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Sample records for automatic defibrillator implantation

  1. [The implantable automatic cardioverter-defibrillator].

    PubMed

    Klein, H; Tröster, J; Trappe, H J; Becht, I; Siclari, F

    1990-04-01

    In addition to medical treatment for ventricular tachyarrhythmias which has not proven to be sufficient, nonmedical modes of treatment are available such as electrophysiologically-guided surgical measures and catheter ablation, both of which are restricted to only a relatively small patient population and require further technical refinement. In 1980, Mirowski introduced the automatic implantable defibrillator and, to date, world-wide, this device has been implanted in 8000 patients. CHARACTERISTICS AND IMPLANTATION OF THE AUTOMATIC IMPLANTABLE CARDIOVERTER/DEFIBRILLATOR (AICD): The AICD continuously monitors the electrical activity of the heart, recognizes the onset of threatening ventricular tachycardias and terminates these according to the respectively programmed mode by delivering direct current shocks or stimuli. The currently used defibrillators consist of an impulse generator with lithium batteries and an electrode system. The batteries can charge a capacitor with about 700 volts in five to eight seconds which produces a current with an energy up to 30 Joules on discharge. The current is delivered either by two plate electrodes on the right and left ventricles or a plate electrode on the left ventricle and a spiral electrode inserted in the superior vena cava. The electrodes also serve the purpose of tachycardia detection by means of an electrical signal, the probability density function (PDF), that is, a significant decrease in the potentials to isoelectric. With this, it is only possible to terminate ventricular fibrillation. Additional electrical detection criteria are obtained and analyzed by two adjacently positioned epicardial screw electrodes or a bipolar endocardial electrode, enable identification of ventricular tachycardia as well. If the tachycardia detection criteria are fulfilled, the capacitor is discharged according to its programmed shock energy. In 1988, programmable defibrillators were introduced. Current defibrillator treatment also

  2. Patient ECG recording control for an automatic implantable defibrillator

    NASA Technical Reports Server (NTRS)

    Fountain, Glen H. (Inventor); Lee, Jr., David G. (Inventor); Kitchin, David A. (Inventor)

    1986-01-01

    An implantable automatic defibrillator includes sensors which are placed on or near the patient's heart to detect electrical signals indicative of the physiology of the heart. The signals are digitally converted and stored into a FIFO region of a RAM by operation of a direct memory access (DMA) controller. The DMA controller operates transparently with respect to the microprocessor which is part of the defibrillator. The implantable defibrillator includes a telemetry communications circuit for sending data outbound from the defibrillator to an external device (either a patient controller or a physician's console or other) and a receiver for sensing at least an externally generated patient ECG recording command signal. The patient recording command signal is generated by the hand held patient controller. Upon detection of the patient ECG recording command, DMA copies the contents of the FIFO into a specific region of the RAM.

  3. Epicardial Automatic Implantable Cardiac Defibrillator In A Child With Symptomatic Bugada Syndrome

    PubMed Central

    Moltedo, Jose M; Abello, Mauricio; Gustavo, Sivori; Javier, Celada; Delucis, Pablo Garcia

    2011-01-01

    An 18 month old 14 kg male with symptomatic Brugada syndrome underwent placement of an epicardial automatic implantable cardiac defibrillator using a single coil transvenous lead sutured to the anterolateral aspect of the left ventricle. PMID:21760684

  4. Silicone Breast Implant and Automatic Implantable Cardioverter Defibrillator: Can They Coexist? A Case Report

    PubMed Central

    Arik, Zaretski

    2016-01-01

    Summary: We present a case of a silicone breast implant rupture after insertion of an automatic implantable cardioverter defibrillator (AICD). A 51-year-old woman presented to our plastic surgery clinic to exchange her silicone breast implants. The patient underwent cosmetic mastopexy and breast augmentation in 2008. Because of recurrent myocardial infarctions and chronic heart failure, she underwent an insertion of an AICD in 2014 in which the left breast implant was hit. In this report, we discuss the first case of an AICD insertion, disrupting a breast implant. This case report illustrates the rare but real possibility of breast implant rupture after even minor surgical manipulation of the breast area. PMID:27622117

  5. [The automatic implantable cardioverter-defibrillator for prevention of sudden heart death in children and adolescents].

    PubMed

    Paul, T; Luhmer, I; Trappe, H J; Klein, H; Fieguth, H G; Brauer, C; Scharpwinkel, U; Kallfelz, H C

    1993-08-01

    Little experience exists with the automatic implantable cardioverter-defibrillator in the pediatric population. Since 1990, an automatic implantable cardioverter defibrillator was implanted in four young patients (mean age 15.8 years, mean body weight 53.3 kg) with life-threatening ventricular tachyarrhythmias at our institution. In three patients, a cardiac anomaly was evident (dilated cardiomyopathy, status post Rastelli operation for complex transposition of the great arteries, status post atrial switch for transposition of the great arteries), the last patient had a normal cardiac anatomy. Indications for implantation were resuscitation from documented hypotensive ventricular tachycardia in one patient and recurrent syncope of suspected cardiac origin in the remaining three patients. At preimplantation electrophysiological study, all four patients had inducible ventricular tachycardia and/or ventricular fibrillation. At implantation of the cardioverter defibrillator in the operating theatre, the ventricular tachyarrhythmias were again induced and terminated reliably by the device. After a mean follow-up of 13 months, three of the four patients had appropriate discharges without syncope or resuscitation. The automatic implantable cardioverter-defibrillator appears to be a feasible and effective therapy also in pediatric patients for prevention of sudden cardiac death due to ventricular tachyarrhythmias.

  6. [Implantation of an automatic cardioverter-defibrillator in small children--two case reports].

    PubMed

    Przybylski, Andrzej; Kucińska, Beata; Grabowski, Krzysztof; Sterliński, Maciej; Wróblewska-Kałuzewska, Maria; Szwed, Hanna

    2004-07-01

    Implantation of an automatic cardioverter-defibrillator (ICD) in children may be challenging due to the increased risk of periprocedural and long-term complications. ICD was implanted in two boys with hypertrophic cardiomyopathy, aged 6 and 9 years, with of a body weight of 20 and 25 kg, respectively. In one patient an ICD was implanted due to a history of ventricular fibrillation whereas the second patient underwent prophylactic ICD implantation due to a family history of sudden cardiac death. No short- or mid-term complications were recorded. Difficulties and risks of ICD implantation in children are discussed.

  7. Cosmetic approach for placement of the automatic implantable cardioverter-defibrillator in young women.

    PubMed

    Curiale, S; Rosenfeld, L E; Elefteriades, J A

    1991-12-01

    A surgical approach is described for a more cosmetically acceptable placement of the automatic implantable cardioverter-defibrillator in young women. The transvenous sensing lead and the vena caval spring electrode are placed through a small subclavicular incision. The left ventricular patch electrode is placed through an anterior minithoracotomy in the crease under the left breast. A small transverse incision in the left lower quadrant is used to place the generator under the external oblique fascia in the low abdominal wall. Minimal cosmetic impairment from incisions and hardware results.

  8. Implantable cardioverter-defibrillator

    MedlinePlus

    ... ncbi.nlm.nih.gov/pubmed/23265327 . Swerdlow CD, Wang PJ, Zipes DP. Pacemakers and implantable cardioverter-defibrillators. ... and lifestyle Controlling your high blood pressure Dietary fats explained Fast food tips Heart attack - discharge Heart ...

  9. Interference of programmed electromagnetic stimulation with pacemakers and automatic implantable cardioverter defibrillators.

    PubMed

    Gwechenberger, Marianne; Rauscha, Friedrich; Stix, Günter; Schmid, Gernot; Strametz-Juranek, Jeanette

    2006-07-01

    A commercially available magnetic therapy system, designed for clinical application as well as for private use without medical supervision, was examined with respect to its potential for causing electromagnetic interference with implantable pacemakers (PMs) and automatic implantable cardioverter defibrillators (AICDs). A sample of 15 PMs and 5 AICDs were experimentally investigated. Each of the implants was realistically positioned in a homogeneous, electrically passive torso phantom and exposed to the magnetic fields of the system's applicators (whole body mat, cushion, and bar applicator). The detection thresholds of the implants were programmed to maximum sensitivity and both unipolar as well as bipolar electrode configurations were considered. The evaluation of possible interferences was derived from the internal event storages and pacing statistics recorded by the implants during exposure. Any "heart activity" recorded by the implants during exposure was interpreted as a potential interference, because the implant obviously misinterpreted the external interference signal as a physiological signal. Only cases without any recorded "heart activity" and with nominal pacing rates (as expected from the program parameter settings) of the implants were rated as "interference-free." Exposure to the whole body mat (peak magnetic induction up to 265 microT) did not show an influence on PMs and AICD in any case. The cushion applicator at the highest field intensity (peak magnetic induction up to 360 microT) led to atrial sensing defects in four PM models with unipolar electrode configuration. Under bipolar electrode configuration no disturbances occurred. The bar applicator led to sensing problems and consecutively reduced pacing rates in all tested PM models under unipolar electrode configuration and maximum field intensity (peak magnetic induction up to 980 microT). Bipolar electrode configuration resolved the problem. The investigated AICDs did not show malfunctions

  10. Obstetric hemorrhage in a case of hypertrophic obstructive cardiomyopathy with automatic implantable cardioverter defibrillator: Anaesthesia and intensive care management.

    PubMed

    Mishra, Sandeep Kumar; Bhat, Ravindra R; Kavitha, Jayaram; Kundra, Pankaj; Parida, Satyen

    2016-01-01

    The physiological changes occurring during pregnancy and labor may reveal or exacerbate the symptoms of hypertrophic obstructive cardiomyopathy (HOCM). The addition of obstetric hemorrhage to this presents a unique challenge to the anesthesiologists and intensivists managing these patients in the operation theatres and the Intensive Care Units. Here we present a case of HOCM with automatic implantable cardioverter defibrillator in situ and postpartum hemorrhagic shock.

  11. [The clinical practice guidelines of the Sociedad Española de Cardiología on the automatic implantable defibrillator].

    PubMed

    Pérez-Villacastín, J; Carmona Salinas, J R; Hernández Madrid, A; Marín Huerta, E; Merino Llorens, J L; Ormaetxe Merodio, J; Moya i Mitjans, A

    1999-12-01

    Since the first implantation in man in 1980 implantable cardioverter defibrillator technology has greatly improved and the number of devices implanted has increased considerably every year. Non thoracotomy lead systems and biphasic shocks are now the approach of choice, offering an almost 100% success rate. This document reviews the recommendations for qualification of personnel and for the centres implanting and carrying out follow-ups on defibrillators. The current indications for the implantation of implantable cardioverter defibrillator are also addressed.

  12. Automatic implantable cardiac defibrillator implantation may precipitate effort-induced thrombosis in young athletes: a case report and literature review.

    PubMed

    Wadhawan, Abhishek; Laage Gaupp, Fabian M; Sista, Akhilesh K

    2014-01-01

    Upper extremity deep vein thrombosis (DVT) is a common finding after implantation of an automatic implantable cardiac defrillator (AICD). We describe the case of a patient who developed a left upper extremity DVT 4.5 months after implantation of an AICD and was found to have a lead-induced stenosis with possible underlying Paget-Schroetter syndrome (PSS) in the midbrachiocephalic vein on venography. While his symptoms resolved after the combination of pharmacomechanical thrombolysis, angioplasty, and anticoagulation, his long-term management is complicated by the presence of both PSS and lead-induced stenosis. Herein, we discuss his presentation, treatment, and future management options.

  13. How Does an Implantable Cardioverter Defibrillator Work?

    MedlinePlus

    ... Defibrillator Work? An implantable cardioverter defibrillator (ICD) has wires with electrodes on the ends that connect to one or more of your heart's chambers. These wires carry the electrical signals from your heart to ...

  14. Intraoperative defibrillation threshold testing and postoperative long-term efficacy of cardioverter-defibrillator implantation

    PubMed Central

    GAN, TIANYI; CAO, XIAOZHI; YU, ZHANG; TANG, BAOPENG; LI, JINXIN; XU, GUOJUN; ZHOU, XIANHUI; ZHANG, YANYI; LI, YAODONG; ZHANG, JIANGHUA

    2013-01-01

    The aim of this study was to determine the defibrillation threshold (DFT) of implantable cardioverter-defibrillators (ICDs) and outcomes of treatment. Sixty-four patients received cardioverter-defibrillator implantation. During implantation, the DFT was determined by the defibrillation safety margin (DSM). All patients were followed up for 12–48 months after the implantation. The overall DFT was 14.27±2.56 J and the DSM was 18.40±1.89 J. Malignant ventricular arrhythmias occurred in 42 patients following cardioverter-defibrillator implantation including 500 episodes of non-sustained ventricular tachycardia (VT) and 289 episodes of persistent VT. VT was treated using antitachycardia pacing (ATP); 265 episodes were treated successfully by a single ATP treatment (91.69%) and 12 episodes were treated successfully by two ATP treatments (4.15%). Twelve episodes were converted by low-energy electrical cardioversion (4.15%). A total of 175 ventricular fibrillation (VF) episodes were identified, of which 18 episodes automatically terminated prior to treatment. In total, 146 episodes were converted by a single cardioversion with a defibrillation energy of 13.21±2.58 J and 11 episodes were converted by two cardioversions with a defibrillation energy of 16.19±2.48 J. It is safe and feasible to determine the DFT by DSM measurement during cardioverterdefibrillator implantation. PMID:23251292

  15. [Atrial defibrillators or implantable atrioverters. Initial results].

    PubMed

    Lévy, S; Taramasco, V; Corbelli, J L; Mistretta, R; Dolla, E; Ricard, P

    1998-07-01

    The atrial defibrillator is a new non-pharmacological treatment of atrial fibrillation (AF) for restoration of sinus rhythm. This device has two programmable modes: automatic or activated by the physician or patient. In the automatic mode, the device delivers a shock synchronous with the R wave to restore sinus rhythm when AF is detected. Two patients with paroxysmal AF resistant to pharmacological therapy were included in a study to assess the efficacy and safety of the atrial defibrillator in the mode activated by the physician. The device implanted in the pectoral region is connected to 3 electrodes, two for atrial defibrillation and sensing positioned in the coronary sinus and right atrium respectively and a sensing and pacing electrode in the right ventricle. The right ventricle is paced if a post-shock pause is detected. It is possible to interrogate the device with a programmer using its Holter function and so determine the number of episodes of AF sensed and treated. The number, intensity and energy of the shocks and the parameters of ventricular stimulation are programmable. In these two patients, the atrial defibrillator effectively reduced prolonged episodes of AF with a follow-up of 12 and 7 months. No pro-arrhythmic effects were observed. Further clinical evaluation is under way to assess this new mode of treatment, including the mode activated by the patient, safety and tolerance of the shocks. In our two patients, the treatment of prolonged episodes of AF was followed by reduction of many short or asymptomatic episodes.

  16. Optimal Implantable Cardioverter Defibrillator Programming.

    PubMed

    Shah, Bindi K

    Optimal programming of implantable cardioverter defibrillators (ICDs) is essential to appropriately treat ventricular tachyarrhythmias and to avoid unnecessary and inappropriate shocks. There have been a series of large clinical trials evaluating tailored programming of ICDs. We reviewed the clinical trials evaluating ICD therapies and detection, and the consensus statement on ICD programming. In doing so, we found that prolonged ICD detection times, higher rate cutoffs, and antitachycardia pacing (ATP) programming decreases inappropriate and painful therapies in a primary prevention population. The use of supraventricular tachyarrhythmia discriminators can also decrease inappropriate shocks. Tailored ICD programming using the knowledge gained from recent ICD trials can decrease inappropriate and unnecessary ICD therapies and decrease mortality.

  17. Optimal Implantable Cardioverter Defibrillator Programming.

    PubMed

    Shah, Bindi K

    2016-11-17

    Optimal programming of implantable cardioverter defibrillators (ICDs) is essential to appropriately treat ventricular tachyarrhythmias and to avoid unnecessary and inappropriate shocks. There have been a series of large clinical trials evaluating tailored programming of ICDs. We reviewed the clinical trials evaluating ICD therapies and detection, as well as the consensus statement on ICD programming. In so doing, we found that prolonged ICD detection times, higher rate cutoffs, and antitachycardia pacing programming decreases inappropriate and painful therapies in a primary prevention population. The use of supraventricular tachyarrhythmia discriminators can also decrease inappropriate shocks. Tailored ICD programming using the knowledge gained from recent ICD trials can decrease inappropriate and unnecessary ICD therapies, and decrease mortality.

  18. Implantation of additional defibrillation lead into the coronary sinus: an effective method of decreasing defibrillation threshold.

    PubMed

    Wilczek, Rajmund; Swiątkowski, Maciej; Czepiel, Aleksandra; Sterliński, Maciej; Makowska, Ewa; Kułakowski, Piotr

    2011-01-01

    We report a case of successful implantation of an additional defibrillation lead into the coronary sinus due to high defibrillation threshold (DFT) in a seriously ill patient with a history of extensive myocardial infarction referred for implantable cardioverter- defibrillator implantation after an episode of unstable ventricular tachycardia. All previous attempts to reduce DFT, including subcutaneous electrode implantation, had been unsuccessful.

  19. Pacemakers and Implantable Defibrillators: MedlinePlus Health Topic

    MedlinePlus

    ... Association) How Does a Pacemaker Work? (National Heart, Lung, and Blood Institute) How Does an Implantable Cardioverter Defibrillator Work? (National Heart, Lung, and Blood Institute) Implantable Cardioverter Defibrillator (National Heart, Lung, and ...

  20. Athletes with Implantable Cardioverter Defibrillators

    PubMed Central

    Ponamgi, Shiva P.; DeSimone, Christopher V.; Ackerman, Michael J.

    2015-01-01

    Summary Athletes with an implantable cardioverter defibrillator (ICD) represent a diverse group of individuals who may be at an increased risk of sudden cardiac death (SCD) when engaging in vigorous physical activity. Therefore, they are excluded by the current guidelines from participating in most competitive sports except those classified as low intensity, such as bowling and golf. The lack of substantial data on the natural history of the cardiac diseases affecting these athletes, as well as the unknown efficacy of implanted ICDs in terminating life-threatening arrhythmias occurring during intense exercise, have resulted in the restrictive nature of these now decade old guidelines. Recently, there is emerging data, derived from a few retrospective studies and a large prospective registry that demonstrates the relative safety of high-risk athletes participating in competitive sports and challenges the prohibitive nature of these guidelines. Nevertheless, the safe participation of all athletes with an ICD in competitive sports continues to be contemplated. The increased number of inappropriate shocks, damage to the ICD/pacemaker system, and the questionable efficacy of the delivered shock in the setting of vigorous physical activity are some of the main challenges faced by these athletes who choose to continue participation in competitive sports. The fear of SCD and ICD shocks faced by these athletes is also associated with a negative psychological burden and affects their quality of life, as does restricting them from all competitive sports. Therefore, shared decision making is necessary between the clinician and athlete after carefully analyzing the risks and benefits associated with competitive sports participation. PMID:26100423

  1. [Research on automatic external defibrillator based on DSP].

    PubMed

    Jing, Jun; Ding, Jingyan; Zhang, Wei; Hong, Wenxue

    2012-10-01

    Electrical defibrillation is the most effective way to treat the ventricular tachycardia (VT) and ventricular fibrillation (VF). An automatic external defibrillator based on DSP is introduced in this paper. The whole design consists of the signal collection module, the microprocessor controlingl module, the display module, the defibrillation module and the automatic recognition algorithm for VF and non VF, etc. This automatic external defibrillator has achieved goals such as ECG signal real-time acquisition, ECG wave synchronous display, data delivering to U disk and automatic defibrillate when shockable rhythm appears, etc.

  2. Subcutaneous Implantable Cardioverter-Defibrillator

    MedlinePlus

    ... Circulation . 2013 ; 128 : 944 – 953 . OpenUrl Abstract / FREE Full Text 2. ↵ Lambiase PD , Theuns DAMJ , Barr C , Knopps ... defibrillator. Circulation . 2013 ; 128 : 938 – 940 . OpenUrl FREE Full Text View Abstract Back to top Previous Article Next ...

  3. Shocks from Implanted Defibrillators Trigger Health Costs of Their Own

    MedlinePlus

    ... Reynolds. "Improving the reliability of implantable defibrillators, and programming them in a manner that minimizes shock events, ... efforts are needed to ensure optimization of ICD programming, along with other strategies to reduce ICD shocks," ...

  4. Many People with Implantable Defibrillators Can Participate in Vigorous Sports

    MedlinePlus

    ... people with implantable defibrillators can participate in vigorous sports May 20, 2013 Categories: Heart News Study Highlights : ... may safely participate in a number of vigorous sports. The study challenges some current science recommendations advising ...

  5. Automatic and Semiautomatic External Defibrillator/Pacers: Futuristic Emergency Devices

    PubMed Central

    Fast, Thomas B.; Cavallaro, Daniel L.

    1987-01-01

    Automatic and semiautomatic defibrillator/pacers are new devices that combine many of the functions of an ECG unit, an external pacemaker, and a defibrillator into one unit with a built-in logic system. These devices are well researched and are gaining acceptance by the American Heart Association, emergency room physicians, and others concerned with emergency treatment of cardiac arrest, fibrillation, and potentially fatal dysrhythmias. These instruments are dependable, easy to use, and may in the future have a potential value for some dental practitioners who treat high risk cardiac patients or those using deep sedation and general anesthesia. ImagesFIG. 1FIG. 2FIG. 3 PMID:2955722

  6. Bilateral Subclavian Vein Occlusion in a SAPHO Syndrome Patient Who Needed an Implantable Cardioverter Defibrillator.

    PubMed

    Ishizuka, Masato; Yamamoto, Yuko; Yamada, Shintaro; Maemura, Sonoko; Nakata, Ryo; Motozawa, Yoshihiro; Yamamoto, Keisuke; Takizawa, Masataka; Uozumi, Hiroki; Ikenouchi, Hiroshi

    2016-05-25

    A 79-year-old Asian man was hospitalized because of progressive exertional dyspnea with decreasing left ventricular ejection fraction and frequent non-sustained ventricular tachycardia. Pre-procedure venography for implantable cardioverter defibrillator (ICD) implantation showed occlusion of the bilateral subclavian veins. In consideration of subcutaneous humps in the sterno-clavicular area and palmoplantar pustulosis, we diagnosed him as having synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome and speculated that it induced peri-osteal chronic inflammation in the sterno-clavicular area, resulting in occlusion of the adjacent bilateral subclavian veins. An automatic external defibrillator (AED) was installed in the patient's house and total subcutaneous ICD was considered. Venous thrombosis in SAPHO syndrome is not frequent but has been reported. To the best of our knowledge, this is the first case of bilateral subclavian vein occlusion in a SAPHO syndrome patient who needs ICD implantation.

  7. Shock whilst gardening--implantable defibrillators & lawn mowers.

    PubMed

    Von Olshausen, G; Lennerz, C; Grebmer, C; Pavaci, H; Kolb, C

    2014-02-01

    Electromagnetic interference with implantable cardioverter defibrillators (ICDs) can cause inappropriate shock delivery or temporary inhibition of ICD functions. We present a case of electromagnetic interference between a lawn mower and an ICD resulting in an inappropriate discharge of the device due to erroneous detection of ventricular fibrillation.

  8. Successful intermuscular implantation of subcutaneous implantable cardioverter defibrillator in a Japanese patient with pectus excavatum.

    PubMed

    Kondo, Yusuke; Ueda, Marehiko; Winter, Joachim; Nakano, Miyo; Nakano, Masahiro; Ishimura, Masayuki; Miyazawa, Kazuo; Tateno, Kaoru; Kobayashi, Yoshio

    2017-02-01

    The entirely subcutaneous implantable cardioverter-defibrillator (ICD) system was developed to provide a life-saving defibrillation therapy that does not affect the heart and vasculature. The subcutaneous ICD is preferred over the transvenous ICD for patients with a history of recurrent infection presenting major life-threatening rhythms. In this case report, we describe the first successful intermuscular implantation of a completely subcutaneous ICD in a Japanese patient with pectus excavatum. There were no associated complications with the device implantation or lead positioning. Further, the defibrillation threshold testing did not pose any problem with the abnormal anatomy of the patient.

  9. [Cardiac Pacemakers, implantable defibrillators and IRM].

    PubMed

    Frank, R; Hidden-Lucet, F; Himbert, C; Petitot, J C; Fontaine, G

    2003-04-01

    The IRM is formally contraindicated to the pacemaker and cardiac defibrillator wearers because of the risk of inhibition or inappropriate stimulations during the examination. However if the examination is essential, suitable programming of the apparatus and a constant monitoring of the heartbeat rate by a qualified doctor in cardiac stimulation must make it possible to avoid any accident.

  10. Beyond the implantable cardioverter-defibrillator: are we making progress?

    PubMed

    Weiss, James N

    2008-06-01

    Sudden cardiac death due to ventricular fibrillation occurs when a dynamic interaction between triggers and substrate leads to the development of reentry, initiation of ventricular tachycardia, and its degeneration to fibrillation. To move beyond the implantable cardioverter-defibrillator as the only effective therapy for aborting sudden cardiac death, an improved understanding of trigger-substrate interaction is essential. This brief review summarizes some of the recent progress in this direction.

  11. Lingular pneumonia obscured by implanted cardioverter-defibrillator: Lateral thinking.

    PubMed

    Sewell, Laura; Harries, Ivan; Chandrasekaran, Barinathan

    2015-01-01

    A 56-year-old female with an implanted cardioverter-defibrillator was admitted with a short history suggestive of a diagnosis of pneumonia. An AP radiograph did not identify an area of consolidation. A subsequent lateral radiograph highlighted an extensive left-lingular-lobe consolidation that had been obscured by the cardiac device. This case highlights the fact that large devices can obscure significant pathology, and that lateral or cross-sectional imaging may be helpful in reaching a diagnosis.

  12. Spinal cord stimulation for refractory angina in a patient implanted with a cardioverter defibrillator.

    PubMed

    Ferrero, Paolo; Grimaldi, Roberto; Massa, Riccardo; Chiribiri, Amedeo; De Luca, Anna; Castellano, Maddalena; Cardano, Paola; Trevi, Gian Paolo

    2007-01-01

    Spinal cord stimulation is currently used to treat refractory angina. Some concerns may arise about the possible interaction concerning the spinal cord stimulator in patients already implanted with a pacemaker or a cardioverter defibrillator. We are going to describe the successful implantation of a spinal cord stimulator in a patient previously implanted with a cardioverter defibrillator.

  13. Epicardial implantable cardioverter-defibrillator system placed in a 4.9-kg infant.

    PubMed

    Bryant, Roosevelt; Aboutalebi, Amir; Kim, Jeffrey J; Kertesz, Naomi; Morales, David L S

    2011-01-01

    Implantable cardioverter-defibrillators have aided the prevention of sudden cardiac death in adults. The hope is to provide similar benefits to the pediatric population as the devices become smaller. Herein, we present the case of a 4.9-kg, 5-week-old infant boy who presented with cardiopulmonary arrest. After emergency defibrillation, conventional treatment options included long-term hospitalization for later cardioverter-defibrillator implantation, or installation of an external defibrillator with subsequent home telemetry. On the basis of the infant's body dimensions, we decided that an epicardial implantable cardioverter-defibrillator was feasible and the best option. We performed a median sternotomy and placed a Vitality® implantable cardioverter-defibrillator with a 25-cm defibrillator coil and a 35-cm bipolar ventricular lead. The patient experienced no postoperative morbidity or rhythm disturbances and was discharged from the hospital on postoperative day 5. He was placed on β-blocker therapy and has remained well for 3 years.Although external devices can be placed in a small patient, we believe that they are too susceptible to lead damage and lead migration, and that the defibrillator thresholds are less reliable. We think that dysrhythmias even in very small children can be treated effectively and safely with use of an epicardial implantable cardioverter-defibrillator. To our knowledge, this 4.9-kg infant is the smallest patient to have undergone a successful implantation of this kind.

  14. Patient perceptions of implantable cardioverter-defibrillator deactivation discussions: A qualitative study

    PubMed Central

    MacIver, Jane; Tibbles, Alana; Billia, Filio; Ross, Heather

    2016-01-01

    Background: There is a class I recommendation for implantable cardioverter-defibrillator deactivation discussions to occur between physicians and heart failure patients. Few studies have reported the patient’s perspective on the timing of implantable cardioverter-defibrillator deactivation discussions. Aim: To determine patient awareness, preferences and timing of implantable cardioverter-defibrillator deactivation discussions. Design: Grounded theory was used to collect and analyze interview data from 25 heart failure patients with an implantable cardioverter-defibrillator. Setting and participants: Patients with an implantable cardioverter-defibrillator, from the Heart Function Clinic at University Health Network (Toronto, Canada). Results: The sample (n = 25) was predominately male (76%) with an average age of 62 years. Patients identified three stages where they felt implantable cardioverter-defibrillator deactivation should be discussed: (1) prior to implantation, (2) with any significant deterioration but while they were of sound mind to engage in and communicate their preferences and (3) at end of life, where patients wished further review of their previously established preferences and decisions about implantable cardioverter-defibrillator deactivation. Most patients (n = 17, 68%) said they would consider deactivation, six (24%) were undecided and two (8%) were adamant they would never turn it off. Conclusion: The patient preferences identified in this study support the need to include information on implantable cardioverter-defibrillator deactivation at implant, with change in clinical status and within broader discussions about end-of-life treatment preferences. Using this process to help patients determine and communicate their implantable cardioverter-defibrillator deactivation preferences may reduce the number of patients experiencing distressing implantable cardioverter-defibrillator shocks at end of life. PMID:27110361

  15. Sports participation in patients with implantable cardioverter-defibrillators.

    PubMed

    Lampert, R; Olshansky, B

    2012-06-01

    The safety of sports participation for patients with implantable cardioverter-defibrillators (ICDs) is not yet defined, and current recommendations in both Europe and the US restrict these patients from competative sports more vigorous than golf or bowling. Postulated risks include increased frequency of arrhythmias, inability of the ICD to terminate ventricular arrhythmias during the metabolic changes accompanying extreme exercise, injury to the patient, or damage to the ICD system. However, survey data suggest that many ICD patients do participate in sports, and risks may be fewer than postulated. Ongoing research will better delineate the risks of sports for patients with ICDs.

  16. Magnets and implantable cardioverter defibrillators: what's the problem?

    PubMed

    Rodriguez-Blanco, Yiliam F; Souki, Fouad; Tamayo, Evelyn; Candiotti, Keith

    2013-01-01

    A growing number of surgical patients present to the operating room with implantable cardioverter defibrillators (ICD). Peri-operative care of these patients dictates that ICD function be suspended for many surgical procedures to avoid inappropriate, and possibly harmful, ICD therapy triggered by electromagnetic interference (EMI). An alternative to reprogramming the ICD is the use of a magnet to temporarily suspend its function. However, this approach is not without complications. We report a case where magnet use failed to inhibit ICD sensing of EMI, and a shock was delivered to the patient. Measures to decrease EMI, controversies regarding magnet use, and expert recommendations are discussed.

  17. Predictors of implantable cardioverter defibrillator shocks during the first year.

    PubMed

    Dougherty, Cynthia M; Hunziker, Jim

    2009-01-01

    The purpose of this study was to predict implantable cardioverter defibrillator (ICD) shocks using demographic and clinical characteristics in the first year after implantation for secondary prevention of cardiac arrest. A prospective design was used to follow 168 first-time ICD recipients over 12 months. Demographic and clinical data were obtained from medical records at the time of ICD insertion. Implantable cardioverter defibrillator shock data were obtained from ICD interrogation reports at hospital discharge, 3, 6, and 12 months. Logistic regression was used to predict ever receiving an ICD shock using background characteristics. Patients received an ICD for secondary prevention of sudden cardiac arrest, they were 64.1 years old, 89% were white, 77% were male, with a mean (SD) ejection fraction of 33.7% (14.1%). The cumulative percentage of ever receiving an ICD shock was 33.3% over 1 year. Three variables predicted shocks in the first year: history of chronic obstructive pulmonary disease (COPD) (odds ratio [OR], 4.42; 95% confidence interval [CI], 1.2-16.4; P = .03), history of congestive heart failure (OR, 3.55; 95% CI, 1.4-9.3; P = .01), and documented ventricular tachycardia (VT) at the time of ICD implant (OR, 10.05; 95% Cl, 1.8-55.4; P = .01). High levels of anxiety approached significance (OR = 2.82; P = .09). The presence of COPD, congestive heart failure, or VT at ICD implant was a significant predictor of receiving an ICD shock in the first year after ICD implantation. Because ICD shocks are distressing, painful, and associated with greater mortality, healthcare providers should focus attention on prevention of shocks by controlling VT, careful management of HF symptoms, reduction of the use of short acting beta agonist medications in COPD, and perhaps recognizing and treating high levels of anxiety.

  18. Critical analysis of ineffective post implantation implantable cardioverter-defibrillator-testing

    PubMed Central

    Roos, Markus; Geller, J Christoph; Ohlow, Marc-Alexander

    2017-01-01

    AIM To test of the implantable-cardioverter-defibrillator is done at the time of implantation. We investigate if any testing should be performed. METHODS All consecutive patients between January 2006 and December 2008 undergoing implantable cardioverter-defibrillator (ICD) implantation/replacement (a total of 634 patients) were included in the retrospective study. RESULTS Sixteen patients (2.5%) were not tested (9 with LA/LV-thrombus, 7 due to operator’s decision). Analyzed were 618 patients [76% men, 66.4 + 11 years, 24% secondary prevention (SP), 46% with left ventricular ejection fraction (LVEF) < 20%, 56% had coronary artery disease (CAD)] undergoing defibrillation safety testing (SMT) with an energy of 21 + 2.3 J. In 22/618 patients (3.6%) induced ventricular fibrillation (VF) could not be terminated with maximum energy of the ICD. Six of those (27%) had successful SMT after system modification or shock lead repositioning, 14 patients (64%) received a subcutaneous electrode array. Younger age (P = 0.0003), non-CAD (P = 0.007) and VF as index event for SP (P = 0.05) were associated with a higher incidence of ineffective SMT. LVEF < 20% and incomplete revascularisation in patients with CAD had no impact on SMT. CONCLUSION Defibrillation testing is well-tolerated. An ineffective SMT occurred in 4% and two third of those needed implantation of a subcutaneous electrode array to pass a SMT > 10 J. PMID:28289531

  19. The federal audit of implantable cardioverter-defibrillator implants: lessons learned.

    PubMed

    Steinberg, Jonathan S; Mittal, Suneet

    2012-04-03

    The federal government has investigated a large number of institutions regarding concerns that implantable cardioverter-defibrillator procedures were performed in violation of the criteria set forth in a National Coverage Determination. We describe our experience and responses to such an audit, as well as the to complexities and nuances of practicing evidence-based medicine in the setting of heavy regulatory oversight.

  20. Deactivation of Pacemakers and Implantable Cardioverter-Defibrillators

    PubMed Central

    Kramer, Daniel B.; Mitchell, Susan L.; Brock, Dan W.

    2013-01-01

    Cardiac implantable electrical devices (CIEDs), including pacemakers (PMs) and implantable cardioverter-defibrillators (ICDs), are the most effective treatment for life-threatening arrhythmias. Patients or their surrogates may request device deactivation to avoid prolongation of the dying process or in other settings, such as after device-related complications or with changes in their health care goals. Despite published guidelines outlining theoretical and practical aspects of this common clinical scenario, significant uncertainty remains for both patients and health care providers regarding the ethical and legal status of CIED deactivation. This review outlines the ethical and legal principles supporting CIED deactivation at patients’ request, centered upon patient autonomy and authority over their own medical treatment. The empirical literature describing stakeholder views and experiences surrounding CIED deactivation is described, along with lessons for future research and practice guidance surrounding the care of patients with CIEDs. PMID:23217433

  1. Cost effectiveness of the implantable cardioverter defibrillator: a preliminary analysis

    PubMed Central

    O'Brien, Bernie J; Buxton, Martin J; Rushby, Julia A

    1992-01-01

    Background—An implantable cardioverter defibrillator (ICD) may be effective in reducing the risk of sudden cardiac death. The high cost of ICD treatment, however, compared with alternatives raises the question of whether this new technology is an efficient use of scarce health care resources. Objective—To estimate the incremental cost effectiveness of the implantable cardioverter defibrillator compared with drug treatment with amiodarone in the management of patients at high risk of sudden cardiac death. Design—A cost effectiveness model was constructed from data already published and other secondary sources. Differences in patient survival were calculated from life tables for comparable ICD and amiodarone patient series. Costs were based on typical patient management protocols derived from current United Kingdom practice and interviews with physicians. Main outcome measures—Cost effectiveness of ICD treatment was computed over 20 years; all future costs and effects were discounted at 6% per year. Results—Estimated life expectancy was 11·1 and 6·7 years with ICD and amiodarone respectively; the discounted 20 year difference lies in the range 1·7 to 3·7 years. Discounted 20 year treatment costs were £28 400 for the ICD and £2300 for amiodarone. Cost effectiveness of ICD treatment lies in the range of £15 400 to £8200 per life-year gained. Conclusions—Cost effectiveness of ICD treatment is similar to some existing cardiac programmes funded under the NHS but uncertainty exists due to limitations of the data. Costs of ICD treatment may fall in the future as the life of the device increases and less invasive implantation methods are needed. The effectivess of ICD compared with amiodarone is currently being studied by a randomised controlled trial. PMID:1389748

  2. Economic evaluations of implantable cardioverter defibrillators: a systematic review.

    PubMed

    García-Pérez, Lidia; Pinilla-Domínguez, Pilar; García-Quintana, Antonio; Caballero-Dorta, Eduardo; García-García, F Javier; Linertová, Renata; Imaz-Iglesia, Iñaki

    2015-11-01

    The aim of this paper was to review the cost-effectiveness studies of implantable cardioverter defibrillators (ICD) for primary or secondary prevention of sudden cardiac death (SCD). A systematic review of the literature published in English or Spanish was performed by electronically searching MEDLINE and MEDLINE in process, EMBASE, NHS-EED, and EconLit. Some keywords were implantable cardioverter defibrillator, heart failure, heart arrest, myocardial infarction, arrhythmias, syncope, sudden death. Selection criteria were the following: (1) full economic evaluations published after 1995, model-based studies or alongside clinical trials (2) that explored the cost-effectiveness of ICD with or without associated treatment compared with placebo or best medical treatment, (3) in adult patients for primary or secondary prevention of SCD because of ventricular arrhythmias. Studies that fulfilled these criteria were reviewed and data were extracted by two reviewers. The methodological quality of the studies was assessed and a narrative synthesis was prepared. In total, 24 studies were included: seven studies on secondary prevention and 18 studies on primary prevention. Seven studies were performed in Europe. For secondary prevention, the results showed that the ICD is considered cost-effective in patients with more risk. For primary prevention, the cost-effectiveness of ICD has been widely studied, but uncertainty about its cost-effectiveness remains. The cost-effectiveness ratios vary between studies depending on the patient characteristics, methodology, perspective, and national settings. Among the European studies, the conclusions are varied, where the ICD is considered cost-effective or not dependent on the study.

  3. Beam Profile Disturbances from Implantable Pacemakers or Implantable Cardioverter-Defibrillator Interactions

    SciTech Connect

    Gossman, Michael S.; Nagra, Bipinpreet; Graves-Calhoun, Alison; Wilkinson, Jeffrey

    2011-01-01

    The medical community is advocating for progressive improvement in the design of implantable cardioverter-defibrillators and implantable pacemakers to accommodate elevations in dose limitation criteria. With advancement already made for magnetic resonance imaging compatibility in some, a greater need is present to inform the radiation oncologist and medical physicist regarding treatment planning beam profile changes when such devices are in the field of a therapeutic radiation beam. Treatment plan modeling was conducted to simulate effects induced by Medtronic, Inc.-manufactured devices on therapeutic radiation beams. As a continuation of grant-supported research, we show that radial and transverse open beam profiles of a medical accelerator were altered when compared with profiles resulting when implantable pacemakers and cardioverter-defibrillators are placed directly in the beam. Results are markedly different between the 2 devices in the axial plane and the sagittal planes. Vast differences are also presented for the therapeutic beams at 6-MV and 18-MV x-ray energies. Maximum changes in percentage depth dose are observed for the implantable cardioverter-defibrillator as 9.3% at 6 MV and 10.1% at 18 MV, with worst distance to agreement of isodose lines at 2.3 cm and 1.3 cm, respectively. For the implantable pacemaker, the maximum changes in percentage depth dose were observed as 10.7% at 6 MV and 6.9% at 18 MV, with worst distance to agreement of isodose lines at 2.5 cm and 1.9 cm, respectively. No differences were discernible for the defibrillation leads and the pacing lead.

  4. The Challenges of Living With an Implantable Cardioverter Defibrillator: A Qualitative Study

    PubMed Central

    Abbasi, Mohammad; Negarandeh, Reza; Norouzadeh, Reza; Shojae Mogadam, Amir Reza

    2016-01-01

    Background Dysrhythmia is one of the most common causes of sudden cardiac death worldwide. An implantable cardioverter defibrillator is the most effective method of treatment for dysrhythmias causing cardiac arrest. However, living with an implantable cardioverter defibrillator is associated with challenges such as fear, anxiety, and depression. Objectives The purpose of this study was to identify the challenges of living with an implantable cardioverter defibrillator. Patients and Methods In this qualitative study, an interpretive phenomenological approach was used, with thirteen participants (seven men and six women) between the ages of 21 and 70 years old (mean = 58.15, SD = 14.4). The duration of having an implantable cardioverter defibrillator was 1 - 120 months (mean = 23.15, SD = 33.31). Maximum variation sampling was used to purposefully select the participants from the governmental Imam Khomeini hospital in Tehran, Iran, between May and October of 2013. Semi-structured interviews were conducted for 30 to 45 minutes, and Van Manen’s six-step method was used in this study. Results The challenges of living with an implantable cardioverter defibrillator include: living with fear, concerns about the future, concerns about device malfunction, fearing death during the shock, pain due to the shock, loss of control, the cost of the device, and the lifestyle limitations. Conclusions Patients who live with implantable cardioverter defibrillators face many concerns and challenges. Therefore, the role of nurses in teaching patients before and after implementation is very important. PMID:28180011

  5. [Implantable Cardioverter Defibrillator and Perioperative Magnet Application: A Case Report].

    PubMed

    Inoue, Miho; Tokuhira, Natsuko; Sawa, Teiji; Ibuki, Takae

    2015-02-01

    An implantable cardioverter defibrillator (ICD) can falsely recognize noise by monopolar electrocautery as tachyarrhythmia and deliver inappropriate antitachycardia therapy. Application of a clinical magnet on an ICD suspends antitachycardia therapy, but it has not been widely used for this purpose. A 67-year-old male underwent laryngopharyngectomy, cervical esophagectomy, right neck dissection, tracheostomy and reconstruction with free jejunal transplant for recurrent hypopharyngeal cancer. He had an ICD (PARADYM DR8550, Sorin) implanted below the left clavicle for ventricular tachycardia and prolonged QT syndrome. During the operation, a clinical magnet was left on the ICD to disable antitachycardia therapy. The magnet mode of the ICD provided asynchronous AAI pacing at 96 beats x min(-1). The surgery proceeded uneventfully. No episode of ventricular tachyarrythmia or pacing inhibition by electromagnetic interference was observed on electrocardiogram. This case illustrated the potential role of a clinical magnet as an alternative to reprogramming of an ICD by a programmer in the perioperative management of a patient with an ICD when a technical expert to operate a programmer is not available.

  6. Ambient temperature and activation of implantable cardioverter defibrillators

    NASA Astrophysics Data System (ADS)

    McGuinn, L.; Hajat, S.; Wilkinson, P.; Armstrong, B.; Anderson, H. R.; Monk, V.; Harrison, R.

    2013-09-01

    The degree to which weather influences the occurrence of serious cardiac arrhythmias is not fully understood. To investigate, we studied the timing of activation of implanted cardiac defibrillators (ICDs) in relation to daily outdoor temperatures using a fixed stratum case-crossover approach. All patients attending ICD clinics in London between 1995 and 2003 were recruited onto the study. Temperature exposure for each ICD patient was determined by linking each patient's postcode of residence to their nearest temperature monitoring station in London and the South of England. There were 5,038 activations during the study period. Graphical inspection of ICD activation against temperature suggested increased risk at lower but not higher temperatures. For every 1 °C decrease in ambient temperature, risk of ventricular arrhythmias up to 7 days later increased by 1.2 % (95 % CI -0.6 %, 2.9 %). In threshold models, risk of ventricular arrhythmias increased by 11.2 % (0.5 %, 23.1 %) for every 1° decrease in temperature below 2 °C. Patients over the age of 65 exhibited the highest risk. This large study suggests an inverse relationship between ambient outdoor temperature and risk of ventricular arrhythmias. The highest risk was found for patients over the age of 65. This provides evidence about a mechanism for some cases of low-temperature cardiac death, and suggests a possible strategy for reducing risk among selected cardiac patients by encouraging behaviour modification to minimise cold exposure.

  7. Mycobacterium fortuitum causing infection of a biventricular pacemaker/implantable cardioverter defibrillator.

    PubMed

    Hu, Yuhning L; Bridge, Bronwyn; Wang, Jeffrey; Jovin, Ion S

    2012-12-01

    Increased utilization of cardiovascular implantable electronic devices (CIED) has seen a corresponding rise in related infections. Non-tuberculosis mycobacteria (NTM) are rarely the cause. Treatment involves susceptibilities, antimicrobials, and device removal. This study presents a patient who underwent a biventricular implantable cardioverter defibrillator upgrade with a multi-drug resistant Mycobacterium fortuitum located at the pocket site and a lead infection.

  8. Initial experience of subcutaneous implantable cardioverter defibrillators in Singapore: a case series and review of the literature.

    PubMed

    Lim, Tien Siang Eric; Tan, Boon Yew; Ho, Kah Leng; Lim, Chuh Yih Paul; Teo, Wee Siong; Ching, Chi-Keong

    2015-10-01

    Transvenous implantable cardioverter defibrillators are a type of implantable cardiac device. They are effective at reducing total and arrhythmic mortality in patients at risk of sudden cardiac death. Subcutaneous implantable cardioverter defibrillators (S-ICDs) are a new alternative that avoids the disadvantages of transvenous lead placement. In this case series, we report on the initial feasibility and safety of S-ICD implantation in Singapore.

  9. Use of the automatic external defibrillator-pacemaker by ambulance personnel: the Stockport experience.

    PubMed Central

    Gray, A J; Redmond, A D; Martin, M A

    1987-01-01

    In an attempt to reduce the number of people who die from a cardiac arrest in the Stockport area ambulances were equipped with automatic external defibrillator-pacemakers, and ambulance personnel were trained in their use. Over an 18 month period ambulance personnel attended 113 patients in cardiac arrest with these devices. One patient subsequently survived, and three patients survived for up to three days. The reasons for these poor initial results include the failure of bystanders to provide cardiopulmonary resuscitation, a delay in calling for the ambulance, and too few defibrillators being available. PMID:3107727

  10. Transvenous Implantable Cardioverter-Defibrillator Lead Reliability: Implications for Postmarket Surveillance

    PubMed Central

    Kramer, Daniel B; Hatfield, Laura A; McGriff, Deepa; Ellis, Christopher R; Gura, Melanie T; Samuel, Michelle; Retel, Linda Kallinen; Hauser, Robert G

    2015-01-01

    Background As implantable cardioverter-defibrillator technology evolves, clinicians and patients need reliable performance data on current transvenous implantable cardioverter-defibrillator systems. In addition, real-world reliability data could inform postmarket surveillance strategies directed by regulators and manufacturers. Methods and Results We evaluated Medtronic Sprint Quattro, Boston Scientific Endotak, and St Jude Medical Durata and Riata ST Optim leads implanted by participating center physicians between January 1, 2006 and September 1, 2012. Our analytic sample of 2653 patients (median age 65, male 73%) included 445 St Jude, 1819 Medtronic, and 389 Boston Scientific leads. After a median of 3.2 years, lead failure was 0.28% per year (95% CI, 0.19 to 0.43), with no statistically significant difference among manufacturers. Simulations based on these results suggest that detecting performance differences among generally safe leads would require nearly 10 000 patients or very long follow-up. Conclusions Currently marketed implantable cardioverter-defibrillator leads rarely fail, which may be reassuring to clinicians advising patients about risks and benefits of transvenous implantable cardioverter-defibrillator systems. Regulators should consider the sample size implications when designing comparative effectiveness studies and evaluating new technology for preventing sudden cardiac death. PMID:26025935

  11. The automatic external defibrillator-pacemaker: clinical rationale and engineering design.

    PubMed

    Aronson, A L; Haggar, B

    1986-01-01

    Prompt defibrillation is the cornerstone of therapy for out-of-hospital sudden cardiac arrest. Overwhelming evidence indicates that victims whose cardiac arrest is witnessed and whose ECG rhythm is ventricular fibrillation can be successfully resuscitated, with significant prolongation of life. The automatic external defibrillator-pacemaker (AEDP) is designed to be used by family members of patients with known heart disease, by basic level technicians in emergency rescue systems, and by lay rescuers in corporate-industrial-public environments. The AEDP is designed for safety and ease of use. It incorporates a highly sensitive and specific electronic diagnostic logic. It defibrillates and paces with a unique tongue-chest electrode system or through two adhesive chest electrodes. The AEDP should be a cost-effective device for the treatment of sudden cardiac arrest and can play a major role in public health strategies for optimizing care for this enormous problem.

  12. Inappropriate shock delivery due to interference between a washing machine and an implantable cardioverter defibrillator.

    PubMed

    Kolb, Christof; Schmieder, Sebastian; Schmitt, Claus

    2002-12-01

    Electromagnetic interference with implantable cardioverter defibrillators (ICD) can cause inappropriate delivery of therapies or temporary inhibition of ICD functions. The presented case describes electromagnetic interference between a washing machine and an ICD resulting in an inappropriate discharge of the device due to false detection of ventricular fibrillation.

  13. Inappropriate shock delivery by implantable cardioverter defibrillator due to electrical interference with washing machine.

    PubMed

    Chongtham, Dhanaraj Singh; Bahl, Ajay; Kumar, Rohit Manoj; Talwar, K K

    2007-05-31

    We report a patient with hypertrophic cardiomyopathy who received an inappropriate implantable cardioverter defibrillator shock due to electrical interference from a washing machine. This electrical interference was detected as an episode of ventricular fibrillation with delivery of shock without warning symptoms.

  14. Safety of Electromagnetic Articulography in Patients with Pacemakers and Implantable Cardioverter-Defibrillators

    ERIC Educational Resources Information Center

    Joglar, Jose A.; Nguyen, Carol; Garst, Diane M.; Katz, William F.

    2009-01-01

    Purpose: "Electromagnetic articulography (EMA)" uses a helmet to create alternating magnetic fields for tracking speech articulator movement. An important safety consideration is whether EMA magnetic fields interfere with the operation of speakers' pacemakers or implantable cardioverter-defibrillators (ICDs). In this investigation,…

  15. Implantable Cardiac Defibrillator Pocket Infection Due to a Previously Undescribed Cupriavidus Species▿

    PubMed Central

    Christensen, Joshua B.; Vitko, Nicholas P.; Voskuil, Martin I.; Castillo-Mancilla, Jose R.

    2010-01-01

    The genus Cupriavidus consists of Gram-negative, nonfermenting bacteria most of which are environmental organisms, though some species have been associated with human disease. We report the recovery and identification of an isolate that represents a previously undescribed species of Cupriavidus from an implantable cardiac defibrillator pocket infection. PMID:20427695

  16. Washing machine associated 50 Hz detected as ventricular fibrillation by an implanted cardioverter defibrillator.

    PubMed

    Sabaté, X; Moure, C; Nicolás, J; Sedó, M; Navarro, X

    2001-08-01

    This case report describes a patient with an automatic ICD who suffered a defibrillation shock without warning symptoms. An electrical interference can be observed in the stored EGM of the episode. The patient explained that the moment he felt the shock he was touching a washing machine. After correct grounding of this machine the patient did not suffer more inappropriate shocks.

  17. Transient ischaemic attack due to the lead of an implantable defibrillator in the left heart

    PubMed Central

    Alozie, Anthony; Westphal, Bernd; Yerebakan, Can; Steinhoff, Gustav

    2012-01-01

    A frequently underdiagnosed complication of pacemaker and implantable cardioverter defibrillator lead implantation is the unintentional advancement of the leads into the systemic circulation. We report a case encountered in our clinic in a 70-year old man evaluated in a neighbouring clinic with symptoms of transient ischaemic attack with initially unclear aetiology. Posterior–anterior chest X-rays suggested that the lead was in the left heart. This finding was confirmed by transthoracic and transoesophageal echocardiography. PMID:22108939

  18. Epicardial Implantable Cardioverter-Defibrillator in a 2-Month-Old Infant.

    PubMed

    Sughimoto, Koichi; Tsuchida, Yuta; Hayashi, Hidenori; Torii, Shinzo; Kitamura, Tadashi; Horai, Tetsuya; Miyaji, Kagami

    2017-03-01

    We describe the implantation of an implantable cardioverter defibrillator (ICD) in a 2-month-old infant with frequent sustained ventricular tachycardia (VT) refractory to antiarrhythmic agents. An epicardial ICD shock coil lead and pacing leads were placed, as was a cumbersome device console that was stored in a pocket between the left external and internal oblique muscles. These methods were safe and feasible even for such a small infant, and possible adverse events were avoided.

  19. Who should receive an implantable cardioverter-defibrillator after myocardial infarction?

    PubMed

    Mountantonakis, Stavros; Hutchinson, Mathew D

    2009-12-01

    Despite a decline in overall cardiovascular mortality, the incidence of sudden cardiac death (SCD) continues to rise. Patients who survive a myocardial infarction (MI) with depressed ejection fraction are at particularly high risk for SCD. The development of implantable cardioverter-defibrillators (ICDs) has revolutionized SCD prevention; however, despite the current fervor for device implantation, many unresolved questions remain about risk stratification in post-MI patients. This review presents the current indications and timing of ICD implantation for primary and secondary prevention of SCD after MI. Several conventional and investigational methods of risk stratification after MI, as well as current controversies regarding device implantation in specific patient populations, are also reviewed.

  20. Tachycardia detection in modern implantable cardioverter-defibrillators.

    PubMed

    Brüggemann, Thomas; Dahlke, Daniel; Chebbo, Amin; Neumann, Ilka

    2016-09-01

    Implantable cardioverter-defibrillators (ICD) have to reliably sense, detect, and treat malignant ventricular tachyarrhythmias. Inappropriate treatment of non life-threatening tachyarrhythmias should be avoided. This article outlines the functionality of ICDs developed and manufactured by BIOTRONIK. Proper sensing is achieved by an automatic sensitivity control which can be individually tailored to solve special under- and oversensing situations. The programming of detection zones for ventricular fibrillation (VF), ventricular tachycardia (VT), and zones to monitor other tachyarrhythmias is outlined. Dedicated single-chamber detection algorithms based on average heart rate, cycle length variability, sudden rate onset, and changes in QRS morphology as used in ICDs by BIOTRONIK are described in detail. Preconditions and confirmation algorithms for therapy deliveries as antitachycardia pacing (ATP) and high energy shocks are explained. Finally, a detailed description of the dual-chamber detection algorithm SMART is given. It comprises additional detection criteria as stability of atrial intervals, 1:1 conduction, atrial-ventricular (AV) multiplicity, AV trend, and AV regularity to differentiate between ventricular and supraventricular tachyarrhythmias.

  1. Third- and fourth-generation implantable cardioverter defibrillators: current status and future development.

    PubMed

    Saksena, S; Diaz, M L; Varanasi, S; Mathew, P; Berg, J; Krol, R B; Kaushik, R R

    1994-10-01

    Implantable cardioverter defibrillator (ICD) therapy has become the mainstay of therapy for patients with a history of sudden cardiac death or life-threatening ventricular arrhythmias. The current generation of ICDs used for secondary prevention combines features for tachycardia reversion with demand ventricular pacing, antitachycardia pacing, programmable shock therapy, and tachycardia events memory. Although demand pacing and defibrillation is indicated for primary prevention usage of ICDs, the application of antitachycardia pacing modes is more controversial. High energy cardioversion and defibrillation shocks remaining the mainstay of sudden death prevention will be redefined as more effective defibrillation shock modes and lead systems are developed. Fourth-generation ICD systems accomplished a significant reduction of device size and almost universal success using an endocardial lead configuration and pectoral implant. A variety of new directions of ICD therapy in clinical practice such as primary prevention applications and the adjunctive role of antiarrhythmic drug therapy are currently being examined in clinical trials. The concepts underlying initiation of tachyarrhythmias are being studied to develop new approaches to tachycardia prevention. These include rate support, subthreshold stimulation, and multiple site pacing. The current developments of ICD therapy promise continued growth of this technology.

  2. Dental management of a patient fitted with subcutaneous Implantable Cardioverter Defibrillator device and concomitant warfarin treatment.

    PubMed

    Shah, Altaf Hussain; Khalil, Hesham Saleh; Kola, Mohammed Zaheer

    2015-07-01

    Automated Implantable Cardioverter Defibrillators (AICD), simply known as an Implantable Cardioverter Defibrillator (ICD), has been used in patients for more than 30 years. An Implantable Cardioverter Defibrillator (ICD) is a small battery-powered electrical impulse generator that is implanted in patients who are at a risk of sudden cardiac death due to ventricular fibrillation, ventricular tachycardia or any such related event. Typically, patients with these types of occurrences are on anticoagulant therapy. The desired International Normalized Ratio (INR) for these patients is in the range of 2-3 to prevent any subsequent cardiac event. These patients possess a challenge to the dentist in many ways, especially during oral surgical procedures, and these challenges include risk of sudden death, control of post-operative bleeding and pain. This article presents the dental management of a 60 year-old person with an ICD and concomitant anticoagulant therapy. The patient was on multiple medications and was treated for a grossly neglected mouth with multiple carious root stumps. This case report outlines the important issues in managing patients fitted with an ICD device and at a risk of sudden cardiac death.

  3. Dental management of a patient fitted with subcutaneous Implantable Cardioverter Defibrillator device and concomitant warfarin treatment

    PubMed Central

    Shah, Altaf Hussain; Khalil, Hesham Saleh; Kola, Mohammed Zaheer

    2015-01-01

    Automated Implantable Cardioverter Defibrillators (AICD), simply known as an Implantable Cardioverter Defibrillator (ICD), has been used in patients for more than 30 years. An Implantable Cardioverter Defibrillator (ICD) is a small battery-powered electrical impulse generator that is implanted in patients who are at a risk of sudden cardiac death due to ventricular fibrillation, ventricular tachycardia or any such related event. Typically, patients with these types of occurrences are on anticoagulant therapy. The desired International Normalized Ratio (INR) for these patients is in the range of 2–3 to prevent any subsequent cardiac event. These patients possess a challenge to the dentist in many ways, especially during oral surgical procedures, and these challenges include risk of sudden death, control of post-operative bleeding and pain. This article presents the dental management of a 60 year-old person with an ICD and concomitant anticoagulant therapy. The patient was on multiple medications and was treated for a grossly neglected mouth with multiple carious root stumps. This case report outlines the important issues in managing patients fitted with an ICD device and at a risk of sudden cardiac death. PMID:26236132

  4. Capsule endoscopy in patients with cardiac pacemakers, implantable cardioverter defibrillators and left heart assist devices

    PubMed Central

    Bandorski, Dirk; Höltgen, Reinhard; Stunder, Dominik; Keuchel, Martin

    2014-01-01

    According to the recommendations of the US Food and Drug Administration and manufacturers, capsule endoscopy should not be used in patients carrying implanted cardiac devices. For this review we considered studies indexed (until 30.06.2013) in Medline [keywords: capsule endoscopy, small bowel endoscopy, cardiac pacemaker, implantable cardioverter defibrillator, interference, left heart assist device], technical information from Given Imaging and one own publication (not listed in Medline). Several in vitro and in vivo studies included patients with implanted cardiac devices who underwent capsule endoscopy. No clinically relevant interference was noticed. Initial reports on interference with a simulating device were not reproduced. Furthermore technical data of PillCam (Given Imaging) demonstrate that the maximum transmission power is below the permitted limits for cardiac devices. Hence, impairment of cardiac pacemaker, defibrillator or left ventricular heart assist device function by capsule endoscopy is not expected. However, wireless telemetry can cause dysfunction of capsule endoscopy recording. Application of capsule endoscopy is feasible and safe in patients with implanted cardiac devices such as pacemakers, cardioverter defibrillators, and left heart assist devices. Development of new technologies warrants future re-evaluation. PMID:24714370

  5. Single lead catheter of implantable cardioverter-defibrillator with floating atrial sensing dipole implanted via persistent left superior vena cava.

    PubMed

    Malagù, Michele; Toselli, Tiziano; Bertini, Matteo

    2016-04-26

    Persistent left superior vena cava (LSVC) is a congenital anomaly with 0.3%-1% prevalence in the general population. It is usually asymptomatic but in case of transvenous lead positioning, i.e., for pacemaker or implantable cardioverter defibrillator (ICD), may be a cause for significant complications or unsuccessful implantation. Single lead ICD with atrial sensing dipole (ICD DX) is a safe and functional technology in patients without congenital abnormalities. We provide a review of the literature and a case report of successful implantation of an ICD DX in a patient with LSVC and its efficacy in treating ventricular arrhythmias.

  6. Single lead catheter of implantable cardioverter-defibrillator with floating atrial sensing dipole implanted via persistent left superior vena cava

    PubMed Central

    Malagù, Michele; Toselli, Tiziano; Bertini, Matteo

    2016-01-01

    Persistent left superior vena cava (LSVC) is a congenital anomaly with 0.3%-1% prevalence in the general population. It is usually asymptomatic but in case of transvenous lead positioning, i.e., for pacemaker or implantable cardioverter defibrillator (ICD), may be a cause for significant complications or unsuccessful implantation. Single lead ICD with atrial sensing dipole (ICD DX) is a safe and functional technology in patients without congenital abnormalities. We provide a review of the literature and a case report of successful implantation of an ICD DX in a patient with LSVC and its efficacy in treating ventricular arrhythmias. PMID:27152145

  7. Inappropriate implantable cardioverter defibrillator shock from a transcutaneous muscle stimulation device therapy.

    PubMed

    Siu, Chung-Wah; Tse, Hung-Fat; Lau, Chu-Pak

    2005-06-01

    Inappropriate shock from implantable cardioverter defibrillator (ICD) may result from external electromagnetic interference (EMI), especially for unipolar ventricle sensing. Previous case reports and small in-vitro safety study suggested that endocardial bipolar lead system may be immune from EMI resulting from transcutaneous electrical neuromuscle stimulation (TENS) therapy. This report presents an unusual case of inappropriate discharge in a patient with ICD of endocardial bipolar lead system, receiving TENS from a commercially available device.

  8. Athletic participation in the young patient with an implantable cardioverter-defibrillator.

    PubMed

    Lampert, Rachel; Law, Ian

    2017-01-01

    The decision of whether to allow a young patient with an implantable cardioverter-defibrillator to continue to participate in sports is complex and multi-factorial. The positive physical and psychosocial impact of sports participation must be weighed against the potential adverse events associated with implantable cardioverter-defibrillators. Arrhythmias appear to be more prevalent in athletes and occur more frequently during physical activity or competition/practice, but there is growing evidence that device therapy is effective in athletes across a wide range of competitive sports. Failure of a device to convert a life-threatening arrhythmia, major injury from a shock, and increased lead failure have thus far not been reported in the prospective Implantable Cardioverter-Defibrillator Sports Registry, but follow-up remains relatively short. Thoughtful consideration of disease state, arrhythmia risk, and the potential dangers of device therapy during the desired sports is imperative before allowing participation. Frank discussion with children and families regarding the possibility of shocks during sports, as well as at other times, is imperative. Ongoing and future studies will help guide these decisions.

  9. Hospice Use Following Implantable Cardioverter-Defibrillator Implantation in Older Patients

    PubMed Central

    Reynolds, Matthew R.; Normand, Sharon-Lise; Parzynski, Craig S.; Spertus, John A.; Mor, Vincent; Mitchell, Susan L.

    2016-01-01

    Background— Older recipients of implantable cardioverter-defibrillators (ICDs) are at increased risk for short-term mortality in comparison with younger patients. Although hospice use is common among decedents aged >65, its use among older ICD recipients is unknown. Methods and Results— Medicare patients aged >65 matched to data in the National Cardiovascular Data Registry – ICD Registry from January 1, 2006 to March 31, 2010 were eligible for analysis (N=194 969). The proportion of ICD recipients enrolled in hospice, cumulative incidence of hospice admission, and factors associated with time to hospice enrollment were evaluated. Five years after device implantation, 50.9% of patients were either deceased or in hospice. Among decedents, 36.8% received hospice services. The cumulative incidence of hospice enrollment, accounting for the competing risk of death, was 4.7% (95% confidence interval [CI], 4.6%–4.8%) within 1 year and 21.3% (95% CI, 20.7%–21.8%) at 5 years. Factors most strongly associated with shorter time to hospice enrollment were older age (adjusted hazard ratio, 1.77; 95% CI, 1.73–1.81), class IV heart failure (versus class I; adjusted hazard ratio, 1.79; 95% CI, 1.66–1.94); ejection fraction <20 (adjusted hazard ratio, 1.57; 95% CI, 1.48–1.67), and greater hospice use among decedents in the patients’ health referral region. Conclusions— More than one-third of older patients dying with ICDs receive hospice care. Five years after implantation, half of older ICD recipients are either dead or in hospice. Hospice providers should be prepared for ICD patients, whose clinical trajectories and broader palliative care needs require greater focus. PMID:27016104

  10. Automatic external defibrillators in the sports arena: the right place, the right time.

    PubMed

    Cantwell, J D

    1998-12-01

    At first glance, the idea of having automatic external defibrillators (AEDs) at sports events may seem curious, since spectator sports are the domain of young, healthy athletes. Yet athletes are not entirely free of cardiac risk. More important, there are many other people at sports events (officials, coaches, fans) who are at risk for cardiac arrest. In just one example, baseball umpire John McSherry suffered a fatal heart attack before a national TV audience during the Cincinnati Reds' home opener in April 1996.

  11. T-wave alternans negative coronary patients with low ejection and benefit from defibrillator implantation

    NASA Technical Reports Server (NTRS)

    Hohnloser, S. H.; Ikeda, T.; Bloomfield, D. M.; Dabbous, O. H.; Cohen, R. J.

    2003-01-01

    In a trial of prophylactic implantation of a defibrillator, a mortality benefit was seen among patients with previous myocardial infarction and a left-ventricular ejection fraction of 0.30 or less. We identified 129 similar patients from two previously published clinical trials in which microvolt T-wave alternans testing was prospectively assessed. At 24 months of follow-up, no sudden cardiac death or cardiac arrest was seen among patients who tested T-wave alternans negative, compared with an event rate of 15.6% among the remaining patients. Testing of T-wave alternans seems to identify patients who are at low risk of ventricular tachyarrhythmic event and who may not benefit from defibrillator therapy.

  12. Epileptic seizure in a patient with an implantable cardioverter-defibrillator: Quo vadis right ventricular lead?

    PubMed

    Wedekind, Horst; Rozhnev, Andrey; Kleine-Katthöfer, Peter; Kranig, Wolfgang

    2016-03-01

    The case of a 77-year-old man admitted for suspected epileptic seizure is reported. Patient history showed implantation of a single-chamber implantable cardioverter-defibrillator (ICD) after cardiac arrest in 2007 with replacement in 2012 due to battery depletion; the patient reported no previous syncope, unconsciousness or seizures. Interrogation records of the ICD showed five ventricular tachyarrhythmia episodes that corresponded to the "seizure". Further examination revealed incorrect position of the RV-lead. Diagnosis was a provoked epileptic seizure due to undersensing of ventricular tachycardia because of improper ICD lead implantation in the coronary sinus. Treatment consisted of implantation of a new device with an additional ICD lead into the right ventricle.

  13. Marked attenuation of shock burden by the use of antitachycardia pacing therapy in a patient with an implanted cardioverter-defibrillator.

    PubMed

    Ganjehei, Leila; Nazeri, Alireza; Massumi, Ali; Razavi, Mehdi

    2012-01-01

    A 76-year-old man was admitted to our institution for elective exchange of his implanted cardioverter-defibrillator generator. Nine years earlier, he had been diagnosed with nonischemic cardiomyopathy and nonsustainable ventricular tachycardia. At that time, he had received a single-chamber implanted cardioverter-defibrillator, which was upgraded to a dual-chamber implanted cardioverter-defibrillator 3 years later. In the course of the current admission, routine device interrogation during exchange of the patient's implanted cardioverter-defibrillator generator revealed 150 episodes of ventricular tachycardia in the preceding 7 months, 137 of which had been successfully treated by antitachycardia pacing therapy without shock. These findings show the remarkable effectiveness of antitachycardia pacing in terminating ventricular tachycardia while preventing the delivery of shocks, minimizing patient discomfort, and avoiding implanted cardioverter-defibrillator battery depletion.

  14. Fish-oil supplementation in patients with implantable cardioverter defibrillators: a meta-analysis

    PubMed Central

    Jenkins MD, David J.A.; Josse, Andrea R.; Beyene, Joseph; Dorian, Paul; Burr, Michael L.; LaBelle, Roxanne; Kendall, Cyril W.C.; Cunnane, Stephen C.

