homogeneous forms of bipolarity is one of the great

Continued evaluation of cardiac pacemakers. Annual report Jun 73-31 Aug 75

International Nuclear Information System (INIS)

Brueschke, E.E.; Uretz, E.F.; Hauser, R.G.

1976-01-01

The nuclear powered pacemaker evaluation was designed to characterize the operating characteristics of such pacemakers and identify potential failure mechanisms. More than 30 nuclear powered pacemakers were implanted in dogs and 15 were subjected to high stress bench tests. This evaluation resulted in the identification of several basic pacemaker problem areas for the batteries under test. These included abrupt and gradual nuclear battery failures, weld seam defects (in one model) resulting in pulse generator failures, pulse generator lead connector defects and pulse generator electronic malfunctions

I-123 metaiodobenzylguanidine cardiac scintigraphy in patients with an implanted permanent pacemaker

International Nuclear Information System (INIS)

Nakata, Akio; Hirota, Satoshi; Tsuji, Hiroshi; Takazakura, Eisuke

1995-01-01

Tl scintigraphic abnormalities have been reported in patients with an implanted permanent pacemaker, but little is known about the MIBG scintigraphic findings in such patients. This study was performed to assess the MIBG scintigraphic findings in patients with an implanted permanent pacemaker, and to test the hypothesis that imaging characteristics of MIBG scintigraphy differ according to its mode. Twelve patients (4 men and 8 women, mean age: 72.4±9.5 years), who had undergone the implantation of a permanent pacemaker for bradyarrhythmias, underwent MIBG scintigraphy. The patients were divided into VVI pacemaker and DDD pacemaker groups. The tomograms were divided into nine segments and the MIBG defect in each segment scored on a scale ranging from 0 (normal uptake) to 3 (no uptake). Total MIBG defect scores were generated by summing the scores for the nine segments in each patient. MIBG scintigraphic abnormalities were found in ten of the twelve patients. The six patients with the VVI pacemaker manifested MIBG scintigraphic abnormalities. These MIBG scintigraphic abnormalities were observed in all segments, particularly in the posterior segments. The mean total defect score of the VVI group was higher than that of the DDD group (14.8±9.8 vs 3.0±3.5, respectively p<0.05). Therefore, we conclude that despite several limitations of the study, MIBG scintigraphic abnormalities occur in patients with implanted permanent pacemakers, and that such abnormalities are more prominent with the VVI than DDD pacemaker. (author)

Setups for in vitro assessment of RFID interference on pacemakers

International Nuclear Information System (INIS)

Mattei, E; Censi, F; Delogu, A; Ferrara, A; Calcagnini, G

2013-01-01

The aim of this study is to propose setups for in vitro assessment of RFID (radiofrequency identification) interference on pacemakers (PM). The voltage induced at the input stage of the PM by low-frequency (LF) and high-frequency (HF) RFID transmitters has been used to quantify the amount of the interference. A commercial PM was modified in order to measure the voltage at its input stage when exposed to a sinusoidal signal at 125 kHz and 13.56 MHz. At both frequencies, two antennas with different dimensions (diameter = 10 cm and 30 cm, respectively) were used to generate the interfering field, and the induced voltage was measured between the lead tip and the PM case (unipolar voltage), and between the tip and ring electrodes (bipolar voltage). The typical lead configurations adopted in similar studies or proposed by international standards, as well as lead paths closer to actual physiological implants were tested. At 125 kHz, the worst-case condition differs for the two antennas: the 10 cm antenna induced the highest voltage in the two-loop spiral configuration, whereas the 30 cm antenna in the 225 cm 2 loop configuration. At 13.56 MHz, the highest voltage was observed for both the antennas in the 225 cm 2 loop configuration. Bipolar voltages were found to be lower than the unipolar voltages induced in the same configurations, this difference being not as high as one could expect from theoretical considerations. The worst-case scenario, in terms of the induced voltage at the PM input stage, has been identified both for LF and HF readers, and for two sizes of transmitting antennas. These findings may provide the basis for the definition of a standard implant configuration and a lead path to test the EMI effects of LF and HF RFID transmitters on active implantable devices. (paper)

The rationale and design of the Micra Transcatheter Pacing Study: safety and efficacy of a novel miniaturized pacemaker.

Science.gov (United States)

Ritter, Philippe; Duray, Gabor Z; Zhang, Shu; Narasimhan, Calambur; Soejima, Kyoko; Omar, Razali; Laager, Verla; Stromberg, Kurt; Williams, Eric; Reynolds, Dwight

2015-05-01

Recent advances in miniaturization technologies and battery chemistries have made it possible to develop a pacemaker small enough to implant within the heart while still aiming to provide similar battery longevity to conventional pacemakers. The Micra Transcatheter Pacing System is a miniaturized single-chamber pacemaker system that is delivered via catheter through the femoral vein. The pacemaker is implanted directly inside the right ventricle of the heart, eliminating the need for a device pocket and insertion of a pacing lead, thereby potentially avoiding some of the complications associated with traditional pacing systems. The Micra Transcatheter Pacing Study is currently undergoing evaluation in a prospective, multi-site, single-arm study. Approximately 720 patients will be implanted at up to 70 centres around the world. The study is designed to have a continuously growing body of evidence and data analyses are planned at various time points. The primary safety and efficacy objectives at 6-month post-implant are to demonstrate that (i) the percentage of Micra patients free from major complications related to the Micra system or implant procedure is significantly higher than 83% and (ii) the percentage of Micra patients with both low and stable thresholds is significantly higher than 80%. The safety performance benchmark is based on a reference dataset of 977 subjects from 6 recent pacemaker studies. The Micra Transcatheter Pacing Study will assess the safety and efficacy of a miniaturized, totally endocardial pacemaker in patients with an indication for implantation of a single-chamber ventricular pacemaker. NCT02004873. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Subjective consequences of permanent pacemaker therapy in patients under the age of retirement

DEFF Research Database (Denmark)

Mickley, H; Petersen, J; Nielsen, B L

1989-01-01

During a 5-year period, 81 patients ages 20 to 60 years old had implantation of a permanent cardiac pacemaker at the University Hospital, Odense. At follow-up, during 1985, the 73 survivors received a semi-structured questionnaire regarding subjective consequences of pacemaker therapy, and 72...... people (98.6%) agreed to participate. The mean pacing period (range) was 33.8 (11-72) months. Surgical intervention was required in 14 patients (19.4%) during follow-up. Regarding all symptoms 67 patients (93.1%) perceived benefit from the pacemaker. The effectiveness of cardiac pacing was most...... or a sensation of "impulses"/palpitations. To the majority (49 patients or 68.1%) pacemaker treatment did not influence quality of sexual activity. Six patients (8.3%) perceived an improvement, whereas a corresponding number felt deterioration in sexual activity following pacemaker implantation. Pacemaker...

Transcranial direct-current stimulation (tDCS) for bipolar depression: A systematic review and meta-analysis.

Science.gov (United States)

Dondé, Clément; Amad, Ali; Nieto, Isabel; Brunoni, André Russowsky; Neufeld, Nicholas H; Bellivier, Frank; Poulet, Emmanuel; Geoffroy, Pierre-Alexis

2017-08-01

Bipolar disorder (BD) is a severe and recurrent brain disorder that can manifest in manic or depressive episodes. Transcranial Direct Current Stimulation (tDCS) has been proposed as a novel therapeutic modality for patients experiencing bipolar depression, for which standard treatments are often inefficient. While several studies have been conducted in this patient group, there has been no systematic review or meta-analysis that specifically examines bipolar depression. We aimed to address this gap in the literature and evaluated the efficacy and tolerability of tDCS in patients fulfilling DSM-IV-TR criteria for BD I, II, or BD not otherwise specified (NOS). We systematically searched the literature from April 2002 to November 2016 to identify relevant publications for inclusion in our systematic review and meta-analysis. Effect sizes for depression rating-scale scores were expressed as the standardized mean difference (SMD) before and after tDCS. Thirteen of 382 identified studies met eligibility criteria for our systematic review. The meta-analysis included 46 patients from 7 studies with depression rating-scale scores pre- and post-tDCS. Parameters of tDCS procedures were heterogeneous. Depression scores decreased significantly with a medium effect size after acute-phase of treatment (SMD 0.71 [0.25-1.18], z=3.00, p=0.003) and at the furthest endpoint (SMD 1.27 [0.57-1.97], z=3.57, p=0.0004). Six cases of affective switching under tDCS treatment protocols were observed. Depressive symptoms respond to tDCS in patients with BD. Additional studies, and particularly randomized controlled trials, are needed to clarify the effectiveness of tDCS in bipolar depression, the frequency of tDCS-emergent hypomania/mania, and which tDCS modalities are most efficient. Copyright © 2017 Elsevier Inc. All rights reserved.

Bipolar Disorder and Obsessive Compulsive Disorder Comorbidity

Directory of Open Access Journals (Sweden)

Necla Keskin

2014-08-01

Full Text Available The comorbidity of bipolar disorder and anxiety disorders is a well known concept. Obsessive-compulsive disorder is the most commonly seen comorbid anxiety disorder in bipolar patients. Some genetic variants, neurotransmitters especially serotonergic systems and second-messenger systems are thought to be responsible for its etiology. Bipolar disorder alters the clinical aspects of obsessive compulsive disorder and is associated with poorer outcome. The determination of comorbidity between bipolar disorder and obsessive compulsive disorder is quite important for appropriate clinical management and treatment. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(4.000: 429-437

Twiddler-syndrom er en årsag til pacemaker elektrode displacering

DEFF Research Database (Denmark)

Grønbech, Keea Treu; Hansen, Michael Gilså

2013-01-01

Twiddler's syndrome is a rare cause of pacemaker electrode displacement. The displacement is caused by the patient's manipulation with the pacemaker, so the electrode is retracted. We describe a case of a 79-year-old overweight woman with a known psychiatric anamnesis, who was admitted twice...... with twiddler's syndrome. Age and overweight are known risk factors for twiddler's syndrome; and in this case the patient's psychiatric habitus was probably an additional risk factor. Before performing a pacemaker implantation it is important to take the patient's risk factors into account, and thus consider...

Integrative Modeling of Electrical Properties of Pacemaker Cardiac Cells

Science.gov (United States)

Grigoriev, M.; Babich, L.

2016-06-01

This work represents modeling of electrical properties of pacemaker (sinus) cardiac cells. Special attention is paid to electrical potential arising from transmembrane current of Na+, K+ and Ca2+ ions. This potential is calculated using the NaCaX model. In this respect, molar concentration of ions in the intercellular space which is calculated on the basis of the GENTEX model is essential. Combined use of two different models allows referring this approach to integrative modeling.

Tricuspid valve repair for severe tricuspid regurgitation due to pacemaker leads.

Science.gov (United States)

Uehara, Kyokun; Minakata, Kenji; Watanabe, Kentaro; Sakaguchi, Hisashi; Yamazaki, Kazuhiro; Ikeda, Tadashi; Sakata, Ryuzo

2016-07-01

Tricuspid valve regurgitation due to pacemaker leads is a well-known complication. Although some reports have suggested that pacemaker leads should be surgically explanted, strongly adhered leads cannot always be removed. The aim of this study was to describe our tricuspid valve repair techniques with pacemaker leads left in situ. Our retrospective study investigated 6 consecutive patients who required tricuspid valve surgery for severe regurgitation induced by pacemaker leads. From the operative findings, we identified 3 patterns of tricuspid valve and pacemaker lead involvement. In 3 patients, the leads were caught in the chordae, in 2 patients, tricuspid regurgitation was caused by lead impingement on the septal leaflet, and in 3 patients, tricuspid valve leaflets had been perforated by the pacemaker leads. During surgery, all leads were left in situ after being separated from the leaflet or valvular apparatus. In addition, suture annuloplasty was performed for annular dilatation in all cases. In one patient, the lead was reaffixed to the annulus after the posterior leaflet was cut back towards the annulus, and the leaflet was then closed. There was one hospital death due to sepsis. The degree of tricuspid regurgitation was trivial in all surviving patients at discharge. During a mean follow-up of 21 months, one patient died from pneumonia 20 months after tricuspid valve repair. In patients undergoing tricuspid valve surgery due to severe tricuspid regurgitation caused by pacemaker leads, the leads can be left in situ after proper repair with annuloplasty. © The Author(s) 2016.

Early Intervention in Bipolar Disorder.

Science.gov (United States)

Vieta, Eduard; Salagre, Estela; Grande, Iria; Carvalho, André F; Fernandes, Brisa S; Berk, Michael; Birmaher, Boris; Tohen, Mauricio; Suppes, Trisha

2018-05-01

Bipolar disorder is a recurrent disorder that affects more than 1% of the world population and usually has its onset during youth. Its chronic course is associated with high rates of morbidity and mortality, making bipolar disorder one of the main causes of disability among young and working-age people. The implementation of early intervention strategies may help to change the outcome of the illness and avert potentially irreversible harm to patients with bipolar disorder, as early phases may be more responsive to treatment and may need less aggressive therapies. Early intervention in bipolar disorder is gaining momentum. Current evidence emerging from longitudinal studies indicates that parental early-onset bipolar disorder is the most consistent risk factor for bipolar disorder. Longitudinal studies also indicate that a full-blown manic episode is often preceded by a variety of prodromal symptoms, particularly subsyndromal manic symptoms, therefore supporting the existence of an at-risk state in bipolar disorder that could be targeted through early intervention. There are also identifiable risk factors that influence the course of bipolar disorder, some of them potentially modifiable. Valid biomarkers or diagnosis tools to help clinicians identify individuals at high risk of conversion to bipolar disorder are still lacking, although there are some promising early results. Pending more solid evidence on the best treatment strategy in early phases of bipolar disorder, physicians should carefully weigh the risks and benefits of each intervention. Further studies will provide the evidence needed to finish shaping the concept of early intervention. AJP AT 175 Remembering Our Past As We Envision Our Future April 1925: Interpretations of Manic-Depressive Phases Earl Bond and G.E. Partridge reviewed a number of patients with manic-depressive illness in search of a unifying endo-psychic conflict. They concluded that understanding either phase of illness was "elusive" and

Dosimetric perturbations due to an implanted cardiac pacemaker in MammoSite{sup Registered-Sign} treatment

Energy Technology Data Exchange (ETDEWEB)

Sung, Wonmo; Kim, Siyong; Kim, Jung-in; Lee, Jae-gi; Shin, Young-Joo; Jung, Jae-Yong; Ye, Sung-Joon [Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul 110-799, South Korea and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744 (Korea, Republic of); Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida 32224 (United States); Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul 110-799, South Korea and Department of Radiation Oncology, Kangbuk Samsung Medical Center, Seoul 110-746 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744, South Korea and Department of Biomedical Radiation Sciences, Seoul National University, Seoul 151-742 (Korea, Republic of); Department of Radiation Oncology, Sanggye Paik Hospital, Inje University, Seoul 139-707 (Korea, Republic of); Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744 (Korea, Republic of); Department of Biomedical Radiation Sciences, Seoul National University, Seoul 151-742 (Korea, Republic of); Department of Radiation Oncology, Seoul National University, Seoul 110-799 (Korea, Republic of) and Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of)

2012-10-15

Purpose: To investigate dose perturbations for pacemaker-implanted patients in partial breast irradiation using high dose rate (HDR) balloon brachytherapy. Methods: Monte Carlo (MC) simulations were performed to calculate dose distributions involving a pacemaker in Ir-192 HDR balloon brachytherapy. Dose perturbations by varying balloon-to-pacemaker distances (BPD = 50 or 100 mm) and concentrations of iodine contrast medium (2.5%, 5.0%, 7.5%, and 10.0% by volume) in the balloon were investigated for separate parts of the pacemaker (i.e., battery and substrate). Relative measurements using an ion-chamber were also performed to confirm MC results. Results: The MC and measured results in homogeneous media without a pacemaker agreed with published data within 2% from the balloon surface to 100 mm BPD. Further their dose distributions with a pacemaker were in a comparable agreement. The MC results showed that doses over the battery were increased by a factor of 3, compared to doses without a pacemaker. However, there was no significant dose perturbation in the middle of substrate but up to 70% dose increase in the substrate interface with the titanium capsule. The attenuation by iodine contrast medium lessened doses delivered to the pacemaker by up to 9%. Conclusions: Due to inhomogeneity of pacemaker and contrast medium as well as low-energy photons in Ir-192 HDR balloon brachytherapy, the actual dose received in a pacemaker is different from the homogeneous medium-based dose and the external beam-based dose. Therefore, the dose perturbations should be considered for pacemaker-implanted patients when evaluating a safe clinical distance between the balloon and pacemaker.

Hemodynamic instability after pulmonary veins isolation in a patient with dual chamber pacemaker

Science.gov (United States)

Kiuchi, Márcio Galindo; Lobato, Guilherme Miglioli; Chen, Shaojie

2017-01-01

Abstract Introduction: The standard treatment of sinus node dysfunction (SND) is the pacemaker implantation, and the ideal methodology for the management of atrial fibrillation (AF) is rhythm control, but this is sometimes very hard to accomplish. For such actions, complete isolation of all pulmonary veins (PVI) is currently widely accepted as the best endpoint. Case Presentation: In this case, we report a female patient, 81 years old, with controlled hypertension, without coronary artery disease, bearer of bilateral knee replacement, and dual chamber pacemaker implanted 1.5 years ago owing to sinus node disease, presenting the following symptoms: presyncope episodes associated with sustained irregular palpitation tachycardia. The evaluation of the pacemaker-recorded episodes of atrial fibrillation, the echocardiogram-presented normal systolic function and measurements, as well as the resting myocardial scintigraphy and with drug use did not demonstrate ischemia and/or fibrosis. The patient was in use of valsartan 320 mg daily, amlodipine 10 mg daily, sotalol hydrochloride 120 mg 2 times daily, and dabigatran 110 mg 2 times daily. At the end of the PVI, the patient presented hemodynamic instability, with a decrease in heart rate to 30 bpm and invasive arterial blood pressure to 60/30 mmHg. The pericardial puncture was quickly carried out with the possibility of cardiac tamponade as the first hypothesis, but no pericardial effusion was found. Next, we detected acute capture loss from the ventricular pacemaker lead, unvarying with high voltage and pulse width, even with stable impedance, sense and keeping the same position visualized by fluoroscopy. And there was soon afterwards induction of sustained ventricular tachycardia degenerating to spontaneous ventricular fibrillation. Electrical cardioversion-defibrillation was performed with 200J, and the sinus rhythm was reestablished, but there was a dead short, and the pacemaker generator was burned and

Semiconductor measurement technology: reliability technology for cardiac pacemakers 2: a workshop report, 1976

International Nuclear Information System (INIS)

Schafft, H.A.

1977-01-01

Summaries are presented of 12 invited talks on the following topics: the procurement and assurance of high reliability electronic parts, leak rate and moisture measurements, pacemaker batteries, and pacemaker leads. The workshop, second in a series, was held in response to strong interest expressed by the pacemaker community to address technical questions relevant to the enhancement and assurance of cardiac pacemaker reliability. Discussed at the workshop were a process validation wafer concept for assuring process uniformity in device chips; screen tests for assuring reliable electronic parts; reliability prediction; reliability comparison of semiconductor technologies; mechanisms of short-circuiting dendritic growths; details of helium and radioisotope leak test methods; a study to correlate package leak rates, as measured with test gasses, and actual moisture infusion; battery life prediction; microcalorimetric measurements to nondestructively evaluate batteries for pacemakers; and an engineer's and a physician's view of the present status of pacemaker leads. References are included with most of the reports

Risk factors for suicide among children and youths with bipolar spectrum and early bipolar disorder.

Science.gov (United States)

Rajewska-Rager, Aleksandra; Sibilski, Piotr; Lepczyńska, Natalia

2015-01-01

In recent years much attention has been given to determine risk factors for suicide among adults with bipolar disorder. Such studies concerning children and youths, which would also take into account the specificity of the developmental age, are still too few. The ability to identify risk factors for children and youths with mood disorders, as well as the possibility to monitor them, is an essential element in preventing suicidal behaviours. Previous studies have clearly indicated that in the group of patients with an early onset of the bipolar disorder the occurrence of suicidal thoughts and intentions were significantly increased. Identifying the risk of suicide is hindered further by the complexity of the phenomenon, which is a compound interaction of various factors: biological, environmental, sociological, psychological and clinical. This is especially true with young adults suffering from mental illness and presenting a number of other psychopathological symptoms. The following paper introduces and reviews the results of current studies, which analysed the risk factors for suicide among children and youths with bipolar spectrum or already diagnosed with bipolar disorder. For this purpose we conducted the overview of recent years literature available in PubMed/MEDLINE database, including the following search criteria: early onset bipolar disorder, bipolar disorder in children and young people, the spectrum of bipolar disorder, and suicidal ideation, suicidal intent, suicide.

A fully implantable pacemaker for the mouse: from battery to wireless power.

Science.gov (United States)

Laughner, Jacob I; Marrus, Scott B; Zellmer, Erik R; Weinheimer, Carla J; MacEwan, Matthew R; Cui, Sophia X; Nerbonne, Jeanne M; Efimov, Igor R

2013-01-01

Animal models have become a popular platform for the investigation of the molecular and systemic mechanisms of pathological cardiovascular physiology. Chronic pacing studies with implantable pacemakers in large animals have led to useful models of heart failure and atrial fibrillation. Unfortunately, molecular and genetic studies in these large animal models are often prohibitively expensive or not available. Conversely, the mouse is an excellent species for studying molecular mechanisms of cardiovascular disease through genetic engineering. However, the large size of available pacemakers does not lend itself to chronic pacing in mice. Here, we present the design for a novel, fully implantable wireless-powered pacemaker for mice capable of long-term (>30 days) pacing. This design is compared to a traditional battery-powered pacemaker to demonstrate critical advantages achieved through wireless inductive power transfer and control. Battery-powered and wireless-powered pacemakers were fabricated from standard electronic components in our laboratory. Mice (n = 24) were implanted with endocardial, battery-powered devices (n = 14) and epicardial, wireless-powered devices (n = 10). Wireless-powered devices were associated with reduced implant mortality and more reliable device function compared to battery-powered devices. Eight of 14 (57.1%) mice implanted with battery-powered pacemakers died following device implantation compared to 1 of 10 (10%) mice implanted with wireless-powered pacemakers. Moreover, device function was achieved for 30 days with the wireless-powered device compared to 6 days with the battery-powered device. The wireless-powered pacemaker system presented herein will allow electrophysiology studies in numerous genetically engineered mouse models as well as rapid pacing-induced heart failure and atrial arrhythmia in mice.

A Fully Implantable Pacemaker for the Mouse: From Battery to Wireless Power

Science.gov (United States)

Zellmer, Erik R.; Weinheimer, Carla J.; MacEwan, Matthew R.; Cui, Sophia X.; Nerbonne, Jeanne M.; Efimov, Igor R.

2013-01-01

Animal models have become a popular platform for the investigation of the molecular and systemic mechanisms of pathological cardiovascular physiology. Chronic pacing studies with implantable pacemakers in large animals have led to useful models of heart failure and atrial fibrillation. Unfortunately, molecular and genetic studies in these large animal models are often prohibitively expensive or not available. Conversely, the mouse is an excellent species for studying molecular mechanisms of cardiovascular disease through genetic engineering. However, the large size of available pacemakers does not lend itself to chronic pacing in mice. Here, we present the design for a novel, fully implantable wireless-powered pacemaker for mice capable of long-term (>30 days) pacing. This design is compared to a traditional battery-powered pacemaker to demonstrate critical advantages achieved through wireless inductive power transfer and control. Battery-powered and wireless-powered pacemakers were fabricated from standard electronic components in our laboratory. Mice (n = 24) were implanted with endocardial, battery-powered devices (n = 14) and epicardial, wireless-powered devices (n = 10). Wireless-powered devices were associated with reduced implant mortality and more reliable device function compared to battery-powered devices. Eight of 14 (57.1%) mice implanted with battery-powered pacemakers died following device implantation compared to 1 of 10 (10%) mice implanted with wireless-powered pacemakers. Moreover, device function was achieved for 30 days with the wireless-powered device compared to 6 days with the battery-powered device. The wireless-powered pacemaker system presented herein will allow electrophysiology studies in numerous genetically engineered mouse models as well as rapid pacing-induced heart failure and atrial arrhythmia in mice. PMID:24194832

A fully implantable pacemaker for the mouse: from battery to wireless power.

Directory of Open Access Journals (Sweden)

Jacob I Laughner

Full Text Available Animal models have become a popular platform for the investigation of the molecular and systemic mechanisms of pathological cardiovascular physiology. Chronic pacing studies with implantable pacemakers in large animals have led to useful models of heart failure and atrial fibrillation. Unfortunately, molecular and genetic studies in these large animal models are often prohibitively expensive or not available. Conversely, the mouse is an excellent species for studying molecular mechanisms of cardiovascular disease through genetic engineering. However, the large size of available pacemakers does not lend itself to chronic pacing in mice. Here, we present the design for a novel, fully implantable wireless-powered pacemaker for mice capable of long-term (>30 days pacing. This design is compared to a traditional battery-powered pacemaker to demonstrate critical advantages achieved through wireless inductive power transfer and control. Battery-powered and wireless-powered pacemakers were fabricated from standard electronic components in our laboratory. Mice (n = 24 were implanted with endocardial, battery-powered devices (n = 14 and epicardial, wireless-powered devices (n = 10. Wireless-powered devices were associated with reduced implant mortality and more reliable device function compared to battery-powered devices. Eight of 14 (57.1% mice implanted with battery-powered pacemakers died following device implantation compared to 1 of 10 (10% mice implanted with wireless-powered pacemakers. Moreover, device function was achieved for 30 days with the wireless-powered device compared to 6 days with the battery-powered device. The wireless-powered pacemaker system presented herein will allow electrophysiology studies in numerous genetically engineered mouse models as well as rapid pacing-induced heart failure and atrial arrhythmia in mice.

Parasitic bipolar amplification in a single event transient and its temperature dependence

International Nuclear Information System (INIS)

Liu Zheng; Chen Shu-Ming; Chen Jian-Jun; Qin Jun-Rui; Liu Rong-Rong

2012-01-01

Using three-dimensional technology computer-aided design (TCAD) simulation, parasitic bipolar amplification in a single event transient (SET) current of a single transistor and its temperature dependence are studied. We quantify the contributions of different current components in a SET current pulse, and it is found that the proportion of parasitic bipolar amplification in total collected charge is about 30% in both 130-nm and 90-nm technologies. The temperature dependence of parasitic bipolar amplification and the mechanism of the SET pulse are also investigated and quantified. The results show that the proportion of charge induced by parasitic bipolar increases with rising temperature, which illustrates that the parasitic bipolar amplification plays an important role in the charge collection of a single transistor

Safety of Laser Interstitial Thermal Therapy in Patients With Pacemakers.

Science.gov (United States)

Grewal, Sanjeet S; Gorny, Krzysztof R; Favazza, Christopher P; Watson, Robert E; Kaufmann, Timothy J; Van Gompel, Jamie J

2018-02-10

Laser interstitial thermal therapy (LiTT) has increasingly been used as a treatment option for medically refractory epilepsy, tumors, and radiation necrosis. The use of LiTT requires intraoperative magnetic resonance (MR) thermography. This can become an issue in patients with other implanted therapeutic devices such as pacemakers and vagal nerve stimulators due to concerns regarding increases in the specific absorption rate (SAR). This is a technical case report demonstrating a successfully and safely performed LiTT in a 1.5-T magnetic resonance imaging (MRI) in a patient with a pacemaker for mesial temporal sclerosis. An 83-yr-old gentleman who had an implanted cardiac pacemaker presented with medically intractable epilepsy and was confirmed to have mesial temporal sclerosis on imaging. Video electroencephalography demonstrated concordant ipsilateral seizures and semiology. He underwent LiTT for ablation of the mesial temporal lobe. This was performed with the below described protocol with a cardiology nurse monitoring the patient's cardiac condition and a physicist monitoring SAR, and MR imaging quality without any adverse events. This study reports on a protocol of cardiac and MR SAR to safely perform MR-guided LiTT in the setting of traditional pacemakers in patients who are not pacemaker dependent. Copyright © 2018 by the Congress of Neurological Surgeons

Integrated Neurobiology of Bipolar Disorder

Science.gov (United States)

Maletic, Vladimir; Raison, Charles

2014-01-01

From a neurobiological perspective there is no such thing as bipolar disorder. Rather, it is almost certainly the case that many somewhat similar, but subtly different, pathological conditions produce a disease state that we currently diagnose as bipolarity. This heterogeneity – reflected in the lack of synergy between our current diagnostic schema and our rapidly advancing scientific understanding of the condition – limits attempts to articulate an integrated perspective on bipolar disorder. However, despite these challenges, scientific findings in recent years are beginning to offer a provisional “unified field theory” of the disease. This theory sees bipolar disorder as a suite of related neurodevelopmental conditions with interconnected functional abnormalities that often appear early in life and worsen over time. In addition to accelerated loss of volume in brain areas known to be essential for mood regulation and cognitive function, consistent findings have emerged at a cellular level, providing evidence that bipolar disorder is reliably associated with dysregulation of glial–neuronal interactions. Among these glial elements are microglia – the brain’s primary immune elements, which appear to be overactive in the context of bipolarity. Multiple studies now indicate that inflammation is also increased in the periphery of the body in both the depressive and manic phases of the illness, with at least some return to normality in the euthymic state. These findings are consistent with changes in the hypothalamic–pituitary–adrenal axis, which are known to drive inflammatory activation. In summary, the very fact that no single gene, pathway, or brain abnormality is likely to ever account for the condition is itself an extremely important first step in better articulating an integrated perspective on both its ontological status and pathogenesis. Whether this perspective will translate into the discovery of innumerable more homogeneous forms of

Maximizing ion current rectification in a bipolar conical nanopore fluidic diode using optimum junction location.

Science.gov (United States)

Singh, Kunwar Pal

2016-10-12

The ion current rectification has been obtained as a function of the location of a heterojunction in a bipolar conical nanopore fluidic diode for different parameters to determine the junction location for maximum ion current rectification using numerical simulations. Forward current peaks for a specific location of the junction and reverse current decreases with the junction location due to a change in ion enrichment/depletion in the pore. The optimum location of the heterojunction shifts towards the tip with base/tip diameter and surface charge density, and towards the base with the electrolyte concentration. The optimum location of the heterojunction has been approximated by an equation as a function of pore length, base/tip diameter, surface charge density and electrolyte concentration. The study is useful to design a rectifier with maximum ion current rectification for practical purposes.

Permanent pacemaker lead induced severe tricuspid regurgitation in patient undergoing multiple valve surgery.

Science.gov (United States)

Lee, Jung Hee; Kim, Tae Ho; Kim, Wook Sung

2015-04-01

Severe and permanent tricuspid regurgitation induced by pacemaker leads is rarely reported in the literature. The mechanism of pacemaker-induced tricuspid regurgitation has been identified, but its management has not been well established. Furthermore, debate still exists regarding the proper surgical approach. We present the case of a patient with severe tricuspid regurgitation induced by a pacemaker lead, accompanied by triple valve disease. The patient underwent double valve replacement and tricuspid valve repair without removal of the pre-existing pacemaker lead. The operation was successful and the surgical procedure is discussed in detail.

Twiddler-syndrom er en årsag til pacemaker elektrode displacering

DEFF Research Database (Denmark)

Grønbech, Keea Treu; Hansen, Michael Gilså

2013-01-01

Twiddler's syndrome is a rare cause of pacemaker electrode displacement. The displacement is caused by the patient's manipulation with the pacemaker, so the electrode is retracted. We describe a case of a 79-year-old overweight woman with a known psychiatric anamnesis, who was admitted twice...

Pacemaker lead perforation of the right ventricle associated with Moraxella phenylpyruvica infection in a dog.

Science.gov (United States)

Ciavarella, A; Nimmo, J; Hambrook, L

2016-04-01

A 13-year-old neutered male Border Collie was presented with acute onset syncope, weakness and anorexia 10 months after transvenous pacemaker implantation. The patient was laterally recumbent, bradycardic (36 beats/min) and febrile (40.7°C) on presentation. An electrocardiogram (ECG) revealed recurrence of third-degree atrioventricular block with a ventricular escape rhythm. Fluoroscopy identified migration of the pacemaker tip through the apex of the right ventricle. Echocardiography failed to reveal any evidence of pericardial effusion or cardiac tamponade. Full postmortem was performed after euthanasia. The pacemaker lead had perforated the apex of the right ventricle and lodged in the right pleural space. Culture of blood (taken antemortem), pericardial sac, right ventricular wall (surrounding pacemaker lead), pacemaker lead tip and pericardial fluid revealed a pure growth of Moraxella phenylpyruvica. Bacteraemia associated with M. phenylpyruvica has never been reported in the dog, but sporadic cases are reported in humans. Infection could have resulted from either pre-existing myocarditis or opportunistic infection and bacteraemia post pacemaker implantation. Evaluation of the pacemaker function at regular intervals would allow early detection of poor pacemaker-to-myocardium contact, which would prompt further investigation of pacemaker lead abnormalities such as perforation. © 2016 Australian Veterinary Association.

Nickel hydrogen bipolar battery electrode design

Science.gov (United States)

Puglisi, V. J.; Russell, P.; Verrier, D.; Hall, A.

1985-01-01

The preferred approach of the NASA development effort in nickel hydrogen battery design utilizes a bipolar plate stacking arrangement to obtain the required voltage-capacity configuration. In a bipolar stack, component designs must take into account not only the typical design considerations such as voltage, capacity and gas management, but also conductivity to the bipolar (i.e., intercell) plate. The nickel and hydrogen electrode development specifically relevant to bipolar cell operation is discussed. Nickel oxide electrodes, having variable type grids and in thicknesses up to .085 inch are being fabricated and characterized to provide a data base. A selection will be made based upon a system level tradeoff. Negative (hydrpogen) electrodes are being screened to select a high performance electrode which can function as a bipolar electrode. Present nickel hydrogen negative electrodes are not capable of conducting current through their cross-section. An electrode was tested which exhibits low charge and discharge polarization voltages and at the same time is conductive. Test data is presented.

High rate lithium-thionyl chloride bipolar battery development

Energy Technology Data Exchange (ETDEWEB)

Russell, P.G.; Goebel, F. [Yardney Technical Products, Inc., Pawcatuck, CT (United States)

1994-12-31

The lithium/thionyl chloride system is capable of providing both high power and high energy density when cells containing thin components are arranged in a bipolar configuration. Electrode current densities in excess of 300mA/cm{sup 2} are achieved during pulse discharge. The present work is concerned with bipolar cell design, cathode evaluation, component manufacturing methods, and the assembly and testing of bipolar modules containing up to 150 cells.

Leadless cardiac pacemakers: present and the future.

Science.gov (United States)

Chew, Derek S; Kuriachan, Vikas

2018-01-01

Pacing technology for many decades has been composed of a generator attached to leads that are usually transvenous. Recently, leadless pacemakers have been studied in clinical settings and now available for use in many countries. This includes the single-component Nanostim Leadless Cardiac Pacemaker and Micra Transcatheter Pacing System, as well as the multicomponent Wireless Stimulation Endocardial system. Clinical studies in single-component leadless pacing technology has shown that they can be successfully implanted with minimal complications. The follow-up studies also seem to confirm the findings from the initial clinical trials. These systems offer some advantages over a traditional pacing system comprised of a subcutaneous generator and transvenous leads. In many ways, these leadless systems are disruptive technologies that are changing the traditional pacemaker concept and preferred for some patients. Ongoing research is needed to better assess their long-term function, safety, and end-of-life strategies. In the future, multichamber leadless pacing is expected to be developed and perhaps obviating the need for transvenous leads and their associated complications.

Conceptual design of GaN betavoltaic battery using in cardiac pacemaker

International Nuclear Information System (INIS)

Mohamadian, M.; Feghhi, S.A. H.; Afarideh, H.

2007-01-01

Introduction: Pacemaker is an electronic biomedical device which stimulates and regulates or amplify the human heartbeat by delivering weak electrical pulses to the cardiac muscle at regular intervals when its natural regulating mechanisms break down. Developments in design and implementation of power source in adjacent to advances in electronic circuitry is an important aspect in optimization of pacemakers. For instance, many implant patients continue to outlive their batteries and require costly and risky replacement surgery. So such device needs to have high energy density power source and maintain a stable current and voltage for a long period of time to avoid frequent replacements. In addition, the size is also an important consideration for implantable batteries. Betavoltaic batteries are being researched as a suitable source for these applications. Also, these batteries have vast application in which the replacement of batteries is highly inconvenient, such as in oil and mining industries, which often place sensors in dangerous or hard-to-reach locations. The purpose of the present investigation is determination of the optimal parameters of low energy GaN betavoltaic battery in artificial cardiac pacemakers using MCNP code which have higher efficiency than those available with previous devices, especially thermoelectric converters (∼15%). Material and Methods: In this design, two p-n diode structures from GaN semiconductor were used to collect the charge from a layer of 6 3Ni as a source which is centered between the two p-n junctions. MCNP simulation results have been used to determine the amount of electron current from interaction of beta particles in p-n junctions. Results and Discussion: Calculation results indicate that the short circuit current, open circuit voltage and efficiency of a single device are 1.1 μA/cm 2 , 2.7 volt and 25%, respectively. Also, it's concluded that with suitable arrangement of these single devices, one could construct a

Permanent Pacemaker Lead Induced Severe Tricuspid Regurgitation in Patient Undergoing Multiple Valve Surgery

Directory of Open Access Journals (Sweden)

Jung Hee Lee

2015-04-01

Full Text Available Severe and permanent tricuspid regurgitation induced by pacemaker leads is rarely reported in the literature. The mechanism of pacemaker-induced tricuspid regurgitation has been identified, but its management has not been well established. Furthermore, debate still exists regarding the proper surgical approach. We present the case of a patient with severe tricuspid regurgitation induced by a pacemaker lead, accompanied by triple valve disease. The patient underwent double valve replacement and tricuspid valve repair without removal of the pre-existing pacemaker lead. The operation was successful and the surgical procedure is discussed in detail.

