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Sample records for automatic defibrillator implantation

  1. [Psychiatric complication of an implanted automatic defibrillator].

    PubMed

    Goëb, J L; Galloyer-Fortier, A; Dupuis, J M; Victor, J; Gohier, B; Garré, J B

    2003-12-01

    The implantable automatic defibrillator has completely changed the prognosis of potentially fatal ventricular arrhythmias by the delivery of an electric shock in the event of ventricular tachycardia or fibrillation. This vital device is sometimes poorly accepted from the psychological point of view by patients having been traumatised by experiences of sudden death from which they have been rescuscitated. Anxiety and depression are common and they have an important effect on the quality of life. The unpredictable occurrence of painful, multiple and uncontrollable electrical shocks may induce a state of acute stress with stunning, the resemblance of which to the model of learned helplessness described experimentally in the animal by Seligman, is discussed. The authors report the case of a 20 year old man whose automatic defibrillator was activated twenty times in one night. His state of stress and impotence was such that he lay prostate in his bed. Suicide seemed to be the only possible way of escaping from the electrical shocks of the device which was perceived as being dangerous. The management of this condition is not standardised but it requires the collaboration of the cardiac rhythmological and psychiatric teams. Medication with antidepressant drugs alone is not sufficient. The regulation of the sensitivity of the defibrillator gives the patient a feeling of mastering the situation: submission is not total! Research along this line should improve the patients' acceptation of the device and their quality of life. PMID:15248453

  2. The automatic implantable cardioverter-defibrillator.

    PubMed

    Mirowski, M; Reid, P R; Mower, M M; Watkins, L; Platia, E V; Griffith, L S; Juanteguy, J M

    1984-05-01

    The automatic implantable cardioverter-defibrillator is an electronic device designed to monitor the heart continuously, to identify malignant ventricular tachyarrhythmias, and then to deliver effective countershock to restore normal rhythm. There are two defibrillating electrodes which are also used for waveform analysis; one is located in the superior vena cava, the other is placed over the cardiac apex. A third bipolar right ventricular electrode serves for rate counting and R-wave synchronization. When ventricular fibrillation occurs, a 25 joule pulse is delivered; when ventricular tachycardia faster than a preset rate is detected, the discharge is R-wave synchronized. The device can recycle three times if required. Special batteries can deliver over 100 shocks or provide a 3-year monitoring life. Implantation of the device is made either through a thoracotomy or by a subxiphoid approach. Thus far, the device has been implanted in 160 patients with a follow-up of 42 months. Acceleration of ventricular tachycardia to a faster rhythm or to ventricular fibrillation occurred only rarely and is dealt with most successfully through recycling. Actuarial analysis of the initial 52 patients has indicated 22.9% one-year total mortality, a 52% decrease from the 48% mortality that would be expected in the same group of patients without the device; the mortality attributed to arrhythmias was only 8.5%. In conclusion, the automatic cardioverter-defibrillator can reliably identify and correct potentially lethal ventricular tachyarrhythmias, leading to a substantial increase in survival in properly selected high-risk patients. PMID:6204311

  3. 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.

  4. Manual vs. automatic capture management in implantable cardioverter defibrillators and cardiac resynchronization therapy defibrillators

    PubMed Central

    Murgatroyd, Francis D.; Helmling, Erhard; Lemke, Bernd; Eber, Bernd; Mewis, Christian; van der Meer-Hensgens, Judith; Chang, Yanping; Khalameizer, Vladimir; Katz, Amos

    2010-01-01

    Aims The Secura™ ICD and Consulta™ CRT-D are the first defibrillators to have automatic right atrial (RA), right ventricular (RV), and left ventricular (LV) capture management (CM). Complete CM was evaluated in an implantable cardioverter defibrillator (ICD) population. Methods and results Two prospective clinical studies were conducted in 28 centres in Europe and Israel. Automatic CM data were compared with manual threshold measurements, the CM applicability was determined, and adjustments to pacing outputs were analysed. In total, 160 patients [age 64.6 ± 10.4 years, 77% male, 80 ICD and 80 cardiac resynchronization therapy defibrillator (CRT-D)] were included. The differences between automatic and manual measurements were ≤0.25 V in 97% (RA CM) and 96% (RV CM) and were all within the safety margin. Fully automatic CM measurements were available within 1 week prior to the 3-month visit in 90% (RA), 99% (RV), and 97% (LV) of the patients. Results indicated increased output (threshold >2.5 V) due to raised RA threshold in seven (4.4%), high RV threshold in nine (5.6%), and high LV threshold in three patients (3.8%). All high threshold detections and all automatic modulations of pacing output were adjudicated appropriate. Conclusion Complete CM adjusts pacing output appropriately, permitting a reduction in office visits while it may maximize device longevity. The study was registered at ClinicalTrials.gov identifiers: NCT00526227 and NCT00526162. PMID:20231152

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

    PubMed

    Or, Friedman; Arik, Zaretski

    2016-08-01

    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

  6. 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

  7. 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

  8. [Wearable Automatic External Defibrillators].

    PubMed

    Luo, Huajie; Luo, Zhangyuan; Jin, Xun; Zhang, Leilei; Wang, Changjin; Zhang, Wenzan; Tu, Quan

    2015-11-01

    Defibrillation is the most effective method of treating ventricular fibrillation(VF), this paper introduces wearable automatic external defibrillators based on embedded system which includes EGG measurements, bioelectrical impedance measurement, discharge defibrillation module, which can automatic identify VF signal, biphasic exponential waveform defibrillation discharge. After verified by animal tests, the device can realize EGG acquisition and automatic identification. After identifying the ventricular fibrillation signal, it can automatic defibrillate to abort ventricular fibrillation and to realize the cardiac electrical cardioversion.

  9. A Canadian hospital's experience with the automatic implantable cardioverter/defibrillator.

    PubMed Central

    Sharma, A D; Guiraudon, G; Klein, G J; Yee, R

    1987-01-01

    The automatic implantable cardioverter/defibrillator is a device that can be implanted in patients for treatment of recurrent ventricular tachycardia and ventricular fibrillation. It was recently approved for clinical use in Canada. The authors describe their experience with 12 patients (mean age 51.3 years) who underwent implantation of a defibrillator. All 12 patients had a history of documented ventricular fibrillation, which was idiopathic in 3 and due to ischemic heart disease in 9. Electrophysiologic testing revealed inducible ventricular tachycardia or ventricular fibrillation in 8 of the 10 patients tested. An important criterion for selection for implantation was failure of pharmacologic therapy to suppress ventricular arrhythmias induced during electrophysiologic testing. Of the 12 patients, 1 died within 24 hours after implantation. During a mean follow-up period of 15.5 months there were no further deaths. All the surviving patients expressed satisfaction with the device; five of the seven under the age of 60 years have returned to work, and one has returned to school. This initial favourable experience with the automatic implantable cardioverter/defibrillator suggests that future increases in the availability of the device and improvements in its function will lead to much more widespread use, as the population of patients at risk of sudden cardiac death is large. Images Fig. 1 Fig. 2 Fig. 4 PMID:3442769

  10. Updated care guidelines for patients with automatic implantable cardioverter defibrillators.

    PubMed

    Moser, S A; Crawford, D; Thomas, A

    1993-04-01

    Since its clinical introduction, AICD therapy has gained significant acceptance. Some physicians consider it the "gold standard" in treating malignant tachyarrhythmias associated with sudden cardiac death. As the technology and therapy application have grown, nursing responsibilities have evolved as well. And, with the forthcoming combinations of technology such as AICDs with antitachycardia pacing and bradycardia pacing, the sophistication of the therapy is expected to increase. However, the most critical role for nurses in AICD patient care remains education. Increased utilization has made AICD implants more common, but many patients still lack the initial information and acceptance needed for therapeutic success. Health-care professionals who continue to update and share their understanding of this life-saving technology make invaluable contributions to the care of these patients who have received a second chance at life.