    2008-01-01

    Background A recent Cochrane meta-analysis did not confirm the benefits of fish and fish oil in the secondary prevention of cardiac death and myocardial infarction. We performed a meta-analysis of randomized controlled trials that examined the effect of fish-oil supplementation on ventricular fibrillation and ventricular tachycardia to determine the overall effect and to assess whether heterogeneity exists between trials. Methods We searched electronic databases (MEDLINE, EMBASE, The Cochrane Central Register of Controlled Trials, CINAHL) from inception to May 2007. We included randomized controlled trials of fish-oil supplementation on ventricular fibrillation or ventricular tachycardia in patients with implantable cardioverter defibrillators. The primary outcome was implantable cardioverter defibrillator discharge. We calculated relative risk [RR] for outcomes at 1-year follow-up for each study. We used the DerSimonian and Laird random-effects methods when there was significant heterogeneity between trials and the Mantel-Hanzel fixed-effects method when heterogeneity was negligible. Results We identified 3 trials of 1–2 years' duration. These trials included a total of 573 patients who received fish oil and 575 patients who received a control. Meta-analysis of data collected at 1 year showed no overall effect of fish oil on the relative risk of implantable cardioverter defibrillator discharge. There was significant heterogeneity between trials. The second largest study showed a significant benefit of fish oil (relative risk [RR] 0.74, 95% confidence interval [CI] 0.56–0.98). The smallest showed an adverse tendency at 1 year (RR 1.23, 95% CI 0.92–1.65) and significantly worse outcome at 2 years among patients with ventricular tachycardia at study entry (log rank p = 0.007). Conclusion These data indicate that there is heterogeneity in the response of patients to fish-oil supplementation. Caution should be used when prescribing fish-oil supplementation for

  15. Subglandular placement of an implantable cardioverter-defibrillator for an improved cosmetic outcome.

    PubMed

    Wright, Cassidy D; Roehl, Kendall R; Stephen Huang, Shoei K; Mahabir, Raman C

    2013-11-01

    Implantable cardioverter-defibrillator (ICD) technology has progressed through the years decreasing the size of the device, and its effectiveness in preventing sudden cardiac death has made it a mainstay of treatment for many patients. As the use of ICDs in younger patients has increased, issues with placement of an ICD in the usual prepectoral, infraclavicular region have arisen. Subglandular placement through an inframammary incision provides a unique approach and an aesthetically pleasing outcome for ICD placement. We present a review of the current literature and 3 cases of young female patients who had placement of an ICD using this approach.

  16. Inappropriate implantable cardioverter-defibrillator magnet-mode switch induced by a laptop computer.

    PubMed

    Tiikkaja, Maria; Aro, Aapo; Alanko, Tommi; Lindholm, Harri; Hietanen, Maila

    2012-06-01

    An implantable cardioverter-defibrillator (ICD) experienced electromagnetic interference from a laptop computer's hard disk. The patient with the ICD was using his laptop computer at home while lying on his bed. The laptop was positioned on his chest, when he heard a beeping sound from the ICD, indicating magnet mode conversion. This situation was replicated in a controlled environment, and the conversion was found to be due to the static magnetic field produced by the laptop's hard disk. The ICD's conversion to magnet mode can be dangerous because it ends all tachyarrhythmia detections and therapies.

  17. Promoting health-related quality of life in patients with an implantable cardioverter defibrillator.

    PubMed

    Wong, Florence

    2017-03-01

    Implantable cardioverter defibrillators (ICDs) are an effective treatment to reduce mortality rates in patients who are at risk of sudden cardiac death. However, ICDs have been shown to reduce the patient's mental and physical health-related quality of life. It is essential for nurses to have an understanding of the factors associated with health-related quality of life in patients with ICDs, to develop appropriate strategies to improve patient care and optimise quality of life. A case study is included in this article to enhance understanding of the effects these devices can have on a patient's quality of life.

  18. Long-Term Survival Following Cardiac Arrest Without Implantable Defibrillator Protection in a Hypertrophic Cardiomyopathy Patient

    PubMed Central

    Cetin, Mustafa; Ucar, Ozgul; Canbay, Alper; Cetin, Zehra Guven; Cicekcioglu, Hulya; Diker, Erdem

    2011-01-01

    Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden cardiac death in young people. Implantable cardioverter defibrillator (ICD) is the optimal therapy in patients with HCM, both for primary or secondary prevention of sudden death. Left ventricular systolic function in HCM is usually normal. However, in few patients, HCM has been reported to progress to a state that is characterized by left ventricular dilation and systolic dysfunction, resembling dilated cardiomyopathy (DCM). Although arrhythmias are common in HCM, advanced or complete atrioventricular block (AV) is very rare. This case report describes a HCM patient who progressed to DCM with advanced AV block and survived 31 years following cardiac arrest without ICD protection.

  19. Safety and feasibility of dobutamine stress echocardiography in patients with implantable cardioverter defibrillators.

    PubMed

    Elhendy, Abdou; Windle, John; Porter, Thomas R

    2003-08-15

    Coronary artery disease is the underlying etiology of left ventricular dysfunction and arrhythmias in most patients who receive implantable cardioverter defibrillators (ICDs). The aim of this study was to assess the safety and feasibility of dobutamine stress echocardiography (DSE) in patients with an ICD. DSE (dobutamine up to 50 microg/kg/min, atropine up to 2 mg) was performed in 87 patients with an ICD and known or suspected coronary artery disease. The ICD was inactivated before the stress test and reactivated after the study; no serious complications occurred. DSE is a safe and feasible method for evaluating myocardial ischemia in patients with an ICD.

  20. "Pseudo" Faraday cage: a solution for telemetry link interaction between a left ventricular assist device and an implantable cardioverter defibrillator.

    PubMed

    Jacob, Sony; Cherian, Prasad K; Ghumman, Waqas S; Das, Mithilesh K

    2010-09-01

    Patients implanted with left ventricular assist devices (LVAD) may have implantable cardioverter defibrillators (ICD) implanted for sudden cardiac death prevention. This opens the possibility of device-device communication interactions and thus interferences. We present a case of such interaction that led to ICD communication failure following the activation of an LVAD. In this paper, we describe a practical solution to circumvent the communication interference and review the communication links of ICDs and possible mechanisms of ICD-LVAD interactions.

  1. Battery and capacitor technology for uniform charge time in implantable cardioverter-defibrillators

    NASA Astrophysics Data System (ADS)

    Skarstad, Paul M.

    Implantable cardioverter-defibrillators (ICDs) are implantable medical devices designed to treat ventricular fibrillation by administering a high-voltage shock directly to the heart. Minimizing the time a patient remains in fibrillation is an important goal of this therapy. Both batteries and high-voltage capacitors used in these devices can display time-dependency in performance, resulting in significant extension of charge time. Altering the electrode balance in lithium/silver vanadium oxide batteries used to power these devices has minimized time-dependent changes in battery resistance. Charge-interval dependent changes in capacitor cycling efficiency have been minimized for stacked-plate aluminum electrolytic capacitors by a combination of material and processing factors.

  2. Life-saving implantable cardioverter defibrillator therapy in cardiac AL amyloidosis

    PubMed Central

    Patel, Ketna S; Hawkins, Philip N; Whelan, Carol J; Gillmore, Julian D

    2014-01-01

    Cardiac involvement is the main determinant of prognosis in systemic monoclonal immunoglobulin light chain (AL) amyloidosis. Ventricular arrhythmias and sudden cardiac death are not uncommon. The electrical events that precede sudden death, and their potential to be treated effectively, remain undefined. There are no European guidelines for the use of implantable cardioverter defibrillator (ICD) in amyloidosis. ICDs in general are not usually offered to patients with a life expectancy of less than 1 year. We describe a patient who presented with cardiac AL amyloidosis who underwent prophylactic ICD implantation for the prevention of sudden cardiac death during treatment with chemotherapy, in whom life-threatening ventricular arrhythmia was successfully terminated over a 3-year period. PMID:25535224

  3. Florid psychopathology in patients receiving shocks from implanted cardioverter-defibrillators

    PubMed Central

    Bourke, J.; Turkington, D.; Thomas, G.; McComb, J.; Tynan, M.

    1997-01-01

    Objectives—To increase awareness of the potential for disabling anxiety and depression in patients receiving shocks from implanted cardioverter-defibrillators (ICDs).
Patients and methods—ICDs are implanted in patients at this hospital for control of serious ventricular tachyarrhythmias inadequately controlled by drug treatment, who are unsuitable for map guided antiarrhythmic surgery. All are reviewed regularly at a dedicated ICD clinic and are advised to make contact between visits if they experience shocks. Symptoms of anxiety or depression were not actively sought, nor was a patient support group operating at the time of this data collection. When overt psychopathology was identified, patients were referred to a designated psychiatrist for management.
Results—Over a six year period, six (17%) of 35 patients with ICDs developed florid psychiatric problems after experiencing shocks. None had premorbid psychiatric predisposition. Of the six patients suffering severe psychiatric problems, four were men, their age range was 30-63 years, and left ventricular ejection fraction was 18-40%. All shocks were appropriate for clinical arrhythmias and ranged in frequency from two in six months to 111 in 24 hours. All six patients manifested severe anxiety, focused on fear of future shocks. Depression was also evident in three patients and two had become housebound. All responded within weeks to anxiolytic or antidepressant drugs, combined with relaxation and cognitive therapies. Ongoing psychiatric therapy was refused by one patient, and was required for between three and 18 months in the remainder. One patient died and one received a cardiac transplant during the follow up period (median 27.5 months, range 8-43).
Conclusions—Because ICD implantation occurs against a complex medical background with inevitable psychological stress, all such patients should be considered at high risk for developing psychopathology.

 Keywords: implantable cardioverter-defibrillators

  4. Legal aspects of the application of the lay rescuer automatic external defibrillator (AED) program in South Korea.

    PubMed

    Bae, Hyuna

    2008-04-01

    The American Heart Association has stated that the automatic external defibrillator (AED) is a promising method for achieving rapid defibrillation, and emphasized that AED training and use should be available in every community. The demonstrated safety and effectiveness of the AED make it ideally suited for the delivery of early defibrillation by trained laypersons, and the placement of AEDs in selected locations for immediate use by trained laypersons may enable critical intervention that can significantly increase survival from out-of-hospital cardiac arrest. The American Heart Association recommends the installation of AEDs in public locations such as airports, thus allowing laypersons to conduct defibrillation and cardiopulmonary resuscitation on the occasion of adverse cardiopulmonary events. In Korea, the Ministry of Health and Welfare officially prohibits the installation of AEDs in public locations on the grounds that cardiopulmonary resuscitation and defibrillation are understood as medical practices that can be conducted only by licensed medical practitioners. The purpose of this article is to discuss the necessity for AEDs and the appropriate process for their implementation in Korea, by examining the current pre-AED status of Korea and the relevant legal aspects.

  5. Economical aspect of PET/CT-guided diagnosis of suspected infective endocarditis in a patient with implantable cardioverter-defibrillator.

    PubMed

    Farkowski, Michal M; Milkowski, Maciej; Dziuk, Mirosław; Pytkowski, Mariusz; Marciniak, Marta; Kraska, Alicja; Szwed, Hanna; Sterlinski, Maciej

    2014-01-01

    We present a case report of potential reduction of hospitalization costs due to utilization of PET/CT in a diagnostic work-up of a patient with an implantable cardioverter-defibrillator and suspicion of infective endocarditis. The PET/CT scan would have shorten hospital stay, prevented clinical complications and reduced the cost of hospitalization by 45%.

  6. Extended charge banking model of dual path shocks for implantable cardioverter defibrillators

    PubMed Central

    Dosdall, Derek J; Sweeney, James D

    2008-01-01

    Background Single path defibrillation shock methods have been improved through the use of the Charge Banking Model of defibrillation, which predicts the response of the heart to shocks as a simple resistor-capacitor (RC) circuit. While dual path defibrillation configurations have significantly reduced defibrillation thresholds, improvements to dual path defibrillation techniques have been limited to experimental observations without a practical model to aid in improving dual path defibrillation techniques. Methods The Charge Banking Model has been extended into a new Extended Charge Banking Model of defibrillation that represents small sections of the heart as separate RC circuits, uses a weighting factor based on published defibrillation shock field gradient measures, and implements a critical mass criteria to predict the relative efficacy of single and dual path defibrillation shocks. Results The new model reproduced the results from several published experimental protocols that demonstrated the relative efficacy of dual path defibrillation shocks. The model predicts that time between phases or pulses of dual path defibrillation shock configurations should be minimized to maximize shock efficacy. Discussion Through this approach the Extended Charge Banking Model predictions may be used to improve dual path and multi-pulse defibrillation techniques, which have been shown experimentally to lower defibrillation thresholds substantially. The new model may be a useful tool to help in further improving dual path and multiple pulse defibrillation techniques by predicting optimal pulse durations and shock timing parameters. PMID:18673561

  7. Underutilization of Implantable Cardioverter Defibrillator in Primary Prevention of Sudden Cardiac Arrest

    PubMed Central

    Lakshmanadoss, Umashankar; Sherazi, Saadia; Aggarwal, Ashim; Hsi, David; Aktas, Mehmet K.; Daubert, James P.; Shah, Abrar H

    2011-01-01

    Background The aim of this study was to evaluate the overall use of implantable cardioverter defibrillators (ICD) for primary prevention of sudden cardiac arrest (SCA), among eligible patients from an outpatient cardiology clinic and to determine what factors might contribute to underutilization of ICDs. Methods This report was a retrospective chart review of patients with ischemic or non-ischemic cardiomyopathy and left ventricular ejection fraction ≤ 35% from an outpatient cardiology practice from January 2005 to May 2008. These patients met the eligibility criteria for ICD implantation for primary prevention of SCA. A detailed review of medical records captured distribution of ICD implantation including future plans for ICD implant, patient preference against ICD use, presence of severe co-morbidities, and any other documented reasons/contraindications regarding ICD implantation. Results Of the 275 patients who were eligible for ICD for primary prevention of SCA, 119 (43%) had an ICD implantation. ICDs were used in 84 (48%) eligible men and 35 (35%) eligible women (P 0.02). Among 156 (57%) patients who did not receive ICD, 79 (28%) had severe co-morbidities precluding them from having ICD. Twenty-six patients (10%) refused to have ICD implanted. The remaining 51 (19%) patient charts did not include any documentation regarding ICD use (future plan or contraindication). Conclusions ICDs are underutilized for primary prevention of SCA, with rates of use being lowest among eligible women. This underutilization exists even after accounting for patient preferences and presence of severe co-morbid conditions that might make an otherwise eligible patient not a suitable candidate for ICD implantation.

  8. Changes in Daily Life of Iranian Patients with implantable Cardioverter Defibrillator: A Qualitative Study

    PubMed Central

    Pasyar, Nilofar; Sharif, Farkhondeh; Rakhshan, Mahnaz; Nikoo, Mohammad Hossein; Navab, Elham

    2017-01-01

    ABSTRACT Background: Although Implantable Cardioverter Defibrillator (ICD) saves the life of patients with life-threatening ventricular dysrhythmias, it causes various challenges in their life span. Considering the increase in the number of ICD users, more knowledge is required regarding changes in the patients’ life after device implantation. The aim of this study was description of changes in daily life of patients after ICD implantation Methods: This qualitative study was conducted through content analysis method. The participants were selected through purposive sampling. They included 3 women and 9 men whose ages ranged from 24 to 74 years, with the mean age of 42.58+1.55 years. They had implanted ICDs in order to treat life-threatening dysrhythmias. The study data were collected through interview and field notes from November 2013 to October 2014. The data were simultaneously analyzed using constant comparative analysis. Results: Through analysis of the study data, 2 categories were emerged representing dimensions of changes in daily life of the patients with ICD. These categories were changes in the social role and familial challenges after implantation. Change in social role included the following subcategories: “Change in manifestation of routines”, “Shift in leisure time”, “Change in job and education status”, and “Change in interaction between the patient and society members”. In addition, familial challenges after implantation consisted of 2 subcategories, namely “Difficulty in marriage” and “ICD implantation and a range of familial changes”. Conclusion: The study findings can be of great importance in nurses’ clinical practice for providing the patients with holistic care, education, support, and follow-up. They can also be used as a guide assisting clinical treatment of the patients with ICD.

  9. Current implantable cardioverter-defibrillator programming in Europe: the results of the European Heart Rhythm Association survey.

    PubMed

    Proclemer, Alessandro; Grazia Bongiorni, Maria; Etsner, Heidi; Todd, Derick; Sciaraffia, Elena; Blomström-Lundqvist, Carina

    2014-06-01

    The purpose of this European Heart Rhythm Association (EHRA) survey was to examine the current practice on the choice of implantable cardioverter-defibrillator (ICD) type, use of defibrillation testing, and ICD programming for detection and therapy of ventricular arrhythmias. In accordance with recent guidelines and the results of observational studies, the majority of EHRA research network centres reported a high utilization rate of dual-chamber ICDs in the presence of symptomatic and asymptomatic sinus node dysfunction, biventricular ICD in high-degree atrioventricular block and QRS duration <120 ms, and a limited use of defibrillation testing either in primary and secondary prevention settings. Activation of the long ventricular tachycardia (VT) detection window, slow VT zone, antitachycardia pacing before shock for slow and fast VT, and atrial tachyarrhythmia discrimination were considered useful in ICD programming for the majority of patients.

  10. Guidelines on the management of implantable cardioverter defibrillators at the end of life.

    PubMed

    Datino, T; Rexach, L; Vidán, M T; Alonso, A; Gándara, Á; Ruiz-García, J; Fontecha, B; Martínez-Sellés, M

    2014-01-01

    This article is a joint document of the Spanish Society of Geriatrics and Gerontology, the Spanish Society of Palliative Care and the Section of Geriatric Cardiology of the Spanish Society of Cardiology. Its aim is to address the huge gap that exists in Spain with regard to the management of implantable cardioverter defibrillators (ICDs) in the final stages of life. It is increasingly common to find patients carrying these devices that are in the terminal stage of an advanced disease. This occurs in patients with advanced heart disease and subsequent heart failure refractory to treatment but also in a patient with an ICD who develops cancer disease, organ failure or other neurodegenerative diseases with poor short-term prognosis. The vast majority of these patients are over 65, so the paper focuses particularly on the elderly who are in this situation, but the decision-making process is similar in younger patients with ICDs who are in the final phase of their life.

  11. [Guidelines on the management of implantable cardioverter defibrillators at the end of life].

    PubMed

    Datino, T; Rexach, L; Vidán, M T; Alonso, A; Gándara, Á; Ruiz-García, J; Fontecha, B; Martínez-Sellés, M

    2014-01-01

    This article is a joint document of the Spanish Society of Geriatrics and Gerontology, the Spanish Society of Palliative Care and the Section of Geriatric Cardiology of the Spanish Society of Cardiology. Its aim is to address the huge gap that exists in Spain with regard to the management of implantable cardioverter defibrillators (ICDs) in the final stages of life. It is increasingly common to find patients carrying these devices that are in the terminal stage of an advanced disease. This occurs in patients with advanced heart disease and subsequent heart failure refractory to treatment but also in a patient with an ICD who develops cancer disease, organ failure or other neurodegenerative diseases with poor short-term prognosis. The vast majority of these patients are over 65, so the paper focuses particularly on the elderly who are in this situation, but the decision-making process is similar in younger patients with ICDs who are in the final phase of their life.

  12. Psychological vulnerability, ventricular tachyarrhythmias and mortality in implantable cardioverter defibrillator patients: is there a link?

    PubMed

    Pedersen, Susanne S; Brouwers, Corline; Versteeg, Henneke

    2012-07-01

    Implantable cardioverter defibrillator (ICD) therapy is the first-line treatment for the prevention of sudden cardiac death. Despite the demonstrated survival benefits of the ICD, predicting which patients will die from a ventricular tachyarrhythmia remains a major challenge. So far, psychological factors have not been considered as potential risk markers that might enhance the prediction of sudden cardiac death. This article evaluates the evidence for a link between psychological vulnerability, ventricular tachyarrhythmias and mortality and the pathways that might explain such a link. This review demonstrates that there is cumulative evidence supporting a link between psychological vulnerability and risk of ventricular tachyarrhythmias and mortality in ICD patients independent of disease severity and other biomedical risk factors. It may be premature to include psychological factors in risk algorithms, but information on the psychological profile of the patient may help to optimize the management and care of these patients in clinical practice.

  13. MR Imaging in Patients with Cardiac Pacemakers and Implantable Cardioverter Defibrillators.

    PubMed

    Sommer, Torsten; Bauer, Wolfgang; Fischbach, Katharina; Kolb, Christof; Luechinger, Roger; Wiegand, Uwe; Lotz, Joachim; Eitel, Ingo; Gutberlet, Matthias; Thiele, Holger; Schild, Hans H; Kelm, Malte; Quick, Harald H; Schulz-Menger, Jeanette; Barkhausen, Jörg; Bänsch, Dietmar

    2017-02-15

    This joint consensus paper of the German Roentgen Society and the German Cardiac Society provides physical and electrophysiological background information and specific recommendations for the procedural management of patients with cardiac pacemakers (PM) and implantable cardioverter defibrillators (ICD) undergoing magnetic resonance (MR) imaging. The paper outlines the responsibilities of radiologists and cardiologists regarding patient education, indications, and monitoring with modification of MR sequences and PM/ICD reprogramming strategies being discussed in particular. The aim is to optimize patient safety and to improve legal clarity in order to facilitate the access of SM/ICD patients to MR imaging. Key Points:  · Conventional PM and ICD systems are no longer an absolute but rather a relative contraindication for performing an MR examination. Procedural management includes the assessment of the individual risk/benefit ratio, comprehensive patient informed consent about specific risks and "off label" use, extensive PM/ICD-related and MR-related safety precautions to reduce these risks to the greatest extent possible, as well as adequate monitoring techniques.. · MR conditional pacemaker and ICD systems have been tested and approved for MR examination under specific conditions ("in-label" use). Precise understanding of and compliance with the terms of use for the specific pacemaker system are essential for patient safety.. · The risk for an ICD patient during MR examinations is to be considered significantly higher compared to PM patients due to the higher vulnerability of the structurally damaged myocardium and the higher risk of irreversible damage to conventional ICD systems. The indication for a MR examination of an ICD patient should therefore be determined on a stricter basis and the expected risk/benefit ratio should be critically reviewed.. · This complex subject requires close collaboration between radiology and cardiology.. Citation Format

  14. Clinical Course After Cardioverter-Defibrillator Implantation: Chagasic Versus Ischemic Patients

    PubMed Central

    Pereira, Francisca Tatiana Moreira; Rocha, Eduardo Arrais; Monteiro, Marcelo de Paula Martins; Lima, Neiberg de Alcantara; Rodrigues Sobrinho, Carlos Roberto Martins; Pires Neto, Roberto da Justa

    2016-01-01

    Background: The outcome of Chagas disease patients after receiving implantable cardioverter defibrillator (ICD) is still controversial. Objective: To compare clinical outcomes after ICD implantation in patients with chronic Chagas cardiomyopathy (CCC) and ischemic heart disease (IHD). Methods: Prospective study of a population of 153 patients receiving ICD (65 with CCC and 88 with IHD). The devices were implanted between 2003 and 2011. Survival rates and event-free survival were compared. Results: The groups were similar regarding sex, functional class and ejection fraction. Ischemic patients were, on average, 10 years older than CCC patients (p < 0.05). Patients with CCC had lower schooling and monthly income than IHD patients (p < 0.05). The number of appropriate therapies was 2.07 higher in CCC patients, who had a greater incidence of appropriate shock (p < 0.05). Annual mortality rate and electrical storm incidence were similar in both groups. There was no sudden death in CCC patients, and only one in IHD patients. Neither survival time (p = 0.720) nor event-free survival (p = 0.143) significantly differed between the groups. Conclusion: CCC doubles the risk of receiving appropriate therapies as compared to IHD, showing the greater complexity of arrhythmias in Chagas patients. PMID:27411097

  15. No Electromagnetic Interference Occurred in a Patient with a HeartMate II Left Ventricular Assist System and a Subcutaneous Implantable Cardioverter-Defibrillator

    PubMed Central

    Raman, Ajay Sundara; Kar, Biswajit; Loyalka, Pranav; Hariharan, Ramesh

    2016-01-01

    The use of subcutaneous implantable cardioverter-defibrillators is a novel option for preventing arrhythmia-mediated cardiac death in patients who are at risk of endovascular-device infection or in whom venous access is difficult. However, the potential for electromagnetic interference between subcutaneous defibrillators and left ventricular assist devices is largely unknown. We report the case of a 24-year-old man in whom we observed no electromagnetic interference between a subcutaneous implanted cardioverter-defibrillator and a HeartMate II Left Ventricular Assist System, at 3 different pump speeds. To our knowledge, this is the first report of such findings in this circumstance. PMID:27127441

  16. The Gulf Implantable Cardioverter-defibrillator Registry: Rationale, Methodology, and Implementation

    PubMed Central

    Alsheikh-Ali, Alawi A.; Hersi, Ahmad S.; Hamad, Adel K. S.; Al Fagih, Ahmed R.; Al-Samadi, Faisal M.; Almusaad, Abdulmohsen M.; Bokhari, Fayez A.; Al-Kandari, Fawzia; Al-Ghamdi, Bandar S.; Al Rawahi, Najib; Asaad, Nidal; Alkaabi, Salem; Daoulah, Amin; Zaky, Hosam A.; Elhag, Omer; Al Hebaishi, Yahya S.; Sweidan, Raed; Alanazi, Haitham; Chase, David; Sabbour, Hani; Al Meheiri, Mohammad; Al Abri, Ismail; Amin, Mohammad; Dagriri, Khaled; Ahmed, Adil O.; Shafquat, Azam; Khan, Shahul Hameed

    2015-01-01

    Background: The implantable cardioverter-defibrillator (ICD) is effective in the prevention of sudden cardiac death in high-risk patients. Little is known about ICD use in the Arabian Gulf. We designed a study to describe the characteristics and outcomes of patients receiving ICDs in the Arab Gulf region. Methods: Gulf ICD is a prospective, multi-center, multinational, and observational study. All adult patients 18 years or older, receiving a de novo ICD implant and willing to sign a consent form will be eligible. Data on baseline characteristics, ICD indication, procedure and programing, in-hospital, and 1-year outcomes will be collected. Target enrollment is 1500 patients, which will provide adequate precision across a wide range of expected event rates. Results: Fifteen centers in six countries are enrolling patients (Saudi Arabia, United Arab Emirates, Kuwait, Oman, Bahrain, and Qatar). Two-thirds of the centers have dedicated electrophysiology laboratories, and in almost all centers ICDs are implanted exclusively by electrophysiologists. Nearly three-quarters of the centers reported annual ICD implant volumes of ≤150 devices, and pulse generator replacements constitute <30% of implants in the majority of centers. Enrollment started in December 2013, and accrual rate increased as more centers entered the study reaching an average of 98 patients per month. Conclusions: Gulf ICD is the first prospective, observational, multi-center, and multinational study of the characteristics and, the outcomes of patients receiving ICDs in the Arab Gulf region. The study will provide valuable insights into the utilization of and outcomes related to ICD therapy in the Gulf region. PMID:26900416

  17. Prognosis after Implantation of Cardioverter-Defibrillators in Korean Patients with Brugada Syndrome

    PubMed Central

    Son, Myoung Kyun; Byeon, Kyeongmin; Park, Seung-Jung; Kim, June Soo; Nam, Gi-Byoung; Choi, Kee-Joon; Kim, You-Ho; Park, Sang Weon; Kim, Young-Hoon; Park, Hyung Wook; Cho, Jeong Gwan

    2014-01-01

    Purpose Our study aims to analyze prognosis after implantable cardioverter-defibrillator (ICD) implantation in Korean patients with Brugada syndrome (BrS). Materials and Methods This was a retrospective study of BrS patients implanted with an ICD at one of four centers in Korea between January 1998 and April 2012. Sixty-nine patients (68 males, 1 female) were implanted with an ICD based on aborted cardiac arrest (n=38, 55%), history of syncope (n=17, 25%), or induced ven tricular tachyarrhythmia on electrophysiologic study in asymptomatic patients (n=14, 20%). A family history of sudden cardiac death and a spontaneous type 1 electrocardiography (ECG) were noted in 13 patients (19%) and 44 patients (64%), respectively. Results During a mean follow-up of 59±46 months, 4.6±5.5 appropri ate shocks were delivered in 19 patients (28%). Fourteen patients (20%) experienced 5.2±8.0 inappropriate shocks caused by supraventricular arrhythmia, lead failure, or abnormal sensing. Six patients were admitted for cardiac causes during follow-up, but no cardiac deaths occurred. An episode of aborted cardiac arrest was a significant predictor of appropriate shock, and the composite of cardiac events in the Cox pro portional hazard model [hazard ratio (95% confidence interval) was 11.34 (1.31-97.94) and 4.78 (1.41-16.22), respectively]. However, a spontaneous type 1 ECG was not a predictor of cardiac events. Conclusion Appropriate shock (28%) and inappropriate shock (20%) were noted during a mean follow-up of 59±46 months in Korean BrS patients implanted with an ICD. An episode of aborted cardiac ar rest was the most powerful predictor of cardiac events. PMID:24339285

  18. Early out-of-hospital experience with an impedance-compensating low-energy biphasic waveform automatic external defibrillator.

    PubMed

    White, R D

    1997-11-01

    Impedance-compensating low-energy biphasic truncated exponential (BTE) waveforms are effective in transthoracic defibrillation of short-duration ventricular fibrillation (VF). However, the BTE waveform has not been examined in out-of-hospital cardiac arrest (OHCA) with patients in prolonged VF often associated with myocardial ischemia. The objective of this study was to evaluate the BTE waveform automatic external defibrillator (AED) in the out-of-hospital setting with long-duration VF. AEDs incorporating a 150-J BTE waveform were placed in 12 police squad cars and 4 paramedic-staffed advanced life support ambulances. AEDs were applied to arrested patients by first-arriving personnel, whether police or paramedics. Data were obtained from PC Data Cards within the AED. Defibrillation was defined as at least transient termination of VF. Ten patients, 64 +/- 14 years, were treated for VF with BTE shocks. Another 8 patients were in nonshockable rhythms and the AEDs, appropriately, did not advise a shock. Five of the 10 VF arrests were witnessed with a 911 call-to-shock time of 6.6 +/- 1.7 minutes. VF detection and defibrillation occurred in all 10 patients. Spontaneous circulation was restored in 3 of 5 witnessed arrest patients and 1 survived to discharge home. Fifty-one VF episodes were converted with 62 shocks. Presenting VF amplitude and rate were 0.43 +/- 0.22 (0.13-0.86) mV and 232 +/- 62 (122-353) beats/min, respectively, and defibrillation was achieved with the first shock in 7 of 10 patients. Including transient conversions, defibrillation occurred in 42 of 51 VF episodes (82%) with one BTE shock. Shock impedance was 85 +/- 10 (39-138) ohms. Delivered energy and peak voltage were 152 +/- 2 J and 1754 +/- 4 V, respectively. The average number of shocks per VF episode was 1.2 +/- 0.5 (1-3). More than one shock was needed in only 9 episodes; none required > 3 shocks to defibrillate. Impedance-compensating low-energy BTE waveforms terminated VF in OHCA patients

  19. Outcomes of single- or dual-chamber implantable cardioverter defibrillator systems in Japanese patients

    PubMed Central

    Ueda, Akiko; Oginosawa, Yasushi; Soejima, Kyoko; Abe, Haruhiko; Kohno, Ritsuko; Ohe, Hisaharu; Momose, Yuichi; Nagaoka, Mika; Matsushita, Noriko; Hoshida, Kyoko; Miwa, Yosuke; Miyakoshi, Mutsumi; Togashi, Ikuko; Maeda, Akiko; Sato, Toshiaki; Yoshino, Hideaki

    2015-01-01

    Background There are no criteria for selecting single- or dual-chamber implantable cardioverter defibrillators (ICDs) in patients without a pacing indication. Recent reports showed no benefit of the dual-chamber system despite its preference in the United States. As data on ICD selection and respective outcomes in Japanese patients are scarce, we investigated trends regarding single- and dual-chamber ICD usage in Japan. Methods Data from a total of 205 ICD recipients with structural heart disease (median age, 63 years) in two Japanese university hospitals were reviewed. Patients with bradycardia with a pacing indication and permanent atrial fibrillation at implantation were excluded. Results Single- and dual-chamber ICDs were implanted in 36 (18%) and 169 (82%) patients, respectively. Non-ischemic cardiomyopathy dominated both groups. Seventeen dual-chamber patients developed atrial pacing-dependency over 4.5 years, and it developed immediately after implantation in 14. Although preoperative testing showed no sign of bradycardia in these patients, their pacing rate was set higher than it was in patients who were pacing-independent (61 vs. 46 paces per min, p<0.01). Two single-chamber patients (5%) underwent atrial lead insertion. While inappropriate shock equally occurred in both groups (7 vs. 21 patients, single- vs. dual-chamber, P=0.285), device-related infection occurred only in dual-chamber patients (0 vs. 9 patients, P=0.155). No differences in death or heart failure hospitalization were observed between groups. Conclusions Dual-chamber ICDs were four-fold more common in Japanese patients without a pacing indication. No benefit over single-chamber ICD was observed. Newly developed atrial pacing-dependency seemed to be limited and could have been overestimated due to higher pacing rate settings in dual-chamber patients. PMID:27092188

  20. Implantable Cardioverter Defibrillators in Octogenarians: Clinical Outcomes From a Single Center

    PubMed Central

    Wilson, D.G.; Ahmed, N.; Nolan, R.; Frontera, A.; Thomas, G.; Duncan, E.R.

    2016-01-01

    Aims Limited data exist on outcomes in very elderly ICD recipients. We describe outcomes in new ICD and Cardiac Resynchronisation Therapy with Defibrillator (CRT-D) implants in octogenarians at our institution. Methods Patients aged 80 years and above who underwent de novo ICD or CRT-D implantation from January 2006 to July 2012 were identified. Clinical data were collected from the procedural record, medical and ICD notes. Baseline characteristics were compared using independent sample t test for continuous variables and Fisher’s exact test for categorical variables. Kaplan-Meier curves were constructed. Results Ten per cent of all new ICD/CRT-D implants were aged 80 years and over. Median age was 83.0 years. Median follow-up was 29 months. Death occurred in 17 (34%). Median time to death was 23 months. Three deaths (6%) occurred within 12 months of ICD implantation. Appropriate therapy (ATP or shock) occurred in 19 (38%). Inappropriate therapy occurred in 6 (12%). Rates of appropriate shocks and inappropriate therapy (shocks and ATP) and significant valvular incompetence were higher amongst deceased patients (P=0.03 OR 5.9 95% CI 1.3-27) and (P=0.02 OR 12 95% CI 1.3-112). Univariate analysis identified diuretic use (P=0.008 95% C.I. 0.05 to 0.63) and appropriate shock (P= 0.025 95% C.I. 1.25 to 26.3) as predictors of mortality. Conclusion Octogenarians make up a small but increasing number of ICD recipients. This study highlights high survival rates at one year with acceptable rates of appropriate and inappropriate device therapy. Ongoing debate regarding the appropriateness of ICD in very elderly patients is warranted. PMID:25852237

  1. Disease management: remote monitoring in heart failure patients with implantable defibrillators, resynchronization devices, and haemodynamic monitors.

    PubMed

    Abraham, William T

    2013-06-01

    Heart failure represents a major public health concern, associated with high rates of morbidity and mortality. A particular focus of contemporary heart failure management is reduction of hospital admission and readmission rates. While optimal medical therapy favourably impacts the natural history of the disease, devices such as cardiac resynchronization therapy devices and implantable cardioverter defibrillators have added incremental value in improving heart failure outcomes. These devices also enable remote patient monitoring via device-based diagnostics. Device-based measurement of physiological parameters, such as intrathoracic impedance and heart rate variability, provide a means to assess risk of worsening heart failure and the possibility of future hospitalization. Beyond this capability, implantable haemodynamic monitors have the potential to direct day-to-day management of heart failure patients to significantly reduce hospitalization rates. The use of a pulmonary artery pressure measurement system has been shown to significantly reduce the risk of heart failure hospitalization in a large randomized controlled study, the CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III Heart Failure Patients (CHAMPION) trial. Observations from a pilot study also support the potential use of a left atrial pressure monitoring system and physician-directed patient self-management paradigm; these observations are under further investigation in the ongoing LAPTOP-HF trial. All these devices depend upon high-intensity remote monitoring for successful detection of parameter deviations and for directing and following therapy.

  2. Cost-effectiveness of Implantable Cardioverter-Defibrillators in Children with Dilated Cardiomyopathy

    PubMed Central

    Feingold, Brian; Arora, Gaurav; Webber, Steven A.; Smith, Kenneth J.

    2010-01-01

    Background Implantable cardioverter-defibrillators (ICDs) improve survival and are cost-effective in adults with poor left ventricular function. Because of differences in heart failure etiology, sudden death rates, and ICD complication rates, these findings may not be applicable to children. Methods and Results We developed a Markov model to compare typical management of childhood dilated cardiomyopathy with symptomatic heart failure to prophylactic ICD implantation plus typical management. Model costs included costs of outpatient care, medications, complications, and transplantation. Time horizon was up to 20 years from model entry. Total costs were $433,000 (ICD strategy) and $355,000 (typical management). Although quality adjusted survival was greater in the ICD group (6.78 vs. 6.43 quality adjusted life-years, QALYs), the incremental cost-utility ratio was $281,622/QALY saved with the ICD strategy. In sensitivity analyses, the ICD strategy cost less than the $100,000/QALY benchmark for cost-effectiveness only when the annual probability of sudden death exceeded 13% or when strong, sustained benefits in QOL due to the ICD were assumed. Conclusions Prophylactic ICD use in children with dilated cardiomyopathy, poor ventricular function, and symptomatic heart failure does not appear to be cost-effective. This is likely due to lower sudden death rates in this population. PMID:20797597

  3. Indications for implantable cardioverter-defibrillators based on evidence and judgment.

    PubMed

    Myerburg, Robert J; Reddy, Vivek; Castellanos, Agustin

    2009-08-25

    Implantable cardioverter-defibrillators (ICDs) are generally reliable medical devices that have the potential to add quality years of life for appropriate candidates. Indications for ICDs have emerged from a series of randomized clinical trials, observational data from cohorts of high-risk patients with less common diseases, and expert opinion based on limited data in uncommon disorders. The randomized trials are limited by inadequate stratification designs that resulted from insufficient funding availability. The result was outcomes that led to uneven applications, based in part on post-implant experience of device utilization. In this document, we explore the basis for the features of the evidence available to support ICD use, the role of clinical judgment in circumstances in which data are limited or lacking, and the need for additional research to improve the specificity of indications. Directions for new research initiatives are considered. In addition, a general overview of a clinical research paradigm is presented, in which the research and health care delivery arms of the health care enterprise combine in research design and funding, as the latter bears the impact of the outcomes of the former. Impact estimates during the design of trials, considering reasonable contingencies for outcomes, are suggested as a means of justifying the size, scope, and appropriate costs of studies. If we who are involved in clinical research and health care delivery do not resolve this problem, for both ICDs and other new therapies that appear in the future, society will do it for us.

  4. A new single chamber implantable defibrillator with atrial sensing: a practical demonstration of sensing and ease of implantation.

    PubMed

    Bänsch, Dietmar; Schneider, Ralph; Akin, Ibrahim; Nienaber, Cristoph A

    2012-02-28

    Implantable cardioverter-defibrillators (ICDs) terminate ventricular tachycardia (VT) and ventricular fibrillation (VF) with high efficacy and can protect patients from sudden cardiac death (SCD). However, inappropriate shocks may occur if tachycardias are misdiagnosed. Inappropriate shocks are harmful and impair patient quality of life. The risk of inappropriate therapy increases with lower detection rates programmed in the ICD. Single-chamber detection poses greater risks for misdiagnosis when compared with dual-chamber devices that have the benefit of additional atrial information. However, using a dual-chamber device merely for the sake of detection is generally not accepted, since the risks associated with the second electrode may outweigh the benefits of detection. Therefore, BIOTRONIK developed a ventricular lead called the Linox(SMART) S DX, which allows for the detection of atrial signals from two electrodes positioned at the atrial part of the ventricular electrode. This device contains two ring electrodes; one that contacts the atrial wall at the junction of the superior vena cava (SVC) and one positioned at the free floating part of the electrode in the atrium. The excellent signal quality can only be achieved by a special filter setting in the ICD (Lumax 540 and 740 VR-T DX, BIOTRONIK). Here, the ease of implantation of the system will be demonstrated.

  5. Longitudinal changes in intracardiac repolarization lability in patients with implantable cardioverter-defibrillator

    PubMed Central

    Guduru, Abhilash; Lansdown, Jason; Chernichenko, Daniil; Berger, Ronald D.; Tereshchenko, Larisa G.

    2013-01-01

    Background: While it is known that elevated baseline intracardiac repolarization lability is associated with the risk of fast ventricular tachycardia (FVT)/ventricular fibrillation (VF), the effect of its longitudinal changes on the risk of FVT/VF is unknown. Methods and Results: Near-field (NF) right ventricular (RV) intracardiac electrograms (EGMs) were recorded every 3–6 months at rest in 248 patients with structural heart disease [mean age 61.2 ± 13.3; 185(75%) male; 162(65.3%) ischemic cardiomyopathy] and implanted cardioverter-defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D) [201 (81%) primary prevention]. Intracardiac beat-to-beat QT variability index (QTVINF) was measured on NF RV EGM. During the first study phase (median 18 months), participants made on average 2.4 visits. Then remote follow-up was continued for an additional median period of 3 years. Average QTVINF did not change during the first year after ICD implantation (−0.342 ± 0.603 at baseline vs. −0.262 ± 0.552 at 6 months vs. −0.334 ± 0.603 at 12 months); however, it decreased thereafter (−0.510 ± 0.603 at 18 months; P = 0.042). Adjusted population-averaged GEE model showed that the odds of developing FVT/VF increased by 75% for each 1 unit increase in QTVINF. (OR 1.75 [95%CI 1.05–2.92]; P = 0.031). However, individual patient–specific QTVINF trends (increasing, decreasing, flat) varied from patient to patient. For a given patient, the odds of developing FVT/VF were not associated with increasing or decreasing QTVINF over time [OR 1.27; (95%CI 0.05–30.10); P = 0.881]. Conclusion: While on average the odds of FVT/VF increased with an increase in QTVINF, patient-specific longitudinal trends in QTVINF did not affect the odds of FVT/VF. PMID:23964242

  6. Psychological effects of implantable cardioverter defibrillator shocks. A review of study methods

    PubMed Central

    Manzoni, Gian Mauro; Castelnuovo, Gianluca; Compare, Angelo; Pagnini, Francesco; Essebag, Vidal; Proietti, Riccardo

    2015-01-01

    Background: The implantable cardioverter defibrillator (ICD) saves lives but clinical experience suggests that it may have detrimental effects on mental health. The ICD shock has been largely blamed as the main offender but empirical evidence is not consistent, perhaps because of methodological differences across studies. Objective: To appraise methodologies of studies that assessed the psychological effects of ICD shock and explore associations between methods and results. Data Sources: A comprehensive search of English articles that were published between 1980 and 30 June 2013 was applied to the following electronic databases: PubMed, EMBASE, NHS HTA database, PsycINFO, Sciencedirect and CINAHL. Review Methods: Only studies testing the effects of ICD shock on psychological and quality of life outcomes were included. Data were extracted according to a PICOS pre-defined sheet including methods and study quality indicators. Results: Fifty-four observational studies and six randomized controlled trials met the inclusion criteria. Multiple differences in methods that were used to test the psychological effects of ICD shock were found across them. No significant association with results was observed. Conclusions: Methodological heterogeneity of study methods is too wide and limits any quantitative attempt to account for the mixed findings. Well-built and standardized research is urgently needed. PMID:25698991

  7. Interference of neodymium magnets with cardiac pacemakers and implantable cardioverter-defibrillators: an in vitro study.

    PubMed

    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.

  8. Arrhythmia Management in the Elderly-Implanted Cardioverter Defibrillators and Prevention of Sudden Death.

    PubMed

    Manian, Usha; Gula, Lorne J

    2016-09-01

    We present an overview of arrhythmia management in elderly patients as it pertains to implantable cardioverter defibrillator (ICD) therapy and prevention of sudden death. Treatment of arrhythmia in elderly patients is fraught with challenges pertaining to goals of care and patient frailty. With an ever increasing amount of technology available, realistic expectations of therapy need to balance quality and quantity of life. The ICD is an important treatment option for selected patients at risk of ventricular arrhythmia and sudden cardiac death. However, the incidence of sudden death as a percentage of all-cause mortality decreases with age. Studies have reported that 20% of elderly patients might die within 1 year of an episode of life-threatening ventricular arrhythmia, but most because of nonarrhythmic causes. This illustrates the 'sudden cardiac death paradox,' with a great proportion of death in elderly patients, even those at risk for ventricular arrhythmias, attributable to medical conditions that cannot be addressed by an ICD. We discuss current practices in ICD therapy in elderly patients, existing evidence from registries and clinical trials, approaches to risk stratification, and important ethical considerations. Although the decision on whether ICD insertion is appropriate in the elderly population remains an area of uncertainty from an evidence-based and ethical perspective, we offer insight on potential clinical and research strategies for this growing population.

  9. Magnetic resonance imaging safety in pacemaker and implantable cardioverter defibrillator patients: how far have we come?

    PubMed Central

    Nordbeck, Peter; Ertl, Georg; Ritter, Oliver

    2015-01-01

    Magnetic resonance imaging (MRI) has long been regarded a general contraindication in patients with cardiovascular implanted electronic devices such as cardiac pacemakers or cardioverter defibrillators (ICDs) due to the risk of severe complications and even deaths caused by interactions of the magnetic resonance (MR) surrounding and the electric devices. Over the last decade, a better understanding of the underlying mechanisms responsible for such potentially life-threatening complications as well as technical advances have allowed an increasing number of pacemaker and ICD patients to safely undergo MRI. This review lists the key findings from basic research and clinical trials over the last 20 years, and discusses the impact on current day clinical practice. With ‘MR-conditional’ devices being the new standard of care, MRI in pacemaker and ICD patients has been adopted to clinical routine today. However, specific precautions and specifications of these devices should be carefully followed if possible, to avoid patient risks which might appear with new MR technology and further increasing indications and patient numbers. PMID:25796053

  10. Implantable Heart Aid

    NASA Technical Reports Server (NTRS)

    1984-01-01

    CPI's human-implantable automatic implantable defibrillator (AID) is a heart assist system, derived from NASA's space circuitry technology, that can prevent erratic heart action known as arrhythmias. Implanted AID, consisting of microcomputer power source and two electrodes for sensing heart activity, recognizes onset of ventricular fibrillation (VF) and delivers corrective electrical countershock to restore rhythmic heartbeat.

  11. Induction ovens and electromagnetic interference: what is the risk for patients with implantable cardioverter defibrillators?

    PubMed

    Binggeli, Christian; Rickli, Hans; Ammann, Peter; Brunckhorst, Corinna; Hufschmid, Urs; Luechinger, Roger; Duru, Firat

    2005-04-01

    Electromagnetic fields may interfere with normal implantable cardioverter defibrillator (ICD) function. Although the devices are effectively shielded and use exclusively bipolar leads, electromagnetic interference (EMI) remains a concern when patients are exposed to several household appliances. The aim of this study was to evaluate potential EMI risk of induction ovens, which are increasingly common in private households. In vitro measurements of an induction oven for private households GK 43 TI (V-Zug, Inc., Zug, Switzerland) showed that heating is regulated by increasing operating time from level 1 (100 ms/sec) to 5 (continuous operation). From levels 5 to 9 the magnetic field increases. Nineteen patients with left-sided implants of single- and dual-chamber ICD systems (8 Medtronic, 7 Guidant, and 4 St. Jude Medical) (18 males, 1 female), age (mean +/- SEM) 58 +/- 3 years, were included in this study. All patients were examined in standing position, bent over the cooking pot (minimal distance to the induction coil 25 cm), and with the cooking pot put eccentrically over the induction field at three different cooking levels (level 2, 5, and 9). The tests were repeated touching the cooking pot with one hand. Ventricular sensitivity was left unchanged. Ventricular tachycardia therapies were turned off in Medtronic and Guidant devices and ventricular sensing was continuously monitored in St. Jude Medical devices during testing. Interrogation of the devices after exposure did not show any inappropriate tachycardia detection, oversensing, or reprogramming. In conclusion, ICD patients can be reassured that EMI is unlikely to affect their devices if induction ovens are used in their kitchens.

  12. Current Indications for Implantable Cardioverter Defibrillators in Non-Ischemic Cardiomyopathies and Channelopathies.

    PubMed

    González-Torrecilla, Esteban; Arenal, Angel; Atienza, Felipe; Datino, Tomás; Bravo, Loreto; Ruiz, Pablo; Ávila, Pablo; Fernández-Avilés, Francisco

    2015-01-01

    Current indications for implantable cardioverter defibrillators (ICDs) in patients with channelopathies and cardiomyopathies of non-ischemic origin are mainly based on non-randomized evidence. In patients with nonischemic dilated cardiomyopathy (NIDCM), there is a tendency towards a beneficial effect on total mortality of ICD therapy in patients with significant left ventricular (LV) dysfunction. Although an important reduction in sudden cardiac death (SCD) seems to be clearly demonstrated in these patients, a net beneficial effect on total mortality is unclear mostly in cases with good functional status. Risk stratification has been changing over the last two decades in patients with hypertrophic cardiomyopathy (HCM). Its risk profile has been delineated in parallel with the beneficial effect of ICD in high risk patients. Observational results based on "appropriate" ICD interventions do support its usefulness both in primary and secondary SCD prevention in these patients. Novel risk models quantify the rate of sudden cardiac death in these patients on individual basis. Less clear risk stratification is available for cases of arrhythmogenic right ventricular cardiomyopathy (ARVC) and in other uncommon familiar cardiomyopathies. Main features of risk stratification vary among the different channelopathies (long QT syndrome -LQTS-, Brugada syndrome, etc) with great debate on the management of asymptomatic patients. For most familiar cardiomyopathies, ICD therapy is the only accepted strategy in the prevention of SCD. So far, genetic testing has a limited role in risk evaluation and management of the individual patient. This review aims to summarize these criticisms and to refine the current indications of ICD implantation in patients with cardiomyopathies and major channelopathies.

  13. Utilization and likelihood of radiologic diagnostic imaging in patients with implantable cardiac defibrillators

    PubMed Central

    Reynolds, Matthew R.; Ryan, Michael P.; Wolff, Steven D.; Mollenkopf, Sarah A.; Turakhia, Mintu P.

    2015-01-01

    Purpose To examine imaging utilization in a matched cohort of patients with and without implantable cardioverter defibrillators (ICD) and to project magnetic resonance imaging (MRI) utilization over a 10‐year period. Materials and Methods The Truven Health MarketScan Commercial claims and Medicare Supplemental health insurance claims data were used to identify patients with continuous health plan enrollment in 2009–2012. Patients with ICDs were identified using ICD‐9 and CPT codes, and matched to patients with the same demographic and comorbidity profile, but no record of device implantation. Diagnostic imaging utilization was compared across the matched cohorts, in total, by imaging categories, and in subpopulations of stroke, back pain, and joint pain. MRI use in the nonimplant group over the 4‐year period was extrapolated out to 10 years for ICD‐indicated patients. Results A cohort of 18,770 matched patients were identified; average age 65.5 ± 13.38 and 21.9% female. ICD patients had significantly less MRI imaging (0.23 0.70 SD vs. 0.00 0.08 SD, P < 0.0001) than nonimplant patients. Among patients with records of stroke/transient ischemic attack (TIA) (ICD 5%, nonimplant 4%) and accompanying diagnostic imaging, 44% of nonimplant patients underwent MRI vs. 1% of ICD patients (P < 0.0001). Forecast models estimated that 53% to 64% of ICD‐eligible patients may require an MRI within 10 years. Conclusion MRI utilization is lower in ICD patients compared to nonimplant patients, yet the burden of incident stroke/TIA, back, and joint pain suggests an unmet need for MR‐conditional devices. J. MAGN. RESON. IMAGING 2016;43:115–127. PMID:26118943

  14. Influence of radiotherapy on the latest generation of implantable cardioverter-defibrillators

    SciTech Connect

    Hurkmans, Coen W. . E-mail: Coen.Hurkmans@cze.nl; Scheepers, Egon; Springorum, Bob G.F.; Uiterwaal, Hans

    2005-09-01

    Purpose: Radiotherapy can influence the functioning of pacemakers and implantable cardioverter-defibrillators (ICDs). ICDs offer the same functionality as pacemakers, but are also able to deliver a high-voltage shock to the heart if needed. Guidelines for radiotherapy treatment of patients with an implanted rhythm device have been published in 1994 by The American Association of Physicists in Medicine, and are based only on experience with pacemakers. Data on the influence of radiotherapy on ICDs are limited. The objective of our study is to determine the influence of radiotherapy on the latest generation of ICDs. Methods and Materials: Eleven modern ICDs have been irradiated in our department. The irradiation was performed with a 6-MV photon beam. The given dose was fractionated up to a cumulative dose of 120 Gy. Two to 5 days passed between consecutive irradiations. Frequency, output, sensing, telemetry, and shock energy were monitored. Results: Sensing interference by ionizing radiation on all ICDs has been demonstrated. For four ICDs, this would have caused the inappropriate delivery of a shock because of interference. At the end of the irradiation sessions, all devices had reached their point of failure. Complete loss of function was observed for four ICDs at dose levels between 0.5 Gy and 1.5 Gy. Conclusions: The effect of radiation therapy on the newest generation of ICDs varies widely. If tachycardia monitoring and therapy are functional (programmed on) during irradiation, the ICD might inappropriately give antitachycardia therapy, often resulting in a shock. Although most ICDs did not fail below 80 Gy, some devices had already failed at doses below 1.5 Gy. Guidelines are formulated for the treatment of patients with an ICD.

  15. [Therapy with implantable cardioverter-defibrillators (ICD) in the early of third millenium].

    PubMed

    Kozák, M

    2010-08-01

    The patients without ventricular arrhythmias with markers of high risk of sudden cardiac death are indicated for ICD implantation today. Last generation of ICD systems are equipped with high capacity batteries, with many automatic functions, capabilities of data sending and possibilities of prediction of worsening of heart failure. Nowadays ICD systems offers not only elimination of the risk of sudden cardiac death but reduction of symptoms of chronic heart failure through the resynchronization therapy, too.

  16. Gender and outcomes after primary prevention implantable cardioverter-defibrillator implantation: Findings from the National Cardiovascular Data Registry (NCDR)

    PubMed Central

    Russo, Andrea M.; Daugherty, Stacie L.; Masoudi, Frederick A.; Wang, Yongfei; Curtis, Jeptha; Lampert, Rachel

    2016-01-01

    Background Clinical trials have demonstrated the benefit of implantable cardioverter-defibrillators (ICDs) for the primary prevention of sudden cardiac death in selected high-risk individuals. Because of small numbers of women enrolled in these trials, outcomes for women after hospital discharge have not been well described. We compared procedure-related complications and outcomes after hospital discharge between men and women undergoing single- or dual-chamber ICD implantation for primary prevention. Methods In patients 65 years or older with Medicare fee-for-service coverage, we identified 38,912 initial implants (25% women) who received single- or dual-chamber ICDs for primary prevention between January 2006 and December 2009 in the NCDR and evaluated gender differences in outcomes. Results Women had greater comorbidity and more advanced heart failure (HF) at the time of ICD implantation than did men. Device-related complications, death at 6 months, all-cause readmissions, and HF readmissions at 6 months were significantly more common in women (7.2% vs 4.8%, 6.5% vs 5.6%, 37.2% vs 31.7%, and 14.0% vs 10.0% respectively; P < .001 for all). Women continued to have higher odds of procedural complications (odds ratio [OR] 1.39, 95% CI 1.26–1.53, P < .001), 6-month all-cause readmission (OR 1.22, 95% CI 1.16–1.28, P < .001), and 6-month HF readmission (OR 1.32, 95% CI 1.23–1.42, P < .001), with a trend toward higher 6-month mortality (OR 1.08, 95% CI 0.98–1.20, P = .123), compared with men, after adjusting for differences in baseline characteristics and device type (single vs dual chamber). Conclusions Among older patients receiving ICDs for primary prevention in clinical practice, women experience worse outcomes than do men. Reasons for gender differences in outcomes are poorly understood and require further investigation. PMID:26299231

  17. Implantation of a right ventricular implantable cardioverter-defibrillator lead in the right ventricular outflow tract in a patient with Ebstein anomaly and right ventricular lead dislocation.

    PubMed

    Pecha, Simon; Yildirim, Yalin; Hahnel, Fabian; Reichenspurner, Hermann; Aydin, Muhammed Ali

    2014-04-01

    An 80-year-old patient with Ebstein anomaly and prior implantable cardioverter-defibrillator (ICD) implantation was sent to our heart center because of right ventricular (RV)-ICD lead dislocation. Positioning of the new RV lead was difficult, no stable position could be found, and sensing and threshold measurements showed weak results in the RV basis, apex, and septum. So, we conducted positioning of the lead in the RV outflow tract where a stable position with good sensing and threshold parameters was found.

  18. Analysis of willingness to pay for implantable cardioverter-defibrillator therapy.

    PubMed

    Nowakowska, Dominika; Guertin, Jason R; Liu, Aihua; Abrahamowicz, Michal; Lelorier, Jacques; Lespérance, François; Brophy, James M; Rinfret, Stéphane

    2011-02-01

    Despite being effective in the primary and secondary prevention of sudden cardiac arrest, the cost-effectiveness of implantable cardioverter-defibrillator (ICD) therapy remains debated. We attempted to estimate the value ICD recipients place on their ICD device. We used the contingent valuation method to evaluate the willingness to pay (WTP) and the cost benefit of ICD therapy in an unselected population of 237 recipients. A hypothetical scenario was presented to patients in which at the end of their current ICD no public reimbursement for the replacement would occur. Patients were asked to indicate their out-of-pocket WTP for a replacement ICD using a close-ended question format. Seven different "take-it-or-leave-it" bids were randomly varied and assigned to patients. Median WTP was calculated with nonparametric methods, and multiple logistic regression models were generated to identify factors associated with WTP. Only cost of the device was considered. Median WTP was estimated at CAN $4,125, which corresponds to 21% of the cost of the device (CAN $20,000). In multiple logistic regression analysis, a higher bid (odds ratio [OR] 0.95, 95% confidence interval [CI] 0.91 to 0.99, per CAN $1,000 increase) was associated with a lower WTP, whereas a higher gross family income (OR 2.3, 95% CI 0.9 to 9.0) and higher education (OR 2.2, 95% CI 0.9 to 5.1) were associated with a trend for higher WTP. In conclusion, ICD recipients would be willing to pay a substantial amount for a replacement ICD. Considering the expensive price of the device, ICD recipients value favorably the benefits provided by the ICD.

  19. Sustaining cyborgs: sensing and tuning agencies of pacemakers and implantable cardioverter defibrillators.

    PubMed

    Oudshoorn, Nelly

    2015-02-01

    Recently there has been a renewed interest in cyborgs, and particularly in new and emerging fusions of humans and technologies related to the development of human enhancement technologies. These studies reflect a trend to follow new and emerging technologies. In this article, I argue that it is important to study 'older' and more familiar cyborgs as well. Studying 'the old' is important because it enables us to recognize hybrids' embodied experiences. This article addresses two of these older hybrids: pacemakers and implantable cardioverter defibrillators inserted in the bodies of people suffering from heart-rhythm disturbances. My concern with hybrid bodies is that internal devices seem to present a complex and neglected case if we wish to understand human agency. Their 'users' seem to be passive because they cannot exert any direct control over the working of their devices. Technologies inside bodies challenge a longstanding tradition of theorizing human-technology relations only in terms of technologies external to the body. Cyborg theory is problematic as well because most studies tend to conceptualize the cyborg merely as a discursive entity and silence the voices of people living as cyborgs. Inspired by feminist research that foregrounds the materiality of the lived and intimate relations between bodies and technologies, I argue that creating these intimate relations requires patients' active involvement in sustaining their hybrid bodies. Based on observations of these monitoring practices in a Dutch hospital and interviews with patients and technicians, the article shows that heart cyborgs are far from passive. On the contrary, their unique experience in sensing the entangled agencies of technologies and their own heart plays a crucial role in sustaining their hybrid bodies.

  20. BAYESIAN META-ANALYSIS ON MEDICAL DEVICES: APPLICATION TO IMPLANTABLE CARDIOVERTER DEFIBRILLATORS

    PubMed Central

    Youn, Ji-Hee; Lord, Joanne; Hemming, Karla; Girling, Alan; Buxton, Martin

    2012-01-01

    Objectives: The aim of this study is to describe and illustrate a method to obtain early estimates of the effectiveness of a new version of a medical device. Methods: In the absence of empirical data, expert opinion may be elicited on the expected difference between the conventional and modified devices. Bayesian Mixed Treatment Comparison (MTC) meta-analysis can then be used to combine this expert opinion with existing trial data on earlier versions of the device. We illustrate this approach for a new four-pole implantable cardioverter defibrillator (ICD) compared with conventional ICDs, Class III anti-arrhythmic drugs, and conventional drug therapy for the prevention of sudden cardiac death in high risk patients. Existing RCTs were identified from a published systematic review, and we elicited opinion on the difference between four-pole and conventional ICDs from experts recruited at a cardiology conference. Results: Twelve randomized controlled trials were identified. Seven experts provided valid probability distributions for the new ICDs compared with current devices. The MTC model resulted in estimated relative risks of mortality of 0.74 (0.60–0.89) (predictive relative risk [RR] = 0.77 [0.41–1.26]) and 0.83 (0.70–0.97) (predictive RR = 0.84 [0.55–1.22]) with the new ICD therapy compared to Class III anti-arrhythmic drug therapy and conventional drug therapy, respectively. These results showed negligible differences from the preliminary results for the existing ICDs. Conclusions: The proposed method incorporating expert opinion to adjust for a modification made to an existing device may play a useful role in assisting decision makers to make early informed judgments on the effectiveness of frequently modified healthcare technologies. PMID:22559753

  1. A Prospective Randomized Trial of Moderately Strenuous Aerobic Exercise After an Implantable Cardioverter Defibrillator (ICD)

    PubMed Central

    Dougherty, Cynthia M.; Glenny, Robb W.; Burr, Robert L.; Flo ARNP, Gayle L.; Kudenchuk, Peter J.

    2015-01-01

    Background Despite its salutary effects on health, aerobic exercise is often avoided after receipt of an implantable cardioverter-defibrillator (ICD) because of fears that exercise may provoke acute arrhythmias. We prospectively evaluated the effects of a home aerobic exercise training and maintenance program (EX) on aerobic performance, ICD shocks and hospitalizations exclusively in ICD recipients. Methods and Results One hundred sixty (124 men, 36 women) were randomized who had an ICD for primary (43%) or secondary (57%) prevention to EX or usual care (UC). The primary outcome was peak oxygen consumption (peakVO2), measured with cardiopulmonary exercise testing at baseline, 8 and 24 weeks. EX consisted of 8 weeks of home walking 1 hour/day, 5 days/week at 60-80% of heart rate reserve, followed by 16 weeks of maintenance home walking for 150 minutes/week. Adherence to EX was determined from exercise logs, ambulatory HR recordings of exercise, and weekly telephone contacts. UC received no exercise directives and were monitored by monthly telephone contact. Adverse events were identified by ICD interrogations, patient reports and medical records. ICD recipients averaged 55±12 years and mean ejection fraction of 40.6±15.7, all were taking beta blocker medications. EX significantly increased peakVO2 ml/kg/min (EX 26.7±7.0; UC 23.9±6.6, p=0.002) at 8 weeks, which persisted during maintenance exercise at 24 weeks (EX 26.9±7,7; UC 23.4±6.0, p<0.001). ICD shocks were infrequent (EX=4 vs UC=8), with no differences in hospitalizations or deaths between groups. Conclusions Prescribed home exercise is safe and significantly improves cardiovascular performance in ICD recipients without causing shocks or hospitalizations. PMID:25792557

  2. Performance of 2014 NICE defibrillator implantation guidelines in heart failure risk stratification

    PubMed Central

    Cubbon, Richard M; Witte, Klaus K; Kearney, Lorraine C; Gierula, John; Byrom, Rowenna; Paton, Maria; Sengupta, Anshuman; Patel, Peysh A; MN Walker, Andrew; Cairns, David A; Rajwani, Adil; Hall, Alistair S; Sapsford, Robert J; Kearney, Mark T

    2016-01-01

    Objective Define the real-world performance of recently updated National Institute for Health and Care Excellence guidelines (TA314) on implantable cardioverter-defibrillator (ICD) use in people with chronic heart failure. Methods Multicentre prospective cohort study of 1026 patients with stable chronic heart failure, associated with left ventricular ejection fraction (LVEF) ≤45% recruited in cardiology outpatient departments of four UK hospitals. We assessed the capacity of TA314 to identify patients at increased risk of sudden cardiac death (SCD) or appropriate ICD shock. Results The overall risk of SCD or appropriate ICD shock was 2.1 events per 100 patient-years (95% CI 1.7 to 2.6). Patients meeting TA314 ICD criteria (31.1%) were 2.5-fold (95% CI 1.6 to 3.9) more likely to suffer SCD or appropriate ICD shock; they were also 1.5-fold (95% CI 1.1 to 2.2) more likely to die from non-cardiovascular causes and 1.6-fold (95% CI 1.1 to 2.3) more likely to die from progressive heart failure. Patients with diabetes not meeting TA314 criteria experienced comparable absolute risk of SCD or appropriate ICD shock to patients without diabetes who met TA314 criteria. Patients with ischaemic cardiomyopathy not meeting TA314 criteria experienced comparable absolute risk of SCD or appropriate ICD shock to patients with non-ischaemic cardiomyopathy who met TA314 criteria. Conclusions TA314 can identify patients with reduced LVEF who are at increased relative risk of sudden death. Clinicians should also consider clinical context and the absolute risk of SCD when advising patients about the potential risks and benefits of ICD therapy. PMID:26857212

  3. Patient barriers to implantable cardioverter defibrillator implantation for the primary prevention of sudden cardiac death in patients with heart failure and reduced ejection fraction

    PubMed Central

    Chan, Laura Lihua; Lim, Choon Pin; Aung, Soe Tin; Quetua, Paul; Ho, Kah Leng; Chong, Daniel; Teo, Wee Siong; Sim, David; Ching, Chi Keong

    2016-01-01

    INTRODUCTION Device therapy is efficacious in preventing sudden cardiac death (SCD) in patients with reduced ejection fraction. However, few who need the device eventually opt to undergo implantation and even fewer reconsider their decisions after deliberation. This is due to many factors, including unresolved patient barriers. This study identified the factors that influenced patients’ decision to decline implantable cardioverter defibrillator (ICD) implantation, and those that influenced patients who initially declined an implant to reconsider having one. METHODS A single-centre survey was conducted among 240 patients who had heart failure with reduced ejection fraction and met the ICD implantation criteria, but had declined ICD implantation. RESULTS Participants who refused ICD implantation were mostly male (84%), Chinese (71%), married (72%), currently employed (54%), and had up to primary or secondary education (78%) and monthly income of < SGD 3,000 (51%). Those who were more likely to reconsider their decision were aware that SCD was a consequence of heart failure with reduced ejection fraction, knowledgeable of the preventive role of ICDs, currently employed and aware that their doctor strongly recommended the implant. Based on multivariate analysis, knowledge of the role of ICDs for primary prophylaxis was the most important factor influencing patient decision. CONCLUSION This study identified the demographic and social factors of patients who refused ICD therapy. Knowledge of the role of ICDs in preventing SCD was found to be the strongest marker for reconsidering ICD implantation. Measures to address this information gap may lead to higher rates of ICD implantation. PMID:27075476

  4. [Pacemaker, implanted cardiac defibrillator and irradiation: Management proposal in 2010 depending on the type of cardiac stimulator and prognosis and location of cancer].

    PubMed

    Lambert, P; Da Costa, A; Marcy, P-Y; Kreps, S; Angellier, G; Marcié, S; Bondiau, P-Y; Briand-Amoros, C; Thariat, J

    2011-06-01

    Ionizing radiation may interfere with electric components of pacemakers or implantable cardioverter-defibrillators. The type, severity and extent of radiation damage to pacemakers, have previously been shown to depend on the total dose and dose rate. Over 300,000 new cancer cases are treated yearly in France, among which 60% are irradiated in the course of their disease. One among 400 of these patients has an implanted pacemaker or defibrillator. The incidence of pacemaker and implanted cardioverter defribillator increases in an ageing population. The oncologic prognosis must be weighted against the cardiologic prognosis in a multidisciplinary and transversal setting. Innovative irradiation techniques and technological sophistications of pacemakers and implantable cardioverter-defibrillators (with the introduction of more radiosensitive complementary metal-oxide-semiconductors since 1970) have potentially changed the tolerance profiles. This review of the literature studied the geometric, dosimetric and radiobiological characteristics of the radiation beams for high energy photons, stereotactic irradiation, protontherapy. Standardized protocols and radiotherapy optimization (particle, treatment fields, energy) are advisable in order to improve patient management during radiotherapy and prolonged monitoring is necessary following radiation therapy. The dose received at the pacemaker/heart should be calculated. The threshold for the cumulated dose to the pacemaker/implantable cardioverter-defibrillator (2 to 5 Gy depending on the brand), the necessity to remove/displace the device based on the dose-volume histogram on dosimetry, as well as the use of lead shielding and magnet are discussed.

  5. [From implantable cardioverter-defibrillator to cardiac resynchronization therapy with the use of epicardial left ventricular lead. The evolution of the treatment of post inflammatory heart failure--a case report].

    PubMed

    Gepner, Katarzyna; Sterliński, Maciej; Przybylski, Andrzej; Maciag, Aleksander; Kołsut, Piotr; Szwed, Hanna

    2006-10-01

    The authors present a case of a 77-year-old man with heart failure in the course of dilated cardiomyopathy (DCM) and atrial fibrillation (AF), after implantation of an automatic cardioverter-defibrillator (ICD) due to recurrent symptomatic ventricular tachycardia (VT). Addition of cardiac resynchronization therapy (CRT) was decided due to the heart-failure dependent intensification of the arrhythmia and poststimulation enlargement of QRS. CRT was led to withdraw patient's arrhythmia and to improvement of the general condition of the patient for approximately one year. After the arrhythmia reoccurred due to dislocation of the electrode in the coronary sinus with loss of left ventricle stimulation. Multiple attempts at restoration of resynchronization function via a transvenous approach failed. The patient was qualified for implantation of an epicardial left ventricle electrode. The surgery was combined with a planned exchange of ICD-CRT. Basing on a 6-month observation period an improvement heart performance and general state of health have been observed. No arrhythmic event has been noted in device memory. Performed procedures are picturing the evolution of in pacing techniques and automatic defibrillation in Poland over recent years.

  6. Physiotherapy as a Rare Cause of Twiddler’s Syndrome in a Patient With an Implanted Cardioverter Defibrillator

    PubMed Central

    Schernthaner, Christiana; Danmayr, Franz; Krausler, Richard; Strohmer, Bernhard

    2013-01-01

    A 65-year-old male patient with a history of ischemic cardiomyopathy developed ventricular tachycardia resulting in presyncope. An ICD was indicated for secondary prophylaxis of ventricular tachyarrhythmias. A dual chamber ICD was implanted from the right side because insertion of the device from the left side was unfeasible after surgery of a left subscapularis tendon lesion. ICD implantation and testing of defibrillation threshold were uneventful. During early follow-up a progressive increase of the stimulation threshold was detected. On chest X-ray coiling of both atrial and ventricular leads was noted and caused inadvertently by active shoulder-arm physiotherapy. Complete revision of the ICD system was necessary for restoration of the pacemaker function of the ICD. This unique case highlights important steps for early recognition and prevention of Twiddler’s syndrome that may occur due to physiotherapy treatment even without abnormal manipulations by the patient.