Implantable Cardiac Pacemakers – 50 Years from the First Implantation

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Ratko Magjarević

2010-01-01

Overview: Development of implantable cardiac pacemaker was enabled by another important invention, the silicon transistor. h ough the invention of suitable lithium cells as appropriate power supply was essential for prolongation of battery life cycle and for increased reliability of pacemakers, main milestones in the development were associated with technological breakthroughs in electronics: from transistors, which introduced such features as small size and low power consumption, to hybrid and integrated circuits, which enabled programmability, microprocessors, which added more options in programming (multiprogrammability, diagnostics and telemetry, and the ICT (information communication technology that enabled physicians remote access to patients and interrogation of their implantable devices. Conclusions: Implantable pacemakers are reliable devices indicated for a wide range of dif erent therapies of cardiac rhythm disorders and heart failure. h ere is still a lot to learn about the physiology of a normal heart and even more about the failing heart. Modern pacemakers provide physicians valuable information from pacemakers’ memory via the built-in telemetry system. h ese information help physicians to better understand pathologic processes within the heart, thus contributing to the development of new ideas for treatment of diseases and for precise tailoring of the therapy to the patient’s needs. Although implantable pacemakers have reached the level of mature technology, they will continue to develop with therapies and diagnostics to facilitate a higher quality of life.

[Pediatric bipolar disorder - case report of a bipolar patient with disease onset in childhood and adolescence: implications for diagnosis and therapy].

Science.gov (United States)

Lackner, N; Birner, A; Bengesser, S A; Reininghaus, B; Kapfhammer, H P; Reininghaus, E

2014-11-01

In recent years, intense controversies have evolved about the existence and exact diagnostic criteria of pediatric bipolar affective disorder. The present study aims to discuss pediatric bipolar affective disorder based on the current literature focussing on the diagnostic prospects. Based on a case study, a process of bipolar disorder developed in childhood is depicted exemplarily. Because of the high comorbidity and overlapping symptoms of paediatric bipolar affective disorder and other psychiatric disorders, the major impact of the differential diagnosis has to be stressed. An early diagnosis and the treatment possibilities are discussed. © Georg Thieme Verlag KG Stuttgart · New York.

Excitation model of pacemaker cardiomyocytes of cardiac conduction system

Science.gov (United States)

Grigoriev, M.; Babich, L.

2015-11-01

Myocardium includes typical and atypical cardiomyocytes - pacemakers, which form the cardiac conduction system. Excitation from the atrioventricular node in normal conditions is possible only in one direction. Retrograde direction of pulses is impossible. The most important prerequisite for the work of cardiomyocytes is the anatomical integrity of the conduction system. Changes in contractile force of the cardiomyocytes, which appear periodically, are due to two mechanisms of self-regulation - heterometric and homeometric. Graphic course of the excitation pulse propagation along the heart muscle more accurately reveals the understanding of the arrhythmia mechanism. These models have the ability to visualize the essence of excitation dynamics. However, they do not have the proper forecasting function for result estimation. Integrative mathematical model enables further investigation of general laws of the myocardium active behavior, allows for determination of the violation mechanism of electrical and contractile function of cardiomyocytes. Currently, there is no full understanding of the topography of pacemakers and ionic mechanisms. There is a need for the development of direction of mathematical modeling and comparative studies of the electrophysiological arrangement of cells of atrioventricular connection and ventricular conduction system.

Pacemaker lead fracture without an increase in lead impedance caused by cardiac fibroma

Directory of Open Access Journals (Sweden)

Daisuke Sato

2013-12-01

Full Text Available We report the case of a 64-year-old man who had a permanent pacemaker with a unipolar silicone electrode positioned in the right ventricle in 1989 for sinus node dysfunction. On a routine checkup in June 2011, a 28-mm-diameter mass was discovered, which appeared to adhere to the tricuspid valve and the ventricular lead. The size of the mass did not change for the next 6 months, and the lead impedance was maintained at around 500–600 Ω. Because pacing failure was observed in January 2012, he underwent an urgent pacemaker check; however, the lead impedance was found not to have increased greatly (689 Ω. Nevertheless, the pacemaker lead was noted to be fractured at the tricuspid level. His echocardiogram showed new severe tricuspid regurgitation and a floating mass around the lead. We extracted the fractured lead, enucleated the tumor, replaced the tricuspid valve, and placed an epicardial lead. Macroscopic examination revealed that the tumor surrounded the fractured lead and covered the stump. Pathological examination revealed that the tumor was composed of fibrous connective tissue. We presumed that electric current continued to flow through the stump of the fractured unipolar lead to the generator, and this might have caused the limited increase in lead impedance.

Measurement of low-frequency base and collector current noise and coherence in SiGe heterojunction bipolar transistors using transimpedance amplifiers

NARCIS (Netherlands)

Bruce, S.P.O.; Vandamme, L.K.J.; Rydberg, A.

1999-01-01

Transimpedance amplifiers have been used for direct study of current noise in silicon germanium (SiGe) heterojunction bipolar transistors (HBT's) at different biasing conditions. This has facilitated a wider range of resistances in the measurement circuit around the transistor than is possible when

A proposal for a standard communication protocol for pacemaker/ICD programmers

NARCIS (Netherlands)

Dijk, WA; Hooijschuur, CAM; van der Velde, W; Dassen, WRM

2005-01-01

The information generated by pacemakers and ICD's to support the cardiologist and technician for installing the optimal settings for the patient is increasing rapidly. In this paper a proposal is described for electronic data exchange between the pacemaker/ICD programmers and electronic information

Circadian Pacemaker – Temperature Compensation

NARCIS (Netherlands)

Gerkema, Menno P.; Binder, Marc D.; Hirokawa, Nobutaka; Windhorst, Uwe

2009-01-01

One of the defining characteristics of circadian pacemakers and indicates the independence of the speed of circadian clock processes of environmental temperature. Mechanisms involved, so far not elucidated in full detail, entail at least two processes that are similarly affected by temperature

Development of pacemaker properties and rhythmogenic mechanisms in the mouse embryonic respiratory network

Science.gov (United States)

Chevalier, Marc; Toporikova, Natalia; Simmers, John; Thoby-Brisson, Muriel

2016-01-01

Breathing is a vital rhythmic behavior generated by hindbrain neuronal circuitry, including the preBötzinger complex network (preBötC) that controls inspiration. The emergence of preBötC network activity during prenatal development has been described, but little is known regarding inspiratory neurons expressing pacemaker properties at embryonic stages. Here, we combined calcium imaging and electrophysiological recordings in mouse embryo brainstem slices together with computational modeling to reveal the existence of heterogeneous pacemaker oscillatory properties relying on distinct combinations of burst-generating INaP and ICAN conductances. The respective proportion of the different inspiratory pacemaker subtypes changes during prenatal development. Concomitantly, network rhythmogenesis switches from a purely INaP/ICAN-dependent mechanism at E16.5 to a combined pacemaker/network-driven process at E18.5. Our results provide the first description of pacemaker bursting properties in embryonic preBötC neurons and indicate that network rhythmogenesis undergoes important changes during prenatal development through alterations in both circuit properties and the biophysical characteristics of pacemaker neurons. DOI: http://dx.doi.org/10.7554/eLife.16125.001 PMID:27434668

Magnetic Resonance Imaging in a Patient with a Dual Chamber Pacemaker

Directory of Open Access Journals (Sweden)

Lynne Martina Millar

2010-01-01

Full Text Available Having a pacemaker has been seen an absolute contraindication to having an MRI scan. This has become increasingly difficult in clinical practice as insertion of pacemakers and implantable cardiac defibrillators is at an all time high. Here we outline a case where a 71-year-old male patient with a permanent pacemaker needed to have an MRI scan to ascertain the aetiology of his condition and help guide further management. Given this clinical dilemma, an emergency clinical ethics consultation was arranged. As a result the patient underwent an MRI scan safely under controlled conditions with a consultant cardiologist and radiologist present. The results of the MRI scan were then able to tailor further treatment. This case highlights that in certain conditions an MRI can be performed in patients with permanent pacemakers and outlines the role of clinical ethics committees in complex medical decision making.

Evolução do conceito e controvérsias atuais sobre o transtorno bipolar do humor Bipolar disorder: evolution of the concept and current controversies

Directory of Open Access Journals (Sweden)

José Alberto Del Porto

2004-10-01

Full Text Available O autor revê o conceito de transtorno bipolar como um processo em evolução. Suas raízes podem ser encontradas no trabalho de Araeteus da Capadócia, que assumia serem a melancolia e a mania duas formas da mesma doença. A compreensão atual da doença bipolar começou na França, através dos trabalhos de Falret (1851 e Baillarguer (1854. Os conceitos fundamentais de Kraepelin mudaram as bases da nosologia psiquiátrica, e o conceito unitário de Kraepelin sobre a insanidade maníaco-depressiva passou a ser amplamente aceito. Depois de Kraepelin, no entanto, as idéias de Kleist e Leonhard, na Alemanha, e o trabalho subseqüente de Angst, Perris e Winokur enfatizaram a distinção entre as formas monopolares e bipolares da depressão. Mais recentemente a ênfase mudou novamente para o espectro bipolar, que em suas formas leves expande-se às bordas dos temperamentos normais. Finalizando, o autor sumariza os aspectos polêmicos da nosologia da doença bipolar e seus limites com as esquizofrenias, a doença esquizoafetiva e as psicoses ciclóides.The author reviews the evolution of the concept of bipolar disorder as an ongoing process. Its roots can be found in the work of Araeteus of Capadocia, who assumed that melancholia and mania were two forms of the same disease. The modern understanding of bipolar disorder began in France, through the work of Falret (1851 and Baillarger (1854. The pivotal concepts of Emil Kraepelin changed the basis of psychiatric nosology, and Kraepelin's unitary concept of manic-depressive insanity was largely accepted. Kraepelin and Weigandt's ideas on mixed states were the cornerstone of this unitary concept. After Kraepelin, however, the ideas of Kleist and Leonhard, in Germany, as well as the work of Angst, Perris and Winokur, emphasized the distinction between unipolar and bipolar forms of depression. More recently, the emphasis has shifted again to the bipolar spectrum, which, in its mild forms, expanded to the

Zebrafish heart as a model to study the integrative autonomic control of pacemaker function

Science.gov (United States)

Stoyek, Matthew R.; Quinn, T. Alexander; Croll, Roger P.

2016-01-01

The cardiac pacemaker sets the heart's primary rate, with pacemaker discharge controlled by the autonomic nervous system through intracardiac ganglia. A fundamental issue in understanding the relationship between neural activity and cardiac chronotropy is the identification of neuronal populations that control pacemaker cells. To date, most studies of neurocardiac control have been done in mammalian species, where neurons are embedded in and distributed throughout the heart, so they are largely inaccessible for whole-organ, integrative studies. Here, we establish the isolated, innervated zebrafish heart as a novel alternative model for studies of autonomic control of heart rate. Stimulation of individual cardiac vagosympathetic nerve trunks evoked bradycardia (parasympathetic activation) and tachycardia (sympathetic activation). Simultaneous stimulation of both vagosympathetic nerve trunks evoked a summative effect. Effects of nerve stimulation were mimicked by direct application of cholinergic and adrenergic agents. Optical mapping of electrical activity confirmed the sinoatrial region as the site of origin of normal pacemaker activity and identified a secondary pacemaker in the atrioventricular region. Strong vagosympathetic nerve stimulation resulted in a shift in the origin of initial excitation from the sinoatrial pacemaker to the atrioventricular pacemaker. Putative pacemaker cells in the sinoatrial and atrioventricular regions expressed adrenergic β2 and cholinergic muscarinic type 2 receptors. Collectively, we have demonstrated that the zebrafish heart contains the accepted hallmarks of vertebrate cardiac control, establishing this preparation as a viable model for studies of integrative physiological control of cardiac function by intracardiac neurons. PMID:27342878

Devices That May Interfere with Pacemakers

Science.gov (United States)

... Communications Commission (FCC) makes new frequencies available. Newer cellphones using these new frequencies might make pacemakers less reliable. A group of cellphone companies is studying that possibility. Bluetooth® headsets do ...

Bipolar disorder: an update | Outhoff | South African Family Practice

African Journals Online (AJOL)

Bipolar disorder, characterised by alternating discrete episodes of (hypo)mania and depression, provides unique diagnostic and treatment challenges. Updated diagnostic (DSM-5) and current pharmacological treatment recommendations are briefly reviewed here. Keywords: bipolar disorder; diagnosis; evidence-based ...

Early Performance and Safety of the Micra Transcatheter Pacemaker in Pigs.

Science.gov (United States)

Bonner, Matthew; Eggen, Michael; Haddad, Tarek; Sheldon, Todd; Williams, Eric

2015-11-01

The Micra® Transcatheter Pacing System (TPS; Medtronic Inc., Minneapolis, MN, USA) is a miniaturized single-chamber pacemaker system that is delivered via catheter through the femoral vein. In this study, the electrical performance was compared between the TPS and a traditional leaded pacemaker. In addition, the safety profile of the two systems was compared by thorough monitoring for a number of adverse events. The TPS was implanted in the right ventricular apex of 10 Yucatan mini pigs and a Medtronic single-lead pacemaker (SLP) was implanted in the right ventricular apex of another 10 pigs and connected to a traditional pacemaker. The electrical performance of all devices was monitored for 12 weeks. The safety profile of each system was characterized using x-ray, computed tomography, ultrasound, blood work, and necropsy to monitor for a variety of adverse events. At implant the mean pacing thresholds were 0.58 ± 0.17 V @0.24 ms and 0.75 ± 0.29 V @0.21 ms for the TPS and the SLP respectively. After 12 weeks, mean thresholds were 0.94 ± 0.46 V and 1.85 ± 0.75 V (P pacemaker system. © 2015 Medtronic PLC. Pacing and Clinical Electrophysiology published by Wiley Periodicals, Inc.

Assessing and addressing cognitive impairment in bipolar disorder

DEFF Research Database (Denmark)

Miskowiak, K W; Burdick, K E; Martinez-Aran, A

2018-01-01

OBJECTIVES: Cognition is a new treatment target to aid functional recovery and enhance quality of life for patients with bipolar disorder. The International Society for Bipolar Disorders (ISBD) Targeting Cognition Task Force aimed to develop consensus-based clinical recommendations on whether, when...... in Bipolar Disorder Rating Assessment, and (III) evaluate the impact of medication and comorbidity, refer patients for comprehensive neuropsychological evaluation when clinically indicated, and encourage patients to build cognitive reserve. Regarding question (IV), there is limited evidence for current...

Dragoljub (Bata Adamov (1927-1996: The first pacemaker implantation in Serbia

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Pavlović Siniša U.

2017-01-01

Full Text Available It has been over half a century since the implementation of pacemaker therapy in our country and the region. The first successful implantation of a pacemaker in former Yugoslavia and in Serbia took place on September 16, 1965 in “Dr. Dragiša Mišović” Clinical Hospital Centre, and this operation, with a team of doctors of the institution, was performed by surgeon Dragoljub (Bata Adamov (1927–1996. The first permanent pacemaker implantation was with epicardial leads with thoracotomy approach. The patient was operated on under general anesthesia, administered by anesthesiologist Predrag Lalević (1927–, and Dr. Adamov was assisted by Dr. Miša Albrecht (1933– and Dr. Milan Dragović (1933–2009. Although pacemaker therapy has since been widely proven and confirmed, it is necessary to remember the pioneers who introduced this kind of therapy to the region, as they deserve a distinguished place in the history of medicine in Serbia.

A leadless pacemaker in the real-world setting

DEFF Research Database (Denmark)

Roberts, Paul R.; Clementy, Nicolas; Al Samadi, Faisal

2017-01-01

, telemetry, and battery issues. Objective The acute performance of the Micra transcatheter pacemaker from a worldwide Post-Approval Registry is reported. Methods The registry is an ongoing prospective single-arm observational study designed to assess the safety and effectiveness of Micra in the post...... were low and stable. Conclusion Performance of the Micra transcatheter pacemaker in a real-world setting demonstrates a high rate (99.6%) of implant success and low rate (1.51%) of major complications through 30 days post implant. In particular, the rates of pericardial effusion, device dislodgement...

Add-on treatment with N-acetylcysteine for bipolar depression

DEFF Research Database (Denmark)

Ellegaard, Pernille Kempel; Licht, Rasmus Wentzer; Poulsen, Henrik Enghusen

2018-01-01

BACKGROUND: Oxidative stress and inflammation may be involved in the development and progression of mood disorders, including bipolar disorder. Currently, there is a scarcity of useful treatment options for bipolar depressive episodes, especially compared with the efficacy of treatment for acute ...

Atrioventricular Pacemaker Lead Reversal

Directory of Open Access Journals (Sweden)

Mehmet K Aktas, MD

2007-01-01

Full Text Available During cardiac surgery temporary epicardial atrial and ventricular leads are placed in case cardiac pacing is required postoperatively. We present the first reported series of patients with reversal of atrioventricular electrodes in the temporary pacemaker without any consequent deleterious hemodynamic effect. We review the electrocardiographic findings and discuss the findings that lead to the discovery of atrioventricular lead reversal.

Dual chamber pacemaker implants - a new opportunity in Pakistan for children with congenital and acquired complete heart block

International Nuclear Information System (INIS)

Ashfaq, A.; Khan, M.A.; Atiq, M.

2011-01-01

Implantation of cardiac pacemakers has been practiced for at least five decades with continuous developments of the hardware. The invention of dual chamber pacemakers has initiated a debate concerning its superiority over single chamber ventricular pacemakers. Throughout the world, surgeons have been using dual chambered permanent pacemakers with successful follow ups. However, Pakistan has not yet taken the advantage of such pacemaker devices till now. We report three cases that underwent a dual chamber permanent pacemaker implantation for the first time in children less than 8 kg with successful follow ups. (author)

A Functional Analysis of Circadian Pacemakers in Nocturnal Rodents. IV. Entrainment : Pacemaker as Clock

NARCIS (Netherlands)

Pittendrigh, Colin S.; Daan, Serge

1976-01-01

1. In the first part of the paper, the model of non-parametric entrainment of circadian pacemakers is tested for the case of nocturnal rodents. The model makes use of the available data on freerunning period (τ) in constant darkness and on phase response curves (PRC) for short light pulses. It is

Echocardiography-guided Radiofrequency Catheter Ablation of Atrioventricular Node and VVI Pacemaker Implantation

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T Guo

2014-05-01

Full Text Available Objective: This study is to evaluate the feasibility and safety of intracardiac radiofrequency catheter ablation (RFCA of the atrioventricular node (AVN and pacemaker implantation using transthoracic echocardiography. Methods: Eleven patients – six males and five females (mean age 66 years – with persistent or permanent atrial fibrillation/atrial flutter received RFCA of AVN and VVI pacemaker implantation (paces and senses the ventricle and is inhibited if it senses ventricular activity. Under transthoracic echocardiography, the electrode catheters were positioned intracardiac, and target ablation was performed, with the permanent pacemaking catheter in the left subclavian vein and the ablation catheter in the right femoral vein. The multi-view imaging and dynamic observation applied during the stable AV dissociation were successful. Results: Atrioventricular node ablation and permanent pacemaker implantation in 11 patients were completed successfully without X-ray exposure. The operation success rate was 100%. All patients recovered well within the follow-up period. Conclusions: Radiofrequency catheter ablation of AVN and VVI pacemaker implantation under transthoracic echocardiography guidance is a safe, easy and feasible approach. This procedure could be an important supplemental measure to catheter ablation of arrhythmia under routine X-ray fluoroscopy.

Sikkerhed af magnetisk resonans-skanning hos patienter med pacemaker og implanterbar defibrillator

DEFF Research Database (Denmark)

Al-Sabagh, Kifah Hekmat; Christensen, Britta Ege; Thøgersen, Anna Margrethe

2010-01-01

INTRODUCTION: The presence of a cardiac implantable device is ICD considered an absolute contraindication to magnetic resonance imaging (MRI). The purpose of this study was to evaluate the safety of performing MRI in patients with cardiac pacemakers and ICDs that had a compelling clinical need...... for MRI examination. MATERIAL AND METHODS: During a period of nine years we have included 65 patients with cardiac devices (60 pacemakers and five ICDs) who underwent a total of 73 MRI examinations at 1.5 T. All pacemakers were reprogrammed before MRI to asynchronous mode to avoid MRI-induced inhibition...... safely in 63 patients. Inhibition of pacemaker output was observed in one patient and induction of ventricular fibrillation was observed in another with ICD. A significant increase in PCT was rare and only detected in 1% of all electrodes. CONCLUSION: MRI can be performed safely in patients...

Leadless Cardiac Pacemaker Implantation After Lead Extraction in Patients With Severe Device Infection.

Science.gov (United States)

Kypta, Alexander; Blessberger, Hermann; Kammler, Juergen; Lambert, Thomas; Lichtenauer, Michael; Brandstaetter, Walter; Gabriel, Michael; Steinwender, Clemens

2016-09-01

Conventional pacemaker therapy is limited by short- and long-term complications, most notably device infection. Transcatheter pacing systems (TPS) may be beneficial in this kind of patients as they eliminate the need for a device pocket and leads and thus may reduce the risk of re-infection. We assessed a novel procedure in 6 patients with severe device infection who were pacemaker dependent. After lead extraction a single chamber TPS was implanted into the right ventricle. Of the 6 patients who underwent lead extraction due to severe device infection at our institution, 3 were diagnosed with a pocket infection only, whereas the other 3 showed symptoms of both pocket and lead infection. Successful lead extraction and TPS implantation was accomplished in all patients. Four patients were bridged with a temporary pacemaker between 2 hours and 2 days after lead extraction, whereas 2 patients had the TPS implanted during the same procedure just before traditional pacemaker system removal. All patients stayed free of infection during the follow-up period of 12 weeks. An additional positron emission tomography scan was performed in each patient and indicated no signs of an infection around the TPS. Transcather pacemaker implantation was safe and feasible in 6 patients and did not result in re-infection even if implanted before removal of the infected pacemaker system within the same procedure. Therefore, implantation of a TPS may be an option for patients with severe device infection, especially in those with blocked venous access or who are pacemaker dependent. © 2016 Wiley Periodicals, Inc.

Pacemakers in patients with familial dysautonomia--a review of experience with 20 patients.

Science.gov (United States)

Gold-von Simson, Gabrielle; Rutkowski, Monika; Berlin, Dena; Axelrod, Felicia B

2005-02-01

Familial dysautonomia (FD) is a genetic disease associated with a high incidence of sudden death. If fatal bradyarrhythmia is an etiological factor then the incidence of sudden death should decrease after pacemaker placement. Retrospective review of 596 registered FD patients revealed that 22 FD patients (3.7%) had pacemakers placed between December 1984 and June 2003. Clinical and electrocardiographic indications for placement and demographic data were assessed for 20 of the 22 patients (10 males, 10 females, ages 4 to 48 years). Two patients were excluded because of insufficient data. Prior to pacemaker placement, presenting symptoms were syncope and cardiac arrest, 16/20 (80%) and 6/20 (30 %), respectively. Asystole was the most frequent electrocardiographic finding and was documented in 17/20 patients (85 %). Other electrocardiographic abnormalities included bradycardia, AV block, prolonged QTc and prolonged JTc. The average duration of pacemaker utilization was 5.7 years (range 5 months to 14.5 years). Complications included infection (1 patient) and wire migration (2 patients). In the one patient with infection, the pacemaker was permanently removed. This patient then experienced multiple syncopal episodes and death. There were 7 other deaths. Three deaths occurred suddenly without preceding events, and 4 patients had non-cardiac causes of death. None of these 7 deceased patients had recurrence of syncope after pacemaker placement. In the 12 surviving patients, 6 had recurrence of syncope but none had cardiac arrest. Pacemaker placement may protect FD patients from fatal bradyarrhythmia and may decrease the incidence of syncope. However, data are limited and prospective analysis is needed.

Elektrokirurgi hos patienter med pacemaker og implanterbar kardioverter-defibrillator

DEFF Research Database (Denmark)

Lønnberg, Ann Sophie Claire; Philberts, Berit Thornvig; Bonde, Christian

2017-01-01

Electrosurgery is a very useful tool and one of the most commonly used techniques. However, the technique can interfere with pacemakers and implantable cardioverter defibrillators. This article provides practical recommendations for the use of electrosurgery in these patients.......Electrosurgery is a very useful tool and one of the most commonly used techniques. However, the technique can interfere with pacemakers and implantable cardioverter defibrillators. This article provides practical recommendations for the use of electrosurgery in these patients....

Study on ionizing radiation effects of bipolar transistor with BPSG films

International Nuclear Information System (INIS)

Lu Man; Zhang Xiaoling; Xie Xuesong; Sun Jiangchao; Wang Pengpeng; Lu Changzhi; Zhang Yanxiu

2013-01-01

Background: Because of the damage induced by ionizing radiation, bipolar transistors in integrated voltage regulator could induce the current gain degradation and increase leakage current. This will bring serious problems to electronic system. Purpose: In order to ensure the reliability of the device work in the radiation environments, the device irradiation reinforcement technology is used. Methods: The characteristics of 60 Co γ irradiation and annealing at different temperatures in bipolar transistors and voltage regulators (JW117) with different passive films for SiO 2 +BPSG+SiO 2 and SiO 2 +SiN have been investigated. Results: The devices with BPSG film enhanced radiation tolerance significantly. Because BPSG films have better absorption for Na + in SiO 2 layer, the surface recombination rate of base region in a bipolar transistor and the excess base current have been reduced. It may be the main reason for BJT with BPSG film having a good radiation hardness. And annealing experiments at different temperatures after irradiation ensure the reliability of the devices with BPSG films. Conclusions: A method of improving the ionizing irradiation hardness of bipolar transistors is proposed. As well as the linear integrated circuits which containing bipolar transistors, an experimental basis for the anti-ionizing radiation effects of bipolar transistors is provided. (authors)

Is bipolar always bipolar? Understanding the controversy on bipolar disorder in children

Science.gov (United States)

Grimmer, Yvonne; Hohmann, Sarah

2014-01-01

Dramatically increasing prevalence rates of bipolar disorder in children and adolescents in the United States have provoked controversy regarding the boundaries of manic symptoms in child and adolescent psychiatry. The serious impact of this ongoing debate on the treatment of affected children is reflected in the concomitant increase in prescription rates for antipsychotic medication. A key question in the debate is whether this increase in bipolar disorder in children and adolescents is based on a better detection of early-onset bipolar disorder—which can present differently in children and adolescents—or whether it is caused by an incorrect assignment of symptoms which overlap with other widely known disorders. So far, most findings suggest that the suspected symptoms, in particular chronic, non-episodic irritability (a mood symptom presenting with easy annoyance, temper tantrums and anger) do not constitute a developmental presentation of childhood bipolar disorder. Additional research based on prospective, longitudinal studies is needed to further clarify the developmental trajectories of bipolar disorder and the diagnostic status of chronic, non-episodic irritability. PMID:25580265

Pacemaker System Malfunction Resulting from External Electrical Cardioversion: A Case Report

Directory of Open Access Journals (Sweden)

Taku Nishida, MD

2009-01-01

Full Text Available In May 2005 a 68-year-old woman received a VDD pacemaker implantation in the right pectoral region at our hospital for the treatment of complete atrioventricular block. In July 2008, she was diagnosed with dilated cardiomyopathy based on histological testing. In November 2008, she developed syncope due to ventricular tachycardia while at another hospital. She underwent external electrical cardioversion with an anterior-lateral paddle position using a single shock of 100 J. This shock led to severe bradycardia resulting in a transfer to our hospital. The physician who provided the shock could not have been aware that the patient had an implanted pacemaker. The skin above the pulse generator was burned. The electrocardiogram showed no pacing spikes or ventricular escape rhythm. Investigation of the pacemaker 3 hours after cardioversion revealed reprogramming of the device and a marked rise in the lead impedance (>3,000 ohm. Removal of the generator and implantation of a biventricular cardioverter defibrillator were required. The emergency situation, the small size of the generator, the small incision made using the buried suture method, and the patient's obesity all probably contributed to the physician's not noticing the implanted pacemaker. It is important to increase awareness of the severe consequences that may follow if the physician administering external defibrillation does not know about the patient's implanted pacemaker.

Family environment patterns in families with bipolar children.

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Belardinelli, Cecilia; Hatch, John P; Olvera, Rene L; Fonseca, Manoela; Caetano, Sheila C; Nicoletti, Mark; Pliszka, Steven; Soares, Jair C

2008-04-01

We studied the characteristics of family functioning in bipolar children and healthy comparison children. We hypothesized that the family environment of bipolar children would show greater levels of dysfunction as measured by the Family Environment Scale (FES). We compared the family functioning of 36 families that included a child with DSM-IV bipolar disorder versus 29 comparison families that included only healthy children. All subjects and their parents were assessed with the K-SADS-PL interview. The parents completed the FES to assess their current family functioning. Multivariate analysis of variance was used to compare the family environment of families with and without offspring with bipolar disorder. Parents of bipolar children reported lower levels of family cohesion (pfamilies where a parent had a history of mood disorders compared to families where parents had no history of mood disorders. Length of illness in the affected child was inversely associated with family cohesion (r=-0.47, p=0.004). Due to the case-control design of the study, we cannot comment on the development of these family problems or attribute their cause specifically to child bipolar disorder. Families with bipolar children show dysfunctional patterns related to interpersonal interactions and personal growth. A distressed family environment should be addressed when treating children with bipolar disorder.

Clinical application of transvenous temporary cardiac pacemaker in performing extra-cranial carotid angiography and stent implantation

International Nuclear Information System (INIS)

Liu Juan; Yao Guoen; Zhou Huadong; Jiang Xiaojiang; Chen Qiao

2012-01-01

Objective: To assess the safety and effectiveness of transvenous temporary cardiac pacemaker in preventing hemodynamic instability occurred during the perioperative period of extra-cranial carotid angiography and stent implantation. Methods: Preoperative install of temporary cardiac pacemaker via left femoral vein was carried out in 41 patients who were at high risk for developing hemodynamic instability, which was followed by extra-cranial carotid angiography and stent implantation. The pacing rhythm of the pacemaker was fixed at 60 beats/min. During and after the procedure the patients were under close observation for the signs of discomfort symptoms as well as the changes in blood pressure and heart rate. The working condition of the pacemaker was also monitored. Results: All the installed pacemakers were technically and hemodynamically effective in producing electrical ventricular responses in all 25 patients who had received balloon dilatation of carotid in advance. Transient pacemaker activation appeared in 25 patients. The longest activation time was one day. During pacemaker activation, one patient developed symptomatic hypotension. The longest duration of hypotension lasted for 4 days. No pacemaker-related or procedure-related complications occurred. Conclusion: Hemodynamic instability is a common complication occurred during perioperative period of extra-cranial carotid angiography and stent implantation. As a prophylactic measure, preoperative placement of temporary cardiac pacemaker can promptly and effectively correct the hemodynamic disorders and prevent perioperative complications such as stroke, etc. Therefore, this technique is worth employing in clinical practice, and it is especially useful for patients with high risks. (authors)

Circadian Activators Are Expressed Days before They Initiate Clock Function in Late Pacemaker Neurons from Drosophila.

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Liu, Tianxin; Mahesh, Guruswamy; Houl, Jerry H; Hardin, Paul E

2015-06-03

Circadian pacemaker neurons in the Drosophila brain control daily rhythms in locomotor activity. These pacemaker neurons can be subdivided into early or late groups depending on whether rhythms in period (per) and timeless (tim) expression are initiated at the first instar (L1) larval stage or during metamorphosis, respectively. Because CLOCK-CYCLE (CLK-CYC) heterodimers initiate circadian oscillator function by activating per and tim transcription, a Clk-GFP transgene was used to mark when late pacemaker neurons begin to develop. We were surprised to see that CLK-GFP was already expressed in four of five clusters of late pacemaker neurons during the third instar (L3) larval stage. CLK-GFP is only detected in postmitotic neurons from L3 larvae, suggesting that these four late pacemaker neuron clusters are formed before the L3 larval stage. A GFP-cyc transgene was used to show that CYC, like CLK, is also expressed exclusively in pacemaker neurons from L3 larval brains, demonstrating that CLK-CYC is not sufficient to activate per and tim in late pacemaker neurons at the L3 larval stage. These results suggest that most late pacemaker neurons develop days before novel factors activate circadian oscillator function during metamorphosis. Copyright © 2015 the authors 0270-6474/15/358662-10$15.00/0.

Biological pacemaker created by minimally invasive somatic reprogramming in pigs with complete heart block

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Hu, Yu-Feng; Dawkins, James Frederick; Cho, Hee Cheol; Marbán, Eduardo; Cingolani, Eugenio

2016-01-01

Somatic reprogramming by reexpression of the embryonic transcription factor T-box 18 (TBX18) converts cardiomyocytes into pacemaker cells. We hypothesized that this could be a viable therapeutic avenue for pacemaker-dependent patients afflicted with device-related complications, and therefore tested whether adenoviral TBX18 gene transfer could create biological pacemaker activity in vivo in a large-animal model of complete heart block. Biological pacemaker activity, originating from the intramyocardial injection site, was evident in TBX18-transduced animals starting at day 2 and persisted for the duration of the study (14 days) with minimal backup electronic pacemaker use. Relative to controls transduced with a reporter gene, TBX18-transduced animals exhibited enhanced autonomic responses and physiologically superior chronotropic support of physical activity. Induced sinoatrial node cells could be identified by their distinctive morphology at the site of injection in TBX18-transduced animals, but not in controls. No local or systemic safety concerns arose. Thus, minimally invasive TBX18 gene transfer creates physiologically relevant pacemaker activity in complete heart block, providing evidence for therapeutic somatic reprogramming in a clinically relevant disease model. PMID:25031269

Bipolar disorder and dementia: where is the link?

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Masouy, Anaïs; Chopard, Gilles; Vandel, Pierre; Magnin, Eloi; Rumbach, Lucien; Sechter, Daniel; Haffen, Emmanuel

2011-03-01

Cognitive disorders appearing in the course of bipolar disease have been identified, and recent studies have defined the neuropsychological characteristics of this pathology, which includes attention, executive function, memory and language disorders. However, questions remain concerning the appearance of dementia symptoms over the course of bipolar disorder in certain patients: is it a chance association or is there a connection between bipolar disorders and dementia? If the latter hypothesis is considered, what is the nature of the dementia, which might be considered as a dementia specific to bipolar disorder? Current clinical, neuropsychological and cerebral imaging data are inconclusive, but similarities with frontotemporal dementia might be highlighted. Functional imaging studies might provide answers as well as more specific tests in neuropsychology. The cause of cognitive damage in bipolar disease also raises questions concerning a neurodevelopmental or neurodegenerative process, because several factors seem to influence cognition and these two processes might occur simultaneously. Long-term studies are necessary to determine whether cognitive deterioration in bipolar disease is stable or progressive. There might also be different neurobiological subgroups of patients with bipolar disease. © 2011 The Authors. Psychogeriatrics © 2011 Japanese Psychogeriatric Society.

Ductal carcinoma of the breast in the pacemaker generator's pocket.

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Zonca, P; Herokova, J; Cambal, M; Jacobi, C A

2009-01-01

Authors present a case of a 78-year-old female patient with invasive ductal adenocarcinoma in the pacemaker, s pocket. A decubitus-like tumor had developed in this place, and has been missinterpretated as a benign lesion for 5 months. Diagnosis was done with a time delay. An excisional biopsy revealed annvasive ductal adenocarcinoma. The first step was the implantation of a new pacemaker generator performed on the opposite side. The second step was a modified radical mastectomy, according to Madden, and the removal of the originally implanted pacemaker generator. Radiotherapy and hormonal adjuvant therapy were applied after surgery. The patient was followed-up at an out-patient clinic, and died 25 months after diagnosis because of generalization of the disease (Fig. 2, Ref. 35). Full Text (Free, PDF) www.bmj.sk.

First Degree Pacemaker Exit Block

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Johnson Francis

2016-10-01

Full Text Available Usually atrial and ventricular depolarizations follow soon after the pacemaker stimulus (spike on the ECG. But there can be an exit block due to fibrosis at the electrode - tissue interface at the lead tip. This can increase the delay between the spike and atrial or ventricular depolarization.

Radiation therapy planning of a breast cancer patient with in situ pacemaker-challenges and lessons

Energy Technology Data Exchange (ETDEWEB)

Munshi, Anusheel; Wadasadawala, Tabassum; Budrukkar, Ashwini; Jalali, Rakesh; Dinshaw, Ketayun A [Dept. of Radiation Oncology, Tata Memorial Hospital, Mumbai (India); Sharma, Pramod Kumar; Sharma, Dayananda [Dept. of Radiation Physics, Tata Memorial Hospital, Mumbai (India)

2008-02-15

A postmenopausal lady with an in situ pacemaker developed a lump in the left breast and was diagnosed to have breast cancer. The patient underwent breast conservative surgery and was planned for post operative radiotherapy. The location of the tumor relative to the pacemaker provided a unique challenge in planning radiotherapy and the patient had an uneventful post radiotherapy course. A literature review revealed that modern generation pacemakers are very sensitive to radiation compared to their older counterparts. The present article makes suggestions towards reducing dose in radiotherapy planning in pacemaker patients

Radiation therapy planning of a breast cancer patient with in situ pacemaker-challenges and lessons

International Nuclear Information System (INIS)

Munshi, Anusheel; Wadasadawala, Tabassum; Budrukkar, Ashwini; Jalali, Rakesh; Dinshaw, Ketayun A.; Sharma, Pramod Kumar; Sharma, Dayananda

2008-01-01

A postmenopausal lady with an in situ pacemaker developed a lump in the left breast and was diagnosed to have breast cancer. The patient underwent breast conservative surgery and was planned for post operative radiotherapy. The location of the tumor relative to the pacemaker provided a unique challenge in planning radiotherapy and the patient had an uneventful post radiotherapy course. A literature review revealed that modern generation pacemakers are very sensitive to radiation compared to their older counterparts. The present article makes suggestions towards reducing dose in radiotherapy planning in pacemaker patients

A forced desynchrony study of circadian pacemaker characteristics in seasonal affective disorder

NARCIS (Netherlands)

Koorengevel, Kathelijne M.; Beersma, Domien G.M.; den Boer, Johan; Hoofdakker, Rutger H. van den

2002-01-01

The circadian pacemaker is an endogenous clock that regulates oscillations in most physiological and psychological processes with a near 24-h period. In many species, this pacemaker triggers seasonal changes in behavior. The seasonality of symptoms and the efficacy of light therapy suggest

[Management of surgery patients with implanted cardiac pacemakers].