  11. [Postmarketing surveillance in patients with cardiac pace-makers or automatic implantable defibrillators].

    PubMed

    Fauchier, L; de Bouët du Portal, H; Giraudeau, C; Froger, S; Cosnay, P; Babuty, D

    2005-01-01

    This article includes an overview of the actual French control and regulation system of the safety alerts involving pacemakers and implantable cardioverter-defibrillator and an evaluation of the general information and trends about the characteristics of the reported incidents obtained in the last years in that field. The national security agencies have the mission to collect the data on safety and efficacy of medical devices but manufacturers, physicians and patients also have a role to play. The technical appreciation of the necessity of a notification is not easy in some cases but the lack of notification of a severe incident may lead to heavy penal consequences. If doubtful cases, one should keep in mind the spirit of these safety systems: a collective insurance against the risks related to the use of medical devices. In the 10 last years, the annual advisory rate was increased. The pacemakers were recalled more frequently than implantable cardioverter-defibrillators in absolute value but less frequently in relative value (advisories per 100 person-years). This increase may be related to the growing number of device implants and expanding indications for device therapy, to the increasing sophistication of the devices and to the modifications in the regulation aspects of these problems with a closer attention of users and physicians to the several types of malfunctions.

  12. Electromagnetic interference of automatic implantable cardioverter defibrillator and HeartWare left ventricular assist device.

    PubMed

    Labedi, Mohamed R; Alharethi, Rami; Kfoury, A G; Budge, Deborah; Bruce, Reid; Rasmusson, Brad; Bunch, T Jared

    2013-01-01

    The use of continuous-flow left ventricular assist devices (LVAD) have markedly improved outcomes in patients with advanced heart failure (HF). The HeartWare LVAD is a miniaturized centrifugal pump implanted within the pericardial space. Implantable cardioverter-defibrillators (ICDs) are susceptible to oversensing of extracardiac signals (electromagnetic interference [EMI]). We report two cases of EMI in patients that received a HeartWare LVAD as destination therapy for advanced HF. The patients were 75 and 78 years old, both with severe ischemic dilated cardiomyopathy (ejection fraction < 0.20) and New York Heart Association class 4 heart failure. Both patients had a St. Jude Medical Unify ICD with a 7 Fr dual coil St. Jude Medical Durata ICD lead. In both patients, the lead location was in the right ventricular apex with an inferior orientation. Both patients experienced immediate ICD therapies after LVAD placement, requiring the tachytherapies to be disabled. ICD programming changes to increase sensitivity and the detection windows were ineffective. Both patients underwent ICD system revision. In one patient, the existing lead was moved to an anteroseptal location that stopped the EMI. In the other patient, the ICD system was changed to allow a separate right ventricular sensing lead in an anteroseptal location and a dual coil ICD lead placed in an apical location, a strategy used to obtain an acceptable defibrillation threshold. The patients have had no subsequent EMI detected on clinical and remote monitoring. Patients with a right ventricular apical ICD lead placement that undergo placement of a HeartWare LVAD are susceptible to EMI and inappropriate ICD therapies. These cases suggest the primary mechanism is proximity of the ICD lead to the device and as such relocation to an anteroseptal location can overcome the problem. These data suggest that all patients that receive a HeartWare LVAD with an ICD should have the device carefully checked at maximum LVAD

  13. Elderly Benefit from Using Implantable Defibrillators

    MedlinePlus

    ... org Learn More Elderly benefit from using implantable defibrillators June 17, 2013 Categories: Heart News Study Highlights: Older people may benefit from implantable cardioverter defibrillators (ICDs) as much as younger people. Overall health, ...

  14. How Does an Implantable Cardioverter Defibrillator Work?

    MedlinePlus

    ... on Twitter. How Does an Implantable Cardioverter Defibrillator Work? An implantable cardioverter defibrillator (ICD) has wires with ... tune the programming of your ICD so it works better to correct irregular heartbeats. The type of ...

  15. [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.

  16. [Implantable cardioverter defibrillator: an update].

    PubMed

    le Heuzey, Jean-Yves; Aliot, Etienne

    2007-01-01

    Automatic implantable cardioverter defibrillator is now a well established therapy to prevent sudden cardiac death. In secondary prevention (patients with a previous cardiac arrest) defibrillator can be considered as a class I indication, if there is no transient or reversible cause. The level of proof is A. in primary prevention the defibrillator is indicated in coronary artery disease patients with or without symptoms of mild to moderate heart failure (NYHA II or III), an ejection fraction lower than 30 %, measured at least one month after a myocardial infarction and 3 months after a revascularisation, surgery or angioplasty (level of proof B). It is also indicated in symptomatic spontaneous sustained ventricular tachycardias with underlying heart disease (level of proof B), in patients with spontaneous sustained ventricular tachycardia, poorly tolerated, without underlying heart disease for which pharmacological treatment or ablation can not be performed or failed (level of proof B). Finally it is also indicated in patients with syncope of unknown cause with sustained ventricular tachycardia or inducible ventricular fibrillation, with an underlying heart disease (level of proof B). The guidelines proposed by the different societies have also proposed class IIa recommendations which are the following: coronary artery disease patients with left ventricular dysfunction (ejection fraction between 31 or 35 %) measured at least one month after a myocardial infarction and 3 months after a revascularisation with an inducible ventricular arrhythmia. It can be also indicated in idiopathic dilated cardiomyopathies with an ejection fraction lower than 30% and NYHA class II or III. It can be also indicated in familial or inherited conditions with a high risk of sudden cardiac death by ventricular fibrillation without any other efficient known treatment and finally in heart failure patients remaining symptomatic, in class III or IV NYHA, with an optimal medical therapy, an

  17. 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.

  18. Implantable cardioverter defibrillator - discharge

    MedlinePlus

    Baddour LM, Epstein AE, Erickson CC, et al. Update on cardiovascular implantable electronic device infections and their management: a scientific statement from the American Heart Association. Circulation . ...

  19. Implantable Cardioverter Defibrillators. Prophylactic Use

    PubMed Central

    2005-01-01

    of evidence for each outcome. The balance between benefits and harms, quality of evidence, applicability, and the certainty of the baseline risks are considered in judgments about the strength of recommendations. Summary of Findings Overall, ICDs are effective for the primary prevention of SCD. Three studies – the Multicentre Automatic Defibrillator Implantation Trial I (MADIT I), the Multicentre Automatic Defibrillator Implantation Trial II (MADIT II), and SCD-HeFT – showed there was a statistically significant decrease in total mortality for patients who prophylactically received an ICD compared with those who received conventional therapy (Table 1). Table 1: Results of Key Studies on the Use of Implantable Cardioverter Defibrillators for the Primary Prevention of Sudden Cardiac Death – All-Cause Mortality Study, * Year Population N Follow-up, Months Mortality, ICD† Group, % Mortality, Control Group, % Hazard Ratio (95% CI) P NNT† MADIT, 1996 (2) Ischemic 196 27 15.8 38.6 0.46 (0.26–0.82) .009 4 Priormyocardialinfarction Conventional therapy 54% relative reduction Ejection fraction ≤ 0.35NSVT†EP† + MADIT II, 2002 (3) Ischemic 1232 20 14.2 19.8 0.69(0.51–0.93) .016 18 Priormyocardialinfarction Conventional therapy 31% relative reduction Ejection fraction ≤ 0.30 SCD-HeFT, 2005 (4) Ischemic & Nonischemic 2521 60 22 29 0.77 (0.62–0.96) .007 13 Optimal therapy Ejection fraction < 0.35 23% relative reduction * MADIT I: Multicentre Automatic Defibrillator Implantation Trial I; MADIT II: Multicentre Automatic Defibrillator Implantation Trial II; SCD-HeFT: Sudden Cardiac Death in Heart Failure Trial. † EP indicates electrophysiology; ICD, implantable cardioverter defibrillator; NNT, number needed to treat; NSVT, nonsustained ventricular tachycardia. The NNT will appear higher if follow-up is short. For ICDs, the absolute benefit increases over time for at least a 5-year period; the NNT declines, often substantially, in studies with a longer follow