  7. Practical and ethical considerations in the management of pacemaker and implantable cardiac defibrillator devices in terminally ill patients

    PubMed Central

    Sorkness, Christine A.

    2017-01-01

    More than 4.5 million people worldwide live with an implanted pacemaker, including >3 million in the USA alone. Also, >0.8 million people in the USA have an implantable cardioverter defibrillator (ICD). Knowing the principles of managing these devices towards the end of life is important, as the interruption of their function may have serious consequences. This article provides health care providers who are not specialized in cardiac electrophysiology with an introduction to the general principles of management of pacemakers or ICD devices towards the end of life, with a suggested algorithm for approaching this process. Also discussed are pertinent ethical and practical considerations in deciding on and implementing a management strategy for these devices during terminal illnesses.

  8. Outcomes After Implantable Cardioverter-Defibrillator Generator Replacement for Primary Prevention of Sudden Cardiac Death

    PubMed Central

    Madhavan, Malini; Waks, Jonathan W.; Friedman, Paul A.; Kramer, Daniel B.; Buxton, Alfred E.; Noseworthy, Peter A.; Mehta, Ramila A.; Hodge, David O.; Higgins, Angela Y.; Webster, Tracy L.; Witt, Chance M.; Cha, Yong-Mei; Gersh, Bernard J.

    2016-01-01

    Background The effectiveness of implantable cardioverter-defibrillators (ICDs) for primary prevention of sudden death in patients with an ejection fraction (EF) ≤35% and clinical heart failure is well established. However, outcomes after replacement of the ICD generator in patients with recovery of EF to >35% and no previous therapies are not well characterized. Methods and Results Between 2001 and 2011, generator replacement was performed at 2 tertiary medical centers in 253 patients (mean age, 68.3±12.7 years; 82% men) who had previously undergone ICD placement for primary prevention but subsequently never received appropriate ICD therapy. EF had recovered to >35% in 72 of 253 (28%) patients at generator replacement. During median (quartiles) follow-up of 3.3 (1.8–5.3) years after generator replacement, 68 of 253 (27%) experienced appropriate ICD therapy. Patients with EF ≤35% were more likely to experience ICD therapy compared with those with EF >35% (12% versus 5% per year; hazard ratio, 3.57; P=0.001). On multivariable analysis, low EF predicted appropriate ICD therapy after generator replacement (hazard ratio, 1.96 [1.35–2.87] per 10% decrement; P=0.001). Death occurred in 25% of patients 5 years after generator replacement. Mortality was similar in patients with EF ≤35% and >35% (7% versus 5% per year; hazard ratio, 1.10; P=0.68). Atrial fibrillation (3.24 [1.63–6.43]; P<0.001) and higher blood urea nitrogen (1.28 [1.14–1.45] per increase of 10 mg/dL; P<0.001) were associated with mortality. Conclusions Although approximately one fourth of patients with a primary prevention ICD and no previous therapy have EF >35% at the time of generator replacement, these patients continue to be at significant risk for appropriate ICD therapy (5% per year). These data may inform decisions on ICD replacement. PMID:26921377

  9. Serum-Based Oxylipins Are Associated with Outcomes in Primary Prevention Implantable Cardioverter Defibrillator Patients

    PubMed Central

    Zhang, Yiyi; Guallar, Eliseo; Blasco-Colmenares, Elena; Harms, Amy C.; Vreeken, Rob J.; Hankemeier, Thomas; Tomaselli, Gordon F.; Cheng, Alan

    2016-01-01

    Introduction Individuals with systolic heart failure are at risk of ventricular arrhythmias and all-cause mortality. Little is known regarding the mechanisms underlying these events. We sought to better understand if oxylipins, a diverse class of lipid metabolites derived from the oxidation of polyunsaturated fatty acids, were associated with these outcomes in recipients of primary prevention implantable cardioverter defibrillators (ICDs). Methods Among 479 individuals from the PROSE-ICD study, baseline serum were analyzed and quantitatively profiled for 35 known biologically relevant oxylipin metabolites. Associations with ICD shocks for ventricular arrhythmias and all-cause mortality were evaluated using Cox proportional hazards models. Results Six oxylipins, 17,18-DiHETE (HR = 0.83, 95% CI 0.70 to 0.99 per SD change in oxylipin level), 19,20-DiHDPA (HR = 0.79, 95% CI 0.63 to 0.98), 5,6-DiHETrE (HR = 0.73, 95% CI 0.58 to 0.91), 8,9-DiHETrE (HR = 0.76, 95% CI 0.62 to 0.95), 9,10-DiHOME (HR = 0.81, 95% CI 0.65 to 1.00), and PGF1α (HR = 1.33, 95% CI 1.04 to 1.71) were associated with the risk of appropriate ICD shock after multivariate adjustment for clinical factors. Additionally, 4 oxylipin-to-precursor ratios, 15S-HEPE / FA (20:5-ω3), 17,18-DiHETE / FA (20:5-ω3), 19,20-DiHDPA / FA (20:5-ω3), and 5S-HEPE / FA (20:5-ω3) were positively associated with the risk of all-cause mortality. Conclusion In a prospective cohort of patients with primary prevention ICDs, we identified several novel oxylipin markers that were associated with appropriate shock and mortality using metabolic profiling techniques. These findings may provide new insight into the potential biologic pathways leading to adverse events in this patient population. PMID:27281224

  10. Correlation of Geomagnetic Activity with Implantable Cardioverter Defibrillator Shocks and Antitachycardia Pacing

    PubMed Central

    Ebrille, Elisa; Konecny, Tomas; Konecny, Dana; Spacek, Radim; Jones, Paul; Ambroz, Pavel; DeSimone, Christopher V; Powell, Brian D; Hayes, David L; Friedman, Paul A; Asirvatham, Samuel J

    2016-01-01

    Objective Small-scale observational studies have suggested that geomagnetic activity (GMA) may negatively correlate with the frequency of life-threatening arrhythmias. We investigated a potential relationship between implantable cardioverter defibrillator (ICD) therapies and daily GMA recorded in a large database. Patients and Methods The ALTITUDE database, derived from the Boston Scientific LATITUDE remote monitoring system, was retrospectively analyzed for the frequency of ICD therapies. Daily GMA was expressed as the planetary K-index and the integrated A-index and graded as Levels I – quiet, II – unsettled, III – active, and IV – storm. Results A daily mean of 59,468 ± 11,397 patients were monitored between 2009 and 2012. The distribution of days according to GMA was: Level I 75%, Level II 18%, Level III 5%, Level IV 2%. The daily number of ICD shocks received per 1000 active patients in the database was 1.29 ± 0.47, 1.17 ± 0.46, 1.03 ± 0.37, and 0.94 ± 0.29 on Level I, Level II, Level III, and Level IV days respectively; the daily sum of shocks and antitachycardia pacing (ATP) therapies was 9.29 ± 2.86, 8.46 ± 2.45, 7.92 ± 1.80, and 7.83 ± 2.28 on quiet, unsettled, active and storm days respectively. A statistically significant inverse relationship between GMA and the frequency of ICD therapies was identified, with the most pronounced difference between Level I and Level IV days (p < .001 for shocks, p = .008 for shocks + ATP). Conclusion In a large scale cohort analysis, ICD therapies were delivered less frequently on days of higher GMA, confirming the previous pilot data and suggesting that higher GMA does not pose an increased risk of arrhythmias using ICD therapies as a surrogate marker. Further studies are needed to gain an in-depth understanding of the underlying mechanisms. PMID:25659238

  11. Value of an automatic external defibrillator printout as a diagnostic tool after successful AED use on a child.

    PubMed

    van Sambeeck, S J; van Gent, R; Schroër, C; Halbertsma, F J J

    2013-04-22

    A 6-year-old girl without any medical history experienced a drowning incident for a duration of 2 min, according to witnesses. This was followed by cardiopulmonary resuscitation, during which the automatic external defibrillator (AED) detected a shockable rhythm and subsequently delivered a single electroshock. At the time of admission, her medical history was unclear, and as her chest had been wet, it was not clear if the AED had been capable of correctly analysing the rhythm. The AED printout, however, revealed ventricular fibrillation (VF), which proved to be a primary cardiac cause at the time of the incident. This case report confirms the assumption that the AED can adequately perform rhythm analysis on children and convert VF into sinus rhythm. Moreover, the AED printout can provide information about the rhythm that is necessary for the diagnosis of an underlying cardiac disease.

  12. Outcomes in African-Americans Undergoing Cardioverter Defibrillators Implantation for Primary Prevention of Sudden Cardiac Death: Findings from The Prospective Observational Study of Implantable Cardioverter-Defibrillators (PROSE-ICD)

    PubMed Central

    Zhang, Yiyi; Kennedy, Robert; Blasco-Colmenares, Elena; Butcher, Barbara; Norgard, Sanaz; Eldadah, Zayd; Dickfeld, Timm; Ellenbogen, Kenneth A.; Marine, Joseph E.; Guallar, Eliseo; Tomaselli, Gordon F.; Cheng, Alan

    2014-01-01

    Background Implantable cardioverter defibrillators (ICDs) reduce the risk of death in patients with left ventricular dysfunction. Little is known regarding the benefit of this therapy in African-Americans (AA). Objective To determine the association between African-American race and outcomes in a cohort of primary prevention cardioverter defibrillators (ICD) patients. Methods We conducted a prospective cohort study of patients with systolic heart failure who underwent ICD implantation for primary prevention of sudden cardiac death. The primary endpoint was appropriate ICD shock defined as a shock for rapid ventricular tachyarrhythmias. The secondary endpoint was all-cause mortality. Results There were 1,189 patients (447 AAs and 712 non-AAs) enrolled. Over a median follow-up of 5.1 years, a total of 137 patients experienced an appropriate ICD shock, and 343 died (294 of whom died without receiving an appropriate ICD shock). The multivariate adjusted hazard ratios (95% CI) comparing AAs vs. non-AAs were 1.24 (0.96 to 1.59) for all-cause mortality, 1.33 (1.02, 1.74) for all-cause mortality without receiving appropriate ICD shock, and 0.78 (0.51, 1.19) for appropriate ICD shock. Ejection fraction, diabetes, and hypertension appeared to explain 24.1% (10.1 to 69.5%), 18.7% (5.3 to 58.0%), and 13.6% (3.8 to 53.6%) of the excess risk of mortality in AAs, with a large proportion of the mortality difference remains unexplained. Conclusions In patients with primary prevention ICDs, AAs had an increased risk of dying without receiving an appropriate ICD shock compared to non-AAs. PMID:24793459

  13. Trends and In-Hospital Outcomes Associated With Adoption of the Subcutaneous Implantable Cardioverter Defibrillator in the United States

    PubMed Central

    Friedman, Daniel J.; Parzynski, Craig S.; Varosy, Paul D.; Prutkin, Jordan M.; Patton, Kristen K.; Mithani, Ali; Russo, Andrea M.; Curtis, Jeptha P.; Al-Khatib, Sana M.

    2016-01-01

    IMPORTANCE Trends and in-hospital outcomes associated with early adoption of the subcutaneous implantable cardioverter defibrillator (S-ICD) in the United States have not been described. OBJECTIVES To describe early use of the S-ICD in the United States and to compare in-hospital outcomes among patients undergoing S-ICD vs transvenous (TV)-ICD implantation. DESIGN, SETTING, AND PARTICIPANTS A retrospective analysis of 393 734 ICD implants reported to the National Cardiovascular Data Registry ICD Registry, a nationally representative US ICD registry, between September 28, 2012 (US Food and Drug Administration S-ICD approval date), and March 31, 2015, was conducted. A 1:1:1 propensity-matched analysis of 5760 patients was performed to compare in-hospital outcomes among patients with S-ICD with those of patients with single-chamber (SC)–ICD and dual-chamber (DC)–ICD. MAIN OUTCOMES AND MEASURES Analysis of trends in S-ICD adoption as a function of total ICD implants and comparison of in-hospital outcomes (death, complications, and defibrillation threshold [DFT] testing) among S-ICD and TV-ICD recipients. RESULTS Of the 393 734 ICD implants evaluated during the study period, 3717 were S-ICDs (0.9%). A total of 109 445 (27.8%) of the patients were female; the mean (SD) age was 67.03 (13.10) years. Use of ICDs increased from 0.2%during the fourth quarter of 2012 to 1.9% during the first quarter of 2015. Compared with SC-ICD and DC-ICD recipients, those with S-ICDs were more often younger, female, black, undergoing dialysis, and had experienced prior cardiac arrest. Among 2791 patients with S-ICD who underwent DFT testing, 2588 (92.7%), 2629 (94.2%), 2635 (94.4%), and 2784 (99.7%) were successfully defibrillated (≤65, ≤70, ≤75, and≤80 J, respectively). In the propensity-matched analysis of 5760 patients, in-hospital complication rates associated with S-ICDs (0.9%) were comparable to those of SC-ICDs (0.6%) (P = .27) and DC-ICD rates (1.5%) (P = .11). Mean (SD

  14. Capsule endoscopy in patients with cardiac pacemakers, implantable cardioverter defibrillators, and left heart devices: a review of the current literature.

    PubMed

    Bandorski, Dirk; Keuchel, Martin; Brück, Martin; Hoeltgen, Reinhard; Wieczorek, Marcus; Jakobs, Ralf

    2011-01-01

    Background and Study Aims. Capsule endoscopy is an established tool for investigation of the small intestine. Because of limited clinical experience in patients with cardiac devices, the Food and Drug Administration and the manufacturer recommended not to use capsule endoscopy in these patients. The vast majority of investigations did not reveal any interference between capsule endoscopy and cardiac devices. Methods. Studies investigating interference between CE and cardiac devices were analysed. For the review we considered studies published in English or German and indexed in Medline, as well as highly relevant abstracts. Results. In vitro and in vivo studies mainly revealed no interference between capsule endoscopy and cardiac devices. Technical data of capsule endoscopy (Given Imaging) reveal that interference with cardiac pacemakers and implantable cardioverter defibrillator is impossible. Telemetry can interfere with CE video. Conclusion. The clinical use of capsule endoscopy (Given Imaging) is unproblematic in patients with cardiac pacemakers.

  15. Programmed Ventricular Stimulation to Risk Stratify for Early Cardioverter-Defibrillator Implantation to Prevent Tachyarrhythmias following Acute Myocardial Infarction (PROTECT-ICD): Trial Protocol, Background and Significance.

    PubMed

    Zaman, Sarah; Taylor, Andrew J; Stiles, Martin; Chow, Clara; Kovoor, Pramesh

    2016-11-01

    The 'Programmed Ventricular Stimulation to Risk Stratify for Early Cardioverter-Defibrillator Implantation to Prevent Tachyarrhythmias following Acute Myocardial Infarction' (PROTECT-ICD) trial is an Australian-led multicentre randomised controlled trial targeting prevention of sudden cardiac death in patients who have at least moderately reduced cardiac function following a myocardial infarct (MI). The primary objective of the trial is to assess whether electrophysiological study to guide prophylactic implantation of an implantable cardioverter-defibrillator (ICD) early following MI (first 40 days) will lead to a significant reduction in sudden cardiac death and non-fatal arrhythmia. The secondary objective is to assess the utility of cardiac MRI (CMR) in assessing early myocardial characteristics, and its predictive value for both inducible ventricular tachycardia (VT) at EPS and SCD/ non-fatal arrhythmia at follow-up.

  16. Attrition and Adherence in a Web-Based Distress Management Program for Implantable Cardioverter Defibrillator Patients (WEBCARE): Randomized Controlled Trial

    PubMed Central

    Alings, Marco; van der Voort, Pepijn; Theuns, Dominic; Bouwels, Leon; Herrman, Jean-Paul; Valk, Suzanne

    2014-01-01

    Background WEB-Based Distress Management Program for Implantable CARdioverter defibrillator Patients (WEBCARE) is a Web-based randomized controlled trial, designed to improve psychological well-being in patients with an implantable cardioverter defibrillator (ICD). As in other Web-based trials, we encountered problems with attrition and adherence. Objective In the current study, we focus on the patient characteristics, reasons, and motivation of (1) completers, (2) those who quit the intervention, and (3) those who quit the intervention and the study in the treatment arm of WEBCARE. Methods Consecutive first-time ICD patients from six Dutch referral hospitals were approached for participation. After signing consent and filling in baseline measures, patients were randomized to either the WEBCARE group or the Usual Care group. Results The treatment arm of WEBCARE contained 146 patients. Of these 146, 34 (23.3%) completed the treatment, 88 (60.3%) dropped out of treatment but completed follow-up, and 24 (16.4%) dropped out of treatment and study. Results show no systematic differences in baseline demographic, clinical, or psychological characteristics between groups. A gradual increase in dropout was observed with 83.5% (122/146) completing the first lesson, while only 23.3% (34/146) eventually completed the whole treatment. Reasons most often given by patients for dropout were technical problems with the computer, time constraints, feeling fine, and not needing additional support. Conclusions Current findings underline the importance of focusing on adherence and dropout, as this remains a significant problem in behavioral Web-based trials. Examining possibilities to address barriers indicated by patients might enhance treatment engagement and improve patient outcomes. Trial Registration Clinicaltrials.gov: NCT00895700; http://www.clinicaltrials.gov/ct2/show/NCT00895700 (Archived by WebCite at http://www.webcitation.org/6NCop6Htz). PMID:24583632

  17. Survival Benefit of Implantable Cardioverter-Defibrillators in Left Ventricular Assist Device-Supported Heart Failure Patients

    PubMed Central

    Refaat, Marwan M.; Tanaka, Toshikazu; Kormos, Robert L; McNamara, Dennis; Teuteberg, Jeffrey; Winowich, Steve; London, Barry; Simon, Marc A

    2012-01-01

    Background Implantable Cardioverter-Defibrillators (ICDs) reduce mortality in heart failure (HF). In patients requiring ventricular assist device (VAD), the benefit from ICD therapy is not well established. The aim of the study is to define the impact of ICD on outcomes in VAD - supported patients. Methods and Results We reviewed data for consecutive adult HF patients receiving VAD as bridge-to-transplantation from 1996 to 2003. Primary outcome was survival to transplantation. A total of 144 VADs were implanted [85 left ventricular (LVAD), 59 biventricular (BIVAD), age 50±12 years, 77% male, LVEF 18±9%, 54% ischemic]. Mean length of support was 119 days (range 1–670); 103 (72%) patients survived to transplantation. Forty-five patients had an ICD (33 LVAD, 12 BIVAD). More LVAD patients had an appropriate ICD shock before implantation than afterwards (16 vs. 7, p=0.02). There was a trend towards higher shock frequency before LVAD implant than after (3.3±5.2 vs 1.1±3.8 shocks/year, p=0.06). Mean time to first shock after VAD implant was 129±109 days. LVAD-supported patients with an ICD were significantly more likely to survive to transplantation (LVAD: 1-year actuarial survival to transplantation 91% with ICD vs. 57% without ICD, log-rank p=0.01; BIVAD: 54% vs. 47%, log-rank p=NS). An ICD was associated with significantly increased survival in a multivariate model controlling for confounding variables (OR 2.54, 95% CI 1.04-6.21, p=0.04). Conclusions Shock frequency decreases after VAD implantation, likely due to ventricular unloading, but appropriate ICD shocks still occur in 21% of patients. An ICD is associated with improved survival in LVAD-supported HF patients. PMID:22300782

  18. Neutrophil to lymphocyte ratio predicts appropriate therapy in idiopathic dilated cardiomyopathy patients with primary prevention implantable cardioverter defibrillator

    PubMed Central

    Uçar, Fatih M.; Açar, Burak

    2017-01-01

    Objectives: To investigate whether an inflammatory marker of neutrophil to lymphocyte ratio (NLR) predicts appropriate implantable cardioverter defibrillator (ICD) therapy (shock or anti tachycardia pacing) in idiopathic dilated cardiomyopathy (IDC) patients. Methods: We retrospectively examined IDC patients (mean age: 58.3 ± 11.8 years, 81.5% male) with ICD who admitted to outpatient clinic for pacemaker control at 2 tertiary care hospitals in Ankara and Edirne, Turkey from January 2013-2015. All ICDs were implanted for primary prevention. Hematological and biochemical parameters were measured prior procedure. Results: Over a median follow-up period of 43 months (Range 7-125), 68 (33.1%) patients experienced appropriate ICD therapy. The NLR was increased in patients that received appropriate therapy (4.39 ± 2.94 versus 2.96 ± 1.97, p<0.001). To identify independent risk factors for appropriate therapy, a multivariate linear regression model was conducted and age (β=0.163, p=0.013), fasting glucose (β=0.158, p=0.017), C-reactive protein (CRP) (β=0.289, p<0.001) and NLR (β=0.212, p<0.008) were found to be independent risk factors for appropriate ICD therapy. Conclusions: Before ICD implantation by using NLR and CRP, arrhythmic episodes may be predictable and better antiarrhythmic medical therapy optimization may protect these IDC patients from unwanted events. PMID:28133686

  19. Failure of a novel silicone–polyurethane copolymer (Optim™) to prevent implantable cardioverter-defibrillator lead insulation abrasions

    PubMed Central

    Hauser, Robert G.; Abdelhadi, Raed H.; McGriff, Deepa M.; Kallinen Retel, Linda

    2013-01-01

    Aim The purpose of this study was to determine if Optim™, a unique copolymer of silicone and polyurethane, protects Riata ST Optim and Durata implantable cardioverter-defibrillator (ICD) leads (SJM, St Jude Medical Inc., Sylmar, CA, USA) from abrasions that cause lead failure. Methods and results We searched the US Food and Drug Administration's (FDA's) Manufacturers and User Device Experience (MAUDE) database on 13 April 2012 using the simple search terms ‘Riata ST Optim™ abrasion analysis’ and ‘Durata abrasion analysis’. Lead implant time was estimated by subtracting 3 months from the reported lead age. The MAUDE search returned 15 reports for Riata ST Optim™ and 37 reports for Durata leads, which were submitted by SJM based on its analyses of returned leads for clinical events that occurred between December 2007 and January 2012. Riata ST Optim™ leads had been implanted 29.1 ± 11.7 months. Eight of 15 leads had can abrasions and three abrasions were caused by friction with another device, most likely another lead. Four of these abrasions resulted in high-voltage failures and one death. One failure was caused by an internal insulation defect. Durata leads had been implanted 22.2 ± 10.6 months. Twelve Durata leads had can abrasions, and six leads had abrasions caused by friction with another device. Of these 18 can and other device abrasions, 13 (72%) had electrical abnormalities. Low impedances identified three internal insulation abrasions. Conclusions Riata ST Optim™ and Durata ICD leads have failed due to insulation abrasions. Optim™ did not prevent these abrasions, which developed ≤4 years after implant. Studies are needed to determine the incidence of these failures and their clinical implications. PMID:22915789

  20. High Dose Radiotherapy to Automated Implantable Cardioverter-Defibrillator: A Case Report and Review of the Literature

    PubMed Central

    Jabbour, Salma K.

    2014-01-01

    We report a case of successful full-dose chemoradiotherapy to stage IIIB nonsmall cell lung cancer (NSCLC) in a 59-year-old man with extensive cardiac history and an automated implantable cardioverter-defibrillator (AICD) located within the radiotherapeutic field. In this case, the AICD was a St. Jude Medical Fortify Assura VR 1257-40Q ICD, and it was implanted prophylactically during bypass grafting. Although we do not recommend routine radiotherapy dose to exceed recommended current guidelines due to the potential risks to the patient, this is a situation where relocation of the device was not possible. Fortunately, our patient was not AICD-dependent; so following much discussion and deliberation, the decision was made to treat the patient with AICD in place. The patient completed definitive chemoradiotherapy with concurrent cisplatin and etoposide and thoracic irradiation to 69.6 Gy. The minimum, maximum, and mean doses to the AICD directly were 13.5 Gy, 52.4 Gy, and 29.3 Gy, respectively. The device withstood full thoracic radiation dose, and the patient denied cardiac symptoms during the time before, during, and after completion of therapy. We sought to offer this case for both teaching and guidance in practice and to contribute to the published literature currently available in this area. PMID:25276450

  1. High-intensity cardiac rehabilitation training of a firefighter after placement of an implantable cardioverter-defibrillator

    PubMed Central

    DeJong, Sandra; Arnett, Justin K.; Kennedy, Kathleen; Franklin, Jay O.; Berbarie, Rafic F.

    2014-01-01

    Firefighters who have received an implantable cardioverter-defibrillator (ICD) are asked to retire or are permanently placed on restricted duty because of concerns about their being incapacitated by an ICD shock during a fire emergency. We present the case of a 40-year-old firefighter who, after surviving sudden cardiac arrest and undergoing ICD implantation, sought to demonstrate his fitness for active duty by completing a high-intensity, occupation-specific cardiac rehabilitation training program. The report details the exercise training, ICD monitoring, and stress testing that he underwent. During the post-training treadmill stress test in firefighter turnout gear, the patient reached a functional capacity of 17 metabolic equivalents (METs), exceeding the 12-MET level required for his occupation. He had no ICD shock therapy or recurrent sustained arrhythmias during stress testing or at any time during his cardiac rehabilitation stay. By presenting this case, we hope to stimulate further discussion about firefighters who have an ICD, can meet the functional capacity requirements of their occupation, and want to return to work. PMID:24982569

  2. Safety Profile of Liver FibroScan in Patients with Cardiac Pacemakers or Implantable Cardioverter-Defibrillators

    PubMed Central

    Pranke, Stephanie; Rashidi, Farid; Nosib, Shravan; Worobetz, Lawrence

    2017-01-01

    Background. Emerging evidence suggests that nonalcoholic fatty liver disease (NAFLD) is associated with coronary artery diseases and arrhythmias. The FibroScan (Echosens, France), a widely available, noninvasive device, is able to detect liver fibrosis and steatosis within this patient population. However, the FibroScan is currently contraindicated in patients with cardiac pacemakers (PM) or implantable cardioverter-defibrillators (ICD). Objective. To determine the safety profile of FibroScan testing in patients with PM or ICD. Methods. Consecutive outpatients undergoing routine device interrogations at a tertiary level teaching hospital underwent simultaneous liver stiffness measurements. PM or ICD performance data, device types, patient demographics, medical history, and previous laboratory and conventional liver imaging results were collected. Results. Analysis of 107 subjects with 33 different types of implanted cardiac devices, from 5 different companies (Medtronic, Sorin, ELA Medical, Boston Scientific, and St. Jude), did not demonstrate any adverse events as defined by abnormal device sensing/pacing or ICD firing. This population included high risk subjects undergoing active pacing (n = 53) and with right pectoral PM placement (n = 1). None of the subjects had any clinical signs of decompensated congestive heart failure or cirrhosis during the exam. Conclusion. TE with FibroScan can be safely performed in patients with PM or ICD. PMID:28349045

  3. Behavioral interventions in patients with an implantable cardioverter defibrillator: Lessons learned and where to go from here?

    PubMed Central

    Habibović, Mirela; Burg, Matthew M.; Pedersen, Susanne S.

    2013-01-01

    Background The implantable cardioverter defibrillator (ICD) is the first line treatment for primary and secondary prevention of sudden cardiac death. A subgroup of patients experiences psychological distress post implant, and no clear evidence base exists regarding how best to address patients’ needs. The aim of this critical review is to provide an overview of behavioral interventions in ICD patients to date, and to delineate directions for future research using lessons learned from the ongoing RISTA and WEBCARE trials. Methods We searched the PubMed and PsycInfo databases to identify reports of behavioral trials targeting distress and related factors in ICD patients published between 1980 and April 2012. Results We identified 17 trials for the review. Generally, compared to usual care, behavioral interventions were associated with reduced anxiety and depression, and improved physical functioning, with effect sizes ranging from small to moderate-large (0.10 – 1.79 for anxiety; 0.23 – 1.20 for depression). Important limitations were small sample sizes and potential selection bias, hampering generalizability of the results. In addition to a need for larger trials, experiences from the RISTA and WEBCARE trials suggest that intervention trials tailored to the individual patient may be the way forward.. Conclusions Behavioral interventions show promise with respect to reducing distress in ICD patients. Large-scale intervention trials targeted to the individual needs and preferences of patients are warranted, as a ‘one size fits all’ approach is unlikely to work for all ICD patients. PMID:23438053

  4. Clinical course of arrhythmogenic right ventricular cardiomyopathy in the era of implantable cardioverter-defibrillators and radiofrequency catheter ablation.

    PubMed

    Komura, Masatoshi; Suzuki, Jun-Ichi; Adachi, Susumu; Takahashi, Atsushi; Otomo, Kenichiro; Nitta, Junichi; Nishizaki, Mitsuhiro; Obayashi, Tohru; Nogami, Akihiko; Satoh, Yasuhiro; Okishige, Kaoru; Hachiya, Hitoshi; Hirao, Kenzo; Isobe, Mitsuaki

    2010-01-01

    This study investigated the clinical course of arrhythmogenic right ventricular cardiomyopathy (ARVC) patients and in particular evaluated the contribution of radiofrequency catheter ablation (RFCA) and an implantable cardioverter-defibrillator (ICD) to the treatment of ARVC. ARVC is a myocardial disorder and a cause of sudden cardiac death due to ventricular tachycardia (VT). Little is known about its prognosis in Japanese ARVC patients. Thirty-five ARVC patients were studied. Mean age of patients whose onset of ARVC was congestive heart failure (CHF) (66.0 +/- 4.0 years) was significantly higher than those whose onset was VT (44.5 +/- 14.8 years, P < 0.05). ARVC patients with CHF onset showed significantly higher death rates compared to those with VT onset. ICD treatment significantly reduced episodes of hospitalization due to VT (0.1 +/- 0.4 episodes) in comparison to treatment by RFCA (1.7 +/- 2.2 episodes, P < 0.03). RFCA treatment did not reduce recurrence of VT in the follow-up period. ICD therapy showed comparable mortality to RFCA treatment. The prognosis of ARVC with CHF onset is poor. ICD therapy significantly reduced hospitalization due to VT compared with RFCA treatment. ICD implantation in combination with medication may be a better treatment for ARVC.

  5. Successful Delivery by a Cesarean Section in a Parturient with Severe Dilated Cardiomyopathy, an Implantable Cardioverter Defibrillator, and a Repaired Tetralogy of Fallot

    PubMed Central

    Al-Aqeedi, Rafid Fayadh; Alnabti, Abdulrahman; Al-Ani, Fuad; Dabdoob, Wafer; Abdullatef, Waleed Khalid

    2011-01-01

    Repaired congenital heart disease has become more prevalent in women of childbearing age. We report an unusual case of a 24-year-old multigravida with a repaired tetralogy of Fallot, severe dilated cardiomyopathy, and implantable cardioverter defibrillator placement who was managed successfully by a cesarean section three times. This case underscores the impact of such events on maternal and fetal safety and the importance of a multidisciplinary approach in the management of pregnant patients with complex congenital and medical problems. PMID:21731806

  6. [Positive microvolt T-wave alternans as a marker of ventricular arrhythmia trigering during cardioverter-defibrillator implantation].

    PubMed

    Wierzbowski, Robert; Michałkiewicz, Dariusz; Cholewa, Marian; Jacewicz, Katarzyna; Gniłka, Anna; Adamus, Jerzy

    2006-10-01

    Microvolt T-wave alternans (MTWA) is promising method for noninvasive assessment of arrhythmic risk, but its role hasn't established yet. The aim of this study was to establish the MTWA potency to predict the ventricular arrhythmia triggering during implantable cordioverter-defibrillator (ICD) implantation. Material and metods. The study group consisted of 21 patients, aged 63.0+/-8.0 years; EF was 38.0+/-12.8%. Seventeen of them had a history of myocardial infarction and 4 had non-ischemic cardiomyopathy. The reason for ICD implantation were secondary prevention due to nonfatal cardiac arrest caused by VF/VT in nineteen patients and in two patients ICD was implanted because of unexplained syncope and low EF (< or =35%). All patients underwent VT/VF triggering during device implantation caused by electrophysiological study (EPS). If this proved ineffective aggressive protocol of 50 Hz BURST and T SHOCK was applied. After ICD implantation the following tests were performed: ECG with HR, QRS and QTc evaluation, 24-hour ECG Holter monitoring with HRV assessment and MTWA evaluation during treadmill exercise test. Results. In the group with VT/VF induced by less aggressive protocol (EPS), group I (n = 10) MTWA was present in nine patients, in one the result of MTWA was indeterminate. In the group with VT/VF induced by more aggressive protocol, group II (n = 11) MTWA was present in four patients, indeterminate in four and absent in three. There was a significant (p = 0.017) difference between group I and II in the frequency of positive result of MTWA. There were no differences between the two groups according to time domain parameters of HRV such as SDNN, RMSSD and PNN50 and QTc. There was a significant difference between the two groups in time duration of QRS complexes, 118.9+/-14.7 vs. 105.6+/-11.5 accordingly (p < 0.04). Conclusions. MTWA may help identify patients in whom VTNVF is more easily inducible by electrophysiologic study during ICD implantation. It is easier

  7. Public Claims about Automatic External Defibrillators: An Online Consumer Opinions Study

    PubMed Central

    2011-01-01

    Background Patients are no longer passive recipients of health care, and increasingly engage in health communications outside of the traditional patient and health care professional relationship. As a result, patient opinions and health related judgements are now being informed by a wide range of social, media, and online information sources. Government initiatives recognise self-delivery of health care as a valuable means of responding to the anticipated increased global demand for health resources. Automated External Defibrillators (AEDs), designed for the treatment of Sudden Cardiac Arrest (SCA), have recently become available for 'over the counter' purchase with no need for a prescription. This paper explores the claims and argumentation of lay persons and health care practitioners and professionals relating to these, and how these may impact on the acceptance, adoption and use of these devices within the home context. Methods We carry out a thematic content analysis of a novel form of Internet-based data: online consumer opinions of AED devices posted on Amazon.com, the world's largest online retailer. A total of #83 online consumer reviews of home AEDs are analysed. The analysis is both inductive, identifying themes that emerged from the data, exploring the parameters of public debate relating to these devices, and also driven by theory, centring around the parameters that may impact upon the acceptance, adoption and use of these devices within the home as indicated by the Technology Acceptance Model (TAM). Results Five high-level themes around which arguments for and against the adoption of home AEDs are identified and considered in the context of TAM. These include opinions relating to device usability, usefulness, cost, emotional implications of device ownership, and individual patient risk status. Emotional implications associated with AED acceptance, adoption and use emerged as a notable factor that is not currently reflected within the existing TAM

  8. Wrong detection of ventricular fibrillation in an implantable cardioverter defibrillator caused by the movement near the MRI scanner bore.

    PubMed

    Mattei, Eugenio; Censi, Federica; Triventi, Michele; Mancini, Matteo; Napolitano, Antonio; Genovese, Elisabetta; Cannata, Vittorio; Falsaperla, Rosaria; Calcagnini, Giovanni

    2015-01-01

    The static magnetic field generated by MRI systems is highly non-homogenous and rapidly decreases when moving away from the bore of the scanner. Consequently, the movement around the MRI scanner is equivalent to an exposure to a time-varying magnetic field at very low frequency (few Hz). For patients with an implanted cardiac stimulators, such as an implantable cardioverter/defibrillator (ICD), the movements inside the MRI environment may thus induce voltages on the loop formed by the leads of the device, with the potential to affect the behavior of the stimulator. In particular, the ICD's detection algorithms may be affected by the induced voltage and may cause inappropriate sensing, arrhythmia detections, and eventually inappropriate ICD therapy.We performed in-vitro measurements on a saline-filled humanshaped phantom (male, 170 cm height), equipped with an MRconditional ICD able to transmit in real-time the detected cardiac activity (electrograms). A biventricular implant was reproduced and the ICD was programmed in standard operating conditions, but with the shock delivery disabled. The electrograms recorded in the atrial, left and right ventricle channels were monitored during rotational movements along the vertical axis, in close proximity of the bore. The phantom was also equipped with an accelerometer and a magnetic field probe to measure the angular velocity and the magnetic field variation during the experiment. Pacing inhibition, inappropriate detection of tachyarrhythmias and of ventricular fibrillation were observed. Pacing inhibition began at an angular velocity of about 7 rad/s, (dB/dt of about 2 T/s). Inappropriate detection of ventricular fibrillation occurred at about 8 rad/s (dB/dt of about 3 T/s). These findings highlight the need for a specific risk assessment of workers with MR-conditional ICDs, which takes into account also effects that are generally not considered relevant for patients, such as the movement around the scanner bore.

  9. "Two for the Price of One": A Single-Lead Implantable Cardioverter-Defibrillator System with a Floating Atrial Dipole.

    PubMed

    E Worden Md, Nicole; Alqasrawi Md, Musab; M Krothapalli Md, Siva; Mazur Md, Alexander

    2016-01-01

    In patients known to be a high risk for sudden cardiac arrest, implantable cardioverter defibrillators (ICD) are a proven therapy to reduce risk of death. However, in patients without conventional indications for pacing, the optimal strategy for type of device, dual- versus single-chamber, remains debatable. The benefit of prophylactic pacing in this category of patients has never been documented. Although available atrial electrograms in a dual chamber system improve interpretation of stored arrhythmia events, allow monitoring of atrial fibrillation and may potentially reduce the risk of inappropriate shocks by enhancing automated arrhythmia discrimination, the use of dual-chamber ICDs has a number of disadvantages. The addition of an atrial lead adds complexity to implantation and extraction procedures, increases procedural cost and is associated with a higher risk of periprocedural complications. The single lead pacing system with ability to sense atrial signals via floating atrial electrodes (VDD) clinically became available in early 1980's but did not gain much popularity due to inconsistent atrial sensing and concerns about the potential need for an atrial lead if sinus node fails. Most ICD patients do not have indications for pacing at implantation and subsequent risk of symptomatic bradycardia seems to be low. The concept of atrial sensing via floating electrodes has recently been revitalized in the Biotronik DX ICD system (Biotronik, SE & Co., Berlin, Germany) aiming to provide all of the potential advantages of available atrial electrograms without the risks and incremental cost of an additional atrial lead. Compared to a traditional VDD pacing system, the DX ICD system uses an optimized (15 mm) atrial dipole spacing and improved atrial signal processing to offer more reliable atrial sensing. The initial experience with the DX system indicates that the clinically useful atrial signal amplitude in sinus rhythm remains stable over time. Future studies are

  10. Canadian Cardiovascular Society/Canadian Anesthesiologists' Society/Canadian Heart Rhythm Society joint position statement on the perioperative management of patients with implanted pacemakers, defibrillators, and neurostimulating devices.

    PubMed

    Healey, Jeff S; Merchant, Richard; Simpson, Chris; Tang, Timothy; Beardsall, Marianne; Tung, Stanley; Fraser, Jennifer A; Long, Laurene; van Vlymen, Janet M; Manninen, Pirjo; Ralley, Fiona; Venkatraghavan, Lashmi; Yee, Raymond; Prasloski, Bruce; Sanatani, Shubhayan; Philippon, François

    2012-01-01

    There are more than 200,000 Canadians living with permanent pacemakers or implantable defibrillators, many of whom will require surgery or invasive procedures each year. They face potential hazards when undergoing surgery; however, with appropriate planning and education of operating room personnel, adverse device-related outcomes should be rare. This joint position statement from the Canadian Cardiovascular Society (CCS) and the Canadian Anesthesiologists' Society (CAS) has been developed as an accessible reference for physicians and surgeons, providing an overview of the key issues for the preoperative, intraoperative, and postoperative care of these patients. The document summarizes the limited published literature in this field, but for most issues, relies heavily on the experience of the cardiologists and anesthesiologists who contributed to this work. This position statement outlines how to obtain information about an individual's type of pacemaker or implantable defibrillator and its programming. It also stresses the importance of determining if a patient is highly pacemaker-dependent and proposes a simple approach for nonelective evaluation of dependency. Although the document provides a comprehensive list of the intraoperative issues facing these patients, there is a focus on electromagnetic interference resulting from electrocautery and practical guidance is given regarding the characteristics of surgery, electrocautery, pacemakers, and defibrillators which are most likely to lead to interference. The document stresses the importance of preoperative consultation and planning to minimize complications. It reviews the relative merits of intraoperative magnet use vs reprogramming of devices and gives examples of situations where one or the other approach is preferable.

  11. Training lay persons to use automatic external defibrillators: success of initial training and one-year retention of skills.

    PubMed

    Cummins, R O; Schubach, J A; Litwin, P E; Hearne, T R

    1989-03-01

    This study was conducted to determine the feasibility of recruitment of lay persons to use automatic external defibrillators (AEDs), the effectiveness of their initial training, and the need for and frequency of retraining over time. Volunteers (n = 146), recruited from a variety of settings, included security personnel and administrative staff from large corporate centers, supervisors from senior care and exercise facilities, and employees in high-rise office buildings. Seven sites for 14 AEDs were recruited. In a single, two-hour class, participants learned to identify and respond to cardiac arrest, to notify emergency personnel, to retrieve and attach the semiautomatic (shock advisory) AED, and to respond to instructions presented on the display screen of the device. A skills check list was used to grade each student on performance of cardiopulmonary resuscitation, operation of the device, and time required to deliver an electric countershock. Retesting was performed one or more times after initial training to assess skill retention. The study lasted 1 year. All age groups, both sexes, and each responder type easily learned to operate the AED, with a trend for lower performance scores in people aged greater than 60 years. Performance time and skills declined significantly after initial training, but returned to satisfactory levels after one retraining session and were even higher after two retraining sessions. With retesting, errors that would have prevented delivery of countershocks to patients in ventricular fibrillation were rare (six of 146 tests, 4%). During the year of this study only three cardiac arrests occurred in the study sites.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Ventricular arrhythmias and changes in heart rate preceding ventricular tachycardia in patients with an implantable cardioverter defibrillator.

    PubMed

    Lerma, Claudia; Wessel, Niels; Schirdewan, Alexander; Kurths, Jürgen; Glass, Leon

    2008-07-01

    The objective was to determine the characteristics of heart rate variability and ventricular arrhythmias prior to the onset of ventricular tachycardia (VT) in patients with an implantable cardioverter defibrillator (ICD). Sixty-eight beat-to-beat time series from 13 patients with an ICD were analyzed to quantify heart rate variability and ventricular arrhythmias. The episodes of VT were classified in one of two groups depending on whether the sinus rate in the 1 min preceding the VT was greater or less than 90 beats per minute. In a subset of patients, increased heart rate and reduced heart rate variability was often observed up to 20 min prior to the VT. There was a non-significant trend to higher incidence of premature ventricular complexes (PVCs) before VT compared to control recordings. The patterns of the ventricular arrhythmias were highly heterogeneous among different patients and even within the same patient. Analysis of the changes of heart rate and heart rate variability may have predictive value about the onset of VT in selected patients. The patterns of ventricular arrhythmia could not be used to predict onset of VT in this group of patients.

  13. The power of exercise-induced T-wave alternans to predict ventricular arrhythmias in patients with implanted cardiac defibrillator.

    PubMed

    Burattini, Laura; Man, Sumche; Sweene, Cees A

    2013-01-01

    The power of exercise-induced T-wave alternans (TWA) to predict the occurrence of ventricular arrhythmias was evaluated in 67 patients with an implanted cardiac defibrillator (ICD). During the 4-year follow-up, electrocardiographic (ECG) tracings were recorded in a bicycle ergometer test with increasing workload ranging from zero (NoWL) to the patient's maximal capacity (MaxWL). After the follow-up, patients were classified as either ICD_Cases (n = 29), if developed ventricular tachycardia/fibrillation, or ICD_Controls (n = 38). TWA was quantified using our heart-rate adaptive match filter. Compared to NoWL, MaxWL was characterized by faster heart rates and higher TWA in both ICD_Cases (12-18 μ V vs. 20-39 μ V; P < 0.05) and ICD_Controls (9-15 μ V vs. 20-32 μ V; P < 0.05). Still, TWA was able to discriminate the two ICD groups during NoWL (sensitivity = 59-83%, specificity = 53-84%) but not MaxWL (sensitivity = 55-69%, specificity = 39-74%). Thus, this retrospective observational case-control study suggests that TWA's predictive power for the occurrence of ventricular arrhythmias could increase at low heart rates.

  14. A Pregnancy with Severe Hypertrophic Obstructive Cardiomyopathy after Surgery for an Implantable Cardioverter Defibrillator: A Case Report and Literature Review

    PubMed Central

    Mitsui, Takashi; Ejiri, Kentaro; Hayata, Kei; Ito, Hiroshi; Hiramatsu, Yuji

    2016-01-01

    Hypertrophic obstructive cardiomyopathy (HOCM) is cardiac hypertrophy of ventricular myocardium with left ventricular outflow tract obstruction. We report a pregnancy with HOCM after defibrillator implantation surgery. The patient was a 33-year-old nulligravida and was categorized as New York Heart Association class II. Her brain natriuretic peptide (BNP) level was 724.6 pg/dL at preconception. She received careful pregnancy management. However, because frequent uterine contractions were observed at 25 weeks and 6 days of pregnancy, she was hospitalized, and magnesium sulfate was started as a tocolytic agent. At 27 weeks and 5 days of pregnancy, she had respiratory discomfort and orthopnea with a sudden decrease in peripheral oxygen saturation. Cardiac ultrasonography showed a worsened condition of HOCM and her BNP level was 1418.0 pg/mL. We performed an emergent cesarean section and she delivered a boy weighing 999 g. The Apgar score was 8 and 9 points at 1 and 5 minutes, respectively. The mother's heart failure quickly improved after birth and she was discharged at 10 days postoperatively. Fluctuations in circulatory dynamics during pregnancy may sometimes exacerbate heart disease. Therefore, the risks should be fully explained and careful assessment of cardiac function should be performed during pregnancy in patients with severe HOCM. PMID:27830098

  15. Symbolic Dynamics Analysis of Short Data Sets: an Application to Heart Rate Variability from Implantable Defibrillator Devices

    NASA Astrophysics Data System (ADS)

    Zebrowski, Jan J.; Baranowski, Rafal; Przybylski, Andrzej

    2003-07-01

    A method is described for the assessment of the complexity of short data sets by nonlinear dynamics. The method was devised for and tested on human heart rate recordings approximately 2000 to 9000 RR intervals long which were extracted from the memory of implantable defibrillator devices (ICD). It is, however, applicable in a more general context. The ICDs are meant to control life-threatening episodes of ventricular tachycardia and/or ventricular fibrillation by applying a electric shock to the heart through intracardiac electrodes. It is well known that conventional ICD algorithms yield approximately 20--30 % of spurious interventions. The main aim of this work is to look for nonlinear dynamics methods to enhance the appropriateness of the ICD intervention. We first showed that nonlinear dynamics methods first applied to 24-hour heart rate variability analysis were able to detect the need for the ICD intervention. To be applicable to future ICD use, the methods must also be low in computational requirements. Methods to analyse the complexity of the short and non-stationary sets were devised. We calculated the Shannon entropy of symbolic words obtained in a sliding 50 beat window and analysed the dependence of this complexity measure on the time. Precursors were found extending much earlier time than the time the standard ICD algorithms span.

  16. Efficacy of cognitive behavioral therapy in reducing psychiatric symptoms in patients with implantable cardioverter defibrillator: an integrative review.

    PubMed

    Maia, A C C O; Braga, A A; Soares-Filho, G; Pereira, V; Nardi, A E; Silva, A C

    2014-04-01

    This article is a systematic review of the available literature on the benefits that cognitive behavioral therapy (CBT) offers patients with implanted cardioverter defibrillators (ICDs) and confirms its effectiveness. After receiving the device, some patients fear that it will malfunction, or they remain in a constant state of tension due to sudden electrical discharges and develop symptoms of anxiety and depression. A search with the key words "anxiety", "depression", "implantable cardioverter", "cognitive behavioral therapy" and "psychotherapy" was carried out. The search was conducted in early January 2013. Sources for the search were ISI Web of Knowledge, PubMed, and PsycINFO. A total of 224 articles were retrieved: 155 from PubMed, 69 from ISI Web of Knowledge. Of these, 16 were written in a foreign language and 47 were duplicates, leaving 161 references for analysis of the abstracts. A total of 19 articles were eliminated after analysis of the abstracts, 13 were eliminated after full-text reading, and 11 articles were selected for the review. The collection of articles for literature review covered studies conducted over a period of 13 years (1998-2011), and, according to methodological design, there were 1 cross-sectional study, 1 prospective observational study, 2 clinical trials, 4 case-control studies, and 3 case studies. The criterion used for selection of the 11 articles was the effectiveness of the intervention of CBT to decrease anxiety and depression in patients with ICD, expressed as a ratio. The research indicated that CBT has been effective in the treatment of ICD patients with depressive and anxiety symptoms. Research also showed that young women represented a risk group, for which further study is needed. Because the number of references on this theme was small, further studies should be carried out.

  17. Implantable cardioverter defibrillator lead-related methicillin resistant Staphylococcus aureus endocarditis: Importance of heightened awareness

    PubMed Central

    Anusionwu, Obiora F; Smith, Cheri; Cheng, Alan

    2012-01-01

    Methicillin resistant Staphylococcus aureus (MRSA) septicemia is associated with high morbidity and mortality especially in patients with immunosuppression, diabetes, renal disease and endocarditis. There has been an increase in implantation of cardiac implantable electronic devices (CIED) with more cases of device-lead associated endocarditis been seen. A high index of suspicion is required to ensure patient outcomes are optimized. The excimer laser has been very efficient in helping to ensure successful lead extractions in patients with CIED infections. We present an unusual case report and literature review of MRSA septicemia from device-lead endocarditis and the importance of early recognition and prompt treatment. PMID:22905295

  18. Defibrillator analyzers.

    PubMed

    1999-12-01

    Defibrillator analyzers automate the inspection and preventive maintenance (IPM) testing of defibrillators. They need to be able to test at least four basic defibrillator performance characteristics: discharge energy, synchronized-mode operation, automated external defibrillation, and ECG monitoring. We prefer that they also be able to test a defibrillator's external noninvasive pacing function--but this is not essential if a facility already has a pacemaker analyzer that can perform this testing. In this Evaluation, we tested seven defibrillator analyzers from six suppliers. All seven units accurately measure the energies of a variety of discharge wave-forms over a wide range of energy levels--from 1 J for use in a neonatal intensive care unit to 360 J for use on adult patients requiring maximum discharge energy. Most of the analyzers are easy to use. However, only three of the evaluated units could perform the full range of defibrillator tests that we prefer. We rated these units Acceptable--Preferred. Three more units could perform four of the five tests, they could not test the pacing feature of a defibrillator. These units were rated Acceptable. The seventh unit could perform only discharge energy testing and synchronized-mode testing and was difficult to use. We rate that unit Acceptable--Not Recommended.

  19. Differences Between Access to Follow-Up Care and Inappropriate Shocks Based on Insurance Status of Implantable Cardioverter Defibrillator Recipients.

    PubMed

    Sager, Solomon J; Healy, Chris; Ramireddy, Archana; Rivner, Harold; Viles Gonzalez, Juan F; Coffey, James O; Rossin, Natalia; Lo, Ka M; Goldberger, Jeffrey J; Myerburg, Robert J; Mitrani, Raul D

    2017-02-15

    Differences in implantable cardioverter defibrillator (ICD) utilization based on insurance status have been described, but little is known about postimplant follow-up patterns associated with insurance status and outcomes. We collected demographic, clinical, and device data from 119 consecutive patients presenting with ICD shocks. Insurance status was classified as uninsured/Medicaid (uninsured) or private/Health Maintenance Organization /Medicare (insured). Shock frequencies were analyzed before and after a uniform follow-up pattern was implemented regardless of insurance profile. Uninsured patients were more likely to present with an inappropriate shock (63% vs 40%, p = 0.01), and they were more likely to present with atrial fibrillation (AF) as the shock trigger (37% vs 19%, p = 0.04). Uninsured patients had a longer interval between previous physician contact and index ICD shock (147 ± 167 vs 83 ± 124 days, p = 0.04). Patients were followed for a mean of 521 ± 458 days after being enrolled in a uniform follow-up protocol, and there were no differences in the rate of recurrent shocks based on insurance status. In conclusion, among patients presenting with an ICD shock, underinsured/uninsured patients had significantly longer intervals since previous physician contact and were more likely to present with inappropriate shocks and AF, compared to those with private/Medicare coverage. After the index shock, both groups were followed uniformly, and the differences in rates of inappropriate shocks were mitigated. This observation confirms the importance of regular postimplant follow-up as part of the overall ICD management standard.

  20. Statins reduce appropriate implantable cardioverter-defibrillator shocks in ischemic cardiomyopathy with no benefit in nonischemic cardiomyopathy.

    PubMed

    Contractor, Tahmeed; Beri, Abhimanyu; Gardiner, Joseph; Ardhanari, Sivakumar; Thakur, Ranjan

    2012-11-01

    Statins have been hypothesized to decrease ventricular arrhythmias through a direct antiarrhythmic effect. Clinical studies have demonstrated a clear reduction only in populations with underlying ischemic heart disease. This study was designed to compare the effect of statins on appropriate shocks between ischemic and nonischemic cardiomyopathy. Patients with an ejection fraction 35% or less who received an implantable cardioverter-defibrillator and had follow-up for at least 1 month were included. The ischemic and nonischemic groups were divided into statin treatment and control subgroups and the occurrence of appropriate shocks was compared. The frequency of shocks was analyzed using negative binomial models to account for overdispersion of the "count" data (number of appropriate shocks) and an adjusted intensity rate ratio was calculated for statin use. A total of 676 patients were included, of which statins were used by 65% (329 of 506) of the ischemic and 42% (72 of 170) of the nonischemic groups. Occurrence of appropriate shocks was significantly reduced with statins in ischemic (13.4% vs 20.9%; relative risk 0.64, P = 0.028), but not in the patients with nonischemic cardiomyopathy. Similarly, although use of statins lowered the intensity rate of appropriate shocks in ischemic patients (intensity rate ratio, 0.23; 95% confidence interval, 0.12-0.47), no such benefit was noted in the nonischemic group (intensity rate ratio, 1.27; 95% confidence interval, 0.37-4.40). In conclusion, statins reduced the occurrence and frequency of appropriate shocks for ventricular arrhythmias in ischemic but not in nonischemic cardiomyopathy. Larger, randomized controlled trials are needed to confirm these findings.

  1. Use of Implantable Cardioverter Defibrillators in Heart Failure Patients and Risk of Mortality: A Meta-Analysis

    PubMed Central

    Zhang, Yucong; Li, Kang

    2015-01-01

    Background The purpose of this study was to evaluate the effect of implantable cardioverter defibrillators (ICD) in heart failure (HF) patients compared to pharmacologic/conventional management. Material/Methods We searched PubMed, Embase, and Springer Link Library databases up to February 10th, 2014. Pooled risk ratio (RR) and 95% confidence interval (CI) for the mortality of the patients with HF were collected and calculated in a fixed-effects model or a random-effects model, as appropriate. Summary effect estimates were also stratified by sex and follow-up time. Egger’s regression asymmetry tests were utilized for publication bias detection. Results A total of 7 separate studies including 15 520 patients (10 801 ICD cases and 4719 controls) with HF were considered in the meta-analysis. The overall estimates showed that ICD could statistically significantly reduce the mortality of male (RR=0.73, 95% CI: 0.66–0.80) and female (RR=0.75, 95% CI: 0.63–0.90) patients. In addition, the further stratification subgroup analysis indicated that ICD presented a significant reduction (male: RR=0.72, 95% CI: 0.64–0.81; female: RR=0.69, 95% CI: 0.56–0.85) of mortality after 2–3 years of ICD therapy. The RR (95% CI) effects of mortality after 4–5 years of ICD therapy for males and females were 0.76 (0.51–1.14) and 0.96 (0.68–1.37), respectively. Conclusions This meta-analysis suggests that ICD could reduce HF patient mortality despite the sex difference. PMID:26093516

  2. Efficacy and Limitations of Tachycardia Detection Interval Guided Reprogramming for Reduction of Inappropriate Shock in Implantable Cardioverter-Defibrillator Patients.

    PubMed

    Fujiishi, Tamami; Niwano, Shinichi; Murakami, Masami; Nakamura, Hironori; Igarashi, Tazuru; Ishizue, Naruya; Oikawa, Jun; Kishihara, Jun; Fukaya, Hidehira; Niwano, Hiroe; Ako, Junya

    2016-05-25

    The avoidance of inappropriate shock therapy is an important clinical issue in implantable cardioverter-defibrillator (ICD) patients. We retrospectively analyzed therapeutic events in ICD patients, and the effect of tachycardia detection interval (TDI) and tachycardia cycle length (TCL) guided reprograming on the reduction of inappropriate ICD therapy. The clinical determinants of after reprogramming were also evaluated.A total of 254 consecutive ICD patients were included in the study, and the incidence of antitachycardia therapy was evaluated during the follow-up period of 27.3 ± 18.7 months. When inappropriate antitachycardia therapy appeared, TDI was reprogrammed not to exceed the detected TCL and the patients continued to be followed-up. Various clinical parameters were compared between patients with and without inappropriate ICD therapy. During the initial follow-up period of 18.6 ± 15.6 months, ICD therapy occurred in 127/254 patients (50%) including inappropriate antitachycardia pacing (ATP) (12.9%) and shock (44.35%). Determinants of initial inappropriate therapy were dilated cardiomyopathy (DCM), history of therapeutic hypothermia, and QRS duration. Of the 61 patients with inappropriate therapy, 24 received TCL guided reprogramming. During the additional observation period of 17.0 ± 16.8 months, inappropriate therapy recurred in 5/24 patients (2 ATP, 3 shocks). The determinant of these inappropriate therapy events after reprogramming was the presence of supraventricular tachycardia.By applying simple TCL and TDI guided reprogramming, inappropriate therapy was reduced by 79%. The determinant of inappropriate therapy after reprogramming was the presence of supraventricular tachycardia.

  3. In vitro assessment of the immunity of implantable cardioverter-defibrillators to magnetic fields of 50/60 Hz.

    PubMed

    Katrib, J; Nadi, M; Kourtiche, D; Magne, I; Schmitt, P; Souques, M; Roth, P

    2013-10-01

    Public concern for the compatibility of electromagnetic (EM) sources with active implantable medical devices (AIMD) has prompted the development of new systems that can perform accurate exposure studies. EM field interference with active cardiac implants (e.g. implantable cardioverter-defibrillators (ICDs)) can be critical. This paper describes a magnetic field (MF) exposure system and the method developed for testing the immunity of ICD to continuous-wave MFs. The MFs were created by Helmholtz coils, housed in a Faraday cage. The coils were able to produce highly uniform MFs up to 4000 µT at 50 Hz and 3900 µT at 60 Hz, within the test space. Four ICDs were tested. No dysfunctions were found in the generated MFs. These results confirm that the tested ICDs were immune to low frequency MFs.

  4. Development and testing of an intervention to improve outcomes for partners following receipt of an implantable cardioverter defibrillator in the patient.

    PubMed

    Dougherty, Cynthia M; Thompson, Elaine A; Kudenchuk, Peter J

    2012-01-01

    The purpose of this article is to describe 3 foundational studies and how their results were used to formulate, design, and test a novel partner intervention for implementation in the immediate post-ICD (implantable cardioverter defibrillator) period after returning home. Nursing's expanding role into chronic illness management in the creation of evidence-based practice is highlighted. A randomized clinical trial comparing 2 intervention programs is being conducted with patients who receive an ICD for the first time and their intimate partners. Primary outcomes are physical functioning, psychological adjustment, relationship impact, and health care utilization.

  5. Nurse- and peer-led self-management programme for patients with an implantable cardioverter defibrillator; a feasibility study

    PubMed Central

    Smeulders, Esther STF; van Haastregt, Jolanda CM; Dijkman-Domanska, Barbara K; van Hoef, Elisabeth FM; van Eijk, Jacques ThM; Kempen, Gertrudis IJM

    2007-01-01

    Background The prevalence of cardiovascular disease is increasing. Improved treatment options increase survival after an acute myocardial infarction or sudden cardiac arrest, although patients often have difficulty adjusting and regaining control in daily life. In particular, patients who received an implantable cardioverter defibrillator (ICD) experience physical and psychological problems. Interventions to enhance perceived control and acceptance of the device are therefore necessary. This paper describes a small-scale study to explore the feasibility and the possible benefits of a structured nurse- and peer-led self-management programme ('Chronic Disease Self-Management Program' – CDSMP) among ICD patients. Methods Ten male ICD patients (mean age = 65.5 years) participated in a group programme, consisting of six sessions, led by a team consisting of a nurse specialist and a patient with cardiovascular disease. Programme feasibility was evaluated among patients and leaders by measuring performance of the intervention according to protocol, attendance and adherence of the participating ICD patients, and patients' and leaders' opinions about the programme. In addition, before and directly after attending the intervention, programme benefits (e.g. perceived control, symptoms of anxiety and depression, and quality of life) were assessed. Results The programme was conducted largely according to protocol. Eight patients attended at least four sessions, and adherence ranged from good to very good. On average, the patients reported to have benefited very much from the programme, which they gave an overall report mark of 8.4. The leaders considered the programme feasible as well. Furthermore, improvements were identified for general self-efficacy expectancies, symptoms of anxiety, physical functioning, social functioning, role limitations due to physical problems, and pain. Conclusion This study suggests that a self-management programme led by a team consisting of a

  6. Results of ENHANCED Implantable Cardioverter Defibrillator Programming to Reduce Therapies and Improve Quality of Life (from the ENHANCED-ICD Study).

    PubMed

    Mastenbroek, Mirjam H; Pedersen, Susanne S; van der Tweel, Ingeborg; Doevendans, Pieter A; Meine, Mathias

    2016-02-15

    Novel implantable cardioverter defibrillator (ICD) discrimination algorithms and programming strategies have significantly reduced the incidence of inappropriate shocks, but there are still gains to be made with respect to reducing appropriate but unnecessary antitachycardia pacing (ATP) and shocks. We examined whether programming a number of intervals to detect (NID) of 60/80 for ventricular tachyarrhythmia (VT)/ventricular fibrillation (VF) detection was safe and the impact of this strategy on (1) adverse events related to ICD shocks and syncopal events; (2) ATPs/shocks; and (3) patient-reported outcomes. The "ENHANCED Implantable Cardioverter Defibrillator programming to reduce therapies and improve quality of life" study (ENHANCED-ICD study) was a prospective, safety-monitoring study enrolling 60 primary and secondary prevention patients at the University Medical Center Utrecht. Patients implanted with any type of ICD with SmartShock technology and aged 18 to 80 years were eligible to participate. In all patients, a prolonged NID 60/80 was programmed. The cycle length for VT/fast VT/VF was 360/330/240 ms, respectively. Programming a NID 60/80 proved safe for ICD patients. Because of the new programming strategy, unnecessary ICD therapy was prevented in 10% of ENHANCED-ICD patients during a median follow-up period of 1.3 years. With respect to patient-reported outcomes, levels of distress were highest and perceived health status lowest at the time of implantation, which both gradually improved during follow-up. In conclusion, the ENHANCED-ICD study demonstrates that programming a NID 60/80 for VT/VF detection is safe for ICD patients and does not negatively impact their quality of life.

  7. The Automatic Implantable Cardioverter Defibrillator in Critical Care and Emergency Room Settings

    DTIC Science & Technology

    1991-01-01

    possibly painful, but not dangerous to the rescuer ( American Heart Association , 1987). The wearing of rubber examination gloves can insulate the...AACN position statements. Newport Beach, CA: Author. American Heart Association . (1987). Textbook of advanced cardiac life support (3rd ed.). Dallas...76 Appendix A Paddle A: Place right of upper sternum and below right clavicle ( American Heart Association , 1987). Paddle B: Place left of left nipple

  8. Large Controlled Observational Study on Remote Monitoring of Pacemakers and Implantable Cardiac Defibrillators: A Clinical, Economic, and Organizational Evaluation

    PubMed Central

    2016-01-01

    Background Patients with implantable devices such as pacemakers (PMs) and implantable cardiac defibrillators (ICDs) should be followed up every 3–12 months, which traditionally required in-clinic visits. Innovative devices allow data transmission and technical or medical alerts to be sent from the patient's home to the physician (remote monitoring). A number of studies have shown its effectiveness in timely detection and management of both clinical and technical events, and endorsed its adoption. Unfortunately, in daily practice, remote monitoring has been implemented in uncoordinated and rather fragmented ways, calling for a more strategic approach. Objective The objective of the study was to analyze the impact of remote monitoring for PM and ICD in a “real world” context compared with in-clinic follow-up. The evaluation focuses on how this service is carried out by Local Health Authorities, the impact on the cardiology unit and the health system, and organizational features promoting or hindering its effectiveness and efficiency. Methods A multi-center, multi-vendor, controlled, observational, prospective study was conducted to analyze the impact of remote monitoring implementation. A total of 2101 patients were enrolled in the study: 1871 patients were followed through remote monitoring of PM/ICD (I-group) and 230 through in-clinic visits (U-group). The follow-up period was 12 months. Results In-clinic device follow-ups and cardiac visits were significantly lower in the I-group compared with the U-group, respectively: PM, I-group = 0.43, U-group = 1.07, P<.001; ICD, I-group = 0.98, U-group = 2.14, P<.001. PM, I-group = 0.37, U-group = 0.85, P<.001; ICD, I-group = 1.58, U-group = 1.69, P=.01. Hospitalizations for any cause were significantly lower in the I-group for PM patients only (I-group = 0.37, U-group = 0.50, P=.005). There were no significant differences regarding use of the emergency department for both PM and ICD patients. In the I-group, 0.30 (PM

  9. The mismatch between patient life expectancy and the service life of implantable devices in current cardioverter-defibrillator therapy: a call for larger device batteries.

    PubMed

    Neuzner, Jörg

    2015-06-01

    In 2005, Bob Hauser published a paper in the Journal of the American College of Cardiology entitled "The growing mismatch between patient longevity and the service life of Implantable Cardioverter-Defibrillators". Now, nearly a decade later, I would like to perform a second look on the problem of a mismatching between ICD device service life and the survival of ICD recipients. Since 2005, the demographics of the ICD population has changed significantly. Primary prevention has become the dominant indication in defibrillator therapy and device implantation is indicated more and more in earlier stages of cardiac diseases. In former larger scale ICD trials, the patient average 5-year survival probability was in a range of 68-71%; in newer CRT-D trials in a range of 72-88%. Due to a progressively widened ICD indication and implantation preferentially performed in patients with better life expectancy, the problem of inadequate device service life is of growing importance. The early days of defibrillator therapy started with a generator volume of 145 ccm and a device service life <18 months. In this early period, the device miniaturization and extension of service life were similar challenges for the technicians. Today, we have reached a formerly unexpected extent of device miniaturization. However, technologic improvements were often preferentially translated in further device miniaturization and not in prolonging device service life. In his analysis, Bob Hauser reported a prolonged device service life of 2.3 years in ICD models with a larger battery capacity of 0.54 up to 0.69 Ah. Between 2008 and 2014, several studies had been published on the problem of ICD longevity in clinical scenarios. These analyses included "older" and currently used single chamber, dual chamber and CRT devices. The reported average 5-year device service life ranged from 0 to 75%. Assuming today technology, larger battery capacities will only result in minimal increase in device volume. Selected

  10. [Case with Emery-Dreifuss muscular dystrophy diagnosed forty-two years after onset and implanted with a cardiac resynchronization therapy defibrillator].

    PubMed

    Sakiyama, Yoshio; Watanabe, Eri; Otsuka, Mieko; Hirahara, Taishi; Momomura, Shinichi; Hayashi, Yukiko

    2014-01-01

    The patient was a 53-year-old male. He showed steppage gait at the age of 11 and equinus foot at 13. He walked unaided with shoe-insoles to support his heels. Atrial fibrillation and cardiac hypertrophy were found in his 30s, and ventricular tachycardia (VT) was observed at the age of 48. Electrophysiological studies were performed, but VT was not sustained, symptomatic, or showed signs of infra-Hisian block, and a pacemaker was not indicated. At 53, he was introduced to a neurologist because of tetraplegia after the first episode of syncope. A spinal MR showed ossification of posterior longitudinal ligament (OPLL) and central cervical cord injury. Furthermore, he presented not only contracture in his shoulder, elbow, and ankles but also atrophy in his scapulohumeral and gastrocnemius muscles. In accordance with a diagnosis of Emery-Dreifuss muscular dystrophy (EDMD), provocative testing of VT was carried out, and a cardiac resynchronization therapy defibrillator (CRT-D) was implanted. Later, a mutation analysis of the LMNA gene disclosed a known missense mutation of p.Arg377His, and we diagnosed him as EDMD2 (laminopathy). Contractures could be the clue to diagnose EDMD and indicate the need for pacemakers and defibrillators in patients with cardiac conduction disorders.

  11. Implantable acoustic-beacon automatic fish-tracking system

    NASA Technical Reports Server (NTRS)

    Mayhue, R. J.; Lovelady, R. W.; Ferguson, R. L.; Richards, C. E.

    1977-01-01

    A portable automatic fish tracking system was developed for monitoring the two dimensional movements of small fish within fixed areas of estuarine waters and lakes. By using the miniature pinger previously developed for this application, prototype tests of the system were conducted in the York River near the Virginia Institute of Marine Science with two underwater listening stations. Results from these tests showed that the tracking system could position the miniature pinger signals to within + or - 2.5 deg and + or - 135 m at ranges up to 2.5 km. The pingers were implanted in small fish and were successfully tracked at comparable ranges. No changes in either fish behavior or pinger performance were observed as a result of the implantation. Based on results from these prototype tests, it is concluded that the now commercially available system provides an effective approach to underwater tracking of small fish within a fixed area of interest.

  12. Implanted Defibrillators Benefit Seniors

    MedlinePlus

    ... in the Journal of the American College of Cardiology . More than 65 percent of the patients were ... Cardiovascular Data Registry at the American College of Cardiology. Still, "I was surprised to see the survival ...

  13. Implantable cardioverter defibrillator - discharge

    MedlinePlus

    ... DL, Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine . 10th ed. Philadelphia, PA: Elsevier ... Updated by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, ...

  14. Implantable Cardioverter Defibrillator

    MedlinePlus

    ... Intramural Research Research Resources Research Meeting Summaries Technology Transfer Clinical Trials What Are Clinical Trials? Children & Clinical ... rhythm in your ventricles, it will use low-energy electrical pulses to restore a normal rhythm. If ...