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Ugljen, R; Dadić, D; Ferek-Petrić, B; Jelić, I; Letica, D; Anić, D; Husar, J

1995-01-01

Patients having cardiac pacemaker implanted may be subjected to various general surgery procedures. Application of electrosurgery for the purpose of resection and coagulation, provides a high frequency electric field which produces electric voltage on the electrodes of the pacing system. This voltage may be detected within the pacing system, and various arrhythmias can be provoked in correlation with underlying rhythm and mode of pacing. Preoperative patient control and proper pacemaker programming can prevent the pacing malfunctions due to the electrosurgery application. Appropriate positioning of the neutral electrode in relation to the pacing system avoids the electric fields intersection and decreases their interference.

Radiotherapy for breast cancer and pacemaker; Radiotherapie pour un cancer du sein et stimulateur cardiaque

Energy Technology Data Exchange (ETDEWEB)

Menard, J.; Campana, F.; Bollet, M.A.; Dendale, R.; Fournier-Bidoz, N.; Marchand, V.; Mazal, A.; Fourquet, A.; Kirova, Y.M. [Oncologie-radiotherapie, institut Curie, 26, rue d' Ulm, 75005 Paris (France); Kirov, K.M.; Esteve, M. [Departement d' anesthesie-reanimation-douleur, institut Curie, 75005 Paris (France)

2011-06-15

Purpose. - Patients with permanent cardiac pacemakers occasionally require radiotherapy. Therapeutic Irradiation may cause pacemakers to malfunction due to the effects of ionizing radiation or electromagnetic interference. We studied the breast cancer patients who needed breast and/or chest wall and lymph node irradiation to assess the feasibility and tolerance in this population of patients. Patients and methods. - From November 2008 to December 2009, more than 900 patients received radiotherapy for their breast cancer in our department using megavoltage linear accelerator (X 4-6 MV and electrons). Among them, seven patients were with permanent pacemaker. All patients have been treated to the breast and chest wall and/or lymph nodes. Total dose to breast and/or chest wall was 50 Gy/25 fractions and 46 Gy/23 fractions to lymph nodes. Patients who underwent conserving surgery followed by breast irradiation were boosted when indicated to tumour bed with 16 Gy/8 fractions. All patients were monitored everyday in presence of radiation oncologist to follow the function of their pacemaker. All pacemakers were controlled before and after radiotherapy by the patients' cardiologist. Results. - Seven patients were referred in our department for postoperative breast cancer radiotherapy. Among them, only one patient was declined for radiotherapy and underwent mastectomy without radiotherapy. In four cases the pacemaker was repositioned before the beginning of radiotherapy. Six patients, aged between 48 and 84 years underwent irradiation for their breast cancer. Four patients were treated with conserving surgery followed by breast radiotherapy and two with mastectomy followed by chest wall and internal mammary chain, supra- and infra-clavicular lymph node irradiation. The dose to the pacemaker generator was kept below 2 Gy. There was no pacemaker dysfunction observed during the radiotherapy. Conclusion. - The multidisciplinary work with position change of the pacemaker

Cognitive processes and attitudes in bipolar disorder: a study into personality, dysfunctional attitudes and attention bias in patients with bipolar disorder and their relatives.

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Jabben, Nienke; Arts, Baer; Jongen, Ellen M M; Smulders, Fren T Y; van Os, Jim; Krabbendam, Lydia

2012-12-20

Research in cognitive processes and attitudes in bipolar disorder is scarce and has provided mixed findings, possibly due to differences in current mood state. It is unclear whether alterations in cognitive processes and attitudes are only related to the depressive mood states of bipolar patients or also represent a vulnerability marker for the development of future (depressive) episodes. This was investigated in the current study. Both implicit (attentional bias for emotional words) and explicit (dysfunctional attitudes and personality characteristics) measures of cognitive processes and attitudes were assessed in 77 bipolar patients with varying levels of depressive symptoms (depressed=17, euthymic n=60), their healthy first-degree relatives (n=39) and a healthy control group (n=61). Analyses of variance were used to investigate differences between groups. Mildly depressed patients with bipolar disorder demonstrated an attentional bias away from positive emotional words and showed increased dysfunctional attitudes and higher levels of neuroticism. Euthymic patients were largely comparable to healthy controls and only differed from controls in higher levels of neuroticism. Relatives were similar to controls on all measures, although they significantly differed from bipolar patients in displaying less neuroticism and more extraversion. No firm conclusions regarding causality can be drawn from the associations that were found between cognitive processes and attitudes and the evolution of mood symptoms in bipolar disorder. Alterations in cognitive processes and attitudes in bipolar patients appear to be mostly related to the expression of mood symptomatology rather than to the vulnerability for bipolar disorder. Copyright © 2012 Elsevier B.V. All rights reserved.

Evaluation of cumulative effects of MR imaging on pacemaker systems at 1.5 Tesla.

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Naehle, Claas P; Zeijlemaker, Volkert; Thomas, Daniel; Meyer, Carsten; Strach, Katharina; Fimmers, Rolf; Schild, Hans; Sommer, Torsten

2009-12-01

The purpose of this study was to evaluate possible cumulative effects of repeated magnetic resonance imaging (MRI) examinations on pacemaker systems in patients with cardiac pacemakers. The records of pacemaker patients who underwent repetitive MRI examinations in our institution were reviewed to identify patients who underwent two or more MRI examinations at 1.5T of any anatomical region. Using these criteria, a total of 47 patients who underwent a total 171 MRI examinations were identified and included in this study. Institutional Review Board approval for all pacemaker investigations was obtained. Written informed consent was obtained from all patients. Pacemakers were interrogated immediately before and after MR imaging, and after 3 months, including measurement of pacing capture threshold (PCT), lead impedance (LI), and battery voltage (BV). PCT, LI, and BV were analyzed for changes dependant on the number of MRI exams performed. Mean changes over time and changes between first and last pacemaker interrogation of PCT, LI, and BV were calculated. A statistically significant (P < 0.05), but clinically irrelevant trend for decrease in PCT and BV was found. No significant or clinically relevant changes in LI were observed. In this first study, no clinically relevant, cumulative changes in PCT, LI, or BV could be detected in PM patients who underwent two or more MRI examinations. However, a careful benefit/risk evaluation, among other MRI- and pacemaker-related safety precautions, remains mandatory, as clinically relevant alterations to the PM system cannot be excluded by all means.

Modeling suicide in bipolar disorders.

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Malhi, Gin S; Outhred, Tim; Das, Pritha; Morris, Grace; Hamilton, Amber; Mannie, Zola

2018-02-19

Suicide is a multicausal human behavior, with devastating and immensely distressing consequences. Its prevalence is estimated to be 20-30 times greater in patients with bipolar disorders than in the general population. The burden of suicide and its high prevalence in bipolar disorders make it imperative that our current understanding be improved to facilitate prediction of suicide and its prevention. In this review, we provide a new perspective on the process of suicide in bipolar disorder, in the form of a novel integrated model that is derived from extant knowledge and recent evidence. A literature search of articles on suicide in bipolar disorder was conducted in recognized databases such as Scopus, PubMed, and PsycINFO using the keywords "suicide", "suicide in bipolar disorders", "suicide process", "suicide risk", "neurobiology of suicide" and "suicide models". Bibliographies of identified articles were further scrutinized for papers and book chapters of relevance. Risk factors for suicide in bipolar disorders are well described, and provide a basis for a framework of epigenetic mechanisms, moderated by neurobiological substrates, neurocognitive functioning, and social inferences within the environment. Relevant models and theories include the diathesis-stress model, the bipolar model of suicide and the ideation-to-action models, the interpersonal theory of suicide, the integrated motivational-volitional model, and the three-step theory. Together, these models provide a basis for the generation of an integrated model that illuminates the suicidal process, from ideation to action. Suicide is complex, and it is evident that a multidimensional and integrated approach is required to reduce its prevalence. The proposed model exposes and provides access to components of the suicide process that are potentially measurable and may serve as novel and specific therapeutic targets for interventions in the context of bipolar disorder. Thus, this model is useful not only

DeepBipolar: Identifying genomic mutations for bipolar disorder via deep learning.

Science.gov (United States)

Laksshman, Sundaram; Bhat, Rajendra Rana; Viswanath, Vivek; Li, Xiaolin

2017-09-01

Bipolar disorder, also known as manic depression, is a brain disorder that affects the brain structure of a patient. It results in extreme mood swings, severe states of depression, and overexcitement simultaneously. It is estimated that roughly 3% of the population of the United States (about 5.3 million adults) suffers from bipolar disorder. Recent research efforts like the Twin studies have demonstrated a high heritability factor for the disorder, making genomics a viable alternative for detecting and treating bipolar disorder, in addition to the conventional lengthy and costly postsymptom clinical diagnosis. Motivated by this study, leveraging several emerging deep learning algorithms, we design an end-to-end deep learning architecture (called DeepBipolar) to predict bipolar disorder based on limited genomic data. DeepBipolar adopts the Deep Convolutional Neural Network (DCNN) architecture that automatically extracts features from genotype information to predict the bipolar phenotype. We participated in the Critical Assessment of Genome Interpretation (CAGI) bipolar disorder challenge and DeepBipolar was considered the most successful by the independent assessor. In this work, we thoroughly evaluate the performance of DeepBipolar and analyze the type of signals we believe could have affected the classifier in distinguishing the case samples from the control set. © 2017 Wiley Periodicals, Inc.

Progression along the Bipolar Spectrum: A Longitudinal Study of Predictors of Conversion from Bipolar Spectrum Conditions to Bipolar I and II Disorders

Science.gov (United States)

Alloy, Lauren B.; Urošević, Snežana; Abramson, Lyn Y.; Jager-Hyman, Shari; Nusslock, Robin; Whitehouse, Wayne G.; Hogan, Michael

2011-01-01

Little longitudinal research has examined progression to more severe bipolar disorders in individuals with “soft” bipolar spectrum conditions. We examine rates and predictors of progression to bipolar I and II diagnoses in a non-patient sample of college-age participants (n = 201) with high General Behavior Inventory scores and childhood or adolescent onset of “soft” bipolar spectrum disorders followed longitudinally for 4.5 years from the Longitudinal Investigation of Bipolar Spectrum (LIBS) project. Of 57 individuals with initial cyclothymia or bipolar disorder not otherwise specified (BiNOS) diagnoses, 42.1% progressed to a bipolar II diagnosis and 10.5% progressed to a bipolar I diagnosis. Of 144 individuals with initial bipolar II diagnoses, 17.4% progressed to a bipolar I diagnosis. Consistent with hypotheses derived from the clinical literature and the Behavioral Approach System (BAS) model of bipolar disorder, and controlling for relevant variables (length of follow-up, initial depressive and hypomanic symptoms, treatment-seeking, and family history), high BAS sensitivity (especially BAS Fun Seeking) predicted a greater likelihood of progression to bipolar II disorder, whereas early age of onset and high impulsivity predicted a greater likelihood of progression to bipolar I (high BAS sensitivity and Fun-Seeking also predicted progression to bipolar I when family history was not controlled). The interaction of high BAS and high Behavioral Inhibition System (BIS) sensitivities also predicted greater likelihood of progression to bipolar I. We discuss implications of the findings for the bipolar spectrum concept, the BAS model of bipolar disorder, and early intervention efforts. PMID:21668080

Genetic utility of broadly defined bipolar schizoaffective disorder as a diagnostic concept

Science.gov (United States)

Hamshere, M. L.; Green, E. K.; Jones, I. R.; Jones, L.; Moskvina, V.; Kirov, G.; Grozeva, D.; Nikolov, I.; Vukcevic, D.; Caesar, S.; Gordon-Smith, K.; Fraser, C.; Russell, E.; Breen, G.; St Clair, D.; Collier, D. A.; Young, A. H.; Ferrier, I. N.; Farmer, A.; McGuffin, P.; Holmans, P. A.; Owen, M. J.; O’Donovan, M. C.; Craddock, N.

2009-01-01

Background Psychiatric phenotypes are currently defined according to sets of descriptive criteria. Although many of these phenotypes are heritable, it would be useful to know whether any of the various diagnostic categories in current use identify cases that are particularly helpful for biological–genetic research. Aims To use genome-wide genetic association data to explore the relative genetic utility of seven different descriptive operational diagnostic categories relevant to bipolar illness within a large UK case–control bipolar disorder sample. Method We analysed our previously published Wellcome Trust Case Control Consortium (WTCCC) bipolar disorder genome-wide association data-set, comprising 1868 individuals with bipolar disorder and 2938 controls genotyped for 276 122 single nucleotide polymorphisms (SNPs) that met stringent criteria for genotype quality. For each SNP we performed a test of association (bipolar disorder group v. control group) and used the number of associated independent SNPs statistically significant at Pschizoaffective disorder, bipolar type; DSM–IV: bipolar I disorder; bipolar II disorder; schizoaffective disorder, bipolar type. Results The RDC schizoaffective disorder, bipolar type (v. controls) stood out from the other diagnostic subsets as having a significant excess of independent association signals (Pschizoaffective features have either a particularly strong genetic contribution or that, as a group, are genetically more homogeneous than the other phenotypes tested. The results point to the importance of using diagnostic approaches that recognise this group of individuals. Our approach can be applied to similar data-sets for other psychiatric and non-psychiatric phenotypes. PMID:19567891

76 FR 53851 - Effective Date of Requirement for Premarket Approval for Cardiovascular Permanent Pacemaker...

Science.gov (United States)

2011-08-30

... Pacemaker Electrode; Correction AGENCY: Food and Drug Administration, HHS. ACTION: Proposed rule; correction... preamendments device: Cardiovascular permanent pacemaker electrode. The document was published with an incorrect...

The oral cavity is not a primary source for implantable pacemaker or cardioverter defibrillator infections

Science.gov (United States)

2013-01-01

Background To test the hypothesis that the oral cavity is a potential source for implantable pacemaker and cardioverter defibrillators infections, the bacterial diversity on explanted rhythm heart management devices was investigated and compared to the oral microbiome. Methods A metagenomic approach was used to analyze the bacterial diversity on the surfaces of non-infected and infected pacemakers. The DNA from surfaces swaps of 24 non-infected and 23 infected pacemaker were isolated and subjected to bacterial-specific DNA amplification, single strand conformation polymorphism- (SSCP) and sequencing analysis. Species-specific primer sets were used to analyze for any correlation between bacterial diversity on pacemakers and in the oral cavity. Results DNA of bacterial origin was detected in 21 cases on infected pacemakers and assigned to the bacterial phylotypes Staphylococcus epidermidis, Propionibacterium acnes, Staphylococcus aureus, Staphylococcus schleiferi and Stapyhlococcus. In 17 cases bacterial DNA was found on pacemakers with no clinical signs of infections. On the basis of the obtained sequence data, the phylotypes Propionibacterium acnes, Staphylococcus and an uncultured bacterium were identified. Propionibacterium acnes and Staphylococcus epidermidis were the only bacteria detected in pacemeaker (n = 25) and oral samples (n = 11). Conclusions The frequency of the coincidental detection of bacteria on infected devices and in the oral cavity is low and the detected bacteria are highly abundant colonizers of non-oral human niches. The transmission of oral bacteria to the lead or device of implantable pacemaker or cardioverter defibrillators is unlikely relevant for the pathogenesis of pacemaker or cardioverter defibrillators infections. PMID:23575037

Quetiapine monotherapy for bipolar depression

Directory of Open Access Journals (Sweden)

Michael E Thase

2008-03-01

Full Text Available Michael E ThaseDepartments of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, PA, USA; the Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, USA; and the University of Pittsburgh Medical Center, Pittsburgh, PA, USAAbstract: Bipolar depression is more common, disabling, and difficult-to-treat than the manic and hypomanic phases that define bipolar disorder. Unlike the treatment of so-called “unipolar” depressions, antidepressants generally are not indicated as monotherapies for bipolar depressions and recent studies suggest that - even when used in combination with traditional mood stabilizers – antidepressants may have questionable value for bipolar depression. The current practice is that mood stabilizers are initiated first as monotherapies; however, the antidepressant efficacy of lithium and valproate is modest at best. Within this context the role of atypical antipsychotics is being evaluated. The combination of olanzapine and the antidepressant fluoxetine was the first treatment to receive regulatory approval in the US specifically for bipolar I depression. Quetiapine was the second medication to be approved for this indication, largely as the result of two pivotal trials known by the acronyms of BOLDER (BipOLar DEpRession I and II. Both studies demonstrated that two doses of quetiapine (300 mg and 600 mg given once daily at bedtime were significantly more effective than placebo, with no increased risk of patients switching into mania. Pooling the two studies, quetiapine was effective for both bipolar I and bipolar II depressions and for patients with (and without a history of rapid cycling. The two doses were comparably effective in both studies. Although the efficacy of quetiapine monotherapy has been established, much additional research is necessary. Further studies are needed to more fully investigate dose-response relationships and comparing quetiapine monotherapy to other mood stabilizers

Surgical outcome of Fontan conversion and arrhythmia surgery: Need a pacemaker?

Science.gov (United States)

Terada, Takafumi; Sakurai, Hajime; Nonaka, Toshimichi; Sakurai, Takahisa; Sugiura, Junya; Taneichi, Tetsuyoshi; Ohtsuka, Ryohei

2014-07-01

Atrial tachyarrhythmias are frequent complications in the late period after the Fontan procedure, and important risk factors for a poor prognosis. The impact of Fontan conversion and arrhythmia surgery in failed Fontan patients has been described in many reports. We evaluated our experience with Fontan conversion procedures, concomitant arrhythmia surgery, and pacemaker implantation. We reviewed the hospital records of 25 consecutive patients who underwent a Fontan conversion procedure from January 2004 to March 2012. Twenty-four patients had arrhythmia surgery using cryoablation and radiofrequency ablation at the time of conversion. A bilateral atrial maze procedure was performed in 6 patients, right-side maze in 15, and isthmus block in 3. Three patients with a diagnosis of corrected transposition of the great arteries underwent simultaneous pacemaker implantation electively. There was no early death and one late death during a mean follow-up period of 21.2 months. Three tachyarrhythmia recurrences developed, and there were 4 occurrences of sinus bradycardia. Five of these patients required postoperative pacemaker implantation. The mid-term results of Fontan conversion and arrhythmia surgery in our institute were satisfactory. The occurrence of unexpected postoperative pacemaker requirement was high in the patients who underwent a right atrial or bilateral atrial maze procedure. Pacemaker or lead implantation is recommended for patients planned to undergo a right-side or full maze procedure. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Suicide in bipolar disorder: a review.

Science.gov (United States)

Latalova, Klara; Kamaradova, Dana; Prasko, Jan

2014-06-01

Suicide is a leading cause of death in patients with bipolar disorder. Risk factors and prevention of suicide in this illness are the focus of considerable current research. MEDLINE data base was searched for the key words "bipolar disorder" with "suicide", "lithium" with "suicide", "anticonvulsants" with "bipolar disorder", and "anticonvulsants" with "bipolar disorder" and with "suicide". No language or time constraints were applied. The lists of references were searched manually to find additional articles. It is estimated that 25% to 50% of patients with bipolar disorder will attempt suicide at least once over their lifetime, and that 8% to 19% will complete suicide. Mortality rates from cardiovascular diseases are elevated in bipolar disorder. Risk factors for suicide include younger age of onset of the illness, history of past suicidal behavior, family history of suicide acts, comorbid borderline personality disorder and substance use disorders, and hopelessness. The warning signs calling for immediate action include the patients threatening to harm themselves, or looking for ways to kill themselves (seeking access to pills or weapons), or the patient talking or writing about death. Robust evidence supports the effects of lithium treatment in reducing suicidal attempts and completions in bipolar disorder. The evidence for antisuicidal effects of anticonvulsants is weaker. Nevertheless, valproate and other anticonvulsants are frequently prescribed as mood stabilizers. There have been controversial suggestions that this treatment may elevate the risk of suicide, but the data supporting this are not convincing. Psychoeducation can reduce the number of suicide attempts and completions. Suicide in bipolar disorder is a major public health problem. Recent research has expanded our knowledge of risk factors and warning signs. Nevertheless, it appears that the introduction of lithium treatment in the 1970s was the most recent important breakthrough in the prevention

Bipolar one diode-one resistor integration for high-density resistive memory applications.

Science.gov (United States)

Li, Yingtao; Lv, Hangbing; Liu, Qi; Long, Shibing; Wang, Ming; Xie, Hongwei; Zhang, Kangwei; Huo, Zongliang; Liu, Ming

2013-06-07

Different from conventional unipolar-type 1D-1R RRAM devices, a bipolar-type 1D-1R memory device concept is proposed and successfully demonstrated by the integration of Ni/TiOx/Ti diode and Pt/HfO2/Cu bipolar RRAM cell to suppress the undesired sneak current in a cross-point array. The bipolar 1D-1R memory device not only achieves self-compliance resistive switching characteristics by the reverse bias current of the Ni/TiOx/Ti diode, but also exhibits excellent bipolar resistive switching characteristics such as uniform switching, satisfactory data retention, and excellent scalability, which give it high potentiality for high-density integrated nonvolatile memory applications.

Gene- and cell-based bio-artificial pacemaker: what basic and translational lessons have we learned?

Science.gov (United States)

Li, R A

2012-06-01

Normal rhythms originate in the sino-atrial node, a specialized cardiac tissue consisting of only a few thousands of nodal pacemaker cells. Malfunction of pacemaker cells due to diseases or aging leads to rhythm generation disorders (for example, bradycardias and sick-sinus syndrome (SSS)), which often necessitate the implantation of electronic pacemakers. Although effective, electronic devices are associated with such shortcomings as limited battery life, permanent implantation of leads, lead dislodging, the lack of autonomic responses and so on. Here, various gene- and cell-based approaches, with a particular emphasis placed on the use of pluripotent stem cells and the hyperpolarization-activated cyclic nucleotide-gated-encoded pacemaker gene family, that have been pursued in the past decade to reconstruct bio-artificial pacemakers as alternatives will be discussed in relation to the basic biological insights and translational regenerative potential.

Leadless pacemaker extraction from a single-center perspective.

Science.gov (United States)

González Villegas, Elkin; Al Razzo, Omar; Silvestre García, Jorge; Mesa García, José

2018-02-01

Leadless pacemaker can be considered as a technical revolution in cardiac pacing devices, with clear advantages over conventional pacemakers in overcoming all lead-related complications. However, the management of these devices once they reach the end of life (EOL) of the battery is still controversial. In the next years, there will be an increase in the need to define a clear strategy in the management of leadless PM once they reach their EOL. Safe extraction of these devices will define in a great manner this strategy METHODS: We performed the extraction of three functioning Nanostim leadless pacemaker prophylactically in two females and one male patients as part of the Nanostim battery depletion field action recommendation. All patients had a prior transesophageal 3D echocardiography to determine the device intracardiac mobility and the extent of possible endothelialization. For the extractions, we used the Nanostim Retrieval Catheter S1RSIN (St. Jude Medical, St. Paul, MN, USA), which is a proprietary catheter provided by the manufacturing company based on a lasso. Complete extraction of the devices was achieved in all patients using a relatively short fluoroscopic time (16, 19, and 12 minutes). The extraction of leadless pacemakers can be considered as a safe and feasible procedure using the tools provided by the manufacturer and designed for the extraction. However, a very low threshold must be maintained to avoid any risk to the patients. Our extraction time ranges are between 983 and 1,070 days, nevertheless it is necessary to gather more long-term data to assess the feasibility and safety of these procedures. © 2017 Wiley Periodicals, Inc.

Cognitive processes and attitudes in bipolar disorder: A study into personality, dysfunctional attitudes and attention bias in patients with bipolar disorder and their relatives

NARCIS (Netherlands)

Jabben, N.E.J.G.; Arts, B.; Jongen, E.M.M.; Smulders, F.T.Y.; van Os, J.; Krabbendam, L.

2012-01-01

Background: Research in cognitive processes and attitudes in bipolar disorder is scarce and has provided mixed findings, possibly due to differences in current mood state. It is unclear whether alterations in cognitive processes and attitudes are only related to the depressive mood states of bipolar

Bipolar cloud-to-ground lightning flash observations

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Saba, Marcelo M. F.; Schumann, Carina; Warner, Tom A.; Helsdon, John H.; Schulz, Wolfgang; Orville, Richard E.

2013-10-01

lightning is usually defined as a lightning flash where the current waveform exhibits a polarity reversal. There are very few reported cases of cloud-to-ground (CG) bipolar flashes using only one channel in the literature. Reports on this type of bipolar flashes are not common due to the fact that in order to confirm that currents of both polarities follow the same channel to the ground, one necessarily needs video records. This study presents five clear observations of single-channel bipolar CG flashes. High-speed video and electric field measurement observations are used and analyzed. Based on the video images obtained and based on previous observations of positive CG flashes with high-speed cameras, we suggest that positive leader branches which do not participate in the initial return stroke of a positive cloud-to-ground flash later generate recoil leaders whose negative ends, upon reaching the branch point, traverse the return stroke channel path to the ground resulting in a subsequent return stroke of opposite polarity.

Transvenous permanent pacemaker implantation in dextrocardia: technique, challenges, outcome, and a brief review of literature.

Science.gov (United States)

Shenthar, Jayaprakash; Rai, Maneesh K; Walia, Rohit; Ghanta, Somasekhar; Sreekumar, Praveen; Reddy, Satish S

2014-09-01

Dextrocardia is a rare congenital anomaly. Pacemaker implantation in dextrocardia can be challenging because of the distorted anatomy and associated anomalies. The literature regarding implantation of pacemaker in dextrocardia is scarce. The study involved retrospective analysis of records of patients with dextrocardia who had undergone pacemaker implantation between January 2006 and July 2013 from a single centre. Six patients with dextrocardia (five males and one female) underwent permanent pacemaker implantation (PPI) between January 2006 and July 2013. Of them, three had situs solitus dextrocardia and three situs inversus dextrocardia. All three patients with situs solitus dextrocardia had associated corrected transposition of great arteries. The indication for pacemaker implantation was symptomatic complete atrioventricular (AV) block in four, high-grade AV block in one, and sinus node dysfunction in one patient. A favourable outcome was noted during a mean follow-up of 3.9 years (4 months to 7 years) with one patient needing a pulse generator replacement. Permanent pacemaker implantation in dextrocardia can be challenging because of the distorted anatomy. Use of a technique employing angiography to delineate chamber anatomy and relationship can assist the operator during such difficult PPIs. The medium- and long-term survival after a successful pacemaker implantation in dextrocardia is favourable. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

ARTERIAL HYPERTENSION AND MEDICAL SUPPORT OF PATIENTS WITH PERMANENT PACEMAKERS

Directory of Open Access Journals (Sweden)

T. A. Derienko

2016-06-01

Full Text Available The review is devoted to clinical problems of arterial hypertension (AH in patients with implanted pacemakers (EKS and cardiac resynchronization therapy (CRT. Indications for pacemaker implantation and CRT are considered, especially the purpose and effectiveness of angiotensin-converting enzyme (ACE inhibitors, angiotensin II receptor antagonists (ARA, sartans, beta-blockers (BAB, diuretics, calcium channel blockers. We prove that the CRT and cardiac pacing and do not cancel, bur modify drug therapy of AH.

Incidence of ventricular tachyarrhythmias during permanent pacemaker therapy in low-risk patients results from the German multicentre EVENTS study.

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Faber, Thomas S; Gradinger, Robert; Treusch, Sven; Morkel, Carsten; Brachmann, Johannes; Bode, Christoph; Zehender, Manfred

2007-09-01

Current studies found an incidence of 12-31% ventricular tachyarrhythmias and sudden cardiac death during cardiac pacing months or even years after pacemaker insertion. MADIT(12) and MUSTT(13) demonstrated that patients with poor LV function after Myocardial infarction (MI) showing non-sustained ventricular tachycardia (nsVT) and inducibility during electrophysiologic testing benefit from an ICD. The present study was dedicated to assess the global incidence of non-sustained ventricular arrhythmias in a general population of pacemaker patients. Special regard was on patients with a potential ICD indication, e.g. those matching the MADIT/MUSTT criteria. Two hundred and thirty-one patients (72 +/- 11 years; 134 men) with an indication for dual chamber pacing entered the study. In all patients pacemaker systems capable of automatic storing of intracardiac electrocardiograms were implanted (Pulsar, Discovery, Guidant). Follow-up time was 15 months after inclusion. In 54 (25.7%) of 210 patients with at least one follow-up, episodes of nsVT were documented by stored electrocardiograms (up to >30 beats, >200 b.p.m.). Multiple-up to nine-episodes of ventricular tachycardia were retrieved in 31 of these patients. Three out of 14 patients with an LVEF <40% after MI presented nsVT during the follow-up. One of these patients received an ICD. A significant number of pacemaker patients present with ventricular tachycardia. Intracardiac electrocardiograms and alert functions from pacemakers may enhance physicians' awareness of the patient's intrinsic arrhythmic profile and help uncover underlying mechanisms of arrhythmias by storing the initiation of the arrhythmia.

Long-Term Mortality Effect of Early Pacemaker Implantation After Surgical Aortic Valve Replacement.

Science.gov (United States)

Greason, Kevin L; Lahr, Brian D; Stulak, John M; Cha, Yong-Mei; Rea, Robert F; Schaff, Hartzell V; Dearani, Joseph A

2017-10-01

The need for pacemaker implantation is a well-described complication of aortic valve replacement. Not so well described is the effect such an event has on long-term outcome. This study reviewed a 21-year experience at the Mayo Clinic (Rochester, Minnesota) with aortic valve replacement to understand the influence of early postoperative pacemaker implantation on long-term mortality rates more clearly. This study retrospectively reviewed the records of 5,842 patients without previous pacemaker implantation who underwent surgical aortic valve replacement from January 1993 through June 2014. The median age of these patients was 73 years (range, 65 to 79 years), the median ejection fraction was 62% (range, 53% to 68%), 3,853 patients were male (66%), and coronary artery bypass graft operation was performed in 2,553 (44%) of the patients studied. Early pacemaker implantation occurred in 146 patients (2.5%) within 30 days of surgical aortic valve replacement. The median follow-up of patients was 11.1 years (range, 5.8 to 16.5 years), and all-cause mortality rates were 2.4% at 30 days, 6.4% at 1 year, 23.1% at 5 years, 48.3% at 10 years, and 67.9% at 15 years postoperatively. Early pacemaker implantation was associated with an increased risk of death after multivariable adjustment for baseline patients' characteristics (hazard ratio, 1.49; 95% confidence interval, 1.20, 1.84; p pacemaker implantation as a complication of surgical aortic valve replacement is associated with an increased risk of long-term death. Valve replacement-related pacemaker implantation rates should be important considerations with respect to new valve replacement paradigms, especially in younger and lower-risk patients. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Ectopic jejunal pacemakers and gastric emptying after Roux gastrectomy: Effect of intestinal pacing

International Nuclear Information System (INIS)

Karlstrom, L.; Kelly, K.A.

1989-01-01

The aims of this study were to determine whether ectopic pacemakers are present after meals in the Roux limbs of dogs after vagotomy and Roux gastrectomy, whether these pacemakers slow gastric emptying of liquids or solids, and whether abolishing the pacemakers with electric pacing might speed any slow emptying that occurs. In six dogs that underwent vagotomy and Roux gastrectomy and in four dogs that underwent vagotomy and Billroth gastrectomy (controls), myoelectric activity of the Roux limb or duodenum was measured during gastric emptying of a 500 kcal mixed meal of 99mTc-labeled cooked egg and 111In-labeled milk. Roux dogs were tested with and without pacing of the Roux limb. Roux dogs showed ectopic pacemaker in the Roux limb that drove the pacesetter potentials of the limb in a reverse, or orad, direction during 57% of the postprandial recordings. Billroth dogs had no ectopic pacemakers (p less than 0.05). Liquids emptied more slowly in Roux dogs (half-life (t1/2) = 121 +/- 15 minutes) than in Billroth dogs (t1/2 = 43 +/- 9 minutes; p less than 0.05), but solids emptied similarly in both groups of dogs (t1/2 approximately 8 hours). Pacing the Roux limb abolished the ectopic pacemakers, restored the slow emptying of liquids to the more rapid rate found in the Billroth dogs (t1/2: paced Roux, 72 +/- 15 minutes; Billroth, 43 +/- 9 minutes; p greater than 0.05) and did not change emptying of solids. The conclusion was that ectopic pacemakers present in the Roux limb after vagotomy and Roux gastrectomy drove the limb in a reverse direction and slowed emptying of liquids after the operation. The defect was corrected by pacing the Roux limb in a forward direction

Ectopic jejunal pacemakers and gastric emptying after Roux gastrectomy: Effect of intestinal pacing

Energy Technology Data Exchange (ETDEWEB)

Karlstrom, L.; Kelly, K.A. (Mayo Clinic, Rochester, MN (USA))

1989-11-01

The aims of this study were to determine whether ectopic pacemakers are present after meals in the Roux limbs of dogs after vagotomy and Roux gastrectomy, whether these pacemakers slow gastric emptying of liquids or solids, and whether abolishing the pacemakers with electric pacing might speed any slow emptying that occurs. In six dogs that underwent vagotomy and Roux gastrectomy and in four dogs that underwent vagotomy and Billroth gastrectomy (controls), myoelectric activity of the Roux limb or duodenum was measured during gastric emptying of a 500 kcal mixed meal of 99mTc-labeled cooked egg and 111In-labeled milk. Roux dogs were tested with and without pacing of the Roux limb. Roux dogs showed ectopic pacemaker in the Roux limb that drove the pacesetter potentials of the limb in a reverse, or orad, direction during 57% of the postprandial recordings. Billroth dogs had no ectopic pacemakers (p less than 0.05). Liquids emptied more slowly in Roux dogs (half-life (t1/2) = 121 +/- 15 minutes) than in Billroth dogs (t1/2 = 43 +/- 9 minutes; p less than 0.05), but solids emptied similarly in both groups of dogs (t1/2 approximately 8 hours). Pacing the Roux limb abolished the ectopic pacemakers, restored the slow emptying of liquids to the more rapid rate found in the Billroth dogs (t1/2: paced Roux, 72 +/- 15 minutes; Billroth, 43 +/- 9 minutes; p greater than 0.05) and did not change emptying of solids. The conclusion was that ectopic pacemakers present in the Roux limb after vagotomy and Roux gastrectomy drove the limb in a reverse direction and slowed emptying of liquids after the operation. The defect was corrected by pacing the Roux limb in a forward direction.

Pacemaker-driven stochastic resonance on diffusive and complex networks of bistable oscillators

Energy Technology Data Exchange (ETDEWEB)

Perc, Matjaz; Gosak, Marko [Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Koroska cesta 160, SI-2000 Maribor (Slovenia)], E-mail: matjaz.perc@uni-mb.si

2008-05-15

We study the phenomenon of stochastic resonance on diffusive, small-world and scale-free networks consisting of bistable overdamped oscillators. Important thereby is the fact that the external subthreshold periodic forcing is introduced only to a single oscillator of the network. Hence, the forcing acts as a pacemaker trying to impose its rhythm on the whole network through the unit to which it is introduced. Without the addition of additive spatiotemporal noise, however, the whole network, including the unit that is directly exposed to the pacemaker, remains trapped forever in one of the two stable steady states of the local dynamics. We show that the correlation between the frequency of subthreshold pacemaker activity and the response of the network is resonantly dependent on the intensity of additive noise. The reported pacemaker-driven stochastic resonance depends most significantly on the coupling strength and the underlying network structure. Namely, the outreach of the pacemaker obeys the classic diffusion law in the case of nearest-neighbor interactions, thus being proportional to the square root of the coupling strength, whereas it becomes superdiffusive by an appropriate small-world or scale-free topology of the interaction network. In particular, the scale-free topology is identified as being optimal for the dissemination of localized rhythmic activity across the whole network. Also, we show that the ratio between the clustering coefficient and the characteristic path length is the crucial quantity defining the ability of a small-world network to facilitate the outreach of the pacemaker-emitted subthreshold rhythm. We additionally confirm these findings by using the FitzHugh-Nagumo excitable system as an alternative to the bistable overdamped oscillator.