  20. Acute perforation in spite of implantation with an "antiperforation" defibrillator lead.

    PubMed

    Chien, Walter W; Chin, John

    2009-12-01

    A 74-year-old male underwent implantation of implantable cardioverter defibrillator per multicenter automatic defibrillator trial two criteria. The new St. Jude Medical Riata STS Durata defibrillator lead (St. Jude Medical, Sylmar, CA, USA) was used. This lead has a slight curve at the right ventricle shock coil and a silicone tip designed to decrease tip pressure at the endocardium interface. We presented a case of acute perforation during implantation of this lead. The patient was treated with pericardiocentesis and recovered.

  1. 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

  2. Indications for an implantable cardioverter defibrillator (ICD).

    PubMed

    Aizawa, Yoshifusa; Chinushi, Masaomi; Washizuka, Takashi

    2004-05-01

    Since the first clinical use of implantable defibrillator in human, the technology and the function of implantable cardioverter-defibrillator (ICD) have been much improved and now, ICD can be implanted within the chest wall. ICD is the most reliable therapy to prevent sudden cardiac death (SCD) in patients with documented VT/VF and the efficacy is most clear in patients with depressed heart function. It is now extended as a tool of the primary prevention of SCD in high risk patients after myocardial infarction. However, such beneficial effect is not applicable to DCM though patients might have depressed heart function. ICD is not free from procedure- or device-related problems which need to be resolved. From unknown causes, VT/VF might recur in an incessant form and an emergency admission is needed. Therefore, even during ICD therapy, patients often require antiarrhythmic drugs or catheter ablation. PMID:15206546

  3. Reliability systems for implantable cardiac defibrillator batteries

    NASA Astrophysics Data System (ADS)

    Takeuchi, Esther S.

    The reliability of the power sources used in implantable cardiac defibrillators is critical due to the life-saving nature of the device. Achieving a high reliability power source depends on several systems functioning together. Appropriate cell design is the first step in assuring a reliable product. Qualification of critical components and of the cells using those components is done prior to their designation as implantable grade. Product consistency is assured by control of manufacturing practices and verified by sampling plans using both accelerated and real-time testing. Results to date show that lithium/silver vanadium oxide cells used for implantable cardiac defibrillators have a calculated maximum random failure rate of 0.005% per test month.

  4. Legal aspects in implantable defibrillator extraction.

    PubMed

    D'Ovidio, C; Costantini, S; Vellante, P; Carnevale, A

    2013-10-01

    At the Institute of Legal Medicine in Chieti, a case of iatrogenic superior vena cava perforation was observed during laser extraction of an infected biventricular implantable cardiac defibrillator. The presentation of this particular case represented a starting point for studying the occurrence of similar complications in literature, since their knowledge and understanding should induce resolution of any organisation problems, aid in increasing physicians' training and impose the availability of cardiac surgeons during such operations.

  5. A second defibrillator chest patch electrode will increase implantation rates for nonthoracotomy defibrillators.

    PubMed

    Solomon, A J; Swartz, J F; Rodak, D J; Moore, H J; Hannan, R L; Tracy, C M; Fletcher, R D

    1996-09-01

    Nonthoracotomy defibrillator systems can be implanted with a lower morbidity and mortality, compared to epicardial systems. However, implantation may be unsuccessful in up to 15% of patients, using a monophasic waveform. It was the purpose of this study to prospectively examine the efficacy of a second chest patch electrode in a nonthoracotomy defibrillator system. Fourteen patients (mean age 62 +/- 11 years, ejection fraction = 0.29 +/- 0.12) with elevated defibrillation thresholds, defined as > or = 24 J, were studied. The initial lead system consisted of a right ventricular electrode (cathode), a left innominate vein, and subscapular chest patch electrode (anodes). If the initial defibrillation threshold was > or = 24 J, a second chest patch electrode was added. This was placed subcutaneously in the anterior chest (8 cases), or submuscularly in the subscapular space (6 cases). This resulted in a decrease in the system impedance at the defibrillation threshold, from 72.3 +/- 13.3 omega to 52.2 +/- 8.6 omega. Additionally, the defibrillation threshold decreased from > or = 24 J, with a single patch, to 16.6 +/- 2.8 J with two patches. These changes were associated with successful implantation of a nonthoracotomy defibrillator system in all cases. In conclusion, the addition of a second chest patch electrode (using a subscapular approach) will result in lower defibrillation thresholds in patients with high defibrillation thresholds, and will subsequently increase implantation rates for nonthoracotomy defibrillators.

  6. Cardiomyopathy and the use of implanted cardio-defibrillators in children.

    PubMed

    Kaminer, S J; Pickoff, A S; Dunnigan, A; Sterba, R; Wolff, G S

    1990-05-01

    Children and adults with cardiomyopathy and ventricular dysrhythmias have a uniformly poor prognosis, despite medical therapy. The use of automatic implantable cardio-defibrillators in adult patients with medically resistant ventricular dysrhythmias has resulted in a positive impact on survival. Because of its size and former lack of programmability, the device has been used rarely in children. Four patients with cardiomyopathy, in whom refractory ventricular dysrhythmias were managed with automatic implantable cardio-defibrillators, are presented. Two of these children are the youngest and smallest known in whom the device has been used; one of them received the first programmable model. The use of the automatic implantable cardio-defibrillator may enhance survival in selected young patients. PMID:1693196

  7. Biventricular implantable cardioverter defibrillator and inappropriate shocks.

    PubMed

    Srivathsan, Komandoor; Bazzell, Jane L; Lee, Richard W

    2003-01-01

    A 53-year-old man with nonischemic cardiomyopathy underwent implantation of a biventricular implantable cardioverter defibrillator (ICD) for symptomatic ventricular tachycardia. He received five shocks while attempting to exercise, 48 hours after implantation. Interrogation of the device revealed double counting of ventricular sensed events by the left and right ventricular leads. Shortening the AV delay and AV nodal blockade (beta-blocker) to promote ventricular pacing failed to prevent additional inappropriate ICD discharges. After detailed consideration of all options including AV nodal ablation, we chose to disconnect the left ventricular lead pending availability of newer devices with sensing functions limited to the right ventricular lead. Since then, the patient has not experienced any additional inappropriate discharges. PMID:12625617

  8. Subcutaneous chronic implantable defibrillation systems in humans.

    PubMed

    Cappato, Riccardo; Smith, Warren M; Hood, Margaret A; Crozier, Ian G; Jordaens, Luc; Spitzer, Stefan G; Ardashev, Andrey V; Boersma, Lucas; Lupo, Pierpaolo; Grace, Andrew A; Bardy, Gust H