  15. Implantable Cardioverter Defibrillator

    MedlinePlus

    ... under the skin. Like pacemakers , ICDs contain a generator containing a computer, battery, and wires called “leads” ... while the other end is connected to the generator. The battery in the generator lasts 5-8 ...

  16. A Young Man Presenting with Pleuritic Chest Pain and Fever after Electrophysiological Study and Implantable Cardioverter-Defibrillator Placement: Diagnostic Difficulties and Value of Bedside Thoracic Sonography

    PubMed Central

    Faraone, Antonio; Fortini, Alberto

    2015-01-01

    We describe the case of a 23-year-old man presenting with recurrent pleuritic chest pain and prolonged fever after electrophysiology testing and placement of an implantable cardioverter-defibrillator because of a suspected arrhythmogenic right ventricular dysplasia. The clinical suspicion was initially directed toward pneumonia with pleural effusion and later toward an infection of the cardiac device complicated by septic pulmonary embolism. The definitive diagnosis of pulmonary embolism and infarction was suggested by a point-of-care thoracic sonography, performed at the bedside by a clinician caring for the patient, and then confirmed by contrast enhanced computed tomography, which also showed thrombosis of the left iliofemoral vein, site of percutaneous puncture for cardiac catheterization. Prolonged fever was attributable to a concomitant Epstein-Barr virus primary infection that acted as confounding factor. The present report confirms the value of bedside thoracic sonography in the diagnostic evaluation of patients with nonspecific respiratory symptoms. PMID:26576159

  17. Primary Prevention of Sudden Cardiac Death in Adults with Transposition of the Great Arteries: A Review of Implantable Cardioverter-Defibrillator Placement

    PubMed Central

    Cedars, Ari M.

    2015-01-01

    Transposition of the great arteries encompasses a set of structural congenital cardiac lesions that has in common ventriculoarterial discordance. Primarily because of advances in medical and surgical care, an increasing number of children born with this anomaly are surviving into adulthood. Depending upon the subtype of lesion or the particular corrective surgery that the patient might have undergone, this group of adult congenital heart disease patients constitutes a relatively new population with unique medical sequelae. Among the more common and difficult to manage are cardiac arrhythmias and other sequelae that can lead to sudden cardiac death. To date, the question of whether implantable cardioverter-defibrillators should be placed in this cohort as a preventive measure to abort sudden death has largely gone unanswered. Therefore, we review the available literature surrounding this issue. PMID:26413012

  18. A Young Man Presenting with Pleuritic Chest Pain and Fever after Electrophysiological Study and Implantable Cardioverter-Defibrillator Placement: Diagnostic Difficulties and Value of Bedside Thoracic Sonography.

    PubMed

    Faraone, Antonio; Fortini, Alberto

    2015-01-01

    We describe the case of a 23-year-old man presenting with recurrent pleuritic chest pain and prolonged fever after electrophysiology testing and placement of an implantable cardioverter-defibrillator because of a suspected arrhythmogenic right ventricular dysplasia. The clinical suspicion was initially directed toward pneumonia with pleural effusion and later toward an infection of the cardiac device complicated by septic pulmonary embolism. The definitive diagnosis of pulmonary embolism and infarction was suggested by a point-of-care thoracic sonography, performed at the bedside by a clinician caring for the patient, and then confirmed by contrast enhanced computed tomography, which also showed thrombosis of the left iliofemoral vein, site of percutaneous puncture for cardiac catheterization. Prolonged fever was attributable to a concomitant Epstein-Barr virus primary infection that acted as confounding factor. The present report confirms the value of bedside thoracic sonography in the diagnostic evaluation of patients with nonspecific respiratory symptoms.

  19. Surgery for postinfarction ventricular tachycardia in the pre-implantable cardioverter defibrillator era: early and long term outcomes in 100 consecutive patients

    PubMed Central

    Bourke, J; Campbell, R; McComb, J; Furniss, S; Doig, J; Hilton, C

    1999-01-01

    OBJECTIVE—To report outcome following surgery for postinfarction ventricular tachycardia undertaken in patients before the use of implantable defibrillators.
DESIGN—A retrospective review, with uniform patient selection criteria and surgical and mapping strategy throughout. Complete follow up. Long term death notification by OPCS (Office of Population Censuses and Statistics) registration.
SETTING—Tertiary referral centre for arrhythmia management.
PATIENTS—100 consecutive postinfarction patients who underwent map guided endocardial resection at this hospital in the period 1981-91 for drug refractory ventricular tachyarrhythmias.
RESULTS—Emergency surgery was required for intractable arrhythmias in 28 patients, and 32 had surgery within eight weeks of infarction ("early"). Surgery comprised endocardial resections in all, aneurysmectomy in 57, cryoablations in 26, and antiarrhythmic ventriculotomies in 11. Twenty five patients died < 30 days after surgery, 21 of cardiac failure. This high mortality reflects the type of patients included in the series. Only 12 received antiarrhythmic drugs after surgery. Perioperative mortality was related to preoperative left ventricular function and the context of surgery. Mortality rates for elective surgery more than eight weeks after infarction, early surgery, emergency surgery, and early emergency surgery were 18%, 31%, 46%, and 50%, respectively. Actuarial survival rates at one, three, five, and 10 years after surgery were 66%, 62%, 57%, and 35%.
CONCLUSIONS—Surgery offers arrhythmia abolition at a risk proportional to the patient's preoperative risk of death from ventricular arrhythmias. The long term follow up results suggest a continuing role for surgery in selected patients even in the era of catheter ablation and implantable defibrillators.


Keywords: arrhythmias; myocardial infarction; surgical management PMID:10409528

  20. Is there any indication for an intracardiac defibrillator for the treatment of atrial fibrillation?

    PubMed

    Lévy, S; Richard, P

    1994-11-01

    The experience gained using intracardiac cardioverter defibrillators for the treatment of ventricular arrhythmias has prompted the development of an automatic atrial defibrillator capable of detecting and automatically terminating atrial fibrillation (AF). Experimental studies in sheep have shown that it is possible to terminate AF with energies ranging from < 1 to 7 joules [J], using biphasic shocks. The best electrode configuration using intracardiac catheters and/or a subcutaneous patch was two catheters, one in the right atrium and the other in the coronary sinus. Current studies in man focus on the answers to three questions. First, can the experimental results of atrial defibrillation derived from healthy anesthetized sheep without spontaneous AF be extrapolated to AF in man with areas of fibrosis within the atria and/or underlying heart disease in 80% of cases? Preliminary studies in man suggest that cardioversion of AF of short duration is feasible using a mean energy of 2 J. Second, are these energies well tolerated in an awake nonsedated patient? Energies < 1 J were well tolerated, but pain resulting from higher energies needs further investigation. Third, is low-energy atrial defibrillation safe, i.e., is there a risk of ventricular arrhythmias induced by an atrial shock? Experimental results in sheep have shown that the risk of R wave synchronized shock to induce ventricular arrhythmias was only present when the preceding RR interval was shorter than 300 msec. The risk of proarrhythmia in man is undergoing evaluation and must be sufficiently low (< 0.1) before sanctioning implantation of a stand-alone (without associated ventricular defibrillator) automatic atrial defibrillator. Preliminary data on 1212 shocks showed no proarrhythmia.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Appropriate evaluation and treatment of heart failure patients after implantable cardioverter-defibrillator discharge: time to go beyond the initial shock.

    PubMed

    Mishkin, Joseph D; Saxonhouse, Sherry J; Woo, Gregory W; Burkart, Thomas A; Miles, William M; Conti, Jamie B; Schofield, Richard S; Sears, Samuel F; Aranda, Juan M

    2009-11-24

    Multiple clinical trials support the use of implantable cardioverter-defibrillators (ICDs) for prevention of sudden cardiac death in patients with heart failure (HF). Unfortunately, several complicating issues have arisen from the universal use of ICDs in HF patients. An estimated 20% to 35% of HF patients who receive an ICD for primary prevention will experience an appropriate shock within 1 to 3 years of implant, and one-third of patients will experience an inappropriate shock. An ICD shock is associated with a 2- to 5-fold increase in mortality, with the most common cause being progressive HF. The median time from initial ICD shock to death ranges from 168 to 294 days depending on HF etiology and the appropriateness of the ICD therapy. Despite this prognosis, current guidelines do not provide a clear stepwise approach to managing these high-risk patients. An ICD shock increases HF event risk and should trigger a thorough evaluation to determine the etiology of the shock and guide subsequent therapeutic interventions. Several combinations of pharmacologic and device-based interventions such as adding amiodarone to baseline beta-blocker therapy, adjusting ICD sensitivity, and employing antitachycardia pacing may reduce future appropriate and inappropriate shocks. Aggressive HF surveillance and management is required after an ICD shock, as the risk of sudden cardiac death is transformed to an increased HF event risk.

  2. Effectiveness of Implantable Cardioverter-Defibrillator Therapy for Heart Failure Patients according to Ischemic or Non-Ischemic Etiology in Korea

    PubMed Central

    Park, Kyu-Hwan; Lee, Chan-Hee; Jung, Byung Chun; Cho, Yongkeun; Bae, Myung Hwan; Kim, Yoon-Nyun; Park, Hyoung-Seob; Han, Seongwook; Lee, Young Soo; Hyun, Dae-Woo; Kim, Jun; Kim, Dae Kyeong; Cha, Tae-Jun

    2017-01-01

    Background and Objectives This study was performed to describe clinical characteristics of patients with left ventriculars (LV) dysfunction and implantable cardioverter-defibrillator (ICD), and to evaluate the effect of ICD therapy on survival in Yeongnam province of Korea. Subjects and Methods From a community-based device registry (9 centers, Yeongnam province, from November 1999 to September 2012), 146 patients with LV dysfunction and an ICD implanted for primary or secondary prophylaxis, were analyzed. The patients were divided into two groups, based on the etiology (73 with ischemic cardiomyopathy and 73 with non-ischemic cardiomyopathy), and indication for the device implantation (36 for primary prevention and 110 for secondary prevention). The cumulative first shock rate, all cause death, and type and mode of death, were determined according to the etiology and indication. Results Over a mean follow-up of 3.5 years, the overall ICD shock rate was about 39.0%. ICD shock therapy was significantly more frequent in the secondary prevention group (46.4% vs. 16.7%, p=0.002). The cumulative probability of a first appropriate shock was higher in the secondary prevention group (p=0.015). There was no significant difference in the all-cause death, cardiac death, and mode of death between the groups according to the etiology and indication. Conclusion Studies from this multicenter regional registry data shows that in both ischemic and non-ischemic cardiomyopathy patients, the ICD shock therapy rate was higher in the secondary prevention group than primary prevention group. PMID:28154594

  3. Usefulness of cardiac resynchronisation therapy devices and implantable cardioverter defibrillators in the treatment of heart failure due to severe systolic dysfunction: systematic review of clinical trials and network meta-analysis

    PubMed Central

    García García, M A; Rosero Arenas, M A; Ruiz Granell, R; Chorro Gascó, F J; Martínez Cornejo, A

    2016-01-01

    Aim To assess the effectiveness of cardiac resynchronisation therapy (CRT), implantable cardioverter defibrillator (ICD) therapy, and the combination of these devices (CRT+ICD) in adult patients with left ventricular dysfunction and symptomatic heart failure. Methods A comprehensive systematic review of randomised clinical trials was conducted. Several electronic databases (PubMed, Embase, Ovid, Cochrane, ClinicalTrials.gov) were reviewed. The mortality rates between treatments were compared. A network was established comparing the various options, and direct, indirect and mixed comparisons were made using multivariate meta-regression. The degree of clinical and statistical homogeneity was assessed. Results 43 trials involving 13 017 patients were reviewed. Resynchronisation therapy, defibrillators, and combined devices (CRT+ICD) are clearly beneficial compared to optimal medical treatment, showing clear benefit in all of these cases. In a theoretical order of efficiency, the first option is combined therapy (CRT+ICD), the second is CRT, and the third is defibrillator implantation (ICD). Given the observational nature of these comparisons, and the importance of the overlapping CIs, we cannot state that the combined option (CRT+ICD) offers superior survival benefit compared to the other two options. Conclusions The combined option of CRT+ICD seems to be better than the option of CRT alone, although no clear improvement in survival was found for the combined option. It would be advisable to perform a direct comparative study of these two options. PMID:27326223

  4. Educational and psychological interventions to improve outcomes for recipients of implantable cardioverter defibrillators and their families: a scientific statement from the American Heart Association.

    PubMed

    Dunbar, Sandra B; Dougherty, Cynthia M; Sears, Samuel F; Carroll, Diane L; Goldstein, Nathan E; Mark, Daniel B; McDaniel, George; Pressler, Susan J; Schron, Eleanor; Wang, Paul; Zeigler, Vicki L

    2012-10-23

    Significant mortality benefits have been documented in recipients of implantable cardioverter defibrillators (ICDs); however, the psychosocial distress created by the underlying arrhythmia and its potential treatments in patients and family members may be underappreciated by clinical care teams. The disentanglement of cardiac disease and device-related concerns is difficult. The majority of ICD patients and families successfully adjust to the ICD, but optimal care pathways may require additional psychosocial attention to all ICD patients and particularly those experiencing psychosocial distress. This state-of-the-science report was developed on the basis of an analysis and critique of existing science to (1) describe the psychological and quality-of-life outcomes after receipt of an ICD and describe related factors, such as patient characteristics; (2) describe the concerns and educational/informational needs of ICD patients and their family members; (3) outline the evidence that supports interventions for improving educational and psychological outcomes for ICD patients; (4) provide recommendations for clinical approaches for improving patient outcomes; and (5) identify priorities for future research in this area. The ultimate goal of this statement is to improve the precision of identification and care of psychosocial distress in ICD patients to maximize the derived benefit of the ICD.

  5. Automatic coregistration of volumetric images based on implanted fiducial markers.

    PubMed

    Koch, Martin; Maltz, Jonathan S; Belongie, Serge J; Gangadharan, Bijumon; Bose, Supratik; Shukla, Himanshu; Bani-Hashemi, Ali R

    2008-10-01

    The accurate delivery of external beam radiation therapy is often facilitated through the implantation of radio-opaque fiducial markers (gold seeds). Before the delivery of each treatment fraction, seed positions can be determined via low dose volumetric imaging. By registering these seed locations with the corresponding locations in the previously acquired treatment planning computed tomographic (CT) scan, it is possible to adjust the patient position so that seed displacement is accommodated. The authors present an unsupervised automatic algorithm that identifies seeds in both planning and pretreatment images and subsequently determines a rigid geometric transformation between the two sets. The algorithm is applied to the imaging series of ten prostate cancer patients. Each test series is comprised of a single multislice planning CT and multiple megavoltage conebeam (MVCB) images. Each MVCB dataset is obtained immediately prior to a subsequent treatment session. Seed locations were determined to within 1 mm with an accuracy of 97 +/- 6.1% for datasets obtained by application of a mean imaging dose of 3.5 cGy per study. False positives occurred in three separate instances, but only when datasets were obtained at imaging doses too low to enable fiducial resolution by a human operator, or when the prostate gland had undergone large displacement or significant deformation. The registration procedure requires under nine seconds of computation time on a typical contemporary computer workstation.

  6. Infarct tissue characterization in implantable cardioverter-defibrillator recipients for primary versus secondary prevention following myocardial infarction: a study with contrast-enhancement cardiovascular magnetic resonance imaging.

    PubMed

    Olimulder, Marlon A G M; Kraaier, Karin; Galjee, Michel A; Scholten, Marcoen F; van Es, Jan; Wagenaar, Lodewijk J; van der Palen, Job; von Birgelen, Clemens

    2013-01-01

    Knowledge about potential differences in infarct tissue characteristics between patients with prior life-threatening ventricular arrhythmia versus patients receiving prophylactic implantable cardioverter-defibrillator (ICD) might help to improve the current risk stratification in myocardial infarction (MI) patients who are considered for ICD implantation. In a consecutive series of (ICD) recipients for primary and secondary prevention following MI, we used contrast-enhanced (CE) cardiovascular magnetic resonance (CMR) imaging to evaluate differences in infarct tissue characteristics. Cine-CMR measurements included left ventricular end-diastolic and end-systolic volumes (EDV, ESV), left ventricular ejection fraction (LVEF), wall motion score index (WMSI), and mass. CE-CMR images were analyzed for core, peri, and total infarct size, infarct localization (according to coronary artery territory), and transmural extent. In this study, 95 ICD recipients were included. In the primary prevention group (n = 66), LVEF was lower (23 ± 9% vs. 31 ± 14%; P < 0.01), ESV and WMSI were higher (223 ± 75 ml vs. 184 ± 97 ml, P = 0.04, and 1.89 ± 0.52 vs. 1.47 ± 0.68; P < 0.01), and anterior infarct localization was more frequent (P = 0.02) than in the secondary prevention group (n = 29). There were no differences in infarct tissue characteristics between patients treated for primary versus secondary prevention (P > 0.6 for all). During 21 ± 9 months of follow-up, 3 (5%) patients in the primary prevention group and 9 (31%) in the secondary prevention group experienced appropriate ICD therapy for treatment of ventricular arrhythmia (P < 0.01). There was no difference in infarct tissue characteristics between recipients of ICD for primary versus secondary prevention, while the secondary prevention group showed a higher frequency of applied ICD therapy for ventricular arrhythmia.

  7. Comparison of the Effects of High-Energy Photon Beam Irradiation (10 and 18 MV) on 2 Types of Implantable Cardioverter-Defibrillators

    SciTech Connect

    Hashii, Haruko; Hashimoto, Takayuki; Okawa, Ayako; Shida, Koichi; Isobe, Tomonori; Hanmura, Masahiro; Nishimura, Tetsuo; Aonuma, Kazutaka; Sakae, Takeji; Sakurai, Hideyuki

    2013-03-01

    Purpose: Radiation therapy for cancer may be required for patients with implantable cardiac devices. However, the influence of secondary neutrons or scattered irradiation from high-energy photons (≥10 MV) on implantable cardioverter-defibrillators (ICDs) is unclear. This study was performed to examine this issue in 2 ICD models. Methods and Materials: ICDs were positioned around a water phantom under conditions simulating clinical radiation therapy. The ICDs were not irradiated directly. A control ICD was positioned 140 cm from the irradiation isocenter. Fractional irradiation was performed with 18-MV and 10-MV photon beams to give cumulative in-field doses of 600 Gy and 1600 Gy, respectively. Errors were checked after each fraction. Soft errors were defined as severe (change to safety back-up mode), moderate (memory interference, no changes in device parameters), and minor (slight memory change, undetectable by computer). Results: Hard errors were not observed. For the older ICD model, the incidences of severe, moderate, and minor soft errors at 18 MV were 0.75, 0.5, and 0.83/50 Gy at the isocenter. The corresponding data for 10 MV were 0.094, 0.063, and 0 /50 Gy. For the newer ICD model at 18 MV, these data were 0.083, 2.3, and 5.8 /50 Gy. Moderate and minor errors occurred at 18 MV in control ICDs placed 140 cm from the isocenter. The error incidences were 0, 1, and 0 /600 Gy at the isocenter for the newer model, and 0, 1, and 6 /600Gy for the older model. At 10 MV, no errors occurred in control ICDs. Conclusions: ICD errors occurred more frequently at 18 MV irradiation, which suggests that the errors were mainly caused by secondary neutrons. Soft errors of ICDs were observed with high energy photon beams, but most were not critical in the newer model. These errors may occur even when the device is far from the irradiation field.

  8. Gender Differences in Appropriate Shocks and Mortality among Patients with Primary Prophylactic Implantable Cardioverter-Defibrillators: Systematic Review and Meta-Analysis

    PubMed Central

    Conen, David; Arendacká, Barbora; Röver, Christian; Bergau, Leonard; Munoz, Pascal; Wijers, Sofieke; Sticherling, Christian; Zabel, Markus; Friede, Tim

    2016-01-01

    Background Some but not all prior studies have shown that women receiving a primary prophylactic implantable cardioverter defibrillator (ICD) have a lower risk of death and appropriate shocks than men. Purpose To evaluate the effect of gender on the risk of appropriate shock, all-cause mortality and inappropriate shock in contemporary studies of patients receiving a primary prophylactic ICD. Data Source PubMed, LIVIVO, Cochrane CENTRAL between 2010 and 2016. Study Selection Studies providing at least 1 gender-specific risk estimate for the outcomes of interest. Data Extraction Abstracts were screened independently for potentially eligible studies for inclusion. Thereby each abstract was reviewed by at least two authors. Data Synthesis Out of 680 abstracts retained by our search strategy, 20 studies including 46’657 patients had gender-specific information on at least one of the relevant endpoints. Mean age across the individual studies varied between 58 and 69 years. The proportion of women enrolled ranged from 10% to 30%. Across 6 available studies, women had a significantly lower risk of first appropriate shock compared with men (pooled multivariable adjusted hazard ratio 0.62 (95% CI [0.44; 0.88]). Across 14 studies reporting multivariable adjusted gender-specific hazard ratio estimates for all-cause mortality, women had a lower risk of death than men (pooled hazard ratio 0.75 (95% CI [0.66; 0.86]). There was no statistically significant difference for the incidence of first inappropriate shocks (3 studies, pooled hazard ratio 0.99 (95% CI [0.56; 1.73]). Limitations Individual patient data were not available for most studies. Conclusion In this large contemporary meta-analysis, women had a significantly lower risk of appropriate shocks and death than men, but a similar risk of inappropriate shocks. These data may help to select patients who benefit from primary prophylactic ICD implantation. PMID:27618617

  9. Effect of angiotensin-converting enzyme inhibitors and receptor blockers on appropriate implantable cardiac defibrillator shock in patients with severe systolic heart failure (from the GRADE Multicenter Study).

    PubMed

    AlJaroudi, Wael A; Refaat, Marwan M; Habib, Robert H; Al-Shaar, Laila; Singh, Madhurmeet; Gutmann, Rebecca; Bloom, Heather L; Dudley, Samuel C; Ellinor, Patrick T; Saba, Samir F; Shalaby, Alaa A; Weiss, Raul; McNamara, Dennis M; Halder, Indrani; London, Barry

    2015-04-01

    Sudden cardiac death (SCD) is a leading cause of mortality in patients with cardiomyopathy. Although angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARBs) decrease cardiac mortality in these cohorts, their role in preventing SCD has not been well established. We sought to determine whether the use of ACEi or ARB in patients with cardiomyopathy is associated with a lower incidence of appropriate implantable cardiac defibrillator (ICD) shocks in the Genetic Risk Assessment of Defibrillator Events study that included subjects with an ejection fraction of ≤30% and ICDs. Treatment with ACEi/ARB versus no-ACEi/ARB was physician dependent. There were 1,509 patients (mean age [SD] 63 [12] years, 80% men, mean [SD] EF 21% [6%]) with 1,213 (80%) on ACEi/ARB and 296 (20%) not on ACEi/ARB. We identified 574 propensity-matched patients (287 in each group). After a mean (SD) of 2.5 (1.9) years, there were 334 (22%) appropriate shocks in the entire cohort. The use of ACEi/ARB was associated with lower incidence of shocks at 1, 3, and 5 years in the matched cohort (7.7%, 16.7%, and 18.5% vs 13.2%, 27.5%, and 32.0%; RR = 0.61 [0.43 to 0.86]; p = 0.005). Among patients with glomerular filtration rate (GFR) >60 and 30 to 60 ml/min/1.73 m(2), those on no-ACEi/ARB were at 45% and 77% increased risk of ICD shock compared with those on ACEi/ARB, respectively. ACEi/ARB were associated with significant lower incidence of appropriate ICD shock in patients with cardiomyopathy and GFR ≥30 ml/min/1.73 m(2) and with neutral effect in those with GFR <30 ml/min/1.73 m(2).

  10. Automatic frequency controller for power amplifiers used in bio-implanted applications: issues and challenges.

    PubMed

    Hannan, Mahammad A; Hussein, Hussein A; Mutashar, Saad; Samad, Salina A; Hussain, Aini

    2014-12-11

    With the development of communication technologies, the use of wireless systems in biomedical implanted devices has become very useful. Bio-implantable devices are electronic devices which are used for treatment and monitoring brain implants, pacemakers, cochlear implants, retinal implants and so on. The inductive coupling link is used to transmit power and data between the primary and secondary sides of the biomedical implanted system, in which efficient power amplifier is very much needed to ensure the best data transmission rates and low power losses. However, the efficiency of the implanted devices depends on the circuit design, controller, load variation, changes of radio frequency coil's mutual displacement and coupling coefficients. This paper provides a comprehensive survey on various power amplifier classes and their characteristics, efficiency and controller techniques that have been used in bio-implants. The automatic frequency controller used in biomedical implants such as gate drive switching control, closed loop power control, voltage controlled oscillator, capacitor control and microcontroller frequency control have been explained. Most of these techniques keep the resonance frequency stable in transcutaneous power transfer between the external coil and the coil implanted inside the body. Detailed information including carrier frequency, power efficiency, coils displacement, power consumption, supplied voltage and CMOS chip for the controllers techniques are investigated and summarized in the provided tables. From the rigorous review, it is observed that the existing automatic frequency controller technologies are more or less can capable of performing well in the implant devices; however, the systems are still not up to the mark. Accordingly, current challenges and problems of the typical automatic frequency controller techniques for power amplifiers are illustrated, with a brief suggestions and discussion section concerning the progress of

  11. Automatic Frequency Controller for Power Amplifiers Used in Bio-Implanted Applications: Issues and Challenges

    PubMed Central

    Hannan, Mahammad A.; Hussein, Hussein A.; Mutashar, Saad; Samad, Salina A.; Hussain, Aini

    2014-01-01

    With the development of communication technologies, the use of wireless systems in biomedical implanted devices has become very useful. Bio-implantable devices are electronic devices which are used for treatment and monitoring brain implants, pacemakers, cochlear implants, retinal implants and so on. The inductive coupling link is used to transmit power and data between the primary and secondary sides of the biomedical implanted system, in which efficient power amplifier is very much needed to ensure the best data transmission rates and low power losses. However, the efficiency of the implanted devices depends on the circuit design, controller, load variation, changes of radio frequency coil's mutual displacement and coupling coefficients. This paper provides a comprehensive survey on various power amplifier classes and their characteristics, efficiency and controller techniques that have been used in bio-implants. The automatic frequency controller used in biomedical implants such as gate drive switching control, closed loop power control, voltage controlled oscillator, capacitor control and microcontroller frequency control have been explained. Most of these techniques keep the resonance frequency stable in transcutaneous power transfer between the external coil and the coil implanted inside the body. Detailed information including carrier frequency, power efficiency, coils displacement, power consumption, supplied voltage and CMOS chip for the controllers techniques are investigated and summarized in the provided tables. From the rigorous review, it is observed that the existing automatic frequency controller technologies are more or less can capable of performing well in the implant devices; however, the systems are still not up to the mark. Accordingly, current challenges and problems of the typical automatic frequency controller techniques for power amplifiers are illustrated, with a brief suggestions and discussion section concerning the progress of

  12. Implantable Heart Aid

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Medrad utilized NASA's Apollo technology to develop a new device called the AID implantable automatic pulse generator which monitors the heart continuously, recognizes the onset of ventricular fibrillation and delivers a corrective electrical shock. AID pulse generator is, in effect, a miniaturized version of the defibrillator used by emergency squads and hospitals to restore rhythmic heartbeat after fibrillation, but has the unique advantage of being permanently available to the patient at risk. Once implanted, it needs no specially trained personnel or additional equipment. AID system consists of a microcomputer, a power source and two electrodes which sense heart activity.

  13. 21 CFR 870.5310 - Automated external defibrillator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... external defibrillator. (a) Identification. An automated external defibrillator (AED) is a low-energy... atria or ventricles of the heart. An AED analyzes the patient's electrocardiogram, interprets the cardiac rhythm, and automatically delivers an electrical shock (fully automated AED), or advises the...

  14. [Multiple inappropriate defibrillator shocks due to insulation failure of a Biotronik Linox defibrillator lead with externalized conductor].

    PubMed

    Elfarra, Hamdi; Moosdorf, Rainer; Rybinski, Leszek; Grimm, Wolfram

    2016-03-01

    In this article the case of a patient who received a total of 35 inappropriate defibrillator shocks due to insulation failure with externalized conductor of a Biotronik Linox® lead is described. The implanted defibrillator was immediately inactivated and the failed lead was extracted using a laser sheath system.

  15. Concept of defibrillation vector in the management of high defibrillation threshold

    PubMed Central

    Hayes, Kevin; Deshmukh, Abhishek; Pant, Sadip; Tobler, Gareth; Paydak, Hakan

    2013-01-01

    We present a case where defibrillation threshold was dangerously elevated to the point that the patient had no safety margin, and his implantable cardioverter-defibrillator generator was discovered to have migrated. Generator migration reduces the distance between the can and the coil, effectively creating a smaller bipolar current and sparing the left ventricle from the current needed for defibrillation. This case underscores the importance of securing the generator in place, as this patient would have been spared multiple shocks and an invasive medical procedure had his generator been better secured. PMID:23675557

  16. Increased Likelihood of Arrhythmic Events Associated with Increased Anxiety in Patients with Implanted Cardiac Defibrillators after the Ahar-Varzegan Earthquake in East Azarbaijan, 2012

    PubMed Central

    Ranjbar, Fatemeh; Akbarzadeh, Fariborz; Kazemi, Babak; Ranjbar, Abdolmohammad; Sharifi Namin, Sonia; Sadeghi-Bazargani, Homayoun

    2016-01-01

    Objective: To determine the type and pattern of arrhythmic events following the 2012 Ahar-Varzegan Earthquake among patients implanted with cardiac defibrillators (ICDs) in East Azarbaijan province. Methods: In a prospective cohort study, conducted in East Azerbaijan Province of Iran, 132 patients were enrolled in two comparison groups according to the region of residence i.e., earthquake region (n= 98) and non-earthquake (n= 34) region in 2012. Data were collected for those meeting standard criteria for sustained ventricular arrhythmias (VAs), or supraventricular tachycardias (SVTs) and triggered ICD therapies, either shock or anti-tachycardia pacing (ATP). The state version of the State-Trait Anxiety Inventory (STAI-S) was used to assess general symptoms of anxiety in both groups.  Results: Males comprised 81.1% of the participants. Mean age of the participants was 59.7 ±15 years. The frequency of patients with sustained VAs increased significantly after the earthquake (p=0.008).  There were more VAs (mean 2.16 vs. 6.23; p=0.008) and they occurred earlier (6th vs. 16th day; p= 0.01) in the earthquake area. The mean frequency of SVTs and the total number of delivered ICD therapies were similar between groups. Differences in anxiety levels were not significant between groups but there was a trend for presence of greater number of patients with anxiety (p=0.07) and the relative severity of anxiety (p=0.08) in the earthquake area. Conclusion:  In the earthquake area, the mean frequency of VAs increased and they occurred earlier in the earthquake area. The stress of anxiety might have served as a trigger for these events. PMID:27878125

  17. The Screen-ICD trial. Screening for anxiety and cognitive therapy intervention for patients with implanted cardioverter defibrillator (ICD): a randomised controlled trial protocol

    PubMed Central

    Berg, Selina Kikkenborg; Herning, Margrethe; Svendsen, Jesper Hastrup; Christensen, Anne Vinggaard; Thygesen, Lau Caspar

    2016-01-01

    Introduction Previous research shows that patients with an implanted cardioverter defibrillator (ICD) have a fourfold increased mortality risk when suffering from anxiety compared with ICD patients without anxiety. This research supports the screening of ICD patients for anxiety with the purpose of starting relevant intervention. Methods and analysis Screen-ICD consists of 3 parts: (1) screening of all hospitalised and outpatient patients at two university hospitals using the Hospital Anxiety and Depression Scale (HADS), scores ≥8 are invited to participate. (2) Assessment of type of anxiety by Structured Clinical Interview for DSM Disorders (SCID). (3) Investigator-initiated randomised clinical superiority trial with blinded outcome assessment, with 1:1 randomisation to cognitive–behavioural therapy (CBT) performed by a cardiac nurse with CBT training, plus usual care or usual care alone. The primary outcome is HADS-A measured at 16 weeks. Secondary outcomes include Becks Anxiety Inventory, HeartQoL, Hamilton Anxiety Scale, heart rate variability, ICD shock, time to first shock and antitachycardia pacing. A total of 88 participants will be included. The primary analyses are based on the intention-to-treat principle and we use a mixed model with repeated measurements for continuous outcomes. For binary outcomes (HADS-A score <8), we use a generalised mixed model with repeated measurements. Ethics and dissemination The trial is performed in accordance with the Declaration of Helsinki. All patients must give informed consent prior to participation and the trial is initiated after approval by the Danish Data Protection Agency (RH-2015-282) and the regional ethics committee (H-16018868). Positive, neutral and negative results of the trial will be published. Trial registration number NCT02713360. PMID:27798030

  18. Impact of Implantable Cardioverter-Defibrillator, Amiodarone, and Placebo on the Mode of Death in Stable Patients With Heart Failure

    PubMed Central

    Packer, Douglas L.; Prutkin, Jordan M.; Hellkamp, Anne S.; Mitchell, L. Brent; Bernstein, Robert C.; Wood, Freda; Boehmer, John P.; Carlson, Mark D.; Frantz, Robert P.; McNulty, Steve E.; Rogers, Joseph G.; Anderson, Jill; Johnson, George W.; Walsh, Mary Norine; Poole, Jeanne E.; Mark, Daniel B.; Lee, Kerry L.; Bardy, Gust H.

    2010-01-01

    Background The Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) demonstrated that implantable cardioverterdefibrillator (ICD) therapy reduces all-cause mortality in patients with New York Heart Association class II/III heart failure and a left ventricular ejection fraction ≤35% on optimal medical therapy. Whether ICD therapy reduced sudden death caused by ventricular tachyarrhythmias without affecting heart failure deaths in this population is unknown. Methods and Results SCD-HeFT randomized 2521 subjects to placebo, amiodarone, or shock-only, single-lead ICD therapy. Over a median follow-up of 45.5 months, a total of 666 deaths occurred, which were reviewed by an Events Committee and initially categorized as cardiac or noncardiac. Cardiac deaths were further adjudicated as resulting from sudden death presumed to be ventricular tachyarrhythmic, bradyarrhythmia, heart failure, or other cardiac causes. ICD therapy significantly reduced cardiac mortality compared with placebo (adjusted hazard ratio, 0.76; 95% confidence interval, 0.60 to 0.95) and tachyarrhythmia mortality (adjusted hazard ratio, 0.40; 95% confidence interval, 0.27 to 0.59) and had no impact on mortality resulting from heart failure or noncardiac causes. The cardiac and tachyarrhythmia mortality reductions were evident in subjects with New York Heart Association class II but not in subjects with class III heart failure. The reduction in tachyarrhythmia mortality with ICD therapy was similar in subjects with ischemic and nonischemic disease. Compared with placebo, amiodarone had no significant effect on any mode of death. Conclusions ICD therapy reduced cardiac mortality and sudden death presumed to be ventricular tachyarrhythmic in SCD-HeFT and had no effect on heart failure mortality. Amiodarone had no effect on all-cause mortality or its cause-specific components, except an increase in non-cardiac mortality in class III patients. PMID:19917887

  19. Estimating dose to implantable cardioverter-defibrillator outside the treatment fields using a skin QED diode, optically stimulated luminescent dosimeters, and LiF thermoluminescent dosimeters.

    PubMed

    Chan, Maria F; Song, Yulin; Dauer, Lawrence T; Li, Jingdong; Huang, David; Burman, Chandra

    2012-01-01

    The purpose of this work was to determine the relative sensitivity of skin QED diodes, optically stimulated luminescent dosimeters (OSLDs) (microStar™ DOT, Landauer), and LiF thermoluminescent dosimeters (TLDs) as a function of distance from a photon beam field edge when applied to measure dose at out-of-field points. These detectors have been used to estimate radiation dose to patients' implantable cardioverter-defibrillators (ICDs) located outside the treatment field. The ICDs have a thin outer case made of 0.4- to 0.6-mm-thick titanium (∼2.4-mm tissue equivalent). A 5-mm bolus, being the equivalent depth of the devices under the patient's skin, was placed over the ICDs. Response per unit absorbed dose-to-water was measured for each of the dosimeters with and without bolus on the beam central axis (CAX) and at a distance up to 20 cm from the CAX. Doses were measured with an ionization chamber at various depths for 6- and 15-MV x-rays on a Varian Clinac-iX linear accelerator. Relative sensitivity of the detectors was determined as the ratio of the sensitivity at each off-axis distance to that at the CAX. The detector sensitivity as a function of the distance from the field edge changed by ± 3% (1-11%) for LiF TLD-700, decreased by 10% (5-21%) for OSLD, and increased by 16% (11-19%) for the skin QED diode (Sun Nuclear Corp.) at the equivalent depth of 5 mm for 6- or 15-MV photon energies. Our results showed that the use of bolus with proper thickness (i.e., ∼d(max) of the photon energy) on the top of the ICD would reduce the scattered dose to a lower level. Dosimeters should be calibrated out-of-field and preferably with bolus equal in thickness to the depth of interest. This can be readily performed in clinic.

  20. Estimating dose to implantable cardioverter-defibrillator outside the treatment fields using a skin QED diode, optically stimulated luminescent dosimeters, and LiF thermoluminescent dosimeters

    SciTech Connect

    Chan, Maria F.; Song, Yulin; Dauer, Lawrence T.; Li Jingdong; Huang, David; Burman, Chandra

    2012-10-01

    The purpose of this work was to determine the relative sensitivity of skin QED diodes, optically stimulated luminescent dosimeters (OSLDs) (microStar Trade-Mark-Sign DOT, Landauer), and LiF thermoluminescent dosimeters (TLDs) as a function of distance from a photon beam field edge when applied to measure dose at out-of-field points. These detectors have been used to estimate radiation dose to patients' implantable cardioverter-defibrillators (ICDs) located outside the treatment field. The ICDs have a thin outer case made of 0.4- to 0.6-mm-thick titanium ({approx}2.4-mm tissue equivalent). A 5-mm bolus, being the equivalent depth of the devices under the patient's skin, was placed over the ICDs. Response per unit absorbed dose-to-water was measured for each of the dosimeters with and without bolus on the beam central axis (CAX) and at a distance up to 20 cm from the CAX. Doses were measured with an ionization chamber at various depths for 6- and 15-MV x-rays on a Varian Clinac-iX linear accelerator. Relative sensitivity of the detectors was determined as the ratio of the sensitivity at each off-axis distance to that at the CAX. The detector sensitivity as a function of the distance from the field edge changed by {+-} 3% (1-11%) for LiF TLD-700, decreased by 10% (5-21%) for OSLD, and increased by 16% (11-19%) for the skin QED diode (Sun Nuclear Corp.) at the equivalent depth of 5 mm for 6- or 15-MV photon energies. Our results showed that the use of bolus with proper thickness (i.e., {approx}d{sub max} of the photon energy) on the top of the ICD would reduce the scattered dose to a lower level. Dosimeters should be calibrated out-of-field and preferably with bolus equal in thickness to the depth of interest. This can be readily performed in clinic.

  1. Biomarker-based diagnosis of pacemaker and implantable cardioverter defibrillator pocket infections: A prospective, multicentre, case-control evaluation

    PubMed Central

    Vrazic, Hrvoje; Haller, Bernhard; Braun, Siegmund; Petzold, Tobias; Ott, Ilka; Lennerz, Agnes; Michel, Jonathan; Blažek, Patrick; Deisenhofer, Isabel; Whittaker, Peter; Kolb, Christof

    2017-01-01

    Background The use of cardiac implantable electronic devices (CIED) has risen steadily, yet the rate of cardiac device infections (CDI) has disproportionately increased. Amongst all cardiac device infections, the pocket infection is the most challenging diagnosis. Therefore, we aimed to improve diagnosis of such pocket infection by identifying relevant biomarkers. Methods We enrolled 25 consecutive patients with invasively and microbiologically confirmed pocket infection. None of the patients had any confounding conditions. Pre-operative levels of 14 biomarkers were compared in infected and control (n = 50) patients. Our selected biomarkers included white blood cell count (WBC), C-reactive protein (CRP), procalcitonin (PCT), lipopolysaccharide binding protein, high-sensitivity C-reactive protein (HS-CRP), polymorphonuclear-elastase, presepsin, various interleukins, tumor necrosis factor α (TNF-α), and granulocyte macrophage colony-stimulating factor (GM-CSF). Results Of the 25 patients with isolated pocket infection (70±13years, 76% male, 40% ICDs), none presented with leukocytosis. In contrast, they had higher serum levels of HS-CRP (p = 0.019) and PCT (p = 0.010) than control patients. Median PCT-level was 0.06 ng/mL (IQR 0.03–0.07 ng/mL) in the study group versus 0.03 ng/mL (IQR 0.02–0.04 ng/mL) in controls. An optimized PCT cut-off value of 0.05 ng/mL suggests pocket infection with a sensitivity of 60% and specificity of 82%. In addition TNF-α- and GM-CSF-levels were lower in the study group. Other biomarkers did not differ between groups. Conclusion Diagnosis of isolated pocket infections requires clinical awareness, physical examination, evaluation of blood cultures and echocardiography assessment. Nevertheless, measurement of PCT- and HS-CRP-levels can aid diagnosis. However, no conclusion can be drawn from normal WBC-values. Clinical trial registration clinicaltrials.gov identifier: NCT01619267 PMID:28264059

  2. An image analysis approach for automatically re-orienteering CT images for dental implants.

    PubMed

    Cucchiara, Rita; Lamma, Evelina; Sansoni, Tommaso

    2004-06-01

    In the last decade, computerized tomography (CT) has become the most frequently used imaging modality to obtain a correct pre-operative implant planning. In this work, we present an image analysis and computer vision approach able to identify, from the reconstructed 3D data set, the optimal cutting plane specific to each implant to be planned, in order to obtain the best view of the implant site and to have correct measures. If the patient requires more implants, different cutting planes are automatically identified, and the axial and cross-sectional images can be re-oriented accordingly to each of them. In the paper, we describe the defined algorithms in order to recognize 3D markers (each one aligned with a missed tooth for which an implant has to be planned) in the 3D reconstructed space, and the results in processing real exams, in terms of effectiveness and precision and reproducibility of the measure.

  3. Incidence of ineffective safety margin testing (<10 J) and efficacy of routine subcutaneous array insertion during implantable cardioverter defibrillator implantation.

    PubMed

    Ohlow, Marc-Alexander; Roos, Marcus; Lauer, Bernward; Geller, J Christoph

    2016-01-01

    The purpose of this study was to assess (1) the incidence of safety margin testing <10 J (SMT) and (2) the efficacy/safety of routinely adding a subcutaneous array (SQA) (Medtronic 6996SQ) for these patients. Patients with SMT smaller than a 10-J safety margin from maximum output were considered to have very high readings and underwent SQA insertion. These patients were compared with the rest of the patients who had acceptable SMT (≥10 J). A total of 616 patients underwent ICD implantation during the analysis period. Of those, 16 (2.6%) had SMT <10 J. By univariate analysis, younger age, and non-ischemic cardiomyopathy, were all significant predictors of SMT <10 J (p < 0.05). In all 16 cases, other methods to improve SMT prior to array insertion were attempted but failed for all patients: reversing shock polarity (n = 15), removing the superior vena cava coil (n = 14), reprogramming shock waveform (n = 9), and repositioning right ventricular lead (n = 9). Addition of the SQA successfully increased SMT to within safety margin for all patients (32 ± 2 versus 21 ± 3 J; p < 0.001). Follow-up (mean 48.1 ± 21 months) was available for all patients with SQA, only 2 cases with inappropriate shocks due to atrial fibrillation had to be noted. None of the patients experienced complications due to SQA implantation. SMT <10 J occur in about 2.6% of patients undergoing ICD implantation. SQA insertion corrects this problem without procedural/mid-term complications.

  4. Defibrillator-embedded rapid recovery electrocardiogram amplifier.

    PubMed

    Neycheva, T; Krasteva, V

    2003-01-01

    One of the most important performances of the defibrillator-embedded amplifier-monitor-recorder tract, connected to defibrillator electrodes, is its rapid recovery after the application of the shock pulse. Practically near-immediate restoration of the signal trace is mandatory for studies of post-shock effects on the myocardium. Automatic analysis of the electrocardiogram signal in public-access defibrillation, aiming for about 100% correct recognition of shockable and non-shockable rhythms, now requires fast amplifier settling, as the decision time should not exceed 10-20 s. Two circuits of post-shock amplifier transient suppressors were developed with non-linear feedback, resulting in second-order high-pass filtering, with gradual return to normally accepted first-order response. Simulation and testing in real conditions resulted in recovery periods in the range of 1-2 s for an amplifier tract of 1-30 Hz bandwidth, depending on the pulse waveform and electrode type.

  5. Automatic segmentation of intra-cochlear anatomy in post-implantation CT

    NASA Astrophysics Data System (ADS)

    Reda, Fitsum A.; Dawant, Benoit M.; McRackan, Theodore R.; Labadie, Robert F.; Noble, Jack H.

    2013-03-01

    A cochlear implant (CI) is a neural prosthetic device that restores hearing by directly stimulating the auditory nerve with an electrode array. In CI surgery, the surgeon threads the electrode array into the cochlea, blind to internal structures. We have recently developed algorithms for determining the position of CI electrodes relative to intra-cochlear anatomy using pre- and post-implantation CT. We are currently using this approach to develop a CI programming assistance system that uses knowledge of electrode position to determine a patient-customized CI sound processing strategy. However, this approach cannot be used for the majority of CI users because the cochlea is obscured by image artifacts produced by CI electrodes and acquisition of pre-implantation CT is not universal. In this study we propose an approach that extends our techniques so that intra-cochlear anatomy can be segmented for CI users for which pre-implantation CT was not acquired. The approach achieves automatic segmentation of intra-cochlear anatomy in post-implantation CT by exploiting intra-subject symmetry in cochlear anatomy across ears. We validated our approach on a dataset of 10 ears in which both pre- and post-implantation CTs were available. Our approach results in mean and maximum segmentation errors of 0.27 and 0.62 mm, respectively. This result suggests that our automatic segmentation approach is accurate enough for developing customized CI sound processing strategies for unilateral CI patients based solely on postimplantation CT scans.

  6. The wearable cardioverter-defibrillator: current technology and evolving indications.

    PubMed

    Reek, Sven; Burri, Haran; Roberts, Paul R; Perings, Christian; Epstein, Andrew E; Klein, Helmut U

    2016-10-04

    The wearable cardioverter-defibrillator has been available for over a decade and now is frequently prescribed for patients deemed at high arrhythmic risk in whom the underlying pathology is potentially reversible or who are awaiting an implantable cardioverter-defibrillator. The use of the wearable cardioverter-defibrillator is included in the new 2015 ESC guidelines for the management of ventricular arrhythmias and prevention of sudden cardiac death. The present review provides insight into the current technology and an overview of this approach.

  7. Automatic electrode configuration selection for image-guided cochlear implant programming

    NASA Astrophysics Data System (ADS)

    Zhao, Yiyuan; Dawant, Benoit M.; Noble, Jack H.

    2015-03-01

    Cochlear implants (CIs) are neural prosthetics that stimulate the auditory nerve pathways within the cochlea using an implanted electrode array to restore hearing. After implantation, the CI is programmed by an audiologist who determines which electrodes are active, i.e., the electrode configuration, and selects other stimulation settings. Recent clinical studies by our group have shown that hearing outcomes can be significantly improved by using an image-guided electrode configuration selection technique we have designed. Our goal in this work is to automate the electrode configuration selection step with the long term goal of developing a fully automatic system that can be translated to the clinic. Until now, the electrode configuration selection step has been performed by an expert with the assistance of image analysis-based estimates of the electrode-neural interface. To automatically determine the electrode configuration, we have designed an optimization approach and propose the use of a cost function with feature terms designed to interpret the image analysis data in a similar fashion as the expert. Further, we have designed an approach to select parameters in the cost function using our database of existing electrode configuration plans as training data. The results we present show that our automatic approach results in electrode configurations that are better or equally as good as manually selected configurations in over 80% of the cases tested. This method represents a crucial step towards clinical translation of our image-guided cochlear implant programming system.

  8. Manual for the psychotherapeutic treatment of acute and post-traumatic stress disorders following multiple shocks from implantable cardioverter defibrillator (ICD)

    PubMed Central

    Jordan, Jochen; Titscher, Georg; Peregrinova, Ludmila; Kirsch, Holger

    2013-01-01

    Background: In view of the increasing number of implanted cardioverter defibrillators (ICD), the number of people suffering from so-called “multiple ICD shocks” is also increasing. The delivery of more than five shocks (appropriate or inappropriate) in 12 months or three or more shocks (so called multiple shocks) in a short time period (24 hours) leads to an increasing number of patients suffering from severe psychological distress (anxiety disorder, panic disorder, adjustment disorder, post-traumatic stress disorder). Untreated persons show chronic disease processes and a low rate of spontaneous remission and have an increased morbidity and mortality. Few papers have been published concerning the psychotherapeutic treatment for these patients. Objective: The aim of this study is to develop a psychotherapeutic treatment for patients with a post-traumatic stress disorder or adjustment disorder after multiple ICD shocks. Design: Explorative feasibility study: Treatment of 22 patients as a natural design without randomisation and without control group. The period of recruitment was three years, from March 2007 to March 2010. The study consisted of two phases: in the first phase (pilot study) we tested different components and dosages of psychotherapeutic treatments. The final intervention programme is presented in this paper. In the second phase (follow-up study) we assessed the residual post-traumatic stress symptoms in these ICD patients. The time between treatment and follow-up measurement was 12 to 30 months. Population: Thirty-one patients were assigned to the Department of Psychocardiology after multiple shocks. The sample consisted of 22 patients who had a post-traumatic stress disorder or an adjustment disorder and were willing and able to participate. They were invited for psychological treatment. 18 of them could be included into the follow-up study. Methods: After the clinical assessment at the beginning and at the end of the inpatient treatment a post

  9. [The Wearable Cardioverter Defibrillator (WCD) for the prevention of sudden cardiac death -- a single center experience].

    PubMed

    Reek, S; Meltendorf, U; Geller, J C; Wollbrück, A; Grund, S; Klein, H U

    2002-12-01

    The Wearable Cardioverter Defibrillator (WCD) is an external defibrillator that automatically detects and treats ventricular tachyarrhythmias without the need for assistance from a bystander while at the same time allowing the patient to ambulate freely. The main components of the system are the defibrillator unit and a chest belt with electrodes for arrhythmia detection and therapy delivery. Between December 1998 and October 2001, 84 patients used the device at our institution. The majority of patients had a history of acute myocardial infarction or coronary artery bypass surgery with an increased risk for sudden cardiac death or were awaiting heart transplantation. During a mean follow-up of 116+/-90 days, 7 episodes of ventricular tachyarrhythmias were detected and terminated successfully by the WCD in 5 patients. In 9720 days, there was one inappropriate shock due to oversensing of electrical noise. Four patients died during follow-up; none of them had a cardiac arrest while wearing the device. Five patients were excluded because of irregularities in device use. An ICD was implanted in 24 patients at the end of the follow-up period. The WCD is effective in detecting and treating ventricular tachyarrhythmias in patients with an intermittently increased risk for sudden cardiac death. Further use of the system in larger patient populations is needed to confirm its safety and cost effectiveness.

  10. Long-term efficacy of implantable cardiac resynchronization therapy plus defibrillator for primary prevention of sudden cardiac death in patients with mild heart failure: an updated meta-analysis.

    PubMed

    Sun, Wei-Ping; Li, Chun-Lei; Guo, Jin-Cheng; Zhang, Li-Xin; Liu, Ran; Zhang, Hai-Bin; Zhang, Ling

    2016-07-01

    Previous studies of implantable cardiac resynchronization therapy plus defibrillator (CRT-D) therapy used for primary prevention of sudden cardiac death have suggested that CRT-D therapy is less effective in patients with mild heart failure and a wide QRS complex. However, the long-term benefits are variable. We performed a meta-analysis of randomized trials identified in systematic searches of MEDLINE, EMBASE, and the Cochrane Database. Three studies (3858 patients) with a mean follow-up of 66 months were included. Overall, CRT-D therapy was associated with significantly lower all-cause mortality than was implantable cardioverter defibrillator (ICD) therapy (OR, 0.78; 95 % CI, 0.63-0.96; P = 0.02; I (2) = 19 %). However, the risk of cardiac mortality was comparable between two groups (OR, 0.74; 95 % CI, 0.53-1.01; P = 0.06). CRT-D treatment was associated with a significantly lower risk of hospitalization for heart failure (OR, 0.67; 95 % CI, 0.50-0.89; P = 0.005; I (2) = 55 %). The composite outcome of all-cause mortality and hospitalization for heart failure was also markedly lower with CRT-D therapy than with ICD treatment alone (OR, 0.67; 95 % CI, 0.57-0.77; P < 0.0001; I (2) = 0 %). CRT-D therapy decreased the long-term risk of mortality and heart failure events in patients with mild heart failure with a wide QRS complex. However, long-term risk of cardiac mortality was similar between two groups. More randomized studies are needed to confirm these findings, especially in patients with NYHA class I heart failure or patients without LBBB.

  11. Initial dynamics of the EKG during an electrical defibrillation of the heart

    NASA Technical Reports Server (NTRS)

    Bikov, I. I.; Chebotarov, Y. P.; Nikolaev, V. G.

    1980-01-01

    In tests on 11 mature dogs, immobilized by means of an automatic blocking and synchronization system, artefact free EKG were obtained, beginning 0.04-0.06 sec after passage of a defibrillating current. Different versions of the start of fibrillation were noted, in application of the defibrillating stimulus in the early phase of the cardiac cycle. A swinging phenomenon, increasing amplitude, of fibrillation was noted for 0.4-1.5 sec after delivery of a subthreshold stimulus. Conditions for a positive outcome of repeated defibrillation were found, and a relationship was noted between the configuration of the exciting process with respect to the lines of force of the defibrillating current and the defibrillation threshold. It was shown that the initial EKG dynamics after defibrillation is based on a gradual shift of the pacemaker from the myocardium of the ventricles to the sinus node, through phases of atrioventricular and atrial automatism.

  12. Mechanisms of Defibrillation

    PubMed Central

    Dosdall, Derek J.; Fast, Vladimir G.; Ideker, Raymond E.

    2014-01-01

    Electrical shock has been the one effective treatment for ventricular fibrillation for several decades. With the advancement of electrical and optical mapping techniques, histology, and computer modeling, the mechanisms responsible for defibrillation are now coming to light. In this review, we discuss recent work that demonstrates the various mechanisms responsible for defibrillation. On the cellular level, membrane depolarization and electroporation affect defibrillation outcome. Cell bundles and collagenous septae are secondary sources and cause virtual electrodes at sites far from shocking electrodes. On the whole-heart level, shock field gradient and critical points determine whether a shock is successful or whether reentry causes initiation and continuation of fibrillation. PMID:20450352

  13. Ventricular fibrillation and defibrillation

    PubMed Central

    Jones, P; Lodé, N

    2007-01-01

    Cardiac arrest in children is not often due to a disturbance in rhythm that is amenable to electrical defibrillation, contrary to the situation in adults. When a shockable rhythm is present, defibrillation using an external electric shock applied at an early stage after pre‐oxygenation and chest compressions is of proven efficacy. Success at conversion of ventricular fibrillation is dependent on the delay before delivering the shock and defibrillation efficiency, which is itself a function of thoracic impedance, energy dose and waveform. PMID:17895341

  14. [Magnets, pacemaker and defibrillator: fatal attraction?].

    PubMed

    Bergamin, C; Graf, D

    2015-05-27

    This article aims at clarifying the effects of a clinical magnet on pacemakers and Implantable Cardioverter Defibrillators. The effects of electromagnetic interferences on such devices, including interferences linked to electrosurgery and magnetic resonance imaging are also discussed. In general, a magnet provokes a distinctive effect on a pacemaker by converting it into an asynchronous mode of pacing, and on an Implantable Cardioverter Defibrillator by suspending its own antitachyarythmia therapies without affecting the pacing. In the operating room, the magnet has to be used cautiously with precisely defined protocols which respect the type of the device used, the type of intervention planned, the presence or absence of EMI and the pacing-dependency of the patient.

  15. Towards Low Energy Atrial Defibrillation.

    PubMed

    Walsh, Philip; Kodoth, Vivek; McEneaney, David; Rodrigues, Paola; Velasquez, Jose; Waterman, Niall; Escalona, Omar

    2015-09-03

    A wireless powered implantable atrial defibrillator consisting of a battery driven hand-held radio frequency (RF) power transmitter (ex vivo) and a passive (battery free) implantable power receiver (in vivo) that enables measurement of the intracardiac impedance (ICI) during internal atrial defibrillation is reported. The architecture is designed to operate in two modes: Cardiac sense mode (power-up, measure the impedance of the cardiac substrate and communicate data to the ex vivo power transmitter) and cardiac shock mode (delivery of a synchronised very low tilt rectilinear electrical shock waveform). An initial prototype was implemented and tested. In low-power (sense) mode, >5 W was delivered across a 2.5 cm air-skin gap to facilitate measurement of the impedance of the cardiac substrate. In high-power (shock) mode, >180 W (delivered as a 12 ms monophasic very-low-tilt-rectilinear (M-VLTR) or as a 12 ms biphasic very-low-tilt-rectilinear (B-VLTR) chronosymmetric (6ms/6ms) amplitude asymmetric (negative phase at 50% magnitude) shock was reliably and repeatedly delivered across the same interface; with >47% DC-to-DC (direct current to direct current) power transfer efficiency at a switching frequency of 185 kHz achieved. In an initial trial of the RF architecture developed, 30 patients with AF were randomised to therapy with an RF generated M-VLTR or B-VLTR shock using a step-up voltage protocol (50-300 V). Mean energy for successful cardioversion was 8.51 J ± 3.16 J. Subsequent analysis revealed that all patients who cardioverted exhibited a significant decrease in ICI between the first and third shocks (5.00 Ω (SD(σ) = 1.62 Ω), p < 0.01) while spectral analysis across frequency also revealed a significant variation in the impedance-amplitude-spectrum-area (IAMSA) within the same patient group (|∆(IAMSAS1-IAMSAS3)[1 Hz - 20 kHz] = 20.82 Ω-Hz (SD(σ) = 10.77 Ω-Hz), p < 0.01); both trends being absent in all patients that failed to cardiovert. Efficient

  16. Towards Low Energy Atrial Defibrillation

    PubMed Central

    Walsh, Philip; Kodoth, Vivek; McEneaney, David; Rodrigues, Paola; Velasquez, Jose; Waterman, Niall; Escalona, Omar

    2015-01-01

    A wireless powered implantable atrial defibrillator consisting of a battery driven hand-held radio frequency (RF) power transmitter (ex vivo) and a passive (battery free) implantable power receiver (in vivo) that enables measurement of the intracardiacimpedance (ICI) during internal atrial defibrillation is reported. The architecture is designed to operate in two modes: Cardiac sense mode (power-up, measure the impedance of the cardiac substrate and communicate data to the ex vivo power transmitter) and cardiac shock mode (delivery of a synchronised very low tilt rectilinear electrical shock waveform). An initial prototype was implemented and tested. In low-power (sense) mode, >5 W was delivered across a 2.5 cm air-skin gap to facilitate measurement of the impedance of the cardiac substrate. In high-power (shock) mode, >180 W (delivered as a 12 ms monophasic very-low-tilt-rectilinear (M-VLTR) or as a 12 ms biphasic very-low-tilt-rectilinear (B-VLTR) chronosymmetric (6ms/6ms) amplitude asymmetric (negative phase at 50% magnitude) shock was reliably and repeatedly delivered across the same interface; with >47% DC-to-DC (direct current to direct current) power transfer efficiency at a switching frequency of 185 kHz achieved. In an initial trial of the RF architecture developed, 30 patients with AF were randomised to therapy with an RF generated M-VLTR or B-VLTR shock using a step-up voltage protocol (50–300 V). Mean energy for successful cardioversion was 8.51 J ± 3.16 J. Subsequent analysis revealed that all patients who cardioverted exhibited a significant decrease in ICI between the first and third shocks (5.00 Ω (SD(σ) = 1.62 Ω), p < 0.01) while spectral analysis across frequency also revealed a significant variation in the impedance-amplitude-spectrum-area (IAMSA) within the same patient group (|∆(IAMSAS1-IAMSAS3)[1 Hz − 20 kHz] = 20.82 Ω-Hz (SD(σ) = 10.77 Ω-Hz), p < 0.01); both trends being absent in all patients that failed to cardiovert. Efficient

  17. Low Energy Defibrillation in Human Cardiac Tissue: A Simulation Study

    PubMed Central

    Morgan, Stuart W.; Plank, Gernot; Biktasheva, Irina V.; Biktashev, Vadim N.

    2009-01-01

    We aim to assess the effectiveness of feedback-controlled resonant drift pacing as a method for low energy defibrillation. Antitachycardia pacing is the only low energy defibrillation approach to have gained clinical significance, but it is still suboptimal. Low energy defibrillation would avoid adverse side effects associated with high voltage shocks and allow the application of implantable cardioverter defibrillator (ICD) therapy, in cases where such therapy is not tolerated today. We present results of computer simulations of a bidomain model of cardiac tissue with human atrial ionic kinetics. Reentry was initiated and low energy shocks were applied with the same period as the reentry, using feedback to maintain resonance. We demonstrate that such stimulation can move the core of reentrant patterns, in the direction that depends on the location of the electrodes and the time delay in the feedback. Termination of reentry is achieved with shock strength one-order-of-magnitude weaker than in conventional single-shock defibrillation. We conclude that resonant drift pacing can terminate reentry at a fraction of the shock strength currently used for defibrillation and can potentially work where antitachycardia pacing fails, due to the feedback mechanisms. Success depends on a number of details that these numerical simulations have uncovered. PMID:19217854

  18. Use of a wearable defibrillator in terminating tachyarrhythmias in patients at high risk for sudden death: results of the WEARIT/BIROAD.

    PubMed

    Feldman, Arthur M; Klein, Helmut; Tchou, Patrick; Murali, Srinivas; Hall, W Jackson; Mancini, Donna; Boehmer, John; Harvey, Mark; Heilman, M Stephen; Szymkiewicz, Steven J; Moss, Arthur J

    2004-01-01

    The automatic ICD improves survival in patients with a history of sudden cardiac arrest. However, some patients do not meet the guidelines for ICD implantation or are unable to receive an implantable device. This study tested the hypothesis that these patients could benefit from a wearable cardioverter defibrillator. Patients with symptomatic heart failure and an ejection fraction of <0.30 (WEARIT Study) or patients having complications associated with high risk for sudden death after a myocardial infarction or bypass surgery not receiving an ICD for up to 4 months (BIROAD Study) were enrolled into two studies. After a total of 289 patients had been enrolled in the trial (177 in WEARIT and 112 in BIROAD), prespecified safety and effectiveness guidelines had been met. Six (75%) of eight defibrillation attempts were successful. Six inappropriate shock episodes occurred during 901 months of patient use (0.67% unnecessary shocks per month of use). Twelve deaths occurred during the study 6 sudden deaths: 5 not wearing and 1 incorrectly wearing the device). Most patients tolerated the device although 68 patients quit due to comfort issues or adverse reactions. The results of the present study suggest that a wearable defibrillator is beneficial in detecting and effectively treating ventricular tachyarrhythmias in patients at high risk for sudden death who are not clear candidates for an ICD and may be useful as a bridge to transplantation or ICD in some patients.

  19. Automatic tracking of arbitrarily shaped implanted markers in kilovoltage projection images: A feasibility study

    SciTech Connect

    Regmi, Rajesh; Lovelock, D. Michael; Hunt, Margie; Zhang, Pengpeng; Pham, Hai; Xiong, Jianping; Yorke, Ellen D.; Mageras, Gig S.; Goodman, Karyn A.; Rimner, Andreas; Mostafavi, Hassan

    2014-07-15

    Purpose: Certain types of commonly used fiducial markers take on irregular shapes upon implantation in soft tissue. This poses a challenge for methods that assume a predefined shape of markers when automatically tracking such markers in kilovoltage (kV) radiographs. The authors have developed a method of automatically tracking regularly and irregularly shaped markers using kV projection images and assessed its potential for detecting intrafractional target motion during rotational treatment. Methods: Template-based matching used a normalized cross-correlation with simplex minimization. Templates were created from computed tomography (CT) images for phantom studies and from end-expiration breath-hold planning CT for patient studies. The kV images were processed using a Sobel filter to enhance marker visibility. To correct for changes in intermarker relative positions between simulation and treatment that can introduce errors in automatic matching, marker offsets in three dimensions were manually determined from an approximately orthogonal pair of kV images. Two studies in anthropomorphic phantom were carried out, one using a gold cylindrical marker representing regular shape, another using a Visicoil marker representing irregular shape. Automatic matching of templates to cone beam CT (CBCT) projection images was performed to known marker positions in phantom. In patient data, automatic matching was compared to manual matching as an approximate ground truth. Positional discrepancy between automatic and manual matching of less than 2 mm was assumed as the criterion for successful tracking. Tracking success rates were examined in kV projection images from 22 CBCT scans of four pancreas, six gastroesophageal junction, and one lung cancer patients. Each patient had at least one irregularly shaped radiopaque marker implanted in or near the tumor. In addition, automatic tracking was tested in intrafraction kV images of three lung cancer patients with irregularly shaped

  20. Automatic tracking of arbitrarily shaped implanted markers in kilovoltage projection images: A feasibility study

    PubMed Central

    Regmi, Rajesh; Lovelock, D. Michael; Hunt, Margie; Zhang, Pengpeng; Pham, Hai; Xiong, Jianping; Yorke, Ellen D.; Goodman, Karyn A.; Rimner, Andreas; Mostafavi, Hassan; Mageras, Gig S.

    2014-01-01

    Purpose: Certain types of commonly used fiducial markers take on irregular shapes upon implantation in soft tissue. This poses a challenge for methods that assume a predefined shape of markers when automatically tracking such markers in kilovoltage (kV) radiographs. The authors have developed a method of automatically tracking regularly and irregularly shaped markers using kV projection images and assessed its potential for detecting intrafractional target motion during rotational treatment. Methods: Template-based matching used a normalized cross-correlation with simplex minimization. Templates were created from computed tomography (CT) images for phantom studies and from end-expiration breath-hold planning CT for patient studies. The kV images were processed using a Sobel filter to enhance marker visibility. To correct for changes in intermarker relative positions between simulation and treatment that can introduce errors in automatic matching, marker offsets in three dimensions were manually determined from an approximately orthogonal pair of kV images. Two studies in anthropomorphic phantom were carried out, one using a gold cylindrical marker representing regular shape, another using a Visicoil marker representing irregular shape. Automatic matching of templates to cone beam CT (CBCT) projection images was performed to known marker positions in phantom. In patient data, automatic matching was compared to manual matching as an approximate ground truth. Positional discrepancy between automatic and manual matching of less than 2 mm was assumed as the criterion for successful tracking. Tracking success rates were examined in kV projection images from 22 CBCT scans of four pancreas, six gastroesophageal junction, and one lung cancer patients. Each patient had at least one irregularly shaped radiopaque marker implanted in or near the tumor. In addition, automatic tracking was tested in intrafraction kV images of three lung cancer patients with irregularly shaped

  1. Determinants of all-cause mortality in different age groups in patients with severe systolic left ventricular dysfunction receiving an implantable cardioverter defibrillator (from the Italian ClinicalService Multicenter Observational Project).

    PubMed

    Fumagalli, Stefano; Gasparini, Maurizio; Landolina, Maurizio; Lunati, Maurizio; Boriani, Giuseppe; Proclemer, Alessandro; Santini, Massimo; Mangoni, Lorenza; Padeletti, Margherita; Marchionni, Niccolò; Padeletti, Luigi

    2014-05-15

    Heart failure (HF) is a common condition in elderly patients. Despite great improvements in medical therapy, HF mortality remains high. Implantable cardioverter defibrillator (ICD) significantly lengthens the survival rate of subjects with severe HF, but little evidence exists on its effect in elderly persons. Aim of this study was to compare the age-related determinants of prognosis in a large population of patients with ICD. We divided all patients who underwent an ICD implantation in 117 Italian centers of the "ClinicalService Project" into 3 age groups (<65, 65 to 74, ≥ 75 years), and collected clinical and instrumental variables at baseline and during follow-up (median length: 27 months). Between 2004 and 2011, 6,311 patients were enrolled (5,174 men; left ventricular ejection fraction 29% ± 9%); 1,510 subjects were ≥ 75 years (23.9%; mean age 78 ± 3 years). The prevalence of co-morbidities increased with age. HF was most frequently due to coronary artery disease in the elderly, who also showed the worst New York Heart Association class. At multivariate analysis, older age, coronary artery disease, chronic obstructive pulmonary disease, chronic renal failure, diabetes, complex ventricular arrhythmias, and left ventricular ejection fraction were significant predictors of all-cause mortality. After adjustment, the hazard ratio(age group) for mortality was 22.6% less than at univariate analysis. When groups were analyzed separately, age alone predicted mortality in the oldest. In conclusion, a large proportion of our population was aged ≥ 75 years. Mortality was related to age and several co-morbidities, except for the oldest patients in whom age alone resulted predictive.

  2. 21 CFR 870.5310 - Automated external defibrillator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... shock of a maximum of 360 joules of energy used for defibrillating (restoring normal heart rhythm) the... cardiac rhythm, and automatically delivers an electrical shock (fully automated AED), or advises the user to deliver the shock (semi-automated or shock advisory AED) to treat ventricular fibrillation...

  3. Automatic mode switching of implantable pacemakers: I. Principles of instrumentation, clinical, and hemodynamic considerations.

    PubMed

    Lau, Chu-Pak; Leung, Sum-Kin; Tse, Hung-Fat; Barold, S Serge

    2002-06-01

    Automatic mode switching (AMS) is now a programmable function in most contemporary dual chamber pacemakers. Atrial tachyarrhythmias are detected when the sensed atrial rate exceeds a "rate-cutoff," "running average," "sensor-based physiological" rate, or using "complex" detection algorithms. AMS algorithms differ in their atrial tachyarrhythmia detection method, sensitivity, and specificity and, thus, respond differently to atrial tachyarrhythmia in terms of speed to the AMS onset, rate stability of the response, and speed to resynchronize to sinus rhythm. AMS is hemodynamically beneficial, and most patients with atrial tachyarrhythmias are symptomatically better with an AMS algorithm in their pacemakers. New diagnostic capabilities of pacemaker especially stored electrograms not only allow programming of the AMS function, but enable quantification of atrial fibrillation burden that facilitate clinical management of patients with implantable devices who have concomitant atrial tachyarrhythmia.