Pacemaker-driven stochastic resonance on diffusive and complex networks of bistable oscillators

International Nuclear Information System (INIS)

Perc, Matjaz; Gosak, Marko

2008-01-01

We study the phenomenon of stochastic resonance on diffusive, small-world and scale-free networks consisting of bistable overdamped oscillators. Important thereby is the fact that the external subthreshold periodic forcing is introduced only to a single oscillator of the network. Hence, the forcing acts as a pacemaker trying to impose its rhythm on the whole network through the unit to which it is introduced. Without the addition of additive spatiotemporal noise, however, the whole network, including the unit that is directly exposed to the pacemaker, remains trapped forever in one of the two stable steady states of the local dynamics. We show that the correlation between the frequency of subthreshold pacemaker activity and the response of the network is resonantly dependent on the intensity of additive noise. The reported pacemaker-driven stochastic resonance depends most significantly on the coupling strength and the underlying network structure. Namely, the outreach of the pacemaker obeys the classic diffusion law in the case of nearest-neighbor interactions, thus being proportional to the square root of the coupling strength, whereas it becomes superdiffusive by an appropriate small-world or scale-free topology of the interaction network. In particular, the scale-free topology is identified as being optimal for the dissemination of localized rhythmic activity across the whole network. Also, we show that the ratio between the clustering coefficient and the characteristic path length is the crucial quantity defining the ability of a small-world network to facilitate the outreach of the pacemaker-emitted subthreshold rhythm. We additionally confirm these findings by using the FitzHugh-Nagumo excitable system as an alternative to the bistable overdamped oscillator

A YinYang bipolar fuzzy cognitive TOPSIS method to bipolar disorder diagnosis.

Science.gov (United States)

Han, Ying; Lu, Zhenyu; Du, Zhenguang; Luo, Qi; Chen, Sheng

2018-05-01

Bipolar disorder is often mis-diagnosed as unipolar depression in the clinical diagnosis. The main reason is that, different from other diseases, bipolarity is the norm rather than exception in bipolar disorder diagnosis. YinYang bipolar fuzzy set captures bipolarity and has been successfully used to construct a unified inference mathematical modeling method to bipolar disorder clinical diagnosis. Nevertheless, symptoms and their interrelationships are not considered in the existing method, circumventing its ability to describe complexity of bipolar disorder. Thus, in this paper, a YinYang bipolar fuzzy multi-criteria group decision making method to bipolar disorder clinical diagnosis is developed. Comparing with the existing method, the new one is more comprehensive. The merits of the new method are listed as follows: First of all, multi-criteria group decision making method is introduced into bipolar disorder diagnosis for considering different symptoms and multiple doctors' opinions. Secondly, the discreet diagnosis principle is adopted by the revised TOPSIS method. Last but not the least, YinYang bipolar fuzzy cognitive map is provided for the understanding of interrelations among symptoms. The illustrated case demonstrates the feasibility, validity, and necessity of the theoretical results obtained. Moreover, the comparison analysis demonstrates that the diagnosis result is more accurate, when interrelations about symptoms are considered in the proposed method. In a conclusion, the main contribution of this paper is to provide a comprehensive mathematical approach to improve the accuracy of bipolar disorder clinical diagnosis, in which both bipolarity and complexity are considered. Copyright © 2018 Elsevier B.V. All rights reserved.

Bipolar magnetic semiconductor in silicene nanoribbons

International Nuclear Information System (INIS)

Farghadan, Rouhollah

2017-01-01

Highlights: • A new electronic phase for silicene nanoribbon in the presence of electric and magnetic fields. • Bipolar magnetic semiconductor with controllable spin-flip and spin-conserved gaps in silicene. • Robust bipolar magnetic semiconductor features in a rough silicene. • Perfect and reversible spin polarization in silicene nanoribbon junctions. - Abstract: A theoretical study was presented on generation of spin polarization in silicene nanoribbons using the single-band tight-binding approximation and the non-equilibrium Green’s function formalism. We focused on the effect of electric and exchange magnetic fields on the spin-filter capabilities of zigzag-edge silicene nanoribbons in the presence of the intrinsic spin-orbit interaction. The results show that a robust bipolar magnetic semiconductor with controllable spin-flip and spin-conserved gaps can be obtained when exchange magnetic and electric field strengths are both larger than the intrinsic spin-orbit interaction. Therefore, zigzag silicene nanoribbons could act as bipolar and perfect spin filter devices with a large spin-polarized current and a reversible spin polarization in the vicinity of the Fermi energy. We also investigated the effect of edge roughness and found that the bipolar magnetic semiconductor features are robust against edge disorder in silicene nanoribbon junctions. These results may be useful in multifunctional spin devices based on silicene nanoribbons.

Bipolar magnetic semiconductor in silicene nanoribbons

Energy Technology Data Exchange (ETDEWEB)

Farghadan, Rouhollah, E-mail: rfarghadan@kashanu.ac.ir

2017-08-01

Highlights: • A new electronic phase for silicene nanoribbon in the presence of electric and magnetic fields. • Bipolar magnetic semiconductor with controllable spin-flip and spin-conserved gaps in silicene. • Robust bipolar magnetic semiconductor features in a rough silicene. • Perfect and reversible spin polarization in silicene nanoribbon junctions. - Abstract: A theoretical study was presented on generation of spin polarization in silicene nanoribbons using the single-band tight-binding approximation and the non-equilibrium Green’s function formalism. We focused on the effect of electric and exchange magnetic fields on the spin-filter capabilities of zigzag-edge silicene nanoribbons in the presence of the intrinsic spin-orbit interaction. The results show that a robust bipolar magnetic semiconductor with controllable spin-flip and spin-conserved gaps can be obtained when exchange magnetic and electric field strengths are both larger than the intrinsic spin-orbit interaction. Therefore, zigzag silicene nanoribbons could act as bipolar and perfect spin filter devices with a large spin-polarized current and a reversible spin polarization in the vicinity of the Fermi energy. We also investigated the effect of edge roughness and found that the bipolar magnetic semiconductor features are robust against edge disorder in silicene nanoribbon junctions. These results may be useful in multifunctional spin devices based on silicene nanoribbons.

Frequency of pacemaker malfunction associated with monopolar electrosurgery during pulse generator replacement or upgrade surgery.

Science.gov (United States)

Lin, Yun; Melby, Daniel P; Krishnan, Balaji; Adabag, Selcuk; Tholakanahalli, Venkatakrishna; Li, Jian-Ming

2017-08-01

The aim of this study is to investigate the frequency of electrosurgery-related pacemaker malfunction. A retrospective study was conducted to investigate electrosurgery-related pacemaker malfunction in consecutive patients undergoing pulse generator (PG) replacement or upgrade from two large hospitals in Minneapolis, MN between January 2011 and January 2014. The occurrence of this pacemaker malfunction was then studied by using MAUDE database for all four major device vendors. A total of 1398 consecutive patients from 2 large tertiary referral centers in Minneapolis, MN undergoing PG replacement or upgrade surgery were retrospectively studied. Four patients (0.3% of all patients), all with pacemakers from St Jude Medical (2.8%, 4 of 142) had output failure or inappropriately low pacing rate below 30 bpm during electrosurgery, despite being programmed in an asynchronous mode. During the same period, 1174 cases of pacemaker malfunctions were reported on the same models in MAUDE database, 37 of which (3.2%) were electrosurgery-related. Twenty-four cases (65%) had output failure or inappropriate low pacing rate. The distribution of adverse events was loss of pacing (59.5%), reversion to backup pacing (32.4%), inappropriate low pacing rate (5.4%), and ventricular fibrillation (2.7%). The majority of these (78.5%) occurred during PG replacement at ERI or upgrade surgery. No electrosurgery-related malfunction was found in MAUDE database on 862 pacemaker malfunction cases during the same period from other vendors. Electrosurgery during PG replacement or upgrade surgery can trigger output failure or inappropriate low pacing rate in certain models of modern pacemakers. Cautions should be taken for pacemaker-dependent patients.

Saline-enhanced hepatic radiofrequency ablation using a perfused-cooled electrode: comparison of dual probe bipolar mode with monopolar and single probe bipolar modes

International Nuclear Information System (INIS)

Lee, Jeong Min; Han, Joon Koo; Kim, Se Hyung; Lee, Jae Young; Kim, Dae Jin; Lee, Min Woo; Cho, Gyung Goo; Han, Chang Jin; Choi, Byung Ihn

2004-01-01

To determine whether saline-enhanced dual probe bipolar radiofrequency ablation (RFA) using perfused-cooled electrodes shows better in-vitro efficiency than monopolar or single probe bipolar RFA in creating larger coagulation necrosis. RF was applied to excised bovine livers in both bipolar and monopolar modes using a 200W generator (CC-3; Radionics) and the perfused-cooled electrodes for 10 mins. After placing single or double perfused-cooled electrodes in the explanted liver, 30 ablation zones were created at three different regimens: group A; saline-enhanced monopolar RFA, group B; saline-enhanced single probe bipolar RFA, and group C; saline-enhanced dual probe bipolar RFA. During RFA, we measured the tissue temperature at 15mm from the electrode. The dimensions of the ablation zones and changes in the impedance currents and liver temperature during RFA were then compared between the groups. The mean current values were higher for monopolar mode (group A) than for the bipolar modes (group B and C): 1550 ± 25 mA in group A, 764 ±189 mA in group B and 819 ± 98 mA in group C(ρ 3 in group A, 23.7 ±3.8 cm 3 in group B, and 34.2 ± 5.1 cm 3 in group C(ρ 0.05). The temperature at 15 mm from the electrode was higher in group C than in the other groups: 70 ± 18 .deg. C in group A, 59 ± 23 .deg. C in group B and 96 ± 16 .deg. C in group C (ρ < 0.05). Saline-enhanced bipolar RFA using dual perfused-cooled electrodes increases the dimension of the ablation zone more efficiently than monopolar RFA or single probe bipolar RFA

The Bipolar Interactive Psychoeducation (BIPED study: trial design and protocol

Directory of Open Access Journals (Sweden)

Jones Ian

2009-08-01

Full Text Available Abstract Background Bipolar disorders affect between 3–5% of the population and are associated with considerable lifelong impairment. Since much of the morbidity associated with bipolar disorder is caused by recurrent depressive symptoms, which are often only poorly responsive to antidepressants, there is a need to develop alternative, non-pharmacological interventions. Psychoeducational interventions have emerged as promising long-term therapeutic options for bipolar disorder. Methods/design The study is an exploratory, individually randomised controlled trial. The intervention known as 'Beating Bipolar' is a psychoeducational programme which is delivered via a novel web-based system. We will recruit 100 patients with a diagnosis of DSM-IV bipolar disorder (including type I and type II currently in clinical remission. The primary outcome is quality of life. This will be compared for those patients who have participated in the psychoeducational programme with those who received treatment as usual. Quality of life will be assessed immediately following the intervention as well as 10 months after randomisation. Secondary outcomes include current depressive and manic symptoms, number of episodes of depression and mania/hypomania experienced during the follow-up period, global functioning, functional impairment and insight. An assessment of costs and a process evaluation will also be conducted which will explore the feasibility and acceptability of the intervention as well as potential barriers to effectiveness. Discussion Bipolar disorder is common, under-recognised and often poorly managed. It is a chronic, life-long, relapsing condition which has an enormous impact on the individual and the economy. This trial will be the first to explore the effectiveness of a novel web-based psychoeducational intervention for patients with bipolar disorder which has potential to be easily rolled out to patients. Trial registration Current Controlled Trials

Tritium separation from light and heavy water by bipolar electrolysis

International Nuclear Information System (INIS)

Ramey, D.W.; Petek, M.; Taylor, R.D.; Kobisk, E.H.; Ramey, J.; Sampson, C.A.

1979-10-01

Use of bipolar electrolysis with countercurrent electrolyte flow to separate hydrogen isotopes was investigated for the removal of tritium from light water effluents or from heavy water moderator. Deuterium-tritium and protium-tritium separation factors occurring on a Pd-25% Ag bipolar electrode were measured to be 2.05 to 2.16 and 11.6 to 12.4 respectively, at current densities between 0.21 and 0.50 A cm -2 , and at 35 to 90 0 C. Current densities up to 0.3 A cm -2 have been achieved in continuous operation, at 80 to 90 0 C, without significant gas formation on the bipolar electrodes. From the measured overvoltage at the bipolar electrodes and the electrolyte conductivity the power consumption per stage was calculated to be 3.0 kwh/kg H 2 O at 0.2 A cm -2 and 5.0 kwh/kg H 2 O at 0.5 A cm -2 current density, compared to 6.4 and 8.0 kwh/kg H 2 O for normal electrolysis. A mathematical model derived for hydrogen isotope separation by bipolar electrolysis, i.e., for a square cascade, accurately describes the results for protium-tritium separation in two laboratory scale, multistage experiments with countercurrent electrolyte flow; the measured tiritum concentration gradient through the cascade agreed with the calculated values

SU-E-T-802: Verification of Implanted Cardiac Pacemaker Doses in Intensity-Modulated Radiation Therapy: Dose Prediction Accuracy and Reduction Effect of a Lead Sheet

Energy Technology Data Exchange (ETDEWEB)

Lee, J [Dept. of Radiation Oncology, Konkuk University Medical Center, Seoul (Korea, Republic of); Chung, J [Dept. of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

2015-06-15

Purpose: To verify delivered doses on the implanted cardiac pacemaker, predicted doses with and without dose reduction method were verified using the MOSFET detectors in terms of beam delivery and dose calculation techniques in intensity-modulated radiation therapy (IMRT). Methods: The pacemaker doses for a patient with a tongue cancer were predicted according to the beam delivery methods [step-and-shoot (SS) and sliding window (SW)], intensity levels for dose optimization, and dose calculation algorithms. Dosimetric effects on the pacemaker were calculated three dose engines: pencil-beam convolution (PBC), analytical anisotropic algorithm (AAA), and Acuros-XB. A lead shield of 2 mm thickness was designed for minimizing irradiated doses to the pacemaker. Dose variations affected by the heterogeneous material properties of the pacemaker and effectiveness of the lead shield were predicted by the Acuros-XB. Dose prediction accuracy and the feasibility of the dose reduction strategy were verified based on the measured skin doses right above the pacemaker using mosfet detectors during the radiation treatment. Results: The Acuros-XB showed underestimated skin doses and overestimated doses by the lead-shield effect, even though the lower dose disagreement was observed. It led to improved dose prediction with higher intensity level of dose optimization in IMRT. The dedicated tertiary lead sheet effectively achieved reduction of pacemaker dose up to 60%. Conclusion: The current SS technique could deliver lower scattered doses than recommendation criteria, however, use of the lead sheet contributed to reduce scattered doses.Thin lead plate can be a useful tertiary shielder and it could not acuse malfunction or electrical damage of the implanted pacemaker in IMRT. It is required to estimate more accurate scattered doses of the patient with medical device to design proper dose reduction strategy.

SU-E-T-802: Verification of Implanted Cardiac Pacemaker Doses in Intensity-Modulated Radiation Therapy: Dose Prediction Accuracy and Reduction Effect of a Lead Sheet

International Nuclear Information System (INIS)

Lee, J; Chung, J

2015-01-01

Purpose: To verify delivered doses on the implanted cardiac pacemaker, predicted doses with and without dose reduction method were verified using the MOSFET detectors in terms of beam delivery and dose calculation techniques in intensity-modulated radiation therapy (IMRT). Methods: The pacemaker doses for a patient with a tongue cancer were predicted according to the beam delivery methods [step-and-shoot (SS) and sliding window (SW)], intensity levels for dose optimization, and dose calculation algorithms. Dosimetric effects on the pacemaker were calculated three dose engines: pencil-beam convolution (PBC), analytical anisotropic algorithm (AAA), and Acuros-XB. A lead shield of 2 mm thickness was designed for minimizing irradiated doses to the pacemaker. Dose variations affected by the heterogeneous material properties of the pacemaker and effectiveness of the lead shield were predicted by the Acuros-XB. Dose prediction accuracy and the feasibility of the dose reduction strategy were verified based on the measured skin doses right above the pacemaker using mosfet detectors during the radiation treatment. Results: The Acuros-XB showed underestimated skin doses and overestimated doses by the lead-shield effect, even though the lower dose disagreement was observed. It led to improved dose prediction with higher intensity level of dose optimization in IMRT. The dedicated tertiary lead sheet effectively achieved reduction of pacemaker dose up to 60%. Conclusion: The current SS technique could deliver lower scattered doses than recommendation criteria, however, use of the lead sheet contributed to reduce scattered doses.Thin lead plate can be a useful tertiary shielder and it could not acuse malfunction or electrical damage of the implanted pacemaker in IMRT. It is required to estimate more accurate scattered doses of the patient with medical device to design proper dose reduction strategy

Cognitive and functional deficits in bipolar disorder and schizophrenia as a function of the presence and history of psychosis.

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Bowie, Christopher R; Best, Michael W; Depp, Colin; Mausbach, Brent T; Patterson, Thomas L; Pulver, Ann E; Harvey, Philip D

2018-05-18

Schizophrenia and bipolar disorder overlap considerably. Schizophrenia is a primary psychotic disorder, whereas approximately half of people with bipolar disorder will experience psychosis. In this study, we examined the extent to which cognitive and functional impairments are related to the presence and history of psychosis across the two disorders. A total of 633 participants with bipolar disorder I, schizophrenia, and schizoaffective disorder were recruited for a study on the genetics of cognition and functioning in bipolar disorder and schizophrenia. Participants were classified into five groups: bipolar disorder with current psychosis (N = 30), bipolar disorder with a history of psychosis (N = 162), bipolar disorder with no history of psychosis (N = 92), schizophrenia with current psychosis (N = 245), and schizophrenia with past psychosis (N = 104). Cognitive profiles of all groups were similar in pattern; however, both current psychosis (P bipolar disorder and schizophrenia experienced similar impairments in real-world functioning if they were experiencing current psychosis (P = .32). The presence of active psychosis is an important cross-diagnostic factor in cognition and functioning in both schizophrenia and bipolar disorder. Characterization and treatment of cognition and functional deficits in bipolar disorder should consider the effects of both current and history of psychosis. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Pacemaker replacement in nonagenarians: Procedural safety and long-term follow-up.

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Loirat, Aurélie; Fénéon, Damien; Behaghel, Albin; Behar, Nathalie; Le Helloco, Alain; Mabo, Philippe; Daubert, Jean-Claude; Leclercq, Christophe; Martins, Raphaël P

2015-01-01

The rate of pacemaker implantation is rising. Given that the life expectancy of the population is projected to increase, a large number of elderly patients are likely to be implanted in the future. As pacemaker batteries can last for 8-10years, an increasing number of pacemaker recipients will require replacement of their devices when they become nonagenarians. To analyse the short- and long-term outcomes after device replacement in nonagenarians. Patients aged≥90years referred to a tertiary centre for pacemaker replacement from January 2004 to July 2014 were included retrospectively. Clinical follow-up data were obtained from clinical visits or telephone interviews with patients or their families. The primary clinical endpoint was total mortality. Secondary endpoints included early and delayed procedure-related complications and predictive risk factors for total mortality. Sixty-two patients were included (mean age 93.3±2.9years at time of pacemaker replacement). Mean procedure duration was 35.7±17.2minutes. Mean hospital stay was 2.2±1.1days. One patient died from a perioperative complication. Thirty-seven patients (59.7%) died during a median follow-up of 22.1months (interquartile range, 11.8-39.8months). Survival rates were 84.2% (95% confidence interval [CI] 71.8-91.5%) at 1year, 66.9% (95% CI 51.8-78.2%) at 2years and 22.7% (95% CI 10.6-37.7%) at 5years. Atrial fibrillation (hazard ratio 2.47, 95% CI 1.1-5.6) and non-physiological pacing (i.e. VVI pacing in patients in sinus rhythm) (hazard ratio 2.20, 95% CI 1.0-4.9) were predictors of mortality. Pacemaker replacement in nonagenarians is a safe and straightforward procedure. These data suggest that procedures can be performed securely in this old and frail population, with patients living for a median of 30months afterwards. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Influence of ionizing radiation on the probability of failure of long-term pacemakers

Energy Technology Data Exchange (ETDEWEB)

Eger, H.; Hesse, W.; Otte, K.B.; Rauh, G.; Salewski, D.; Stopp, G. (Zentralklinik fuer Herz- und Lungenkrankheiten, Bad Berka (German Democratic Republic); VEB Transformatoren- und Roentgenwerk ' Hermann Matern' Dresden (German Democratic Republic); Martin-Luther-Universitaet Halle-Wittenberg, Halle (German Democratic Republic). Radiologische Klinik; Staatliches Amt fuer Atomsicherheit und Strahlenschutz, Berlin (German Democratic Republic))

1982-11-01

The functional disturbances observed during the exposure of cardiac pacemakers with a CMOS switching circle U 115 are described qualitatively for different types of radiation. Based on the maximum sensitivity of the U 115 within the X-ray range, the correlation for this range between dose of exposure and parameter changes is established. As is demonstrated such changes is established. As is demonstrated such changes are not clinically relevant as long as the dose of 5,16 x 10/sup -2/ C/kg is not exceeded. Proceeding from the accumulated dose to which the U 115 is exposed during various diagnostic radiographic procedures it is shown that such procedures do not result in functional disturbances of the pacemaker. Recommendations are given for radiotherapeutic measures as to pacemaker patients, which should be realized in close co-operation between the pacemaker centre concerned and an authorized hospital.

Cardiac MRI in patients with complex CHD following primary or secondary implantation of MRI-conditional pacemaker system.

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Al-Wakeel, Nadya; O h-Ici, Darach; Schmitt, Katharina R; Messroghli, Daniel R; Riesenkampff, Eugénie; Berger, Felix; Kuehne, Titus; Peters, Bjoern

2016-02-01

In patients with CHD, cardiac MRI is often indicated for functional and anatomical assessment. With the recent introduction of MRI-conditional pacemaker systems, cardiac MRI has become accessible for patients with pacemakers. The present clinical study aims to evaluate safety, susceptibility artefacts, and image reading of cardiac MRI in patients with CHD and MRI-conditional pacemaker systems. Material and methods CHD patients with MRI-conditional pacemaker systems and a clinical need for cardiac MRI were examined with a 1.5-T MRI system. Lead function was tested before and after MRI. Artefacts and image readings were evaluated using a four-point grading scale. A total of nine patients with CHD (mean age 34.0 years, range 19.5-53.6 years) received a total of 11 cardiac MRI examinations. Owing to clinical indications, seven patients had previously been converted from conventional to MRI-conditional pacemaker systems. All MRI examinations were completed without adverse effects. Device testing immediately after MRI and at follow-up showed no alteration of pacemaker device and lead function. Clinical questions could be addressed and answered in all patients. Cardiac MRI can be performed safely with high certainty of diagnosis in CHD patients with MRI-conditional pacemaker systems. In case of clinically indicated lead and box changing, CHD patients with non-MRI-conditional pacemaker systems should be considered for complete conversion to MRI-conditional systems.

Electroconvulsive therapy in patients with cardiac pacemakers and implantable cardioverter defibrillators.

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Dolenc, Tamara J; Barnes, Roxann D; Hayes, David L; Rasmussen, Keith G

2004-09-01

Electroconvulsive therapy (ECT) is used to treat major depressive illness, especially in elderly and medically frail patients. Not uncommonly, these patients have cardiac pacemakers or implantable cardioverter defibrillators (ICDs). Only a few case reports in the literature describe the use of ECT in such patients. Herein we review our ECT experience treating 26 pacemaker patients and 3 ICD patients. All patients obtained significant antidepressant benefits with ETC. Only one serious cardiac event occurred, a case of supraventricular tachycardia (SVT) requiring a stay on the cardiac intensive care unit. The SVT resolved and the patient went on to receive further uncomplicated ECT treatments. We conclude from this experience that with proper pre-ECT cardiac and pacemaker/defibrillator assessment, ECT can be safely and effectively administered to patients with an implanted cardiac device.

Bipolar disorders

DEFF Research Database (Denmark)

Vieta, Eduard; Berk, Michael; Schulze, Thomas G

2018-01-01

Bipolar disorders are chronic and recurrent disorders that affect >1% of the global population. Bipolar disorders are leading causes of disability in young people as they can lead to cognitive and functional impairment and increased mortality, particularly from suicide and cardiovascular disease...... and accurate diagnosis is difficult in clinical practice as the onset of bipolar disorder is commonly characterized by nonspecific symptoms, mood lability or a depressive episode, which can be similar in presentation to unipolar depression. Moreover, patients and their families do not always understand...... a bipolar disorder from other conditions. Optimal early treatment of patients with evidence-based medication (typically mood stabilizers and antipsychotics) and psychosocial strategies is necessary....

Incidence of Bradycardia and Outcomes of Patients Who Underwent Orbital Atherectomy Without a Temporary Pacemaker.

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Lee, Michael S; Nguyen, Heajung; Shlofmitz, Richard

2017-02-01

We analyzed the incidence of bradycardia and the safety of patients with severely calcified coronary lesions who underwent orbital atherectomy without the insertion of a temporary pacemaker. The presence of severely calcified coronary lesions can increase the complexity of percutaneous coronary intervention due to the difficulty in advancing and optimally expanding the stent. High-pressure inflations to predilate calcified lesions may cause angiographic complications like perforation and dissection. Suboptimal stent expansion is associated with stent thrombosis and restenosis. Orbital atherectomy safely and effectively modifies calcified plaque to facilitate optimal stent expansion. The incidence of bradycardia in orbital atherectomy is unknown. Fifty consecutive patients underwent orbital atherectomy from February 2014 to September 2016 at our institution, none of whom underwent insertion of a temporary pacemaker. The final analysis included 47 patients in this retrospective study as 3 patients were excluded because of permanent pacemaker implantation. The primary endpoint was significant bradycardia, defined as bradycardia requiring emergent pacemaker placement or a heart rate pacemaker appears to be safe.

Attentional biases for emotional facial stimuli in currently depressed patients with bipolar disorder

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Lemke Leyman

2009-01-01

Full Text Available En comparación con las numerosas investigaciones centradas en los factores de vulnerabilidad cognitiva que subyacen en el inicio y el desarrollo del trastorno depresivo mayor, los estudios que investigan el procesamiento disfuncional de la información emocional en el trastorno bipolar siguen siendo escasos. Por ello, el presente estudio experimental ha analizado la naturaleza y el curso temporal de los sesgos atencionales en pacientes depresivos con trastorno bipolar. Un total de catorce pacientes deprimidos con Trastorno Bipolar I (TB y catorce participantes controles no deprimidos (CN, emparejados en edad, sexo y nivel educativo, realizaron una modificación emocional de la tarea de señalización espacial. Las señales consistían en expresiones faciales de enfado, neutrales y positivas presentadas durante 200 y 1.000 ms. Los pacientes con TB mostraron un mayor efecto de validación de las señales en las caras de enfado y presentaron más dificultades a la hora de desvincular la atención de las expresiones faciales de enfado y de alegría en comparación con los participantes CN, que por el contrario, demostraron un «sesgo protector» distanciado de la información negativa. Este patrón diferenciado de procesamiento atencional solo se halló en la fase inicial del procesamiento de la información en una presentación de 200 ms de duración. Estos resultados demuestran la existencia de déficits en las fases iniciales del procesamiento atencional de la información emocional en pacientes deprimidos bipolares en comparación con los controles sanos.

The effects of ionizing radiation on eight cardiac pacemakers and the influence of electromagnetic interference from two linear accelerators

International Nuclear Information System (INIS)

Venselaar, J.L.M.

1985-01-01

Eight cardiac pacemakers were irradiated in a cobalt-60 beam. Two out of six demand-type pacemakers showed an alarming decrease in pulse repetition frequency when irradiated to dose levels that are used in radiotherapy. Two modern programmable pacemakers showed a failure at a dose of 97 and 147 Gy, respectively. The dose levels at which these failures occurred were low enough to recommend that cardiac pacemakers should always be kept outside the radiation beam. The signals induced by electromagnetic interference (EMI) from two linear accelerators were measured using a simulation model of a pacemaker. In the laboratory, 22 modern-type pacemakers were tested with these signals to determine the sensitivity for the electromagnetic fields in the treatment rooms. It was observed that an inhibition of one pacemaker pulse was to be expected on one of the two linear accelerators when switching the machine on and off. No permanent effects were found. These findings resulted in the recommendation in our department not to use this treatment machine for radiation therapy of pacemaker-bearing patients. (orig.)

Electronic monitoring in bipolar disorder.

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Faurholt-Jepsen, Maria

2018-03-01

Major reasons for the insufficient effects of current treatment options in bipolar disorder include delayed intervention for prodromal depressive and manic symptoms and decreased adherence to psychopharmacological treatment. The reliance on subjective information and clinical evaluations when diagnosing and assessing the severity of depressive and manic symptoms calls for less biased and more objective markers. By using electronic devices, fine-grained data on complex psychopathological aspects of bipolar disorder can be evaluated unobtrusively over the long term. Moreover, electronic data could possibly represent candidate markers of diagnosis and illness activity in bipolar disorder and allow for early and individualized intervention for prodromal symptoms outside clinical settings. 
The present dissertation concerns the use of electronic monitoring as a marker and treatment intervention in bipolar disorder and investigated the scientific literature and body of evidence within the area, which includes ten original study reports and two systematic reviews, one of which included a meta-analysis, conducted by the author of the dissertation. 
Taken together, the literature presented in this dissertation illustrates that 1) smartphone-based electronic self-monitoring of mood seems to reflect clinically assessed depressive and manic symptoms and enables the long-term characterization of mood

instability in bipolar disorder; 2) preliminary results suggest that smartphone-based automatically generated data (e.g. the number of text messages sent/day; the number of incoming and outgoing calls/day; the number of changes in cell tower IDs/day; and voice features) seem to reflect clinically assessed depressive and manic symptoms in bipolar disorder; 3) smartphone-based electronic self-monitoring had no effects on the severity of depressive and manic symptoms in bipolar disorder, according to a randomized controlled trial; and 4) electronic monitoring of psychomotor

Ways and means to check on a patient wearing a cardiac pacemaker

International Nuclear Information System (INIS)

Marco, J.; Couderc, J.-J.; Salvador, M.; Dardenne, P.

1975-01-01

The implantation of present-day pacemakers with improved mercury batteries, undoubtedly increasing life expectancy and safety, or of new nuclear or lithium-battery pacemakers, will change the check-up frequency and delay prophylactic replacement operations. Similarly the developing possibilities of the telephone check-up, which offers a reliable long-distance analysis of the different parameters stated, will simplify the organization of these specialized consultations which are a heavy burden for cardiological Services fitting pacemakers and oblige patients to make special journeys, sometimes difficult and even impossible in certain cases. However a knowledge of these different factors by all practising doctors and cardiologists now seems indispensable for the safety of these increasingly numerous patients [fr

PEMFC Performance with Metal Bipolar Plates Depending on the Channel Dimension

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Kwon Kuikam

2016-01-01

Full Text Available Bipolar plates of a proton exchange membrane fuel cell (PEMFC play an important role in removing liquid phase water as a by-product in order to facilitate the reaction between fuel and oxygen. A great amount of effort has been made to improve the performance of a fuel cell such as maximum current density or maximum power, by improving water removability of a bipolar plate. Most of the studies, however, are conducted numerically because of the complexity of analysing gas and liquid and the poor manufacturability of graphite bipolar plates. In this proceeding, we demonstrate that the performance of a PEMFC with metal bipolar plates can be enhanced by reducing the dimension of the channel. Bipolar plates were machined with stainless steel (type 316L to have three different channel size (1000 μm, 500 μm and 300 μm and the performance of each assembled cells were tested. As a result, the maximum power density and the maximum current density increased by 25%.

Neutrality in bipolar structures

DEFF Research Database (Denmark)

Montero, Javier; Rodríguez, J. Tinguaro; Franco, Camilo

2014-01-01

In this paper, we want to stress that bipolar knowledge representation naturally allows a family of middle states which define as a consequence different kinds of bipolar structures. These bipolar structures are deeply related to the three types of bipolarity introduced by Dubois and Prade, but our...... approach offers a systematic explanation of how such bipolar structures appear and can be identified....

Positive Traits in the Bipolar Spectrum: The Space between Madness and Genius

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Greenwood, Tiffany A.

2017-01-01

Bipolar disorder is a severe, lifelong mood disorder for which little is currently understood of the genetic mechanisms underlying risk. By examining related dimensional phenotypes, we may further our understanding of the disorder. Creativity has a historical connection with the bipolar spectrum and is particularly enhanced among unaffected first-degree relatives and those with bipolar spectrum traits. This suggests that some aspects of the bipolar spectrum may confer advantages, while more severe expressions of symptoms negatively influence creative accomplishment. Creativity is a complex, multidimensional construct with both cognitive and affective components, many of which appear to reflect a shared genetic vulnerability with bipolar disorder. It is suggested that a subset of bipolar risk variants confer advantages as positive traits according to an inverted-U-shaped curve with clinically unaffected allele carriers benefitting from the positive traits and serving to maintain the risk alleles in the population. The association of risk genes with creativity in healthy individuals (e.g., NRG1), as well as an overall sharing of common genetic variation between bipolar patients and creative individuals, provides support for this model. Current findings are summarized from a multidisciplinary perspective to demonstrate the feasibility of research in this area to reveal the mechanisms underlying illness. PMID:28277566

Evaluation of Safety and Efficacy of Qinming8631 DR Implantable Cardiac Pacemaker in Chinese Patients: A Prospective, Multicenter, Randomized Controlled Trial of the First Domestically Developed Pacemaker of China.

Science.gov (United States)

Xiang, Mei-Xiang; Wang, Dong-Qi; Xu, Jing; Zhang, Zheng; Hu, Jian-Xin; Wang, Dong-Mei; Gu, Xiang; Liu, He-Ping; Guo, Tao; Yang, Xiang-Jun; Ling, Feng; Lin, Jia-Feng; Cai, Shang-Lang; Zhu, Guo-Bin; Wang, Jian-An

2016-11-20

High cost of imported pacemakers is a main obstacle for Chinese patients suffering from bradyarrhythmia, and a domestically developed pacemaker will help lower the burden. This study aimed to evaluate the safety and efficacy of Qinming8631 DR (Qinming Medical, Baoji, China), the first domestically developed dual-chamber pacemaker of China, compared with a commercially available pacemaker Talos DR (Biotronik, Berlin, Germany) in Chinese patients. A prospective randomized trial was conducted at 14 centers in China. Participants were randomized into trial (Qinming8631 DR) and control (Talos DR) groups. Parameters of the pacing systems were collected immediately after device implantation and during follow-ups. The effective pacing rate at 6-month follow-up was recorded as the primary end point. Electrical properties, magnet response, single- and double-pole polarity conversion, rate response function, and adverse events of the pacing system were analyzed. The Cochran-Mantel-Haenszel Chi-square test, paired t-test, and Wilcoxon signed-rank test were used for measuring primary qualitative outcomes and comparing normally and abnormally distributed measurement data. A total of 225 patients with a diagnosis of bradyarrhythmia and eligible for this study were randomly enrolled into the trial (n = 113) and control (n = 112) groups. They underwent successful pacemaker implantation with acceptable postoperative pacing threshold and sensitivity. Effective pacing rates of trial and control groups were comparable both in the full analysis set and the per protocol set (81.4% vs. 79.5%, P = 0.712 and 95.4% vs. 89.5%, P = 0.143, respectively). In both data sets, noninferiority of the trial group was above the predefined noninferiority limit(-9.5%). This study established the noninferiority of Qinming8631 DR to Talos DR. The safety and efficacy of Qinming8631 DR pacemaker were comparable to those of Talos DR in treating patients with cardiac bradyarrhythmia.

Monitoring the radiation dose to a multiprogrammable pacemaker during radical radiation therapy: A case report

International Nuclear Information System (INIS)

Muller-Runkel, R.; Orsolini, G.; Kalokhe, U.P.

1990-01-01

Multiprogrammable pacemakers, using complimentary metaloxide semiconductor (CMOS) circuitry, may fail during radiation therapy. We report about a patient who received 6,400 cGy for unresectable carcinoma of the left lung. In supine treatment position, arms raised above the head, the pacemaker was outside the treated area by a margin of at least 1 cm, shielded by cerrobend blocking mounted on a tray. From thermoluminescent dosimeter (TLD) measurements, we estimate that the pacemaker received 620 cGy in scatter doses. Its function was monitored before, during, and after completion of radiation therapy. The pacemaker was functioning normally until the patient's death 5 months after completion of treatment. The relevant electrocardiograms (ECGs) are presented

Metabolic syndrome in subjects with bipolar disorder and major depressive disorder in a current depressive episode: Population-based study: Metabolic syndrome in current depressive episode.

Science.gov (United States)

Moreira, Fernanda Pedrotti; Jansen, Karen; Cardoso, Taiane de Azevedo; Mondin, Thaíse Campos; Magalhães, Pedro Vieira da Silva; Kapczinski, Flávio; Souza, Luciano Dias de Mattos; da Silva, Ricardo Azevedo; Oses, Jean Pierre; Wiener, Carolina David

2017-09-01

To assess the differences in the prevalence of the metabolic syndrome (MetS) and their components in young adults with bipolar disorder (BD) and major depressive disorder (MDD) in a current depressive episode. This was a cross-sectional study with young adults aged 24-30 years old. Depressive episode (bipolar or unipolar) was assessed using the Mini International Neuropsychiatric Interview - Plus version (MINI Plus). The MetS was assessed using the National Cholesterol Education Program Adult Treatment Panel III (NCEP/ATP III). The sample included 972 subjects with a mean age of 25.81 (±2.17) years. Both BD and MDD patients showed higher prevalence of MetS compared to the population sample (BD = 46.9%, MDD = 35.1%, population = 22.1%, p depressive episode compared to the general population. Moreover, there was a significant difference on BMI values in the case of BD and MDD subjects (p = 0.016). Metabolic components were significantly associated with the presence of depressive symptoms, independently of the diagnosis. Copyright © 2017. Published by Elsevier Ltd.

Enhancement of Spontaneous Activity by HCN4 Overexpression in Mouse Embryonic Stem Cell-Derived Cardiomyocytes - A Possible Biological Pacemaker.