    2012-09-01

    The recent introduction of subcutaneous implantable cardioverter defibrillator (S-ICD) has raised attention about the potential of this technology for clinical use in daily clinical practice. We review the methods and results of the four studies conducted in humans for approval of this innovative technology for daily practice. Two studies using a temporary S-ICD system (acute human studies) were conducted to search for an appropriate lead configuration and energy requirements. For this purpose, 4 S-ICD configurations were tested in 78 patients at the time of transvenous (TV)-ICD implantation. The optimal configuration was tested in 49 more patients to comparatively assess the subcutaneous defibrillation threshold (S-DFT) versus the standard TV-ICD. Long-term implants were evaluated in 55 patients using an implanted system (chronic human study). The acute humans studies led to an optimal S-ICD configuration comprising a parasternal electrode and left anterolateral thoracic pulse generator. Both configurations successfully terminated 98% of induced ventricular fibrillation (VF), but significantly higher energy levels were required with S-ICD than with TV-ICD systems (36.6 ± 19.8 J vs. 11.1 ± 8.5 J). In the chronic study, all 137 VF episodes induced at time of implant were detected with a 98% conversion rate. Two pocket infections and four lead revisions were required during 10 ± 1 months of follow-up. During this period, survival was 98%, and 12 spontaneous ventricular tachyarrhythmias were detected and treated by the device. These data show that the S-ICD systems here consistently detected and converted VF induced at time of implant as well as sustained ventricular tachyarrhythmias occurring during follow-up (248). PMID:22426601

  9. Implantable Cardiac Defibrillator Lead Failure and Management.

    PubMed

    Swerdlow, Charles D; Kalahasty, Gautham; Ellenbogen, Kenneth A

    2016-03-22

    The implantable-cardioverter defibrillator (ICD) lead is the most vulnerable component of the ICD system. Despite advanced engineering design, sophisticated manufacturing techniques, and extensive bench, pre-clinical, and clinical testing, lead failure (LF) remains the Achilles' heel of the ICD system. ICD LF has a broad range of adverse outcomes, ranging from intermittent inappropriate pacing to proarrhythmia leading to patient mortality. ICD LF is often considered in the context of design or construction defects, but is more appropriately considered in the context of the finite service life of a mechanical component placed in chemically stressful environment and subjected to continuous mechanical stresses. This clinical review summarizes LF mechanisms, assessment, and differential diagnosis of LF, including lead diagnostics, recent prominent lead recalls, and management of LF and functioning, but recalled leads. Despite recent advances in lead technology, physicians will likely continue to need to understand how to manage patients with transvenous ICD leads. PMID:26988958

  10. Implantable Cardiac Defibrillator Lead Failure and Management.

    PubMed

    Swerdlow, Charles D; Kalahasty, Gautham; Ellenbogen, Kenneth A

    2016-03-22

    The implantable-cardioverter defibrillator (ICD) lead is the most vulnerable component of the ICD system. Despite advanced engineering design, sophisticated manufacturing techniques, and extensive bench, pre-clinical, and clinical testing, lead failure (LF) remains the Achilles' heel of the ICD system. ICD LF has a broad range of adverse outcomes, ranging from intermittent inappropriate pacing to proarrhythmia leading to patient mortality. ICD LF is often considered in the context of design or construction defects, but is more appropriately considered in the context of the finite service life of a mechanical component placed in chemically stressful environment and subjected to continuous mechanical stresses. This clinical review summarizes LF mechanisms, assessment, and differential diagnosis of LF, including lead diagnostics, recent prominent lead recalls, and management of LF and functioning, but recalled leads. Despite recent advances in lead technology, physicians will likely continue to need to understand how to manage patients with transvenous ICD leads.

  11. When to consider an implantable cardioverter defibrillator following myocardial infarction?

    PubMed

    Szwejkowski, Benjamin R; Wright, Gary A; Connelly, Derek T; Gardner, Roy S

    2015-12-01

    After reading this article the reader should be familiar with: Current guidelines for implantable cardioverter defibrillator (ICD) use post myocardial infarction (MI) and ischaemic cardiomyopathy. Primary prevention ICD guidelines. Secondary prevention ICD guidelines. Non-sustained ventricular tachycardia in patients post MI and the use of ICDs. Programming ICDs. PMID:26526420

  12. 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.

  13. Runaway implantable defibrillator--a rare complication of radiation therapy.

    PubMed

    Nemec, Jan

    2007-05-01

    A case of a patient with runaway implantable cardioverter defibrillator (ICD) due to radiation therapy of a lung cancer is reported. This manifested as poorly tolerated wide complex tachycardia due to inappropriate rapid ventricular pacing, The event terminated with polymorphic VT, which inhibited pacing and ceased spontaneously before ICD discharge. The likely cause was corruption of device random access memory by ionizing radiation.

  14. [Comparative analyses of the reliability of automatic external defibrillators].

    PubMed

    Tchoudovski, I; Schlindwein, M; Jäger, M; Kikillus, N; Bolz, A

    2004-06-01

    Automatic external defibrillators are gaining increasing acceptance. Last year 6000 devices were installed in Germany. Since the average user has only limited medical knowledge, high demands have to be made on the automatic ECG diagnosis (fibrillation detection). Within the framework of this study a fully automatic test system that permits an objective comparison of the performance of the various devices available on the market was constructed. Older devices in particular do not always meet the requirements defined by international standards with regard to sensitivity and specificity. In addition, company philosophy appears to differ in terms of the preferential emphasis on sensitivity or specificity. Purchasers of such devices need take these findings into consideration.

  15. Double valve replacement in a patient with implantable cardioverter defibrillator with severe left ventricular dysfunction

    PubMed Central

    Manjunath, Girish; Rao, Prakash; Prakash, Nagendra; Shivaram, B. K.

    2016-01-01

    Recent data from landmark trials suggest that the indications for cardiac pacing and implantable cardioverter defibrillators (ICDs) are set to expand to include heart failure, sleep-disordered breathing, and possibly routine implantation in patients with myocardial infarction and poor ventricular function.[1] This will inevitably result in more patients with cardiac devices undergoing surgeries. Perioperative electromagnetic interference and their potential effects on ICDs pose considerable challenges to the anesthesiologists.[2] We present a case of a patient with automatic ICD with severe left ventricular dysfunction posted for double valve replacement. PMID:27716706

  16. Chagas' disease and the use of implantable cardioverter-defibrillators in Brazil.

    PubMed

    Rosa, Ronaldo F; Neto, Argemiro S; Franken, Roberto A

    2006-01-01

    The authors discuss the epidemiology and pathogenesis of Chagas' disease in Brazil, including the use of treatment with a cardioverter-defibrillator in patients with low ejection fraction. Select patients may benefit from resynchronization therapy associated with cardioverter-defibrillator treatment. Electrophysiologic study is indicated in the assessment of the potential utility of an implantable cardioverter-defibrillator. PMID:17086031

  17. Electroconvulsive therapy in the setting of implantable cardioverter-defibrillators.

    PubMed

    Davis, Asha; Zisselman, Marc; Simmons, Tony; McCall, W Vaughn; McCafferty, John; Rosenquist, Peter B