  4. Methods for testing automatic mode switching in patients implanted with DDD(R) pacemakers.

    PubMed

    Lau, Chu-Pak; Mascia, Franco; Corbucci, Giorgio; Padeletti, Luigi

    2004-01-01

    The assessment of automatic mode switching (AMS) algorithms is impossible in vivo, due to a low chance of seeing the patient at the onset of a spontaneous episode of atrial fibrillation (AF). As the induction of AF to test AMS has clinical concerns, three alternative and non-invasive techniques may be proposed for this purpose: myopotentials, chest wall stimulation, and an external supraventricular arrhythmia simulator. The first method is simple and does not require additional equipment, even though in some patients adequate signals cannot be generated with a soft effort such as handgrip or hand compression. The main advantage of the chest wall stimulation method is the possibility that it be performed in every implanting center, since it is based on the use of standard devices for cardiac stimulation. The method based on the external supraventricular arrhythmia simulator allows the most detailed of the ECG traces, but it needs a dedicated electronic device.

  5. Defibrillator/monitor/pacemakers.

    PubMed

    1998-02-01

    This study updates our May-June 1993 Evaluation of defibrillator/monitor/pacemakers, published in Health Devices 22(5-6), in which we tested eight units from six suppliers. For this Update Evaluation, we tested three additional units, each from a different supplier. We also present update information, including some new ratings, for most of the previously evaluated units. We judged the new units against the same basic criteria and rated and ranked them using the same scheme--with some minor revisions--as in our original Evaluation. We judged the suitability of these units for three primary clinical applications: (1) general crash-cart use, (2) prehospital (emergency medical service [EMS]) use, and (3) in-hospital transport use. Because our criteria have changed slightly since the original study, we have repeated them in this issue. The test methods have not changed significantly and can be found in the original 1993 Evaluation. For more detailed information about this technology, the environments in which these units are used, and the factors to consider when selecting this type of device, we encourage readers to refer to the following sections in the original Evaluation: the Clinical Perspective "The Importance of Early Defibrillation"; the Clinical and Technical Overview; and the Selection and Use Guide for Defibrillator/Monitor/Pacemakers.

  6. Automatic selection of the active electrode set for image-guided cochlear implant programming.

    PubMed

    Zhao, Yiyuan; Dawant, Benoit M; Noble, Jack H

    2016-07-01

    Cochlear implants (CIs) are neural prostheses that restore hearing by stimulating auditory nerve pathways within the cochlea using an implanted electrode array. Research has shown when multiple electrodes stimulate the same nerve pathways, competing stimulation occurs and hearing outcomes decline. Recent clinical studies have indicated that hearing outcomes can be significantly improved by using an image-guided active electrode set selection technique we have designed, in which electrodes that cause competing stimulation are identified and deactivated. In tests done to date, an expert is needed to perform the electrode selection step with the assistance of a method to visualize the spatial relationship between electrodes and neural sites determined using image analysis techniques. We propose to automate the electrode selection step by optimizing a cost function that captures the heuristics used by the expert. Further, we propose an approach to estimate the values of parameters used in the cost function using an existing database of expert electrode selections. We test this method with different electrode array models from three manufacturers. Our automatic approach generates acceptable active electrode sets in 98.3% of the subjects tested. This approach represents a crucial step toward clinical translation of our image-guided CI programming system.

  7. The Effect of Automatic Gain Control Structure and Release Time on Cochlear Implant Speech Intelligibility

    PubMed Central

    Khing, Phyu P.; Swanson, Brett A.; Ambikairajah, Eliathamby

    2013-01-01

    Nucleus cochlear implant systems incorporate a fast-acting front-end automatic gain control (AGC), sometimes called a compression limiter. The objective of the present study was to determine the effect of replacing the front-end compression limiter with a newly proposed envelope profile limiter. A secondary objective was to investigate the effect of AGC speed on cochlear implant speech intelligibility. The envelope profile limiter was located after the filter bank and reduced the gain when the largest of the filter bank envelopes exceeded the compression threshold. The compression threshold was set equal to the saturation level of the loudness growth function (i.e. the envelope level that mapped to the maximum comfortable current level), ensuring that no envelope clipping occurred. To preserve the spectral profile, the same gain was applied to all channels. Experiment 1 compared sentence recognition with the front-end limiter and with the envelope profile limiter, each with two release times (75 and 625 ms). Six implant recipients were tested in quiet and in four-talker babble noise, at a high presentation level of 89 dB SPL. Overall, release time had a larger effect than the AGC type. With both AGC types, speech intelligibility was lower for the 75 ms release time than for the 625 ms release time. With the shorter release time, the envelope profile limiter provided higher group mean scores than the front-end limiter in quiet, but there was no significant difference in noise. Experiment 2 measured sentence recognition in noise as a function of presentation level, from 55 to 89 dB SPL. The envelope profile limiter with 625 ms release time yielded better scores than the front-end limiter with 75 ms release time. A take-home study showed no clear pattern of preferences. It is concluded that the envelope profile limiter is a feasible alternative to a front-end compression limiter. PMID:24312408

  8. Polymorphisms associated with ventricular tachyarrhythmias: rationale, design, and endpoints of the 'diagnostic data influence on disease management and relation of genomics to ventricular tachyarrhythmias in implantable cardioverter/defibrillator patients (DISCOVERY)' study.

    PubMed

    Wieneke, Heinrich; Spencker, Sebastian; Svendsen, Jesper Hastrup; Martinez, Juan Gabriel; Strohmer, Bernhard; Toivonen, Lauri; Le Marec, Hervé; Garcia, Javier; Kaup, Bernd; Soykan, Orhan; Corrado, Domenico; Siffert, Winfried

    2010-03-01

    Implantable cardioverter-defibrillator (ICD) therapy is effective in primary and secondary prevention for patients who are at high risk of sudden cardiac death. However, the current risk stratification of patients who may benefit from this therapy is unsatisfactory. Single nucleotide polymorphisms (SNPs) are DNA sequence variations occurring when a single nucleotide in the genome differs among members of a species. A novel concept has emerged being that these common genetic variations might modify the susceptibility of a certain population to specific diseases. Thus, genetic factors may also modulate the risk for arrhythmias and sudden cardiac death, and identification of common variants could help to better identify patients at risk. The DISCOVERY study is an interventional, longitudinal, prospective, multi-centre diagnostic study that will enrol 1287 patients in approximately 80 European centres. In the genetic part of the DISCOVERY study, candidate gene polymorphisms involved in coding of the G-protein subunits will be correlated with the occurrence of ventricular arrhythmias in patients receiving an ICD for primary prevention. Furthermore, in order to search for additional sequence variants contributing to ventricular arrhythmias, a genome-wide association study will be conducted if sufficient a priori evidence can be gathered. In the second part of the study, associations of SNPs with ventricular arrhythmias will be sought and a search for potential new biological arrhythmic pathways will be investigated. As it is a diagnostic study, DISCOVERY will also investigate the impact of long-term device diagnostic data on the management of patients suffering from chronic cardiac disease as well as medical decisions made regarding their treatment.

  9. The CopenHeartSF trial—comprehensive sexual rehabilitation programme for male patients with implantable cardioverter defibrillator or ischaemic heart disease and impaired sexual function: protocol of a randomised clinical trial

    PubMed Central

    Johansen, Pernille Palm; Zwisler, Ann-Dorthe; Hastrup-Svendsen, Jesper; Frederiksen, Marianne; Lindschou, Jane; Winkel, Per; Gluud, Christian; Giraldi, Annamaria; Steinke, Elaine; Jaarsma, Tiny; Berg, Selina Kikkenborg

    2013-01-01

    Introduction Sexuality is an important part of people’s physical and mental health. Patients with heart disease often suffer from sexual dysfunction. Sexual dysfunction has a negative impact on quality of life and well-being in persons with heart disease, and sexual dysfunction is associated with anxiety and depression. Treatment and care possibilities seem to be lacking. Studies indicate that non-pharmacological interventions such as exercise training and psychoeducation possess the potential of reducing sexual dysfunction in patients with heart disease. The CopenHeartSF trial will investigate the effect of a comprehensive sexual rehabilitation programme versus usual care. Methods and analysis CopenHeartSF is an investigator-initiated randomised clinical superiority trial with blinded outcome assessment, with 1:1 central randomisation to sexual rehabilitation plus usual care versus usual care alone. Based on sample size calculations, 154 male patients with impaired sexual function due to implantable cardioverter defibrillator or ischaemic heart disease will be included from two university hospitals in Denmark. All patients receive usual care and patients allocated to the experimental intervention group follow a 12-week sexual rehabilitation programme consisting of an individualised exercise programme and psychoeducative consultation with a specially trained nurse. The primary outcome is sexual function measured by the International Index of Erectile Function. The secondary outcome measure is psychosocial adjustment to illness by the Psychosocial Adjustment to Illness Scale, sexual domain. A number of explorative analyses will also be conducted. Ethics and dissemination CopenHeartSF is approved by the regional ethics committee (no H-4-2012-168) and the Danish Data Protection Agency (no 2007-58-0015) and is performed in accordance with good clinical practice and the Declaration of Helsinki in its latest form. Registration Clinicaltrials.gov identifier: NCT01796353

  10. New concepts in transthoracic defibrillation.

    PubMed

    White, Roger D

    2002-11-01

    The transition of biphasic waveforms from ICDs to external defibrillators constitutes a significant technological advances for transthoracic defibrillation. Impedance compensation has enabled the delivery of defibrillating current adapted to each patient and each shock in the same patient. Optimally designed biphasic waveforms have been shown clinically to have greater efficacy in the termination of VF when compared with monophasic waveforms, and because peak current delivery is less, these waveforms are likely to be less injurious to myocardial function. Advances in the understanding of the mechanisms of fibrillation and defibrillation have identified the electrophysiologic events that initiate and sustain VF and the effects of defibrillation shocks on those events. Definition of the role of VEP and postshock excitation has clarified the mechanisms by which shocks can either fail or succeed. The ability of the second phase of optimal biphasic waveform shocks to exploit recruited sodium channels in negatively polarized areas and thus induce rapid propagation of postshock excitation assures uniform depolarization and prevention of re-entry. This appears to be the major mechanism of greater efficacy of biphasic waveforms. It seems certain that continuing investigation of virtual electrodes will enhance our understanding of defibrillation and optimal waveforms. At the same time, much more needs to be known regarding translation of these experimental observations to mechanisms of defibrillation in human hearts with long-standing underlying structural heart disease, which often arises of multiple factors. This represents a major challenge in defibrillation research.

  11. Myopotentials leading to ventricular fibrillation detection after advisory defibrillator generator replacement.

    PubMed

    Eckart, Robert E; Hruczkowski, Tomasz W; Stevenson, William G; Epstein, Laurence M

    2006-11-01

    We present an unusual source of oversensing following an internal cardioverter-defibrillator generator change. The early appearance of reproducible myopotentials in the defibrillator sensing channel is usually due to a technical complication at the time of device implantation. Clues such as abrupt impedance change or reproduction with mechanical stimulation can help to localize a problem. Frequently the complication requires reoperation to examine the system. What do you do when everything seems to be working fine?

  12. Semi-automatic attenuation of cochlear implant artifacts for the evaluation of late auditory evoked potentials.

    PubMed

    Viola, Filipa Campos; De Vos, Maarten; Hine, Jemma; Sandmann, Pascale; Bleeck, Stefan; Eyles, Julie; Debener, Stefan

    2012-02-01

    Electrical artifacts caused by the cochlear implant (CI) contaminate electroencephalographic (EEG) recordings from implanted individuals and corrupt auditory evoked potentials (AEPs). Independent component analysis (ICA) is efficient in attenuating the electrical CI artifact and AEPs can be successfully reconstructed. However the manual selection of CI artifact related independent components (ICs) obtained with ICA is unsatisfactory, since it contains expert-choices and is time consuming. We developed a new procedure to evaluate temporal and topographical properties of ICs and semi-automatically select those components representing electrical CI artifact. The CI Artifact Correction (CIAC) algorithm was tested on EEG data from two different studies. The first consists of published datasets from 18 CI users listening to environmental sounds. Compared to the manual IC selection performed by an expert the sensitivity of CIAC was 91.7% and the specificity 92.3%. After CIAC-based attenuation of CI artifacts, a high correlation between age and N1-P2 peak-to-peak amplitude was observed in the AEPs, replicating previously reported findings and further confirming the algorithm's validity. In the second study AEPs in response to pure tone and white noise stimuli from 12 CI users that had also participated in the other study were evaluated. CI artifacts were attenuated based on the IC selection performed semi-automatically by CIAC and manually by one expert. Again, a correlation between N1 amplitude and age was found. Moreover, a high test-retest reliability for AEP N1 amplitudes and latencies suggested that CIAC-based attenuation reliably preserves plausible individual response characteristics. We conclude that CIAC enables the objective and efficient attenuation of the CI artifact in EEG recordings, as it provided a reasonable reconstruction of individual AEPs. The systematic pattern of individual differences in N1 amplitudes and latencies observed with different stimuli at

  13. Clinical management of electromagnetic interferences in patients with pacemakers and implantable cardioverter-defibrillators: review of the literature and focus on magnetic resonance conditional devices.

    PubMed

    Corzani, Alessandro; Ziacchi, Matteo; Biffi, Mauro; Allaria, Luca; Diemberger, Igor; Martignani, Cristian; Bratten, Tara; Gardini, Beatrice; Boriani, Giuseppe

    2015-10-01

    The number of cardiac implantable electronic devices (CIEDs) has greatly increased in the last 10 years. Many electronic devices used in daily activities generate electromagnetic interferences (EMIs) that can interact with CIEDs. In clinical practice, it is very important to know the potential sources of EMIs and their effect on CIEDs in order to understand how to manage or mitigate them. A very important source of EMI is magnetic resonance (MR), which is considered nowadays the diagnostic gold standard for different anatomical districts. In this review, we focused on the effects of EMI on CIEDs and on the clinical management. Moreover, we made a clarification about MR and CIEDs.In patients with CIEDs, EMIs may cause potentially serious and even life-threatening complications (inappropriate shocks, device malfunctions, inhibition of pacing in pacemaker-dependent patients) and may rarely dictate device replacement. The association of inappropriate shocks with increased mortality highlights the importance of minimizing the occurrence of EMI. Adequate advice and recommendations about the correct management of EMIs in patients with CIEDs are required to avoid all complications during hospitalization and in daily life. Furthermore, the article focused on actual management about MR and CIEDs.

  14. A cellular transtelephonic defibrillator for management of cardiac arrest outside the hospital.

    PubMed

    Dalzell, G W; McKeown, P P; Roberts, M J; Adgey, A A

    1991-10-01

    A cellular transtelephonic defibrillator facilitates early defibrillation in remote areas and involves electrocardiographic diagnosis and defibrillation control by a physician remote from but in voice contact with the patient-unit operator. The patient unit contains a microprocessor, microphone, defibrillator, electrocardiogram/defibrillator electrode pads and cellular telephone. Activation of the patient-unit initiates automatic dialing and contact with the remotely sited base station within 35 to 50 seconds. The physician at the base station identifies the rhythm and controls defibrillator charging and discharge. The minimal interaction required between the system and the local operator makes it suitable for use by minimally trained first responders. The cellular transtelephonic defibrillator has been tested in 211 calls responded to by a physician-manned mobile coronary care unit over distances up to 15 miles in an urban area. Satisfactory electrocardiographic transmission and voice communication were established in 172 of 211 calls (81.5%). In 39 (18.5%), connection with the base station either could not be established or maintained mainly because of geographic location or battery failure. One hundred direct current shocks of 50 to 360 J were effectively administered to 22 patients with 48 episodes of ventricular fibrillation or ventricular tachycardia with successful correction of 46 of 48 episodes using 1 to 4 shocks per episode. Widespread distribution of such devices could improve survival in patients with cardiac arrest outside the hospital.

  15. AMBIENT AIR POLLUTION AND ARRHYTHMIC EVENTS IN PATIENTS WITH AUTOMATIC IMPLANTABLE CARDIOVERTER DEFIBRILLATORS, ATLANTA, 1993-2000 (ARIES/SOPHIA). (R829213)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  16. Inadvertent transposition of defibrillator coil terminal pins causing inappropriate ICD therapies.

    PubMed

    Issa, Ziad F

    2008-06-01

    We report the case of a 65-year-old man with chronic atrial fibrillation (AF) and severe ischemic cardiomyopathy who underwent implantation of a prophylactic single-chamber implantable cardioverter-defibrillator (ICD). The patient experienced inappropriate ICD therapies due to oversensing of pectoral muscle myopotential secondary to reversal of the defibrillator coil terminal pins in the ICD header. Recognizing this possibility is important to avoid misinterpretation of spontaneous oversensing as hardware failure (e.g., lead fracture or insulation breech) and potentially unnecessary ICD system surgical intervention, including lead extraction.

  17. Who Needs an Implantable Cardioverter Defibrillator?

    MedlinePlus

    ... Electrophysiology Study For this test, a thin, flexible wire is passed through a vein in your groin (upper thigh) or arm to your heart. The wire records the heart's electrical signals. Your doctor uses ...

  18. Elderly Benefit from Using Implantable Defibrillators

    MedlinePlus

    ... function due to a prior heart attack or heart failure , or after being resuscitated from cardiac arrest . “Older patients were just as likely to experience an appropriate electrical shock from the device to treat a life-threatening ...

  19. Living with Your Implantable Cardioverter Defibrillator (ICD)

    MedlinePlus

    ... the phone or through an Internet connection. ICD batteries last 5 to 7 years. Your doctor uses a special analyzer to detect the first warning that the batteries are running down, before you can detect any ...

  20. Implantable Microimagers

    PubMed Central

    Ng, David C.; Tokuda, Takashi; Shiosaka, Sadao; Tano, Yasuo; Ohta, Jun

    2008-01-01

    Implantable devices such as cardiac pacemakers, drug-delivery systems, and defibrillators have had a tremendous impact on the quality of live for many disabled people. To date, many devices have been developed for implantation into various parts of the human body. In this paper, we focus on devices implanted in the head. In particular, we describe the technologies necessary to create implantable microimagers. Design, fabrication, and implementation issues are discussed vis-à-vis two examples of implantable microimagers; the retinal prosthesis and in vivo neuro-microimager. Testing of these devices in animals verify the use of the microimagers in the implanted state. We believe that further advancement of these devices will lead to the development of a new method for medical and scientific applications. PMID:27879873

  1. Clinical experience with the transvenous Medtronic Pacer Cardioverter Defibrillator (PCD) System.

    PubMed Central

    Golino, A; Pappone, C; Panza, A; Santomauro, M; Iorio, D; De Amicis, V; Chiariello, M; Spampinato, N

    1993-01-01

    We review our experience with the transvenous Medtronic Pacer Cardioverter Defibrillator System (Model 7217B), a multifunction implantable pacer defibrillator combined with a transvenous lead system (Transvene). From April 1991 to October 1992, we implanted this device in 19 consecutive patients (11 men and 8 women; average age, 56.5 years). Nine patients (47.4%), 5 with coronary artery disease and 4 with dilated cardiomyopathy, had an ejection fraction of < 30%. The average operative time was 129 minutes. In 18 patients (94.7%), the transvenous lead system provided effective sensing, pacing, and defibrillation during intraoperative testing. In each of these cases, the defibrillation threshold was less than 18 J. In 1 patient (5.3%), it was necessary to switch to epicardial leads, which were implanted through a left thoracotomy. All patients were extubated in the recovery room. The average hospital stay was 8 days. There was no early mortality or morbidity. During a maximum follow-up period of 17 months (mean, 9.2 months), no sudden death occurred. The implantable system terminated 245 ventricular tachycardia episodes in 14 patients (73.7%) and 82 ventricular fibrillation episodes in 13 patients (68.4%). Two hundred eleven (86.1%) of the ventricular tachycardia episodes were resolved by antitachycardia pacing alone. In 2 patients (10.5%), the caval electrode became dislocated; repositioning of the electrode was followed by repeat defibrillation threshold evaluation. Our experience shows that the transvenous Medtronic Pacer Cardioverter Defibrillator System provides safe, effective treatment of ventricular tachyarrhythmias. Because the perioperative mortality and morbidity are extremely low, use of this device may be particularly beneficial in patients with a high operative risk. Moreover, the lower number of unpleasant therapeutic shocks should increase patient a acceptance of the device. Images PMID:8298322

  2. Automatism

    PubMed Central

    McCaldon, R. J.

    1964-01-01

    Individuals can carry out complex activity while in a state of impaired consciousness, a condition termed “automatism”. Consciousness must be considered from both an organic and a psychological aspect, because impairment of consciousness may occur in both ways. Automatism may be classified as normal (hypnosis), organic (temporal lobe epilepsy), psychogenic (dissociative fugue) or feigned. Often painstaking clinical investigation is necessary to clarify the diagnosis. There is legal precedent for assuming that all crimes must embody both consciousness and will. Jurists are loath to apply this principle without reservation, as this would necessitate acquittal and release of potentially dangerous individuals. However, with the sole exception of the defence of insanity, there is at present no legislation to prohibit release without further investigation of anyone acquitted of a crime on the grounds of “automatism”. PMID:14199824

  3. A multifilamented electrode in the middle cardiac vein reduces energy requirements for defibrillation in the pig

    PubMed Central

    Roberts, P; Allen, S; Betts, T; Urban, J; Euler, D; Crick, S; Anderson, R; Kallok, M; Morgan, J

    2000-01-01

    OBJECTIVE—To compare the defibrillation efficacy of a novel lead system placed in the middle cardiac vein with a conventional non-thoracotomy lead system.
METHODS—In eight pigs (weighing 35-71 kg), an electrode was advanced transvenously to the right ventricular apex (RV), with the proximal electrode in the superior caval vein (SCV). Middle cardiac vein (MCV) angiography was used to delineate the anatomy before a three electrode system (length 2 × 25 mm + 1 × 50 mm) was positioned in the vein. An active housing (AH) electrode was implanted in the left pectoral region. Ventricular fibrillation was induced and biphasic shocks were delivered by an external defibrillator. The defibrillation threshold was measured and the electrode configurations randomised to: RV→AH, RV+MCV→AH, MCV→AH, and RV→SCV+AH.
RESULTS—For these configurations, mean (SD) defibrillation thresholds were 27.3 (9.6) J, 11.9 (2.9) J, 15.2 (4.3) J, and 21.8 (9.3) J, respectively. Both electrode configurations incorporating the MCV had defibrillation thresholds that were significantly less than those observed with the RV→AH (p < 0.001) and RV→SCV+AH (p < 0.05) configurations. Necropsy dissection showed that the MCV drained into the coronary sinus at a location close to its orifice (mean distance = 2.7 (2.2) mm). The MCV bifurcated into two main branches that drained the right and left ventricles, the left branch being the dominant vessel in the majority (6/7) of cases.
CONCLUSIONS—Placement of specialised defibrillation electrodes within the middle cardiac vein provides more effective defibrillation than a conventional tight ventricular lead.


Keywords: ventricular defibrillation; defibrillation threshold; implantable cardioverter defibrillator; middle cardiac vein PMID:10995416

  4. Use of Automated External Defibrillators

    SciTech Connect

    Gregory K Christensen

    2009-02-01

    In an effort to improve survival from cardiac arrest, the American Heart Association (AHA) has promoted the Chain of Survival concept, describing a sequence of prehospital steps that result in improved survival after sudden cardiac arrest. These interventions include immediate deployment of emergency medical services, prompt cardiopulmonary resuscitation, early defibrillation when indicated, and early initiation of advanced medical care. Early defibrillation has emerged as the most important intervention with survival decreasing by 10% with each minute of delay in defibrillation. Ventricular Fibrillation (VF) is a condition in which there is uncoordinated contraction of the heart cardiac muscle of the ventricles in the heart, making them tremble rather than contract properly. VF is a medical emergency and if the arrhythmia continues for more than a few seconds, blood circulation will cease, and death can occur in a matter of minutes. During VF, contractions of the heart are not synchronized, blood flow ceases, organs begin to fail from oxygen deprivation and within 10 minutes, death will occur. When VF occurs, the victim must be defibrillated in order to establish the heart’s normal rhythm. On average, the wait for an ambulance in populated areas of the United States is about 11 minutes. In view of these facts, the EFCOG Electrical Safety Task Group initiated this review to evaluate the potential value of deployment and use of automated external defibrillators (AEDs) for treatment of SCA victims. This evaluation indicates the long term survival benefit to victims of SCA is high if treated with CPR plus defibrillation within the first 3-5 minutes after collapse. According to the American Heart Association (AHA), survival rates as high as 74% are possible if treatment and defibrillation is performed in the first 3 minutes. In contrast survival rates are only 5% where no AED programs have been established to provide prompt CPR and defibrillation. ["CPR statistics

  5. Reuse of pacemakers, defibrillators and cardiac resynchronisation devices

    PubMed Central

    Sakthivel, R; Satheesh, Santhosh; Ananthakrishna Pillai, Ajith; Sagnol, Pascal; Jouven, Xavier; Dodinot, Bernard; Balachander, Jayaraman

    2017-01-01

    Objective Access to pacemakers remains poor among many patients in low/middle-income countries. Reuse of explanted pacemakers is a possible solution, but is still not widespread because of concerns regarding outcomes, especially infection. Our objective was to study early outcomes with implants using reused devices and compare them with those with implants using new devices. Methods We studied all patients who underwent implantation of a new or reused pacemaker, cardiac resynchronisation therapy (CRT) device or implantable cardioverter defibrillator (ICD) in the last 5 years at a single institution. We analysed outcomes related to infection, device malfunction and device-related death within 6 months after initial implantation. Results During the study period, 887 patients underwent device implant, including 127 CRT devices or ICDs. Of these, 260 devices (29.3%) were reused and the others were new. At 6 months, there were three device-related infections in implants using a new device. There were no infections among patients receiving a reused device. There were no device malfunctions or device-related deaths in either group. Conclusions We found no difference in rate of infection or device malfunction among patients getting a reused device as compared with those with a new device. This study reinforces the safety of reusing devices for implant including CRT and ICDs. PMID:28176981

  6. [Primary prevention of sudden cardiac death through a wearable cardioverter-defibrillator].

    PubMed

    Gabrielli, Domenico; Benvenuto, Manuela; Baroni, Matteo; Oliva, Fabrizio; Capucci, Alessandro

    2015-01-01

    Nowadays, the implantable cardioverter-defibrillator is the gold standard for the prevention of sudden cardiac death due to tachyarrhythmias. However, its use is not free from short and long-term risks. In the last years, the wearable cardioverter-defibrillator (WCD) has become a widespread option for patients who need a safe and reversible protection against ventricular tachyarrhythmias. Notwithstanding this, its everyday application is restricted by several limitations, including the risk of inappropriate shocks, the device size and the need for strict compliance of both patients and caregivers. In this review, we report the most relevant literature data on WCD usage along with the main fields of applications and future perspectives.

  7. Complex Tricuspid Valve Repair in Patients With Pacer Defibrillator-Related Tricuspid Regurgitation.

    PubMed

    Raman, Jaishankar; Sugeng, Lissa; Lai, David T M; Jeevanandam, Valluvan

    2016-04-01

    Tricuspid valve regurgitation in patients with heart failure or in those undergoing complex cardiac operations is associated with increased morbidity and mortality. We report our results with a technique of repairing the tricuspid valves while retaining the pacer defibrillator lead. Patients had tricuspid valve repairs that included repositioning of the pacer defibrillator lead, approximation of septal and inferior/posterior leaflets in a modified cleft repair, and implantation of a tricuspid annuloplasty ring. This procedure was performed in more than 42 patients with good success.

  8. Differential effects of defibrillation on systemic and cardiac sympathetic activity

    PubMed Central

    Bode, F; Wiegand, U; Raasch, W; Richardt, G; Potratz, J

    1998-01-01

    Objective—To assess the effect of defibrillation shocks on cardiac and circulating catecholamines.
Design—Prospective examination of myocardial catecholamine balance during dc shock by simultaneous determination of arterial and coronary sinus plasma concentrations. Internal countershocks (10-34 J) were applied in 30 patients after initiation of ventricular fibrillation for a routine implantable cardioverter defibrillator test. Another 10 patients were externally cardioverted (50-360 J) for atrial fibrillation.
Main outcome measures—Transcardiac noradrenaline, adrenaline, and lactate gradients immediately after the shock.
Results—After internal shock, arterial noradrenaline increased from a mean (SD) of 263 (128) pg/ml at baseline to 370 (148) pg/ml (p = 0.001), while coronary sinus noradrenaline fell from 448 (292) to 363 (216) pg/ml (p = 0.01), reflecting a shift from cardiac net release to net uptake. After external shock delivery, there was a similar increase in arterial noradrenaline, from 260 (112) to 459 (200) pg/ml (p = 0.03), while coronary sinus noradrenaline remained unchanged. Systemic adrenaline increased 11-fold after external shock (p = 0.01), outlasting the threefold rise following internal shock (p = 0.001). In both groups, a negative transmyocardial adrenaline gradient at baseline decreased further, indicating enhanced myocardial uptake. Cardiac lactate production occurred after ventricular fibrillation and internal shock, but not after external cardioversion, so the neurohumoral changes resulted from the defibrillation process and not from alterations in oxidative metabolism.
Conclusions—A dc shock induces marked systemic sympathoadrenal and sympathoneuronal activation, but attenuates cardiac sympathetic activity. This might promote the transient myocardial depression observed after electrical discharge to the heart.

 Keywords: defibrillation;  autonomic cardiac function;  catecholamines;  lactate

  9. Automated external defibrillation: laboratory evaluation.

    PubMed

    Rosenthal, E; Carroll, D; Vincent, R; Chamberlain, D A

    1984-04-01

    Twelve samples of ventricular fibrillation were fed into nine automated external defibrillator-pacemakers ( AEDP , "Heart Aid") of recent design. All the devices recognised and defibrillated ventricular fibrillation in seven of the samples within 30 sec. None of the devices reacted to two of the samples; in the remaining three there was inter-device variation ranging from an appropriate response to no response, as well as inappropriate pacing or delay in recognition and treatment. Poor recognition of some ventricular fibrillation waveforms with considerable inter-device variation limits the usefulness of this model. A new prototype responded more consistently and future models may be of value in community resuscitation. The difficulty of evaluating the diagnostic capability of AEDP devices in clinical use makes comprehensive laboratory testing essential prior to release.

  10. Prospective multicenter randomized trial of fast ventricular tachycardia termination by prolonged versus conventional anti-tachyarrhythmia burst pacing in implantable cardioverter-defibrillator patients-Atp DeliVery for pAiNless ICD thErapy (ADVANCE-D) Trial results

    PubMed Central

    Lunati, Maurizio; Defaye, Pascal; Mermi, Johann; Proclemer, Alessandro; del Castillo-Arroys, Silvia; Molon, Giulio; Santi, Elisabetta; De Santo, Tiziana; Navarro, Xavier; Kloppe, Axel

    2010-01-01

    Purpose The purpose of the trial was to quantify and compare the efficacy of two different sequences of burst anti-tachycardia pacing (ATP) strategies for the termination of fast ventricular tachycardia. Methods The trial was prospective, multicenter, parallel and randomized, enrolling patients with an indication for implantable cardioverter-defibrillator implantation. Results From February 2004, 925 patients were randomized and followed-up for 12 months. Eight pulses ATP terminated 64% of episodes vs. 70% in the 15-pulse group (p = 0.504). Fifteen pulses proved significantly better in patients without a previous history of heart failure (p = 0.014) and in patients with LVEF ≥ 40% (p = 0.016). No significant differences between groups were observed with regard to syncope/near-syncope occurrence. Conclusion In the general population, 15-pulse ATP is as effective and safe as eight-pulse ATP. The efficacy of ATP on fast ventricular arrhythmias confirmed once more the striking importance of careful device programming in order to reduce painful shocks. PMID:20087760

  11. Iranian Patients’ Experiences of the Internal Cardioverter Defibrillator Device Shocks: a Qualitative Study

    PubMed Central

    Pasyar, Nilofar; Sharif, Farkhondeh; Rakhshan, Mahnaz; Nikoo, Mohammad; Navab, Elham

    2015-01-01

    Introduction: Implantable Cardioverter Defibrillator (ICD) is a valuable treatment for the patients at risk of sudden cardiac death. In this method, after diagnosis of pathological cardiac rhythms, shock is automatically applied to normalize the rhythms. Shock is discharged when the patients are conscious, but the patients’ experiences of shock have remained unknown. Thus, this study aimed to identify and describe the patients’ experiences of shocks received from ICD. Methods: The present qualitative study was conducted through thematic analysis and semi-structured interviews on 9 patients mean age 41.55 (1.57) with ICD from November 2013 to July 2014. Data analysis was also performed simultaneously using constant comparative analysis. Results: In this study, two main themes, namely "with a parachute for life" and "Faced with nuisance", were obtained representing the patients’ experiences regarding ICD shock. With a parachute for life included subthemes, such as "Rebirth", "Comforter and healing", and "Life assurance". In addition, "Faced with nuisance" consisted of 2 subthemes of "Discomfort in moments of shock" and "Displeasure after shock". Conclusion: This study provided a basis for evaluation of patients nursing after discharge. By identification of the patients’ experiences regarding shock, the present study can help the professional health staff to efficiently play their roles and provide patients with holistic care. It can also be effective in designing behavioral and cognitive interventional programs to change the patients’ attitude and promote their adaptation with their conditions. PMID:26744727

  12. Evaluation of electrode polarity on defibrillation efficacy.

    PubMed

    Bardy, G H; Ivey, T D; Allen, M D; Johnson, G; Greene, H L

    1989-02-15

    The effect of electrode polarity on defibrillation thresholds in humans is unknown. This prospective, randomized evaluation of electrode polarity on defibrillation thresholds was performed in 21 survivors of ventricular fibrillation (VF) undergoing cardiac surgery. Defibrillation was always performed with 2 identical large rectangular, wire mesh electrodes positioned over the anterior wall of the right ventricle and the posterolateral wall of the left ventricle. The initial electrode polarity for the left ventricular (LV) electrode was chosen randomly for determination of the defibrillation threshold. Subsequently, electrode polarity was reversed. The defibrillation threshold was defined as the lowest pulse amplitude that would effectively terminate VF with a single discharge delivered 10 seconds after initiation of an episode of VF with alternating current. For each defibrillation pulse, voltage, current, resistance and delivered energy were recorded. Of the 21 patients, 15 (71%) had a lower defibrillation threshold when the LV electrode was positive, 2 patients (10%) had a lower defibrillation threshold when the LV electrode was negative and 4 patients (19%) had equal defibrillation thresholds (within 0.5 J) regardless of polarity. The mean leading edge defibrillation threshold voltage was 370 +/- 88 volts when the LV electrode was negative and 320 +/- 109 volts (14% less) when the LV electrode was positive (p = 0.014). Mean leading edge defibrillation threshold current was 9.3 +/- 3.1 amps when the LV electrode was negative compared to 7.7 +/- 3.1 amps (17% less) when the LV electrode was positive (p = 0.0033). There were no differences in resistance with the 2 configurations.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Position paper for management of elderly patients with pacemakers and implantable cardiac defibrillators: Groupe de Rythmologie et Stimulation Cardiaque de la Société Française de Cardiologie and Société Française de Gériatrie et Gérontologie.

    PubMed

    Fauchier, Laurent; Alonso, Christine; Anselme, Frederic; Blangy, Hugues; Bordachar, Pierre; Boveda, Serge; Clementy, Nicolas; Defaye, Pascal; Deharo, Jean-Claude; Friocourt, Patrick; Gras, Daniel; Halimi, Franck; Klug, Didier; Mansourati, Jacques; Obadia, Benjamin; Pasquié, Jean-Luc; Pavin, Dominique; Sadoul, Nicolas; Taieb, Jerome; Piot, Olivier; Hanon, Olivier

    2016-10-01

    Despite the increasingly high rate of implantation of pacemakers (PMs) and implantable cardioverter defibrillators (ICDs) in elderly patients, data supporting their clinical and cost-effectiveness in this age stratum are ambiguous and contradictory. We reviewed the data regarding the applicability, safety and effectiveness of conventional pacing, ICDs and cardiac resynchronization therapy (CRT) in elderly patients. Although periprocedural risk may be slightly higher in the elderly, the implantation procedure for PMs and ICDs is still relatively safe in this age group. In older patients with sinus node disease, the general consensus is that DDD pacing with the programming of an algorithm to minimize ventricular pacing is preferred. In very old patients presenting with intermittent or suspected atrioventricular block, VVI pacing may be appropriate. In terms of correcting potentially life-threatening arrhythmias, the effectiveness of ICD therapy is similar in older and younger individuals. However, the assumption of persistent ICD benefit in the elderly population is questionable, as any advantageous effect of the device on arrhythmic death may be attenuated by higher total non-arrhythmic mortality. While septuagenarians and octogenarians have higher annual all-cause mortality rates, ICD therapy may remain effective in selected patients at high risk of arrhythmic death and with minimum comorbidities despite advanced age. ICD implantation among the elderly, as a group, may not be cost-effective, but the procedure may reach cost-effectiveness in those expected to live more than 5-7years after implantation. Elderly patients usually experience significant functional improvement after CRT, similar to that observed in middle-aged patients. Management of CRT non-responders remains globally the same, while considering a less aggressive approach in terms of reinterventions (revision of left ventricular [LV] lead placement, addition of a right ventricular or LV lead, LV

  14. Position paper for management of elderly patients with pacemakers and implantable cardiac defibrillators Groupe de rythmologie et stimulation cardiaque de la Société française de cardiologie et Société française de gériatrie et gérontologie.

    PubMed

    Fauchier, Laurent; Alonso, Christine; Anselme, Frédéric; Blangy, Hugues; Bordachar, Pierre; Boveda, Serge; Clementy, Nicolas; Defaye, Pascal; Deharo, Jean-Claude; Friocourt, Patrick; Gras, Daniel; Halimi, Franck; Klug, Didier; Mansourati, Jacques; Obadia, Benjamin; Pasquié, Jean-Luc; Pavin, Dominique; Sadoul, Nicolas; Taieb, Jérôme; Piot, Olivier; Hanon, Olivier

    2016-09-01

    Despite the increasingly high rate of implantation of pacemakers (PM) and cardioverter-defibrillators (ICD) in elderly patients, data supporting their clinical and cost-effectiveness in this age stratum are ambiguous and contradictory. We reviewed the data regarding the applicability, safety, and effectiveness of the conventional pacing, ICD and cardiac resynchronization therapy (CRT) in elderly patients. Although peri-procedural risk may be slightly higher in the elderly, the procedure of implantation of PMs and ICDs is still relatively safe in this age group. In older patients with sinus node disease, a general consensus is that dual chamber pacing, along with the programming of an algorithm to minimise ventricular pacing is preferred. In very old patients presenting with intermittent or suspected AV block, VVI pacing may be appropriate. In terms of correcting potentially life-threatening arrhythmias, the effectiveness of ICD therapy is comparable in older and younger individuals. However, the assumption of persistent ICD benefit in the elderly population is questionable, as any advantage of the device on arrhythmic death may be attenuated by a higher total non-arrhythmic mortality. While septuagenarians and octogenarians have higher annual all-cause mortality rates, ICD therapy may remain effective in selected patients at high risk of arrhythmic death and with minimum comorbidities despite advanced age. ICD implantation among the elderly, as a group, may not be cost-effective, but the procedure may reach cost-effectiveness in those expected to live >5-7 years after implantation. The elderly patients usually experience a significant functional improvement after CRT, similar to that observed in middle-aged patients. Management of CRT non responders remains globally the same, while considering a less aggressive approach in terms of re interventions (revision of LV lead placement, addition of a RV or LV lead, LV endocardial pacing configuration). Overall, age

  15. Electrical Heart Defibrillation with Ion Channel Blockers

    NASA Astrophysics Data System (ADS)

    Feeney, Erin; Clark, Courtney; Puwal, Steffan

    Heart disease is the leading cause of mortality in the United States. Rotary electrical waves within heart muscle underlie electrical disorders of the heart termed fibrillation; their propagation and breakup leads to a complex distribution of electrical activation of the tissue (and of the ensuing mechanical contraction that comes from electrical activation). Successful heart defibrillation has, thus far, been limited to delivering large electrical shocks to activate the entire heart and reset its electrical activity. In theory, defibrillation of a system this nonlinear should be possible with small electrical perturbations (stimulations). A successful algorithm for such a low-energy defibrillator continues to elude researchers. We propose to examine in silica whether low-energy electrical stimulations can be combined with antiarrhythmic, ion channel-blocking drugs to achieve a higher rate of defibrillation and whether the antiarrhythmic drugs should be delivered before or after electrical stimulation has commenced. Progress toward a more successful, low-energy defibrillator will greatly minimize the adverse effects noted in defibrillation and will assist in the development of pediatric defibrillators.

  16. An artifact-robust, shape library-based algorithm for automatic segmentation of inner ear anatomy in post-cochlear-implantation CT.

    PubMed

    Reda, Fitsum A; Noble, Jack H; Labadie, Robert F; Dawant, Benoit M

    2014-03-21

    A cochlear implant (CI) is a device that restores hearing using an electrode array that is surgically placed in the cochlea. After implantation, the CI is programmed to attempt to optimize hearing outcome. Currently, we are testing an image-guided CI programming (IGCIP) technique we recently developed that relies on knowledge of relative position of intracochlear anatomy to implanted electrodes. IGCIP is enabled by a number of algorithms we developed that permit determining the positions of electrodes relative to intra-cochlear anatomy using a pre- and a post-implantation CT. One issue with this technique is that it cannot be used for many subjects for whom a pre-implantation CT was not acquired. Pre-implantation CT has been necessary because it is difficult to localize the intra-cochlear structures in post-implantation CTs alone due to the image artifacts that obscure the cochlea. In this work, we present an algorithm for automatically segmenting intra-cochlear anatomy in post-implantation CTs. Our approach is to first identify the labyrinth and then use its position as a landmark to localize the intra-cochlea anatomy. Specifically, we identify the labyrinth by first approximately estimating its position by mapping a labyrinth surface of another subject that is selected from a library of such surfaces and then refining this estimate by a standard shape model-based segmentation method. We tested our approach on 10 ears and achieved overall mean and maximum errors of 0.209 and 0.98 mm, respectively. This result suggests that our approach is accurate enough for developing IGCIP strategies based solely on post-implantation CTs.

  17. An artifact-robust, shape library-based algorithm for automatic segmentation of inner ear anatomy in post-cochlear-implantation CT

    NASA Astrophysics Data System (ADS)

    Reda, Fitsum A.; Noble, Jack H.; Labadie, Robert F.; Dawant, Benoit M.

    2014-03-01

    A cochlear implant (CI) is a device that restores hearing using an electrode array that is surgically placed in the cochlea. After implantation, the CI is programmed to attempt to optimize hearing outcome. Currently, we are testing an imageguided CI programming (IGCIP) technique we recently developed that relies on knowledge of relative position of intracochlear anatomy to implanted electrodes. IGCIP is enabled by a number of algorithms we developed that permit determining the positions of electrodes relative to intra-cochlear anatomy using a pre- and a post-implantation CT. One issue with this technique is that it cannot be used for many subjects for whom a pre-implantation CT was not acquired. Pre-implantation CT has been necessary because it is difficult to localize the intra-cochlear structures in post-implantation CTs alone due to the image artifacts that obscure the cochlea. In this work, we present an algorithm for automatically segmenting intra-cochlear anatomy in post-implantation CTs. Our approach is to first identify the labyrinth and then use its position as a landmark to localize the intra-cochlea anatomy. Specifically, we identify the labyrinth by first approximately estimating its position by mapping a labyrinth surface of another subject that is selected from a library of such surfaces and then refining this estimate by a standard shape model-based segmentation method. We tested our approach on 10 ears and achieved overall mean and maximum errors of 0.209 and 0.98 mm, respectively. This result suggests that our approach is accurate enough for developing IGCIP strategies based solely on post-implantation CTs.

  18. Study of Cardiac Defibrillation Through Numerical Simulations

    NASA Astrophysics Data System (ADS)

    Bragard, J.; Marin, S.; Cherry, E. M.; Fenton, F. H.

    Three-dimensional numerical simulations of the defibrillation problem are presented. In particular, in this study we use the rabbit ventricular geometry as a realistic model system for evaluating the efficacy of defibrillatory shocks. Statistical data obtained from the simulations were analyzed in term of a dose-response curve. Good quantitative agreement between our numerical results and clinically relevant values is obtained. An electric field strength of about 6.6 V/cm indicates a fifty percent probability of successful defibrillation for a 12-ms monophasic shock. Our validated model will be useful for optimizing defibrillation protocols.

  19. [Public access defibrillation in the Sorrento Peninsula].

    PubMed

    Santomauro, Maurizio; Giordano, Raffaele; Poli, Vincenzo; Iaccarino, Vincenzo; Palagiano, Francesco; Matarazzo, Luigi; Langella, Giuseppina; Riganti, Carla; Vosa, Carlo

    2012-10-01

    Early cardiac defibrillation is the only effective therapy to stop ventricular fibrillation or pulseless ventricular tachycardia. It is still considered the gold standard for the treatment of ventricular tachycardia/fibrillation, and is the only intervention capable of improving survival in cardiac arrest survivors. Timing of intervention, however, is crucial because after only 10 min success rates are very low (0-2%). Unfortunately, adequate relief cannot always be provided within the necessary time. The purpose of the public access defibrillation project in Sorrento was to create fixed and mobile first aid with automated external defibrillators in combination with the local 118 emergency system. With the involvement of pharmacies, bathing establishments and schools, 31 equally distant sites for public access defibrillation were made available. This organization was supplemented by mobile units on the cars of the Municipal Police and Civil Protection, and on patrol boats in the harbor.

  20. Optogenetic defibrillation terminates ventricular arrhythmia in mouse hearts and human simulations

    PubMed Central

    Boyle, Patrick M.; Vogt, Christoph C.; Karathanos, Thomas V.; Arevalo, Hermenegild J.; Fleischmann, Bernd K.; Trayanova, Natalia A.

    2016-01-01

    Ventricular arrhythmias are among the most severe complications of heart disease and can result in sudden cardiac death. Patients at risk currently receive implantable defibrillators that deliver electrical shocks to terminate arrhythmias on demand. However, strong electrical shocks can damage the heart and cause severe pain. Therefore, we have tested optogenetic defibrillation using expression of the light-sensitive channel channelrhodopsin-2 (ChR2) in cardiac tissue. Epicardial illumination effectively terminated ventricular arrhythmias in hearts from transgenic mice and from WT mice after adeno-associated virus–based gene transfer of ChR2. We also explored optogenetic defibrillation for human hearts, taking advantage of a recently developed, clinically validated in silico approach for simulating infarct-related ventricular tachycardia (VT). Our analysis revealed that illumination with red light effectively terminates VT in diseased, ChR2-expressing human hearts. Mechanistically, we determined that the observed VT termination is due to ChR2-mediated transmural depolarization of the myocardium, which causes a block of voltage-dependent Na+ channels throughout the myocardial wall and interrupts wavefront propagation into illuminated tissue. Thus, our results demonstrate that optogenetic defibrillation is highly effective in the mouse heart and could potentially be translated into humans to achieve nondamaging and pain-free termination of ventricular arrhythmia. PMID:27617859

  1. Case report: use caution when applying magnets to pacemakers or defibrillators for surgery.

    PubMed

    Schulman, Peter M; Rozner, Marc A

    2013-08-01

    The application of a magnet to a pacemaker (intended to cause asynchronous pacing) or implanted cardioverter defibrillator (intended to prevent shocks) during surgery without a clear understanding of actual magnet function(s) or precautions can have unexpected, untoward, or harmful consequences. In this report, we present 3 cases in which inadequate assessment of cardiac implanted electronic device (CIED) function, coupled with magnet application, contributed to or resulted in inappropriate antitachycardia pacing or shocks, CIED damage, or patient injury. Although these cases might be rare, they reinforce the need for a timely, detailed preoperative review of CIED function and programming as recommended by the American Society of Anesthesiologists and the Heart Rhythm Society.

  2. The Entirely Subcutaneous Defibrillator – A New Generation and Future Expectations

    PubMed Central

    Ali, Hussam; Lupo, Pierpaolo; Cappato, Riccardo

    2015-01-01

    Although conventional implantable cardioverter-defibrillators (ICDs) have proved effective in the prevention of sudden cardiac death (SCD), they still appear to be limited by non-trivial acute and long-term complications. The recent advent of an entirely subcutaneous ICD (S-ICD) represents a further step in the evolution of defibrillation technology towards a less-invasive approach. This review highlights some historical and current issues concerning the S-ICD that may offer a viable therapeutic option in selected patients at high risk of SCD and in whom pacing is not required. After the CE Mark and US Food and Drug Administration (FDA) approvals, the S-ICD is being implanted worldwide with growing clinical data regarding its safety and efficacy (the EFFORTLESS Registry). The recently developed new generation of S-ICD (EMBLEM, Boston Scientific) demonstrates favourable features including a smaller device, longer longevity and remote-monitoring compatibility. Further innovations in the S-ICD system and potential integration with leadless pacing may play an important role in defibrillation therapy and prevention of SCD in the near future. PMID:26835112

  3. Technologic advances and program initiatives in public access defibrillation using automated external defibrillators.

    PubMed

    White, R D

    2001-06-01

    Widespread provision of early defibrillation following cardiac arrest holds major promise for improved survival from ventricular fibrillation. The critical element in predicting a successful outcome is the rapidity with which defibrillation is achieved. A worldwide awareness of this potential and its advocacy by such organizations as the American Heart Association have been pivotal in the evolution of initiatives to make defibrillation more widely and more rapidly available. The feasibility of this initiative, known as public access defibrillation, is in large measure a direct consequence of major technologic advances in automated external defibrillators (AEDs). New low-energy waveforms with biphasic morphology have been shown to be more effective in terminating ventricular fibrillation and may do so with less myocardial injury. Placement of AEDs in a variety of nontraditional settings such as police cars, aircraft and airport terminals, and gambling casinos has been shown to yield an impressive number of survivors of cardiac arrest in ventricular fibrillation. Questions yet to be answered center on the appropriate disposition of AEDs in public access defibrillation settings, training and retraining issues, device maintenance, and collection of accurate data to document benefit and to identify areas of needed improvement or expansion of AED availability.

  4. 75 FR 70015 - External Defibrillators; Public Workshop

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-16

    ... unexpectedly stops pumping blood to the body. When normal heart rhythms are not restored quickly, sudden... the past 5 years we have seen persistent safety problems with all types of external defibrillators... time period. Many of the types of problems we have identified are preventable, correctable, and...

  5. Management of radiation therapy patients with cardiac defibrillator or pacemaker.

    PubMed

    Salerno, Francesca; Gomellini, Sara; Caruso, Cristina; Barbara, Raffaele; Musio, Daniela; Coppi, Tamara; Cardinale, Mario; Tombolini, Vincenzo; de Paula, Ugo

    2016-06-01

    The increasing growth of population with cardiac implantable electronic devices (CIEDs) such as Pacemaker (PM) and Implantable Cardiac Defibrillators (ICD), requires particular attention in management of patients needing radiation treatment. This paper updates and summarizes some recommendations from different international guidelines. Ionizing radiation and/or electromagnetic interferences could cause device failure. Current approaches to treatment in patients who have these devices vary among radiation oncology centres. We refer to the German Society of Radiation Oncology and Cardiology guidelines (ed. 2015); to the Society of Cardiology Australia and New Zealand Statement (ed. 2015); to the guidelines in force in the Netherlands (ed. 2012) and to the Italian Association of Radiation Oncology recommendations (ed. 2013) as reported in the guidelines for the treatment of breast cancer in patients with CIED. Although there is not a clear cut-off point, risk of device failure increases with increasing doses. Cumulative dose and pacing dependency have been combined to categorize patients into low-, medium- and high-risk groups. Measures to secure patient safety are described for each category. The use of energy ≤6MV is preferable and it's strongly recommended not to exceed a total dose of 2 Gy to the PM and 1 Gy for ICD. Given the dangers of device malfunction, radiation oncology departments should adopt all the measures designed to minimize the risk to patients. For this reason, a close collaboration between cardiologist, radiotherapist and physicist is necessary.

  6. Electroporation induced by internal defibrillation shock with and without recovery in intact rabbit hearts.

    PubMed

    Wang, Yves T; Efimov, Igor R; Cheng, Yuanna

    2012-08-15

    Defibrillation shocks from implantable cardioverter defibrillators can be lifesaving but can also damage cardiac tissues via electroporation. This study characterizes the spatial distribution and extent of defibrillation shock-induced electroporation with and without a 45-min postshock period for cell membranes to recover. Langendorff-perfused rabbit hearts (n = 31) with and without a chronic left ventricular (LV) myocardial infarction (MI) were studied. Mean defibrillation threshold (DFT) was determined to be 161.4 ± 17.1 V and 1.65 ± 0.44 J in MI hearts for internally delivered 8-ms monophasic truncated exponential (MTE) shocks during sustained ventricular fibrillation (>20 s, SVF). A single 300-V MTE shock (twice determined DFT voltage) was used to terminate SVF. Shock-induced electroporation was assessed by propidium iodide (PI) uptake. Ventricular PI staining was quantified by fluorescent imaging. Histological analysis was performed using Masson's Trichrome staining. Results showed PI staining concentrated near the shock electrode in all hearts. Without recovery, PI staining was similar between normal and MI groups around the shock electrode and over the whole ventricles. However, MI hearts had greater total PI uptake in anterior (P < 0.01) and posterior (P < 0.01) LV epicardial regions. Postrecovery, PI staining was reduced substantially, but residual staining remained significant with similar spacial distributions. PI staining under SVF was similar to previously studied paced hearts. In conclusion, electroporation was spatially correlated with the active region of the shock electrode. Additional electroporation occurred in the LV epicardium of MI hearts, in the infarct border zone. Recovery of membrane integrity postelectroporation is likely a prolonged process. Short periods of SVF did not affect electroporation injury.

  7. Anatomic verification of automatic segmentation algorithms for precise intrascalar localization of cochlear implant electrodes in adult temporal bones using clinically-available computed tomography

    PubMed Central

    Schuman, Theodore A.; Noble, Jack H.; Wright, Charles G.; Wanna, George; Dawant, Benoit; Labadie, Robert F.

    2015-01-01

    Objectives/Hypothesis We have previously described a novel, automated, non-rigid, model-based method for determining the intrascalar position of cochlear implant (CI) electrodes arrays within human temporal bones using clinically available, flat-panel volume computed tomography (fpVCT). We sought to validate this method by correlating results with anatomic microdissection of CI arrays in cadaveric bones. Study Design Basic science. Methods Seven adult cadaveric temporal bones were imaged using fpVCT before and after electrode insertion. Using a statistical model of intra-cochlear anatomy an active shape model optimization approach was then used to identify the scala tympani and vestibuli on the pre-intervention fpVCT. The array position was estimated by identifying its midline on the post-intervention scan and superimposing it onto the pre-intervention images using rigid registration. Specimens were then microdissected to demonstrate the actual array position. Results Using microdissection as the standard for ascertaining electrode position, the automatic identifications of the basilar membrane coupled with post-intervention fpVCT for electrode position identification accurately depicted the array location in all seven bones. In four specimens, the array remained within the scala tympani; in three the basilar membrane was breached. Conclusions We have anatomically validated the automated method for predicting the intrascalar location of CI arrays using CT. Using this algorithm and pre- and post-intervention CT, rapid feedback regarding implant location and expected audiological outcomes could be obtained in clinical settings. PMID:20939074

  8. Automatic three-dimensional registration of intra-vascular optical coherence tomography images for the clinical evaluation of stent implantation over time

    NASA Astrophysics Data System (ADS)

    Ughi, Giovanni J.; Adriaenssens, Tom; Larsson, Matilda; Dubois, Christophe; Sinnaeve, Peter; Coosemans, Mark; Desmet, Walter; D'hooghe, Jan

    2012-01-01

    In the last decade a large number of new intracoronary devices (i.e. drug-eluting stents, DES) have been developed to reduce the risks related to bare metal stent (BMS) implantation. The use of this new generation of DES has been shown to substantially reduce, compared with BMS, the occurrence of restenosis and recurrent ischemia that would necessitate a second revascularization procedure. Nevertheless, safety issues on the use of DES persist and full understanding of mechanisms of adverse clinical events is still a matter of concern and debate. Intravascular Optical Coherence Tomography (IV-OCT) is an imaging technique able to visualize the microstructure of blood vessels with an axial resolution <20 μm. Due to its very high spatial resolution, it enables detailed in-vivo assessment of implanted devices and vessel wall. Currently, the aim of several major clinical trials is to observe and quantify the vessel response to DES implantation over time. However, image analysis is currently performed manually and corresponding images, belonging to different IV-OCT acquisitions, can only be matched through a very labor intensive and subjective procedure. The aim of this study is to develop and validate a new methodology for the automatic registration of IV-OCT datasets on an image level. Hereto, we propose a landmark based rigid registration method exploiting the metallic stent framework as a feature. Such a tool would provide a better understanding of the behavior of different intracoronary devices in-vivo, giving unique insights about vessel pathophysiology and performance of new generation of intracoronary devices and different drugs.

  9. Automatic detection of contrast injection on fluoroscopy and angiography for image guided trans-catheter aortic valve implantations (TAVI)

    NASA Astrophysics Data System (ADS)

    Liao, Rui; You, Wei; Yan, Michelle; John, Matthias

    2011-03-01

    Presentation of detailed anatomical structures via 3-D models helps navigation and deployment of the prosthetic valve in TAVI procedures. Fast and automatic contrast detection in the aortic root on X-ray images facilitates a seamless workflow to utilize the 3-D models by triggering 2-D/3-D registration automatically when motion compensation is needed. In this paper, we propose a novel method for automatic detection of contrast injection in the aortic root on fluoroscopic and angiographic sequences. The proposed method is based on histogram analysis and likelihood ratio test, and is robust to variations in the background, the density and volume of the injected contrast, and the size of the aorta. The performance of the proposed algorithm was evaluated on 26 sequences from 5 patients and 3 clinical sites, with 16 out of 17 contrast injections correctly detected and zero false detections. The proposed method is of general form and can be extended for detection of contrast injection in other organs and/or applications.

  10. Electrical injury during "hands on" defibrillation-A potential risk of internal cardioverter defibrillators?

    PubMed

    Stockwell, Beverley; Bellis, Gareth; Morton, Geraint; Chung, Karen; Merton, W Louis; Andrews, Neil; Smith, Gary B

    2009-07-01

    Despite clear guidance for the need for rescuers to avoid contact with a patient during external defibrillation, the advice regarding the potential dangers of rescuer contact during the firing of an internal cardioverter defibrillator [ICD] generally implies that such contact is safe. This case report describes documented nerve injury to a rescuer by a shock delivered from an ICD during chest compression on a patient in cardiac arrest. The authors also discuss the existing literature on the subject and make suggestions for future management.

  11. How Will Having an Implantable Cardioverter Defibrillator Affect My Lifestyle?

    MedlinePlus

    ... Household appliances, such as microwave ovens High-tension wires Metal detectors Industrial welders Electrical generators These devices ... could damage your ICD or shake loose the wires in your heart. Ask your doctor how much ...

  12. Interference detection in implantable defibrillators induced by therapeutic radiation therapy

    PubMed Central

    Uiterwaal, G.J.; Springorum, B.G.F.; Scheepers, E.; de Ruiter, G.S.; Hurkmans, C.W.

    2006-01-01

    Background Electromagnetic fields and ionising radiation during radiotherapy can influence the functioning of ICDs. Guidelines for radiotherapy treatment were published in 1994, but only based on experience with pacemakers. Data on the influence of radiotherapy on ICDs is limited. Objectives We determined the risk to ICDs of interference detection induced by radiotherapy. Methods In our study we irradiated 11 ICDs. The irradiation was performed with a 6 megavolt photon beam. In each individual device test, a total of 20 Gray was delivered in a fractionated fashion. During each irradiation the output stimulation rate was monitored and electrogram storage was activated. In case of interference the test was repeated with the ICD outside and the lead(s) inside and outside the irradiation field. Results With the ICD inside the irradiation field, interference detection was observed in all ICDs. This caused pacing inhibition or rapid ventricular pacing. Ventricular tachycardia (VT) or ventricular fibrillation (VF) detection occurred, which would have caused tachycardia-terminating therapy. If the ICD was placed outside the irradiation field, no interference was observed. Conclusion Interference by ionising radiation on the ICDs is demonstrated both on bradycardia and tachycardia therapy. This can have consequences for patients. Recommendations for radiotherapy are presented in this article. ImagesFigure 1Figure 5 PMID:25696559

  13. What Are the Risks of Having an Implantable Cardioverter Defibrillator?

    MedlinePlus

    ... to reprogram the device. If that doesn't work, you doctor might have to replace the ICD. The longer you have an ICD, the more likely it is that ... National Institutes of Health Department of Health and Human Services USA.gov

  14. How to Respond to an Implantable Cardioverter-Defibrillator Recall

    MedlinePlus

    ... of the American Heart Association Facebook Twitter My alerts Sign In Join Search for this keyword Search ... Volunteer Warning Signs Advanced Search Donate Circulation My alerts Sign In Join Facebook Twitter Home About this ...

  15. Sexual Health for Patients with an Implantable Cardioverter Defibrillator

    MedlinePlus

    ... of 1774 patients who had experienced an acute myocardial infarction 7 showed that sexual activity was a likely ... Maclure M , Sherwood JB , Tofler GH , Determinants of Myocardial Infarction Onset Study Investigators . Triggering myocardial infarction by sexual ...

  16. Pacemakers and Implantable Defibrillators - Multiple Languages: MedlinePlus

    MedlinePlus

    ... العربية) Pacemaker (Arabic) العربية Bilingual PDF Health Information Translations Chinese - Simplified (简体中文) Pacemaker 心脏起搏器 - 简体中文 (Chinese - Simplified) Bilingual PDF Health Information Translations Chinese - Traditional (繁體中文) Pacemaker 心臟起搏器 - 繁體中文 (Chinese - Traditional) ...

  17. Investigation of capacitor failures in an automated external defibrillator.

    PubMed

    Tan, K-S; Hinberg, I

    2002-09-01

    Over the past 2 years, the Canadian Medical Devices Bureau has received a number of reports of capacitor failures on the high voltage board of an automated external defibrillator. Twenty-five cases of broken capacitor leads were found during routine preventive maintenance by the biomedical engineering staff of the institutions reporting the incidents. The Bureau has carried out a laboratory investigation to determine the effect of missing capacitors on the energy delivered by the defibrillator and to assess whether these capacitor failures represent a significant risk to patients. Our findings indicate that the automated external defibrillator will not perform acceptably with two broken capacitors. They further suggest that, during preventive maintenance, operators should use a defibrillator analyser to measure the delivered energy output rather than using the internal energy measurement circuit within the automated external defibrillator.

  18. Insulation Failure of the Linox Defibrillator Lead: A Case Report and Retrospective Review of a Single Center Experience.

    PubMed

    Howe, Andrew J; McKeag, Nicholas A; Wilson, Carol M; Ashfield, Kyle P; Roberts, Michael J

    2015-06-01

    Implantable cardioverter defibrillator (ICD) lead insulation failure and conductor externalization have been increasingly reported. The 7.8F silicon-insulated Linox SD and Linox S ICD leads (Biotronik, Berlin, Germany) were released in 2006 and 2007, respectively, with an estimated 85,000 implantations worldwide. A 39-year-old female suffered an out-of-hospital ventricular fibrillation (VF) arrest with successful resuscitation. An ICD was implanted utilizing a single coil active fixation Linox(Smart) S lead (Biotronik, Berlin, Germany). A device-triggered alert approximately 3 years after implantation confirmed nonphysiological high rate sensing leading to VF detection. A chest X-ray showed an abnormality of the ICD lead and fluoroscopic screening confirmed conductor externalization proximal to the defibrillator coil. In view of the combined electrical and fluoroscopic abnormalities, urgent lead extraction and replacement were performed. A review of Linox (Biotronik) and Vigila (Sorin Group, Milan, Italy) lead implantations within our center (n = 98) identified 3 additional patients presenting with premature lead failure, 2 associated with nonphysiological sensed events and one associated with a significant decrease in lead impedance. All leads were subsequently removed and replaced. This case provides a striking example of insulation failure affecting the Linox ICD lead and, we believe, is the first to demonstrate conductor externalization manifesting both electrical and fluoroscopic abnormalities.

  19. Combined Standby Transvenous Defibrillator and Demand Pacemaker.

    DTIC Science & Technology

    1975-12-01

    AD-A097 441 CARDIAC CARE SYSTEMS INC RED BANK NJ F/B 6/5 COM13INED STANDBY TRANSVENOJS DEFIBRILLATOR AND DEMAND PACEMAKER--ETC(U) DEC 75 L RUBIN...Development Command Fort Detrick, Frederick, MD 21701 Contract Number DAMD17-74-C-4108. Cardiac Care Systems, Inc. 80 E. Front Street Red Bank , NJ...8217 Cardiac Care Systems, Inc. 4I 80 E. Front Street 61 3121A1j0.4 Red Bank , NJ 07701 a .0_ e- /i\\ - -__________ I1. CONTROLLING OFFICE NAME AND ADDRESS 1.)42

  20. [The early semiautomatic defibrillation: legislative Italian framing and medical-legal aspects].

    PubMed

    Fontana, Alessandro; Zancaner, Silvano

    2004-10-01

    Following Anglosaxon experience, automatic external defibrillators (AEDs), devices capable of automatically identifying a defibrillating rhythm and triggering a life-saving discharge, are now becoming widespread in Italy too. Their extremely simple functioning, and diagnostic sensitivity combined with diagnostic specificity all mean that AEDs can even be used by non-medical personnel (nurses) and, more extensively and after proper training, also by "first responders" who are not necessarily healthcare-related (red cross volunteers, members of the police force, firemen, etc.). In this sense Italian law no. 120/2001, enacted in the interests of the collectivity, and its later provisions approved at the conference of the Italian state and regional authorities in 2003, admits this type of application. AED safety assurance means that these devices can also be used by ordinary people who are not trained and have no specific obligations, but who suddenly find themselves in an emergency situation. However, medical personnel, paramedics and non-healthcare-related "first responders" trained in the use of AEDs, are required to apply them in suitable circumstances and, if they do not, may be accused of refusal to act in an official capacity, omission of first aid, and manslaughter.

  1. Economic impact of longer battery life of cardiac resynchronization therapy defibrillators in Sweden

    PubMed Central

    Gadler, Fredrik; Ding, Yao; Verin, Nathalie; Bergius, Martin; Miller, Jeffrey D; Lenhart, Gregory M; Russell, Mason W

    2016-01-01

    Objective The objective of this study was to quantify the impact that longer battery life of cardiac resynchronization therapy defibrillator (CRT-D) devices has on reducing the number of device replacements and associated costs of these replacements from a Swedish health care system perspective. Methods An economic model based on real-world published data was developed to estimate cost savings and avoided device replacements for CRT-Ds with longer battery life compared with devices with industry-standard battery life expectancy. Base-case comparisons were performed among CRT-Ds of three manufacturers – Boston Scientific Corporation, St. Jude Medical, and Medtronic – over a 6-year time horizon, as per the available clinical data. As a sensitivity analysis, we evaluated CRT-Ds as well as single-chamber implantable cardioverter defibrillator (ICD-VR) and dual-chamber implantable cardioverter defibrillator (ICD-DR) devices over a longer 10-year period. All costs were in 2015 Swedish Krona (SEK) discounted at 3% per annum. Results Base-case analysis results show that up to 603 replacements and up to SEK 60.4 million cumulative-associated costs could be avoided over 6 years by using devices with extended battery life. The pattern of savings over time suggests that savings are modest initially but increase rapidly beginning in the third year of follow-up with each year’s cumulative savings two to three times the previous year. Evaluating CRT-D, ICD-VR, and ICD-DR devices together over a longer 10-year period, the sensitivity analysis showed 2,820 fewer replacement procedures and associated cost savings of SEK 249.3 million for all defibrillators with extended battery life. Conclusion Extended battery life is likely to reduce device replacements and associated complications and costs, which may result in important cost savings and a more efficient use of health care resources as well as a better quality of life for heart failure patients in Sweden. PMID:27826203

  2. The use of automated external defibrillators and public access defibrillators in the mountains: official guidelines of the international commission for mountain emergency medicine ICAR-MEDCOM.

    PubMed

    Elsensohn, Fidel; Agazzi, Giancelso; Syme, David; Swangard, Michael; Facchetti, Gianluca; Brugger, Hermann

    2006-01-01

    In this article we propose guidelines for rational use of automated external defibrillators and public access defibrillators in the mountains. In cases of ventricular fibrillation and pulseless ventricular tachycardia, early defibrillation is the most effective therapy. Easy access to mountainous areas permits visitation by persons with high risks for sudden cardiac death, and medical trials show the benefit of exercising in moderate altitude. The introduction of public access defibrillators in popular areas in the mountains may lead to a reduction of fatal outcome of cardiac arrest. Public access defibrillators should be placed with priority in popular ski areas, in busy mountain huts and restaurants, at mass-participation events, and in remote but often-visited locations that do not have medical coverage. Automated external defibrillators should be available to first-responder groups and mountain-rescue teams. It is important that people know how to perform cardiopulmonary resuscitation and how to use public access defibrillators and automated external defibrillators.

  3. Comparison of single-biphasic versus sequential-biphasic shocks on defibrillation threshold in pigs.

    PubMed

    Csanadi, Z; Jones, D L; Wood, G K; Klein, G J

    1997-06-01

    Current generation implantable cardioverter defibrillators use monophasic, biphasic, or sequential pulse shocks, most of which truncate after a given time, dumping the remaining charge on the capacitor through an internal resistor. We hypothesized that having an additional current pathway, and delivering the majority of the remaining charge on a single capacitor to the two pathways using additional shock phases, would improve defibrillation efficacy. This hypothesis was tested by comparing DFTs using a simulated single capacitor, single-biphasic shock (two 5-ms pulses separated by 0.2 ms), delivered to coupled pairs of electrodes, to those using a sequential-biphasic shock (four 5-ms pulses separated by 0.2 ms) delivered to separate opposing electrodes, delivered from the same electrodes for both waveforms. In eight open-chest anesthetized pigs, four mesh electrodes (Medtronic TX-7, 6.5 cm2), were sutured on the epicardium of the anterior and posterior surfaces of each ventricle. Shocks were delivered from a 200-microF capacitor bank. Triplicate DFTs were obtained using each waveform in a randomized crossover design. Initial leading edge voltage (mean +/- SEM: 420 +/- 33 V vs 497 +/- 34 V; P < 0.05), initial peak current (4.8 +/- 0.4 A vs 13 +/- 1.1 A; P < 0.001), and delivered energy (16.9 +/- 2.6 J vs 30.4 +/- 5.3 J; P < 0.05) at the DFT were all significantly lower using sequential-biphasic shocks than those using single-biphasic shocks, respectively. We conclude that for direct heart defibrillation, it is worthwhile to combine sequential capability to biphasic shocks and deliver the remaining charge on the capacitor to the two different pathways.