Directory of Open Access Journals (Sweden)

Yukihiro Saito

Full Text Available Establishment of a biological pacemaker is expected to solve the persisting problems of a mechanical pacemaker including the problems of battery life and electromagnetic interference. Enhancement of the funny current (If flowing through hyperpolarization-activated cyclic nucleotide-gated (HCN channels and attenuation of the inward rectifier K+ current (IK1 flowing through inward rectifier potassium (Kir channels are essential for generation of a biological pacemaker. Therefore, we generated HCN4-overexpressing mouse embryonic stem cells (mESCs and induced cardiomyocytes that originally show poor IK1 currents, and we investigated whether the HCN4-overexpressing mESC-derived cardiomyocytes (mESC-CMs function as a biological pacemaker in vitro.The rabbit Hcn4 gene was transfected into mESCs, and stable clones were selected. mESC-CMs were generated via embryoid bodies and purified under serum/glucose-free and lactate-supplemented conditions. Approximately 90% of the purified cells were troponin I-positive by immunostaining. In mESC-CMs, expression level of the Kcnj2 gene encoding Kir2.1, which is essential for generation of IK1 currents that are responsible for stabilizing the resting membrane potential, was lower than that in an adult mouse ventricle. HCN4-overexpressing mESC-CMs expressed about a 3-times higher level of the Hcn4 gene than did non-overexpressing mESC-CMs. Expression of the Cacna1h gene, which encodes T-type calcium channel and generates diastolic depolarization in the sinoatrial node, was also confirmed. Additionally, genes required for impulse conduction including Connexin40, Connexin43, and Connexin45 genes, which encode connexins forming gap junctions, and the Scn5a gene, which encodes sodium channels, are expressed in the cells. HCN4-overexpressing mESC-CMs showed significantly larger If currents and more rapid spontaneous beating than did non-overexpressing mESC-CMs. The beating rate of HCN4-overexpressing mESC-CMs responded

Analysis of a five year experience of permanent pacemaker implantation at a Nigerian Teaching Hospital: need for a national database

Science.gov (United States)

Falase, Bode; Sanusi, Michael; Johnson, Adeyemi; Akinrinlola, Fola; Ajayi, Reina; Oke, David

2013-01-01

Introduction Permanent pacemaker implantation is available in Nigeria. There is however no national registry or framework for pacemaker data collection. A pacemaker database has been developed in our institution and the results are analyzed in this study. Methods The study period was between January 2008 and December 2012. Patient data was extracted from a prospectively maintained database which was designed to include the fields of the European pacemaker patient identification code. Results Of the 51 pacemaker implants done, there were 29 males (56.9%) and 22 females (43.1%). Mean age was 68.2±12.7 years. Clinical indications were syncopal attacks in 25 patients (49%), dizzy spells in 15 patients (29.4%), bradycardia with no symptoms in 10 patients (17.7%) and dyspnoea in 2 patients (3.9%). The ECG diagnosis was complete heart block in 27 patients (53%), second degree heart block in 19 patients (37.2%) and sick sinus syndrome with bradycardia in 5 patients (9.8%). Pacemaker modes used were ventricular pacing in 29 patients (56.9%) and dual chamber pacing in 22 patients (43.1%). Files have been closed in 20 patients (39.2%) and 31 patients (60.8%) are still being followed up with median follow up of 26 months, median of 5 visits and 282 pacemaker checks done. Complications seen during follow up were 3 lead displacements (5.9%), 3 pacemaker infections (5.9%), 2 pacemaker pocket erosions (3.9%), and 1 pacemaker related death (2%). There were 5 non-pacemaker related deaths (9.8%). Conclusion Pacemaker data has been maintained for 5 years. We urge other implanting institutions in Nigeria to maintain similar databases and work towards establishment of a national pacemaker registry. PMID:24498465

Lateral n-p-n bipolar transistors by ion implantation into semi-insulating GaAs

International Nuclear Information System (INIS)

Canfield, P.; Forbes, L.

1988-01-01

GaAs bipolar transistors have not seen the major development effort that GaAs MESFETs have due primarily to the short minority carrier lifetimes in GaAs. The short minority carrier lifetimes require that the base region be very thin which, if done by implantation, requires that the doping be high to obtain a well defined base profile. These requirements are very difficult to achieve in GaAs and typically, if high current gain and high speed are desired for a bipolar technology, then heterostructure bipolars are the appropriate technology, although the cost of heterostructure devices will be prohibitive for some time to come. For applications requiring low current gain, more modest fabrication rules can be followed. Lateral bipolars are particularly attractive since they would be easier to fabricate than a planar bipolar or a heterojunction bipolar. Lateral bipolars do not require steps or deep contacts to make contact with the subcollector or highly doped very thin epilayers for the base region and they can draw upon the semi-insulating properties of the GaAs substrates for device isolation. Bipolar transistors are described and shown to work successfully. (author)

Short- and long-term need for permanent pacemaker after transcatheter implantation of the Edwards Sapien aortic valve prosthesis.

Science.gov (United States)

Moreno, Raúl; Calvo, Luis; Sánchez-Recalde, Angel; Galeote, Guillermo; Jiménez-Valero, Santiago; López, Teresa; Plaza, Ignacio; González-Davia, Rosa; Ramírez, Ulises; Mesa, Jose Maria; Moreno-Gomez, Isidro; López-Sendón, José-Luis

2015-11-01

A permanent pacemaker is frequently needed after transcatheter aortic valve implantation, but the available data are mainly on the CoreValve system. To evaluate the need for new permanent pacemaker after implantation of the Edwards Sapien device, as well as related factors. We included the first 100 patients treated with the Edwards Sapien device at our institution. Of these, 12 had a permanent pacemaker before the procedure, and thus our study population was the remaining 88 patients. A permanent pacemaker was indicated in eight patients (9.1%) during hospitalization or at 30 days. After discharge, another four patients needed a pacemaker (at 42 days and three, 18, and 30 months). Two variables were associated with the need for pacemaker during hospitalization: previous dialysis (13% vs. 1%, p=0.042) and complete right bundle branch block before the procedure (25% vs. 5%, p=0.032). More than one month after the procedure, the characteristics associated with the need for pacemaker were plasma creatinine level (2.5±1.7 vs. 1.3±0.6 mg/dl, p=0.001) and previous myocardial infarction (50% vs. 10%, p=0.013). The rate of pacemaker implantation with the Edwards Sapien device was 9.1%. Right bundle branch block and dialysis were associated with this complication.

Recovery of Ventriculo-Atrial Conduction after Adrenaline in Patients Implanted with Pacemakers.

Science.gov (United States)

Cismaru, Gabriel; Gusetu, Gabriel; Muresan, Lucian; Rosu, Radu; Andronache, Marius; Matuz, Roxana; Puiu, Mihai; Mester, Petru; Miclaus, Maria; Pop, Dana; Mircea, Petru Adrian; Zdrenghea, Dumitru

2015-07-01

Ventriculo-atrial (VA) conduction can have negative consequences for patients with implanted pacemakers and defibrillators. There is concern whether impaired VA conduction could recover during stressful situations. Although the influence of isoproterenol and atropine are well established, the effect of adrenaline has not been studied systematically. The objective of this study was to determine if adrenaline can facilitate recovery of VA conduction in patients implanted with pacemakers. A prospective study was conducted on 61 consecutive patients during a 4-month period (April-July 2014). The presence of VA conduction was assessed during the pacemaker implantation procedure. In case of an impaired VA conduction, adrenaline infusio was used as a stress surrogate to test conduction recovery. The indications for pacemaker implantation were: sinus node dysfunction in 18 patients, atrioventricular (AV) block in 40 patients, binodal dysfunction (sinus node+ AV node) in two patients and other (carotid sinus syndrome) in one patient. In the basal state, 15/61 (24.6%) presented spontaneous VA conduction and 46/61 (75.4%) had no VA conduction. After administration of adrenaline, there was VA conduction recovery in 5/46 (10.9%) patients. Adrenaline infusion produced recovery of VA conduction in 10.9% of patients with absent VA conduction in a basal state. Recovery of VA conduction during physiological or pathological stresses could be responsible for the pacemaker syndrome, PMT episodes, or certain implantable cardiac defibrillator detection issues. © 2015 Wiley Periodicals, Inc.

Conductivity-limiting bipolar thermal conductivity in semiconductors

Science.gov (United States)

Wang, Shanyu; Yang, Jiong; Toll, Trevor; Yang, Jihui; Zhang, Wenqing; Tang, Xinfeng

2015-01-01

Intriguing experimental results raised the question about the fundamental mechanisms governing the electron-hole coupling induced bipolar thermal conduction in semiconductors. Our combined theoretical analysis and experimental measurements show that in semiconductors bipolar thermal transport is in general a “conductivity-limiting” phenomenon, and it is thus controlled by the carrier mobility ratio and by the minority carrier partial electrical conductivity for the intrinsic and extrinsic cases, respectively. Our numerical method quantifies the role of electronic band structure and carrier scattering mechanisms. We have successfully demonstrated bipolar thermal conductivity reduction in doped semiconductors via electronic band structure modulation and/or preferential minority carrier scatterings. We expect this study to be beneficial to the current interests in optimizing thermoelectric properties of narrow gap semiconductors. PMID:25970560

Improving Treatment Adherence in Bipolar Disorder: A Review of Current Psychosocial Treatment Efficacy and Recommendations for Future Treatment Development

Science.gov (United States)

Gaudiano, Brandon A.; Weinstock, Lauren M.; Miller, Ivan W.

2008-01-01

Treatment adherence is a frequent problem in bipolar disorder, with research showing that more than 60% of bipolar patients are at least partially nonadherent to medications. Treatment nonadherence is consistently predictive of a number of negative outcomes in bipolar samples, and the discontinuation of mood stabilizers places these patients at…

Case study thoracic radiotherapy in an elderly patient with pacemaker: The issue of pacing leads

International Nuclear Information System (INIS)

Kirova, Youlia M.; Menard, Jean; Chargari, Cyrus; Mazal, Alejandro; Kirov, Krassen

2012-01-01

To assess clinical outcome of patients with pacemaker treated with thoracic radiation therapy for T8-T9 paravertebral chloroma. A 92-year-old male patient with chloroma presenting as paravertebral painful and compressive (T8-T9) mass was referred for radiotherapy in the Department of Radiation Oncology, Institut Curie. The patient presented with cardiac dysfunction and a permanent pacemaker that had been implanted prior. The decision of Multidisciplinary Meeting was to deliver 30 Gy in 10 fractions for reducing the symptoms and controlling the tumor growth. The patient received a total dose of 30 Gy in 10 fractions using 4-field conformal radiotherapy with 20-MV photons. The dose to pacemaker was 0.1 Gy but a part of the pacing leads was in the irradiation fields. The patient was treated the first time in the presence of his radiation oncologist and an intensive care unit doctor. Moreover, the function of his pacemaker was monitored during the entire radiotherapy course. No change in pacemaker function was observed during any of the radiotherapy fractions. The radiotherapy was very well tolerated without any side effects. The function of the pacemaker was checked before and after the radiotherapy treatment by the cardiologist and no pacemaker dysfunction was observed. Although updated guidelines are needed with acceptable dose criteria for implantable cardiac devices, it is possible to treat patients with these devices and parts encroaching on the radiation field. This case report shows we were able to safely treat our patient through a multidisciplinary approach, monitoring the patient during each step of the treatment.

Placement Of Cardiac PacemaKEr Trial (POCKET – rationale and design: a randomized controlled trial

Directory of Open Access Journals (Sweden)

Peter Magnusson

2017-04-01

Full Text Available BackgroundA pacemaker system consists of one or two leads connected to a device that is implanted into a pocket formed just below the collarbone. This pocket is typically subcutaneous, that is, located just above the pectoral fascia. Even though the size of pacemakers has decreased markedly, complications due to superficial implants do occur. An alternative technique would be intramuscular placement of the pacemaker device, but there are no randomized controlled trials (RCTs to support this approach, which is the rationale for the Placement Of Cardiac PacemaKEr Trial (POCKET. The aim is to study if intramuscular is superior to subcutaneous placement of a pacemaker pocket.MethodsIn October 2016, we started to enroll 200 consecutive patients with an indication for bradycardia pacemaker implantation. Patients are randomized to random block sizes, stratified by age group (cut-off: 65 years and sex, and then randomized to either subcutaneous or intramuscular implant. A concealed allocation procedure is employed, using sequentially numbered, sealed envelopes. Pocket site is blinded to the patient and in all subsequent care. The primary endpoint is patient overall satisfaction with the pocket location at 24 months as measured using a visual analog scale (VAS 0-10. Secondary endpoints are: complications, patient-reported satisfaction at 1, 12, and 24 months (overall satisfaction, pain, discomfort, degree of unsightly appearance, movement problems, and sleep problems due to device.ConclusionsPOCKET is a prospective interventional RCT designed to evaluate if intramuscular is superior to subcutaneous placement of a bradycardia pacemaker during a two-year follow-up.

SU-E-T-585: Optically-Stimulated Luminescent Dosimeters for Monitoring Pacemaker Dose in Radiation Therapy

International Nuclear Information System (INIS)

Apicello, L; Riegel, A; Jamshidi, A

2015-01-01

Purpose: A sufficient amount of ionizing radiation can cause failure to components of pacemakers. Studies have shown that permanent damage can occur after a dose of 10 Gy and minor damage to functionality occurs at doses as low as 2 Gy. Optically stimulated thermoluminescent dosimeters (OSLDs) can be used as in vivo dosimeters to predict dose to be deposited throughout the treatment. The purpose of this work is to determine the effectiveness of using OSLDs for in vivo dosimetry of pacemaker dose. Methods: As part of a clinical in vivo dosimetry experience, OSLDs were placed at the site of the pacemaker by the therapist for one fraction of the radiation treatment. OSLD measurements were extrapolated to the total dose to be received by the pacemaker during treatment. A total of 79 measurements were collected from November 2011 to December 2013 on six linacs. Sixty-six (66) patients treated in various anatomical sites had the dose of their pacemakers monitored. Results: Of the 79 measurements recorded, 76 measurements (96 %) were below 2 Gy. The mean and standard deviation were 50.12 ± 76.41 cGy. Of the 3 measurements that exceeded 2 Gy, 2 measurements matched the dose predicted in the treatment plan and 1 was repeated after an unexpectedly high Result. The repeated measurement yielded a total dose less than 2 Gy. Conclusion: This analysis suggests OSLDs may be used for in vivo monitoring of pacemaker dose. Further research should be performed to assess the effect of increased backscatter from the pacemaker device

Placement Of Cardiac PacemaKEr Trial (POCKET – rationale and design: a randomized controlled trial

Directory of Open Access Journals (Sweden)

Peter Magnusson

2017-04-01

Full Text Available Background: A pacemaker system consists of one or two leads connected to a device that is implanted into a pocket formed just below the collarbone. This pocket is typically subcutaneous, that is, located just above the pectoral fascia. Even though the size of pacemakers has decreased markedly, complications due to superficial implants do occur. An alternative technique would be intramuscular placement of the pacemaker device, but there are no randomized controlled trials (RCTs to support this approach, which is the rationale for the Placement Of Cardiac PacemaKEr Trial (POCKET. The aim is to study if intramuscular is superior to subcutaneous placement of a pacemaker pocket. Methods: In October 2016, we started to enroll 200 consecutive patients with an indication for bradycardia pacemaker implantation. Patients are randomized to random block sizes, stratified by age group (cut-off: 65 years and sex, and then randomized to either subcutaneous or intramuscular implant. A concealed allocation procedure is employed, using sequentially numbered, sealed envelopes. Pocket site is blinded to the patient and in all subsequent care. The primary endpoint is patient overall satisfaction with the pocket location at 24 months as measured using a visual analog scale (VAS 0-10. Secondary endpoints are: complications, patient-reported satisfaction at 1, 12, and 24 months (overall satisfaction, pain, discomfort, degree of unsightly appearance, movement problems, and sleep problems due to device. Conclusions: POCKET is a prospective interventional RCT designed to evaluate if intramuscular is superior to subcutaneous placement of a bradycardia pacemaker during a two-year follow-up.

Case study thoracic radiotherapy in an elderly patient with pacemaker: The issue of pacing leads

Energy Technology Data Exchange (ETDEWEB)

Kirova, Youlia M., E-mail: youlia.kirova@curie.net [Department of Radiation Oncology, Institut Curie, Paris (France); Menard, Jean; Chargari, Cyrus; Mazal, Alejandro [Department of Radiation Oncology, Institut Curie, Paris (France); Kirov, Krassen [Department of Anesthesiology and Reanimation, Institut Curie, Paris (France)

2012-07-01

To assess clinical outcome of patients with pacemaker treated with thoracic radiation therapy for T8-T9 paravertebral chloroma. A 92-year-old male patient with chloroma presenting as paravertebral painful and compressive (T8-T9) mass was referred for radiotherapy in the Department of Radiation Oncology, Institut Curie. The patient presented with cardiac dysfunction and a permanent pacemaker that had been implanted prior. The decision of Multidisciplinary Meeting was to deliver 30 Gy in 10 fractions for reducing the symptoms and controlling the tumor growth. The patient received a total dose of 30 Gy in 10 fractions using 4-field conformal radiotherapy with 20-MV photons. The dose to pacemaker was 0.1 Gy but a part of the pacing leads was in the irradiation fields. The patient was treated the first time in the presence of his radiation oncologist and an intensive care unit doctor. Moreover, the function of his pacemaker was monitored during the entire radiotherapy course. No change in pacemaker function was observed during any of the radiotherapy fractions. The radiotherapy was very well tolerated without any side effects. The function of the pacemaker was checked before and after the radiotherapy treatment by the cardiologist and no pacemaker dysfunction was observed. Although updated guidelines are needed with acceptable dose criteria for implantable cardiac devices, it is possible to treat patients with these devices and parts encroaching on the radiation field. This case report shows we were able to safely treat our patient through a multidisciplinary approach, monitoring the patient during each step of the treatment.

SU-E-T-585: Optically-Stimulated Luminescent Dosimeters for Monitoring Pacemaker Dose in Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Apicello, L [Hofstra University, Hempstead, NY (United States); Riegel, A; Jamshidi, A [North Shore LIJ Health System, Lake Success, NY (United States)

2015-06-15

Purpose: A sufficient amount of ionizing radiation can cause failure to components of pacemakers. Studies have shown that permanent damage can occur after a dose of 10 Gy and minor damage to functionality occurs at doses as low as 2 Gy. Optically stimulated thermoluminescent dosimeters (OSLDs) can be used as in vivo dosimeters to predict dose to be deposited throughout the treatment. The purpose of this work is to determine the effectiveness of using OSLDs for in vivo dosimetry of pacemaker dose. Methods: As part of a clinical in vivo dosimetry experience, OSLDs were placed at the site of the pacemaker by the therapist for one fraction of the radiation treatment. OSLD measurements were extrapolated to the total dose to be received by the pacemaker during treatment. A total of 79 measurements were collected from November 2011 to December 2013 on six linacs. Sixty-six (66) patients treated in various anatomical sites had the dose of their pacemakers monitored. Results: Of the 79 measurements recorded, 76 measurements (96 %) were below 2 Gy. The mean and standard deviation were 50.12 ± 76.41 cGy. Of the 3 measurements that exceeded 2 Gy, 2 measurements matched the dose predicted in the treatment plan and 1 was repeated after an unexpectedly high Result. The repeated measurement yielded a total dose less than 2 Gy. Conclusion: This analysis suggests OSLDs may be used for in vivo monitoring of pacemaker dose. Further research should be performed to assess the effect of increased backscatter from the pacemaker device.

Safety of holmium laser prostatectomy in patients with cardiac pacemaker implant

Directory of Open Access Journals (Sweden)

Narmada P Gupta

2006-01-01

Full Text Available Objectives: The use of the standard monopolar electrocautery is associated with significant risks of implant malfunction in patients on a cardiac pacemaker. It is also associated with a risk of adverse cardiac events due to blood loss and fluid absorption. The properties of the holmium laser prevent the occurrence of these adverse events. We report the successful use of this technology in resecting the gland in patients on a permanent cardiac pacemaker implant. MATERIALS AND Methods: Six patients with permanent cardiac pacemaker implant were treated with holmium laser resection of prostate over a period of two years. Treated patients had bothersome prostatic symptoms and failed to respond to medical therapy. All patients were operated under spinal anesthesia using a high power VersaPulse ® PowerSuiteTM Holmium laser source. Normal saline was used as irrigant. Intravesical tissue morcellator was also used to remove the larger fragments in two of the patients. Results : Median patient age was 60 years (range 56-73 and median prostate volume was 40cc (range 20-48cc. None of the patient required blood transfusion or had significant hyponatremia or Transurethral resection syndrome. No patients had any pacemaker malfunction or hemodynamic instability during the procedure or in immediate postoperative period. Improvement in maximum urine flow rate was observed from an average of 7 ml/sec in preoperative period to 22 ml/sec postoperatively at 3 month followup. Conclusions: Holmium laser prostatectomy offers the ideal modality of surgery in patients on a cardiac pacemaker. It helps to avoid additional preparation and minimizes the risk of device malfunction and adverse post operative events.

Autaptic pacemaker mediated propagation of weak rhythmic activity across small-world neuronal networks

Science.gov (United States)

Yilmaz, Ergin; Baysal, Veli; Ozer, Mahmut; Perc, Matjaž

2016-02-01

We study the effects of an autapse, which is mathematically described as a self-feedback loop, on the propagation of weak, localized pacemaker activity across a Newman-Watts small-world network consisting of stochastic Hodgkin-Huxley neurons. We consider that only the pacemaker neuron, which is stimulated by a subthreshold periodic signal, has an electrical autapse that is characterized by a coupling strength and a delay time. We focus on the impact of the coupling strength, the network structure, the properties of the weak periodic stimulus, and the properties of the autapse on the transmission of localized pacemaker activity. Obtained results indicate the existence of optimal channel noise intensity for the propagation of the localized rhythm. Under optimal conditions, the autapse can significantly improve the propagation of pacemaker activity, but only for a specific range of the autaptic coupling strength. Moreover, the autaptic delay time has to be equal to the intrinsic oscillation period of the Hodgkin-Huxley neuron or its integer multiples. We analyze the inter-spike interval histogram and show that the autapse enhances or suppresses the propagation of the localized rhythm by increasing or decreasing the phase locking between the spiking of the pacemaker neuron and the weak periodic signal. In particular, when the autaptic delay time is equal to the intrinsic period of oscillations an optimal phase locking takes place, resulting in a dominant time scale of the spiking activity. We also investigate the effects of the network structure and the coupling strength on the propagation of pacemaker activity. We find that there exist an optimal coupling strength and an optimal network structure that together warrant an optimal propagation of the localized rhythm.

Risk of pacemaker implantation subsequent to radiotherapy for early-stage breast cancer in Denmark, 1982-2005

DEFF Research Database (Denmark)

Rehammar, Jens Christian; Videbaek, L.; Brock Johansen, J.

2015-01-01

. Objectives: The aim of this study was to examine the risk of severe conduction abnormalities evaluated by implantation of a pacemaker, subsequent to breast cancer radiotherapy. Methods: From the database of the Danish Breast Cancer Collaborative Group, we identified women treated with radiotherapy for early......-stage breast cancer in Denmark from 1982 to 2005. By record linkage to the Danish Pacemaker and ICD Registry information was retrieved on pacemaker implants subsequent to radiotherapy. Rate ratios (RR) of pacemaker implantation for left versus right sided breast cancer were calculated. Results: Among 18......,308 women treated with radiotherapy for early-stage breast cancer, 179 women had a pacemaker implanted subsequent to radiotherapy, 90 in 9,315 left sided and 89 in 8,993 right sided breast cancers. The unadjusted RR was 1.02 (0.76-1.36 95% CI, p=0.91) and the RR adjusted for year, age and time since...

Battery Malfunction of a Leadless Cardiac Pacemaker - A Worrisome Single-Center Experience.

Science.gov (United States)

Richter, Sergio; Döring, Michael; Ebert, Micaela; Bode, Kerstin; Müssigbrodt, Andreas; Sommer, Philipp; Husser, Daniela; Hindricks, Gerhard

2018-03-14

Leadless cardiac pacemaker (LCP) therapy has been established clinically as a feasible and safe alternative to conventional transvenous pacemaker therapy for patients with an indication for single-chamber right-ventricular pacing. 1-3 However, reports on loss of telemetry and pacing output due to abrupt battery failure called the safety of one of the two commercially available systems seriously into question. The initial battery advisory with the Nanostim™ LCP was issued by the manufacturer in October 2016, who instantly called a global stop to Nanostim™ implants. To this day, similar battery issues have not been described for the Micra™ transcatheter pacing system. Therefore, we thought to analyze the long-term pacemaker performance and rate of battery malfunction of the Nanostim™ LCP in our patient population.

Recent advances in understanding total-dose effects in bipolar transistors

International Nuclear Information System (INIS)

Schrimpf, R.D.

1996-01-01

Gain degradation in irradiated bipolar transistors can be a significant problem, particularly in linear integrated circuits. In many bipolar technologies, the degradation is greater for irradiation at low dose rates than it is for typical laboratory dose rates. Ionizing radiation causes the base current in bipolar transistors to increase, due to the presence of net positive charge in the oxides covering sensitive device areas and increases in surface recombination velocity. Understanding the mechanisms responsible for radiation-induced gain degradation in bipolar transistors is important in developing appropriate hardness assurance methods. This paper reviews recent modeling and experimental work, with the emphasis on low-dose-rate effects. A promising hardness assurance method based on irradiation at elevated temperatures is described

Pre-ejection period by radial artery tonometry supplements echo doppler findings during biventricular pacemaker optimization

Directory of Open Access Journals (Sweden)

Qamruddin Salima

2011-07-01

Full Text Available Abstract Background Biventricular (Biv pacemaker echo optimization has been shown to improve cardiac output however is not routinely used due to its complexity. We investigated the role of a simple method involving computerized pre-ejection time (PEP assessment by radial artery tonometry in guiding Biv pacemaker optimization. Methods Blinded echo and radial artery tonometry were performed simultaneously in 37 patients, age 69.1 ± 12.8 years, left ventricular (LV ejection fraction (EF 33 ± 10%, during Biv pacemaker optimization. Effect of optimization on echo derived velocity time integral (VTI, ejection time (ET, myocardial performance index (MPI, radial artery tonometry derived PEP and echo-radial artery tonometry derived PEP/VTI and PEP/ET indices was evaluated. Results Significant improvement post optimization was achieved in LV ET (286.9 ± 37.3 to 299 ± 34.6 ms, p Conclusion An acute shortening of PEP by radial artery tonometry occurs post Biv pacemaker optimization and correlates with improvement in hemodynamics by echo Doppler and may provide a cost-efficient approach to assist with Biv pacemaker echo optimization.

Pacemaker Use in New Zealand - Data From the New Zealand Implanted Cardiac Device Registry (ANZACS-QI 15).

Science.gov (United States)

Larsen, P D; Kerr, A J; Hood, M; Harding, S A; Hooks, D; Heaven, D; Lever, N A; Sinclair, S; Boddington, D; Tang, E W; Swampillai, J; Stiles, M K

2017-03-01

The New Zealand Cardiac Implanted Device Registry (Device) has recently been developed under the auspices of the New Zealand Branch of the Cardiac Society of Australia and New Zealand. This study describes the initial Device registry cohort of patients receiving a new pacemaker, their indications for pacing and their perioperative complications. The Device Registry was used to audit patients receiving a first pacemaker between 1 st January 2014 and 1 st June 2015. We examined 1611 patients undergoing first pacemaker implantation. Patients were predominantly male (59%), and had a median age of 70 years. The most common symptom for pacemaker implantation was syncope (39%), followed by dizziness (30%) and dyspnoea (12%). The most common aetiology for a pacemaker was a conduction tissue disorder (35%), followed by sinus node dysfunction (22%). Atrioventricular (AV) block was the most common ECG abnormality, present in 44%. Dual chamber pacemakers were most common (62%), followed by single chamber ventricular pacemakers (34%), and cardiac resynchronisation therapy - pacemakers (CRT-P) (2%). Complications within 24hours of the implant procedure were reported in 64 patients (3.9%), none of which were fatal. The most common complication was the need for reoperation to manipulate a lead, occurring in 23 patients (1.4%). This is the first description of data entered into the Device registry. Patients receiving a pacemaker were younger than in European registries, and there was a low use of CRT-P devices compared to international rates. Complications rates were low and compare favourably to available international data. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

International Society for Bipolar Disorders Task Force on Suicide

DEFF Research Database (Denmark)

Schaffer, Ayal; Isometsä, Erkki T; Tondo, Leonardo

2015-01-01

significantly associated with suicide attempts were: female gender, younger age at illness onset, depressive polarity of first illness episode, depressive polarity of current or most recent episode, comorbid anxiety disorder, any comorbid substance use disorder, alcohol use disorder, any illicit substance use......OBJECTIVES: Bipolar disorder is associated with a high risk of suicide attempts and suicide death. The main objective of the present study was to identify and quantify the demographic and clinical correlates of attempted and completed suicide in people with bipolar disorder. METHODS: Within...... the framework of the International Society for Bipolar Disorders Task Force on Suicide, a systematic review of articles published since 1980, characterized by the key terms bipolar disorder and 'suicide attempts' or 'suicide', was conducted, and data extracted for analysis from all eligible articles...

Modulation of Pacemaker Potentials by Pyungwi-San in Interstitial Cells of Cajal from Murine Small Intestine - Pyungwi-San and Interstitial Cells of Cajal -

Directory of Open Access Journals (Sweden)

Kim Jung Nam

2013-03-01

Full Text Available Objective: Pyungwi-san (PWS plays a role in a number of physiologic and pharmacologic functions in many organs. Interstitial cells of Cajal (ICCs are pacemaker cells that generate slow waves in the gastrointestinal (GI tract. We aimed to investigate the beneficial effects of PWS in mouse small-intestinal ICCs. Methods: Enzymatic digestion was used to dissociate ICCs from the small intestine of a mouse. The wholecell patch-clamp configuration was used to record membrane potentials from the cultured ICCs. Results: ICCs generated pacemaker potentials in the GI tract. PWS produced membrane depolarization in the current clamp mode. Pretreatment with a Ca2+-free solution and a thapsigargin, a Ca2+-ATPase, inhibitor in the endoplasmic reticulum, eliminated the generation of pacemaker potentials. However, only when the thapsigargin was applied in a bath solution, the membrane depolarization was not produced by PWS. Furthermore, the membrane depolarizations due to PWS were inhibited not by U-73122, an active phospholipase C inhibitor, but by chelerythrine and calphostin C, protein kinase C inhibitors. Conclusions: These results suggest that PWS might affect GI motility by modulating the pacemaker activity in the ICCs.

Bipolar disorder in adolescence.

Science.gov (United States)

DeFilippis, Melissa; Wagner, Karen Dineen

2013-08-01

Bipolar disorder is a serious psychiatric condition that may have onset in childhood. It is important for physicians to recognize the symptoms of bipolar disorder in children and adolescents in order to accurately diagnose this illness early in its course. Evidence regarding the efficacy of various treatments is necessary to guide the management of bipolar disorder in youth. For example, several medications commonly used for adults with bipolar disorder have not shown efficacy for children and adolescents with bipolar disorder. This article reviews the prevalence, diagnosis, course, and treatment of bipolar disorder in children and adolescents and provides physicians with information that will aid in diagnosis and treatment.

Regulation of basal and reserve cardiac pacemaker function by interactions of cAMP mediated PKA-dependent Ca2+ cycling with surface membrane channels

Science.gov (United States)

Vinogradova, Tatiana M.; Lakatta, Edward G.

2009-01-01

Decades of intensive research of primary cardiac pacemaker, the sinoatrial node, have established potential roles of specific membrane channels in the generation of the diastolic depolarization, the major mechanism allowing sinoatrial node cells generate spontaneous beating. During the last three decades, multiple studies made either in the isolated sinoatrial node or sinoatrial node cells have demonstrated a pivotal role of Ca2+ and, specifically Ca2+-release from sarcoplasmic reticulum, for spontaneous beating of cardiac pacemaker. Recently, spontaneous, rhythmic local subsarcolemmal Ca2+ releases from ryanodine receptors during late half of the diastolic depolarization have been implicated as a vital factor in the generation of sinoatrial node cells spontaneous firing. Local Ca2+ releases are driven by a unique combination of high basal cAMP production by adenylyl cyclases, high basal cAMP degradation by phosphodiesterases and a high level of cAMP-mediated PKA-dependent phosphorylation. These local Ca2+ releases activate an inward Na+-Ca2+ exchange current which accelerates the terminal diastolic depolarization rate and, thus, controls the spontaneous pacemaker firing. Both the basal primary pacemaker beating rate and its modulation via β-adrenergic receptor stimulation appear to be critically dependent upon intact RyR function and local subsarcolemmal sarcoplasmic reticulum generated Ca2+ releases. This review aspires to integrate the traditional viewpoint that has emphasized the supremacy of the ensemble of surface membrane ion channels in spontaneous firing of the primary cardiac pacemaker, and these novel perspectives of cAMP-mediated PKA-dependent Ca2+ cycling in regulation of the heart pacemaker clock, both in the basal state and during β-adrenergic receptor stimulation. PMID:19573534

The influence of ionizing radiation on the probability of failure of long-term pacemakers

International Nuclear Information System (INIS)

Eger, H.; Hesse, W.; Otte, K.B.; Rauh, G.; Salewski, D.; Stopp, G.

1982-01-01

The functional disturbances observed during the exposure of cardiac pacemakers with a CMOS switching circle U 115 are described qualitatively for different types of radiation. Based on the maximum sensitivity of the U 115 within the X-ray range, the correlation for this range between dose of exposure and parameter changes is established. As is demonstrated such changes is established. As is demonstrated such changes are not clinically relevant as long as the dose of 5,16 x 10 -2 C/kg is not exceeded. Proceeding from the accumulated dose to which the U 115 is exposed during various diagnostic radiographic procedures it is shown that such procedures do not result in functional disturbances of the pacemaker. Recommendations are given for radiotherapeutic measures as to pacemaker patients, which should be realized in close co-operation between the pacemaker centre concerned and an authorized hospital. (author)

Permanent pacemaker implantation in octogenarians with unexplained syncope and positive electrophysiologic testing.

Science.gov (United States)

Giannopoulos, Georgios; Kossyvakis, Charalampos; Panagopoulou, Vasiliki; Tsiachris, Dimitrios; Doudoumis, Konstantinos; Mavri, Maria; Vrachatis, Dimitrios; Letsas, Konstantinos; Efremidis, Michael; Katsivas, Apostolos; Lekakis, John; Deftereos, Spyridon

2017-05-01

Syncope is a common problem in the elderly, and a permanent pacemaker is a therapeutic option when a bradycardic etiology is revealed. However, the benefit of pacing when no association of symptoms to bradycardia has been shown is not clear, especially in the elderly. The aim of this study was to evaluate the effect of pacing on syncope-free mortality in patients aged 80 years or older with unexplained syncope and "positive" invasive electrophysiologic testing (EPT). This was an observational study. A positive EPT for the purposes of this study was defined by at least 1 of the following: a corrected sinus node recovery time of >525 ms, a basic HV interval of >55 ms, detection of infra-Hisian block, or appearance of second-degree atrioventricular block on atrial decremental pacing at a paced cycle length of >400 ms. Among the 2435 screened patients, 228 eligible patients were identified, 145 of whom were implanted with a pacemaker. Kaplan-Meier analysis determined that time to event (syncope or death) was 50.1 months (95% confidence interval 45.4-54.8 months) with a pacemaker vs 37.8 months (95% confidence interval 31.3-44.4 months) without a pacemaker (log-rank test, P = .001). The 4-year time-dependent estimate of the rate of syncope was 12% vs 44% (P pacemaker implantation was independently associated with longer syncope-free survival. Significant differences were also shown in the individual components of the primary outcome measure (syncope and death from any cause). Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

A Parametric Computational Model of the Action Potential of Pacemaker Cells.

Science.gov (United States)

Ai, Weiwei; Patel, Nitish D; Roop, Partha S; Malik, Avinash; Andalam, Sidharta; Yip, Eugene; Allen, Nathan; Trew, Mark L

2018-01-01

A flexible, efficient, and verifiable pacemaker cell model is essential to the design of real-time virtual hearts that can be used for closed-loop validation of cardiac devices. A new parametric model of pacemaker action potential is developed to address this need. The action potential phases are modeled using hybrid automaton with one piecewise-linear continuous variable. The model can capture rate-dependent dynamics, such as action potential duration restitution, conduction velocity restitution, and overdrive suppression by incorporating nonlinear update functions. Simulated dynamics of the model compared well with previous models and clinical data. The results show that the parametric model can reproduce the electrophysiological dynamics of a variety of pacemaker cells, such as sinoatrial node, atrioventricular node, and the His-Purkinje system, under varying cardiac conditions. This is an important contribution toward closed-loop validation of cardiac devices using real-time heart models.

Biventricular pacemaker implantation with the BV Pulsera

Energy Technology Data Exchange (ETDEWEB)

Wright, J.D.W.; Todd, D.; Waktare, J.E.P.; Hughes, S.; Abell, C. [The Cardiothoracic Centre, Liverpool (United Kingdom)

2005-07-01

The BV Pulsera mobile X-ray system is used for biventricular pacemaker implantation in a surgical environment. It provides high-quality images of the moving structures, including the fine coronary leads, and can be used for long fluoroscopy runs without overheating. (orig.)

Biventricular pacemaker implantation with the BV Pulsera

International Nuclear Information System (INIS)

Wright, J.D.W.; Todd, D.; Waktare, J.E.P.; Hughes, S.; Abell, C.

2005-01-01

The BV Pulsera mobile X-ray system is used for biventricular pacemaker implantation in a surgical environment. It provides high-quality images of the moving structures, including the fine coronary leads, and can be used for long fluoroscopy runs without overheating. (orig.)