    2009-09-01

    Electroconvulsive therapy has potent cardiovascular effects, which may pose a challenge in treating patients with preexisting cardiac disease. Although it is well studied in the treatment of refractory depression, there are still pitfalls to overcome when treating those with comorbid cardiovascular disease. The synergistic effects of depression and cardiovascular disease in affecting the morbidity and mortality of patients make treatment a significant issue. The authors discuss 3 elderly patients treated for major depression, all of whom previously had implantable cardioverter-defibrillators placed. All 3 patients were effectively treated, with no major adverse effects. The cases illustrate how taking the appropriate preventative measures allow even the most medically challenging patient to undergo effective treatment and highlight the debate surrounding the intraoperative management of implantable cardioverter-defibrillator devices. PMID:19300291

  18. Implantable cardioverter defibrillator infection due to Mycobacterium mageritense.

    PubMed

    Fukunaga, Masato; Goya, Masahiko; Ogawa, Midori; Fukuda, Kazumasa; Taniguchi, Hatsumi; Ando, Kenji; Iwabuchi, Masashi; Miyazaki, Hiroaki

    2016-03-01

    Rapidly growing non-tuberculous mycobacteria (RGM) are usually detected in blood cultures after 4-5 days of incubation, so it is important to differentiate RGM from contamination of commensal organisms on human skin. We report an unusual case of Mycobacterium mageritense bacteremia and infection of an implantable cardioverter defibrillator originally misidentified as Corynebacterium spp. or Nocardia spp. in gram-stained smears. 16S rRNA gene sequencing had utility in the definitive identification of isolates. We should be aware that RGM infection may exist in repeated implantable device infections. PMID:26719132

  19. [Implantable cardioverter-defibrillator at the end of life].

    PubMed

    Pfeiffer, D; Hagendorff, A; Kühne, C; Reinhardt, S; Klein, N

    2015-06-01

    Brady- and tachyarrhythmias at the end of life are common observations. Implantable cardioverter-defibrillators answer with antibrady and antitachycardia pacing, which will not be associated with any complaints of the dying patient. In contrast, defibrillation and cardioversion shocks are extremely painful. Therefore shocks should be inactivated at the end of life. Family doctors, internists, emergency physicians and paramedics are unable to inactivate shocks. Deactivation of shocks at the end of life is not comparable to euthanasia or assisted suicide, but allow the patient to die at the end of an uncurable endstage disease. Deactivation of shocks should be discussed with the patient before initial implantation of the devices. The precise moment of the inactivation at the end of life should be discussed with patients and relatives. There is no common recommendation for the time schedule of this decision; therefore it should be based on the individual situation of the patient. Emergency health care physicians need magnets and sufficient information to inactivate defibrillators. The wishes of the patient have priority in the decision process and should be written in the patient's advance directive, which must be available in the final situation. However the physician must not necessarily follow every wish of the patient. As long as the laws in the European Union are not uniform, German recommendations are needed. PMID:26001358

  20. Antiarrhythmic Drug Therapy to Avoid Implantable Cardioverter Defibrillator Shocks

    PubMed Central

    Abboud, Jaber

    2016-01-01

    Implantable cardioverter defibrillators (ICDs) are effective in the prevention of arrhythmic sudden cardiac death. Many patients receiving an ICD are affected by heart failure and are at risk of ventricular arrhythmias, which may lead to appropriate shocks. On the other hand, in this population the incidence of atrial fibrillation, giving rise to inappropriate ICD shocks, is high. Accordingly, ICD discharges occur frequently and many patients with an ICD will need concomitant antiarrhythmic drug therapy to avoid or reduce the frequency of shocks. Therapeutic agents such as β-blockers, class I or class III antiarrhythmic drugs effectively suppress arrhythmias, but may have side-effects. Some drugs could eventually influence the function of ICDs by altering defibrillation or pacing threshold. Few prospective randomised trials are available, but current data suggest that amiodarone is most effective for prevention of appropriate or inappropriate ICD shocks. This review article summarises current knowledge regarding the antiarrhythmic management of patients with ICDs.

  1. Antiarrhythmic Drug Therapy to Avoid Implantable Cardioverter Defibrillator Shocks.

    PubMed

    Abboud, Jaber; R Ehrlich, Joachim

    2016-08-01

    Implantable cardioverter defibrillators (ICDs) are effective in the prevention of arrhythmic sudden cardiac death. Many patients receiving an ICD are affected by heart failure and are at risk of ventricular arrhythmias, which may lead to appropriate shocks. On the other hand, in this population the incidence of atrial fibrillation, giving rise to inappropriate ICD shocks, is high. Accordingly, ICD discharges occur frequently and many patients with an ICD will need concomitant antiarrhythmic drug therapy to avoid or reduce the frequency of shocks. Therapeutic agents such as β-blockers, class I or class III antiarrhythmic drugs effectively suppress arrhythmias, but may have side-effects. Some drugs could eventually influence the function of ICDs by altering defibrillation or pacing threshold. Few prospective randomised trials are available, but current data suggest that amiodarone is most effective for prevention of appropriate or inappropriate ICD shocks. This review article summarises current knowledge regarding the antiarrhythmic management of patients with ICDs. PMID:27617090

  2. Antiarrhythmic Drug Therapy to Avoid Implantable Cardioverter Defibrillator Shocks

    PubMed Central

    Abboud, Jaber

    2016-01-01

    Implantable cardioverter defibrillators (ICDs) are effective in the prevention of arrhythmic sudden cardiac death. Many patients receiving an ICD are affected by heart failure and are at risk of ventricular arrhythmias, which may lead to appropriate shocks. On the other hand, in this population the incidence of atrial fibrillation, giving rise to inappropriate ICD shocks, is high. Accordingly, ICD discharges occur frequently and many patients with an ICD will need concomitant antiarrhythmic drug therapy to avoid or reduce the frequency of shocks. Therapeutic agents such as β-blockers, class I or class III antiarrhythmic drugs effectively suppress arrhythmias, but may have side-effects. Some drugs could eventually influence the function of ICDs by altering defibrillation or pacing threshold. Few prospective randomised trials are available, but current data suggest that amiodarone is most effective for prevention of appropriate or inappropriate ICD shocks. This review article summarises current knowledge regarding the antiarrhythmic management of patients with ICDs. PMID:27617090

  3. Combined Subpectoral Implantation of Implantable Cardioverter-Defibrillator and Augmentation Mammoplasty in a Young Female Patient

    PubMed Central

    Kim, Dong-Jun; Park, Je Wook; Youn, Jong-Chan; Lee, Dong Won; Koo, Bon-Nyeo; Lee, Moon-Hyoung

    2016-01-01

    Subcutaneous implantation of a cardiac implantable electronic device is the standard method. Occasionally, subpectoral cardiac implantable electronic device (CIED) implantation via axillary incisions is performed in young female patients for cosmetic purposes. Because subpectoral CIED implantation and augmentation mammoplasty involve the same layer, it is feasible to perform both procedures simultaneously. We report a case of combined subpectoral implantation of an implantable cardioverter-defibrillator and augmentation mammoplasty via the axillary approach in a young female patient with dilated cardiomyopathy and small breasts. PMID:27721868

  4. 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

  5. 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.

  6. 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

  7. The Significance of Shocks in Implantable Cardioverter Defibrillator Recipients

    PubMed Central

    Li, Anthony; Kaura, Amit; Sunderland, Nicholas; Dhillon, Paramdeep S

    2016-01-01

    Large-scale implantable cardioverter defibrillator (ICD) trials have unequivocally shown a reduction in mortality in appropriately selected patients with heart failure and depressed left ventricular function. However, there is a strong association between shocks and increased mortality in ICD recipients. It is unclear if shocks are merely a marker of a more severe cardiovascular disease or directly contribute to the increase in mortality. The aim of this review is to examine the relationship between ICD shocks and mortality, and explore possible mechanisms. Data examining the effect of shocks in the absence of spontaneous arrhythmias as well as studies of non-shock therapy and strategies to reduce shocks are analysed to try and disentangle the shocks versus substrate debate.