  4. 21 CFR 870.5310 - Automated external defibrillator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... shock of a maximum of 360 joules of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart. An AED analyzes the patient's electrocardiogram, interprets...

  5. 21 CFR 870.5310 - Automated external defibrillator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... shock of a maximum of 360 joules of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart. An AED analyzes the patient's electrocardiogram, interprets...

  6. Development of a current-controlled defibrillator for clinical tests.

    PubMed

    Fischer, M; Schönegg, M; Schöchlin, J; Bolz, A

    2002-01-01

    The work presented here is only a part of the development for a new current-controlled defibrillator. In the diploma thesis "Development and construction of a current-controlled defibrillator for clinical tests" the most important part was the control and safety of the defibrillator. To ensure a safe circuit design, a risk-analysis and a Failure Mode and Effects Analysis (FMEA) were necessary. Another major part was the programming of a microcontroller in embedded C and a programmable logic device in Very High Speed Integrated Circuit Description Language (VHDL). The circuit had to be constructed, and the defibrillator was optically decoupled from the laptop for safety reasons. The waveform-data can be transmitted to the microcontroller from the laptop, and the logged data is then transmitted back.

  7. 21 CFR 870.5300 - DC-defibrillator (including paddles).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... heart or to terminate other cardiac arrhythmias. This generic type of device includes low energy... defibrillating the atria or ventricles of the heart or to terminate other cardiac arrhythmias. The device...

  8. 21 CFR 870.5300 - DC-defibrillator (including paddles).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... heart or to terminate other cardiac arrhythmias. This generic type of device includes low energy... defibrillating the atria or ventricles of the heart or to terminate other cardiac arrhythmias. The device...

  9. Minor Variations in Electrode Pad Placement Impact Defibrillation Success.

    PubMed

    Esibov, Alexander; Chapman, Fred W; Melnick, Sharon B; Sullivan, Joseph L; Walcott, Gregory P

    2016-01-01

    Defibrillation is essential for resuscitating patients with ventricular fibrillation (VF), but shocks often fail to defibrillate. We hypothesized that small variations in pad placement affect shock success, and that defibrillation waveform and shock dose could compensate for suboptimal pad placement. In 10 swine experiments, electrode pads were attached at 3 adjacent anterolateral positions, less than 3 centimeters apart. At each position, 24 episodes of VF were induced and shocked, 8 episodes for each of 3 defibrillation therapies. This resulted in 9 tested combinations of pad position and defibrillation therapy, with 80 episodes of VF for each combination. An episode consisted of 15 seconds of untreated VF, followed by a first shock and, if necessary, a repeat shock. Episodes were separated by four minutes of recovery. Both electrode pad position and therapy order were randomized by experiment. Primary outcome was defined as successful VF termination after the first shock; secondary outcome was the cumulative success of the first and second shocks. First shock efficacy varied widely across the 9 tested combinations of pad position and defibrillation therapy, ranging from 11.3% to 86.3%. When grouped by therapy, first shock efficacy varied significantly between the 3 pad positions: 38.3%, 48.3%, 36.7% (p = 0.02, ANOVA), and, when grouped by pad position, it varied significantly between therapies: 15.0%, 32.5%, 75.8% (p < 0.001, ANOVA). Cumulative 2-shock success varied significantly with therapy (p < 0.001, ANOVA) but not with pad position (p = 0.30, ANOVA). The lowest first shock success was at one position in 6 of 10 animals, at another position in 4 of 10 animals, and never at the third position. Small variations in pad placement can significantly affect defibrillation shock efficacy. However, anatomical variation between individuals and the challenging conditions of real-world resuscitations make optimal pad placement impractical. Suboptimal pad placement can

  10. Riata silicone defibrillation lead with normal electrical measures at routine ambulatory check: The role of high-voltage shock testing

    PubMed Central

    De Maria, Elia; Borghi, Ambra; Bonetti, Lorenzo; Fontana, Pier Luigi; Cappelli, Stefano

    2016-01-01

    AIM To describe our experience with shock testing for the evaluation of patients with Riata™ leads. METHODS Among 51 patients with normal baseline electrical parameters, 20 died during follow-up. Of the remaining 31 patients, 15 underwent the test: In 10 cases a defibrillation testing with ventricular fibrillation (VF) induction and in 5 cases a R-wave-synchronized shock (> 20 J, without inducing VF). The test was performed under sedation with Midazolam. RESULTS Twelve patients (80%) had a normal behavior during shock testing: In 8 cases induced VF was correctly detected and treated; in 4 cases of R-wave-synchronized shock electrical parameters remained stable and normal. Three patients (20%) failed the test. One patient with externalized conductors showed a sudden drop of high-voltage impedance (< 10 Ohm) after a 25 J R-wave-synchronized shock. Two other patients with externalized conductors, undergoing defibrillation testing, showed a short-circuit during shock delivery and the implantable cardioverter defibrillator was unable to interrupt VF. CONCLUSION In Riata™ leads the delivery of a low current during routine measurement of high-voltage impedance may not reveal a small short circuit, that can only be evident by attempting to deliver a true shock, either for spontaneous arrhythmias or in the context of a shock testing. PMID:27957252

  11. Experience With the Wearable Cardioverter-Defibrillator in Patients at High Risk for Sudden Cardiac Death

    PubMed Central

    Günther, Michael; Quick, Silvio; Pfluecke, Christian; Rottstädt, Fabian; Szymkiewicz, Steven J.; Ringquist, Steven; Strasser, Ruth H.; Speiser, Uwe

    2016-01-01

    Background: This study evaluated the wearable cardioverter-defibrillator (WCD) for use and effectiveness in preventing sudden death caused by ventricular tachyarrhythmia or fibrillation. Methods: From April 2010 through October 2013, 6043 German WCD patients (median age, 57 years; male, 78.5%) were recruited from 404 German centers. Deidentified German patient data were used for a retrospective, nonrandomized analysis. Results: Ninety-four patients (1.6%) were treated by the WCD in response to ventricular tachyarrhythmia/fibrillation. The incidence rate was 8.4 (95% confidence interval, 6.8–10.2) per 100 patient-years. Patients with implantable cardioverter-defibrillator explantation had an incidence rate of 19.3 (95% confidence interval, 12.2–29.0) per 100 patient-years. In contrast, an incidence rate of 8.2 (95% confidence interval, 6.4–10.3) was observed in the remaining cardiac diagnosis groups, including dilated cardiomyopathy, myocarditis, and ischemic and nonischemic cardiomyopathies. Among 120 shocked patients, 112 (93%) survived 24 hours after treatment, whereas asystole was observed in 2 patients (0.03%) with 1 resulting death. ConclusionS: This large cohort represents the first nationwide evaluation of WCD use in patients outside the US healthcare system and confirms the overall value of the WCD in German treatment pathways. PMID:27458236

  12. Role of the lead structure in MRI-induced heating: In vitro measurements on 30 commercial pacemaker/defibrillator leads.

    PubMed

    Mattei, Eugenio; Calcagnini, Giovanni; Censi, Federica; Triventi, Michele; Bartolini, Pietro

    2012-04-01

    MRI-induced heating on endocardial leads is a serious concern for the safety of patients with implantable pacemakers or cardioverter-defibrillator. The lead heating depends on many factors and its amount is largely variable. In this study, we investigated the role of those structural properties of the lead that are reported on the accompanying documents of the device: (1) fixation modality (active vs. passive); (2) number of electrodes (unipolar vs. bipolar); (3) length; (4) tip surface; and (5) tip and ring resistance. In vitro temperature and specific absorption rate measurements on 30 leads (27 pacemakers, three implantable cardioverter-defibrillator leads) exposed to the radiofrequency field typical of a 1.5 T MRI scanner are presented. The data show that each lead has its own attitude to radiofrequency-induced heating and that the information that is available in the accompanying documents of the pacemaker is not sufficient to explain such attitude. Even if combined with that of the implant geometry, this information is still not sufficient to estimate the amount of heating due to the exposure to the radiofrequency field during MRI examination.

  13. Combined use of non-thoracotomy cardioverter defibrillators and endocardial pacemakers.

    PubMed Central

    Noguera, H. H.; Peralta, A. O.; John, R. M.; Venditti, F. J.; Martin, D. T.

    1997-01-01

    OBJECTIVE: To study the potential interactions in patients with endocardial permanent pacemakers and non-thoracotomy implantable cardioverter defibrillator (ICD) systems. DESIGN: Case series and cohort study. SETTING: Tertiary referral centre. PATIENTS: Fifteen consecutive patients with both endocardial pacemakers (12 dual chamber and three single chamber) and non-thoracotomy ICD systems. MAIN OUTCOME MEASURES: Detection inhibition of induced ventricular fibrillation; double counting; and pacemaker function after shocks. In the evaluation of detection inhibition, 124 VF inductions were analysed for detection duration compared with induced VF episodes in controls with an ICD but without a pacemaker. RESULTS: Two patients (13%) showed detection inhibition of VF and required pacemaker system change at the time of the ICD implant. With the final lead position, despite frequent pacemaker undersensing of VF, ICD detection of VF was not inhibited during any induction, and neither initial detection nor redetection times for VF were different from controls. Double/triple counting of pacemaker artefact and evoked electrogram was noted in three patients (20%). In two, this was remedied during the implantation procedure, and in the other it was abolished when amiodarone treatment was discontinued. Pacemaker function was affected by ICD discharges in two patients, one who showed postshock atrial undersensing and loss of capture, and another whose pacemaker reverted to VVI mode. CONCLUSIONS: When careful testing is performed at implantation to detect and remedy device interactions, non-thoracotomy ICD treatment and endocardial pacemakers can be used safely in combination. Images PMID:9290402

  14. Long-term outcome of defibrillator recipients included in the federal audit conducted by the Department of Justice.

    PubMed

    Shariff, Nasir; Rahim, Shiraz; Jain, Sandeep; Barrington, William; Saba, Samir

    2014-09-01

    Institutions across the United States have been subjected to a federal audit for defibrillator implantable cardioverter defibrillator [ICD] implantations that violated the Centers for Medicare and Medicaid payment policy. We examined the long-term outcome of ICD recipients whose implantation procedures were audited by the Department of Justice (DOJ). Patients (n = 225) included in the DOJ audit at the University of Pittsburgh Medical Center between the years 2003 and 2010 were followed to the end point of all-cause mortality. A cohort of 206 consecutive and contemporary ICD recipients not included in the federal audit served as controls. Compared with the controls, the audited cases were older (p <0.001), had more preserved ejection fraction (p <0.001), and were less likely to be implanted for a primary prevention indication (p = 0.001). They also had significantly shorter time from myocardial infarction (p <0.001) or revascularization (p <0.001) to ICD implantation. Over a median follow-up of 3.6 years, 187 patients died and 71 received ICD therapy for ventricular arrhythmias. Patients whose cases were audited had worse survival compared with controls (hazard ratio 1.41, 95% confidence interval 1.05 to 1.90, p = 0.023) even after correcting for differences in baseline characteristics (hazard ratio 1.46, 95% confidence interval 1.05 to 2.02, p = 0.023). Rates of appropriate and inappropriate ICD therapies were similar between the audited cases and controls. In conclusion, patients whose ICD implantations were audited by the DOJ have worse long-term survival compared with nonaudited control patients. These data support compliance with the Centers for Medicare and Medicaid guidelines when the individual patient's clinical condition allows it.

  15. Public health surveillance of automated external defibrillators in the USA: protocol for the dynamic automated external defibrillator registry study

    PubMed Central

    Elrod, JoAnn Broeckel; Merchant, Raina; Daya, Mohamud; Youngquist, Scott; Salcido, David; Valenzuela, Terence; Nichol, Graham

    2017-01-01

    Introduction Lay use of automated external defibrillators (AEDs) before the arrival of emergency medical services (EMS) providers on scene increases survival after out-of-hospital cardiac arrest (OHCA). AEDs have been placed in public locations may be not ready for use when needed. We describe a protocol for AED surveillance that tracks these devices through time and space to improve public health, and survival as well as facilitate research. Methods and analysis Included AEDs are installed in public locations for use by laypersons to treat patients with OHCA before the arrival of EMS providers on scene. Included cases of OHCA are patients evaluated by organised EMS personnel and treated for OHCA. Enrolment of 10 000 AEDs annually will yield precision of 0.4% in the estimate of readiness for use. Enrolment of 2500 patients annually will yield precision of 1.9% in the estimate of survival to hospital discharge. Recruitment began on 21 Mar 2014 and is ongoing. AEDs are found by using multiple methods. Each AED is then tagged with a label which is a unique two-dimensional (2D) matrix code; the 2D matrix code is recorded and the location and status of the AED tracked using a smartphone; these elements are automatically passed via the internet to a secure and confidential database in real time. Whenever the 2D matrix code is rescanned for any non-clinical or clinical use of an AED, the user is queried to answer a finite set of questions about the device status. The primary outcome of any clinical use of an AED is survival to hospital discharge. Results are summarised descriptively. Ethics and dissemination These activities are conducted under a grant of authority for public health surveillance from the Food and Drug Administration. Results are provided periodically to participating sites and sponsors to improve public health and quality of care. PMID:28360255

  16. Automated external defibrillators and sudden cardiac arrest.

    PubMed

    Sachs, R G; Kerwin, J

    2001-04-01

    In April 1998, R.R., aged 72 (a man with no prior history of cardiac disease), was leaving his house with two friends to play golf when he suddenly collapsed. One friend initiated CPR, and the other called 911 on his cellular phone. A Chatham police squad arrived within three minutes; the police "first responder" applied a portable automated external defibrillator (AED) to the unresponsive patient. The AED instructed the first responder to push the shock button. Pulse and blood pressure were immediately restored, and the patient was brought to the Overlook Hospital Emergency Room. The patient subsequently awakened, had a cardiac catheterization revealing severe three-vessel coronary artery disease, and then underwent successful coronary artery bypass surgery. Two and a half years later he remained asymptomatic and was seen in the office of his cardiologist for a routine semiannual exam. Later that same day he was scheduled to play golf with the same two friends who had previously saved his life.

  17. Damage in canine hearts following defibrillator shocks.

    PubMed

    Lumb, G; Anderson, G J; Kase, M L; Woo, D V

    1986-01-01

    Experiments were performed to investigate possible differences in potential myocardial cell damage following the use of two clinically available difibrillators. One had a damped sine wave (DSW), and the other a truncated exponential waveform (TEW). The latter, therefore, had a lower peak current and voltage. After pilot studies to determine damage potential, an energy content of 10 Joules per kg was selected with three transthoracic shocks at 30 second intervals, delivered with paddles, by both defibrillators. Thirteen dogs were shocked with DSW (10 sacrificed at 24 hours and three at 72 hours). Eleven dogs were shocked with TEW (eight sacrificed at 24 hours and three at 72 hours). Three were used as untreated controls. Observations included ECG monitoring, technetium99m pyrophosphate (Tc-PyP) uptake, and gross and microscopic observations including electron microscopy. This report will concentrate on the morphologic changes. Eleven of 13 dogs shocked with DSW developed ventricular tachycardia, transient heart block, Tc-PyP uptake and myocardial cell death with acute necrosis, and aberrant contraction patterns associated with cell death. Progression of the lesions occurred from 24 to 72 hours. Only two (one at 24 hours and one at 72 hours) of the dogs shocked with TEW showed microscopic foci of necrosis. One was a chance finding (24 hours); the other was associated with an overlying "yellow streak". In neither case were arrhythmias or Tc-PyP uptake observed. The results indicate that in dogs at equivalent energy levels, TEW caused significantly less myocardial damage than DSW.

  18. Externalized conductors and insulation failure in Biotronik defibrillator leads: History repeating or a false alarm?

    PubMed

    De Maria, Elia; Borghi, Ambra; Bonetti, Lorenzo; Fontana, Pier Luigi; Cappelli, Stefano

    2017-02-16

    Conductor externalization and insulation failure are frequent complications with the recalled St. Jude Medical Riata implantable cardioverter-defibrillator (ICD) leads. Conductor externalization is a "unique" failure mechanism: Cables externalize through the insulation ("inside-out" abrasion) and appear outside the lead body. Recently, single reports described a similar failure also for Biotronik leads. Moreover, some studies reported a high rate of electrical dysfunction (not only insulation failure) with Biotronik Linox leads and a reduced survival rate in comparison with the competitors. In this paper we describe the case of a patient with a Biotronik Kentrox ICD lead presenting with signs of insulation failure and conductor externalization at fluoroscopy. Due to the high risk of extraction we decided to implant a new lead, abandoning the damaged one; lead reimplant was uneventful. Subsequently, we review currently available literature about Biotronik Kentrox and Linox ICD lead failure and in particular externalized conductors. Some single-center studies and a non-prospective registry reported a survival rate between 88% and 91% at 5 years for Linox leads, significantly worse than that of other manufacturers. However, the preliminary results of two ongoing multicenter, prospective registries (GALAXY and CELESTIAL) showed 96% survival rate at 5 years after implant, well within industry standards. Ongoing data collection is needed to confirm longer-term performance of this family of ICD leads.

  19. Externalized conductors and insulation failure in Biotronik defibrillator leads: History repeating or a false alarm?

    PubMed Central

    De Maria, Elia; Borghi, Ambra; Bonetti, Lorenzo; Fontana, Pier Luigi; Cappelli, Stefano

    2017-01-01

    Conductor externalization and insulation failure are frequent complications with the recalled St. Jude Medical Riata implantable cardioverter-defibrillator (ICD) leads. Conductor externalization is a “unique” failure mechanism: Cables externalize through the insulation (“inside-out” abrasion) and appear outside the lead body. Recently, single reports described a similar failure also for Biotronik leads. Moreover, some studies reported a high rate of electrical dysfunction (not only insulation failure) with Biotronik Linox leads and a reduced survival rate in comparison with the competitors. In this paper we describe the case of a patient with a Biotronik Kentrox ICD lead presenting with signs of insulation failure and conductor externalization at fluoroscopy. Due to the high risk of extraction we decided to implant a new lead, abandoning the damaged one; lead reimplant was uneventful. Subsequently, we review currently available literature about Biotronik Kentrox and Linox ICD lead failure and in particular externalized conductors. Some single-center studies and a non-prospective registry reported a survival rate between 88% and 91% at 5 years for Linox leads, significantly worse than that of other manufacturers. However, the preliminary results of two ongoing multicenter, prospective registries (GALAXY and CELESTIAL) showed 96% survival rate at 5 years after implant, well within industry standards. Ongoing data collection is needed to confirm longer-term performance of this family of ICD leads. PMID:28255544

  20. Low Energy Multi-Stage Atrial Defibrillation Therapy Terminates Atrial Fibrillation with Less Energy than a Single Shock

    PubMed Central

    Li, Wenwen; Janardhan, Ajit H.; Fedorov, Vadim V.; Sha, Qun; Schuessler, Richard B.; Efimov, Igor R.

    2011-01-01

    Background Implantable device therapy of atrial fibrillation (AF) is limited by pain from high-energy shocks. We developed a low-energy multi-stage defibrillation therapy and tested it in a canine model of AF. Methods and Results AF was induced by burst pacing during vagus nerve stimulation. Our novel defibrillation therapy consisted of three stages: ST1 (1-4 low energy biphasic shocks), ST2 (6-10 ultra-low energy monophasic shocks), and ST3 (anti-tachycardia pacing). Firstly, ST1 testing compared single or multiple monophasic (MP) and biphasic (BP) shocks. Secondly, several multi-stage therapies were tested: ST1 versus ST1+ST3 versus ST1+ST2+ST3. Thirdly, three shock vectors were compared: superior vena cava to distal coronary sinus (SVC>CSd), proximal coronary sinus to left atrial appendage (CSp>LAA) and right atrial appendage to left atrial appendage (RAA>LAA). The atrial defibrillation threshold (DFT) of 1BP shock was less than 1MP shock (0.55 ± 0.1 versus 1.38 ± 0.31 J; p =0.003). 2-3 BP shocks terminated AF with lower peak voltage than 1BP or 1MP shock and with lower atrial DFT than 4 BP shocks. Compared to ST1 therapy alone, ST1+ST3 lowered the atrial DFT moderately (0.51 ± 0.46 versus 0.95 ± 0.32 J; p = 0.036) while a three-stage therapy, ST1+ST2+ST3, dramatically lowered the atrial DFT (0.19 ± 0.12 J versus 0.95 ± 0.32 J for ST1 alone, p=0.0012). Finally, the three-stage therapy ST1+ST2+ST3 was equally effective for all studied vectors. Conclusions Three-stage electrotherapy significantly reduces the AF defibrillation threshold and opens the door to low energy atrial defibrillation at or below the pain threshold. PMID:21980076

  1. A biophysical model for defibrillation of cardiac tissue.

    PubMed Central

    Keener, J P; Panfilov, A V

    1996-01-01

    We propose a new model for electrical activity of cardiac tissue that incorporates the effects of cellular microstructure. As such, this model provides insight into the mechanism of direct stimulation and defibrillation of cardiac tissue after injection of large currents. To illustrate the usefulness of the model, numerical stimulations are used to show the difference between successful and unsuccessful defibrillation of large pieces of tissue. Images FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 FIGURE 9 PMID:8874007

  2. Marketing defibrillation training programs and bystander intervention support.

    PubMed

    Sneath, Julie Z; Lacey, Russell

    2009-01-01

    This exploratory study identifies perceptions of and participation in resuscitation training programs, and bystanders' willingness to resuscitate cardiac arrest victims. While most of the study's participants greatly appreciate the importance of saving someone's life, many indicated that they did not feel comfortable assuming this role. The findings also demonstrate there is a relationship between type of victim and bystanders' willingness to intervene. Yet, bystander intervention discomfort can be overcome with cardiopulmonary resuscitation and defibrillation training, particularly when the victim is a coworker or stranger. Further implications of these findings are discussed and modifications to public access defibrillation (PAD) training programs' strategy and communications are proposed.

  3. 21 CFR 870.5310 - Automated external defibrillator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 870.5310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... shock of a maximum of 360 joules of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart. An AED analyzes the patient's electrocardiogram, interprets...

  4. Advantage of four-electrode over two-electrode defibrillators

    NASA Astrophysics Data System (ADS)

    Bragard, J.; Šimić, A.; Laroze, D.; Elorza, J.

    2015-12-01

    Defibrillation is the standard clinical treatment used to stop ventricular fibrillation. An electrical device delivers a controlled amount of electrical energy via a pair of electrodes in order to reestablish a normal heart rate. We propose a technique that is a combination of biphasic shocks applied with a four-electrode system rather than the standard two-electrode system. We use a numerical model of a one-dimensional ring of cardiac tissue in order to test and evaluate the benefit of this technique. We compare three different shock protocols, namely a monophasic and two types of biphasic shocks. The results obtained by using a four-electrode system are compared quantitatively with those obtained with the standard two-electrode system. We find that a huge reduction in defibrillation threshold is achieved with the four-electrode system. For the most efficient protocol (asymmetric biphasic), we obtain a reduction in excess of 80% in the energy required for a defibrillation success rate of 90%. The mechanisms of successful defibrillation are also analyzed. This reveals that the advantage of asymmetric biphasic shocks with four electrodes lies in the duration of the cathodal and anodal phase of the shock.

  5. Possibilities for predictive measurement of the transthoracic impedance in defibrillation.

    PubMed

    Krasteva, V; Hatib, F A; Trendafilova, E; Daskalov, I

    2001-01-01

    Transthoracic electrical defibrillation is administered by high voltages and currents applied through large size electrodes. Therefore, the defibrillator load impedance becomes an essential factorfor the efficacy of the procedure. Attempts at prediction of transthoracic impedance by pre-shock measurement with low-amplitude high-frequency current have yielded apparently promising results. A reassessment was undertaken of the comparison between transthoracic impedance measured over a wide frequency range (bioimpedance spectroscopy) and measured during the shock. An estimation of the possibilities for pre-shock 'prediction ' of the impedance was performed, to allow adequate selection of the defibrillation energy or current with the intention of increasing the possibility for positive results with the first shock. Data were obtained from experimental fibrillation/defibrillation cycles on dogs andfrom cardioversion of atrial fibrillation or flutter in patients. The final results suggest that high-frequency low-amplitude impedance measurements cannot predict the corresponding value during the shock with very high accuracy, as differences up to 15-17% were found using biphasic pulses in patients. However, the method can be used for approximate assessments.

  6. Assessment of balanced biphasic defibrillation waveforms in transthoracic atrial cardioversion.

    PubMed

    Krasteva, V; Trendafilova, E; Cansell, A; Daskalov, I

    2001-01-01

    Various electrical pulses have been used for defibrillation. The monophasic damped sinusoid waveform, initiated in 60 s, was adopted in virtually all defibrillators. Biphasic pulses were introduced recently, achieving success with less energy. A biphasic exponential waveform was modelled with 4 ms duration per phase with a balanced 3:1 ratio of the first to second phase peak voltages and implemented in a defibrillator. A version obtained by chopping the pulses with a 5 kHz frequency was also used. It was hypothesized that the modelled transmembrane voltage decay time is a parameter that could be associated with successful defibrillation. The results of cardioversion for two groups of patients with the 'classic' monophasic waveform and with the biphasic pulses were compared. The mean efficient energy with the damped sinusoid was 205 +/- 85 J, versus 88 +/- 43 J with the biphasic pulses, yielding a ratio of 2.32 (1.92 to 3.2 for fibrillation and flutter, respectively). An acceptable agreement between model data and clinical results was found. The transmembrane voltage decay time ratios for monophasic versus biphasic pulses was in the approximate range of 2.5 to 3.5.

  7. An unusual etiological agent of implantable cardioverter device endocarditis: Corynebacterium mucifaciens

    PubMed Central

    Kaya, Adnan; Tekkesin, Ahmet Ilker; Kalenderoglu, Koray; Alper, Ahmet Taha

    2016-01-01

    Cardiac pacing devices and implantable cardioverter defibrillator (ICD) are becoming the mainstay of therapy in cardiology and infective endocarditis (IE) and pocket infection; however, these devices require careful monitoring. Here, we describe a case of a 68-year-old female with an ICD presenting with a previously unknown etiological agent of IE, Corynebacterium mucifaciens. PMID:27133333

  8. Cardiac chambers perforation by pacemaker and cardioverter-defibrillator leads. Own experience in diagnosis, treatment and preventive methods.

    PubMed

    Maziarz, Andrzej; Ząbek, Andrzej; Małecka, Barbara; Kutarski, Andrzej; Lelakowski, Jacek

    2012-01-01

    Cardiac chamber perforation is an uncommon, but potentially dangerous, complication of implantation of a pacemaker (PM) or a cardioverter-defibrillator (ICD). Different clinical presentations are related to the time between implantation and perforation, localisation of the perforation and concomitant lesions in neighbouring organs. Diagnosis is based on concomitant analysis of the clinical picture, ECG tracings, PM or ICD function check-up with a programmer, and review of echocardiographic, X-ray and computed tomography pictures. We analysed seven cases of perforation. Perforating leads were removed in all cases and a new pacing system was implanted in five cases. Choice of operative technique (unscrewing and direct traction from device pocket, Cook system or surgical procedure with pericardial drainage) depended on the time elapsing between implantation and perforation, the presence of lesions of other organs, and the amount of fluid in the pericardial sac. Avoiding unsafe localisation of a pacing electrode in the apex and free wall of the right ventricle and in the free anterolateral wall of the right atrium, and avoiding leaving an extra length of pacing lead under tension and overscrewing of the lead helix seem to be the best ways of prevention.

  9. An ontology-based annotation of cardiac implantable electronic devices to detect therapy changes in a national registry.

    PubMed

    Rosier, Arnaud; Mabo, Philippe; Chauvin, Michel; Burgun, Anita

    2015-05-01

    The patient population benefitting from cardiac implantable electronic devices (CIEDs) is increasing. This study introduces a device annotation method that supports the consistent description of the functional attributes of cardiac devices and evaluates how this method can detect device changes from a CIED registry. We designed the Cardiac Device Ontology, an ontology of CIEDs and device functions. We annotated 146 cardiac devices with this ontology and used it to detect therapy changes with respect to atrioventricular pacing, cardiac resynchronization therapy, and defibrillation capability in a French national registry of patients with implants (STIDEFIX). We then analyzed a set of 6905 device replacements from the STIDEFIX registry. Ontology-based identification of therapy changes (upgraded, downgraded, or similar) was accurate (6905 cases) and performed better than straightforward analysis of the registry codes (F-measure 1.00 versus 0.75 to 0.97). This study demonstrates the feasibility and effectiveness of ontology-based functional annotation of devices in the cardiac domain. Such annotation allowed a better description and in-depth analysis of STIDEFIX. This method was useful for the automatic detection of therapy changes and may be reused for analyzing data from other device registries.

  10. Pediatric defibrillation after cardiac arrest: initial response and outcome

    PubMed Central

    Rodríguez-Núñez, Antonio; López-Herce, Jesús; García, Cristina; Domínguez, Pedro; Carrillo, Angel; Bellón, Jose María

    2006-01-01

    Introduction Shockable rhythms are rare in pediatric cardiac arrest and the results of defibrillation are uncertain. The objective of this study was to analyze the results of cardiopulmonary resuscitation that included defibrillation in children. Methods Forty-four out of 241 children (18.2%) who were resuscitated from inhospital or out-of-hospital cardiac arrest had been treated with manual defibrillation. Data were recorded according to the Utstein style. Outcome variables were a sustained return of spontaneous circulation (ROSC) and one-year survival. Characteristics of patients and of resuscitation were evaluated. Results Cardiac disease was the major cause of arrest in this group. Ventricular fibrillation (VF) or pulseless ventricular tachycardia (PVT) was the first documented electrocardiogram rhythm in 19 patients (43.2%). A shockable rhythm developed during resuscitation in 25 patients (56.8%). The first shock (dose, 2 J/kg) terminated VF or PVT in eight patients (18.1%). Seventeen children (38.6%) needed more than three shocks to solve VF or PVT. ROSC was achieved in 28 cases (63.6%) and it was sustained in 19 patients (43.2%). Only three patients (6.8%), however, survived at 1-year follow-up. Children with VF or PVT as the first documented rhythm had better ROSC, better initial survival and better final survival than children with subsequent VF or PVT. Children who survived were older than the finally dead patients. No significant differences in response rate were observed when first and second shocks were compared. The survival rate was higher in patients treated with a second shock dose of 2 J/kg than in those who received higher doses. Outcome was not related to the cause or the location of arrest. The survival rate was inversely related to the duration of cardiopulmonary resuscitation. Conclusion Defibrillation is necessary in 18% of children who suffer cardiac arrest. Termination of VF or PVT after the first defibrillation dose is achieved in a low

  11. Extreme externalisation of a Riata defibrillator lead conductor cable with prolapse into the left pulmonary artery.

    PubMed

    Oktay, A Afşin; Dibs, Samer R; Silver, Jeffrey M; Akbar, M Sikander

    2014-12-01

    The Riata family of defibrillator leads (St. Jude Medical, Sylmar, CA) has been recalled because of externalisation of conductor cables and increased electrical failure. We describe the case of a man with an incidental finding of extreme externalisation of a conductor from the right ventricular defibrillator lead (Riata family) with prolapse into the left pulmonary artery.

  12. Transthoracic electrical impedance during external defibrillation: comparison of measured and modelled waveforms.

    PubMed

    Al Hatib, F; Trendafilova, E; Daskalov, I

    2000-02-01

    The transthoracic electrical impedance is an important defibrillation parameter, affecting the defibrillating current amplitude and energy, and therefore the defibrillation efficiency. A close relationship between transthoracic impedance and defibrillation success rate was observed. Pre-shock measurements (using low amplitude high frequency current) of the impedance were considered a solution for selection of adequate shock voltages or for current-based defibrillation dosage. A recent approach, called 'impedance-compensating defibrillation' was implemented, where the pulse duration was controlled with respect to the impedance measured during the initial phase of the shock. These considerations raised our interest in reassessment of the transthoracic impedance characteristics and the corresponding measurement methods. The purpose of this work is to study the variations of the transthoracic impedance by a continuous measurement technique during the defibrillation shock and comparing the data with results obtained by modelling. Voltage and current impulse waveforms were acquired during cardioversion of patients with atrial fibrillation or flutter. The same type of defibrillation pulse was taken from dogs after induction of fibrillation. The electrodes were located in the anterior position, for both the patients and animals.

  13. Low-Energy Defibrillation Failure Correction is Possible Through Nonlinear Analysis of Spatiotemporal Arrhythmia Data

    NASA Astrophysics Data System (ADS)

    Simonotto, Jennifer; Furman, Michael; Beaver, Thomas; Spano, Mark; Kavanagh, Katherine; Iden, Jason; Hu, Gang; Ditto, William

    2004-03-01

    Explanted Porcine hearts were Langendorff-perfused, administered a voltage-sensitive fluorescent dye (Di-4-ANEPPS) and illuminated with a ND:Yag laser (532 nm); the change in fluorescence resulting from electrical activity on the heart surface was recorded with an 80 x 80 pixel CCD camera at 1000 frames per second. The heart was put into fibrillation with rapid ventricular pacing and shocks were administered close to the defibrillation threshold. Defibrillation failure data was analyzed using synchronization, space-time volume plots and recurrence quantification. Preliminary spatiotemporal synchronization results reveal a short window of time ( 1 second) after defibrillation failure in which the disordered electrical activity becomes ordered; this ordered period occurs 4-5 seconds after the defibrillation shock. Recurrence analysis of a single time series confirmed these results, thus opening the avenue for dynamic defibrillators that can detect an optimal window for cardioversion.

  14. Implantable diagnostic and therapeutic devices in children

    PubMed Central

    Le, T-N.; Gouw, S.C.; Hoorntje, T.M.; Sreeram, N.

    2002-01-01

    Many advances have been made in the use of implantable diagnostic and therapeutic devices in adults. In children the indications for and diagnostic and therapeutic value of these devices still have to be determined. Our aim is to provide an overview of the clinical use of diagnostic and therapeutic devices in children. The role of implantable loop recorders (ILR), the feasibility and safety of transvenous pacing in neonates, the value of permanent pacing in children with recurrent syncope or reflex anoxic seizures and the role of implantable cardioverter defibrillator devices are highlighted with relevant case histories. ImagesFigure 1a and bFigure 2aFigure 2b and 2c PMID:25696046

  15. Acute and chronic high-frequency properties of cardiac pacing and defibrillation leads.

    PubMed

    Tomasic, Danko; Ferek-Petric, Bozidar; Brusich, Sandro; Accardo, Agostino P

    2012-08-01

    The purpose of our study was to investigate variety of cardiac lead conductor designs as high-frequency (HF) transmission lines. Special attention was given on evaluation of chronic HF applications in cardiac electrotherapy. We measured the characteristic impedance and the attenuation coefficient of six pacing leads between 1 and 21 MHz. They were subsequently immersed into the saline solution simulating the body fluid and the measurements were repeated 10 years later. Identical measurements were performed on 15 new pacing and defibrillation leads. The results revealed that lead geometry is the main factor affecting the HF parameters. Attenuation coefficients of old and contemporary leads do not differ significantly. Penetration of saline within the leads during a decade did not influence much their HF characteristics. Thus, a chronic cardiac contraction sensor based on lead's HF impedance variation is feasible. The signal losses of ultrasonic transducers mounted on the lead might be stable for years at acceptable levels without significant variation. Due to mutually similar values of HF parameters in different leads, design of tensiometric or ultrasonic applications could be universal for majority of commercially available leads. Automatic system calibration could be developed for each and every lead after determination of its HF parameters.

  16. Automatic Imitation

    ERIC Educational Resources Information Center

    Heyes, Cecilia

    2011-01-01

    "Automatic imitation" is a type of stimulus-response compatibility effect in which the topographical features of task-irrelevant action stimuli facilitate similar, and interfere with dissimilar, responses. This article reviews behavioral, neurophysiological, and neuroimaging research on automatic imitation, asking in what sense it is "automatic"…

  17. Perioperative management of patients with cardiac implantable electronic devices.

    PubMed

    Poveda-Jaramillo, R; Castro-Arias, H D; Vallejo-Zarate, C; Ramos-Hurtado, L F

    2017-05-01

    The use of implantable cardiac devices in people of all ages is increasing, especially in the elderly population: patients with pacemakers, cardioverter-defibrillators or cardiac resynchronization therapy devices regularly present for surgery for non-cardiac causes. This review was made in order to collect and analyze the latest evidence for the proper management of implantable cardiac devices in the perioperative period. Through a detailed exploration of PubMed, Academic Search Complete (EBSCO), ClinicalKey, Cochrane (Ovid), the search software UpToDate, textbooks and patents freely available to the public on Google, we selected 33 monographs, which matched the objectives of this publication.

  18. Capacity of dental equipment to interfere with cardiac implantable electrical devices.

    PubMed

    Lahor-Soler, Eduard; Miranda-Rius, Jaume; Brunet-Llobet, Lluís; Sabaté de la Cruz, Xavier

    2015-06-01

    Patients with cardiac implantable electrical devices should take precautions when exposed to electromagnetic fields. Possible interference as a result of proximity to electromagnets or electricity flow from electronic tools employed in clinical odontology remains controversial. The objective of this study was to examine in vitro the capacity of dental equipment to provoke electromagnetic interference in pacemakers and implantable cardioverter defibrillators. Six electronic dental instruments were tested on three implantable cardioverter defibrillators and three pacemakers from different manufacturers. A simulator model, submerged in physiological saline, with elements that reproduced life-size anatomic structures was used. The instruments were analyzed at differing distances and for different time periods of application. The dental instruments studied displayed significant differences in their capacity to trigger electromagnetic interference. Significant differences in the quantity of registered interference were observed with respect to the variables manufacturer, type of cardiac implant, and application distance but not with the variable time of application. The electronic dental equipment tested at a clinical application distance (20 cm) provoked only slight interference in the pacemakers and implantable cardioverter defibrillators employed, irrespective of manufacturer.

  19. Safety of magnetic resonance imaging in patients with implanted cardiac prostheses and metallic cardiovascular electronic devices.

    PubMed

    Baikoussis, Nikolaos G; Apostolakis, Efstratios; Papakonstantinou, Nikolaos A; Sarantitis, Ioannis; Dougenis, Dimitrios

    2011-06-01

    Magnetic resonance imaging (MRI) in patients with implanted cardiac prostheses and metallic cardiovascular electronic devices is sometimes a risky procedure. Thus MRI in these patients should be performed when it is the only examination able to help with the diagnosis. Moreover the diagnostic benefit must outweigh the risks. Coronary artery stents, prosthetic cardiac valves, metal sternal sutures, mediastinal vascular clips, and epicardial pacing wires are not contraindications for MRI, in contrast to pacemakers and implantable cardioverter-defibrillators. Appropriate patient selection and precautions ensure MRI safety. However it is commonly accepted that although hundreds of patients with pacemakers or implantable cardioverter-defibrillators have undergone safe MRI scanning, it is not a safe procedure. Currently, heating of the pacemaker lead is the major problem undermining MRI safety. According to the US Food and Drug Administration (FDA), there are currently neither "MRI-safe" nor "MRI-compatible" pacemakers and implantable cardioverter-defibrillators. In this article we review the international literature in regard to safety during MRI of patients with implanted cardiac prostheses and metallic cardiovascular electronic devices.

  20. Comparison of ease of use of three automated external defibrillators by untrained lay people.

    PubMed

    Eames, P; Larsen, P D; Galletly, D C

    2003-07-01

    The use of automated external defibrillators (AED) by lay people has the potential to markedly increase survival from community cardiac arrest. Wider public use of AEDs requires units that can be operated safely and effectively by people with minimal or no training. This study compares the use of three AEDs by untrained lay people regarding ease-of-use, safety, pad positioning and time to defibrillation. 24 subjects with no prior exposure to the use of AEDs were asked to perform simulated defibrillation on a manikin using three defibrillators: Zoll AEDPlus, Medtronic Physio-Control LifePak CR Plus and Philips/Laerdal HeartStart OnSite Defibrillator. Subjects' performance were videotaped and reviewed for time to defibrillate, pad positioning and safety. Subjects were asked to rate the three units in terms of ease-of-use. Average times to first shock were 74.8 s for the Physio-Control, 83.0 s for the Laerdal and 153.4 s for the Zoll defibrillator. Pad positioning was scored as correct in 23/24 Laerdal trials, 19/24 Physio-Control trials and 14/24 Zoll trials. 23 out of the 24 subjects rated the Zoll most difficult to use. All subjects safely stayed clear of the unit when required. The majority of subjects safely and effectively delivered defibrillating shocks without any prior training and within quite acceptable times. Untrained subjects find the Physio-Control and Laerdal Defibrillator easier to use than the Zoll device. Features of AED design that improved ease of use are discussed.

  1. Automated external defibrillators in the Australian fitness industry.

    PubMed

    Norton, Kevin I; Norton, Lynda H

    2008-04-01

    Sudden cardiac arrest (SCA) occurs in many thousands of Australians each year. Scientific evidence shows an increased survival rate for individuals who receive electrical defibrillation in the first few minutes after SCA. In the last decade automated (rhythm-detecting) external defibrillators (AEDs) have become available that are portable and affordable. Although still relatively rare, there is still the potential that SCA may occur when a person undertakes physical activity. Consequently, health/fitness centres are increasingly recognised as higher risk sites that may benefit from placement of AEDs. There are no laws in Australia requiring health/fitness centres to install AEDs. However, several international and professional organisations have "strongly encouraged" larger centres to install AEDs. Guidelines and algorithms are presented to help estimate the risk of SCA in fitness centres. Fitness centre placement is particularly important if the clientele is older or has a 'high-risk' profile, for example, clients with cardiovascular, respiratory or metabolic disease. International negligence case law and duty of care principles suggests the standard of care required in health/fitness centres may be increasing. Therefore, it may be prudent to install AEDs in larger centres and those in which higher risk groups are physically active.

  2. Cochlear Implants.

    ERIC Educational Resources Information Center

    Clark, Catherine; Scott, Larry

    This brochure explains what a cochlear implant is, lists the types of individuals with deafness who may be helped by a cochlear implant, describes the process of evaluating people for cochlear implants, discusses the surgical process for implanting the aid, traces the path of sound through the cochlear implant to the brain, notes the costs of…

  3. Are patients with cardiac implants protected against electromagnetic interference in daily life and occupational environment?

    PubMed

    Napp, Andreas; Stunder, Dominik; Maytin, Melanie; Kraus, Thomas; Marx, Nikolaus; Driessen, Sarah

    2015-07-21

    Utilization of cardiac implants such as pacemakers and implantable cardioverter defibrillators is now commonplace among heart disease patients. The ever-increasing technological complexity of these devices is matched by the near omnipresent exposure to electric, magnetic, and electromagnetic fields (EMFs), both in everyday life and the occupational environment. Given that electromagnetic interferences (EMIs) are associated with potential risk in device patients, physicians are increasingly confronted with managing device patients with intermittent EMI and chronic occupational exposure. The current review aims to provide a contemporary overview of cardiovascular implantable electronic devices, their function and susceptibility of non-medical EMFs and provide recommendations for physicians caring for cardiac device patients presenting with EMI.

  4. Management of Patients With Cardiovascular Implantable Electronic Devices in Dental, Oral, and Maxillofacial Surgery

    PubMed Central

    Tom, James

    2016-01-01

    The prevalence of cardiovascular implantable electronic devices as life-prolonging and life-saving devices has evolved from a treatment of last resort to a first-line therapy for an increasing number of patients. As these devices become more and more popular in the general population, dental providers utilizing instruments and medications should be aware of dental equipment and medications that may affect these devices and understand the management of patients with these devices. This review article will discuss the various types and indications for pacemakers and implantable cardioverter-defibrillators, common drugs and instruments affecting these devices, and management of patients with these devices implanted for cardiac dysrhythmias. PMID:27269668

  5. Management of Patients With Cardiovascular Implantable Electronic Devices in Dental, Oral, and Maxillofacial Surgery.

    PubMed

    Tom, James

    2016-01-01

    The prevalence of cardiovascular implantable electronic devices as life-prolonging and life-saving devices has evolved from a treatment of last resort to a first-line therapy for an increasing number of patients. As these devices become more and more popular in the general population, dental providers utilizing instruments and medications should be aware of dental equipment and medications that may affect these devices and understand the management of patients with these devices. This review article will discuss the various types and indications for pacemakers and implantable cardioverter-defibrillators, common drugs and instruments affecting these devices, and management of patients with these devices implanted for cardiac dysrhythmias.

  6. Risk of electromagnetic interference induced by dental equipment on cardiac implantable electrical devices.

    PubMed

    Miranda-Rius, Jaume; Lahor-Soler, Eduard; Brunet-Llobet, Lluís; Sabaté de la Cruz, Xavier

    2016-12-01

    Patients with cardiac implantable electrical devices should take special precautions when exposed to electromagnetic fields. Proximity to equipment used in clinical dentistry may cause interference. This study evaluated in vitro the risks associated with different types/makes of cardiac devices and types of dental equipment. Six electronic dental tools were tested on three implantable cardioverter defibrillators and three pacemakers made by different manufacturers. Overall, the risk of interference with the pacemakers was 37% lower than with the implantable cardioverter defibrillators. Regarding the types/makes of cardiac devices analysed, that from Boston Scientific had a five-fold greater risk of interference than did that from Biotronik [prevalence ratio (PR) = 5.58]; there was no difference between that from Biotronik and that from Medtronic. Among the dental equipment, the electric pulp tester had the greatest risk of inducing interference and therefore this device was used as the benchmark. The electronic apex locator (PR = 0.29), Periotest M (PR = 0.47), and the ultrasonic dental scaler (PR = 0.59) were less likely to induce interference than the electric pulp tester. The risk was lowest with the electronic apex locator. Pacemakers presented a lower risk of light to moderate interference (PR = 0.63). However, the risk of severe electromagnetic interference was 3.5 times higher with pacemakers than with implantable cardioverter defibrillators (PR = 3.47).

  7. Optimizing a Drone Network to Deliver Automated External Defibrillators.

    PubMed

    Boutilier, Justin J; Brooks, Steven C; Janmohamed, Alyf; Byers, Adam; Buick, Jason E; Zhan, Cathy; Schoellig, Angela P; Cheskes, Sheldon; Morrison, Laurie J; Chan, Timothy C Y

    2017-03-02

    Background -Public access defibrillation programs can improve survival after out-of-hospital cardiac arrest (OHCA), but automated external defibrillators (AEDs) are rarely available for bystander use at the scene. Drones are an emerging technology that can deliver an AED to the scene of an OHCA for bystander use. We hypothesize that a drone network designed with the aid of a mathematical model combining both optimization and queuing can reduce the time to AED arrival. Methods -We applied our model to 53,702 OHCAs that occurred in the eight regions of the Toronto Regional RescuNET between January 1st 2006 and December 31st 2014. Our primary analysis quantified the drone network size required to deliver an AED one, two, or three minutes faster than historical median 911 response times for each region independently. A secondary analysis quantified the reduction in drone resources required if RescuNET was treated as one large coordinated region. Results -The region-specific analysis determined that 81 bases and 100 drones would be required to deliver an AED ahead of median 911 response times by three minutes. In the most urban region, the 90th percentile of the AED arrival time was reduced by 6 minutes and 43 seconds relative to historical 911 response times in the region. In the most rural region, the 90th percentile was reduced by 10 minutes and 34 seconds. A single coordinated drone network across all regions required 39.5% fewer bases and 30.0% fewer drones to achieve similar AED delivery times. Conclusions -An optimized drone network designed with the aid of a novel mathematical model can substantially reduce the AED delivery time to an OHCA event.

  8. Cardiovascular implantable electronic devices: patient education, information and ethical issues.

    PubMed

    Manaouil, Cécile; Gignon, Maxime; Traulle, Sarah

    2012-09-01

    Cardiovascular implantable electronic devices (CIED) are implanted increasingly frequently. CIEDs are indicated for the treatment of bradycardia, tachycardia and heart failure and therefore improve quality of life and life expectancy. CIED can treat ventricular arrhythmias that would be fatal without immediate care. However, CIEDs raise several patient education, medico-legal, and ethical questions that will be addressed in this article. Information is a patient's right, and necessary for informed consent. When implanting a CIED, the patient must be educated about the need for the device, the function of the device, any restrictions that apply postimplant, and postimplant follow-up methods and schedules. This transfer of information to the patient makes the patient responsible. The occupational physician can determine whether a patient wearing a CIED is able to work. Under current French law, patients are not prohibited from working while wearing a CIED. However, access to certain job categories remains limited, such as jobs involving mechanical stress to the chest, exposure to electromagnetic fields, or jobs requiring permanent vigilance. Pacemakers and defibrillators are medical treatments and are subject to the same ethical and clinical considerations as any other treatment. However, stopping a pacemaker or a defibrillator raises different ethical issues. Implantable Cardioverter Defibrillator shocks can be considered to be equivalent to resuscitation efforts and can be interpreted as being unreasonable in an end-of-life patient. Pacing is painless and it is unlikely to unnecessarily prolong the life of a patient with a terminal disease. Patients with a CIED should live as normally as possible, but must also be informed about the constraints related to the device and must inform each caregiver about the presence of the device. The forensic and ethical implications must be assessed in relation to current legislation.

  9. The cardiac implantable electronic device power source: evolution and revolution.

    PubMed

    Mond, Harry G; Freitag, Gary

    2014-12-01

    Although the first power source for an implantable pacemaker was a rechargeable nickel-cadmium battery, it was rapidly replaced by an unreliable short-life zinc-mercury cell. This sustained the small pacemaker industry until the early 1970s, when the lithium-iodine cell became the dominant power source for low voltage, microampere current, single- and dual-chamber pacemakers. By the early 2000s, a number of significant advances were occurring with pacemaker technology which necessitated that the power source should now provide milliampere current for data logging, telemetric communication, and programming, as well as powering more complicated pacing devices such as biventricular pacemakers, treatment or prevention of atrial tachyarrhythmias, and the integration of innovative physiologic sensors. Because the current delivery of the lithium-iodine battery was inadequate for these functions, other lithium anode chemistries that can provide medium power were introduced. These include lithium-carbon monofluoride, lithium-manganese dioxide, and lithium-silver vanadium oxide/carbon mono-fluoride hybrids. In the early 1980s, the first implantable defibrillators for high voltage therapy used a lithium-vanadium pentoxide battery. With the introduction of the implantable cardioverter defibrillator, the reliable lithium-silver vanadium oxide became the power source. More recently, because of the demands of biventricular pacing, data logging, and telemetry, lithium-manganese dioxide and the hybrid lithium-silver vanadium oxide/carbon mono-fluoride laminate have also been used. Today all cardiac implantable electronic devices are powered by lithium anode batteries.

  10. Automatic transmission

    SciTech Connect

    Miura, M.; Aoki, H.

    1988-02-02

    An automatic transmission is described comprising: an automatic transmission mechanism portion comprising a single planetary gear unit and a dual planetary gear unit; carriers of both of the planetary gear units that are integral with one another; an input means for inputting torque to the automatic transmission mechanism, clutches for operatively connecting predetermined ones of planetary gear elements of both of the planetary gear units to the input means and braking means for restricting the rotation of predetermined ones of planetary gear elements of both of the planetary gear units. The clutches are disposed adjacent one another at an end portion of the transmission for defining a clutch portion of the transmission; a first clutch portion which is attachable to the automatic transmission mechanism portion for comprising the clutch portion when attached thereto; a second clutch portion that is attachable to the automatic transmission mechanism portion in place of the first clutch portion for comprising the clutch portion when so attached. The first clutch portion comprising first clutch for operatively connecting the input means to a ring gear of the single planetary gear unit and a second clutch for operatively connecting the input means to a single gear of the automatic transmission mechanism portion. The second clutch portion comprising a the first clutch, the second clutch, and a third clutch for operatively connecting the input member to a ring gear of the dual planetary gear unit.

  11. My Child Needs or Has an Implantable Cardioverter-Defibrillator: What Should I Do?

    MedlinePlus

    ... Association . Circulation . 2011 ; 123 : 1454 – 1485 . OpenUrl FREE Full Text 5. ↵ Brown RT DeMaso DR . Pediatric heart disease . ... shock . Circulation . 2005 ; 111 : e380 – e382 . OpenUrl FREE Full Text 8. ↵ MedTees . http://www.cafepress.com/medtees/s_icd . ...

  12. Coping with Trauma and Stressful Events As a Patient with an Implantable Cardioverter-Defibrillator

    MedlinePlus

    ... 28, 2013 Jessica Ford From the Departments of Psychology (J.F., S.F.S.) and Department of Cardiovascular Sciences (S. ... site Samuel F. Sears From the Departments of Psychology (J.F., S.F.S.) and Department of Cardiovascular Sciences (S. ...

  13. 77 FR 20873 - Qualification of Drivers; Application for Exemptions; Implantable Cardioverter Defibrillators

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-06

    ... person has no current clinical diagnosis of myocardial infarction, angina pectoris, coronary... criteria indicate that: The term ``has no current clinical diagnosis of'' (1) a current cardiovascular.... The term ``known to be accompanied by'' is designed to include a clinical diagnosis of...

  14. Comparison of the specificity of implantable dual chamber defibrillator detection algorithms.

    PubMed

    Hintringer, Florian; Deibl, Martina; Berger, Thomas; Pachinger, Otmar; Roithinger, Franz Xaver

    2004-07-01

    The aim of the study was to compare the specificity of dual chamber ICDs detection algorithms for correct classification of supraventricular tachyarrhythmias derived from clinical studies according to their size to detect an impact of sample size on the specificity. Furthermore, the study sought to compare the specificities of detection algorithms calculated from clinical data with the specificity calculated from simulations of tachyarrhythmias. A survey was conducted of all available sources providing data regarding the specificity of five dual chamber ICDs. The specificity was correlated with the number of patients included, number of episodes, and number of supraventricular tachyarrhythmias recorded. The simulation was performed using tachyarrhythmias recorded in the electrophysiology laboratory. The range of the number of patients included into the studies was 78-1,029, the range of the total number of episodes recorded was 362-5,788, and the range of the number of supraventricular tachyarrhythmias used for calculation of the specificity for correct detection of these arrhythmias was 100 (Biotronik) to 1662 (Medtronic). The specificity for correct detection of supraventricular tachyarrhythmias was 90% (Biotronik), 89% (ELA Medical), 89% (Guidant), 68% (Medtronic), and 76% (St. Jude Medical). There was an inverse correlation (r = -0.9, P = 0.037) between the specificity for correct classification of supraventricular tachyarrhythmias and the number of patients. The specificity for correct detection of supraventricular tachyarrhythmias calculated from the simulation after correction for the clinical prevalence of the simulated tachyarrhythmias was 95% (Biotronik), 99% (ELA Medical), 94% (Guidant), 93% (Medtronic), and 92% (St. Jude Medical). In conclusion, the specificity of ICD detection algorithms calculated from clinical studies or registries may depend on the number of patients studied. Therefore, a direct comparison between different detection algorithms based on clinical data is difficult. In contrast, simulation of supraventricular tachyarrhythmias using a uniform database may be a better tool for direct comparison of the specificity of ICD detection algorithms.

  15. Dental Implants.

    PubMed

    Zohrabian, Vahe M; Sonick, Michael; Hwang, Debby; Abrahams, James J

    2015-10-01

    Dental implants restore function to near normal in partially or completely edentulous patients. A root-form implant is the most frequently used type of dental implant today. The basis for dental implants is osseointegration, in which osteoblasts grow and directly integrate with the surface of titanium posts surgically embedded into the jaw. Radiologic assessment is critical in the preoperative evaluation of the dental implant patient, as the exact height, width, and contour of the alveolar ridge must be determined. Moreover, the precise locations of the maxillary sinuses and mandibular canals, as well as their relationships to the site of implant surgery must be ascertained. As such, radiologists must be familiar with implant design and surgical placement, as well as augmentation procedures utilized in those patients with insufficient bone in the maxilla and mandible to support dental implants.

  16. Cochlear Implants

    MedlinePlus

    ... NIDCD A cochlear implant is a small, complex electronic device that can help to provide a sense ... are better able to hear, comprehend sound and music, and speak than their peers who receive implants ...

  17. Cochlear implant

    MedlinePlus

    ... antenna. This part of the implant receives the sound, converts the sound into an electrical signal, and sends it to ... implants allow deaf people to receive and process sounds and speech. However, these devices do not restore ...

  18. The hyperbolic strength-duration relationship of defibrillation threshold.

    PubMed

    Irnich, Werner

    2008-08-01

    Defibrillation with square-wave pulses has proved to possess hyperbolic strength-duration relationship. Does such a hyperbolic relation also exist for exponentially decaying pulses as they are commonly used today? This paper hypothesizes that exponentially decaying pulses obey hyperbolic strength-duration relationship, calculates the consequences, and advises of how such thresholds should be investigated. If the strength-duration relationship exists for current, the corresponding charge threshold must be a Weiss' straight threshold line. In analogy, for exponentially decaying pulses, the integral of the amplitude over pulse duration (PD) must be calculated as a function of PD. If this function is linearly correlated, the mean voltage possesses a hyperbolic strength-duration relationship, whereas the peak voltage does not. Peak amplitude curves possess minima shifting to the right with increasing time constant RC limiting the allowed range of useful PDs. To prove that exponentially decaying pulses have a hyperbolic relationship, testing must be done in six steps that are demonstrated with results published in literature. Mean voltages have, indeed, hyperbolic strength-duration relationship. Chronaxie is not calculated correctly as long as peak voltage thresholds are correlated and PDs are greater than allowed.

  19. Virtual electrodes around anatomical structures and their roles in defibrillation

    PubMed Central

    Vigmond, Edward; Bishop, Martin

    2017-01-01

    Background Virtual electrodes from structural/conductivity heterogeneities are known to elicit wavefront propagation, upon field-stimulation, and are thought to be important for defibrillation. In this work we investigate how the constitutive and geometrical parameters associated with such anatomical heterogeneities, represented by endo/epicardial surfaces and intramural surfaces in the form of blood-vessels, affect the virtual electrode patterns produced. Methods and results The steady-state bidomain model is used to obtain, using analytical and numerical methods, the virtual electrode patterns created around idealized endocardial trabeculations and blood-vessels. The virtual electrode pattern around blood-vessels is shown to be composed of two dominant effects; current traversing the vessel surface and conductivity heterogeneity from the fibre-architecture. The relative magnitudes of these two effects explain the swapping of the virtual electrode polarity observed, as a function of the vessel radius, and aid in the understanding of the virtual electrode patterns predicted by numerical bidomain modelling. The relatively high conductivity of blood, compared to myocardium, is shown to cause stronger depolarizations in the endocardial trabeculae grooves than the protrusions. Conclusions The results provide additional quantitative understanding of the virtual electrodes produced by small-scale ventricular anatomy, and highlight the importance of faithfully representing the physiology and the physics in the context of computational modelling of field stimulation. PMID:28253365

  20. [Training program on cardiopulmonary resuscitation with the use of automated external defibrillator in a university].

    PubMed

    Boaventura, Ana Paula; Miyadahira, Ana Maria Kazue

    2012-03-01

    Early defibrillation in cardiopulmonary resuscitation (CPR) receives increasing emphasis on its priority and rapidity. This is an experience report about the implementation of a training program in CPR using a defibrillator in a private university. The training program in basic CPR maneuvers was based on global guidelines, including a theorical course with practical demonstration of CPR maneuvers with the defibrillator, individual practical training and theoretical and practical assessments. About the performance of students in the practical assessment the mean scores obtained by students in the first stage of the course was 26.4 points, while in the second stage the mean was 252.8 points, in the theoretical assessment the mean in the first stage was 3.06 points and in the second 9.0 points. The implementation of programs like this contribute to the effective acquisition of knowledge (theory) and skill (pratice) for the care of CPR victims.

  1. [Electroconvulsive therapy and defibrillation in the paper. An analysis of the media].

    PubMed

    Hoffmann-Richter, U; Alder, B; Finzen, A

    1998-07-01

    In our study on Psychiatry, Mass Media and Public Opinion we made a content analysis of newspaper reports on ECT and electric defibrillation. We traced only few special articles on the subject in the 1994 and 1995 CD-Rom versions of the "Der Spiegel", The "Frankfurter Allgemeine Zeitung" (FAZ), the "Neue Zürcher Zeitung" (NZZ) and the "Berliner Tageszeitung" (taz), although the word "Elektroschock" was employed 118 times. Even in high standard newspapers the style of language becomes special when they deal with ECT. The articles are strongly biased and lack informations. In contrast to Defibrillation ECT is not generally accepted. Referring to ECT horror pictures of past psychiatry are cited. The language used is biased and discriminative. Referring to Defibrillation technical details are described and the language is neutral. The social representation of ECT is completely negative.

  2. ATMs, Coffee Shops Ideal Spots for Heart Defibrillators

    MedlinePlus

    ... stops beating altogether. A common cause is ventricular fibrillation, where the heart's main pumping chamber begins to ... If the cardiac arrest is caused by ventricular fibrillation, an AED will automatically detect that and deliver ...

  3. Defibrillation in the movies: a missed opportunity for public health education

    PubMed Central

    Mgbako, Ofole U.; Ha, Yoonhee P.; Ranard, Benjamin L.; Hypolite, Kendra A.; Sellers, Allison M.; Nadkarni, Lindsay D.; Becker, Lance B.; Asch, David A.; Merchant, Raina M.

    2014-01-01

    Aim To characterise defibrillation and cardiac arrest survival outcomes in movies. Methods Movies from 2003–2012 with defibrillation scenes were reviewed for patient and rescuer characteristics, scene characteristics, defibrillation characteristics, additional interventions, and cardiac arrest survival outcomes. Resuscitation actions were compared with chain of survival actions and the American Heart Association (AHA) Emergency Cardiovascular Care (ECC) 2020 Impact Goals. Cardiac arrest survival outcomes were compared with survival rates reported in the literature and targeted by the AHA ECC 2020 Impact Goals. Results Thirty-five scenes were identified in 32 movies. Twenty-five (71%) patients were male, and 29 (83%) rescuers were male. Intent of defibrillation was resuscitation in 29 (83%) scenes and harm in 6 (17%) scenes. Cardiac arrest was the indication for use in 23 (66%) scenes, and the heart rhythm was made known in 18 scenes (51%). When the heart rhythm was known, defibrillation was appropriately used for ventricular tachycardia or ventricular fibrillation in 5 (28%) scenes and inappropriately used for asystole in 7 (39%) scenes. In 8 scenes with in-hospital cardiac arrest, 7 (88%) patients survived, compared to survival rates of 23.9% reported in the literature and 38% targeted by an AHA ECC 2020 Impact Goal. In 12 movie scenes with out-of-hospital cardiac arrest, 8 (67%) patients survived, compared to survival rates of 7.9–9.5% reported in peer-reviewed literature and 15.8% targeted by an AHA ECC 2020 Impact Goal. Conclusion In movies, defibrillation and cardiac arrest survival outcomes are often portrayed inaccurately, representing missed opportunities for public health education. PMID:25241344

  4. Enhancing the Performance of Medical Implant Communication Systems through Cooperative Diversity.

    PubMed

    Hegyi, Barnabás; Levendovszky, János

    2010-01-01

    Battery-operated medical implants-such as pacemakers or cardioverter-defibrillators-have already been widely used in practical telemedicine and telecare applications. However, no solution has yet been found to mitigate the effect of the fading that the in-body to off-body communication channel is subject to. In this paper, we reveal and assess the potential of cooperative diversity to combat fading-hence to improve system performance-in medical implant communication systems. In the particular cooperative communication scenario we consider, multiple cooperating receiver units are installed across the room accommodating the patient with a medical implant inside his/her body. Our investigations have shown that the application of cooperative diversity is a promising approach to enhance the performance of medical implant communication systems in various aspects such as implant lifetime and communication link reliability.

  5. Cardiac Resynchronization Therapy Device Implantation in a Patient with Cardiogenic Shock under Percutaneous Mechanical Circulatory Support

    PubMed Central

    Lim, Kyunghee; Yang, Jeong Hoon; Park, Seung-Jung; Kim, Sun Hwa; Kang, Jiseok; Joh, Hyun Sung; Shin, Sun Hye

    2017-01-01

    65-year-old woman was admitted to our hospital with acute decompensated heart failure with reduced left ventricular ejection fraction and severe mitral regurgitation. Electrocardiography revealed a typical left bundle branch block and atrial fibrillation. Her condition deteriorated despite administering high-doses of inotropes and vasopressors. Pending a decision to therapy, venoarterial extracorporeal membrane oxygenation (ECMO) was performed when the patient underwent a cardiogenic shock. Although the hemodynamic status stabilized with ECMO support, weaning the patient from ECMO was not possible. Thus, we decided to perform cardiac resynchronization with defibrillator implantation as a “rescue” therapy. Five days post-implantation, the patient was successfully weaned from ECMO. PMID:28154601

  6. AUTOMATIC COUNTER

    DOEpatents

    Robinson, H.P.

    1960-06-01

    An automatic counter of alpha particle tracks recorded by a sensitive emulsion of a photographic plate is described. The counter includes a source of mcdulated dark-field illumination for developing light flashes from the recorded particle tracks as the photographic plate is automatically scanned in narrow strips. Photoelectric means convert the light flashes to proportional current pulses for application to an electronic counting circuit. Photoelectric means are further provided for developing a phase reference signal from the photographic plate in such a manner that signals arising from particle tracks not parallel to the edge of the plate are out of phase with the reference signal. The counting circuit includes provision for rejecting the out-of-phase signals resulting from unoriented tracks as well as signals resulting from spurious marks on the plate such as scratches, dust or grain clumpings, etc. The output of the circuit is hence indicative only of the tracks that would be counted by a human operator.

  7. Endodontic implants

    PubMed Central

    Yadav, Rakesh K.; Tikku, A. P.; Chandra, Anil; Wadhwani, K. K.; Ashutosh kr; Singh, Mayank

    2014-01-01

    Endodontic implants were introduced back in 1960. Endodontic implants enjoyed few successes and many failures. Various reasons for failures include improper case selection, improper use of materials and sealers and poor preparation for implants. Proper case selection had given remarkable long-term success. Two different cases are being presented here, which have been treated successfully with endodontic implants and mineral trioxide aggregate Fillapex (Andreaus, Brazil), an MTA based sealer. We suggest that carefully selected cases can give a higher success rate and this method should be considered as one of the treatment modalities. PMID:25298723

  8. Electrical defibrillation optimization: An automated, iterative parallel finite-element approach

    SciTech Connect

    Hutchinson, S.A.; Shadid, J.N.; Ng, K.T.; Nadeem, A.

    1997-04-01

    To date, optimization of electrode systems for electrical defibrillation has been limited to hand-selected electrode configurations. In this paper we present an automated approach which combines detailed, three-dimensional (3-D) finite element torso models with optimization techniques to provide a flexible analysis and design tool for electrical defibrillation optimization. Specifically, a parallel direct search (PDS) optimization technique is used with a representative objective function to find an electrode configuration which corresponds to the satisfaction of a postulated defibrillation criterion with a minimum amount of power and a low possibility of myocardium damage. For adequate representation of the thoracic inhomogeneities, 3-D finite-element torso models are used in the objective function computations. The CPU-intensive finite-element calculations required for the objective function evaluation have been implemented on a message-passing parallel computer in order to complete the optimization calculations in a timely manner. To illustrate the optimization procedure, it has been applied to a representative electrode configuration for transmyocardial defibrillation, namely the subcutaneous patch-right ventricular catheter (SP-RVC) system. Sensitivity of the optimal solutions to various tissue conductivities has been studied. 39 refs., 9 figs., 2 tabs.

  9. Cardiac Arrest During Medically-Supervised Exercise Training: A Report of Fifteen Successful Defibrillations.

    ERIC Educational Resources Information Center

    Pyfer, Howard R.; And Others

    The Cardio-Pulmonary Research Institute conducted an exercise program for men with a history of coronary heart disease. Over 7 years, there were 15 cases of cardiac arrest during exercise (one for every 6,000 man-hours of exercise). Trained medical personnel were present in all cases, and all were resuscitated by electrical defibrillation with no…

  10. Just 17 U.S. States Require Defibrillators in Some Schools

    MedlinePlus

    ... news/fullstory_164305.html Just 17 U.S. States Require Defibrillators in Some Schools Easy-to-use portable ... but only about one-third of U.S. states require the devices in at least some schools, a ...

  11. Comparison of the effects of removal of chest hair with not doing so before external defibrillation on transthoracic impedance.

    PubMed

    Sado, Daniel M; Deakin, Charles D; Petley, Graham W; Clewlow, Frank

    2004-01-01

    Chest hair contributes significantly to transthoracic impedance (TTI) during defibrillation. The magnitude of this effect has not been established using external paddles. We compared TTI in 40 men before elective cardiac surgery, and before and after shaving their chests. Chest hair causes a significant increase in TTI during external defibrillation, the magnitude of the effect being related to both the quantity of hair and force applied to the defibrillation paddles. When the chests of nonhirsute patients were shaved, a decrease in TTI occurred, which was probably related to the creation of low-impedance pathways through skin abrasions.

  12. Automatic transmission

    SciTech Connect

    Ohkubo, M.

    1988-02-16

    An automatic transmission is described combining a stator reversing type torque converter and speed changer having first and second sun gears comprising: (a) a planetary gear train composed of first and second planetary gears sharing one planetary carrier in common; (b) a clutch and requisite brakes to control the planetary gear train; and (c) a speed-increasing or speed-decreasing mechanism is installed both in between a turbine shaft coupled to a turbine of the stator reversing type torque converter and the first sun gear of the speed changer, and in between a stator shaft coupled to a reversing stator and the second sun gear of the speed changer.

  13. Automatic transmission

    SciTech Connect

    Miki, N.