Intra-cardiac pacemaker infection: Surgical management and outcome

Directory of Open Access Journals (Sweden)

Sameh Elameen

2016-05-01

Conclusion: Explantation of the complete pacemaker system has proved a reliable method to eradicate infection. Complications were rare, except in patients who present lately in a critically ill condition and septic shock.

Anxiety, stress and perfectionism in bipolar disorder.

Science.gov (United States)

Corry, Justine; Green, Melissa; Roberts, Gloria; Frankland, Andrew; Wright, Adam; Lau, Phoebe; Loo, Colleen; Breakspear, Michael; Mitchell, Philip B

2013-12-01

Previous reports have highlighted perfectionism and related cognitive styles as a psychological risk factor for stress and anxiety symptoms as well as for the development of bipolar disorder symptoms. The anxiety disorders are highly comorbid with bipolar disorder but the mechanisms that underpin this comorbidity are yet to be determined. Measures of depressive, (hypo)manic, anxiety and stress symptoms and perfectionistic cognitive style were completed by a sample of 142 patients with bipolar disorder. Mediation models were used to explore the hypotheses that anxiety and stress symptoms would mediate relationships between perfectionistic cognitive styles, and bipolar disorder symptoms. Stress and anxiety both significantly mediated the relationship between both self-critical perfectionism and goal attainment values and bipolar depressive symptoms. Goal attainment values were not significantly related to hypomanic symptoms. Stress and anxiety symptoms did not significantly mediate the relationship between self-critical perfectionism and (hypo)manic symptoms. 1. These data are cross-sectional; hence the causality implied in the mediation models can only be inferred. 2. The clinic patients were less likely to present with (hypo)manic symptoms and therefore the reduced variability in the data may have contributed to the null findings for the mediation models with (hypo) manic symptoms. 3. Those patients who were experiencing current (hypo)manic symptoms may have answered the cognitive styles questionnaires differently than when euthymic. These findings highlight a plausible mechanism to understand the relationship between bipolar disorder and the anxiety disorders. Targeting self-critical perfectionism in the psychological treatment of bipolar disorder when there is anxiety comorbidity may result in more parsimonious treatments. © 2013 Published by Elsevier B.V.

Case Report of Radiotherapy to a Breast Cancer Patient with a Pacemaker

Energy Technology Data Exchange (ETDEWEB)

Chae, Seung Hoon; Park, Jang Pil; Lee, Yang Hoon; Yoo, Suk Hyun [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of); Seong, Won Mo [Interdisciplinary Program of Radiation Applied Life Science, Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Kyu Bo [Dept. of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of)

2012-09-15

In this study, we considerate our radiation therapy process for the breast cancer patient implanted a pacemaker applying the machine movement surgery, shielding, beam selection. We perform radiation therapy to a 54 years old, breast cancer patient implanted a pacemaker. The patient underwent a surgery to move the position of a pacemaker to right side breast after consultation with cardiology department. Prescribed dose was 5,040 cGy and daily dose 180 cGy for 28 fractions. The 10 MV photon energy, field size 0/9.5x20 cm, half beam and opposing portal irradiation are used. To find out appropriate thickness of shielding board, we carried out an experiment using a solid water phantom (30x30x7 cm), a Farmer-type chamber (TN30013, PTW, Germany) and a shielding board (Pb 28x27x0.1 cm). We calculated expected absorbed dose to te pacemaker with absorb ratio and shielding ratio. In the PTP system (Eclipse, Varian, USA), we figured out how much radiation would be absorbed to the machine with and without shielding. First day of the radiation therapy, we measured head scatter to the pacemaker with MOSFET Dose Verification System (TN-RD-70-W, Medical Canada Ltd., Canada). In the phantom measurement, we found out appropriate thickness was 2 mm of shielding board. In the RTP, when using 2 mm shielding the pacemaker will be absorbed 11.5-38.2 cGy and DVH is 77.3 cGy. In the first day of the therapy, 4.3 cGy was measured so 120.4 cGy was calculated during total therapy. The patient was free from any side effects, and the machine also normally functioned. As the report of association which have public confidence became superannuated, there is lack of data about new machine. We believe that radiation therapy to these kind of patients could be done successfully with co-operation, patient-suitable planning, accurate QA, frequent in-vivo dosimetry and monitoring.

[BIPOLAR DISORDER AS A MULTI-SYSTEM ILLNESS].

Science.gov (United States)

Fenchel, Daphna; Levkovitz, Yechiel; Kotler, Moshe

2017-12-01

Bipolar disorder is a chronic condition, characterized by high distress in patients and high suicide rates (30%). Most patients suffer from medical and other psychiatric comorbidities, which worsen the psychiatric symptoms and decrease the likelihood of remission. More than 70% of bipolar patients have cardio-metabolic symptoms, with higher rates compared to other psychiatric disorders. Cardiovascular disease is the major cause of high mortality rates in these patients, with 1.5-2 fold increased risk of mortality, compared to the general population without psychiatric symptoms. The rates of cardiovascular risk factors and their resulting increased mortality rates are similar to those found in schizophrenia. In addition to cardio-metabolic conditions, 50% of patients with bipolar disorder suffer from other medical symptoms, which are also associated with worse outcomes. Therefore, the current perspective is that bipolar disorder is not only a psychiatric disorder, but rather a multi-system illness, affecting the entire body. The optimal treatment for these patients should include diagnosis, monitoring and treatment of both psychiatric and physical symptoms, which would improve their prognosis.

Validity and reliability of the Cognitive Complaints in Bipolar Disorder Rating Assessment (COBRA) in Japanese patients with bipolar disorder.

Science.gov (United States)

Toyoshima, Kuniyoshi; Fujii, Yutaka; Mitsui, Nobuyuki; Kako, Yuki; Asakura, Satoshi; Martinez-Aran, Anabel; Vieta, Eduard; Kusumi, Ichiro

2017-08-01

In Japan, there are currently no reliable rating scales for the evaluation of subjective cognitive impairment in patients with bipolar disorder. We studied the relationship between the Japanese version of the Cognitive Complaints in Bipolar Disorder Rating Assessment (COBRA) and objective cognitive assessments in patients with bipolar disorder. We further assessed the reliability and validity of the COBRA. Forty-one patients, aged 16-64, in a remission period of bipolar disorder were recruited from Hokkaido University Hospital in Sapporo, Japan. The COBRA (Japanese version) and Frankfurt Complaint Questionnaire (FCQ), the gold standard in subjective cognitive assessment, were administered. A battery of neuropsychological tests was employed to measure objective cognitive impairment. Correlations among the COBRA, FCQ, and neuropsychological tests were determined using Spearman's correlation coefficient. The Japanese version of the COBRA had high internal consistency, good retest reliability, and concurrent validity-as indicated by a strong correlation with the FCQ. A significant correlation was also observed between the COBRA and objective cognitive measurements of processing speed. These findings are the first to demonstrate that the Japanese version of the COBRA may be clinically useful as a subjective cognitive impairment rating scale in Japanese patients with bipolar disorder. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

W/kit gene required for interstitial cells of Cajal and for intestinal pacemaker activity

DEFF Research Database (Denmark)

Huizinga, J D; Thuneberg, L; Klüppel, M

1995-01-01

The pacemaker activity in the mammalian gut is responsible for generating anally propagating phasic contractions. The cellular basis for this intrinsic activity is unknown. The smooth muscle cells of the external muscle layers and the innervated cellular network of interstitial cells of Cajal......, which is closely associated with the external muscle layers of the mammalian gut, have both been proposed to stimulate pacemaker activity. The interstitial cells of Cajal were identified in the last century but their developmental origin and function have remained unclear. Here we show...... of Cajal associated with Auerbach's nerve plexus and intestinal pacemaker activity....

Are working memory deficits in bipolar disorder markers for psychosis?

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Allen, Daniel N; Randall, Carol; Bello, Danielle; Armstrong, Christina; Frantom, Linda; Cross, Chad; Kinney, Jefferson

2010-03-01

Working memory deficits have been identified in bipolar disorder, but there is evidence suggesting that these deficits may be markers for psychosis rather than affective disorder. The current study examined this issue by comparing two groups of individuals with bipolar disorder, one with psychotic features and one without psychotic features, with a group of normal controls. Working memory was conceptualized as a multicomponent system that includes auditory and visuospatial short-term stores, executive control processes, and an episodic buffer that allows for communication between short- and long-term memory stores (Baddeley & Logie, 1999). Results indicated that only executive control processes significantly differentiated the psychotic and nonpsychotic bipolar groups, although visuospatial working memory differentiated both bipolar groups from controls. The results support the idea that some aspects of working memory performance are markers for psychosis, while others may be more general markers for bipolar disorders. Copyright 2010 APA, all rights reserved

Cardiac pacemaker

International Nuclear Information System (INIS)

Kolenik, S.A.

1976-01-01

The construction of a cardiac pacemaker is described which is characterized by particularly small dimensions, small weight and long life duration. The weight is under 100g, the specific weight under 1.7. Mass inertia forces which occur through acceleration and retardation processes, thus remain below the threshold values, above which one would have to reckon with considerable damaging of the surrounding body tissue. The maintaining of small size and slight weight is achieved by using an oscillator on COSMOS basis, where by considerably lower energy consumption, amongst others the lifetimes of the batteries used - a lithium anode with thionyl chloride electrolyte - is extended to over 5 years. The reliability can be increased by the use of 2 or more batteries. The designed dimension are 20x60x60 mm 3 . (ORU/LH) [de

Do current national and international guidelines have specific recommendations for older adults with bipolar disorder? A brief report.

Science.gov (United States)

Dols, Annemiek; Kessing, Lars Vedel; Strejilevich, Sergio A; Rej, Soham; Tsai, Shang-Ying; Gildengers, Ariel G; Almeida, Osvaldo P; Shulman, Kenneth I; Sajatovic, Martha

2016-12-01

Older adults with bipolar disorder (OABD) are a growing segment of patients with bipolar disorder (BD) for which specific guidelines are warranted. Although, OABD are frequently excluded from randomized controlled trials due to their age or somatic comorbidity, more treatment data from a variety of sources have become available in recent years. It is expected that at least some of this emerging information on OABD would be incorporated into treatment guidelines available to clinicians around the world. The International Society of Bipolar Disorders OABD task force compiled and compared recommendations from current national and international guidelines that specifically address geriatric or older individuals with BD (from year 2005 onwards). There were 34 guidelines, representing six continents and 19 countries. The majority of guidelines had no separate section on OABD. General principles for treating OABD with medication are recommended to be similar to those for younger adults, with special caution for side effects due to somatic comorbidity and concomitant medications. Therapeutic lithium serum levels are suggested to be lower but recommendations are very general and mostly not informed by specific research evidence. There is a lack of emphasis of OABD-specific issues in existing guidelines. Given the substantial clinical heterogeneity in BD across the life span, along with the rapidly expanding population of older individuals worldwide, and limited mental health workforce with geriatric expertise, it is critical that additional effort and resources be devoted to studying treatment interventions specific to OABD and that treatment guidelines reflect research findings. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

PHARMAC and treatment of bipolar depression--the limits of utilitarianism.

Science.gov (United States)

Ellis, Pete; Mulder, Roger; Porter, Richard

2006-03-31

Bipolar disorder affects 1.6% of the population. The majority of the burden of illness for people with bipolar disorder is due to depression. Suicide rates for people with bipolar disorder are 15 times higher than in the general population, and the majority of these deaths occur during depressive episodes. More effective prevention of such depressive episodes is important. Lamotrigine is an anticonvulsant and a mood stabiliser that is more effective at preventing depressive relapses than most other mood stabilising drugs. Its use for this purpose has been recommended by English language treatment guidelines since 2002. Lamotrigine is approved for use in the prophylaxis of depression in bipolar disorder and for epilepsy. PHARMAC subsidises its use in treatment-resistant epilepsy (subject to a 'special authority' application) but not in bipolar disorder. The New Zealand Mental Health Strategy and the imminent New Zealand Suicide Strategy identify reducing suicide as a key goal. Among other initiatives, this requires effective treatment of bipolar depression, yet a treatment likely to support this is not currently subsidised.

Exfoliated MoS₂ nanosheets loaded on bipolar exchange membranes interfaces as advanced catalysts for water dissociation

DEFF Research Database (Denmark)

Li, Jian; Morthensen, Sofie Thage; Zhu, Junyong

2018-01-01

. Bipolar membranes are key factors for splitting water at the interface of a cation and anion exchange layer in an electric field. The ideal bipolar membrane should have a low energy consumption, a high current efficiency and long-term stability. In order to investigate the catalytic effect of a monolayer...... this prediction. Furthermore, a bipolar membrane prepared at 90°C had a low swelling ratio of about 7.5% while maintaining a high water uptake of 71.6%. From the calculation of current efficiency and energy consumption, the bipolar membrane with a monolayer of MoS2 has a higher current efficiency (45......%) and a lower energy consumption (3.6 kW/h·kg) compared to a current efficiency of 24% and an energy consumption of 6.3 kW/h·kg for a bipolar membrane without MoS2. This study proves the catalytic function of MoS2, which lays a foundation for further research on catalytic bipolar exchange membranes....

Bipolar Disorder

Science.gov (United States)

Bipolar disorder is a serious mental illness. People who have it go through unusual mood changes. They go ... The down feeling is depression. The causes of bipolar disorder aren't always clear. It runs in families. ...

Quality assessment of pacemaker implantations in Denmark

DEFF Research Database (Denmark)

Møller, M; Arnsbo, P; Asklund, Mogens

2002-01-01

AIMS: Quality assessment of therapeutic procedures is essential to insure a cost-effective health care system. Pacemaker implantation is a common procedure with more than 500,000 implantations world-wide per year, but the general complication rate is not well described. We studied procedure relat...

Interference of apex locator, pulp tester and diathermy on pacemaker function

OpenAIRE

Narayanan Sriman; V Prabhakar; J S Bhuvaneswaran; N Subha

2015-01-01

Aim: The purpose of this study was to evaluate the effects of three electronic apex locators (EAL), electric pulp tester (EPT) and diathermy on pacemaker function in vitro. Materials and Methods: Three EALs: Root ZX (J. Morita Co., Tustin, CA, U.S.A.), Propex (Dentsply), Mini Apex locator (SybronEndo, Anaheim, CA, USA), EPT (Parkell pulp vitality tester Farmingdale, NY, USA) and Diathermy (Neomed 250 B) were tested for any interference with one pacemaker (A medtronic kappa KVDD901-serial ...

Exploring the mechanism of action of the sperm-triggered calcium-wave pacemaker in ascidian zygotes.

Science.gov (United States)

Carroll, Michael; Levasseur, Mark; Wood, Chris; Whitaker, Michael; Jones, Keith T; McDougall, Alex

2003-12-15

In ascidians, as in mammals, sperm trigger repetitive Ca2+-waves that originate from cortical pacemakers situated in the vegetal hemisphere of the zygotes. In ascidians, a vegetal protrusion termed the contraction pole (CP) acts as the Ca2+-wave pacemaker, but the mechanism that underlies the generation of a Ca2+-wave pacemaker is not known. Here, we tested four hypotheses to determine which factors at the CP are involved in setting the pace of the ascidian Ca2+-wave pacemaker: (1) localized Ca2+ influx; (2) accumulation of phosphatidylinositol (4,5)bisphosphate [PtdIns(4,5)P2]; (3) accumulation of cortical endoplasmic reticulum (cER); and (4) enrichment of the sperm activating factor. We developed a method of dynamically monitoring the location of the CP during fertilization using a plekstrin homology (PH) domain from phospholipase Cdelta1 coupled to green fluorescent protein (GFP) that binds PtdIns(4,5)P2. We found that eggs in Ca2+-free sea water displayed Ca2+ waves that originated from the CP, showing that enhanced CP Ca2+ influx does not determine the origin of the pacemaker. Also, disruption of the PH::GFP-labelled CP once it had formed did not dislodge the Ca2+-wave pacemaker from that site. Next, when we prevented the accumulation of cER at the CP, all of the Ca2+ waves came from the site of sperm-egg fusion and the frequency of Ca2+ oscillations was unaltered. These data show that local Ca2+ influx, the accumulation of PtdIns(4,5)P2 and cER at the CP are not required for Ca2+-wave pacemaker function and instead suggest that a factor associated with the sperm determines the site of the Ca2+-wave pacemaker. Finally, when we injected ascidian sperm extract into the centre of unfertilized ascidian eggs that had been treated with microfilament- and microtubule-disrupting drugs, all the Ca2+ waves still originated from near the plasma membrane, showing that the sperm factor does not require an intact cortex if it is enriched near the plasma membrane (PM). We

Identification and functional characterization of cardiac pacemaker cells in zebrafish.

Directory of Open Access Journals (Sweden)

Federico Tessadori

Full Text Available In the mammalian heart a conduction system of nodes and conducting cells generates and transduces the electrical signals evoking myocardial contractions. Specialized pacemaker cells initiating and controlling cardiac contraction rhythmicity are localized in an anatomically identifiable structure of myocardial origin, the sinus node. We previously showed that in mammalian embryos sinus node cells originate from cardiac progenitors expressing the transcription factors T-box transcription factor 3 (Tbx3 and Islet-1 (Isl1. Although cardiac development and function are strikingly conserved amongst animal classes, in lower vertebrates neither structural nor molecular distinguishable components of a conduction system have been identified, questioning its evolutionary origin. Here we show that zebrafish embryos lacking the LIM/homeodomain-containing transcription factor Isl1 display heart rate defects related to pacemaker dysfunction. Moreover, 3D reconstructions of gene expression patterns in the embryonic and adult zebrafish heart led us to uncover a previously unidentified, Isl1-positive and Tbx2b-positive region in the myocardium at the junction of the sinus venosus and atrium. Through their long interconnecting cellular protrusions the identified Isl1-positive cells form a ring-shaped structure. In vivo labeling of the Isl1-positive cells by transgenic technology allowed their isolation and electrophysiological characterization, revealing their unique pacemaker activity. In conclusion we demonstrate that Isl1-expressing cells, organized as a ring-shaped structure around the venous pole, hold the pacemaker function in the adult zebrafish heart. We have thereby identified an evolutionary conserved, structural and molecular distinguishable component of the cardiac conduction system in a lower vertebrate.

Aberrant cerebellar connectivity in bipolar disorder with psychosis.

Science.gov (United States)

Shinn, Ann K; Roh, Youkyung S; Ravichandran, Caitlin T; Baker, Justin T; Öngür, Dost; Cohen, Bruce M

2017-07-01

The cerebellum, which modulates affect and cognition in addition to motor functions, may contribute substantially to the pathophysiology of mood and psychotic disorders, such as bipolar disorder. A growing literature points to cerebellar abnormalities in bipolar disorder. However, no studies have investigated the topographic representations of resting state cerebellar networks in bipolar disorder, specifically their functional connectivity to cerebral cortical networks. Using a well-defined cerebral cortical parcellation scheme as functional connectivity seeds, we compared ten cerebellar resting state networks in 49 patients with bipolar disorder and a lifetime history of psychotic features and 55 healthy control participants matched for age, sex, and image signal-to-noise ratio. Patients with psychotic bipolar disorder showed reduced cerebro-cerebellar functional connectivity in somatomotor A, ventral attention, salience, and frontoparietal control A and B networks relative to healthy control participants. These findings were not significantly correlated with current symptoms. Patients with psychotic bipolar disorder showed evidence of cerebro-cerebellar dysconnectivity in selective networks. These disease-related changes were substantial and not explained by medication exposure or substance use. Therefore, they may be mechanistically relevant to the underlying susceptibility to mood dysregulation and psychosis. Cerebellar mechanisms deserve further exploration in psychiatric conditions, and this study's findings may have value in guiding future studies on pathophysiology and treatment of mood and psychotic disorders, in particular.

Twenty-Seven Years Experience With Transvenous Pacemaker Implantation in Children Weighing <10 kg.

Science.gov (United States)

Konta, Laura; Chubb, Mark Henry; Bostock, Julian; Rogers, Jan; Rosenthal, Eric

2016-02-01

Epicardial pacemaker implantation is the favored approach in children weighing pacemaker implantation in neonates and infants from 1987. To date there have been no long-term follow-up reports of what is for many a controversial strategy. Between 1987 and 2003, 37 neonates and infants-median age 6.7 months (1 day to 3 years) and median weight 4.6 kg (2.7-10 kg)-had a permanent transvenous pacing system implanted. Pacing leads were placed into the right ventricular apex/outflow tract through a subclavian vein puncture with a redundant loop in the atrium. Three patients were lost to follow-up, 4 patients died from complications of cardiac surgery, and 2 patients had their system removed. At long-term follow-up in 28 patients at a median of 17.2 (range, 11.2-27.4) years, 10 patients have a single chamber ventricular pacemaker, 14 a dual chamber pacemaker, 3 a biventricular pacemaker, and 1 has a single chamber implantable cardioverter defibrillator. Subclavian vein patency was assessed in 26 patients. The overall subclavian vein occlusion rate was 10 of 13 (77%) 5 kg during long-term follow-up. After a median of 14.3 (range, 13.4-17.6) years of pacing, 7 patients continue with their original lead. Transvenous pacing in infants <10 kg results in encouraging short- and long-term clinical outcomes. Subclavian vein occlusion remains an important complication, occurring predominantly in those weighing <5 kg. © 2016 American Heart Association, Inc.

Correlation analysis of the relationship between B-type natriuretic peptide and selected echocardiographic parameters in patients with permanent pacemakers

Directory of Open Access Journals (Sweden)

Janusz Sielski

2016-01-01

Full Text Available Introduction: The present study was undertaken to evaluate the practical value of BNP measurements and echocardiographic left ventricular volume index in patients with permanent pacemakers because there are no such reports in the literature. Aim of the research: The aim of the study was to reveal multiple correlations between BNP levels and selected echocardiographic parameters of the left atrium in patients with permanent pacemakers. In the literature there are reports on the significance of BNP values and left atrial size in patients with permanent pacemakers. The results of the present study appear to be of value in the outpatient assessment of these patients. Material and methods: We analysed a group of 117 patients with permanent pacemakers (AAI/R 21 patients, DDD/R 59 patients, VVI/R 37 patients and 48 healthy volunteers serving as the control group. BNP measurements were performed on venous blood samples using Triage meters. The Simpson method and the ellipse method were used to assess the left atrium on echocardiography. Results: There was a significant correlation between BNP and maximum left atrial volume, minimum left atrial volume, and left atrial volume index in patients with AAI/R, DDD/R, and VVI/R pacemakers at 3 and 6 months after the implantation. Conclusions : In patients after implantation of permanent pacemakers there are correlations between BNP values and echocardiographic left atrial parameters, especially in patients with DDD/R pacemakers. Left atrial function improves in patients with DDD/R pacemakers. Pacemaker check-up should be extended to include BNP measurements and echocardiographic assessment of the left atrium.

Cognitive functions in the euthymic patients with bipolar disorder

International Nuclear Information System (INIS)

Ozdel, O.; Karadag, F.; Atesci, Figen C.; Oguzhanoglu, N.K.; Cabuk, T.

2007-01-01

Recent studies have focused on the nature of dysfunction in bipolar patients. The purpose of the current study was to investigate cognitive performance of individuals with bipolar disorder compared to healthy control subjects during a well-established euthymic period. The sample consisted of 27 bipolar euthymic patients and 21 control subjects. Verbal and visual memory performance, attention, executive functions and psychological functions were evaluated for each participant. Bipolar patients showed significant attentional deficit and executive dysfunction and also poor performance on verbal and visual memory tasks compared to the controls. Illness duration and lifetime total episode number and previous episode with psychotic features was associated with worsened performance on attention, executive and memory tasks. Psychological functioning was not associated with cognitive deficit. The present study showed persistent cognitive impairment on inhibitory control and selective attention as well as poor performance on verbal and visual memory tests in a group of bipolar euthymic patients. The impaired neuropsychological performance was associated with psychotic features. Attentional dysfunction seemed to be a trait abnormality for the sample studied. (author)

Novel multiple criteria decision making methods based on bipolar neutrosophic sets and bipolar neutrosophic graphs

OpenAIRE

Muhammad, Akram; Musavarah, Sarwar

2016-01-01

In this research study, we introduce the concept of bipolar neutrosophic graphs. We present the dominating and independent sets of bipolar neutrosophic graphs. We describe novel multiple criteria decision making methods based on bipolar neutrosophic sets and bipolar neutrosophic graphs. We also develop an algorithm for computing domination in bipolar neutrosophic graphs.

Percutaneously injectable fetal pacemaker: electrodes, mechanical design and implantation.

Science.gov (United States)

Zhou, Li; Chmait, Ramen; Bar-Cohen, Yaniv; Peck, Raymond A; Loeb, Gerald E

2012-01-01

We are developing a self-contained cardiac pacemaker with a small, cylindrical shape (~3 × 20 mm) that permits it to be implanted percutaneously into a fetus to treat complete heart block and consequent hydrops fetalis, which is otherwise fatal. The device uses off-the-shelf components including a rechargeable lithium cell and a highly efficient relaxation oscillator encapsulated in epoxy and glass. A corkscrew electrode made from activated iridium can be screwed into the myocardium, followed by release of the pacemaker and a short, flexible lead entirely within the chest of the fetus to avoid dislodgement from fetal movement. The feasibility of implanting the device percutaneously under ultrasonic imaging guidance was demonstrated in acute adult rabbit experiments.

Use of an active fixation lead and a subpectoral pacemaker pocket may not avoid Twiddler′s syndrome

Directory of Open Access Journals (Sweden)

Floris E A Udink ten Cate

2012-01-01

Full Text Available Manipulation of a pacemaker with consequent malfunction of the device has been called Twiddler′s syndrome. Use of active-fixation leads and subpectoral pacemaker pockets has been considered to help in avoiding this problem. We describe a child in whom twiddling was not prevented despite implantation of a lumenless atrial lead and insertion of the pacemaker generator in a subpectoral pocket.

Keeping the Rhythm : Cardiac Pacemaker Cell Development

NARCIS (Netherlands)

Burkhard, S.B.

2017-01-01

The heart is the first organ to form and function in the developing vertebrate embryo. Its proper morphogenesis and function is crucial for survival. Here we focus on the development and characterization of a highly specialized subset of cardiac cells, the pacemaker cells. In the mammalian heart,

Pituitary gland volumes in bipolar disorder.

Science.gov (United States)

Clark, Ian A; Mackay, Clare E; Goodwin, Guy M

2014-12-01

Bipolar disorder has been associated with increased Hypothalamic-Pituitary-Adrenal axis function. The mechanism is not well understood, but there may be associated increases in pituitary gland volume (PGV) and these small increases may be functionally significant. However, research investigating PGV in bipolar disorder reports mixed results. The aim of the current study was twofold. First, to assess PGV in two novel samples of patients with bipolar disorder and matched healthy controls. Second, to perform a meta-analysis comparing PGV across a larger sample of patients and matched controls. Sample 1 consisted of 23 established patients and 32 matched controls. Sample 2 consisted of 39 medication-naïve patients and 42 matched controls. PGV was measured on structural MRI scans. Seven further studies were identified comparing PGV between patients and matched controls (total n; 244 patients, 308 controls). Both novel samples showed a small (approximately 20mm(3) or 4%), but non-significant, increase in PGV in patients. Combining the two novel samples showed a significant association of age and PGV. Meta-analysis showed a trend towards a larger pituitary gland in patients (effect size: .23, CI: -.14, .59). While results suggest a possible small difference in pituitary gland volume between patients and matched controls, larger mega-analyses with sample sizes greater even than those used in the current meta-analysis are still required. There is a small but potentially functionally significant increase in PGV in patients with bipolar disorder compared to controls. Results demonstrate the difficulty of finding potentially important but small effects in functional brain disorders. Copyright © 2014 Elsevier B.V. All rights reserved.

Neutron absorbed dose in a pacemaker CMOS

International Nuclear Information System (INIS)

Borja H, C. G.; Guzman G, K. A.; Valero L, C.; Banuelos F, A.; Hernandez D, V. M.; Vega C, H. R.; Paredes G, L.

2012-01-01

The neutron spectrum and the absorbed dose in a Complementary Metal Oxide Semiconductor (CMOS), has been estimated using Monte Carlo methods. Eventually a person with a pacemaker becomes an oncology patient that must be treated in a linear accelerator. Pacemaker has integrated circuits as CMOS that are sensitive to intense and pulsed radiation fields. Above 7 MV therapeutic beam is contaminated with photoneutrons that could damage the CMOS. Here, the neutron spectrum and the absorbed dose in a CMOS cell was calculated, also the spectra were calculated in two point-like detectors in the room. Neutron spectrum in the CMOS cell shows a small peak between 0.1 to 1 MeV and a larger peak in the thermal region, joined by epithermal neutrons, same features were observed in the point-like detectors. The absorbed dose in the CMOS was 1.522 x 10 -17 Gy per neutron emitted by the source. (Author)

Neutron absorbed dose in a pacemaker CMOS

Energy Technology Data Exchange (ETDEWEB)

Borja H, C. G.; Guzman G, K. A.; Valero L, C.; Banuelos F, A.; Hernandez D, V. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Paredes G, L., E-mail: fermineutron@yahoo.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2012-06-15

The neutron spectrum and the absorbed dose in a Complementary Metal Oxide Semiconductor (CMOS), has been estimated using Monte Carlo methods. Eventually a person with a pacemaker becomes an oncology patient that must be treated in a linear accelerator. Pacemaker has integrated circuits as CMOS that are sensitive to intense and pulsed radiation fields. Above 7 MV therapeutic beam is contaminated with photoneutrons that could damage the CMOS. Here, the neutron spectrum and the absorbed dose in a CMOS cell was calculated, also the spectra were calculated in two point-like detectors in the room. Neutron spectrum in the CMOS cell shows a small peak between 0.1 to 1 MeV and a larger peak in the thermal region, joined by epithermal neutrons, same features were observed in the point-like detectors. The absorbed dose in the CMOS was 1.522 x 10{sup -17} Gy per neutron emitted by the source. (Author)

Permanent and temporary pacemaker implantation after orthotopic heart transplantation

Directory of Open Access Journals (Sweden)

Bacal Fernando

2000-01-01

Full Text Available PURPOSE:To determine the indication for and incidence and evolution of temporary and permanent pacemaker implantation in cardiac transplant recipients. METHODS: A retrospective review of 114 patients who underwent orthotopic heart transplantation InCor (Heart Institute USP BR between March 1985 and May 1993. We studied the incidence of and indication for temporary pacing, the relationship between pacing and rejection, the need for pemanent pacing and the clinical follow-up. RESULTS: Fourteen of 114 (12%heart transplant recipients required temporary pacing and 4 of 114 (3.5% patients required permanent pacing. The indication for temporary pacing was sinus node dysfunction in 11 patients (78.5% and atrioventricular (AV block in 3 patients (21.4%. The indication for permanent pacemaker implantation was sinus node dysfunction in 3 patients (75% and atrioventricular (AV block in 1 patient (25%. We observed rejection in 3 patients (21.4% who required temporary pacing and in 2 patients (50% who required permanent pacing. The previous use of amiodarone was observed in 10 patients (71.4% with temporary pacing. Seven of the 14 patients (50% died during follow-up. CONCLUSION: Sinus node dysfunction was the principal indication for temporary and permanent pacemaker implantation in cardiac transplant recipients. The need for pacing was related to worse prognosis after cardiac transplantation.

Imunologia do transtorno bipolar Immunology of bipolar disorder

Directory of Open Access Journals (Sweden)

Izabela Guimarães Barbosa

2009-01-01

Full Text Available OBJETIVO: Pesquisas recentes têm implicado fatores imunes na patogênese de diversos transtornos neuropsiquiátricos. O objetivo do presente trabalho é revisar os trabalhos que investigaram a associação entre transtorno bipolar e alterações em parâmetros imunes. MÉTODOS: Artigos que incluíam as palavras-chave: "bipolar disorder", "mania", "immunology", "cytokines", "chemokines", "interleukins", "interferon" e "tumor necrosis factor" foram selecionados em uma revisão sistemática da literatura. As bases de dados avaliadas foram MedLine e Scopus, entre os anos de 1980 e 2008. RESULTADOS: Foram identificados 28 trabalhos que estudaram alterações imunes em pacientes com transtorno bipolar. Seis artigos investigaram genes relacionados à resposta imune; cinco, autoanticorpos; quatro, populações leucocitárias; 13, citocinas e/ou moléculas relacionadas à resposta imune e seis, leucócitos de pacientes in vitro. CONCLUSÕES: Embora haja evidências na literatura correlacionando o transtorno bipolar a alterações imunes, os dados não são conclusivos. O transtorno bipolar parece estar associado a níveis mais elevados de autoanticorpos circulantes, assim como à tendência à ativação imune com produção de citocinas pró-inflamatórias e redução de parâmetros anti-inflamatórios.OBJECTIVE: Emerging research has implicated immune factors in the pathogenesis of a variety of neuropsychiatric disorders. The objective of the present paper is to review the studies that investigated the association between bipolar disorder and immune parameters. METHODS: Papers that included the keywords "bipolar to disorder", "mania", "immunology", "cytokines", "chemokines", "interleukins", "interferon" and "tumor necrosis factor" were selected in a systematic review of the literature. The evaluated databases were MedLine and Scopus in the period between 1980 and 2008. RESULTS: Twenty eight works were found. Six studies investigated immune response

Differences in the ICD-10 diagnostic subtype of depression in bipolar disorder compared to recurrent depressive disorder

DEFF Research Database (Denmark)

Jensen, H.M.; Christensen, E.M.; Kessing, Lars Vedel

2008-01-01

Background: The aim of the study was to investigate whether patients with bipolar depression and patients with recurrent depressive disorder present with different subtypes of depressive episode as according to ICD-10. Sampling and Methods: All patients who got a diagnosis of bipolar affective...... disorder, current episode of depression, or a diagnosis of recurrent depressive disorder, current episode of depression, in a period from 1994 to 2002 at the first outpatient treatment or at the first discharge from psychiatric hospitalization in Denmark were identified in a nationwide register. Results......: Totally, 389 patients got a diagnosis of bipolar disorder, current episode of depression, and 5.391 patients got a diagnosis of recurrent depressive disorder, current episode of depression, at first contact. Compared with patients with a diagnosis of recurrent depressive disorder, patients with bipolar...

Modeling and experimental verification of a fan-folded vibration energy harvester for leadless pacemakers

Science.gov (United States)

Ansari, M. H.; Karami, M. Amin

2016-03-01

This paper studies energy harvesting from heartbeat vibrations for powering leadless pacemakers. Unlike traditional pacemakers, leadless pacemakers are implanted inside the heart and the pacemaker is in direct contact with the myocardium. A leadless pacemaker is in the shape of a cylinder. Thus, in order to utilize the available 3-dimensional space for the energy harvester, we choose a fan-folded 3D energy harvester. The proposed device consists of several piezoelectric beams stacked on top of each other. The volume of the energy harvester is 1 cm3 and its dimensions are 2 cm × 0.5 cm × 1 cm. Although high natural frequency is generally a major concern with micro-scale energy harvesters, by utilizing the fan-folded geometry and adding tip mass and link mass to the configuration, we reduced the natural frequency to the desired range. This fan-folded design makes it possible to generate more than 10 μ W of power per cubic centimeter. The proposed device is compatible with Magnetic Resonance Imaging. Although the proposed device is a linear energy harvester, it is relatively insensitive to the heart rate. The natural frequencies and the mode shapes of the device are calculated analytically. The accuracy of the analytical model is verified by experimental investigations. We use a closed loop shaker system to precisely replicate heartbeat vibrations in vitro.

Bipolar depression: the importance of being on remission Depressão bipolar: a importância da remissão

Directory of Open Access Journals (Sweden)

Fernando Kratz Gazalle

2006-06-01

Full Text Available OBJECTIVE: The aim of the present study is to compare quality of life among currently depressed, subsyndromal and remitted patients with bipolar disorder (BD and to assess whether the level of depression correlates with the scores of quality of life in BD patients. METHOD: Sixty bipolar outpatients diagnosed using the Structured Clinical Interview for DSM-IV who met criteria for diagnosis of BD type I, II or not otherwise specified (BD-NOS, and who were not currently on a manic or mixed episode were included. The main variables of interest were quality of life (QOL assessed using the 26-item World Health Organization QOL instrument (WHOQOL-BREF and depression assessed using the 17-item Hamilton Depression Rating Scale (HDRS. RESULTS: A linear trend test showed a dose response association between patients' current mood state and all domains of quality of life. Higher quality of life scores were found among remitted patients, followed by subsyndromal patients; depressed patients presented lower scores of quality of life, except for the social domain. The four domains of the WHOQOL scale correlated negatively with the HDRS. CONCLUSIONS: Our findings suggest that bipolar depression and residual symptoms of depression are negatively correlated with QOL in BD patients.OBJETIVO: O objetivo deste estudo é o de comparar a qualidade de vida entre pacientes com transtorno bipolar que estão atualmente deprimidos, com depressão subsindrômica e com remissão de sintomas, e avaliar se o nível de depressão tem correlação com os escores de qualidade de vida em pacientes com transtorno bipolar. MÉTODO: Sessenta pacientes bipolares tratados ambulatorialmente, diagnosticados pela Entrevista Clínica Estruturada do DSM-IV, que preencheram critérios diagnósticos de transtorno bipolar tipo I, tipo II ou sem outra especificação (TB-SOE, e que não estavam atualmente em um episódio maníaco ou misto foram incluídos. As principais variáveis de interesse

Genetic structure of personality factors and bipolar disorder in families segregating bipolar disorder.