  8. The Significance of Shocks in Implantable Cardioverter Defibrillator Recipients.

    PubMed

    Li, Anthony; Kaura, Amit; Sunderland, Nicholas; Dhillon, Paramdeep S; Scott, Paul A

    2016-08-01

    Large-scale implantable cardioverter defibrillator (ICD) trials have unequivocally shown a reduction in mortality in appropriately selected patients with heart failure and depressed left ventricular function. However, there is a strong association between shocks and increased mortality in ICD recipients. It is unclear if shocks are merely a marker of a more severe cardiovascular disease or directly contribute to the increase in mortality. The aim of this review is to examine the relationship between ICD shocks and mortality, and explore possible mechanisms. Data examining the effect of shocks in the absence of spontaneous arrhythmias as well as studies of non-shock therapy and strategies to reduce shocks are analysed to try and disentangle the shocks versus substrate debate. PMID:27617089

  9. The Significance of Shocks in Implantable Cardioverter Defibrillator Recipients

    PubMed Central

    Li, Anthony; Kaura, Amit; Sunderland, Nicholas; Dhillon, Paramdeep S

    2016-01-01

    Large-scale implantable cardioverter defibrillator (ICD) trials have unequivocally shown a reduction in mortality in appropriately selected patients with heart failure and depressed left ventricular function. However, there is a strong association between shocks and increased mortality in ICD recipients. It is unclear if shocks are merely a marker of a more severe cardiovascular disease or directly contribute to the increase in mortality. The aim of this review is to examine the relationship between ICD shocks and mortality, and explore possible mechanisms. Data examining the effect of shocks in the absence of spontaneous arrhythmias as well as studies of non-shock therapy and strategies to reduce shocks are analysed to try and disentangle the shocks versus substrate debate. PMID:27617089

  10. Generator and Lead-Related Complications of Implantable Cardioverter Defibrillators

    PubMed Central

    Yaminisharif, Ahmad; Soofizadeh, Nader; Shafiee, Akbar; Kazemisaeid, Ali; Jalali, Arash; Vasheghani-Farahani, Ali

    2014-01-01

    Background: Increase in the number of patients treated with Implantable Cardioverter Defibrillator (ICD) requests more attention regarding its complications. Objectives: This study aimed to assess the generator- and lead-related complications at implantation and during follow-up in the patients who were treated with ICD for primary and secondary prevention reasons. Methods: We retrospectively reviewed 255 consecutive patients who underwent transvenous ICD implantation for the first time in a 7-year period and were followed-up for 3 years at Tehran Heart Center. The personal and clinical data of the patients as well as specific data on the ICD implantation were retrieved. The frequency of each of the complications was reported and the study variables were compared between the patients with and without complications using Student’s t-test and chi-square test where appropriate. P values less than 0.05 were considered as statistically significant. Results: Out of a total of 525 implanted leads and 255 implanted devices in 255 patients (mean age = 62.57 ± 13.50 years; male = 196 [76.9%]), complications leading to generator or lead replacement occurred in 32 patients (12.5%). The results revealed no significant difference between the patients with and without complications regarding gender and age (P = 0.206 and P = 0.824, respectively). Also, no significant difference was found between the two groups concerning the ejection fraction (P = 0.271). Lead fracture was the most frequent lead-related complication and was observed in 17 patients (6.6%). Besides, it was mainly observed in the RV leads. Generator-related complications leading to generator replacement were observed in 2 patients (0.7%). Conclusions: Despite considerable improvements in the ICD technology, the rate of the ICD complications leading to device replacement and surgical revision, especially those related to the leads, is still clinically important. PMID:24936484

  11. 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.

  12. 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. PMID:25323413

  13. 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.

  14. [Fitness to drive in patients with implanted cardioverter-defibrillator].

    PubMed

    Klein, H H

    2012-09-01

    A physician who takes care for patients with implanted cardioverter-defibrillator (ICD) must inform them about their fitness to drive since these patients carry a higher risk for the occurrence of syncope or sudden cardiac death at the wheel. The driver's license law in Germany does not mention patients with ICD. The fitness to drive of patients with ICD is covered by the Advisory Board for Traffic Medicine in Germany (Bundesanstalt für Straßenwesen). These guidelines, however, are outdated and cannot be used to inform patients. Actually, these guidelines are under revision. Currently, the position paper of the German Society of Cardiology on "Fitness to drive and cardiovascular diseases" together with a recently published Dutch paper on this topic forms the basis of these recommendations. One week after ICD implantation for primary or one month after implantation for secondary prevention the patient may resume to drive. After adequate shocks the fitness to drive can be expected 2-4 months (3 months) later. The assessment of the fitness to drive has to be performed individually, taking into account also possible other influencing factors. In individual cases it appears to be justified that patients with ICD work as professional drivers.

  15. Anomalous ECG downloads from semi-automatic external defibrillators.

    PubMed

    Calle, P A; Vanhaute, O; Ranhoff, J F; Buylaert, W A

    1998-08-01

    The coincidental print-out by two different Laerdal systems (subsequently called 'system A' and 'system B') of the same medical control module (MCM) for a Laerdal Heartstart 2000 semi-automatic external defibrillator (SAED) led to the discovery of three deficiencies in the information storage and printing processes. First, we noted that the impedance reported via system A was consistently higher. Second, we found the attachment of 'mysterious' ECG samples in the reports from system B, but not from system A. A third problem was the unpredictable (in)ability of system B to print out the information from the MCMs. Further investigations with help from the company suggested that the above-mentioned problems were caused by incompatibilities between the software in the different parts of equipment used (i.e. SAED devices, MCMs, printing systems and a computer program to store the information in a database). These observations demonstrate the need for strict medical supervision on all aspects of a SAED project, and for feed-back from clinicians to manufacturers. PMID:9863574

  16. Remote monitoring and follow-up of pacemakers and implantable cardioverter defibrillators

    PubMed Central

    Burri, Haran; Senouf, David

    2009-01-01

    In the era of communication technology, new options are now available for following-up patients implanted with pacemakers (PMs) and defibrillators (ICDs). Most major companies offer devices with wireless capabilities that communicate automatically with home transmitters, which then relay data to the physician, thereby allowing remote patient follow-up and monitoring. These systems are being widely used in the USA for remote follow-up, and have been more recently introduced in Europe, where their adoption is increasing. In this article, we describe the currently existing systems, review the available evidence in the literature regarding remote follow-up and monitoring of PMs and ICDs, and finally discuss some unresolved issues. PMID:19470595

  17. Predictors of early mortality in implantable cardioverter-defibrillator recipients

    PubMed Central

    Stein, Kenneth M.; Mittal, Suneet; Gilliam, F. Roosevelt; Gilligan, David M.; Zhong, Qian; Kraus, Stacia Merkel; Meyer, Timothy E.