    1988-10-11

    This patent describes an automatic transmission including a fluid torque converter, a first gear unit having three forward-speed gears and a single reverse gear, a second gear unit having a low-speed gear and a high-speed gear, and a hydraulic control system, the hydraulic control system comprising: a source of pressurized fluid; a first shift valve for controlling the shifting between the first-speed gear and the second-speed gear of the first gear unit; a second shift valve for controlling the shifting between the second-speed gear and the third-speed gear of the first gear unit; a third shift valve equipped with a spool having two positions for controlling the shifting between the low-speed gear and the high-speed gear of the second gear unit; a manual selector valve having a plurality of shift positions for distributing the pressurized fluid supply from the source of pressurized fluid to the first, second and third shift valves respectively; first, second and third solenoid valves corresponding to the first, second and third shift valves, respectively for independently controlling the operation of the respective shift valves, thereby establishing a six forward-speed automatic transmission by combining the low-speed gear and the high-speed gear of the second gear unit with each of the first-speed gear, the second speed gear and the third-speed gear of the first gear unit; and means to fixedly position the spool of the third shift valve at one of the two positions by supplying the pressurized fluid to the third shift valve when the manual selector valve is shifted to a particular shift position, thereby locking the second gear unit in one of low-speed gear and the high-speed gear, whereby the six forward-speed automatic transmission is converted to a three forward-speed automatic transmission when the manual selector valve is shifted to the particular shift position.

  14. Arrhythmias in Patients with Cardiac Implantable Electrical Devices after Implantation of a Left Ventricular Assist Device.

    PubMed

    Rosenbaum, Andrew N; Kremers, Walter K; Duval, Sue; Sakaguchi, Scott; John, Ranjit; Eckman, Peter M

    2016-01-01

    Utilization of continuous-flow left ventricular assist devices (CF-LVADs) for advanced heart failure is increasing, and the role of cardiac implantable electrical devices (CIED) is unclear. Prior studies of the incidence of arrhythmias and shocks are frequently limited by ascertainment. One hundred and seventy-eight patients were examined with a previous CIED who were implanted with a CF-LVAD. Medical history, medications, and CIED data from device interrogations were gathered. A cardiac surgery control group (n = 38) was obtained to control for surgical factors. Several clinically significant events increased after LVAD implantation: treated-zone ventricular arrhythmias (VA; p < 0.01), monitored-zone VA (p < 0.01), antitachycardia pacing (ATP)-terminated episodes (p < 0.01), and shocks (p = 0.01), although administered shocks later decreased (p < 0.01). Presence of a preimplant VA was associated with postoperative VA (odds ratio [OR]: 4.31; confidence interval [CI]: 1.5-12.3, p < 0.01). Relative to cardiac surgery, LVAD patients experienced more perioperative events (i.e., monitored VAs and shocks, p < 0.01 and p = 0.04). Neither implantable cardioverter defibrillator (ICD) shocks before implant nor early or late postimplant arrhythmias or shocks predicted survival (p = 0.07, p = 0.55, and p = 0.55). Our experience demonstrates time-dependent effects on clinically significant arrhythmias after LVAD implantation, including evidence that early LVAD-related arrhythmias may be caused by the unique arrhythmogenic effects of VAD implant.

  15. Breast Implants

    MedlinePlus

    ... sale in the United States: saline-filled and silicone gel-filled. Both types have a silicone outer shell. They vary in size, shell thickness, ... implant them. Provide information on saline-filled and silicone gel-filled breast implants, including data supporting a ...

  16. Electromagnetic compatibility of electronic implants--review of the literature.

    PubMed

    Kainz, W; Neubauer, G; Alesch, F; Schmid, G; Jahn, O

    2001-12-17

    The aim of the article was to provide an overview of published studies regarding the electromagnetic compatibility (EMC) of electronic implants. The available literature was sorted according to combinations of implant types and sources of interference. Several experiments concerning the susceptibility of pacemakers to mobile phones have been performed. The results of these experiments suggest measures that may be used to prevent the disturbance of pacemakers. For instance, instead of carrying the activated mobile phone in the breast pocket it is recommended that a distance of 30 cm be maintained between the pacemaker and the mobile phone, and that the mobile phone be used on the contralateral side of the pacemaker's location. Similar measures may be recommended for patients with implantable cardioverter defibrillators when using mobile phones. Patients with electronic implants should walk rapidly through anti theft-devices because some of these devices are liable to disturb implants. Patients with cardiac pacemakers should not be subjected to magnetic resonance imaging as far as possible. For a variety of combinations of implants and interference sources, e.g. cardiac pacemakers and base station antennas, no studies were found in the literature. It is strongly recommended that trials be carried out to evaluate the potential risk for patients in these settings.

  17. Automatic transmission

    SciTech Connect

    Aoki, H.

    1989-03-21

    An automatic transmission is described, comprising: a torque converter including an impeller having a connected member, a turbine having an input member and a reactor; and an automatic transmission mechanism having first to third clutches and plural gear units including a single planetary gear unit with a ring gear and a dual planetary gear unit with a ring gear. The single and dual planetary gear units have respective carriers integrally coupled with each other and respective sun gears integrally coupled with each other, the input member of the turbine being coupled with the ring gear of the single planetary gear unit through the first clutch, and being coupled with the sun gear through the second clutch. The connected member of the impeller is coupled with the ring gear of the dual planetary gear of the dual planetary gear unit is made to be and ring gear of the dual planetary gear unit is made to be restrained as required, and the carrier is coupled with an output member.

  18. Implantable Smart Technologies (IST): Defining the 'Sting' in Data and Device.

    PubMed

    Haddow, Gill; Harmon, Shawn H E; Gilman, Leah

    2016-09-01

    In a world surrounded by smart objects from sensors to automated medical devices, the ubiquity of 'smart' seems matched only by its lack of clarity. In this article, we use our discussions with expert stakeholders working in areas of implantable medical devices such as cochlear implants, implantable cardiac defibrillators, deep brain stimulators and in vivo biosensors to interrogate the difference facets of smart in 'implantable smart technologies', considering also whether regulation needs to respond to the autonomy that such artefacts carry within them. We discover that when smart technology is deconstructed it is a slippery and multi-layered concept. A device's ability to sense and transmit data and automate medicine can be associated with the 'sting' of autonomy being disassociated from human control as well as affecting individual, group, and social environments.

  19. Implantable rhythm devices and electromagnetic interference: myth or reality?

    PubMed

    Dyrda, Katia; Khairy, Paul

    2008-07-01

    Current medical guidelines have prompted implementation of increasing numbers of implantable rhythm devices, be they pacemakers, internal cardioverter-defibrillators or loop recorders. These devices rely on complex microcircuitry and use electromagnetic waves for communication. They are, therefore, susceptible to interference from surrounding electromagnetic radiation and magnetic energy. Hermetic shielding in metallic cases, filters, interference rejection circuits and bipolar sensing have contributed to their relative resistance to electromagnetic interference (EMI) in household and workplace environments. Device interactions have occurred in hospitals where EMI sources are ubiquitous, including radiation, electrocautery and MRI exposures. However, with rapidly evolving technology, devices and potential sources of EMI continue to change. This review provides a contemporary overview of the current state of knowledge regarding risks attributable to EMI; highlights current limitations of implantable rhythm devices; and attempts to distinguish myths from realities.

  20. Preferred tools and techniques for implantation of cardiac electronic devices in Europe: results of the European Heart Rhythm Association survey.

    PubMed

    Bongiorni, Maria Grazia; Proclemer, Alessandro; Dobreanu, Dan; Marinskis, Germanas; Pison, Laurent; Blomstrom-Lundqvist, Carina

    2013-11-01

    The aim of this European Heart Rhythm Association (EHRA) survey was to assess clinical practice in relation to the tools and techniques used for cardiac implantable electronic devices procedures in the European countries. Responses to the questionnaire were received from 62 members of the EHRA research network. The survey involved high-, medium-, and low-volume implanting centres, performing, respectively, more than 200, 100-199 and under 100 implants per year. The following topics were explored: the side approach for implantation, surgical techniques for pocket incision, first venous access for lead implantation, preference of lead fixation, preferred coil number for implantable cardioverter-defibrillator (ICD) leads, right ventricular pacing site, generator placement site, subcutaneous ICD implantation, specific tools and techniques for cardiac resynchronization therapy (CRT), lead implantation sequence in CRT, coronary sinus cannulation technique, target site for left ventricular lead placement, strategy in left ventricular lead implant failure, mean CRT implantation time, optimization of the atrioventricular (AV) and ventriculo-ventricular intervals, CRT implants in patients with permanent atrial fibrillation, AV node ablation in patients with permanent AF. This panoramic view allows us to find out the operator preferences regarding the techniques and tools for device implantation in Europe. The results showed different practices in all the fields we investigated, nevertheless the survey also outlines a good adherence to the common standards and recommendations.

  1. Integration of Attributes from Non-Linear Characterization of Cardiovascular Time-Series for Prediction of Defibrillation Outcomes

    PubMed Central

    Shandilya, Sharad; Kurz, Michael C.; Ward, Kevin R.; Najarian, Kayvan

    2016-01-01

    Objective The timing of defibrillation is mostly at arbitrary intervals during cardio-pulmonary resuscitation (CPR), rather than during intervals when the out-of-hospital cardiac arrest (OOH-CA) patient is physiologically primed for successful countershock. Interruptions to CPR may negatively impact defibrillation success. Multiple defibrillations can be associated with decreased post-resuscitation myocardial function. We hypothesize that a more complete picture of the cardiovascular system can be gained through non-linear dynamics and integration of multiple physiologic measures from biomedical signals. Materials and Methods Retrospective analysis of 153 anonymized OOH-CA patients who received at least one defibrillation for ventricular fibrillation (VF) was undertaken. A machine learning model, termed Multiple Domain Integrative (MDI) model, was developed to predict defibrillation success. We explore the rationale for non-linear dynamics and statistically validate heuristics involved in feature extraction for model development. Performance of MDI is then compared to the amplitude spectrum area (AMSA) technique. Results 358 defibrillations were evaluated (218 unsuccessful and 140 successful). Non-linear properties (Lyapunov exponent > 0) of the ECG signals indicate a chaotic nature and validate the use of novel non-linear dynamic methods for feature extraction. Classification using MDI yielded ROC-AUC of 83.2% and accuracy of 78.8%, for the model built with ECG data only. Utilizing 10-fold cross-validation, at 80% specificity level, MDI (74% sensitivity) outperformed AMSA (53.6% sensitivity). At 90% specificity level, MDI had 68.4% sensitivity while AMSA had 43.3% sensitivity. Integrating available end-tidal carbon dioxide features into MDI, for the available 48 defibrillations, boosted ROC-AUC to 93.8% and accuracy to 83.3% at 80% sensitivity. Conclusion At clinically relevant sensitivity thresholds, the MDI provides improved performance as compared to AMSA

  2. Automatic transmission

    SciTech Connect

    Hamane, M.; Ohri, H.

    1989-03-21

    This patent describes an automatic transmission connected between a drive shaft and a driven shaft and comprising: a planetary gear mechanism including a first gear driven by the drive shaft, a second gear operatively engaged with the first gear to transmit speed change output to the driven shaft, and a third gear operatively engaged with the second gear to control the operation thereof; centrifugally operated clutch means for driving the first gear and the second gear. It also includes a ratchet type one-way clutch for permitting rotation of the third gear in the same direction as that of the drive shaft but preventing rotation in the reverse direction; the clutch means comprising a ratchet pawl supporting plate coaxially disposed relative to the drive shaft and integrally connected to the third gear, the ratchet pawl supporting plate including outwardly projection radial projections united with one another at base portions thereof.

  3. Automatic transmission

    SciTech Connect

    Meyman, U.

    1987-03-10

    An automatic transmission is described comprising wheel members each having discs defining an inner space therebetween; turnable blades and vane members located in the inner space between the discs of at least one of the wheel members, the turnable blades being mechanically connected with the vane members. Each of the turnable blades has an inner surface and an outer surface formed by circular cylindrical surfaces having a common axis, each of the turnable blades being turnable about the common axis of the circular cylindrical surfaces forming the inner and outer surfaces of the respective blade; levers turnable about the axes and supporting the blades; the discs having openings extending coaxially with the surfaces which describe the blades. The blades are partially received in the openings of the discs; and a housing accommodating the wheel members and the turnable blades and the vane members.

  4. Tachyarrhythmia Cycle Length in Appropriate versus Inappropriate Defibrillator Shocks in Brugada Syndrome, Early Repolarization Syndrome, or Idiopathic Ventricular Fibrillation

    PubMed Central

    Lee, Woo Seok; Kwon, Chang-Hee; Choi, Jin Hee; Jo, Uk; Kim, Yoo Ri; Nam, Gi-Byoung; Choi, Kee-Joon; Kim, You-Ho

    2016-01-01

    Background and Objectives Implantable cardioverter–defibrillators (ICDs) are indicated in patients with Brugada syndrome (BS), early repolarization syndrome (ERS), or idiopathic ventricular fibrillation (IVF) who are at high risk for sudden cardiac death. The optimal ICD programming for reducing inappropriate shocks in these patients remains to be determined. We investigated the difference in the mean cycle length of tachyarrhythmias that activated either appropriate or inappropriate ICD shocks in these three patient groups to determine the optimal ventricular fibrillation (VF) zone for minimizing inappropriate ICD shocks. Subjects and Methods We selected 41 patients (35 men) (mean age±standard deviation=42.6±13.0 year) who received ICD shocks between April 1996 and April 2014 to treat BS (n=24), ERS (n=9), or IVF (n=8). Clinical and ICD interrogation data were retrospectively collected and analyzed for all events with ICD shocks. Results Of the 244 episodes, 180 (73.8%) shocks were appropriate and 64 (26.2%) were inappropriate. The mean cycle lengths of the tachyarrhythmias that activated appropriate and inappropriate shocks were 178.9±28.7 ms and 284.8±24.4 ms, respectively (p<0.001). The cutoff value with the highest sensitivity and specificity for discriminating between appropriate and inappropriate shocks was 235 ms (sensitivity, 98.4%; specificity, 95.6%). When we programmed a single VF zone of ≤270 ms, inappropriate ICD shocks were reduced by 70.5% and appropriate shocks were missed in 1.7% of these patients. Conclusion Programming of a single VF zone of ≤270 ms in patients with BS, ERS, or IVF could reduce inappropriate ICD shocks, with a low risk of missing appropriate shocks. PMID:27014348

  5. Histrelin Implant

    MedlinePlus

    ... implant (Supprelin LA) is used to treat central precocious puberty (CPP; a condition causing children to enter puberty too soon, resulting in faster than normal bone growth and development of sexual characteristics) in girls ...

  6. Penile Implants

    MedlinePlus

    ... placed inside the penis to allow men with erectile dysfunction (ED) to get an erection. Penile implants are ... complications and follow-up care. For most men, erectile dysfunction can be successfully treated with medications or use ...

  7. Cochlear implants.

    PubMed

    Connell, Sarah S; Balkany, Thomas J

    2006-08-01

    Cochlear implants are cost-effective auditory prostheses that safely provide a high-quality sensation of hearing to adults who are severely or profoundly deaf. In the past 5 years, progress has been made in hardware and software design, candidate selection, surgical techniques, device programming, education and rehabilitation,and, most importantly, outcomes. Cochlear implantation in the elderly is well tolerated and provides marked improvement in auditory performance and psychosocial functioning.

  8. A Study to Improve Communication Between Clinicians and Patients With Advanced Heart Failure: Methods and Challenges Behind the Working to Improve diScussions about DefibrillatOr Management (WISDOM) Trial

    PubMed Central

    Goldstein, Nathan E.; Kalman, Jill; Kutner, Jean S.; Fromme, Erik K.; Hutchinson, Mathew D.; Lipman, Hannah I.; Matlock, Daniel D.; Swetz, Keith M.; Lampert, Rachel; Herasme, Omarys; Morrison, R. Sean

    2014-01-01

    We report the challenges of the Working to Improve diScussions about DefibrillatOr Management (WISDOM) Trial, our novel, multicenter trial aimed at improving communication between cardiology clinicians and their patients with advanced heart failure (HF) who have implantable cardioverter defibrillators (ICDs). The study objectives are to: 1) increase ICD deactivation conversations; 2) increase the number of ICDs deactivated; and 3) improve psychological outcomes in bereaved caregivers. The unit of randomization is the hospital, the intervention is aimed at HF clinicians, and the patient and caregiver are the units of analysis. Three hospitals were randomized to usual care and three to intervention. The intervention consists of an interactive educational session, clinician reminders, and individualized feedback. We enroll patients with advanced HF and their caregivers, and then we regularly survey them to evaluate whether the intervention has improved communication between them and their heart failure providers. We encountered three implementation barriers. First, there were Institutional Review Board (IRB) concerns at two sites because of the palliative nature of the study. Second, we had difficulty in creating entry criteria that accurately identified a HF population at high risk of dying. Third, we had to adapt our entry criteria to the changing landscape of ventricular assist devices and cardiac transplant eligibility. Here we present our novel solutions to the difficulties we encountered. Our work has the ability to enhance conduct of future studies focusing on improving care for patients with advanced illness. PMID:24768595

  9. Contraceptive implants.

    PubMed

    McDonald-Mosley, Raegan; Burke, Anne E

    2010-03-01

    Implantable contraception has been extensively used worldwide. Implants are one of the most effective and reversible methods of contraception available. These devices may be particularly appropriate for certain populations of women, including women who cannot use estrogen-containing contraception. Implants are safe for use by women with many chronic medical problems. The newest implant, Implanon (Organon International, Oss, The Netherlands), is the only device currently available in the United States and was approved in 2006. It is registered for 3 years of pregnancy prevention. Contraceptive implants have failure rates similar to tubal ligation, and yet they are readily reversible with a return to fertility within days of removal. Moreover, these contraceptive devices can be safely placed in the immediate postpartum period, ensuring good contraceptive coverage for women who may be at risk for an unintended pregnancy. Irregular bleeding is a common side effect for all progestin-only contraceptive implants. Preinsertion counseling should address possible side effects, and treatment may be offered to women who experience prolonged or frequent bleeding.

  10. [Interferences and cardiac pacemakers--defibrillators. Results of in vivo experiments and radio frequencies].

    PubMed

    Trigano, J A

    2003-04-01

    Interference with cardiac pacemakers and defibrillators by cellular phone and electronic article surveillance systems is shown in experimental studies with disparate findings. Interaction occurrence in real life is a convincing but rare experience. Device model, distance, power output and technology of the source are different and sometimes uncontrollable factors. As a result it remains difficult to quantify the true incidence of interaction and associated health risk. Nevertheless, simple recommendations commonly help the patients to prevent the interference.

  11. First Report of Survival in Refractory Ventricular Fibrillation After Dual-Axis Defibrillation and Esmolol Administration

    PubMed Central

    Boehm, Kevin M.; Keyes, Daniel C.; Mader, Laura E; Moccia, J. Michelle

    2016-01-01

    There is a subset of patients who suffer a witnessed ventricular fibrillation (VF) arrest and despite receiving reasonable care with medications (epinephrine and amiodarone) and multiple defibrillations (3+ attempts at 200 joules of biphasic current) remain in refractory VF (RVF), also known as electrical storm. The mortality for these patients is as high as 97%. We present the case of a patient who, with a novel approach, survived RVF to outpatient follow up. PMID:27833686

  12. Hidden in Plain Sight: A Crowdsourced Public Art Contest to Make Automated External Defibrillators More Visible

    PubMed Central

    Griffis, Heather M.; Kilaru, Austin S.; Sellers, Allison M.; Hershey, John C.; Hill, Shawndra S.; Kramer-Golinkoff, Emily; Nadkarni, Lindsay; Debski, Margaret M.; Padrez, Kevin A.; Becker, Lance B.; Asch, David A.

    2014-01-01

    Objectives. We sought to explore the feasibility of using a crowdsourcing study to promote awareness about automated external defibrillators (AEDs) and their locations. Methods. The Defibrillator Design Challenge was an online initiative that asked the public to create educational designs that would enhance AED visibility, which took place over 8 weeks, from February 6, 2014, to April 6, 2014. Participants were encouraged to vote for AED designs and share designs on social media for points. Using a mixed-methods study design, we measured participant demographics and motivations, design characteristics, dissemination, and Web site engagement. Results. Over 8 weeks, there were 13 992 unique Web site visitors; 119 submitted designs and 2140 voted. The designs were shared 48 254 times on Facebook and Twitter. Most designers–voters reported that they participated to contribute to an important cause (44%) rather than to win money (0.8%). Design themes included: empowerment, location awareness, objects (e.g., wings, lightning, batteries, lifebuoys), and others. Conclusions. The Defibrillator Design Challenge engaged a broad audience to generate AED designs and foster awareness. This project provides a framework for using design and contest architecture to promote health messages. PMID:25320902

  13. Optogenetics design of mechanistically-based stimulation patterns for cardiac defibrillation

    PubMed Central

    Crocini, Claudia; Ferrantini, Cecilia; Coppini, Raffaele; Scardigli, Marina; Yan, Ping; Loew, Leslie M.; Smith, Godfrey; Cerbai, Elisabetta; Poggesi, Corrado; Pavone, Francesco S.; Sacconi, Leonardo

    2016-01-01

    Current rescue therapies for life-threatening arrhythmias ignore the pathological electro-anatomical substrate and base their efficacy on a generalized electrical discharge. Here, we developed an all-optical platform to examine less invasive defibrillation strategies. An ultrafast wide-field macroscope was developed to optically map action potential propagation with a red-shifted voltage sensitive dye in whole mouse hearts. The macroscope was implemented with a random-access scanning head capable of drawing arbitrarily-chosen stimulation patterns with sub-millisecond temporal resolution allowing precise epicardial activation of Channelrhodopsin2 (ChR2). We employed this optical system in the setting of ventricular tachycardia to optimize mechanistic, multi-barrier cardioversion/defibrillation patterns. Multiple regions of conduction block were created with a very high cardioversion efficiency but with lower energy requirements as compared to whole ventricle interventions to interrupt arrhythmias. This work demonstrates that defibrillation energies can be substantially reduced by applying discrete stimulation patterns and promotes the progress of current anti-arrhythmic strategies. PMID:27748433

  14. Automatic transmission

    SciTech Connect

    Miura, M.; Inuzuka, T.

    1986-08-26

    1. An automatic transmission with four forward speeds and one reverse position, is described which consists of: an input shaft; an output member; first and second planetary gear sets each having a sun gear, a ring gear and a carrier supporting a pinion in mesh with the sun gear and ring gear; the carrier of the first gear set, the ring gear of the second gear set and the output member all being connected; the ring gear of the first gear set connected to the carrier of the second gear set; a first clutch means for selectively connecting the input shaft to the sun gear of the first gear set, including friction elements, a piston selectively engaging the friction elements and a fluid servo in which hydraulic fluid is selectively supplied to the piston; a second clutch means for selectively connecting the input shaft to the sun gear of the second gear set a third clutch means for selectively connecting the input shaft to the carrier of the second gear set including friction elements, a piston selectively engaging the friction elements and a fluid servo in which hydraulic fluid is selectively supplied to the piston; a first drive-establishing means for selectively preventing rotation of the ring gear of the first gear set and the carrier of the second gear set in only one direction and, alternatively, in any direction; a second drive-establishing means for selectively preventing rotation of the sun gear of the second gear set; and a drum being open to the first planetary gear set, with a cylindrical intermediate wall, an inner peripheral wall and outer peripheral wall and forming the hydraulic servos of the first and third clutch means between the intermediate wall and the inner peripheral wall and between the intermediate wall and the outer peripheral wall respectively.

  15. Persistent Left Superior Vena Cava in Patients Undergoing Cardiac Device Implantation: Clinical and Long-Term Data

    PubMed Central

    Petrac, Dubravko; Radeljic, Vjekoslav; Pavlovic, Nikola; Manola, Sime; Delic-Brkljacic, Diana

    2013-01-01

    Background Persistent left superior vena cava (LSVC) is a rare congenital venous anomaly that may be found at the time of cardiac device lead insertion. Methods In this case series, we present clinical and long-term data of five patients with LSVC who underwent pacemaker (PM) or cardioverter defibrillator (ICD) implantation during the period of 10 years. Results Left-sided venous approach was used for device implantation in 3 patients with standard PM indications, whereas a right-sided venous approach and an epicardial approach had to be used in 2 patients who needed an ICD and biventricular PM, respectively. In post implantation period of 44 ± 29 months, one patient died due to stroke, one underwent heart transplantation, and 3 had atrial fibrillation. Conclusion The long-term outcome of patients with persistent LSVC and implanted cardiac devices is mostly influenced by the presence of underlying heart disease.

  16. Cochlear Implants

    MedlinePlus

    ... outside of the body, behind the ear. A second part is surgically placed under the skin. An implant does not restore normal hearing. It can help a person understand speech. Children and adults can benefit from them. National Institute on Deafness and Other Communication Disorders

  17. Monophasic versus biphasic defibrillation for pediatric out-of-hospital cardiac arrest patients: a nationwide population-based study in Japan

    PubMed Central

    2012-01-01

    Introduction Conventional monophasic defibrillators for out-of-hospital cardiac-arrest patients have been replaced with biphasic defibrillators. However, the advantage of biphasic over monophasic defibrillation for pediatric out-of-hospital cardiac-arrest patients remains unknown. This study aimed to compare the survival outcomes of pediatric out-of-hospital cardiac-arrest patients who underwent monophasic defibrillation with those who underwent biphasic defibrillation. Methods This prospective, nationwide, population-based observational study included pediatric out-of-hospital cardiac-arrest patients from January 1, 2005, to December 31, 2009. The primary outcome measure was survival at 1 month with minimal neurologic impairment. The secondary outcome measures were survival at 1 month and the return of spontaneous circulation before hospital arrival. Multivariable logistic regression analysis was performed to identify the independent association between defibrillator type (monophasic or biphasic) and outcomes. Results Among 5,628 pediatric out-of-hospital cardiac-arrest patients (1 through 17 years old), 430 who received defibrillation shock with monophasic or biphasic defibrillator were analyzed. The number of patients who received defibrillation shock with monophasic defibrillator was 127 (30%), and 303 (70%) received defibrillation shock with biphasic defibrillator. The survival rates at 1 month with minimal neurologic impairment were 17.5% and 24.4%, the survival rates at 1 month were 32.3% and 35.6%, and the rates of return of spontaneous circulation before hospital arrival were 24.4% and 27.4% in the monophasic and biphasic defibrillator groups, respectively. Hierarchic logistic regression analyses by using generalized estimation equations found no significant difference between the two groups in terms of 1-month survival with minimal neurologic impairment (odds ratio (OR), 1.57; 95% confidence interval (CI), 0.87 to 2.83; P = 0.14) and 1-month survival (OR

  18. Cardiac device implantation in Fabry disease

    PubMed Central

    Sené, Thomas; Lidove, Olivier; Sebbah, Joel; Darondel, Jean-Marc; Picard, Hervé; Aaron, Laurent; Fain, Olivier; Zenone, Thierry; Joly, Dominique; Charron, Philippe; Ziza, Jean-Marc

    2016-01-01

    Abstract The incidence and predictive factors of arrhythmias and/or conduction abnormalities (ACAs) requiring cardiac device (CD) implantation are poorly characterized in Fabry disease (FD). The aim of our retrospective study was to determine the prevalence, incidence, and factors associated with ACA requiring CD implantation in a monocentric cohort of patients with confirmed FD who were followed up in a department of internal medicine and reference center for FD. Forty-nine patients (20M, 29F) were included. Nine patients (4M, 5F; 18%) had at least one episode of ACA leading to device therapy. Six patients (4M/2F) required a pacemaker (PM) for sinus node dysfunction (n = 4) or atrioventricular disease (n = 2). One female patient required an internal cardioverter-defibrillator (ICD) to prevent sudden cardiac death because of nonsustained ventricular tachycardia (nSVT). One female patient required PM-ICD for sinus node dysfunction and nSVT. One patient underwent CD implantation before the diagnosis of FD. The annual rate of CD implantation was estimated at 1.90 per 100 person years. On univariate analysis at the end of the follow-up period, the factors associated with ACAs requiring CD implantation were as follows: delayed diagnosis of FD, delayed initiation of enzyme replacement therapy, age at the last follow-up visit, and severe multiorgan phenotype (hypertrophic cardiomyopathy, chronic kidney disease, and/or sensorineural hearing loss). On multivariate analysis, age at diagnosis of FD and age at the last follow-up visit were independently associated with an increased risk of ACAs requiring CD (P < 0.05). Considering the high frequency of ACAs requiring CD implantation and the risk of sudden death in patients with FD, regular monitoring is mandatory, especially in patients with a late diagnosis of FD and/or with a severe phenotype. Regular Holter ECGs, therapeutic education of patients, and deliverance of an emergency card including a phenotype

  19. Hazard report. Shift checks and semiannual preventive maintenance are important in detecting critical failures in Zoll M series defibrillators.

    PubMed

    2009-05-01

    The manufacturer-recommended shift check for Zoll M Series defibrillators cannot detect some critical failures that could inhibit defibrillation or pacing. To improve detection of these failures and to limit their impact on patient care, hospitals should perform not only the routine perform not only the routine shift check, but also the twice-annual preventive maintenance procedure recommended by Zoll. Additionally, units exhibiting an error code--even one that appears to resolve itself--should be immediately removed from service and evaluated by the clinical engineering department.

  20. Attitudes of Ohio dentists and dental hygienists on the use of automated external defibrillators.

    PubMed

    Kandray, Diane P; Pieren, Jennifer A; Benner, Randall W

    2007-04-01

    The American Heart Association reports that approximately 220,000 people die each year of sudden cardiac arrest. In ventricular fibrillation (VF), the most common abnormal heart rhythm that causes cardiac arrest, the heart's electrical impulses suddenly become chaotic, often without warning. Death will follow within minutes if the victim is not treated appropriately, and the only known treatment is defibrillation. An automated external defibrillator (AED) can restore a victim's normal heart rhythm by providing defibrillation. The purpose of this study was to gather data from dentists and dental hygienists in Ohio on their use of and attitudes toward using AEDs in dental offices. Six percent of Ohio dentists and dental hygienists were randomly selected to receive a twenty-three question survey related to their use of and attitudes toward their use of AEDs in dental offices. Thirty-three percent (244) of the surveys were returned; 41 percent of the respondents were dentists, and 59 percent were dental hygienists. Six percent said they have had to administer nitroglycerin to a patient during a dental visit; 5 percent have performed CPR on a patient in the dental office; and 78 percent said their last CPR training course included training on an AED. Eleven percent said there was an AED at their dental office. With the increased likelihood of dealing with a cardiac emergency in the dental office setting and the willingness of dental professionals to use an AED, all dental offices should consider obtaining an AED. Dental educators should become familiar with current protocols for handling cardiac medical emergencies in the dental office and prepare dental and dental hygiene students with the skills necessary to manage patients with cardiac emergencies. Graduating dental students entering private practice may want to consider the AED as part of their medical emergency office protocol.

  1. Short Implants: New Horizon in Implant Dentistry.

    PubMed

    Jain, Neha; Gulati, Manisha; Garg, Meenu; Pathak, Chetan

    2016-09-01

    The choice of implant length is an essential factor in deciding the survival rates of these implants and the overall success of the prosthesis. Placing an implant in the posterior part of the maxilla and mandible has always been very critical due to poor bone quality and quantity. Long implants can be placed in association with complex surgical procedures such as sinus lift and bone augmentation. These techniques are associated with higher cost, increased treatment time and greater morbidity. Hence, there is need for a less invasive treatment option in areas of poor bone quantity and quality. Data related to survival rates of short implants, their design and prosthetic considerations has been compiled and structured in this manuscript with emphasis on the indications, advantages of short implants and critical biomechanical factors to be taken into consideration when choosing to place them. Studies have shown that comparable success rates can be achieved with short implants as those with long implants by decreasing the lateral forces to the prosthesis, eliminating cantilevers, increasing implant surface area and improving implant to abutment connection. Short implants can be considered as an effective treatment alternative in resorbed ridges. Short implants can be considered as a viable treatment option in atrophic ridge cases in order to avoid complex surgical procedures required to place long implants. With improvement in the implant surface geometry and surface texture, there is an increase in the bone implant contact area which provides a good primary stability during osseo-integration.

  2. Short Implants: New Horizon in Implant Dentistry

    PubMed Central

    Gulati, Manisha; Garg, Meenu; Pathak, Chetan

    2016-01-01

    The choice of implant length is an essential factor in deciding the survival rates of these implants and the overall success of the prosthesis. Placing an implant in the posterior part of the maxilla and mandible has always been very critical due to poor bone quality and quantity. Long implants can be placed in association with complex surgical procedures such as sinus lift and bone augmentation. These techniques are associated with higher cost, increased treatment time and greater morbidity. Hence, there is need for a less invasive treatment option in areas of poor bone quantity and quality. Data related to survival rates of short implants, their design and prosthetic considerations has been compiled and structured in this manuscript with emphasis on the indications, advantages of short implants and critical biomechanical factors to be taken into consideration when choosing to place them. Studies have shown that comparable success rates can be achieved with short implants as those with long implants by decreasing the lateral forces to the prosthesis, eliminating cantilevers, increasing implant surface area and improving implant to abutment connection. Short implants can be considered as an effective treatment alternative in resorbed ridges. Short implants can be considered as a viable treatment option in atrophic ridge cases in order to avoid complex surgical procedures required to place long implants. With improvement in the implant surface geometry and surface texture, there is an increase in the bone implant contact area which provides a good primary stability during osseo-integration. PMID:27790598

  3. Thin-film rechargeable lithium batteries for implantable devices

    SciTech Connect

    Bates, J.b.; Dudney, N.J.

    1997-05-01

    Thin films of LiCoO{sub 2} have been synthesized in which the strongest x-ray reflection is either weak or missing, indicating a high degree of preferred orientation. Thin-film solid state batteries with these textured cathode films can deliver practical capacities at high current densities. For example, for one of the cells 70% of the maximum capacity between 4.2 V and 3 V ({approximately}0.2 mAh/cm{sup 2}) was delivered at a current of 2 mA/cm{sup 2}. When cycled at rates of 0.1 mA/cm{sup 2}, the capacity loss was 0.001 %/cycle or less. The reliability and performance of Li-LiCoO{sub 2} thin-film batteries make them attractive for application in implantable devices such as neural stimulators, pacemakers, and defibrillators.

  4. Thin-film Rechargeable Lithium Batteries for Implantable Devices

    DOE R&D Accomplishments Database

    Bates, J. B.; Dudney, N. J.

    1997-05-01

    Thin films of LiCoO{sub 2} have been synthesized in which the strongest x ray reflection is either weak or missing, indicating a high degree of preferred orientation. Thin film solid state batteries with these textured cathode films can deliver practical capacities at high current densities. For example, for one of the cells 70% of the maximum capacity between 4.2 V and 3 V ({approximately}0.2 mAh/cm{sup 2}) was delivered at a current of 2 mA/cm{sup 2}. When cycled at rates of 0.1 mA/cm{sup 2}, the capacity loss was 0.001%/cycle or less. The reliability and performance of Li LiCoO{sub 2} thin film batteries make them attractive for application in implantable devices such as neural stimulators, pacemakers, and defibrillators.

  5. Automatic transmission adapter kit

    SciTech Connect

    Stich, R.L.; Neal, W.D.

    1987-02-10

    This patent describes, in a four-wheel-drive vehicle apparatus having a power train including an automatic transmission and a transfer case, an automatic transmission adapter kit for installation of a replacement automatic transmission of shorter length than an original automatic transmission in the four-wheel-drive vehicle. The adapter kit comprises: an extension housing interposed between the replacement automatic transmission and the transfer case; an output shaft, having a first end which engages the replacement automatic transmission and a second end which engages the transfer case; first sealing means for sealing between the extension housing and the replacement automatic transmission; second sealing means for sealing between the extension housing and the transfer case; and fastening means for connecting the extension housing between the replacement automatic transmission and the transfer case.

  6. Malfunctions of Implantable Cardiac Devices in Patients Receiving Proton Beam Therapy: Incidence and Predictors

    SciTech Connect

    Gomez, Daniel R.; Poenisch, Falk; Pinnix, Chelsea C.; Sheu, Tommy; Chang, Joe Y.; Memon, Nada; Mohan, Radhe; Rozner, Marc A.; Dougherty, Anne H.

    2013-11-01

    Purpose: Photon therapy has been reported to induce resets of implanted cardiac devices, but the clinical sequelae of treating patients with such devices with proton beam therapy (PBT) are not well known. We reviewed the incidence of device malfunctions among patients undergoing PBT. Methods and Materials: From March 2009 through July 2012, 42 patients with implanted cardiac implantable electronic devices (CIED; 28 pacemakers and 14 cardioverter-defibrillators) underwent 42 courses of PBT for thoracic (23, 55%), prostate (15, 36%), liver (3, 7%), or base of skull (1, 2%) tumors at a single institution. The median prescribed dose was 74 Gy (relative biological effectiveness; range 46.8-87.5 Gy), and the median distance from the treatment field to the CIED was 10 cm (range 0.8-40 cm). Maximum proton and neutron doses were estimated for each treatment course. All CIEDs were checked before radiation delivery and monitored throughout treatment. Results: Median estimated peak proton and neutron doses to the CIED in all patients were 0.8 Gy (range 0.13-21 Gy) and 346 Sv (range 11-1100 mSv). Six CIED malfunctions occurred in 5 patients (2 pacemakers and 3 defibrillators). Five of these malfunctions were CIED resets, and 1 patient with a defibrillator (in a patient with a liver tumor) had an elective replacement indicator after therapy that was not influenced by radiation. The mean distance from the proton beam to the CIED among devices that reset was 7.0 cm (range 0.9-8 cm), and the mean maximum neutron dose was 655 mSv (range 330-1100 mSv). All resets occurred in patients receiving thoracic PBT and were corrected without clinical incident. The generator for the defibrillator with the elective replacement indicator message was replaced uneventfully after treatment. Conclusions: The incidence of CIED resets was about 20% among patients receiving PBT to the thorax. We recommend that PBT be avoided in pacing-dependent patients and that patients with any type of CIED receiving

  7. An analysis of implantable cardiac device reliability. The case for improved postmarketing risk assessment and surveillance.

    PubMed

    Laskey, Warren; Awad, Khaled; Lum, Jeremy; Skodacek, Ken; Zimmerman, Barbara; Selzman, Kimberly; Zuckerman, Bram

    2012-07-01

    Implantable cardiac devices have become the mainstay of the treatment of patients with heart disease. However, data regarding their reliability and, inferentially, safety have been called into question. We reviewed annual reports submitted to the Food and Drug Administration Office of Device Evaluation by device manufacturers from 2003 to 2007. The annual number of implantable cardiac defibrillators (ICDs) and cardiac resynchronization therapy defibrillator (CRT-D) implants, explants, and returned devices were tabulated along with the cumulative (Cum) number of implants for each device. We derived an annual explantation rate (AER) defined as the ratio of the annual number of explants less the number of normal battery depletions/Cum (×1000). From 2003 to 2007, 256,392 CRT-D and 459,300 ICD devices were implanted in the United States. The overall mean (±SD) AERs for ICD and CRT-D devices were, respectively, 49.5 (15.6) per 1000 ICD devices and 82.6 (35.5) per 1000 CRT-D devices. The AER for each device type significantly decreased over the study period (P for trend <0.001) although the AER for CRT-D devices was 38% higher than that for ICD devices (P < 0.001). On average, 20.3% of CRT-D devices and 22.6% of ICD devices were returned to the manufacturer for analysis after explantation. The rates of explanted CRT-D and ICD devices decreased from 2003 to 2007. Notwithstanding this favorable trend, the AER for CRT-D devices was higher than that for ICD devices. Improved methods for tracking individual device histories are needed for more precise estimates of the risk of device explantation for suspected malfunction. The proportion of devices returned to the manufacturer is suboptimal and needs to be improved to better understand the mechanisms of device malfunction.

  8. Implanted near-infrared spectroscopy for cardiac monitoring

    NASA Astrophysics Data System (ADS)

    Bhunia, Sourav K.; Cinbis, Can

    2011-02-01

    Implanted Cardioverter Defibrillator (ICD) provides one of the most effective therapies for the prevention of sudden cardiac death, but also delivers some high voltage shocks inappropriately, causing morbidity and mortality. Implanted near-infrared spectroscopy (NIRS) may augment ICD arrhythmia detection by monitoring skeletal muscle perfusion. A two-wavelength, single-distance, continuous-wave implanted NIRS has been evaluated in-vivo. A weighted difference of the changes in attenuation at two wavelengths, across the isobestic point of the hemoglobin spectra, was taken to be the microvascular oxygenation trend indicator (O2 Index). Although the exact weight depends on the local vascular distribution and their oxygen levels, the hypothesis that a constant weight may be adequate for hemodynamic trending during short arrhythmic episodes, was tested. The sensor was implanted subcutaneously both on fresh tissue and inside scar tissue that formed around a pre-existing implant, in 3 animals each. Attenuations were recorded at 660 and 890 nm during normal sinus rhythm (NSR) and induced ventricular fibrillation (VF). The slope of the O2 Index over 10 seconds was computed for 7 NSR and 8 VF episodes in fresh and 13 NSR and 15 VF episodes in scar tissue pockets. The mean O2 Index slope was significantly different (p<0.0001) between NSR and VF rhythms for both the fresh and scar tissue pockets. Therefore implanted NIRS may be useful for preventing inappropriate detection of VF during electromagnetic interference, double counting of ECG T-wave as an R-wave, ICD lead failure, electrocardiographic aberrancy etc.

  9. [Recurrent refractory ventricular fibrillation: how many times is it necessary to defibrillate?].

    PubMed

    Moreno-Millán, E; Castarnado-Calvo, M; Moreno-Cano, S; Pozuelo-Pozuelo, S

    2010-04-01

    Recurrent ventricular fibrillation is that which persists after three consecutive defibrillation attempts. It generally appears in almost 25% of all heart arrests and entails high mortality. Use of amiodarone during resuscitation maneuvers is recommended, this having better results than lidocaine. Neither procainamide nor bretylium should be used in this type of arrhythmia, however beta blockers or magnesium can be used when ischemic heart disease or hypomagnesiemia, respectively, is suspected as the cause. We present the case of a male patient with a background of heart disease (stent in circunflex 8 years earlier) that began with an episode of primary ventricular fibrillation when entering the Emergency Service. He was given 35 shocks of 360 J, without using thoracic compressions at any time since he recovered an effective post-shock pulse with normal neurological condition. Amiodarone and thrombolytics (tenecteplase) were administered during the intervention, achieving favorable resolution after 52 min, once stabilized showing an electrocardiogram of acute coronary syndrome without ST elevation and verifying obstruction of the right coronary artery in the catheterism, on which a stent was placed. He was discharged from the hospital six days after with no neurological sequels. In agreement with the 2005 International Liaison Committee on Resuscitation Recommendations, the resuscitation maneuvers and electrical shocks should be continued while there is a defibrillable rhythm, as occurred in our patient.

  10. Dental Implant Surgery

    MedlinePlus

    Dental implant surgery Overview By Mayo Clinic Staff Dental implant surgery is a procedure that replaces tooth roots with ... look and function much like real ones. Dental implant surgery can offer a welcome alternative to dentures ...

  11. Hip Implant Systems

    MedlinePlus

    ... Devices Products and Medical Procedures Implants and Prosthetics Metal-on-Metal Hip Implants Hip Implants Share Tweet Linkedin Pin ... devices available with different bearing surfaces. These are: Metal-on-Polyethylene: The ball is made of metal ...

  12. Automatic patient respiration failure detection system with wireless transmission

    NASA Technical Reports Server (NTRS)

    Dimeff, J.; Pope, J. M.

    1968-01-01

    Automatic respiration failure detection system detects respiration failure in patients with a surgically implanted tracheostomy tube, and actuates an audible and/or visual alarm. The system incorporates a miniature radio transmitter so that the patient is unencumbered by wires yet can be monitored from a remote location.

  13. Electromagnetic interference of implantable cardiac devices from a shoulder massage machine.

    PubMed

    Yoshida, Saeko; Fujiwara, Kousaku; Kohira, Satoshi; Hirose, Minoru

    2014-09-01

    Shoulder massage machines have two pads that are driven by solenoid coils to perform a per cussive massage on the shoulders. There have been concerns that such machines might create electromagnetic interference (EMI) in implantable cardiac devices because of the time-varying magnetic fields produced by the alternating current in the solenoid coils. The objective of this study was to investigate the potential EMI from one such shoulder massage machine on implantable cardiac devices. We measured the distribution profile of the magnetic field intensity around the massage machine. Furthermore, we performed an inhibition test and an asynchronous test on an implantable cardiac pacemaker using the standardized Irnich human body model. We examined the events on an implantable cardioverter-defibrillator (ICD) using a pacemaker programmer while the massage machine was in operation. The magnetic field distribution profile exhibited a peak intensity of 212 (A/m) in one of the solenoid coils. The maximal interference distance between the massage machine and the implantable cardiac pacemaker was 28 cm. Ventricular fibrillation was induced when the massage machine was brought near the electrode of the ICD and touched the Irnich human body model. It is necessary to provide a "don't use" warning on the box or the exterior of the massage machines or in the user manuals and to caution patients with implanted pacemakers about the dangers and appropriate usage of massage machines.

  14. Cardiac Implantable Electronic Device Safety during Magnetic Resonance Imaging

    PubMed Central

    Hwang, You Mi; Lee, Ji Hyun; Kim, Minsu; Nam, Gi-Byoung; Choi, Kee-Joon; Kim, You-Ho

    2016-01-01

    Background and Objectives Although magnetic resonance imaging (MRI) conditional cardiac implantable electronic devices (CIEDs) have become recently available, non-MRI conditional devices and the presence of epicardial and abandoned leads remain a contraindication for MRIs. Subjects and Methods This was a single center retrospective study, evaluating the clinical outcomes and device parameter changes in patients with CIEDs who underwent an MRI from June 1992 to March 2015. Clinical and device related information was acquired by a thorough chart review. Results A total of 40 patients, 38 with a pacemaker (including epicardially located pacemaker leads) and 2 with implantable cardioverter defibrillators, underwent 50 MRI examinations. Among the patients, 11 had MRI conditional CIEDs, while the remaining had non-MRI conditional devices. Among these patients, 23 patients had traditional contraindications for an MRI: (1) nonfunctional leads (n=1, 2.5%), (2) epicardially located leads (n=9, 22.5%), (3) scanning area in proximity to a device (n=9, 22.5%), (4) devices implanted within 6 weeks (n=2, 5%), and (5) MRI field strength at 3.0 Tesla (n=6, 15%). All patients underwent a satisfactory MRI examination with no adverse events during or after the procedure. There were no significant changes in parameters or malfunctioning devices in any patients with CIEDs. Conclusion Under careful monitoring, MRI is safe to perform on patients with non-MRI conditional CIEDs, remnant leads, and epicardially located leads, as well as MRI-conditional devices. PMID:27826339

  15. [Long term results of patients implanted with CRT-D: Results of a monocentric study].

    PubMed

    Sioua, S; Monsel, F; Attia, C; Elghelbazouri, F; Amara, W

    2015-11-01

    Implantable cardiac defibrillators and resynchronization devices (CRT-D) are frequently used for heart failure patients. This is a retrospective study which included 50 patients with a CRT-D. The objective was to evaluate the prevalence of cardiac events (death, hospitalization for acute heart failure, ventricular arrhythmias). During 30-month follow-up, 4 patients (8%) died, 10 patients were hospitalized for acute decompensated heart failure (20%) and 5 patients (10%) presented an appropriate choc for a ventricular arrhythmia. In total, 19 patients presented at least one cardiac event (38%). An improvement in dyspnea was reported in 84% of patients. An improvement of left ventricular ejection fraction (LVEF) was reported in 74% of patients and 12% of them have normalized LVEF. In this study, the majority of patients implanted with a CRT-D presented an improvement of their symptoms. However, residual cardiac events were reported and remain unpredictable.

  16. Safe and Simplified Salvage Technique for Exposed Implantable Cardiac Electronic Devices under Local Anesthesia

    PubMed Central

    Jung, Chang Young; Kim, Sung-Eun

    2017-01-01

    Background Skin erosion is a dire complication of implantable cardiac pacemakers and defibrillators. Classical treatments involve removal of the entire generator and lead systems, however, these may result in fatal complications. In this study, we present our experience with a simplified salvage technique for exposed implantable cardiac electronic devices (ICEDs) without removing the implanted device, in an attempt to reduce the risks and complication rates associated with this condition. Methods The records of 10 patients who experienced direct ICED exposure between January 2012 and December 2015 were retrospectively reviewed. The following surgical procedure was performed in all patients: removal of skin erosion and capsule, creation of a new pocket at least 1.0–1.5 cm inferior to its original position, migration of the ICED to the new pocket, and insertion of closed-suction drainage. Patients with gross local sepsis or septicemia were excluded from this study. Results Seven patients had cardiac pacemakers and the other 3 had implantable cardiac defibrillators. The time from primary ICED placement to exposure ranged from 0.3 to 151 months (mean, 29 months. Postoperative follow-up in this series ranged from 8 to 31 months (mean follow-up, 22 months). Among the 10 patients, none presented with any signs of overt infection or cutaneous lesions, except 1 patient with hematoma on postoperative day 5. The hematoma was successfully treated by surgical removal and repositioning of the closed-suction drainage. Conclusions Based on our experience, salvage of exposed ICEDs is possible without removing the device in selected patients. PMID:28194346

  17. Health Care Utilization and Expenditures Associated With Remote Monitoring in Patients With Implantable Cardiac Devices.

    PubMed

    Ladapo, Joseph A; Turakhia, Mintu P; Ryan, Michael P; Mollenkopf, Sarah A; Reynolds, Matthew R

    2016-05-01

    Several randomized trials and decision analysis models have found that remote monitoring may reduce health care utilization and expenditures in patients with cardiac implantable electronic devices (CIEDs), compared with in-office monitoring. However, little is known about the generalizability of these findings to unselected populations in clinical practice. To compare health care utilization and expenditures associated with remote monitoring and in-office monitoring in patients with CIEDs, we used Truven Health MarketScan Commercial Claims and Medicare Supplemental Databases. We selected patients newly implanted with an implantable cardioverter defibrillators (ICD), cardiac resynchronization therapy defibrillator (CRT-D), or permanent pacemaker (PPM), in 2009, who had continuous health plan enrollment 2 years after implantation. Generalized linear models and propensity score matching were used to adjust for confounders and estimate differences in health care utilization and expenditures in patients with remote or in-office monitoring. We identified 1,127; 427; and 1,295 pairs of patients with a similar propensity for receiving an ICD, CRT-D, or PPM, respectively. Remotely monitored patients with ICDs experienced fewer emergency department visits resulting in discharge (p = 0.050). Remote monitoring was associated with lower health care expenditures in office visits among patients with PPMs (p = 0.025) and CRT-Ds (p = 0.006) and lower total inpatient and outpatient expenditures in patients with ICDs (p <0.0001). In conclusion, remote monitoring of patients with CIEDs may be associated with reductions in health care utilization and expenditures compared with exclusive in-office care.

  18. Automatic differentiation bibliography

    SciTech Connect

    Corliss, G.F.

    1992-07-01

    This is a bibliography of work related to automatic differentiation. Automatic differentiation is a technique for the fast, accurate propagation of derivative values using the chain rule. It is neither symbolic nor numeric. Automatic differentiation is a fundamental tool for scientific computation, with applications in optimization, nonlinear equations, nonlinear least squares approximation, stiff ordinary differential equation, partial differential equations, continuation methods, and sensitivity analysis. This report is an updated version of the bibliography which originally appeared in Automatic Differentiation of Algorithms: Theory, Implementation, and Application.

  19. Wireless microsensor network solutions for neurological implantable devices

    NASA Astrophysics Data System (ADS)

    Abraham, Jose K.; Whitchurch, Ashwin; Varadan, Vijay K.

    2005-05-01

    trigger the feed back system or contact a point-of-care office that can remotely control the implantable system. The remote monitoring technology can be adaptable to EEG monitoring of children with epilepsy, implantable cardioverters/defibrillators, pacemakers, chronic pain management systems, treatment for sleep disorders, patients with implantable devices for diabetes. In addition, the development of a wireless neural electronics interface to detect, transmit and analyze neural signals could help patients with spinal injuries to regain some semblance of mobile activity.

  20. [Bilateral cochlear implantation].

    PubMed

    Kronenberg, Jona; Migirov, Lela; Taitelbaum-Swead, Rikey; Hildesheimer, Minka

    2010-06-01

    Cochlear implant surgery became the standard of care in hearing rehabilitation of patients with severe to profound sensorineural hearing loss. This procedure may alter the lives of children and adults enabling them to integrate with the hearing population. In the past, implantation was performed only in one ear, despite the fact that binaural hearing is superior to unilateral, especially in noisy conditions. Cochlear implantation may be performed sequentially or simultaneously. The "sensitive period" of time between hearing loss and implantation and between the two implantations, when performed sequentially, significantly influences the results. Shorter time spans between implantations improve the hearing results after implantation. Hearing success after implantation is highly dependent on the rehabilitation process which includes mapping, implant adjustments and hearing training. Bilateral cochlear implantation in children is recommended as the proposed procedure in spite of the additional financial burden.

  1. Cardiac Resynchronization Therapy Defibrillator Treatment in a Child with Heart Failure and Ventricular Arrhythmia

    PubMed Central

    Kim, Hak Ju; Cho, Sungkyu; Kim, Woong-Han

    2016-01-01

    Cardiac resynchronization therapy (CRT) is a new treatment for refractory heart failure. However, most patients with heart failure treated with CRT are adults, middle-aged or older with idiopathic or ischemic dilated cardiomyopathy. We treated a 12-year-old boy, who was transferred after cardiac arrest, with dilated cardiomyopathy, left bundle-branch block, and ventricular tachycardia. We performed cardiac resynchronization therapy with a defibrillator (CRT-D). After CRT-D, left ventricular ejection fraction improved from 22% to 44% assessed by echocardiogram 1 year postoperatively. On electrocardiogram, QRS duration was shortened from 206 to 144 ms. The patient’s clinical symptoms also improved. For pediatric patients with refractory heart failure and ventricular arrhythmia, CRT-D could be indicated as an effective therapeutic option. PMID:27525239

  2. PDE constrained optimization of electrical defibrillation in a 3D ventricular slice geometry.

    PubMed

    Chamakuri, Nagaiah; Kunisch, Karl; Plank, Gernot

    2016-04-01

    A computational study of an optimal control approach for cardiac defibrillation in a 3D geometry is presented. The cardiac bioelectric activity at the tissue and bath volumes is modeled by the bidomain model equations. The model includes intramural fiber rotation, axially symmetric around the fiber direction, and anisotropic conductivity coefficients, which are extracted from a histological image. The dynamics of the ionic currents are based on the regularized Mitchell-Schaeffer model. The controls enter in the form of electrodes, which are placed at the boundary of the bath volume with the goal of dampening undesired arrhythmias. The numerical optimization is based on Newton techniques. We demonstrated the parallel architecture environment for the computation of potentials on multidomains and for the higher order optimization techniques.

  3. Design of an ultrahigh-energy hydrogen thyratron/SCR research defibrillator.

    PubMed

    Schuder, J C; Gold, J H

    1976-01-01

    The design features of an ultrahigh-energy research defibrillator are described. Three voltage sources are used. The first is a 60-Hz supply of adjustable amplitude and duration for inducing fibrillation. The second source uses an 18.000-joule capacitor bank which can be charged to 800, 1600, or 2400 volts. SCRs in series with the chest are used to initiate the discharge, and SCRs shunting the capacitor bank terminate the discharge. The third source employs another 18,000-joule capacitor bank which can be charged to 5000, 10,000 or 15,000 volts. In this source, large ceramic-enveloped hydrogen thyratrons are used for both initiating and terminating the discharge. In the second and third sources, which can deliver rectangular, trapezoidal, truncated exponential, or untruncated exponential waveforms, capacitor charge time is 10 sec and the duration of the delivered shock is continuously adjustable from 100 musec through 1 sec.

  4. Irregularity test for very short electrocardiogram (ECG) signals as a method for predicting a successful defibrillation in patients with ventricular fibrillation.

    PubMed

    Jagric, Timotej; Marhl, Marko; Stajer, Dusan; Kocjancic, Spela Tadel; Jagric, Tomaz; Podbregar, Matej; Perc, Matjaz

    2007-03-01

    A significant proportion of patients with ventricular fibrillation (VF) can only be defibrillated after a period of chest compressions and ventilation before the defibrillation attempt. In these patients, unsuccessful defibrillations increase the duration of heart arrest and reduce the possibility of a successful resuscitation, which could be avoided if a reliable prediction for the success of defibrillation could be made. A new method is presented for estimating the irregularity in very short electrocardiographic (ECG) recordings that enables the prediction of a successful defibrillation in patients with VF. This method is based on a recently developed determinism test for very short time series. A slight modification shows that the method can be used to determine relative differences in irregularity of the studied signals. In particular, ECG recordings of VF from patients who could be successfully defibrillated are characterized by a higher level of irregularity, indicating a chaotic nature of the dynamics of the heart, which is in agreement with previous studies on long ECG recordings showing that cardiac chaos was prevalent in healthy heart, whereas in severe congestive heart failure, a decrease in the chaotic behavior was observed.

  5. Automatic Versus Manual Indexing

    ERIC Educational Resources Information Center

    Vander Meulen, W. A.; Janssen, P. J. F. C.

    1977-01-01

    A comparative evaluation of results in terms of recall and precision from queries submitted to systems with automatic and manual subject indexing. Differences were attributed to query formulation. The effectiveness of automatic indexing was found equivalent to manual indexing. (Author/KP)

  6. Automatic Differentiation Package

    SciTech Connect

    Gay, David M.; Phipps, Eric; Bratlett, Roscoe

    2007-03-01

    Sacado is an automatic differentiation package for C++ codes using operator overloading and C++ templating. Sacado provide forward, reverse, and Taylor polynomial automatic differentiation classes and utilities for incorporating these classes into C++ codes. Users can compute derivatives of computations arising in engineering and scientific applications, including nonlinear equation solving, time integration, sensitivity analysis, stability analysis, optimization and uncertainity quantification.

  7. Automatic Test Program Generation.

    DTIC Science & Technology

    1978-03-01

    presents a test description language, NOPAL , in which a user may describe diagnostic tests, and a software system which automatically generates test...programs for an automatic test equipment based on the descriptions of tests. The software system accepts as input the tests specified in NOPAL , performs

  8. Digital automatic gain control

    NASA Technical Reports Server (NTRS)

    Uzdy, Z.

    1980-01-01

    Performance analysis, used to evaluated fitness of several circuits to digital automatic gain control (AGC), indicates that digital integrator employing coherent amplitude detector (CAD) is best device suited for application. Circuit reduces gain error to half that of conventional analog AGC while making it possible to automatically modify response of receiver to match incoming signal conditions.

  9. Computer-aided recognition of dental implants in X-ray images

    NASA Astrophysics Data System (ADS)

    Morais, Pedro; Queirós, Sandro; Moreira, António H. J.; Ferreira, Adriano; Ferreira, Ernesto; Duque, Duarte; Rodrigues, Nuno F.; Vilaça, João. L.

    2015-03-01

    Dental implant recognition in patients without available records is a time-consuming and not straightforward task. The traditional method is a complete user-dependent process, where the expert compares a 2D X-ray image of the dental implant with a generic database. Due to the high number of implants available and the similarity between them, automatic/semi-automatic frameworks to aide implant model detection are essential. In this study, a novel computer-aided framework for dental implant recognition is suggested. The proposed method relies on image processing concepts, namely: (i) a segmentation strategy for semi-automatic implant delineation; and (ii) a machine learning approach for implant model recognition. Although the segmentation technique is the main focus of the current study, preliminary details of the machine learning approach are also reported. Two different scenarios are used to validate the framework: (1) comparison of the semi-automatic contours against implant's manual contours of 125 X-ray images; and (2) classification of 11 known implants using a large reference database of 601 implants. Regarding experiment 1, 0.97±0.01, 2.24±0.85 pixels and 11.12±6 pixels of dice metric, mean absolute distance and Hausdorff distance were obtained, respectively. In experiment 2, 91% of the implants were successfully recognized while reducing the reference database to 5% of its original size. Overall, the segmentation technique achieved accurate implant contours. Although the preliminary classification results prove the concept of the current work, more features and an extended database should be used in a future work.

  10. Automatic wire twister.

    PubMed

    Smith, J F; Rodeheaver, G T; Thacker, J G; Morgan, R F; Chang, D E; Fariss, B L; Edlich, R F

    1988-06-01

    This automatic wire twister used in surgery consists of a 6-inch needle holder attached to a twisting mechanism. The major advantage of this device is that it twists wires significantly more rapidly than the conventional manual techniques. Testing has found that the ultimate force required to disrupt the wires twisted by either the automatic wire twister or manual techniques did not differ significantly and was directly related to the number of twists. The automatic wire twister reduces the time needed for wire twisting without altering the security of the twisted wire.

  11. Using a Combined Platform of Swarm Intelligence Algorithms and GIS to Provide Land Suitability Maps for Locating Cardiac Rehabilitation Defibrillators

    PubMed Central

    KAFFASH-CHARANDABI, Neda; SADEGHI-NIARAKI, Abolghasem; PARK, Dong-Kyun

    2015-01-01

    Background: Cardiac arrest is a condition in which the heart is completely stopped and is not pumping any blood. Although most cardiac arrest cases are reported from homes or hospitals, about 20% occur in public areas. Therefore, these areas need to be investigated in terms of cardiac arrest incidence so that places of high incidence can be identified and cardiac rehabilitation defibrillators installed there. Methods: In order to investigate a study area in Petersburg, Pennsylvania State, and to determine appropriate places for installing defibrillators with 5-year period data, swarm intelligence algorithms were used. Moreover, the location of the defibrillators was determined based on the following five evaluation criteria: land use, altitude of the area, economic conditions, distance from hospitals and approximate areas of reported cases of cardiac arrest for public places that were created in geospatial information system (GIS). Results: The A-P HADEL algorithm results were more precise about 27.36%. The validation results indicated a wider coverage of real values and the verification results confirmed the faster and more exact optimization of the cost function in the PSO method. Conclusion: The study findings emphasize the necessity of applying optimal optimization methods along with GIS and precise selection of criteria in the selection of optimal locations for installing medical facilities because the selected algorithm and criteria dramatically affect the final responses. Meanwhile, providing land suitability maps for installing facilities across hot and risky spots has the potential to save many lives. PMID:26587471

  12. [Biomaterials in cochlear implants].

    PubMed

    Stöver, T; Lenarz, T

    2009-05-01

    Cochlear implants (CI) represent the "gold standard" for the treatment of congenitally deaf children and postlingually deafened adults. Thus, cochlear implantation is a success story of new bionic prosthesis development. Owing to routine application of cochlear implants in adults but also in very young children (below the age of one), high demands are placed on the implants. This is especially true for biocompatibility aspects of surface materials of implant parts which are in contact with the human body. In addition, there are various mechanical requirements which certain components of the implants must fulfil, such as flexibility of the electrode array and mechanical resistance of the implant housing. Due to the close contact of the implant to the middle ear mucosa and because the electrode array is positioned in the perilymphatic space via cochleostomy, there is a potential risk of bacterial transferral along the electrode array into the cochlea. Various requirements that have to be fulfilled by cochlear implants, such as biocompatibility, electrode micromechanics, and although a very high level of technical standards has been carried out there is still demand for the improvement of implants as well as of the materials used for manufacturing, ultimately leading to increased implant performance. General considerations of material aspects related to cochlear implants as well as potential future perspectives of implant development will be discussed.

  13. Endoscopic Electrosurgery in Patients with Cardiac Implantable Electronic Devices

    PubMed Central

    Baeg, Myong Ki; Kim, Sang-Woo; Ko, Sun-Hye; Lee, Yoon Bum; Hwang, Seawon; Lee, Bong-Woo; Choi, Hye Jin; Park, Jae Myung; Lee, In-Seok; Oh, Yong-Seog; Choi, Myung-Gyu

    2016-01-01

    Background/Aims: Patients with cardiac implantable electronic devices (CIEDs) undergoing endoscopic electrosurgery (EE) are at a risk of electromagnetic interference (EMI). We aimed to analyze the effects of EE in CIED patients. Methods: Patients with CIED who underwent EE procedures such as snare polypectomy, endoscopic submucosal dissection (ESD), and endoscopic retrograde cholangiopancreatography (ERCP) with endoscopic sphincterotomy (EST) were retrospectively analyzed. Postprocedural symptoms as well as demographic and outpatient follow-up data were reviewed through medical records. Electrical data, including preprocedural and postprocedural arrhythmia records, were reviewed through pacemaker interrogation, 24-hour Holter monitoring, or electrocardiogram. Results: Fifty-nine procedures in 49 patients were analyzed. Fifty procedures were performed in 43 patients with a pacemaker, and nine were performed in six patients with an implantable cardioverter-defibrillator. There were one gastric and 44 colon snare polypectomies, five gastric and one colon ESDs, and eight ERCPs with EST. Fifty-five cases of electrical follow-up were noted, with two postprocedural changes not caused by EE. Thirty-one pacemaker interrogations had procedure recordings, with two cases of asymptomatic tachycardia. All patients were asymptomatic with no adverse events. Conclusions: Our study reports no adverse events from EE in patients with CIED, suggesting that this procedure is safe. However, because of the possibility of EMI, recommendations on EE should be followed. PMID:26867552

  14. Central nervous system MRI and cardiac implantable electronic devices.

    PubMed

    Cadieu, Romain; Peron, Marilyne; Le Ven, Florent; Kerdraon, Sébastien; Boutet, Claire; Mansourati, Jacques; Ben Salem, Douraied

    2017-02-01

    As the population ages and indications for MRI increase, it is estimated that 50 to 75% of patients with a cardiac implantable electronic device (CIED) - pacemaker (PM) or implanted cardiac defibrillator (ICD) - will need an MRI during their CIED's lifetime. Three categories of materials are defined: MRI compatible, MRI non-compatible, and MRI conditional. MRI compatible CIEDs without electrodes have been developed, but do not allow battery changes, so that they are exclusively indicated for patients whose life expectancy is less than that of the battery (6-7years). For MRI conditional CIEDs, all manufacturers publish restrictions. These restrictions can relate to the patient (size, position in the MRI, body temperature), the MRI parameters (magnetic field), or the examination in itself (gradients, specific absorption rate, duration, isocenter). The neuroradiologist can expect to be confronted with the issue of MRI in patients with a CIED. The purpose of this review is to provide them with updated information on MRI and CIEDs.

  15. Breast Implants: Saline vs. Silicone

    MedlinePlus

    ... to women of any age for breast reconstruction. Silicone breast implants Silicone implants are pre-filled with ... likely be inserted at the same time. Ruptured silicone implant If a silicone breast implant ruptures, you ...

  16. Implants for lucky few

    NASA Astrophysics Data System (ADS)

    Brandon, David

    2011-08-01

    In his article "Vision of beauty" (May pp22-27), Richard Taylor points the way to fractal design for retinal implants and makes an enthusiastic case for incorporating such features into the next generation of such implants.

  17. Automatic switching matrix

    DOEpatents

    Schlecht, Martin F.; Kassakian, John G.; Caloggero, Anthony J.; Rhodes, Bruce; Otten, David; Rasmussen, Neil

    1982-01-01

    An automatic switching matrix that includes an apertured matrix board containing a matrix of wires that can be interconnected at each aperture. Each aperture has associated therewith a conductive pin which, when fully inserted into the associated aperture, effects electrical connection between the wires within that particular aperture. Means is provided for automatically inserting the pins in a determined pattern and for removing all the pins to permit other interconnecting patterns.

  18. Detection of atrial arrhythmia for cardiac rhythm management by implantable devices.

    PubMed

    Morris, M M; KenKnight, B H; Lang, D J

    2000-01-01

    Implantable atrial defibrillators (IAD) should provide pacing therapy whenever appropriate (ie, typical atrial flutter) to minimize shock-related patient discomfort. Additionally, IADs should provide diagnostics regarding atrial arrhythmia type and frequency of occurrence to enable improved physician management of atrial arrhythmia. To achieve this, IADs should accurately classify atrial arrhythmia such as atrial fibrillation (AF) and atrial flutter (AFL) This article evaluates the performance of an algorithm, atrial rhythm classification (ARC), designed to classify AF and AFL. The ARC algorithm uses maximum rate, standard deviation, and range of the 12 most recent atrial cycle lengths to plot a point in a three-dimensional space. A decision boundary divides the space into 2 regions--faster/unstable atrial cycle lengths (AF) or slower/stable cycle lengths (AFL). Classifications are made on a sliding window of 12 consecutive cycles until the end of the episode is reached. In this way, continuous episode feedback is provided that can be used to help guide device therapy, measure arrhythmia type and frequency of occurrence. Bipolar (1-cm) electrogram episodes of AF (n = 16) and AFL (n = 7) were acquired from 20 patients and retrospectively analyzed using the ARC algorithm. The sensitivity and specificity in this study was 0.993 and 0.982, respectively. The ARC algorithm would have appropriately guided atrial therapy and minimized discomfort associated with defibrillation shocks in this small patient data set warranting further studies. The ARC algorithm may also be beneficial as a diagnostic tool to assist physician management of atrial arrhythmia.

  19. Candida and cardiovascular implantable electronic devices: a case of lead and native aortic valve endocarditis and literature review.

    PubMed

    Glavis-Bloom, Justin; Vasher, Scott; Marmor, Meghan; Fine, Antonella B; Chan, Philip A; Tashima, Karen T; Lonks, John R; Kojic, Erna M

    2015-11-01

    Use of cardiovascular implantable electronic devices (CIED), including permanent pacemakers (PPM) and implantable cardioverter defibrillators (ICD), has increased dramatically over the past two decades. Most CIED infections are caused by staphylococci. Fungal causes are rare and their prognosis is poor. To our knowledge, there has not been a previously reported case of multifocal Candida endocarditis involving both a native left-sided heart valve and a CIED lead. Here, we report the case of a 70-year-old patient who presented with nausea, vomiting, and generalised fatigue, and was found to have Candida glabrata endocarditis involving both a native aortic valve and right atrial ICD lead. We review the literature and summarise four additional cases of CIED-associated Candida endocarditis published from 2009 to 2014, updating a previously published review of cases prior to 2009. We additionally review treatment guidelines and discuss management of CIED-associated Candida endocarditis.

  20. Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands

    NASA Astrophysics Data System (ADS)

    Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

    2016-06-01

    The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich’s flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs.