Science.gov (United States)

Hare, Elizabeth; Contreras, Javier; Raventos, Henriette; Flores, Deborah; Jerez, Alvaro; Nicolini, Humberto; Ontiveros, Alfonso; Almasy, Laura; Escamilla, Michael

2012-02-01

Bipolar disorder (BPD) has been associated with variations in personality dimensions, but the nature of this relationship has been unclear. In this study, the heritabilities of BPD and the Big Five personality factors and the genetic correlations between BPD and personality factors are reported. The participants in this study were 1073 individuals from 172 families of Mexican or Central American ancestry. Heritabilities and genetic correlations were calculated under a polygenic model using the maximum-likelihood method of obtaining variance components implemented in the SOLAR software package. Heritabilities of 0.49, 0.43, and 0.43 were found for the narrowest phenotype (schizoaffective bipolar and bipolar I), the intermediate phenotype (schizoaffective bipolar, bipolar I, and bipolar II), and the broadest phenotype (schizoaffective bipolar, bipolar I, bipolar II, and recurrent depression), respectively. For the Big Five personality factors, heritabilities were 0.25 for agreeableness, 0.24 for conscientiousness, 0.24 for extraversion, 0.23 for neuroticism, and 0.32 for openness to experience. For the narrowest phenotype, a significant negative correlation (-0.32) with extraversion was found. For the broadest phenotype, negative correlations were found for agreeableness (-0.35), conscientiousness (-0.39), and extraversion (-0.44). A positive correlation (0.37) was found with neuroticism. It is not possible to determine whether aspects of personality are factors in the development of bipolar disorder or vice versa. The short form of the NEO does not provide the ability to examine in detail which facets of extraversion are most closely related to bipolar disorder or to compare our results with studies that have used the long version of the scale. This study establishes a partial genetic basis for the Big Five personality factors in this set of families, while the environmental variances demonstrate that non-genetic factors are also important in their influence on

The continuum between Bipolar Disorder and Borderline Personality Disorder.

Science.gov (United States)

Elisei, Sandro; Anastasi, Serena; Verdolini, Norma

2012-09-01

Several studies have been carried out regarding the possible overlap between Bipolar Disorder and borderline personality disorder. Up to now, it is not possible to provide a definitive picture. In fact, there is currently significant debate about the relationship between Borderline Personality Disorder and Bipolar Disorder. MEDLINE searches were performed to identify the latest studies of these disorders, considering psychodynamic aspects. Bipolar disorder and borderline personality disorder share common clinical features, namely affective instability and impulsivity which however differ in quality. Consequently, to better understand these aspects, it is necessary to trace the stages of childhood psychological development. It has been claimed that Bipolar Disorder Type II can be divided into two subtypes: one stable and functional between episodes and one unstable between episodes which is related to Borderline Personality Disorder. However, better diagnostic theories, psychiatrist's empathy and patience remain the essential tool to understand and to face human suffering.

Potential interference of small neodymium magnets with cardiac pacemakers and implantable cardioverter-defibrillators.

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Wolber, Thomas; Ryf, Salome; Binggeli, Christian; Holzmeister, Johannes; Brunckhorst, Corinna; Luechinger, Roger; Duru, Firat

2007-01-01

Magnetic fields may interfere with the function of cardiac pacemakers and implantable cardioverter-defibrillators (ICDs). Neodymium-iron-boron (NdFeB) magnets, which are small in size but produce strong magnetic fields, have become widely available in recent years. Therefore, NdFeB magnets may be associated with an emerging risk of device interference. We conducted a clinical study to evaluate the potential of small NdFeB magnets to interfere with cardiac pacemakers and ICDs. The effect of four NdFeB magnets (two spherical magnets 8 and 10 mm in diameter, a necklace made of 45 spherical magnets, and a magnetic name tag) was tested in forty-one ambulatory patients with a pacemaker and 29 patients with an ICD. The maximum distance at which the magnetic switch of a device was influenced was observed. Magnetic interference was observed in all patients. The maximum distance resulting in device interference was 3 cm. No significant differences were found with respect to device manufacturer and device types. Small NdFeB magnets may cause interference with cardiac pacemakers and ICDs. Patients should be cautioned about the interference risk associated with NdFeB magnets during daily life.

Nutrition and Bipolar Depression.

Science.gov (United States)

Beyer, John L; Payne, Martha E

2016-03-01

As with physical conditions, bipolar disorder is likely to be impacted by diet and nutrition. Patients with bipolar disorder have been noted to have relatively unhealthy diets, which may in part be the reason they also have an elevated risk of metabolic syndrome and obesity. An improvement in the quality of the diet should improve a bipolar patient's overall health risk profile, but it may also improve their psychiatric outcomes. New insights into biological dysfunctions that may be present in bipolar disorder have presented new theoretic frameworks for understanding the relationship between diet and bipolar disorder. Copyright © 2016 Elsevier Inc. All rights reserved.

Measurements of monopolar and bipolar current spreads using forward-masking with a fixed probe.

Science.gov (United States)

Bingabr, Mohamed G; Espinoza-Varas, Blas; Sigdel, Saroj

2014-05-01

This research employed a forward-masking paradigm to estimate the current spread of monopolar (MP) and bipolar (BP) maskers, with current amplitudes adjusted to elicit the same loudness. Since the spatial separation between active and return electrodes is smaller in BP than in MP configurations, the BP current spread is more localized and presumably superior in terms of speech intelligibility. Because matching the loudness requires higher current in BP than in MP stimulation, previous forward-masking studies show that BP current spread is not consistently narrower across subjects or electrodes within a subject. The present forward-masking measures of current spread differ from those of previous studies by using the same BP probe electrode configuration for both MP and BP masker configurations, and adjusting the current levels of the MP and BP maskers so as to match them in loudness. With this method, the estimate of masker current spread would not be contaminated by differences in probe current spread. Forward masking was studied in four cochlear implant patients, two females and two males, with speech recognition scores higher than 50%; that is, their auditory-nerve survival status was more than adequate to carry out the experiments. The data showed that MP and BP masker configurations produce equivalent masking patterns (and current spreads) in three participants. A fourth participant displayed asymmetrical patterns with enhancement rather than masking in some cases, especially when the probe and masker were at the same location. This study showed equivalent masking patterns for MP and BP maskers when the BP masker current amplitude was increased to match the loudness of the MP masker, and the same BP probe configuration is used with both maskers. This finding could help to explain why cochlear implant users often fail to accrue higher speech intelligibility benefit from BP stimulation.

Clinical features and changes in epidemiology of infective endocarditis on pacemaker devices over a 27-year period (1987-2013).

Science.gov (United States)

Carrasco, Francisco; Anguita, Manuel; Ruiz, Martín; Castillo, Juan Carlos; Delgado, Mónica; Mesa, Dolores; Romo, Elias; Pan, Manuel; Suárez de Lezo, Jose

2016-06-01

Use of cardiac pacing devices has grown in recent years. Our aim was to evaluate changes in epidemiology and clinical features of infective endocarditis (IE) involving pacemaker devices in a large series of IE over the last 27 years (1987-2013). From 1987 to December 2013, 413 consecutive IE cases were diagnosed in our hospital. During this period, 7424 pacemaker devices were implanted (6917 pacemakers, 239 implantable cardiac defibrillators, 158 resynchronization devices, and 110 resynchronization/defibrillator devices). All consecutive cases of IE on pacemaker devices were included and analysed. Infective endocarditis on pacemaker devices represented 6.1% of all endocarditis cases (25 patients), affecting 3.6/1000 of all implanted pacemakers. Its proportion increased from 1.25% of all endocarditis in 1987-1993 to 4.08% in 1994-2000, 7.69% in 2001-2007 and 9.32% in 2008-2013 (P pacemaker implants in the period of 1987-1993 to 2.5/1000 in 1994-2000, 3.3/1000 in 2001-2007 and 4.5/1000 implanted devices in 2008-2013 (P pacemaker devices has shown an increasing incidence during the past decades, representing almost 10% of all IE in the last 6 years. This is a severe disease, with a high rate of severe complications and requiring removal of device in most cases. In spite of therapy, early mortality is high. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Low frequency magnetic emissions and resulting induced voltages in a pacemaker by iPod portable music players

Directory of Open Access Journals (Sweden)

Bassen Howard

2008-02-01

Full Text Available Abstract Background Recently, malfunctioning of a cardiac pacemaker electromagnetic, caused by electromagnetic interference (EMI by fields emitted by personal portable music players was highly publicized around the world. A clinical study of one patient was performed and two types of interference were observed when the clinicians placed a pacemaker programming head and an iPod were placed adjacent to the patient's implanted pacemaker. The authors concluded that "Warning labels may be needed to avoid close contact between pacemakers and iPods". We performed an in-vitro study to evaluate these claims of EMI and present our findings of no-effects" in this paper. Methods We performed in-vitro evaluations of the low frequency magnetic field emissions from various models of the Apple Inc. iPod music player. We measured magnetic field emissions with a 3-coil sensor (diameter of 3.5 cm placed within 1 cm of the surface of the player. Highly localized fields were observed (only existing in a one square cm area. We also measured the voltages induced inside an 'instrumented-can' pacemaker with two standard unipolar leads. Each iPod was placed in the air, 2.7 cm above the pacemaker case. The pacemaker case and leads were placed in a saline filled torso simulator per pacemaker electromagnetic compatibility standard ANSI/AAMI PC69:2000. Voltages inside the can were measured. Results Emissions were strongest (≈ 0.2 μT pp near a few localized points on the cases of the two iPods with hard drives. Emissions consisted of 100 kHz sinusoidal signal with lower frequency (20 msec wide pulsed amplitude modulation. Voltages induced in the iPods were below the noise level of our instruments (0.5 mV pp in the 0 – 1 kHz band or 2 mV pp in the 0 – 5 MHz bandwidth. Conclusion Our measurements of the magnitude and the spatial distribution of low frequency magnetic flux density emissions by 4 different models of iPod portable music players. Levels of less than 0.2 �

Parametric and cycle tests of a 40-AH bipolar nickel-hydrogen battery

Science.gov (United States)

Cataldo, R. L.

1986-01-01

The performance of a 12 V, 40 ampere-hour bipolar battery during various charge current, discharge current, temperature, and pressure operating conditions is investigated. The cell voltages, temperatures, ampere-hours, and watt-hours derived from the charge/discharge cycle tests are studied. Consideration is given to battery voltage and discharge capacity as a function of discharge current, the correlation between energy delivered on a discharge and battery temperature, battery voltage response to pulse discharges, and the voltage-temperature relationship. The data reveal that the bipolar Ni-H battery is applicable to high power systems.

Characterization of a right atrial subsidiary pacemaker and acceleration of the pacing rate by HCN over-expression.

Science.gov (United States)

Morris, Gwilym M; D'Souza, Alicia; Dobrzynski, Halina; Lei, Ming; Choudhury, Moinuddin; Billeter, Rudi; Kryukova, Yelena; Robinson, Richard B; Kingston, Paul A; Boyett, Mark R

2013-10-01

Although the right atrium (RA contains subsidiary atrial pacemaker (SAP) tissue that can take over from the sinoatrial node (SAN) in sick sinus syndrome (SSS), SAP tissue is bradycardic. Little is known about SAP tissue and one aim of the study was to characterize ion channel expression to obtain insight into SAP pacemaker mechanisms. A second aim was to determine whether HCN over-expression (a 'biopacemaker'-like strategy) can accelerate the pacemaker rate producing a pacemaker that is similar in nature to the SAN. SAP tissue was isolated from the rat and the leading pacemaker site was characterized. Cell size at the leading pacemaker site in the SAP was smaller than in the RA and comparable to that in the SAN. mRNA levels showed the SAP to be similar to, but distinct from, the SAN. For example, in the SAN and SAP, expression of Tbx3 and HCN1 was higher and Nav1.5 and Cx43 lower than in the RA. Organ-cultured SAP tissue beat spontaneously, but at a slower rate than the SAN. Adenovirus-mediated gene transfer of HCN2 and the chimeric protein HCN212 significantly increased the pacemaker rate of the SAP close to that of the native SAN, but HCN4 was ineffective. SAP tissue near the inferior vena cava is bradycardic, but shares characteristics with the SAN. Pacing can be accelerated by the over-expression of HCN2 or HCN212. This provides proof of concept for the use of SAP tissue as a substrate for biopacemaking in the treatment of SSS.

Experimental evidence of a chaotic region in a neural pacemaker

Energy Technology Data Exchange (ETDEWEB)

Gu, Hua-Guang, E-mail: guhuaguang@tongji.edu.cn [School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092 (China); Department of Electronic Engineering, City University of Hong Kong, Hong Kong SAR (China); Jia, Bing [School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092 (China); Chen, Guan-Rong [Department of Electronic Engineering, City University of Hong Kong, Hong Kong SAR (China)

2013-03-15

In this Letter, we report the finding of period-adding scenarios with chaos in firing patterns, observed in biological experiments on a neural pacemaker, with fixed extra-cellular potassium concentration at different levels and taken extra-cellular calcium concentration as the bifurcation parameter. The experimental bifurcations in the two-dimensional parameter space demonstrate the existence of a chaotic region interwoven with the periodic region thereby forming a period-adding sequence with chaos. The behavior of the pacemaker in this region is qualitatively similar to that of the Hindmarsh–Rose neuron model in a well-known comb-shaped chaotic region in two-dimensional parameter spaces.

Properties of Bipolar Fuzzy Hypergraphs

OpenAIRE

Akram, M.; Dudek, W. A.; Sarwar, S.

2013-01-01

In this article, we apply the concept of bipolar fuzzy sets to hypergraphs and investigate some properties of bipolar fuzzy hypergraphs. We introduce the notion of $A-$ tempered bipolar fuzzy hypergraphs and present some of their properties. We also present application examples of bipolar fuzzy hypergraphs.

Bipolar Affective Disorder and Migraine

Directory of Open Access Journals (Sweden)

Birk Engmann

2012-01-01

Full Text Available This paper consists of a case history and an overview of the relationship, aetiology, and treatment of comorbid bipolar disorder migraine patients. A MEDLINE literature search was used. Terms for the search were bipolar disorder bipolar depression, mania, migraine, mood stabilizer. Bipolar disorder and migraine cooccur at a relatively high rate. Bipolar II patients seem to have a higher risk of comorbid migraine than bipolar I patients have. The literature on the common roots of migraine and bipolar disorder, including both genetic and neuropathological approaches, is broadly discussed. Moreover, bipolar disorder and migraine are often combined with a variety of other affective disorders, and, furthermore, behavioural factors also play a role in the origin and course of the diseases. Approach to treatment options is also difficult. Several papers point out possible remedies, for example, valproate, topiramate, which acts on both diseases, but no first-choice treatments have been agreed upon yet.

PreBötzinger complex and pacemaker neurons: hypothesized site and kernel for respiratory rhythm generation

DEFF Research Database (Denmark)

Rekling, J C; Feldman, J L

1998-01-01

Identification of the sites and mechanisms underlying the generation of respiratory rhythm is of longstanding interest to physiologists and neurobiologists. Recently, with the development of novel experimental preparations, especially in vitro en bloc and slice preparations of rodent brainstem, p...... activity of pacemaker or group-pacemaker neurons....

Lifetime anxiety disorder and current anxiety symptoms associated with hastened depressive recurrence in bipolar disorder.

Science.gov (United States)

Shah, Saloni; Kim, Jane P; Park, Dong Yeon; Kim, Hyun; Yuen, Laura D; Do, Dennis; Dell'Osso, Bernardo; Hooshmand, Farnaz; Miller, Shefali; Wang, Po W; Ketter, Terence A

2017-09-01

To assess differential relationships between lifetime anxiety disorder/current anxiety symptoms and longitudinal depressive severity in bipolar disorder (BD). Stanford BD Clinic outpatients enrolled during 2000-2011 were assessed with the Systematic Treatment Enhancement Program for BD (STEP-BD) Affective Disorders Evaluation and followed with the STEP-BD Clinical Monitoring Form while receiving naturalistic treatment for up to two years. Baseline unfavorable illness characteristics/current mood symptoms and times to depressive recurrence/recovery were compared in patients with versus without lifetime anxiety disorder/current anxiety symptoms. Among 105 currently recovered patients, lifetime anxiety disorder was significantly associated with 10/27 (37.0%) demographic/other unfavorable illness characteristics/current mood symptoms/current psychotropics, hastened depressive recurrence (driven by earlier onset age), and a significantly (> two-fold) higher Kaplan-Meier estimated depressive recurrence rate, whereas current anxiety symptoms were significantly associated with 10/27 (37.0%) demographic/other unfavorable illness characteristics/current mood symptoms/current psychotropics and hastened depressive recurrence (driven by lifetime anxiety disorder), but only a numerically higher Kaplan-Meier estimated depressive recurrence rate. In contrast, among 153 currently depressed patients, lifetime anxiety disorder/current anxiety symptoms were not significantly associated with time to depressive recovery or depressive recovery rate. American tertiary BD clinic referral sample, open naturalistic treatment. Research is needed regarding differential relationships between lifetime anxiety disorder and current anxiety symptoms and hastened/delayed depressive recurrence/recovery - specifically whether lifetime anxiety disorder versus current anxiety symptoms has marginally more robust association with hastened depressive recurrence, and whether both have marginally more robust

From Pacemaker to Wearable: Techniques for ECG Detection Systems.

Science.gov (United States)

Kumar, Ashish; Komaragiri, Rama; Kumar, Manjeet

2018-01-11

With the alarming rise in the deaths due to cardiovascular diseases (CVD), present medical research scenario places notable importance on techniques and methods to detect CVDs. As adduced by world health organization, technological proceeds in the field of cardiac function assessment have become the nucleus and heart of all leading research studies in CVDs in which electrocardiogram (ECG) analysis is the most functional and convenient tool used to test the range of heart-related irregularities. Most of the approaches present in the literature of ECG signal analysis consider noise removal, rhythm-based analysis, and heartbeat detection to improve the performance of a cardiac pacemaker. Advancements achieved in the field of ECG segments detection and beat classification have a limited evaluation and still require clinical approvals. In this paper, approaches on techniques to implement on-chip ECG detector for a cardiac pacemaker system are discussed. Moreover, different challenges regarding the ECG signal morphology analysis deriving from medical literature is extensively reviewed. It is found that robustness to noise, wavelet parameter choice, numerical efficiency, and detection performance are essential performance indicators required by a state-of-the-art ECG detector. Furthermore, many algorithms described in the existing literature are not verified using ECG data from the standard databases. Some ECG detection algorithms show very high detection performance with the total number of detected QRS complexes. However, the high detection performance of the algorithm is verified using only a few datasets. Finally, gaps in current advancements and testing are identified, and the primary challenge remains to be implementing bullseye test for morphology analysis evaluation.

Rupture of a pacemaker lead during the course of infective endocarditis.

Science.gov (United States)

Akgüllü, Çağdaş; Eryılmaz, Ufuk; Kurtoğlu, Tünay; Özpelit, Ebru

2013-01-01

A 23-year-old male who had a VDDR pacemaker implanted seven years ago due to sick sinus syndrome and recurrent syncope episodes was admitted with symptoms of dyspnea, fever, and tachycardia, which were present for a few days. He was suspected to be suffering from pneumonia and underwent computed tomography scanning of the thorax, which revealed widespread infiltration in the lung parenchyma and pulmonary emboli. Transthoracic echocardiography revealed an extremely mobile echogenic structure in the right atrium, which was determined to be the free portion of a ruptured pacemaker lead. There was an overlying thrombus and/or vegetation-like organized soft tissue within the right ventricle around the lead component. In this article, the rupture of a permanent pacemaker lead, which complicated the course of infective endocarditis associated with pulmonary embolism and pneumonia is reported. We hypothesize that the underlying mechanism for the rupture is soft tissue entrapment within the right ventricle. Unfortunately, this rare and life-threatening situation led to the death of our patient after the surgical removal of the device and its components.

Tilt-table testing of patients with pacemaker and recurrent syncope

DEFF Research Database (Denmark)

Nielsen, Christian E. Haarmark; Kanters, Jørgen K; Mehlsen, Jesper

2016-01-01

responses accounting for 72% of patients with a positive test. There were no differences between groups with positive or negative test result regarding age, gender, resting blood pressure and heart rate, daily fluid intake, pacing mode, pacing indication or pacing rhythm at rest. HUT in patients...... protocol with nitroglycerine provocation was used and the test results were classified according to current guidelines. Baseline data were retrieved from the medical records. Overall, 54% of patients had a positive response to HUT. Vasodepressor or orthostatic hypotensive response were the most prevalent...... with pacemakers has a high diagnostic yield. Although, the majority of patients had a vasodepressor or orthostatic hypotensive response, cardioinhibitory response leading to syncope was also seen....

Design and development of bipolar 4-quadrant switch-mode power converter for superconducting magnets

International Nuclear Information System (INIS)

Yashwant Kumar; Thakur, S.K.; Ghosh, M.K.; Tiwari, T.P.; De, Anirban; Kumari, S.; Saha, S.

2011-01-01

A uniform zero crossing magnetic field in a magnet can be achieved by using bipolar power converter with four quadrant operation. A high current bipolar switch-mode power converter (rated ±27 V max , ±7V flat top, ±300A, 100 ppm) has been designed and developed indigenously at VECC Kolkata. Four quadrants operation is accomplished by using power IGBTs in an H-bridge configuration with switching frequency around 20 kHz. The switch-mode power converter is used because of high dynamic response, low output ripple, high efficiency and low input current harmonics. In this paper, circuit topology, function of system components and key system specifications of high current bipolar switch mode power converter is discussed. (author)

Computer modeling of electrical and thermal performance during bipolar pulsed radiofrequency for pain relief

International Nuclear Information System (INIS)

Pérez, Juan J.; Pérez-Cajaraville, Juan J.; Muñoz, Víctor; Berjano, Enrique

2014-01-01

Purpose: Pulsed RF (PRF) is a nonablative technique for treating neuropathic pain. Bipolar PRF application is currently aimed at creating a “strip lesion” to connect the electrode tips; however, the electrical and thermal performance during bipolar PRF is currently unknown. The objective of this paper was to study the temperature and electric field distributions during bipolar PRF. Methods: The authors developed computer models to study temperature and electric field distributions during bipolar PRF and to assess the possible ablative thermal effect caused by the accumulated temperature spikes, along with any possible electroporation effects caused by the electrical field. The authors also modeled the bipolar ablative mode, known as bipolar Continuous Radiofrequency (CRF), in order to compare both techniques. Results: There were important differences between CRF and PRF in terms of electrical and thermal performance. In bipolar CRF: (1) the initial temperature of the tissue impacts on temperature progress and hence on the thermal lesion dimension; and (2) at 37 °C, 6-min of bipolar CRF creates a strip thermal lesion between the electrodes when these are separated by a distance of up to 20 mm. In bipolar PRF: (1) an interelectrode distance shorter than 5 mm produces thermal damage (i.e., ablative effect) in the intervening tissue after 6 min of bipolar RF; and (2) the possible electroporation effect (electric fields higher than 150 kV m −1 ) would be exclusively circumscribed to a very small zone of tissue around the electrode tip. Conclusions: The results suggest that (1) the clinical parameters considered to be suitable for bipolar CRF should not necessarily be considered valid for bipolar PRF, and vice versa; and (2) the ablative effect of the CRF mode is mainly due to its much greater level of delivered energy than is the case in PRF, and therefore at same applied energy levels, CRF, and PRF are expected to result in same outcomes in terms of thermal

Computer modeling of electrical and thermal performance during bipolar pulsed radiofrequency for pain relief

Energy Technology Data Exchange (ETDEWEB)

Pérez, Juan J. [Instituto de Investigación Interuniversitario en Bioingeniería y Tecnología Orientada al Ser Humano, Universitat Politècnica de València, Valencia 46022 (Spain); Pérez-Cajaraville, Juan J. [Pain Unit and Department of Anesthesia and Critical Care, Clínica Universidad de Navarra, University of Navarra, Pamplona 31008 (Spain); Muñoz, Víctor [Neurotherm Spain, Barcelona 08303 (Spain); Berjano, Enrique, E-mail: eberjano@eln.upv.es [Biomedical Synergy, Electronic Engineering Department, Universitat Politècnica de València 46022 (Spain)

2014-07-15

Purpose: Pulsed RF (PRF) is a nonablative technique for treating neuropathic pain. Bipolar PRF application is currently aimed at creating a “strip lesion” to connect the electrode tips; however, the electrical and thermal performance during bipolar PRF is currently unknown. The objective of this paper was to study the temperature and electric field distributions during bipolar PRF. Methods: The authors developed computer models to study temperature and electric field distributions during bipolar PRF and to assess the possible ablative thermal effect caused by the accumulated temperature spikes, along with any possible electroporation effects caused by the electrical field. The authors also modeled the bipolar ablative mode, known as bipolar Continuous Radiofrequency (CRF), in order to compare both techniques. Results: There were important differences between CRF and PRF in terms of electrical and thermal performance. In bipolar CRF: (1) the initial temperature of the tissue impacts on temperature progress and hence on the thermal lesion dimension; and (2) at 37 °C, 6-min of bipolar CRF creates a strip thermal lesion between the electrodes when these are separated by a distance of up to 20 mm. In bipolar PRF: (1) an interelectrode distance shorter than 5 mm produces thermal damage (i.e., ablative effect) in the intervening tissue after 6 min of bipolar RF; and (2) the possible electroporation effect (electric fields higher than 150 kV m{sup −1}) would be exclusively circumscribed to a very small zone of tissue around the electrode tip. Conclusions: The results suggest that (1) the clinical parameters considered to be suitable for bipolar CRF should not necessarily be considered valid for bipolar PRF, and vice versa; and (2) the ablative effect of the CRF mode is mainly due to its much greater level of delivered energy than is the case in PRF, and therefore at same applied energy levels, CRF, and PRF are expected to result in same outcomes in terms of

Computer modeling of electrical and thermal performance during bipolar pulsed radiofrequency for pain relief.

Science.gov (United States)

Pérez, Juan J; Pérez-Cajaraville, Juan J; Muñoz, Víctor; Berjano, Enrique

2014-07-01

Pulsed RF (PRF) is a nonablative technique for treating neuropathic pain. Bipolar PRF application is currently aimed at creating a "strip lesion" to connect the electrode tips; however, the electrical and thermal performance during bipolar PRF is currently unknown. The objective of this paper was to study the temperature and electric field distributions during bipolar PRF. The authors developed computer models to study temperature and electric field distributions during bipolar PRF and to assess the possible ablative thermal effect caused by the accumulated temperature spikes, along with any possible electroporation effects caused by the electrical field. The authors also modeled the bipolar ablative mode, known as bipolar Continuous Radiofrequency (CRF), in order to compare both techniques. There were important differences between CRF and PRF in terms of electrical and thermal performance. In bipolar CRF: (1) the initial temperature of the tissue impacts on temperature progress and hence on the thermal lesion dimension; and (2) at 37 °C, 6-min of bipolar CRF creates a strip thermal lesion between the electrodes when these are separated by a distance of up to 20 mm. In bipolar PRF: (1) an interelectrode distance shorter than 5 mm produces thermal damage (i.e., ablative effect) in the intervening tissue after 6 min of bipolar RF; and (2) the possible electroporation effect (electric fields higher than 150 kV m(-1)) would be exclusively circumscribed to a very small zone of tissue around the electrode tip. The results suggest that (1) the clinical parameters considered to be suitable for bipolar CRF should not necessarily be considered valid for bipolar PRF, and vice versa; and (2) the ablative effect of the CRF mode is mainly due to its much greater level of delivered energy than is the case in PRF, and therefore at same applied energy levels, CRF, and PRF are expected to result in same outcomes in terms of thermal damage zone dimension.

Hemodynamic instability after pulmonary veins isolation in a patient with dual chamber pacemaker: The phantom injury of the ventricular lead.

Science.gov (United States)

Kiuchi, Márcio Galindo; Lobato, Guilherme Miglioli; Chen, Shaojie

2017-06-01

The standard treatment of sinus node dysfunction (SND) is the pacemaker implantation, and the ideal methodology for the management of atrial fibrillation (AF) is rhythm control, but this is sometimes very hard to accomplish. For such actions, complete isolation of all pulmonary veins (PVI) is currently widely accepted as the best endpoint. In this case, we report a female patient, 81 years old, with controlled hypertension, without coronary artery disease, bearer of bilateral knee replacement, and dual chamber pacemaker implanted 1.5 years ago owing to sinus node disease, presenting the following symptoms: presyncope episodes associated with sustained irregular palpitation tachycardia. The evaluation of the pacemaker-recorded episodes of atrial fibrillation, the echocardiogram-presented normal systolic function and measurements, as well as the resting myocardial scintigraphy and with drug use did not demonstrate ischemia and/or fibrosis. The patient was in use of valsartan 320 mg daily, amlodipine 10 mg daily, sotalol hydrochloride 120 mg 2 times daily, and dabigatran 110 mg 2 times daily. At the end of the PVI, the patient presented hemodynamic instability, with a decrease in heart rate to 30 bpm and invasive arterial blood pressure to 60/30 mmHg. The pericardial puncture was quickly carried out with the possibility of cardiac tamponade as the first hypothesis, but no pericardial effusion was found. Next, we detected acute capture loss from the ventricular pacemaker lead, unvarying with high voltage and pulse width, even with stable impedance, sense and keeping the same position visualized by fluoroscopy. And there was soon afterwards induction of sustained ventricular tachycardia degenerating to spontaneous ventricular fibrillation. Electrical cardioversion-defibrillation was performed with 200J, and the sinus rhythm was reestablished, but there was a dead short, and the pacemaker generator was burned and disabled. So, we can speculate that

Physiological effects of light on the human circadian pacemaker

Science.gov (United States)

Shanahan, T. L.; Czeisler, C. A.

2000-01-01

The physiology of the human circadian pacemaker and its influence and on the daily organization of sleep, endocrine and behavioral processes is an emerging interest in science and medicine. Understanding the development, organization and fundamental properties underlying the circadian timing system may provide insight for the application of circadian principles to the practice of clinical medicine, both diagnostically (interpretation of certain clinical tests are dependent on time of day) and therapeutically (certain pharmacological responses vary with the time of day). The light-dark cycle is the most powerful external influence acting upon the human circadian pacemaker. It has been shown that timed exposure to light can both synchronize and reset the phase of the circadian pacemaker in a predictable manner. The emergence of detectable circadian rhythmicity in the neonatal period is under investigation (as described elsewhere in this issue). Therefore, the pattern of light exposure provided in the neonatal intensive care setting has implications. One recent study identified differences in both amount of sleep time and weight gain in infants maintained in a neonatal intensive care environment that controlled the light-dark cycle. Unfortunately, neither circadian phase nor the time of day has been considered in most clinical investigations. Further studies with knowledge of principles characterizing the human circadian timing system, which governs a wide array of physiological processes, are required to integrate these findings with the practice of clinical medicine.

Transtorno bipolar de início tardio: uma variedade orgânica do transtorno de humor? Bipolar disorder with late onset: an organic variety of mood disorder?

Directory of Open Access Journals (Sweden)

Osvaldo P Almeida

2004-10-01

Full Text Available Transtorno bipolar (TB é comumente associado à fase final da adolescência ou idade adulta jovem, embora em uma proporção substancial dos pacientes a doença comece em fases mais tardias da vida. Os resultados de várias investigações clínicas sugerem que casos de transtorno bipolar com início tardio têm, mais freqüentemente, uma "causa orgânica" e que isso justificaria a subdivisão do transtorno bipolar entre "início precoce" e "início tardio". Este artigo revê a literatura sobre a hipótese orgânica do transtorno bipolar de início tardio e conclui que essa subdivisão é artificial e carece de suporte clínico e epidemiológico.Bipolar disorder (BD is commonly associated with late adolescence or early adulthood, although a substantial proportion of patients develops the condition in later life. The results of early clinical investigations suggested that cases of bipolar disorder with onset in later life were more often associated with 'organic causes', and could potentially justify the distinction between early and late onset bipolar disorder. This paper reviews currently available evidence in support of the organic hypothesis for late onset bipolar disorder. It concludes that the split of bipolar disorder according to age at onset is artificial, and lacks clinical significance and epidemiological support.

Bipolar zinc/oxygen battery development

Energy Technology Data Exchange (ETDEWEB)

Mueller, S [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Schlatter, C [Swiss Federal Inst. of Technology, Lausanne (Switzerland)

1997-06-01

A bipolar electrically rechargeable Zn/O{sub 2} battery has been developed. Reticulated copper foam served as substrate for the zinc deposit on the anodic side, and La{sub 0.6}Ca{sub 0.4}CoO{sub 3}-catalyzed bifunctional oxygen electrodes were used on the cathodic side of the cells. The 100 cm{sup 2} unit cell had an open circuit voltage of 1,4 V(O{sub 2}) in moderately alkaline electrolyte. The open circuit voltage and the peak power measured for a stack containing seven cells were ca. 10V and 90W, respectively. The current-potential behaviour was determined as a function of the number of bipolar cells, and the maximum discharge capacity was determined at different discharge rates. (author) 4 figs., 1 ref.

ON BIPOLAR SINGLE VALUED NEUTROSOPHIC GRAPHS

OpenAIRE

Said Broumi; Mohamed Talea; Assia Bakali; Florentin Smarandache

2016-01-01

In this article, we combine the concept of bipolar neutrosophic set and graph theory. We introduce the notions of bipolar single valued neutrosophic graphs, strong bipolar single valued neutrosophic graphs, complete bipolar single valued neutrosophic graphs, regular bipolar single valued neutrosophic graphs and investigate some of their related properties.

Risk of pacemaker implantation after uneventful successful cavotricuspid isthmus radiofrequency ablation in patients with common atrial flutter.

Science.gov (United States)

Rodríguez-Mañero, Moisés; González-Melchor, Layla; Ballesteros, Gabriel; Raposeiras-Roubín, Sergio; García-Seara, Javier; López, Xesús Alberte Fernández; Cambeiro, Cristina González; Alcalde, Oscar; García-Bolao, Ignacio; Martínez-Sande, Luis; González-Juanatey, José Ramón

2016-01-01

Little is known about the risk of pacemaker implantation after common atrial flutter ablation in the long-term. We retrospectively reviewed the electrophysiology laboratory database at two Spanish University Hospitals from 1998 to 2012 to identify patients who had undergone successful ablation for cavotricuspid dependent atrial flutter. Cox regression analysis was used to examine the risk of pacemaker implantation. A total of 298 patients were considered eligible for inclusion. The mean age of the enrolled patients was 65.7±11. During 57.7±42.8 months, 30 patients (10.1%) underwent pacemaker implantation. In the stepwise multivariate models only heart rate at the time of the ablation (OR: 0.96; 95% CI: 0.93-0.98; ppacemaker implantation. A heart rate of ≤65 bpm was identified as the optimal cut-off value to predict the need of pacemaker implantation in the follow-up (sensitivity: 79%, specificity: 74%) by ROC curve analyses. This is the first study of an association between the slow conducting common atrial flutter and subsequent risk of pacemaker implantation. In light of these findings, assessing it prior to ablation can be helpful for the risk stratification of sinus node disease or atrioventricular conduction disease requiring a pacemaker implantation in patients with persistent atrial flutter. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Pacemaker reed switch behavior in 0.5, 1.5, and 3.0 Tesla magnetic resonance imaging units: are reed switches always closed in strong magnetic fields?

Science.gov (United States)

Luechinger, Roger; Duru, Firat; Zeijlemaker, Volkert A; Scheidegger, Markus B; Boesiger, Peter; Candinas, Reto

2002-10-01

MRI is established as an important diagnostic tool in medicine. However, the presence of a cardiac pacemaker is usually regarded as a contraindication for MRI due to safety reasons. The aim of this study was to investigate the state of a pacemaker reed switch in different orientations and positions in the main magnetic field of 0.5-, 1.5-, and 3.0-T MRI scanners. Reed switches used in current pacemakers and ICDs were tested in 0.5-, 1.5-, and 3.0-T MRI scanners. The closure of isolated reed switches was evaluated for different orientations and positions relative to the main magnetic field. The field strengths to close and open the reed switch and the orientation dependency of the closed state inside the main magnetic field were investigated. The measurements were repeated using two intact pacemakers to evaluate the potential influence of the other magnetic components, like the battery. If the reed switches were oriented parallel to the magnetic fields, they closed at 1.0 +/- 0.2 mT and opened at 0.7 +/- 0.2 mT. Two different reed switch behaviors were observed at different magnetic field strengths. In low magnetic fields ( 200 mT), the reed switches opened in 50% of all tested orientations. No difference between the three scanners could be demonstrated. The reed switches showed the same behavior whether they were isolated or an integral part of the pacemakers. The reed switch in a pacemaker or an ICD does not necessarily remain closed in strong magnetic fields at 0.5, 1.5, or 3.0 T and the state of the reed switch may not be predictable with certainty in clinical situations.

A new bipolar RRAM selector based on anti-parallel connected diodes for crossbar applications

International Nuclear Information System (INIS)

Li, Yingtao; Gong, Qingchun; Li, Rongrong; Jiang, Xinyu

2014-01-01

Crossbar arrays are the most promising application of a resistive random access memory (RRAM) device for achieving high density memory. However, cross-talk interference in the crossbar array limits the increase in the integration density. In this paper, the combination of two anti-parallel connected diodes and a bipolar RRAM cell is proposed to suppress the sneak current in a crossbar array with anti-parallel connected diodes as the selector for the bipolar RRAM. By using the anti-parallel connected diodes as a selector, the sneak current can be effectively suppressed and the high density crossbar array of more than 1 Mb can be realized as estimated by the 1/2V read voltage scheme. These results indicate that anti-parallel connected diodes can be used as a bipolar selector and have great potential for high density bipolar RRAM crossbar array applications. (papers)

Systematic review of the prevalence of bipolar disorder and bipolar spectrum disorders in population-based studies

Directory of Open Access Journals (Sweden)

José Caetano Dell'Aglio Jr.