    2009-01-01

    Aims Multiple trials have shown that implantable cardioverter defibrillators (ICDs) prolong survival in secondary and primary prevention populations. However, in spite of the efficacy of these devices in terminating life-threatening arrhythmias, total mortality remains high. Methods and results We evaluated 1703 patients (mean age: 67 ± 12 years, 82% male) with conventional ICD indications, who were enrolled and followed between 2001 and 2004 at 128 US centres. Patients were followed for up to a year, and vital status was obtained for 1655 patients (97%, median follow-up: 377 days). There were 183 deaths within 1 year of ICD implantation (1-year mortality rate: 16%). Predictors of mortality included a history of atrial fibrillation (AF, P < 0.0001), diabetes (P = 0.0001), failure to use cholesterol-lowering medications (P < 0.001), use of digitalis and derivatives (P < 0.0001), use of diuretics (P < 0.0001), low body mass index (BMI, P < 0.0001), increasing age (P < 0.0001), low left ventricular ejection fraction (P < 0.0001), low activity hours (P < 0.0001), elevated resting heart rate (P = 0.014), low mean arterial pressure (MAP, P = 0.007), and poor functional status (New York Heart Association class, P < 0.0001). In multivariate modelling, AF (P ≤ 0.001), diabetes (P = 0.004), BMI (P = 0.001), MAP (P = 0.040), and functional class (P = 0.006) predicted mortality. Conclusion In this population undergoing ICD implantation, poor functional status, low MAP, diabetes, low BMI, and AF were strongly associated with death within a year. PMID:19279025

  18. Programming implantable cardioverter-defibrillators in primary prevention: higher or later.

    PubMed

    Clementy, Nicolas; Pierre, Bertrand; Simeon, Edouard; Lallemand, Bénédicte; Fauchier, Laurent; Babuty, Dominique

    2014-05-01

    Defibrillator shocks, appropriate or not, are associated with significant morbidity, as they decrease quality of life, can be involved in depression and anxiety, and are known to be proarrhythmic. Most recent data have even shown an association between shocks and overall mortality. As opposed to other defibrillator-related complications, the rate of inappropriate and unnecessary shocks can (and should) be decreased with adequate programming. This review focuses on the different programming strategies and tips available to reduce the rate of shocks in primary prevention patients with left ventricular dysfunction implanted with a defibrillator, as well as some of the manufacturers' device specificities.

  19. Y2K: effects on pacemaker and implantable defibrillator programmers.

    PubMed

    Flynn, D P; Daubert, J P; Huang, D T; Ocampo, C M; O'Gorman, E

    1999-01-01

    All permanent pacemakers and implantable defibrillators (PPM/ICDs) will continue to function as programmed without regard to the date in the year 2000 (Y2K). All manufacturers contacted reassured us that some of these devices incorporate a day/year clock in the circuitry; however, these are not involved in sensing or delivering programmed therapy. Some manufacturers' device programmers will roll over to the year 2000 without any problems at all, whereas others may have difficulty with date and time stamping on printed reports. We tested 14 different types of PPM/ICD programmers for Y2K compliance using 8 tests. Five of the 14 models passed each test and were labeled at our institution with a green "Y2K" sticker to identify them as Y2K compatible and needing no special attention after December 31, 1999. The most common test failed was the ability to roll the date forward from December 31, 1999, with the programmer power off. Organizations should consider testing and replacing noncompliant device programmers or placing a red sticker with "Y2K" crossed out on noncompliant pieces. The red sticker alerts the advanced practice nurse or physician to the need to confirm the appropriate date and time in the programmer after startup in the year 2000 and before interrogating or programming any PPM/ICD, to avoid inappropriate date and time stamping on printed reports from that programmer.

  20. 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.

  1. Sensing and detection in Medtronic implantable cardioverter defibrillators.

    PubMed

    Brown, Mark L; Swerdlow, Charles D

    2016-09-01

    Ensuring sensing and detection of ventricular tachycardia (VT) and ventricular fibrillation (VF) was a prerequisite for the clinical trials that established the survival benefit of implantable cardioverter defibrillators (ICDs). However, for decades, a high incidence of unnecessary shocks limited patients' and physicians' acceptance of ICD therapy. Oversensing, misclassification of supraventricular tachycardia (SVT) as VT, and self-terminating VT accounted for the vast majority of unnecessary shocks. Medtronic ICDs utilize sensitive baseline settings with minimal blanking periods to ensure accurate sensing of VF, VT, and SVT electrograms. Programmable algorithms reject oversensing caused by far-field R waves, T waves, and non-physiologic signals caused by lead failure. A robust hierarchy of SVT-VT discriminators minimize misclassification of SVT as VT. These features, combined with evidence-based programming, have reduced the 1‑year inappropriate shock rate to 1.5 % for dual-/triple-chamber ICDs and to 2.5 % for single-chamber ICDs. PMID:27624809

  2. Dual-chamber implantable cardioverter-defibrillator. Is it useful in patient with permanent atrial fibrillation?

    PubMed

    Porres-Aracama, José M; Cerezuela, José Luis; García-Urra, Francisco; Luque-Lezcano, Oscar; Herrero, Vicente

    2016-08-01

    In patients with permanent atrial fibrillation (AF) and implantable cardioverter-defibrillator (ICD) implant indication, a single-chamber device is the choice because AF does not provide interesting information for the treatment. It is very unusual to find patients with permanent AF that coexist with atrial tachycardia with various degree of Atrioventricular block. PMID:27525075

  3. Surgical techniques for implanting implantable cardioverter defibrillators in children and infants.

    PubMed

    Suzuki, Shoji; Motohashi, Shinya; Matsumoto, Masahiko

    2014-10-01

    Implantable cardioverter defibrillators (ICDs) are now being used in children. ICDs can be used to prevent sudden cardiac death caused by not only congenital heart defects, but also various non-structural diseases, such as long QT syndrome. However, a standard implantation technique for children, especially infants, has not yet been established. As the surgical implantation in infants is not amenable to transvenous lead placement, it was necessary to choose from epicardial, subcutaneous and pericardial ICD systems. However, many of these systems are associated with high rates of late complications. Lead fracture, insulation breakage, migration, buckling or crinkling of the patch lead and constrictive pericarditis have been reported as the most common lead-related complications. An increase in the defibrillation threshold is another issue that must be considered when using an ICD in a child or infant. Further studies on the outcomes, psychosomatic impact and other specific complications in the pediatric population need to be considered. The clinical use of ICDs in infants is still limited. Therefore, it is important to have many surgical options available so that the treatment can be custom-tailored to suit individual patients. PMID:24154922

  4. Ambient temperature and activation of implantable cardioverter defibrillators.

    PubMed

    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.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26512151

  6. Interference from a hand held radiofrequency remote control causing discharge of an implantable defibrillator.

    PubMed

    Man, K C; Davidson, T; Langberg, J J; Morady, F; Kalbfleisch, S J

    1993-08-01

    A 46-year-old man with a history of sustained monomorphic ventricular tachycardia underwent an implantation of a third generation multiprogrammable implantable cardioverter defibrillator. One year post implant, while manipulating a remote control to a radiofrequency modulated toy car, the patient experienced a defibrillator discharge not preceded by an arrhythmia prodrome. Subsequent interrogation of the defibrillator revealed that a 34-joule shock had been delivered and had been preceded by RR intervals ranging from 141-406 msec, consistent with sensing lead noise. The remote control utilizes a 12-volt battery and has a carrier frequency of 75.95 MHz and a modulating frequency of 50 Hz. Evaluation of the remote control and defibrillator interaction revealed that the remote control was able to trigger tachyarrhythmia sensing and reproduce the clinical episode. Interference was present only when the remote control was within 8 cm of the pulse generator and at specific angles relative to the device and only when the antenna length was > 45 cm. Interference was eliminated when a ground wire was attached to the antenna and when an aluminium shield was placed between the pulse generator and the remote control. This case report suggests that patients with third generation multiprogrammable defibrillators should be cautioned against close contact with potential sources of electromagnetic interference, such as remote control units.