  1. Trends in Cochlear Implants

    PubMed Central

    Zeng, Fan-Gang

    2004-01-01

    More than 60,000 people worldwide use cochlear implants as a means to restore functional hearing. Although individual performance variability is still high, an average implant user can talk on the phone in a quiet environment. Cochlear-implant research has also matured as a field, as evidenced by the exponential growth in both the patient population and scientific publication. The present report examines current issues related to audiologic, clinical, engineering, anatomic, and physiologic aspects of cochlear implants, focusing on their psychophysical, speech, music, and cognitive performance. This report also forecasts clinical and research trends related to presurgical evaluation, fitting protocols, signal processing, and postsurgical rehabilitation in cochlear implants. Finally, a future landscape in amplification is presented that requires a unique, yet complementary, contribution from hearing aids, middle ear implants, and cochlear implants to achieve a total solution to the entire spectrum of hearing loss treatment and management. PMID:15247993

  2. Reliability of old and new ventricular fibrillation detection algorithms for automated external defibrillators

    PubMed Central

    Amann, Anton; Tratnig, Robert; Unterkofler, Karl

    2005-01-01

    Background A pivotal component in automated external defibrillators (AEDs) is the detection of ventricular fibrillation by means of appropriate detection algorithms. In scientific literature there exists a wide variety of methods and ideas for handling this task. These algorithms should have a high detection quality, be easily implementable, and work in real time in an AED. Testing of these algorithms should be done by using a large amount of annotated data under equal conditions. Methods For our investigation we simulated a continuous analysis by selecting the data in steps of one second without any preselection. We used the complete BIH-MIT arrhythmia database, the CU database, and the files 7001 – 8210 of the AHA database. All algorithms were tested under equal conditions. Results For 5 well-known standard and 5 new ventricular fibrillation detection algorithms we calculated the sensitivity, specificity, and the area under their receiver operating characteristic. In addition, two QRS detection algorithms were included. These results are based on approximately 330 000 decisions (per algorithm). Conclusion Our values for sensitivity and specificity differ from earlier investigations since we used no preselection. The best algorithm is a new one, presented here for the first time. PMID:16253134

  3. Employment and residential characteristics in relation to automated external defibrillator locations

    PubMed Central

    Griffis, Heather M.; Band, Roger A; Ruther, Matthew; Harhay, Michael; Asch, David A.; Hershey, John C.; Hill, Shawndra; Nadkarni, Lindsay; Kilaru, Austin; Branas, Charles C.; Shofer, Frances; Nichol, Graham; Becker, Lance B.; Merchant, Raina M.

    2015-01-01

    Background Survival from out-of-hospital cardiac arrest (OHCA) is generally poor and varies by geography. Variability in automated external defibrillator (AED) locations may be a contributing factor. To inform optimal placement of AEDs, we investigated AED access in a major US city relative to demographic and employment characteristics. Methods and Results This was a retrospective analysis of a Philadelphia AED registry (2,559 total AEDs). The 2010 US Census and the Local Employment Dynamics (LED) database by ZIP code was used. AED access was calculated as the weighted areal percentage of each ZIP code covered by a 400 meter radius around each AED. Of 47 ZIP codes, only 9%(4) were high AED service areas. In 26%(12) of ZIP codes, less than 35% of the area was covered by AED service areas. Higher AED access ZIP codes were more likely to have a moderately populated residential area (p=0.032), higher median household income (p=0.006), and higher paying jobs (p=008). Conclusions The locations of AEDs vary across specific ZIP codes; select residential and employment characteristics explain some variation. Further work on evaluating OHCA locations, AED use and availability, and OHCA outcomes could inform AED placement policies. Optimizing the placement of AEDs through this work may help to increase survival. PMID:26856232

  4. Cardiac device implantation in Fabry disease: A retrospective monocentric study.

    PubMed

    Sené, Thomas; Lidove, Olivier; Sebbah, Joel; Darondel, Jean-Marc; Picard, Hervé; Aaron, Laurent; Fain, Olivier; Zenone, Thierry; Joly, Dominique; Charron, Philippe; Ziza, Jean-Marc

    2016-10-01

    The incidence and predictive factors of arrhythmias and/or conduction abnormalities (ACAs) requiring cardiac device (CD) implantation are poorly characterized in Fabry disease (FD). The aim of our retrospective study was to determine the prevalence, incidence, and factors associated with ACA requiring CD implantation in a monocentric cohort of patients with confirmed FD who were followed up in a department of internal medicine and reference center for FD.Forty-nine patients (20M, 29F) were included. Nine patients (4M, 5F; 18%) had at least one episode of ACA leading to device therapy. Six patients (4M/2F) required a pacemaker (PM) for sinus node dysfunction (n = 4) or atrioventricular disease (n = 2). One female patient required an internal cardioverter-defibrillator (ICD) to prevent sudden cardiac death because of nonsustained ventricular tachycardia (nSVT). One female patient required PM-ICD for sinus node dysfunction and nSVT. One patient underwent CD implantation before the diagnosis of FD. The annual rate of CD implantation was estimated at 1.90 per 100 person years. On univariate analysis at the end of the follow-up period, the factors associated with ACAs requiring CD implantation were as follows: delayed diagnosis of FD, delayed initiation of enzyme replacement therapy, age at the last follow-up visit, and severe multiorgan phenotype (hypertrophic cardiomyopathy, chronic kidney disease, and/or sensorineural hearing loss). On multivariate analysis, age at diagnosis of FD and age at the last follow-up visit were independently associated with an increased risk of ACAs requiring CD (P < 0.05).Considering the high frequency of ACAs requiring CD implantation and the risk of sudden death in patients with FD, regular monitoring is mandatory, especially in patients with a late diagnosis of FD and/or with a severe phenotype. Regular Holter ECGs, therapeutic education of patients, and deliverance of an emergency card including a phenotype summary are

  5. WOLF; automatic typing program

    USGS Publications Warehouse

    Evenden, G.I.

    1982-01-01

    A FORTRAN IV program for the Hewlett-Packard 1000 series computer provides for automatic typing operations and can, when employed with manufacturer's text editor, provide a system to greatly facilitate preparation of reports, letters and other text. The input text and imbedded control data can perform nearly all of the functions of a typist. A few of the features available are centering, titles, footnotes, indentation, page numbering (including Roman numerals), automatic paragraphing, and two forms of tab operations. This documentation contains both user and technical description of the program.

  6. AUTOMATIC COUNTING APPARATUS

    DOEpatents

    Howell, W.D.

    1957-08-20

    An apparatus for automatically recording the results of counting operations on trains of electrical pulses is described. The disadvantages of prior devices utilizing the two common methods of obtaining the count rate are overcome by this apparatus; in the case of time controlled operation, the disclosed system automatically records amy information stored by the scaler but not transferred to the printer at the end of the predetermined time controlled operations and, in the case of count controlled operation, provision is made to prevent a weak sample from occupying the apparatus for an excessively long period of time.

  7. Skill acquisition and retention in automated external defibrillator (AED) use and CPR by lay responders: a prospective study.

    PubMed

    Woollard, Malcolm; Whitfeild, Richard; Smith, Anna; Colquhoun, Michael; Newcombe, Robert G; Vetteer, Norman; Chamberlain, Douglas

    2004-01-01

    This prospective study evaluated the acquisition and retention of skills in cardio-pulmonary resuscitation (CPR) and the use of the automated external defibrillator (AED) by lay volunteers involved in the Department of Health, England National Defibrillator Programme. One hundred and twelve trainees were tested immediately before and after and initial 4-h class; 76 were similarly reassessed at refresher training 6 months later. A standardised test scenario that required assessment of the casualty, CPR and the use of on AED was evaluated using recording manikin data and video recordings. Before training only 44% of subjects delivered a shock. Afterwards, all did so and the average delay to first shock was reduced by 57 s. All trainees placed the defibrillator electrodes in an "acceptable" position after training, but very few did so in the recommended "ideal" position. After refresher training 80% of subjects used the correct sequence for CPR and shock delivery, yet a third failed to perform adequate safety checks before all shocks. The trainees self-assessed AED competence score was 86 (scale 0-100) after the initial class and their confidence that they would act in a real emergency was rated at a similar level. Initial training improved performance of all CPR skills, although all except compression rate had deteriorated after 6 months. The proportion of subjects able to correctly perform most CPR skill was higher following refresher training that after the initial class. Although this course was judged to be effective in teaching delivery of counter-shocks, the need was identified for more emphasis on positioning of electrodes, pre-shock safety checks, airway opening, ventilation volume, checking for signs of a circulation, hand positioning, and depth and rate of chest compressions.

  8. [Cochlear implant in adults].

    PubMed

    Bouccara, D; Mosnier, I; Bernardeschi, D; Ferrary, E; Sterkers, O

    2012-03-01

    Cochlear implant in adults is a procedure, dedicated to rehabilitate severe to profound hearing loss. Because of technological progresses and their applications for signal strategies, new devices can improve hearing, even in noise conditions. Binaural stimulation, cochlear implant and hearing aid or bilateral cochlear implants are the best opportunities to access to better level of comprehension in all conditions and space localisation. By now minimally invasive surgery is possible to preserve residual hearing and use a double stimulation modality for the same ear: electrical for high frequencies and acoustic for low frequencies. In several conditions, cochlear implant is not possible due to cochlear nerve tumour or major malformations of the inner ear. In these cases, a brainstem implantation can be considered. Clinical data demonstrate that improvement in daily communication, for both cochlear and brainstem implants, is correlated with cerebral activation of auditory cortex.

  9. Automaticity of Conceptual Magnitude.

    PubMed

    Gliksman, Yarden; Itamar, Shai; Leibovich, Tali; Melman, Yonatan; Henik, Avishai

    2016-02-16

    What is bigger, an elephant or a mouse? This question can be answered without seeing the two animals, since these objects elicit conceptual magnitude. How is an object's conceptual magnitude processed? It was suggested that conceptual magnitude is automatically processed; namely, irrelevant conceptual magnitude can affect performance when comparing physical magnitudes. The current study further examined this question and aimed to expand the understanding of automaticity of conceptual magnitude. Two different objects were presented and participants were asked to decide which object was larger on the screen (physical magnitude) or in the real world (conceptual magnitude), in separate blocks. By creating congruent (the conceptually larger object was physically larger) and incongruent (the conceptually larger object was physically smaller) pairs of stimuli it was possible to examine the automatic processing of each magnitude. A significant congruity effect was found for both magnitudes. Furthermore, quartile analysis revealed that the congruity was affected similarly by processing time for both magnitudes. These results suggest that the processing of conceptual and physical magnitudes is automatic to the same extent. The results support recent theories suggested that different types of magnitude processing and representation share the same core system.

  10. Automatic Program Synthesis Reports.

    ERIC Educational Resources Information Center

    Biermann, A. W.; And Others

    Some of the major results of future goals of an automatic program synthesis project are described in the two papers that comprise this document. The first paper gives a detailed algorithm for synthesizing a computer program from a trace of its behavior. Since the algorithm involves a search, the length of time required to do the synthesis of…

  11. Automatic Language Identification

    DTIC Science & Technology

    2000-08-01

    the speech utterance is hypothesized. ter performance for his HMM approach than his static ap- Finally, Thyme -Gobbel et al. [47] have also looked...1998. [47] A.E. Thyme -Gobbel and S.E. Hutchins. On using prosodic cues in automatic language identification. In International Conference on Spoken

  12. Automatic multiple applicator electrophoresis

    NASA Technical Reports Server (NTRS)

    Grunbaum, B. W.

    1977-01-01

    Easy-to-use, economical device permits electrophoresis on all known supporting media. System includes automatic multiple-sample applicator, sample holder, and electrophoresis apparatus. System has potential applicability to fields of taxonomy, immunology, and genetics. Apparatus is also used for electrofocusing.

  13. Automatic Transmission Vehicle Injuries

    PubMed Central

    Fidler, Malcolm

    1973-01-01

    Four drivers sustained severe injuries when run down by their own automatic cars while adjusting the carburettor or throttle linkages. The transmission had been left in the “Drive” position and the engine was idling. This accident is easily avoidable. PMID:4695693

  14. Automaticity of Conceptual Magnitude

    PubMed Central

    Gliksman, Yarden; Itamar, Shai; Leibovich, Tali; Melman, Yonatan; Henik, Avishai

    2016-01-01

    What is bigger, an elephant or a mouse? This question can be answered without seeing the two animals, since these objects elicit conceptual magnitude. How is an object’s conceptual magnitude processed? It was suggested that conceptual magnitude is automatically processed; namely, irrelevant conceptual magnitude can affect performance when comparing physical magnitudes. The current study further examined this question and aimed to expand the understanding of automaticity of conceptual magnitude. Two different objects were presented and participants were asked to decide which object was larger on the screen (physical magnitude) or in the real world (conceptual magnitude), in separate blocks. By creating congruent (the conceptually larger object was physically larger) and incongruent (the conceptually larger object was physically smaller) pairs of stimuli it was possible to examine the automatic processing of each magnitude. A significant congruity effect was found for both magnitudes. Furthermore, quartile analysis revealed that the congruity was affected similarly by processing time for both magnitudes. These results suggest that the processing of conceptual and physical magnitudes is automatic to the same extent. The results support recent theories suggested that different types of magnitude processing and representation share the same core system. PMID:26879153

  15. Reactor component automatic grapple

    DOEpatents

    Greenaway, Paul R.

    1982-01-01

    A grapple for handling nuclear reactor components in a medium such as liquid sodium which, upon proper seating and alignment of the grapple with the component as sensed by a mechanical logic integral to the grapple, automatically seizes the component. The mechanical logic system also precludes seizure in the absence of proper seating and alignment.

  16. Implant treatment planning considerations.

    PubMed

    Kao, Richard T

    2008-04-01

    As dental implants become a more accepted treatment modality, there is a need for all parties involved with implant dentistry to be familiar with various treatment planning issues. Though the success can be highly rewarding, failure to forecast treatment planning issues can result in an increase of surgical needs, surgical cost, and even case failure. In this issue, the focus is on implant treatment planning considerations.

  17. Osseointegrated implant prosthodontics.

    PubMed

    Rogoff, G S

    1992-06-01

    This review covers recent literature on prosthodontic aspects of osseointegrated implants. Long-term prognosis, diagnosis and treatment planning, and clinical impression techniques and fabrication technology are discussed.

  18. Machine Learning Techniques for the Detection of Shockable Rhythms in Automated External Defibrillators

    PubMed Central

    Irusta, Unai; Morgado, Eduardo; Aramendi, Elisabete; Ayala, Unai; Wik, Lars; Kramer-Johansen, Jo; Eftestøl, Trygve; Alonso-Atienza, Felipe

    2016-01-01

    Early recognition of ventricular fibrillation (VF) and electrical therapy are key for the survival of out-of-hospital cardiac arrest (OHCA) patients treated with automated external defibrillators (AED). AED algorithms for VF-detection are customarily assessed using Holter recordings from public electrocardiogram (ECG) databases, which may be different from the ECG seen during OHCA events. This study evaluates VF-detection using data from both OHCA patients and public Holter recordings. ECG-segments of 4-s and 8-s duration were analyzed. For each segment 30 features were computed and fed to state of the art machine learning (ML) algorithms. ML-algorithms with built-in feature selection capabilities were used to determine the optimal feature subsets for both databases. Patient-wise bootstrap techniques were used to evaluate algorithm performance in terms of sensitivity (Se), specificity (Sp) and balanced error rate (BER). Performance was significantly better for public data with a mean Se of 96.6%, Sp of 98.8% and BER 2.2% compared to a mean Se of 94.7%, Sp of 96.5% and BER 4.4% for OHCA data. OHCA data required two times more features than the data from public databases for an accurate detection (6 vs 3). No significant differences in performance were found for different segment lengths, the BER differences were below 0.5-points in all cases. Our results show that VF-detection is more challenging for OHCA data than for data from public databases, and that accurate VF-detection is possible with segments as short as 4-s. PMID:27441719

  19. Circulation detection using the electrocardiogram and the thoracic impedance acquired by defibrillation pads

    PubMed Central

    Alonso, Erik; Aramendi, Elisabete; Daya, Mohamud; Irusta, Unai; Chicote, Beatriz; Russell, James K.; Tereshchenko, Larisa G.

    2016-01-01

    Aim To develop and evaluate a method to detect circulation in the presence of organized rhythms (ORs) during resuscitation using signals acquired by defibrillation pads. Methods Segments containing electrocardiogram (ECG) and thoracic impedance (TI) signals free of artifacts were used. The ECG corresponded to ORs classified as pulseless electrical acitivity (PEA) or pulse-generating rhythm (PR). A first dataset containing 1091 segments was split into training and test sets to develop and validate the circulation detector. The method processed ECG and TI to obtain the impedance circulation component (ICC). Morphological features were extracted from ECG and ICC, and combined into a classifier to discriminate between PEA and PR. The performance of the method was evaluated in terms of sensitivity (PR) and specificity (PEA). A second dataset (86 segments from different patients) was used to assess two application of the method: confirmation of arrest by recognizing absence of circulation during ORs and detection of return of spontaneous circulation (ROSC) during resuscitation. In both cases, time to confirmation of arrest/ROSC was determined. Results The method showed a sensitivity/specificity of 92.1%/90.3% and 92.2%/91.9% for training and test sets respectively. The method confirmed cardiac arrest with a specificity of 93.3% with a median delay of 0 s after the first OR annotation. ROSC was detected with a sensitivity of 94.4% with a median delay of 57 s from ROSC onset. Conclusion The method showed good performance, and can be reliably used to distinguish perfusing from non-perfusing ORs. PMID:26705970

  20. Teeth and implants.

    PubMed

    Palmer, R

    1999-08-28

    An osseointegrated implant restoration may closely resemble a natural tooth. However, the absence of a periodontal ligament and connective tissue attachment via cementum, results in fundamental differences in the adaptation of the implant to occlusal forces, and the structure of the gingival cuff.

  1. A no bleed implant.

    PubMed

    Ersek, R A; Navarro, J A; Nemeth, D Z; Sas, G

    1993-01-01

    Breast implants have evolved from the original saline-filled, smooth-surfaced silicone rubber bag to silicone gel-filled smooth-walled sacs to a combination of a silicone gel-filled bag within a saline-filled sac, and, most recently, a reversed, double-lumen implant with a saline bag inside of a gel-filled bag. Texture-surfaced implants were first used in 1970 when the standard silicone gel-filled implant was covered with a polyurethane foam. Because of concerns about the degradation products of this foam, they were removed from the market in 1991. In 1975 double-lumen silicone textured implants were developed, followed by silicone gel-filled textured implants. In 1990 a new radiolucent, biocompatible gel was produced that reduced the problem of radioopacity of silicone implants. Because of the gel's sufficiently low coefficient of friction, leakage caused by fold flaw fracture may also be decreased. We present a case where this new biocompatible gel implant was repositioned after four months. The resulting scar capsule in this soft breast was thin [< 0.002 cm (0.008 in.)] and evenly textured as a mirror image of the textured silicone surface. Scanning electron microscopy and x-ray defraction spectrophotometry revealed no silicone bleed.

  2. Smoking and dental implants

    PubMed Central

    Kasat, V.; Ladda, R.

    2012-01-01

    Smoking is a prevalent behaviour in the population. The aim of this review is to bring to light the effects of smoking on dental implants. These facts will assist dental professionals when implants are planned in tobacco users. A search of “PubMed” was made with the key words “dental implant,” “nicotine,” “smoking,” “tobacco,” and “osseointegration.” Also, publications on tobacco control by the Government of India were considered. For review, only those articles published from 1988 onward in English language were selected. Smoking has its influence on general as well as oral health of an individual. Tobacco negatively affects the outcome of almost all therapeutic procedures performed in the oral cavity. The failure rate of implant osseointegration is considerably higher among smokers, and maintenance of oral hygiene around the implants and the risk of peri-implantitis are adversely affected by smoking. To increase implant survival in smokers, various protocols have been recommended. Although osseointegrated dental implants have become the state of the art for tooth replacement, they are not without limitations or complications. In this litigious era, it is extremely important that the practitioner clearly understands and is able and willing to convey the spectrum of possible complications and their frequency to the patients. PMID:24478965

  3. Batteryless implanted echosonometer

    NASA Technical Reports Server (NTRS)

    Kojima, G. K.

    1977-01-01

    Miniature ultrasonic echosonometer implanted within laboratory animals obtains energy from RF power oscillator that is electronically transduced via induction loop to power receiving loop located just under animal's skin. Method of powering device offers significant advantages over those in which battery is part of implanted package.

  4. Implantable CMOS Biomedical Devices

    PubMed Central

    Ohta, Jun; Tokuda, Takashi; Sasagawa, Kiyotaka; Noda, Toshihiko

    2009-01-01

    The results of recent research on our implantable CMOS biomedical devices are reviewed. Topics include retinal prosthesis devices and deep-brain implantation devices for small animals. Fundamental device structures and characteristics as well as in vivo experiments are presented. PMID:22291554

  5. Implantable, Ingestible Electronic Thermometer

    NASA Technical Reports Server (NTRS)

    Kleinberg, Leonard

    1987-01-01

    Small quartz-crystal-controlled oscillator swallowed or surgically implanted provides continuous monitoring of patient's internal temperature. Receiver placed near patient measures oscillator frequency, and temperature inferred from previously determined variation of frequency with temperature. Frequency of crystal-controlled oscillator varies with temperature. Circuit made very small and implanted or ingested to measure internal body temperature.

  6. Automatic transmission control method

    SciTech Connect

    Hasegawa, H.; Ishiguro, T.

    1989-07-04

    This patent describes a method of controlling an automatic transmission of an automotive vehicle. The transmission has a gear train which includes a brake for establishing a first lowest speed of the transmission, the brake acting directly on a ring gear which meshes with a pinion, the pinion meshing with a sun gear in a planetary gear train, the ring gear connected with an output member, the sun gear being engageable and disengageable with an input member of the transmission by means of a clutch. The method comprises the steps of: detecting that a shift position of the automatic transmission has been shifted to a neutral range; thereafter introducing hydraulic pressure to the brake if present vehicle velocity is below a predetermined value, whereby the brake is engaged to establish the first lowest speed; and exhausting hydraulic pressure from the brake if present vehicle velocity is higher than a predetermined value, whereby the brake is disengaged.

  7. Automatic Abstraction in Planning

    NASA Technical Reports Server (NTRS)

    Christensen, J.

    1991-01-01

    Traditionally, abstraction in planning has been accomplished by either state abstraction or operator abstraction, neither of which has been fully automatic. We present a new method, predicate relaxation, for automatically performing state abstraction. PABLO, a nonlinear hierarchical planner, implements predicate relaxation. Theoretical, as well as empirical results are presented which demonstrate the potential advantages of using predicate relaxation in planning. We also present a new definition of hierarchical operators that allows us to guarantee a limited form of completeness. This new definition is shown to be, in some ways, more flexible than previous definitions of hierarchical operators. Finally, a Classical Truth Criterion is presented that is proven to be sound and complete for a planning formalism that is general enough to include most classical planning formalisms that are based on the STRIPS assumption.

  8. Automatic speech recognition

    NASA Astrophysics Data System (ADS)

    Espy-Wilson, Carol

    2005-04-01

    Great strides have been made in the development of automatic speech recognition (ASR) technology over the past thirty years. Most of this effort has been centered around the extension and improvement of Hidden Markov Model (HMM) approaches to ASR. Current commercially-available and industry systems based on HMMs can perform well for certain situational tasks that restrict variability such as phone dialing or limited voice commands. However, the holy grail of ASR systems is performance comparable to humans-in other words, the ability to automatically transcribe unrestricted conversational speech spoken by an infinite number of speakers under varying acoustic environments. This goal is far from being reached. Key to the success of ASR is effective modeling of variability in the speech signal. This tutorial will review the basics of ASR and the various ways in which our current knowledge of speech production, speech perception and prosody can be exploited to improve robustness at every level of the system.

  9. Automatic carrier acquisition system

    NASA Technical Reports Server (NTRS)

    Bunce, R. C. (Inventor)

    1973-01-01

    An automatic carrier acquisition system for a phase locked loop (PLL) receiver is disclosed. It includes a local oscillator, which sweeps the receiver to tune across the carrier frequency uncertainty range until the carrier crosses the receiver IF reference. Such crossing is detected by an automatic acquisition detector. It receives the IF signal from the receiver as well as the IF reference. It includes a pair of multipliers which multiply the IF signal with the IF reference in phase and in quadrature. The outputs of the multipliers are filtered through bandpass filters and power detected. The output of the power detector has a signal dc component which is optimized with respect to the noise dc level by the selection of the time constants of the filters as a function of the sweep rate of the local oscillator.

  10. Automatic vehicle monitoring

    NASA Technical Reports Server (NTRS)

    Bravman, J. S.; Durrani, S. H.

    1976-01-01

    Automatic vehicle monitoring systems are discussed. In a baseline system for highway applications, each vehicle obtains position information through a Loran-C receiver in rural areas and through a 'signpost' or 'proximity' type sensor in urban areas; the vehicle transmits this information to a central station via a communication link. In an advance system, the vehicle carries a receiver for signals emitted by satellites in the Global Positioning System and uses a satellite-aided communication link to the central station. An advanced railroad car monitoring system uses car-mounted labels and sensors for car identification and cargo status; the information is collected by electronic interrogators mounted along the track and transmitted to a central station. It is concluded that automatic vehicle monitoring systems are technically feasible but not economically feasible unless a large market develops.

  11. Automatic Retinal Oximetry

    NASA Astrophysics Data System (ADS)

    Halldorsson, G. H.; Karlsson, R. A.; Hardarson, S. H.; Mura, M. Dalla; Eysteinsson, T.; Beach, J. M.; Stefansson, E.; Benediktsson, J. A.

    2007-10-01

    This paper presents a method for automating the evaluation of hemoglobin oxygen saturation in the retina. This method should prove useful for monitoring ischemic retinal diseases and the effect of treatment. In order to obtain saturation values automatically, spectral images must be registered in pairs, the vessels of the retina located and measurement points must be selected. The registration algorithm is based on a data driven approach that circumvents many of the problems that have plagued previous methods. The vessels are extracted using an algorithm based on morphological profiles and supervised classifiers. Measurement points on retinal arterioles and venules as well as reference points on the adjacent fundus are automatically selected. Oxygen saturation values along vessels are averaged to arrive at a more accurate estimate of the retinal vessel oxygen saturation. The system yields reproducible results as well as being sensitive to changes in oxygen saturation.

  12. Percutaneous and skeletal biocarbon implants

    NASA Technical Reports Server (NTRS)

    Mooney, V.

    1977-01-01

    Review of carbon implants developed by NASA discussed four different types of implants and subsequent improvements. Improvements could be of specific interest to rehabilitation centers and similar organizations.

  13. Automatic Word Alignment

    DTIC Science & Technology

    2014-02-18

    strategy was evalu­ ated in the context of English -to-Pashto (E2P) and Pashto-to- English (P2E), a low-resource language pair. For E2P, the training and...improves the quality of automatic word alignment, for example for resource poor language pairs, thus improving Statistical Machine Translation (SMT...example for resource poor language pairs, thus improving Statistical Machine Translation (SMT) performance. 15. SUBJECT TERMS 16. SECURITY

  14. Automatic Test Equipment

    DTIC Science & Technology

    1980-02-28

    Search Terms Automatic Test Equipment Frequency Analyzers Oscilloscopes Pulse Analyzers Signal Generators "Etc." Third Level Search Guided...VAST Building Block Equipment RF Test Point Control Switch Digital Multimeter Frequency and Time Interval Meter Digital Word Generator Delay...Generator RF Amplifier, 95 Hz-2 GHz RF Amplifier, 2-4 GHz RF Amplifier, 4-8 GHz RF Amplifier, 8-12.2 GHz Signal Generator, 0.1 Hz-50 kHz

  15. Automatic Microwave Network Analysis.

    DTIC Science & Technology

    A program and procedure are developed for the automatic measurement of microwave networks using a Hewlett-Packard network analyzer and programmable calculator . The program and procedure are used in the measurement of a simple microwave two port network. These measurements are evaluated by comparing with measurements on the same network using other techniques. The programs...in the programmable calculator are listed in Appendix 1. The step by step procedure used is listed in Appendix 2. (Author)

  16. Graphene for Biomedical Implants

    NASA Astrophysics Data System (ADS)

    Moore, Thomas; Podila, Ramakrishna; Alexis, Frank; Rao, Apparao; Clemson Bioengineering Team; Clemson Physics Team

    2013-03-01

    In this study, we used graphene, a one-atom thick sheet of carbon atoms, to modify the surfaces of existing implant materials to enhance both bio- and hemo-compatibility. This novel effort meets all functional criteria for a biomedical implant coating as it is chemically inert, atomically smooth and highly durable, with the potential for greatly enhancing the effectiveness of such implants. Specifically, graphene coatings on nitinol, a widely used implant and stent material, showed that graphene coated nitinol (Gr-NiTi) supports excellent smooth muscle and endothelial cell growth leading to better cell proliferation. We further determined that the serum albumin adsorption on Gr-NiTi is greater than that of fibrinogen, an important and well understood criterion for promoting a lower thrombosis rate. These hemo-and biocompatible properties and associated charge transfer mechanisms, along with high strength, chemical inertness and durability give graphene an edge over most antithrombogenic coatings for biomedical implants and devices.

  17. Experimental and theoretical investigation of implantable cardiac pacemaker exposed to low frequency magnetic field.

    PubMed

    Babouri, A; Hedjeidj, A; Guendouz, L

    2009-04-01

    This paper presents in vitro investigation of an implantable cardiac pacemaker exposed to low frequency magnetic fields. The method used in this study is based on the interaction by inductive coupling through the loop formed by the pacemaker and its loads and the surrounding medium. This interaction results in an induced electromotive force between the terminals of the pacemaker, which can potentially disturb its operation. The studied frequencies are 50/60 Hz and 10/25 kHz. The experimental tests were carried out on several cardiac pacemakers, single chamber, and dual chamber. The results show a window effect of the detection circuits of cardiac pacemakers for the four studied frequencies. The modelling of the test bed requires studying the effects of the induced currents generated by the application of a magnetic field. Analytical calculations and Numerical simulations were carried out. We modelled the interactions of the magnetic field with a simplified representation of pacemaker embedded in the medium. The comparison of the results in the air and in vitro enabled us to make an equivalent electric model. The results obtained in experimental and theoretical studies allowed us to validate the test bed. The method applied is valid for other medical implants such as cardiac defibrillators, implant hearing aids system...etc.

  18. Technologies for Prolonging Cardiac Implantable Electronic Device Longevity.

    PubMed

    Lau, Ernest W

    2017-01-01

    Prolonged longevity of cardiac implantable electronic devices (CIEDs) is needed not only as a passive response to match the prolonging life expectancy of patient recipients, but will also actively prolong their life expectancy by avoiding/deferring the risks (and costs) associated with device replacement. CIEDs are still exclusively powered by nonrechargeable primary batteries, and energy exhaustion is the dominant and an inevitable cause of device replacement. The longevity of a CIED is thus determined by the attrition rate of its finite energy reserve. The energy available from a battery depends on its capacity (total amount of electric charge), chemistry (anode, cathode, and electrolyte), and internal architecture (stacked plate, folded plate, and spiral wound). The energy uses of a CIED vary and include a background current for running electronic circuitry, periodic radiofrequency telemetry, high-voltage capacitor reformation, constant ventricular pacing, and sporadic shocks for the cardiac resynchronization therapy defibrillators. The energy use by a CIED is primarily determined by the patient recipient's clinical needs, but the energy stored in the device battery is entirely under the manufacturer's control. A larger battery capacity generally results in a longer-lasting device, but improved battery chemistry and architecture may allow more space-efficient designs. Armed with the necessary technical knowledge, healthcare professionals and purchasers will be empowered to make judicious selection on device models and maximize the utilization of all their energy-saving features, to prolong device longevity for the benefits of their patients and healthcare systems.

  19. Delayed right ventricular defibrillation lead perforation presenting as cardiac tamponade and treated surgically.

    PubMed

    Noguchi, Masahiko; Nakai, Toshiko; Kawano, Yuji; Shibayama, Kentaro; Obunai, Kotaro; Tabata, Minoru; Watanabe, Hiroyuki

    2017-04-01

    Right ventricular perforation leading to cardiac tamponade can occur during the chronic phase after cardiac device implantation. Physicians who manage the pacemaker clinic must be alert to the wide range of symptoms and signs that can accompany delayed right ventricular perforation. Surgical rather than percutaneous lead extraction may be prudent.

  20. Automatic Training of Rat Cyborgs for Navigation.

    PubMed

    Yu, Yipeng; Wu, Zhaohui; Xu, Kedi; Gong, Yongyue; Zheng, Nenggan; Zheng, Xiaoxiang; Pan, Gang

    2016-01-01

    A rat cyborg system refers to a biological rat implanted with microelectrodes in its brain, via which the outer electrical stimuli can be delivered into the brain in vivo to control its behaviors. Rat cyborgs have various applications in emergency, such as search and rescue in disasters. Prior to a rat cyborg becoming controllable, a lot of effort is required to train it to adapt to the electrical stimuli. In this paper, we build a vision-based automatic training system for rat cyborgs to replace the time-consuming manual training procedure. A hierarchical framework is proposed to facilitate the colearning between rats and machines. In the framework, the behavioral states of a rat cyborg are visually sensed by a camera, a parameterized state machine is employed to model the training action transitions triggered by rat's behavioral states, and an adaptive adjustment policy is developed to adaptively adjust the stimulation intensity. The experimental results of three rat cyborgs prove the effectiveness of our system. To the best of our knowledge, this study is the first to tackle automatic training of animal cyborgs.

  1. Automatic Training of Rat Cyborgs for Navigation

    PubMed Central

    Yu, Yipeng; Wu, Zhaohui; Xu, Kedi; Gong, Yongyue; Zheng, Nenggan; Zheng, Xiaoxiang; Pan, Gang

    2016-01-01

    A rat cyborg system refers to a biological rat implanted with microelectrodes in its brain, via which the outer electrical stimuli can be delivered into the brain in vivo to control its behaviors. Rat cyborgs have various applications in emergency, such as search and rescue in disasters. Prior to a rat cyborg becoming controllable, a lot of effort is required to train it to adapt to the electrical stimuli. In this paper, we build a vision-based automatic training system for rat cyborgs to replace the time-consuming manual training procedure. A hierarchical framework is proposed to facilitate the colearning between rats and machines. In the framework, the behavioral states of a rat cyborg are visually sensed by a camera, a parameterized state machine is employed to model the training action transitions triggered by rat's behavioral states, and an adaptive adjustment policy is developed to adaptively adjust the stimulation intensity. The experimental results of three rat cyborgs prove the effectiveness of our system. To the best of our knowledge, this study is the first to tackle automatic training of animal cyborgs. PMID:27436999

  2. Automated External Defibrillators and Survival After In-Hospital Cardiac Arrest

    PubMed Central

    Chan, Paul S.; Krumholz, Harlan M.; Spertus, John A.; Jones, Philip G.; Cram, Peter; Berg, Robert A.; Peberdy, Mary Ann; Nadkarni, Vinay; Mancini, Mary E.; Nallamothu, Brahmajee K.

    2013-01-01

    Context Automated external defibrillators (AEDs) improve survival from out-of-hospital cardiac arrests, but data on their effectiveness in hospitalized patients are limited. Objective To evaluate the association of AED use and survival for in-hospital cardiac arrest. Design, Setting, Patients Cohort study of 11,695 hospitalized patients with cardiac arrests between January 1, 2000 and August 26, 2008 at 204 hospitals following the introduction of AEDs on general hospital wards. Main Outcome Measure Survival to hospital discharge by AED use, using multivariable hierarchical regression analyses to adjust for patient factors and hospital site. Results Of 11,695 patients, 9616 (82.2%) had non-shockable rhythms (asystole and pulseless electrical activity) and 2079 (17.8%) had shockable rhythms (ventricular fibrillation and pulseless ventricular tachycardia). AEDs were used in 4515 (38.6%) patients. Overall, 2117 (18.1%) patients survived to hospital discharge. Within the entire study population, AED use was associated with a lower rate of survival after in-hospital cardiac arrest compared with no AED use (16.3% vs. 19.3%; adjusted rate ratio (RR), 0.85; 95% confidence interval (CI), 0.78–0.92; P<0.001). Among cardiac arrests due to non-shockable rhythms, AED use was associated with lower survival (10.4% vs. 15.4%; adjusted RR, 0.74; 95% CI, 0.65–0.83; P<.001). In contrast, for cardiac arrests due to shockable rhythms, AED use was not associated with survival (38.4% vs. 39.8%; adjusted RR, 1.00; 95% CI, 0.88–1.13; P=0.99). These patterns were consistently observed in both monitored and non-monitored hospital units where AEDs were used, after matching patients to the individual units in each hospital where the cardiac arrest occurred, and with a propensity score analysis. Conclusion Use of AEDs in hospitalized patients with cardiac arrest is not associated with improved survival. PMID:21078809

  3. Single implant tooth replacement.

    PubMed

    Briley, T F

    1998-01-01

    It has been shown that direct bone anchorage of dental implants will provide long-term predictability for single tooth implants and multi-unit implants. The function of implant-supported restoration is now routinely achieved. The real challenge facing the restorative dentist and laboratory technician is to achieve optimal aesthetics. The learning objective of this article is to review the prosthodontic procedures essential to maximizing natural aesthetics in implant supported restorations. It will provide a review of master impression techniques, prepable titanium abutments and designing the cement on restoration. Particular emphasis is directed to the soft tissue model from which a series of sequenced techniques can be followed to achieve optimal aesthetics. Analysis of the implant alignment with regard to the neighboring teeth will result in having to make a choice of which prepable abutment will maximize the aesthetic result. The following case outlines how to replace a single missing tooth using an externally hexed implant system and a prefabricated titanium abutment on a 26-year-old male patient.

  4. Boron implanted strontium titanate

    NASA Astrophysics Data System (ADS)

    Cooper, C. J. M.

    Single crystals of strontium titanate implanted with boron were found to have highly conductive surface layers. The effects of varying dose from 10 to the 16th power to 10 to the 17th power ions/sq cm, implantation voltage from 50 to 175 keV and annealing conditions on the room temperature surface resistance and Hall mobility are presented. Variation of the implantation voltage did not have a major effect on the sheet resistances obtained by boron implantation of strontium titanate, while dose and annealing conditions have major effects. Doses of 5 x 10 to the 16th power ions/sq cm required annealing on the order of one hour at 500 K for maximum reduction of the room temperature resistance in the implanted layer. Samples implanted with a dose of 1 x 10 to the 17th power ions/sq cm required slightly higher temperatures (approximately 575 K) to obtain a minimum resistance at room temperature. Long term (several weeks) room temperature annealing was found to occur in high dose samples. After one to two months at room temperature followed by an anneal to 575 K, the surface resistances were found to be lower than those produced by the annealing of a freshly implanted sample to 575 K.

  5. Dental Implant Systems

    PubMed Central

    Oshida, Yoshiki; Tuna, Elif B.; Aktören, Oya; Gençay, Koray

    2010-01-01

    Among various dental materials and their successful applications, a dental implant is a good example of the integrated system of science and technology involved in multiple disciplines including surface chemistry and physics, biomechanics, from macro-scale to nano-scale manufacturing technologies and surface engineering. As many other dental materials and devices, there are crucial requirements taken upon on dental implants systems, since surface of dental implants is directly in contact with vital hard/soft tissue and is subjected to chemical as well as mechanical bio-environments. Such requirements should, at least, include biological compatibility, mechanical compatibility, and morphological compatibility to surrounding vital tissues. In this review, based on carefully selected about 500 published articles, these requirements plus MRI compatibility are firstly reviewed, followed by surface texturing methods in details. Normally dental implants are placed to lost tooth/teeth location(s) in adult patients whose skeleton and bony growth have already completed. However, there are some controversial issues for placing dental implants in growing patients. This point has been, in most of dental articles, overlooked. This review, therefore, throws a deliberate sight on this point. Concluding this review, we are proposing a novel implant system that integrates materials science and up-dated surface technology to improve dental implant systems exhibiting bio- and mechano-functionalities. PMID:20480036

  6. Nanotechnology for dental implants.

    PubMed

    Tomsia, Antoni P; Lee, Janice S; Wegst, Ulrike G K; Saiz, Eduardo

    2013-01-01

    With the advent of nanotechnology, an opportunity exists for the engineering of new dental implant materials. Metallic dental implants have been successfully used for decades, but they have shortcomings related to osseointegration and mechanical properties that do not match those of bone. Absent the development of an entirely new class of materials, faster osseointegration of currently available dental implants can be accomplished by various surface modifications. To date, there is no consensus regarding the preferred method(s) of implant surface modification, and further development will be required before the ideal implant surface can be created, let alone become available for clinical use. Current approaches can generally be categorized into three areas: ceramic coatings, surface functionalization, and patterning on the micro- to nanoscale. The distinctions among these are imprecise, as some or all of these approaches can be combined to improve in vivo implant performance. These surface improvements have resulted in durable implants with a high percentage of success and long-term function. Nanotechnology has provided another set of opportunities for the manipulation of implant surfaces in its capacity to mimic the surface topography formed by extracellular matrix components of natural tissue. The possibilities introduced by nanotechnology now permit the tailoring of implant chemistry and structure with an unprecedented degree of control. For the first time, tools are available that can be used to manipulate the physicochemical environment and monitor key cellular events at the molecular level. These new tools and capabilities will result in faster bone formation, reduced healing time, and rapid recovery to function.

  7. Biomedical implantable microelectronics.

    PubMed

    Meindl, J D

    1980-10-17

    Innovative applications of microelectronics in new biomedical implantable instruments offer a singular opportunity for advances in medical research and practice because of two salient factors: (i) beyond all other types of biomedical instruments, implants exploit fully the inherent technical advantages--complex functional capability, high reliability, lower power drain, small size and weight-of microelectronics, and (ii) implants bring microelectronics into intimate association with biological systems. The combination of these two factors enables otherwise impossible new experiments to be conducted and new paostheses developed that will improve the quality of human life.

  8. Automatic tuning of flexible interventional RF receiver coils.

    PubMed

    Venook, Ross D; Hargreaves, Brian A; Gold, Garry E; Conolly, Steven M; Scott, Greig C

    2005-10-01

    Microcontroller-based circuitry was built and tested for automatically tuning flexible RF receiver coils at the touch of a button. This circuitry is robust to 10% changes in probe center frequency, is in line with the scanner, and requires less than 1 s to tune a simple probe. Images were acquired using this circuitry with a varactor-tunable 1-inch flexible probe in a phantom and in an in vitro porcine knee model. The phantom experiments support the use of automatic tuning by demonstrating 30% signal-to-noise ratio (SNR) losses for 5% changes in coil center frequency, in agreement with theoretical calculations. Comparisons between patellofemoral cartilage images obtained using a 3-inch surface coil and the surgically-implanted 1-inch flexible coil reveal a worst-case local SNR advantage of a factor of 4 for the smaller coil. This work confirms that surgically implanted coils can greatly improve resolution in small-field-of-view (FOV) applications, and demonstrates the importance and feasibility of automatically tuning such probes.

  9. Automatic range selector

    DOEpatents

    McNeilly, Clyde E.

    1977-01-04

    A device is provided for automatically selecting from a plurality of ranges of a scale of values to which a meter may be made responsive, that range which encompasses the value of an unknown parameter. A meter relay indicates whether the unknown is of greater or lesser value than the range to which the meter is then responsive. The rotatable part of a stepping relay is rotated in one direction or the other in response to the indication from the meter relay. Various positions of the rotatable part are associated with particular scales. Switching means are sensitive to the position of the rotatable part to couple the associated range to the meter.

  10. AUTOMATIC FREQUENCY CONTROL SYSTEM

    DOEpatents

    Hansen, C.F.; Salisbury, J.D.

    1961-01-10

    A control is described for automatically matching the frequency of a resonant cavity to that of a driving oscillator. The driving oscillator is disconnected from the cavity and a secondary oscillator is actuated in which the cavity is the frequency determining element. A low frequency is mixed with the output of the driving oscillator and the resultant lower and upper sidebands are separately derived. The frequencies of the sidebands are compared with the secondary oscillator frequency. deriving a servo control signal to adjust a tuning element in the cavity and matching the cavity frequency to that of the driving oscillator. The driving oscillator may then be connected to the cavity.

  11. Automatic Speech Recognition

    NASA Astrophysics Data System (ADS)

    Potamianos, Gerasimos; Lamel, Lori; Wölfel, Matthias; Huang, Jing; Marcheret, Etienne; Barras, Claude; Zhu, Xuan; McDonough, John; Hernando, Javier; Macho, Dusan; Nadeu, Climent

    Automatic speech recognition (ASR) is a critical component for CHIL services. For example, it provides the input to higher-level technologies, such as summarization and question answering, as discussed in Chapter 8. In the spirit of ubiquitous computing, the goal of ASR in CHIL is to achieve a high performance using far-field sensors (networks of microphone arrays and distributed far-field microphones). However, close-talking microphones are also of interest, as they are used to benchmark ASR system development by providing a best-case acoustic channel scenario to compare against.

  12. Computer automation of high current ion implanters

    NASA Astrophysics Data System (ADS)

    Woodard, Ollie; Lindsey, Paul; Cecil, Joseph; Pipe, Robert

    1985-01-01

    Complete computer automation of a high current ion implanter has been achieved. Special design considerations were necessary for automation including the development of a simplified ion source, a simplified beam transport control function, and a computer aided real-time feedback dosimetry control system. A special, versatile software architecture was also necessary to allow protected operation by unskilled operators, as well as diagnostic and maintenance modes accessible only to qualified personnel. Integral mounting of the DEC LSI-11 computer in the implanter frame provided additional challenges regarding EMI control and the electrical isolation required. The end result is a system in which all pertinent functions of the implanter are computer monitored and controlled continuously, allowing for automatic set-up, operation, on-line fault detection and diagnostics, with recovery software to correct many transient problems as they occur. This paper will discuss both general and specific solutions to the design problems encountered, and will review the system performance from a user point of view.

  13. Biocompatibility of surgical implants

    NASA Technical Reports Server (NTRS)

    Kaelble, D. H.

    1979-01-01

    Method of selecting biocompatible materials for surgical implants uses fracture mechanic relationships and surface energies of candidate materials in presence of blood plasma. Technique has been used to characterize 190 materials by parameters that reflect their biocompatibility.

  14. Risks of Breast Implants

    MedlinePlus

    ... has traveled to other parts of the body. Connective Tissue Disease The FDA has not detected any association between silicone gel-filled breast implants and connective tissue disease, breast cancer, or reproductive problems. In order ...

  15. Breast Reconstruction with Implants

    MedlinePlus

    ... removes your breast to treat or prevent breast cancer. One type of breast reconstruction uses breast implants — silicone devices filled with silicone gel or salt water (saline) — to reshape your breasts. Breast reconstruction ...

  16. Urinary incontinence - injectable implant

    MedlinePlus

    Intrinsic sphincter deficiency repair; ISD repair; Injectable bulking agents for stress urinary incontinence ... Urine leakage that gets worse Pain where the injection was done Allergic reaction to the material Implant ...

  17. Breast reconstruction - implants

    MedlinePlus

    ... cosmetic surgery after breast cancer can improve your sense of well-being and your quality of life. Alternative Names Breast implants surgery References Roehl KR, Wilhelmi BJ, Phillips LG. Breast reconstruction. ...

  18. Superelastic Orthopedic Implant Coatings

    NASA Astrophysics Data System (ADS)

    Fournier, Eric; Devaney, Robert; Palmer, Matthew; Kramer, Joshua; El Khaja, Ragheb; Fonte, Matthew

    2014-07-01

    The demand for hip and knee replacement surgery is substantial and growing. Unfortunately, most joint replacement surgeries will fail within 10-25 years, thereby requiring an arduous, painful, and expensive revision surgery. To address this issue, a novel orthopedic implant coating material ("eXalt") has been developed. eXalt is comprised of super elastic nitinol wire that is knit into a three-dimensional spacer fabric structure. eXalt expands in vivo to conform to the implantation site and is porous to allow for bone ingrowth. The safety and efficacy of eXalt were evaluated through structural analysis, mechanical testing, and a rabbit implantation model. The results demonstrate that eXalt meets or exceeds the performance of current coating technologies with reduced micromotion, improved osseointegration, and stronger implant fixation in vivo.

  19. Automatic readout micrometer

    DOEpatents

    Lauritzen, T.

    A measuring system is described for surveying and very accurately positioning objects with respect to a reference line. A principle use of this surveying system is for accurately aligning the electromagnets which direct a particle beam emitted from a particle accelerator. Prior art surveying systems require highly skilled surveyors. Prior art systems include, for example, optical surveying systems which are susceptible to operator reading errors, and celestial navigation-type surveying systems, with their inherent complexities. The present invention provides an automatic readout micrometer which can very accurately measure distances. The invention has a simplicity of operation which practically eliminates the possibilities of operator optical reading error, owning to the elimination of traditional optical alignments for making measurements. The invention has an extendable arm which carries a laser surveying target. The extendable arm can be continuously positioned over its entire length of travel by either a coarse of fine adjustment without having the fine adjustment outrun the coarse adjustment until a reference laser beam is centered on the target as indicated by a digital readout. The length of the micrometer can then be accurately and automatically read by a computer and compared with a standardized set of alignment measurements. Due to its construction, the micrometer eliminates any errors due to temperature changes when the system is operated within a standard operating temperature range.

  20. Automatic readout micrometer

    DOEpatents

    Lauritzen, Ted

    1982-01-01

    A measuring system is disclosed for surveying and very accurately positioning objects with respect to a reference line. A principal use of this surveying system is for accurately aligning the electromagnets which direct a particle beam emitted from a particle accelerator. Prior art surveying systems require highly skilled surveyors. Prior art systems include, for example, optical surveying systems which are susceptible to operator reading errors, and celestial navigation-type surveying systems, with their inherent complexities. The present invention provides an automatic readout micrometer which can very accurately measure distances. The invention has a simplicity of operation which practically eliminates the possibilities of operator optical reading error, owning to the elimination of traditional optical alignments for making measurements. The invention has an extendable arm which carries a laser surveying target. The extendable arm can be continuously positioned over its entire length of travel by either a coarse or fine adjustment without having the fine adjustment outrun the coarse adjustment until a reference laser beam is centered on the target as indicated by a digital readout. The length of the micrometer can then be accurately and automatically read by a computer and compared with a standardized set of alignment measurements. Due to its construction, the micrometer eliminates any errors due to temperature changes when the system is operated within a standard operating temperature range.

  1. Simple Implant Augmentation Rhinoplasty

    PubMed Central

    Nguyen, Anh H.; Bartlett, Erica L.; Kania, Katarzyna; Bae, Sang Mo

    2015-01-01

    Augmentation rhinoplasty among Asian patients is often performed to improve the height of the nasal dorsum. As the use of autogenous tissues poses certain limitations, alloplastic materials are a viable alternative with a long history of use in Asia. The superiority of one implant prosthesis over another for augmentation rhinoplasty is a matter of debate, with each material representing varying strengths and weaknesses, indications for use, and precautions to consider in nasal implant placement. An implant prosthesis should be used on a case-by-case basis. Augmentation rhinoplasty requires the consideration of specific anatomical preoperative factors, including the external nose, nasal length, nasofrontal angle, humps, and facial proportions. It is equally important to consider several operative guidelines to appropriately shape implants to minimize the occurrence of adverse effects and postoperative complications. The most common postoperative complications include infection, nasal height change, movement of implant prosthesis, and silicone implant protrusion. In addition, the surgeon should consider the current standards of Asian beauty aesthetics to better understand the patient's desired outcome. PMID:26648804

  2. Biomaterials in cochlear implants

    PubMed Central

    Stöver, Timo; Lenarz, Thomas

    2011-01-01

    The cochlear implant (CI) represents, for almost 25 years now, the gold standard in the treatment of children born deaf and for postlingually deafened adults. These devices thus constitute the greatest success story in the field of ‘neurobionic’ prostheses. Their (now routine) fitting in adults, and especially in young children and even babies, places exacting demands on these implants, particularly with regard to the biocompatibility of a CI’s surface components. Furthermore, certain parts of the implant face considerable mechanical challenges, such as the need for the electrode array to be flexible and resistant to breakage, and for the implant casing to be able to withstand external forces. As these implants are in the immediate vicinity of the middle-ear mucosa and of the junction to the perilymph of the cochlea, the risk exists – at least in principle – that bacteria may spread along the electrode array into the cochlea. The wide-ranging requirements made of the CI in terms of biocompatibility and the electrode mechanism mean that there is still further scope – despite the fact that CIs are already technically highly sophisticated – for ongoing improvements to the properties of these implants and their constituent materials, thus enhancing the effectiveness of these devices. This paper will therefore discuss fundamental material aspects of CIs as well as the potential for their future development. PMID:22073103

  3. Contraceptive implants and lactation.

    PubMed

    Díaz, Soledad

    2002-01-01

    The safety and efficacy of four contraceptive implants, plant, Implanon, Nestorone and Elcometrine, have been evaluated during use in the postpartum period by lactating women. These implants provide highly effective contraceptive protection with no negative effect on breastfeeding or infant growth and development. Breastfeeding women initiating Norplant use in the second postpartum month experience significantly longer periods of amenorrhea than do untreated women or intrauterine device users. After weaning, the bleeding pattern is similar to that observed in non-nursing women. Norplant use does not affect bone turnover and density during lactation. Norplant and Implanon release orally active progestins while Nestorone and Elcometrine implants release an orally inactive progestin, which represents an advantage since the infant should be free of steroidal effects. The infant's daily intake of steroids (estimated from concentrations in maternal milk during the first month of use) range from 90 to 100 ng of levonorgestrel (Norplant), 75-120 ng of etonogestrel (Implanon), and 50 ng and 110 ng of Nestorone (Nestorone and Elcometrine implants, respectively). Nursing women needing contraception may use progestin-only implants when nonhormonal methods are not available or acceptable. Implants that deliver orally active steroids should only be used after 6 weeks postpartum to avoid transferring of steroids to the newborn.

  4. Biocompatible implant surface treatments.

    PubMed

    Pattanaik, Bikash; Pawar, Sudhir; Pattanaik, Seema

    2012-01-01

    Surface plays a crucial role in biological interactions. Surface treatments have been applied to metallic biomaterials in order to improve their wear properties, corrosion resistance, and biocompatibility. A systematic review was performed on studies investigating the effects of implant surface treatments on biocompatibility. We searched the literature using PubMed, electronic databases from 1990 to 2009. Key words such as implant surface topography, surface roughness, surface treatment, surface characteristics, and surface coatings were used. The search was restricted to English language articles published from 1990 to December 2009. Additionally, a manual search in the major dental implant journals was performed. When considering studies, clinical studies were preferred followed by histological human studies, animal studies, and in vitro studies. A total of 115 articles were selected after elimination: clinical studies, 24; human histomorphometric studies, 11; animal histomorphometric studies, 46; in vitro studies, 34. The following observations were made in this review: · The focus has shifted from surface roughness to surface chemistry and a combination of chemical manipulations on the porous structure. More investigations are done regarding surface coatings. · Bone response to almost all the surface treatments was favorable. · Future trend is focused on the development of osteogenic implant surfaces. Limitation of this study is that we tried to give a broader overview related to implant surface treatments. It does not give any conclusion regarding the best biocompatible implant surface treatment investigated till date. Unfortunately, the eventually selected studies were too heterogeneous for inference of data.

  5. [Larynx: implants and stents].

    PubMed

    Sittel, C

    2009-05-01

    There is a wide variety of devices and materials to be implanted into the human larynx. Some are intended to remain only for a period of time, like laryngeal stents. If removal is not intended the device meets the definition for a medical implant. The majority of implants is used for the treatment of unilateral vocal fold immobility. There a 2 types of implants serving this purpose: Implants in a stricter sense are devices of solid material, which are brought into the paraglottic space through a window in the laryngeal framework (medialization thyroplasty). Several different products are presented in this review. In contrast, there are different substances available for endoscopic injection into the paralyzed vocal fold (injection laryngoplasty). Since some of these substances show a corpuscular consistency and a high viscosity they need to be deposited into the lateral paraglottic space. Therefore, the term "injectable implants" has been coined for these materials. The different substances available are discussed in detail in this review. Laryngeal stents are primarily used in the early postoperative phase after open reconstruction of the larynx. The different devices available on the market are described with their specific characteristics and intended use.

  6. Automatic sets and Delone sets

    NASA Astrophysics Data System (ADS)

    Barbé, A.; von Haeseler, F.

    2004-04-01

    Automatic sets D\\subset{\\bb Z}^m are characterized by having a finite number of decimations. They are equivalently generated by fixed points of certain substitution systems, or by certain finite automata. As examples, two-dimensional versions of the Thue-Morse, Baum-Sweet, Rudin-Shapiro and paperfolding sequences are presented. We give a necessary and sufficient condition for an automatic set D\\subset{\\bb Z}^m to be a Delone set in {\\bb R}^m . The result is then extended to automatic sets that are defined as fixed points of certain substitutions. The morphology of automatic sets is discussed by means of examples.

  7. Automatic vehicle location system

    NASA Technical Reports Server (NTRS)

    Hansen, G. R., Jr. (Inventor)

    1973-01-01

    An automatic vehicle detection system is disclosed, in which each vehicle whose location is to be detected carries active means which interact with passive elements at each location to be identified. The passive elements comprise a plurality of passive loops arranged in a sequence along the travel direction. Each of the loops is tuned to a chosen frequency so that the sequence of the frequencies defines the location code. As the vehicle traverses the sequence of the loops as it passes over each loop, signals only at the frequency of the loop being passed over are coupled from a vehicle transmitter to a vehicle receiver. The frequencies of the received signals in the receiver produce outputs which together represent a code of the traversed location. The code location is defined by a painted pattern which reflects light to a vehicle carried detector whose output is used to derive the code defined by the pattern.

  8. Automatic routing module

    NASA Technical Reports Server (NTRS)

    Malin, Janice A.

    1987-01-01

    Automatic Routing Module (ARM) is a tool to partially automate Air Launched Cruise Missile (ALCM) routing. For any accessible launch point or target pair, ARM creates flyable routes that, within the fidelity of the models, are optimal in terms of threat avoidance, clobber avoidance, and adherence to vehicle and planning constraints. Although highly algorithmic, ARM is an expert system. Because of the heuristics applied, ARM generated routes closely resemble manually generated routes in routine cases. In more complex cases, ARM's ability to accumulate and assess threat danger in three dimensions and trade that danger off with the probability of ground clobber results in the safest path around or through difficult areas. The tools available prior to ARM did not provide the planner with enough information or present it in such a way that ensured he would select the safest path.

  9. AUTOMATIC HAND COUNTER

    DOEpatents

    Mann J.R.; Wainwright, A.E.

    1963-06-11

    An automatic, personnel-operated, alpha-particle hand monitor is described which functions as a qualitative instrument to indicate to the person using it whether his hands are cold'' or hot.'' The monitor is activated by a push button and includes several capacitor-triggered thyratron tubes. Upon release of the push button, the monitor starts the counting of the radiation present on the hands of the person. If the count of the radiation exceeds a predetermined level within a predetermined time, then a capacitor will trigger a first thyratron tube to light a hot'' lamp. If, however, the count is below such level during this time period, another capacitor will fire a second thyratron to light a safe'' lamp. (AEC)

  10. Automatic Bayesian polarity determination

    NASA Astrophysics Data System (ADS)

    Pugh, D. J.; White, R. S.; Christie, P. A. F.

    2016-07-01

    The polarity of the first motion of a seismic signal from an earthquake is an important constraint in earthquake source inversion. Microseismic events often have low signal-to-noise ratios, which may lead to difficulties estimating the correct first-motion polarities of the arrivals. This paper describes a probabilistic approach to polarity picking that can be both automated and combined with manual picking. This approach includes a quantitative estimate of the uncertainty of the polarity, improving calculation of the polarity probability density function for source inversion. It is sufficiently fast to be incorporated into an automatic processing workflow. When used in source inversion, the results are consistent with those from manual observations. In some cases, they produce a clearer constraint on the range of high-probability source mechanisms, and are better constrained than source mechanisms determined using a uniform probability of an incorrect polarity pick.

  11. Networked Automatic Optical Telescopes

    NASA Astrophysics Data System (ADS)

    Mattox, J. R.

    2000-05-01

    Many groups around the world are developing automated or robotic optical observatories. The coordinated operation of automated optical telescopes at diverse sites could provide observing prospects which are not otherwise available, e.g., continuous optical photometry without diurnal interruption. Computer control and scheduling also offers the prospect of effective response to transient events such as γ -ray bursts. These telescopes could also serve science education by providing high-quality CCD data for educators and students. The Automatic Telescope Network (ATN) project has been undertaken to promote networking of automated telescopes. A web site is maintained at http://gamma.bu.edu/atn/. The development of such networks will be facilitated by the existence of standards. A set of standard commands for instrument and telescope control systems will allow for the creation of software for an ``observatory control system'' which can be used at any facility which complies with the TCS and ICS standards. Also, there is a strong need for standards for the specification of observations to be done, and reports on the results and status of observations. A proposed standard for this is the Remote Telescope Markup Language (RTML), which is expected to be described in another poster in this session. It may thus be feasible for amateur-astronomers to soon buy all necessary equipment and software to field an automatic telescope. The owner/operator could make otherwise unused telescope time available to the network in exchange for the utilization of other telescopes in the network --- including occasional utilization of meter-class telescopes with research-grade CCD detectors at good sites.

  12. Automatic Coal-Mining System

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr.

    1985-01-01

    Coal cutting and removal done with minimal hazard to people. Automatic coal mine cutting, transport and roof-support movement all done by automatic machinery. Exposure of people to hazardous conditions reduced to inspection tours, maintenance, repair, and possibly entry mining.

  13. Minimally Invasive Catheter Procedures to Assist Complicated Pacemaker Lead Extraction and Implantation in the Operating Room

    SciTech Connect

    Kroepil, Patric; Lanzman, Rotem S. Miese, Falk R.; Blondin, Dirk; Winter, Joachim; Scherer, Axel; Fuerst, Guenter

    2011-04-15

    We report on percutaneous catheter procedures in the operating room (OR) to assist complicated manual extraction or insertion of pacemaker (PM) and implantable cardioverter defibrillator leads. We retrospectively reviewed complicated PM revisions and implantations performed between 2004 and 2009 that required percutaneous catheter procedures performed in the OR. The type of interventional procedure, catheter and retrieval system used, venous access, success rates, and procedural complications were analyzed. In 41 (12 female and 29 male [mean age 62 {+-} 17 years]) of 3021 (1.4%) patients, standard manual retrieval of old leads or insertion of new leads was not achievable and thus required percutaneous catheter intervention for retrieval of misplaced leads and/or recanalisation of occluded central veins. Thirteen of 18 (72.2%) catheter-guided retrieval procedures for misplaced (right atrium [RA] or ventricle [RV; n = 3], superior vena cava [n = 2], brachiocephalic vein [n = 5], and subclavian vein [n = 3]) lead fragments in 16 patients were successful. Percutaneous catheter retrieval failed in five patients because there were extremely fixed or adhered lead fragments. Percutaneous transluminal angiography (PTA) of central veins for occlusion or high-grade stenosis was performed in 25 patients. In 22 of 25 patients (88%), recanalization of central veins was successful, thus enabling subsequent lead replacement. Major periprocedural complications were not observed. In the case of complicated manual PM lead implantation or revision, percutaneous catheter-guided extraction of misplaced lead fragments or recanalisation of central veins can be performed safely in the OR, thus enabling subsequent implantation or revision of PM systems in the majority of patients.

  14. Minimally invasive catheter procedures to assist complicated pacemaker lead extraction and implantation in the operating room.

    PubMed

    Kröpil, Patric; Lanzman, Rotem S; Miese, Falk R; Blondin, Dirk; Winter, Joachim; Scherer, Axel; Fürst, Günter

    2011-04-01

    We report on percutaneous catheter procedures in the operating room (OR) to assist complicated manual extraction or insertion of pacemaker (PM) and implantable cardioverter defibrillator leads. We retrospectively reviewed complicated PM revisions and implantations performed between 2004 and 2009 that required percutaneous catheter procedures performed in the OR. The type of interventional procedure, catheter and retrieval system used, venous access, success rates, and procedural complications were analyzed. In 41 (12 female and 29 male [mean age 62 ± 17 years]) of 3021 (1.4%) patients, standard manual retrieval of old leads or insertion of new leads was not achievable and thus required percutaneous catheter intervention for retrieval of misplaced leads and/or recanalisation of occluded central veins. Thirteen of 18 (72.2%) catheter-guided retrieval procedures for misplaced (right atrium [RA] or ventricle [RV; n = 3], superior vena cava [n = 2], brachiocephalic vein [n = 5], and subclavian vein [n = 3]) lead fragments in 16 patients were successful. Percutaneous catheter retrieval failed in five patients because there were extremely fixed or adhered lead fragments. Percutaneous transluminal angiography (PTA) of central veins for occlusion or high-grade stenosis was performed in 25 patients. In 22 of 25 patients (88%), recanalization of central veins was successful, thus enabling subsequent lead replacement. Major periprocedural complications were not observed. In the case of complicated manual PM lead implantation or revision, percutaneous catheter-guided extraction of misplaced lead fragments or recanalisation of central veins can be performed safely in the OR, thus enabling subsequent implantation or revision of PM systems in the majority of patients.

  15. Extraoral prostheses using extraoral implants.

    PubMed

    Pekkan, G; Tuna, S H; Oghan, F

    2011-04-01

    The aim of this study was to evaluate extraoral prostheses and the use of extraoral implants in patients with facial defects. 10 cases were treated utilizing maxillofacial prostheses employing extraoral implants in five cases. 16 extraoral implants were installed. Seven implants were placed in irradiated sites in the orbital regions. Six implants were placed in mastoid regions and three in a zygoma region that was irradiated. Two implants failed before initial integration was achieved in irradiated areas. Using 14 extraoral implants as anchors, five extraoral prostheses were set. The other five cases were treated with extraoral prostheses without using extraoral implants due to cost and patient-related factors. The data included age, sex, primary disease, implant length, implant failure, prosthetic attachment, radiation therapy, and peri-implant skin reactions. The use of extraoral implants for the retention of extraoral prostheses has simplified the placement, removal, and cleaning of the prosthesis by the patient. The stability of the prostheses was improved by anchors. Clinical and technical problems are presented with the techniques used for their resolution. Using extraoral implants resulted in a high rate of success in retaining facial prostheses and gave good stability and aesthetic satisfaction.

  16. Towards biodegradable wireless implants.

    PubMed

    Boutry, Clémentine M; Chandrahalim, Hengky; Streit, Patrick; Schinhammer, Michael; Hänzi, Anja C; Hierold, Christofer

    2012-05-28

    A new generation of partially or even fully biodegradable implants is emerging. The idea of using temporary devices is to avoid a second surgery to remove the implant after its period of use, thereby improving considerably the patient's comfort and safety. This paper provides a state-of-the-art overview and an experimental section that describes the key technological challenges for making biodegradable devices. The general considerations for the design and synthesis of biodegradable components are illustrated with radiofrequency-driven resistor-inductor-capacitor (RLC) resonators made of biodegradable metals (Mg, Mg alloy, Fe, Fe alloys) and biodegradable conductive polymer composites (polycaprolactone-polypyrrole, polylactide-polypyrrole). Two concepts for partially/fully biodegradable wireless implants are discussed, the ultimate goal being to obtain a fully biodegradable sensor for in vivo sensing.

  17. Development of a microcontroller-based automatic control system for the electrohydraulic total artificial heart.

    PubMed

    Kim, H C; Khanwilkar, P S; Bearnson, G B; Olsen, D B

    1997-01-01

    An automatic physiological control system for the actively filled, alternately pumped ventricles of the volumetrically coupled, electrohydraulic total artificial heart (EHTAH) was developed for long-term use. The automatic control system must ensure that the device: 1) maintains a physiological response of cardiac output, 2) compensates for an nonphysiological condition, and 3) is stable, reliable, and operates at a high power efficiency. The developed automatic control system met these requirements both in vitro, in week-long continuous mock circulation tests, and in vivo, in acute open-chested animals (calves). Satisfactory results were also obtained in a series of chronic animal experiments, including 21 days of continuous operation of the fully automatic control mode, and 138 days of operation in a manual mode, in a 159-day calf implant.

  18. Automatic Command Sequence Generation

    NASA Technical Reports Server (NTRS)

    Fisher, Forest; Gladded, Roy; Khanampompan, Teerapat

    2007-01-01

    Automatic Sequence Generator (Autogen) Version 3.0 software automatically generates command sequences for the Mars Reconnaissance Orbiter (MRO) and several other JPL spacecraft operated by the multi-mission support team. Autogen uses standard JPL sequencing tools like APGEN, ASP, SEQGEN, and the DOM database to automate the generation of uplink command products, Spacecraft Command Message Format (SCMF) files, and the corresponding ground command products, DSN Keywords Files (DKF). Autogen supports all the major multi-mission mission phases including the cruise, aerobraking, mapping/science, and relay mission phases. Autogen is a Perl script, which functions within the mission operations UNIX environment. It consists of two parts: a set of model files and the autogen Perl script. Autogen encodes the behaviors of the system into a model and encodes algorithms for context sensitive customizations of the modeled behaviors. The model includes knowledge of different mission phases and how the resultant command products must differ for these phases. The executable software portion of Autogen, automates the setup and use of APGEN for constructing a spacecraft activity sequence file (SASF). The setup includes file retrieval through the DOM (Distributed Object Manager), an object database used to store project files. This step retrieves all the needed input files for generating the command products. Depending on the mission phase, Autogen also uses the ASP (Automated Sequence Processor) and SEQGEN to generate the command product sent to the spacecraft. Autogen also provides the means for customizing sequences through the use of configuration files. By automating the majority of the sequencing generation process, Autogen eliminates many sequence generation errors commonly introduced by manually constructing spacecraft command sequences. Through the layering of commands into the sequence by a series of scheduling algorithms, users are able to rapidly and reliably construct the

  19. [The establishment of three methods to improve the management of implantable medical device].

    PubMed

    Zhong, Jianping; Ge, Yi

    2011-01-01

    Based on the managerial deficiencies of Implantable medical device, using the RFID technology, the automatically comparison of data, Intelligent logistics, this article has established three conceptional methods of the original system of increment and iterative development. And details are included in aspect of principle, framework and etc. Meanwhile, advices have been given in the scientific and effective management of the medical instrument.

  20. Hydroxylapatite Otologic Implants

    SciTech Connect

    McMillan, A.D.; Lauf, R.J.; Beale, B.; Johnson, R.

    2000-01-01

    A Cooperative Research and Development Agreement (CRADA) between Lockheed Martin Energy Research Corporation (LMER) and Smith and Nephew Richards Inc. of Bartlett, TN, was initiated in March 1997. The original completion date for the Agreement was March 25, 1998. The purpose of this work is to develop and commercialize net shape forming methods for directly creating dense hydroxylapatite (HA) ceramic otologic implants. The project includes three tasks: (1) modification of existing gelcasting formulations to accommodate HA slurries; (2) demonstration of gelcasting to fabricate green HA ceramic components of a size and shape appropriate to otologic implants: and (3) sintering and evaluation of the HA components.