2013-01-01

Full Text Available This paper describes the findings of a systematic literature review aimed at providing an overview of the lifetime prevalence of bipolar disorder and bipolar spectrum disorders in population-based studies. Databases MEDLINE, ProQuest, Psychnet, and Web of Science were browsed for papers published in English between 1999 and May 2012 using the following search string: bipolar disorders OR bipolar spectrum disorders AND prevalence OR cross-sectional OR epidemiology AND population-based OR non-clinical OR community based. The search yielded a total of 434 papers, but only those published in peer-reviewed journals and with samples aged ≥ 18 years were included, resulting in a final sample of 18 papers. Results revealed rather heterogeneous findings concerning the prevalence of bipolar disorders and bipolar spectrum disorders. Lifetime prevalence of bipolar disorder ranged from 0.1 to 7.5%, whereas lifetime prevalence of bipolar spectrum disorders ranged from 2.4 to 15.1%. Differences in the rates of bipolar disorder and bipolar spectrum disorders may be related to the consideration of subthreshold criteria upon diagnosis. Differences in the prevalence of different subtypes of the disorder are discussed in light of diagnostic criteria and instruments applied.

Modeling the dual pacemaker system of the tau mutant hamster.

Science.gov (United States)

Oda, G A; Menaker, M; Friesen, W O

2000-06-01

Circadian pacemakers in many animals are compound. In rodents, a two-oscillator model of the pacemaker composed of an evening (E) and a morning (M) oscillator has been proposed based on the phenomenon of "splitting" and bimodal activity peaks. The authors describe computer simulations of the pacemaker in tau mutant hamsters viewed as a system of mutually coupled E and M oscillators. These mutant animals exhibit normal type 1 PRCs when released into DD but make a transition to a type 0 PRC when held for many weeks in DD. The two-oscillator model describes particularly well some recent behavioral experiments on these hamsters. The authors sought to determine the relationships between oscillator amplitude, period, PRC, and activity duration through computer simulations. Two complementary approaches proved useful for analyzing weakly coupled oscillator systems. The authors adopted a "distinct oscillators" view when considering the component E and M oscillators and a "system" view when considering the system as a whole. For strongly coupled systems, only the system view is appropriate. The simulations lead the authors to two primary conjectures: (1) the total amplitude of the pacemaker system in tau mutant hamsters is less than in the wild-type animals, and (2) the coupling between the unit E and M oscillators is weakened during continuous exposure of hamsters to DD. As coupling strength decreases, activity duration (alpha) increases due to a greater phase difference between E and M. At the same time, the total amplitude of the system decreases, causing an increase in observable PRC amplitudes. Reduced coupling also increases the relative autonomy of the unit oscillators. The relatively autonomous phase shifts of E and M oscillators can account for both immediate compression and expansion of activity bands in tau mutant and wild-type hamsters subjected to light pulses.

Peripheral blood brain-derived neurotrophic factor in bipolar disorder

DEFF Research Database (Denmark)

Munkholm, K; Vinberg, M; Kessing, L V

2016-01-01

Peripheral blood brain-derived neurotrophic factor (BDNF) has been proposed as a potential biomarker related to disease activity and neuroprogression in bipolar disorder, speculated to mirror alterations in brain expression of BDNF. The research area is rapidly evolving; however, recent...... investigations have yielded conflicting results with substantial variation in outcomes, highlighting the need to critically assess the state of current evidence. The aims of the study were to investigate differences in peripheral blood BDNF concentrations between bipolar disorder patients and healthy control...... subjects and between affective states in bipolar disorder patients, including assessment of the effect of treatment of acute episodes on BDNF levels. A systematic review of English language studies without considering publication status was conducted in PubMed (January 1950-November 2014), Embase (1974...

Scientific attitudes towards bipolar disorders

Directory of Open Access Journals (Sweden)

Mohammad-Hossein Biglu

2014-02-01

Full Text Available Introduction: Bipolar disorder is a psychiatric condition that is also called manic-depressive disease. It causes unusual changes in mood, energy, activity levels, and the ability to carry out day-to-day tasks. In the present study, 3 sets of data were considered and analyzed: first, all papers categorized under Bipolar Disorders in Science Citation Index Expanded (SCI-E database through 2001-2011; second, papers published by the international journal of Bipolar Disorders indexed in SCI-E during a period of 11 years; and third, all papers distributed by the international journal of Bipolar Disorders indexed in MEDLINE during the period of study. Methods: The SCI-E database was used to extract all papers indexed with the topic of Bipolar Disorders as well as all papers published by The International Journal of Bipolar Disorders. Extraction of data from MEDLINE was restricted to the journals name from setting menu. The Science of Science Tool was used to map the co-authorship network of papers published by The International Journal of Bipolar Disorders through 2009-2011. Results: Analysis of data showed that the majority of publications in the subject area of bipolar disorders indexed in SCI-E were published by The International Journal of Bipolar Disorders. Although journal articles consisted of 59% of the total publication type in SCI-E, 65% of publications distributed by The Journal of Bipolar Disorders were in the form of meetingabstracts. Journal articles consisted of only 23% of the total publications. USA was the leading country regarding sharing data in the field of bipolar disorders followed by England, Canada, and Germany. Conclusion: The editorial policy of The International Journal of Bipolar Disorders has been focused on new themes and new ways of researching in the subject area of bipolar disorder. Regarding the selection of papers for indexing, the SCI-E database selects data more comprehensively than MEDLINE. The number of papers

Bipolar and unipolar resistive switching behaviors of sol–gel-derived SrTiO3 thin films with different compliance currents

International Nuclear Information System (INIS)

Tang, M H; Wang, Z P; Zeng, Z Q; Xu, X L; Wang, G Y; Zhang, L B; Xiao, Y G; Yang, S B; Jiang, B; Li, J C; He, J

2011-01-01

The SrTiO 3 (STO) thin films on a Pt/Ti/SiO 2 /Si substrate were synthesized using a sol–gel method to form a metal–insulator–metal structure. This device shows the bipolar resistance switching (BRS) behavior for a compliance current I cc of less than 0.1 mA but exhibits soft breakdown at a higher level of compliance current. A transition from the BRS behavior to the stable unipolar resistive switching behavior (URS) was also observed. We found that the BRS behavior may be controlled by the structure interface while the URS behavior is likely bulk controlled. Our study indicates that the external compliance current is a key factor in resistance switching phenomenon of STO thin films

Psychosocial aspects and mental health in children after permanent pacemaker implantation

DEFF Research Database (Denmark)

Andersen, C; Hørder, K; Kristensen, L

1994-01-01

-14). Generally the psychological condition was strained in 7 families, in which psychiatric and social therapy had been necessary. The children's intelligence was within normal ranges, average IQ being 110 (range 80-135). The children had abnormal body image related to the pacemaker. Adults virtually incorporate......, and they were given a child-psychiatric evaluation consisting of a semi-structured and a child-psychiatric interview. The psychological interview used intelligence tests and the Draw-A-Person test as well as the Rorschach test. The patients had had their pacemakers during an average of 6.7 years (range 3...

Interference of neodymium magnets with cardiac pacemakers and implantable cardioverter-defibrillators: an in vitro study.

Science.gov (United States)

Ryf, Salome; Wolber, Thomas; Duru, Firat; Luechinger, Roger

2008-01-01

Permanent magnets may interfere with the function of cardiac pacemakers and implantable cardioverter-defibrillators (ICDs). Neodymium-iron-boron (NdFeB) magnets have become widely available in recent years and are incorporated in various articles of daily life. We conducted an in-vitro study to evaluate the ability of NdFeB magnets for home and office use to cause interference with cardiac pacemakers and ICDs. The magnetic fields of ten NdFeB magnets of different size and shape were measured at increasing distances beginning from the surface until a field-strength (B-field) value of 0.5 mT was reached. Furthermore, for each magnet the distance was determined at which a sample pacemaker switched from magnet mode to normal mode. Depending on the size and remanence of individual magnets, a B-field value of 0.5 mT was found at distances ranging from 1.5 cm to 30 cm and a value of 1 mT at distances from 1 cm to 22 cm. The pacemaker behavior was influenced at distances from 1 cm to 24 cm. NdFeB magnets for home and office use may cause interference with cardiac pacemakers and ICDs at distances up to 24 centimeters. Patient education and product declarations should include information about the risk associated with these magnets.

Circadian locomotor rhythms in the cricket, Gryllodes sigillatus. II. Interactions between bilaterally paired circadian pacemakers.

Science.gov (United States)

Ushirogawa, H; Abe, Y; Tomioka, K

1997-10-01

The optic lobe is essential for circadian locomotor rhythms in the cricket, Gryllodes sigillatus. We examined potential interactions between the bilaterally paired optic lobes in circadian rhythm generation. When one optic lobe was removed, the free-running period of the locomotor rhythm slightly but significantly lengthened. When exposed to light-dark cycles (LD) with 26 hr period, intact and sham operated animals were clearly entrained to the light cycle, but a large number of animals receiving unilateral optic nerve severance showed rhythm dissociation. In the dissociation, two rhythmic components appeared; one was readily entrained to the given LD and the other free-ran with a period shorter than 24 hr, and activity was expressed only when they were inphase. The period of the free-running component was significantly longer than that of the animals with a single blinded pacemaker kept in LD13:13, suggesting that the pacemaker on the intact side had some influence on the blinded pacemaker even in the dissociated state. The ratio of animals with rhythm dissociation was greater with the lower light intensity of the LD. The results suggest that the bilaterally distributed pacemakers are only weakly coupled to one another but strongly suppress the activity driven by the partner pacemaker during their subjective day. The strong suppression of activity would be advantageous to keep a stable nocturnality for this cricket living indoors.

A review of factors associated with greater likelihood of suicide attempts and suicide deaths in bipolar disorder: Part II of a report of the International Society for Bipolar Disorders Task Force on Suicide in Bipolar Disorder.

Science.gov (United States)

Schaffer, Ayal; Isometsä, Erkki T; Azorin, Jean-Michel; Cassidy, Frederick; Goldstein, Tina; Rihmer, Zoltán; Sinyor, Mark; Tondo, Leonardo; Moreno, Doris H; Turecki, Gustavo; Reis, Catherine; Kessing, Lars Vedel; Ha, Kyooseob; Weizman, Abraham; Beautrais, Annette; Chou, Yuan-Hwa; Diazgranados, Nancy; Levitt, Anthony J; Zarate, Carlos A; Yatham, Lakshmi

2015-11-01

Many factors influence the likelihood of suicide attempts or deaths in persons with bipolar disorder. One key aim of the International Society for Bipolar Disorders Task Force on Suicide was to summarize the available literature on the presence and magnitude of effect of these factors. A systematic review of studies published from 1 January 1980 to 30 May 2014 identified using keywords 'bipolar disorder' and 'suicide attempts or suicide'. This specific paper examined all reports on factors putatively associated with suicide attempts or suicide deaths in bipolar disorder samples. Factors were subcategorized into: (1) sociodemographics, (2) clinical characteristics of bipolar disorder, (3) comorbidities, and (4) other clinical variables. We identified 141 studies that examined how 20 specific factors influenced the likelihood of suicide attempts or deaths. While the level of evidence and degree of confluence varied across factors, there was at least one study that found an effect for each of the following factors: sex, age, race, marital status, religious affiliation, age of illness onset, duration of illness, bipolar disorder subtype, polarity of first episode, polarity of current/recent episode, predominant polarity, mood episode characteristics, psychosis, psychiatric comorbidity, personality characteristics, sexual dysfunction, first-degree family history of suicide or mood disorders, past suicide attempts, early life trauma, and psychosocial precipitants. There is a wealth of data on factors that influence the likelihood of suicide attempts and suicide deaths in people with bipolar disorder. Given the heterogeneity of study samples and designs, further research is needed to replicate and determine the magnitude of effect of most of these factors. This approach can ultimately lead to enhanced risk stratification for patients with bipolar disorder. © The Royal Australian and New Zealand College of Psychiatrists 2015.

A review of factors associated with greater likelihood of suicide attempts and suicide deaths in bipolar disorder: Part II of a report of the International Society for Bipolar Disorders Task Force on Suicide in Bipolar Disorder

Science.gov (United States)

Schaffer, Ayal; Isometsä, Erkki T; Azorin, Jean-Michel; Cassidy, Frederick; Goldstein, Tina; Rihmer, Zoltán; Sinyor, Mark; Tondo, Leonardo; Moreno, Doris H; Turecki, Gustavo; Reis, Catherine; Kessing, Lars Vedel; Ha, Kyooseob; Weizman, Abraham; Beautrais, Annette; Chou, Yuan-Hwa; Diazgranados, Nancy; Levitt, Anthony J; Zarate, Carlos A; Yatham, Lakshmi

2018-01-01

Objectives Many factors influence the likelihood of suicide attempts or deaths in persons with bipolar disorder. One key aim of the International Society for Bipolar Disorders Task Force on Suicide was to summarize the available literature on the presence and magnitude of effect of these factors. Methods A systematic review of studies published from 1 January 1980 to 30 May 2014 identified using keywords ‘bipolar disorder’ and ‘suicide attempts or suicide’. This specific paper examined all reports on factors putatively associated with suicide attempts or suicide deaths in bipolar disorder samples. Factors were subcategorized into: (1) sociodemographics, (2) clinical characteristics of bipolar disorder, (3) comorbidities, and (4) other clinical variables. Results We identified 141 studies that examined how 20 specific factors influenced the likelihood of suicide attempts or deaths. While the level of evidence and degree of confluence varied across factors, there was at least one study that found an effect for each of the following factors: sex, age, race, marital status, religious affiliation, age of illness onset, duration of illness, bipolar disorder subtype, polarity of first episode, polarity of current/recent episode, predominant polarity, mood episode characteristics, psychosis, psychiatric comorbidity, personality characteristics, sexual dysfunction, first-degree family history of suicide or mood disorders, past suicide attempts, early life trauma, and psychosocial precipitants. Conclusion There is a wealth of data on factors that influence the likelihood of suicide attempts and suicide deaths in people with bipolar disorder. Given the heterogeneity of study samples and designs, further research is needed to replicate and determine the magnitude of effect of most of these factors. This approach can ultimately lead to enhanced risk stratification for patients with bipolar disorder. PMID:26175498

Bipolar Disorder.

Science.gov (United States)

Spearing, Melissa

Bipolar disorder, a brain disorder that causes unusual shifts in a person's mood, affects approximately one percent of the population. It commonly occurs in late adolescence and is often unrecognized. The diagnosis of bipolar disorder is made on the basis of symptoms, course of illness, and when possible, family history. Thoughts of suicide are…

Do current national and international guidelines have specific recommendations for older adults with bipolar disorder?

DEFF Research Database (Denmark)

Dols, Annemiek; Kessing, Lars Vedel; Strejilevich, Sergio A

2016-01-01

a variety of sources have become available in recent years. It is expected that at least some of this emerging information on OABD would be incorporated into treatment guidelines available to clinicians around the world. METHODS: The International Society of Bipolar Disorders OABD task force compiled...... and compared recommendations from current national and international guidelines that specifically address geriatric or older individuals with BD (from year 2005 onwards). RESULTS: There were 34 guidelines, representing six continents and 19 countries. The majority of guidelines had no separate section on OABD....... General principles for treating OABD with medication are recommended to be similar to those for younger adults, with special caution for side effects due to somatic comorbidity and concomitant medications. Therapeutic lithium serum levels are suggested to be lower but recommendations are very general...

Study on incidence of pulmonary embolism in patients with cardiac pacemakers using lung perfusion mapping and ventilation scanning

International Nuclear Information System (INIS)

Yamashina, Hideki; Higo, Masanori; Sueda, Takashi

1990-01-01

We investigated pulmonary perfusion mapping and ventilation scanning employing 99mTC-MMA and 81mKr-Gas in patients with DDD and VVI cardiac pacemaker implantation. In 51 cases among 175 patients we observed some defects which matched the results from lung perfusion scanning in the pulmonary segments and sub-segments. These were diagnosed as pulmonary embolism after the possibility of other pulmonary diseases was rejected. The incidence rate of pulmonary embolism in patients with VVI (Ventricular pacing/sensing, inhibited type) pacemakers was 47 out of 138, or 34.1%, especially for those who received a pulmonary scanning examination whithin 6 months after pacemaker implantation. In contrast, those who were examined after 6 months had lower rates as well as chronological factors. The incidence rate of pulmonary embolism in 37 patients with DDD (Double chamber pacing/sensing, double modes of response) pacemakers was 10.8%, considerably lower than that for patients with VVI pacemakers. Therefore, one main factor of pulmonary embolism in patients with pacemakers could be the non-physiological phase of the contractions of both atria and ventricles. Other factors, such as the presence of foreign bodies in the endocardium, aging, and hypertension, could also promote pulmonary embolism. (author)

Study on the ELDRS of bipolar linear operational amplifier

International Nuclear Information System (INIS)

Yang Hui; Liu Yanfang; Chen Yu; Bai Hua; Zhang Dong

2011-01-01

Bipolar linear devices laboratory irradiation testing results are significantly different from the actual in flight exposure to the radiation. In this paper the total dose irradiation of operational amplifiers, and analysis upon the total dose response of these bipolar circuits under the different test conditions were investigated in the same experiment. Total dose tests of bipolar linear operational amplifiers show susceptible to dose rate, bias and room temperature annealing during exposure. The critical sensitive parameters of operational amplifier are input bias current, input offset current, input offset voltage, and open loop gain, which exhibits both bias and dose rate dependence. With calculating the change of each electrical parameter (Δpara) for each sample at 300 Gy radiation level, it has been found that ratio of the Δpara at low dose rate to the Δpara at high dose rate exceeds 2.46 times for any of the parameters. So these parts are considered to be ELDRS susceptible. After room temperature annealing, the main parameters have time dependence effect at low dose rate and without time dependent effect at high dose rate. (authors)

Generation of metal composition gradients by means of bipolar electrodeposition

International Nuclear Information System (INIS)

Tisserant, Gwendoline; Fattah, Zahra; Ayela, Cédric; Roche, Jérome; Plano, Bernard; Zigah, Dodzi; Goudeau, Bertrand; Kuhn, Alexander; Bouffier, Laurent

2015-01-01

Highlights: • A bipolar electrochemistry approach for the preparation of surface gradients is reported. • Several metals are simultaneously deposited on a bipolar electrode. • The elemental composition and thickness of the deposit varies alongside the bipolar electrode. • The deposit affects the surface properties and exhibits a barcode feature. - Abstract: Bipolar electrochemistry is an unconventional technique that currently encounters a renewal of interest due to modern applications in the fields of analytical chemistry or materials science. The approach is particularly relevant for the preparation of asymmetric objects or surfaces such as Janus particles for example. Bipolar electrochemistry allows spatially controlled deposition of various layers from electroactive precursors, selectively at one side of a bipolar electrode. We report here the concomitant cathodic deposition of up to three different metals at the same time in a single experiment. The deposits were characterized by optical and electron microscopy imaging as well as profilometry and energy dispersive X-ray spectroscopy. As a result, the deposited layer is composed of several areas exhibiting both a composition and a thickness gradient. Such a variation directly modifies the optical and electronic properties alongside the surface and gives access to the design of composite surfaces exhibiting a visual gradient feature.

Trends in service time of pacemakers in the Netherlands: A long-term nationwide follow-up study

NARCIS (Netherlands)

L.M. de Vries (Laura); M.J.G. Leening (Maarten); W.A. Dijk (Arnold); C.A.M. Hooijschuur (C. A M); B.H.Ch. Stricker (Bruno); N.M. van Hemel (Norbert)

2017-01-01

textabstractAims After decades of experience and strongly improved technology, service time of pacemaker generators is expected to increase. To test this hypothesis, we conducted a retrospective review of a large cohort of patients with a pacemaker. Methods We reviewed data collected between 1984

Nanosecond bipolar pulse generators for bioelectrics.

Science.gov (United States)

Xiao, Shu; Zhou, Chunrong; Yang, Enbo; Rajulapati, Sambasiva R

2018-04-26

Biological effects caused by a nanosecond pulse, such as cell membrane permeabilization, peripheral nerve excitation and cell blebbing, can be reduced or cancelled by applying another pulse of reversed polarity. Depending on the degree of cancellation, the pulse interval of these two pulses can be as long as dozens of microseconds. The cancellation effect diminishes as the pulse duration increases. To study the cancellation effect and potentially utilize it in electrotherapy, nanosecond bipolar pulse generators must be made available. An overview of the generators is given in this paper. A pulse forming line (PFL) that is matched at one end and shorted at the other end allows a bipolar pulse to be produced, but no delay can be inserted between the phases. Another generator employs a combination of a resistor, an inductor and a capacitor to form an RLC resonant circuit so that a bipolar pulse with a decaying magnitude can be generated. A third generator is a converter, which converts an existing unipolar pulse to a bipolar pulse. This is done by inserting an inductor in a transmission line. The first phase of the bipolar pulse is provided by the unipolar pulse's rising phase. The second phase is formed during the fall time of the unipolar pulse, when the inductor, which was previously charged during the flat part of the unipolar pulse, discharges its current to the load. The fourth type of generator uses multiple MOSFET switches stacked to turn on a pre-charged, bipolar RC network. This approach is the most flexible in that it can generate multiphasic pulses that have different amplitudes, delays, and durations. However, it may not be suitable for producing short nanosecond pulses (<100 ns), whereas the PFL approach and the RLC approach with gas switches are used for this range. Thus, each generator has its own advantages and applicable range. Copyright © 2018 Elsevier B.V. All rights reserved.

Measuring dose from radiotherapy treatments in the vicinity of a cardiac pacemaker.

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Peet, Samuel C; Wilks, Rachael; Kairn, Tanya; Crowe, Scott B

2016-12-01

This study investigated the dose absorbed by tissues surrounding artificial cardiac pacemakers during external beam radiotherapy procedures. The usefulness of out-of-field reference data, treatment planning systems, and skin dose measurements to estimate the dose in the vicinity of a pacemaker was also examined. Measurements were performed by installing a pacemaker onto an anthropomorphic phantom, and using radiochromic film and optically stimulated luminescence dosimeters to measure the dose in the vicinity of the device during the delivery of square fields and clinical treatment plans. It was found that the dose delivered in the vicinity of the cardiac device was unevenly distributed both laterally and anteroposteriorly. As the device was moved distally from the square field, the dose dropped exponentially, in line with out-of-field reference data in the literature. Treatment planning systems were found to substantially underestimate the dose for volumetric modulated arc therapy, helical tomotherapy, and 3D conformal treatments. The skin dose was observed to be either greater or lesser than the dose received at the depth of the device, depending on the treatment site, and so care should be if skin dose measurements are to be used to estimate the dose to a pacemaker. Square field reference data may be used as an upper estimate of absorbed dose per monitor unit in the vicinity of a cardiac device for complex treatments involving multiple gantry angles. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Zero-fluoroscopy permanent pacemaker implantation using Ensite NavX system: Clinical viability or fanciful technique?

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Guo, Ping; Qiu, Jie; Wang, Yan; Chen, Guangzhi; Proietti, Riccardo; Fadhle, Al-Selmi; Zhao, Chunxia; Wen Wang, Dao

2018-02-01

Fluoroscopy is the imaging modality routinely used for cardiac device implantation and electrophysiological procedures. Due to the rising concern regarding the harmful effects of radiation exposure to both the patients and operation staffs, novel 3D mapping systems have been developed and implemented in electrophysiological procedure for the navigation of catheters inside the heart chambers. Their applicability in cardiac device implantation has been rarely reported. Our aim is to evaluate the feasibility and safety of permanent pacemaker implantation without fluoroscopy. From January 2012 to June 2016, six patients (50 ± 15 years, four of six were female, one of who was at the 25th week of gestation) who underwent permanent pacemaker implantation were included (zero-fluoroscopy group). Data from 20 consecutive cases of implantation performed under fluoroscopy guidance were chosen as a control group (fluoroscopy group). Total implantation procedure time for single-chamber pacemaker was 51.3 ± 13.1 minutes in the zero-fluoroscopy group and 42.6 ± 7.4 minutes in the fluoroscopy group (P  =  0.155). The implantation procedural time for a dual-chamber pacemaker was 88.3 ± 19.6 minutes and 67.3 ± 7.6 minutes in the zero-fluoroscopy and fluoroscopy groups (P  =  0.013), respectively. No complications were observed during the procedure and the follow-up in the two groups, and all pacemakers worked with satisfactory parameters. Ensite NavX system can be used as a reliable and safe zero-fluoroscopy approach for the implantation of single- or dual-chamber permanent pacemakers in specific patients, such as pregnant women or in extreme situations when the x-ray machine is not available. © 2017 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals, Inc.

Pacemaker and radiotherapy in breast cancer: is targeted intraoperative radiotherapy the answer in this setting?

International Nuclear Information System (INIS)

Keshtgar, Mohammed RS; Eaton, David J; Reynolds, Claire; Pigott, Katharine; Davidson, Tim; Gauter-Fleckenstein, Benjamin; Wenz, Frederik

2012-01-01

We present the case of an 83 year old woman with a cardiac pacemaker located close in distance to a subsequently diagnosed invasive ductal carcinoma of the left breast. Short range intraoperative radiotherapy was given following wide local excision and sentinel node biopsy. The challenges of using ionising radiation with pacemakers is also discussed

Bipolar polygenic loading and bipolar spectrum features in major depressive disorder

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Wiste, Anna; Robinson, Elise B; Milaneschi, Yuri; Meier, Sandra; Ripke, Stephan; Clements, Caitlin C; Fitzmaurice, Garrett M; Rietschel, Marcella; Penninx, Brenda W; Smoller, Jordan W; Perlis, Roy H

2014-01-01

Objectives Family and genetic studies indicate overlapping liability for major depressive disorder and bipolar disorder. The purpose of this study was to determine whether this shared genetic liability influences clinical presentation. Methods A polygenic risk score for bipolar disorder, derived from a large genome-wide association meta-analysis, was generated for each subject of European–American ancestry (n = 1,274) in the Sequential Treatment Alternatives to Relieve Depression study (STAR*D) outpatient major depressive disorder cohort. A hypothesis-driven approach was used to test for association between bipolar disorder risk score and features of depression associated with bipolar disorder in the literature. Follow-up analyses were performed in two additional cohorts. Results A generalized linear mixed model including seven features hypothesized to be associated with bipolar spectrum illness was significantly associated with bipolar polygenic risk score [F = 2.07, degrees of freedom (df) = 7, p = 0.04). Features included early onset, suicide attempt, recurrent depression, atypical depression, subclinical mania, subclinical psychosis, and severity. Post-hoc univariate analyses demonstrated that the major contributors to this omnibus association were onset of illness at age ≤ 18 years [odds ratio (OR) = 1.2, p = 0.003], history of suicide attempt (OR = 1.21, p = 0.03), and presence of at least one manic symptom (OR = 1.16, p = 0.02). The maximal variance in these traits explained by polygenic score ranged from 0.8–1.1%. However, analyses in two replication cohorts testing a five feature model did not support this association. Conclusions Bipolar genetic loading appeared to be associated with bipolar-like presentation in major depressive disorder in the primary analysis. However, results are at most inconclusive because of lack of replication. Replication efforts are challenged by different ascertainment and assessment strategies in the different cohorts

Parental communication style and family relationships in children of bipolar parents.

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Vance, Yvonne H; Huntley Jones, Steven; Espie, Jonathan; Bentall, Richard; Tai, Sara

2008-09-01

To examine relationships between parental communication styles and family environment in parents with bipolar disorder (BD) and their children (CBP). On measures of parental communication styles and family environment, 20 BD parents and their 23 children (CBP) were compared to controls. Children completed a current mood measure. BD parents endorsed more negative communication styles and were less expressive than controls. CBP presented with more current or lifetime mood disorder diagnoses than control children (CC). Current depressive mood was associated with different perceptions of family environment for both CBP and CC. This familial high risk design indicated differences in family environment, parenting style, and in children of bipolar parents' perception of their family environment as it relates to their current mood.

Relationship between Childhood Maltreatment, Suicidality, and Bipolarity: A Retrospective Study

OpenAIRE

Park, Young-Min

2017-01-01

Objective The aims of current study were to determine whether childhood maltreatment contributes to the occurrence of major depressive disorder (MDD) with bipolarity or suicidality. Methods In total, 132 outpatients diagnosed with MDD between 2014 and 2015 on the medical records were included. The subjects were divided into two groups according to the presence of childhood maltreatment (CM group) and no childhood maltreatment (NCM group). Depression severity and bipolarity were identified usi...

In-wire measurement of the neutron dose rate on patients with 238Pu pacemakers implanted

International Nuclear Information System (INIS)

Piesch, E.; Burgkhardt, B.; Kollmeier, W.

1975-01-01

In-vivo measurements of the neutron dose on Medtronic pacemakers have been performed by using a proportional counter and a scintillation counter. The paper discusses the technique of free air and phantom calibration and the method of in-vivo measurement of the neutron fluence and the estimation of the dose equivalent. The neutron dose equivalent rate measured on seven patients with 238 Pu pacemakers implanted were found to be (5.6+-0.1) mRem/h at the surface of the pacemaker in 1.25 cm distance from the center of the source corresponding to a neutron emission rate of 940 ns -1 . The results are in good agreement with results of other methods reported by different authors. (Auth.)

Sikkerhed af magnetisk resonans-skanning hos patienter med pacemaker og implanterbar defibrillator

DEFF Research Database (Denmark)

Al-Sabagh, Kifah Hekmat; Christensen, Britta Ege; Thøgersen, Anna Margrethe

2010-01-01

The presence of a cardiac implantable device is ICD considered an absolute contraindication to magnetic resonance imaging (MRI). The purpose of this study was to evaluate the safety of performing MRI in patients with cardiac pacemakers and ICDs that had a compelling clinical need for MRI examinat......The presence of a cardiac implantable device is ICD considered an absolute contraindication to magnetic resonance imaging (MRI). The purpose of this study was to evaluate the safety of performing MRI in patients with cardiac pacemakers and ICDs that had a compelling clinical need for MRI...

Permanent Pacemaker-Induced Superior Vena Cava Syndrome: Successful Treatment by Endovascular Stent

International Nuclear Information System (INIS)

Lanciego, Carlos; Rodriguez, Mario; Rodriguez, Adela; Carbonell, Miguel A.; Garcia, Lorenzo Garcia

2003-01-01

The use of metallic stents in the management of benign and malignant superior vena cava syndrome (SVCS) is well documented. Symptomatic stenosis or occlusion of the SVC is a rare complication of a transvenous permanent pacemaker implant. Suggested treatments have included anticoagulation therapy, thrombolysis, balloon angioplasty and surgery. More recently, endovascular stenting has evolved as an attractive alternative but the data available in the literature are limited. We describe a case in which venous stenting with a Wallstent endoprosthesis was used successfully. The patient remains symptom free and with normal pacemaker function 36 months later

Universal pacemaker of genome evolution.

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Snir, Sagi; Wolf, Yuri I; Koonin, Eugene V

2012-01-01

A fundamental observation of comparative genomics is that the distribution of evolution rates across the complete sets of orthologous genes in pairs of related genomes remains virtually unchanged throughout the evolution of life, from bacteria to mammals. The most straightforward explanation for the conservation of this distribution appears to be that the relative evolution rates of all genes remain nearly constant, or in other words, that evolutionary rates of different genes are strongly correlated within each evolving genome. This correlation could be explained by a model that we denoted Universal PaceMaker (UPM) of genome evolution. The UPM model posits that the rate of evolution changes synchronously across genome-wide sets of genes in all evolving lineages. Alternatively, however, the correlation between the evolutionary rates of genes could be a simple consequence of molecular clock (MC). We sought to differentiate between the MC and UPM models by fitting thousands of phylogenetic trees for bacterial and archaeal genes to supertrees that reflect the dominant trend of vertical descent in the evolution of archaea and bacteria and that were constrained according to the two models. The goodness of fit for the UPM model was better than the fit for the MC model, with overwhelming statistical significance, although similarly to the MC, the UPM is strongly overdispersed. Thus, the results of this analysis reveal a universal, genome-wide pacemaker of evolution that could have been in operation throughout the history of life.

Genetics Home Reference: bipolar disorder

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... Email Facebook Twitter Home Health Conditions Bipolar disorder Bipolar disorder Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Bipolar disorder is a mental health condition that causes extreme ...

Infection and twiddler syndrome in a dog with addison's disease, complete heart block, and wandering artificial pacemakers

International Nuclear Information System (INIS)

Hill, R.C.; Buchanan, J.W.

1990-01-01

Third degree heart block developed in an obese, 10-year-old Labrador retriever with adrenocortical failure. A permanent transthoracic pacemaker was fitted, but the pulse generator migrated 2 years later, to the ventral part of the flank, where an abscess formed. A new pacemaker was fitted, but also migrated and rotated and a syndrome analogous to Twiddler's syndrome in man developed. After a further 2 years the second pacemaker was located, encapsulated within the right pleural cavity. Culture of the brownish exudate around the pulse generator yielded Pseudomonas sp

A Cross-sectional, Comparative Study of Insight in Schizophrenia and Bipolar Patients in Remission.

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Ramachandran, Arul Saravanan; Ramanathan, Rajkumar; Praharaj, Samir Kumar; Kanradi, Haridas; Sharma, Podila Satya Venkata Narasimha

2016-01-01

To study insight correlates in schizophrenia and bipolar mood disorder in remission among out-patients attending the Psychiatry Department of a Tertiary Care Hospital. In a cross-sectional, naturalistic study, adult patients with schizophrenia and bipolar mood disorder in remission (n = 80; schizophrenia-40, mania-20, bipolar depression-20) were compared on insight measures and clinical correlates. Scale to Assess the Unawareness of Mental Disorders (SUMD) was used as the main tool to assess current and past measures of insight. Hogan's Drug Attitude Inventory was used to assess the drug attitude and compliance. Positive and Negative Symptom Scale for Schizophrenia, Young's Mania Rating Scale, and HAMD were used to rate psychopathology. Clinical Global Improvement was used as a screening tool for remission. For comparison of the three clinical groups, analysis of variance and Chi-square test were used. In the post-hoc analysis, the Ryan-Einot-Gabriel-Welsch test was used to find the group difference. About 40% in the schizophrenia group were unaware of their mental illness as against none in the bipolar group. The awareness of mental disorder for the current period, the awareness of the achieved effects of medications, and the awareness of social consequence was better in the bipolar group. The drug attitude (compliant positive attitude) increased as the SUMD item scale decreased or in other words, as the insight improved. Insight, both current and retrospect, showed significant differences between the schizophrenia and bipolar patients. Insight is significantly correlated with the observed compliance and drug attitude of the patient groups.

Prophylactic antibiotic for pacemaker surgery: what is optimal ...

African Journals Online (AJOL)

One of them, a bed-ridden patient developed severe pocket infection necessitating explantation and replacement 3 weeks later. Conclusions: We noted with satisfaction that short regime of prophylactic parentral ceftriaxone is effective in preventing pacemaker infection and there is no need for the long regimen. Niger Med J.

Complex regional pain syndrome type I following pacemaker implantation

Directory of Open Access Journals (Sweden)

Sangita Kamath

2015-12-01

Full Text Available A 70-year-old woman presented with burning pain and swelling over dorsum of right hand and small joints of the fingers, associated with redness, feeling of warmth, and stiffness of the fingers, with inability to bend the fingers since 2 months. The symptoms were progressively increasing in intensity for the past 1 month. There was no history of fever or trauma to the hand. Two months before her symptoms started, she had permanent pacemaker implanted for complete heart block with syncope. She was hypertensive and was on regular medication. Her X-ray of right hand showed decreased bone density (demineralisation, suggestive of osteopenia. A diagnosis of reflex sympathetic dystrophy syndrome or complex regional pain syndrome type I induced by pacemaker insertion was made. She was treated with amitriptyline and steroids, after which her symptoms improved dramatically.

Feasibility and safety of adenosine cardiovascular magnetic resonance in patients with MR conditional pacemaker systems at 1.5 Tesla.

Science.gov (United States)

Klein-Wiele, Oliver; Garmer, Marietta; Urbien, Rhyan; Busch, Martin; Kara, Kaffer; Mateiescu, Serban; Grönemeyer, Dietrich; Schulte-Hermes, Michael; Garbrecht, Marc; Hailer, Birgit

2015-12-22

Cardiovascular Magnetic Resonance (CMR) with adenosine stress is a valuable diagnostic tool in coronary artery disease (CAD). However, despite the development of MR conditional pacemakers CMR is not yet established in clinical routine for pacemaker patients with known or suspected CAD. A possible reason is that adenosine stress perfusion for ischemia detection in CMR has not been studied in patients with cardiac conduction disease requiring pacemaker therapy. Other than under resting conditions it is unclear whether MR safe pacing modes (paused pacing or asynchronous mode) can be applied safely because the effect of adenosine on heart rate is not precisely known in this entity of patients. We investigate for the first time feasibility and safety of adenosine stress CMR in pacemaker patients in clinical routine and evaluate a pacing protocol that considers heart rate changes under adenosine. We retrospectively analyzed CMR scans of 24 consecutive patients with MR conditional pacemakers (mean age 72.1 ± 11.0 years) who underwent CMR in clinical routine for the evaluation of known or suspected CAD. MR protocol included cine imaging, adenosine stress perfusion and late gadolinium enhancement. Pacemaker indications were sinus node dysfunction (n = 18) and second or third degree AV block (n = 6). Under a pacing protocol intended to avoid competitive pacing on the one hand and bradycardia due to AV block on the other no arrhythmia occurred. Pacemaker stimulation was paused to prevent competitive pacing in sinus node dysfunction with resting heart rate >45 bpm. Sympatho-excitatory effect of adenosine led to a significant acceleration of heart rate by 12.3 ± 8.3 bpm (p pacemakers. Heart rate response to adenosine has to be considered for the choice of pacing modes during CMR.