  7. 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, individuals…

  8. [Tachycardia detection in implantable cardioverter-defibrillators by Sorin/LivaNova : Algorithms, pearls and pitfalls].

    PubMed

    Kolb, Christof; Ocklenburg, Rolf

    2016-09-01

    For physicians involved in the treatment of patients with implantable cardioverter-defibrillators (ICDs) the knowledge of tachycardia detection algorithms is of paramount importance. This knowledge is essential for adequate device selection during de-novo implantation, ICD replacement, and for troubleshooting during follow-up. This review describes tachycardia detection algorithms incorporated in ICDs by Sorin/LivaNova and analyses their strengths and weaknesses.

  9. [Tachycardia detection in implantable cardioverter-defibrillators by Sorin/LivaNova : Algorithms, pearls and pitfalls].

    PubMed

    Kolb, Christof; Ocklenburg, Rolf

    2016-09-01

    For physicians involved in the treatment of patients with implantable cardioverter-defibrillators (ICDs) the knowledge of tachycardia detection algorithms is of paramount importance. This knowledge is essential for adequate device selection during de-novo implantation, ICD replacement, and for troubleshooting during follow-up. This review describes tachycardia detection algorithms incorporated in ICDs by Sorin/LivaNova and analyses their strengths and weaknesses. PMID:27605232

  10. Longevity of implantable cardioverter defibrillators: a comparison among manufacturers and over time

    PubMed Central

    von Gunten, Simon; Schaer, Beat A.; Yap, Sing-Chien; Szili-Torok, Tamas; Kühne, Michael; Sticherling, Christian; Osswald, Stefan; Theuns, Dominic A.M.J.

    2016-01-01

    Aims Longevity of implantable cardioverter defibrillators (ICDs) is crucial for patients and healthcare systems as replacements impact on infection rates and cost-effectiveness. Aim was to determine longevity using very large databases of two teaching hospitals with a high number of replacements and a rather homogeneous distribution among manufacturers. Methods and results The study population consists of all patients in whom an ICD was inserted in. All ICD manufacturers operating in Switzerland and the Netherlands and all implanted ICDs were included. Implantable cardioverter defibrillator replacements due to normal battery depletion were considered events, and other replacements were censored. Longevity was assessed depending on manufacturers, pacing mode, implant before/after 2006, and all parameters combined. We analysed data from 3436 patients in whom 4881 ICDs [44.2% VVI-ICDs, 27.4% DDD-ICDs, 26.3% cardiac resynchronization therapy (CRT)-ICDs, 2.0% subcutaneous ICDs] were implanted. The four major manufacturers had implant shares between 18.4 and 31.5%. Replacement due to battery depletion (27.4%) was performed for 1339 ICDs. Patient survival at 5 years was 80.1%. Longevity at 5 years improved in contemporary compared with elderly ICDs [63.9–80.6% across all ICDs, of 73.7–92.1% in VVIs, 58.2–76.1% in DDDs, and of 47.1–66.3% in CRT defibrillators, all P value < 0.05]. Remarkable differences were seen among manufacturers, and those with better performance in elderly ICDs were not those with better performance in contemporary ones. Conclusion Implantable cardioverter defibrillator longevity increased in contemporary models independent of manufacturer and pacing mode. Still, significant differences exist among manufacturers. These results might impact on device selection. PMID:26609076

  11. 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. PMID:27576695

  12. Appropriateness of sling immobilization to prevent lead displacement after pacemaker/implantable cardioverter-defibrillator implantation.

    PubMed

    Naffe, Aster; Iype, Mini; Easo, Mini; McLeroy, Sandra Dejong; Pinaga, Kelli; Vish, Nancy; Wheelan, Kevin; Franklin, Jay; Adams, Jenny

    2009-01-01

    After pacemaker/implantable cardioverter-defibrillator (pacemaker/ICD) implantation, patients are often required to immobilize the affected arm with a sling to minimize the risk of lead displacement. We examined whether performing a resistive range-of-motion exercise protocol after pacemaker/ICD surgery would result in lead displacement and, therefore, whether sling immobilization and activity restrictions are justified. Ten subjects who had undergone pacemaker/ICD surgery performed four individual resistive range-of-motion exercises (three sets of 10 repetitions for each: one warm-up set without weight and two sets with a 1- or 2-pound hand weight) with the affected arm prior to hospital discharge. For each subject, an electrophysiology nurse specialist used a noninvasive device programmer to evaluate surgical lead placement before and after the exercises. As an adjunct to the study, we queried clinicians at 48 US hospitals about sling immobilization and activity restrictions after pacemaker/ICD implantation at their institutions. No lead displacement occurred after the weightlifting exercises were performed. Based on these results in a small group of patients, it appears that requiring the use of a joint immobilization sling is overly restrictive, promotes fear, and hinders recovery. We encourage the development of consistent discharge instructions that will promote early mobility and a safe and rapid return to normal activities.

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

    PubMed

    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.

  14. 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

  15. New Zealand primary implantable cardioverter defibrillator implantation and biventricular pacing guidelines.

    PubMed

    Smith, Warren

    2010-02-19

    Primary implantation of an implantable Cardioverter Defibrillator (ICD) is recommended for patients with ischaemic or non-ischaemic cardiomyopathy present for at least 3 months, with ejection fraction (EF) = or <30% measured = or >3 months after optimal heart failure treatment. Patients should be on maximal heart failure treatment as tolerated for = or >3 and preferably 6 months, and in New York Heart Association (NYHA) Class II or III. They should be = or >3 months remote from any revascularisation procedure or have no clinical symptoms or findings that would make them a candidate for revascularisation. There should be no associated disease reducing survival <18 months. Biventricular pacing is recommended for patients with an EF = or <35% after = or >6 weeks of optimal heart failure treatment, whose QRS duration is >149 ms or is 120-149 ms with two additional criteria for dyssynchrony (aortic pre-ejection delay >140 ms, interventricular mechanical delay >40 ms or delayed activation of the posterolateral left ventricular wall). They should be NYHA Class III, have had no major cardiovascular event in the prior 6 weeks and be in sinus rhythm. There should be no major comorbidity reducing survival <18 months or seriously impairing quality of life.

  16. Questions to Ask Your Doctor--Implantable Cardioverter Defibrillator (ICD)

    MedlinePlus

    ... implanted to restore normal heart rhythm and prevent sudden cardiac death. To help you understand what it does and how it may affect you or your family member before and after implantation, ask your doctor or healthcare team any ...

  17. Isorhythmic dissociation with smart sensing in a dual-chamber implantable cardioverter defibrillator.

    PubMed

    Strohmer, Bernhard

    2006-07-01

    Isorhythmic dissociation is an uncommon but clinically important finding in a patient implanted with a dual chamber cardioverter defibrillator (ICD) capable of SmartSensing. The surface ECG mimicked a malfunction of the pacemaker that was related to the concomitant hemodynamic deterioration. Device interrogation revealed dissociation of the intrinsic junctional and the pacemaker rhythm, which appeared at similar rates. Careful analysis of intracardiac electrograms and marker channel annotations helped to unravel the limitations for physiologic pacing.

  18. Sensing failure in a tiered therapy implantable cardioverter defibrillator: role of auto adjustable gain.

    PubMed

    Wase, A; Natale, A; Dhala, A A; Deshpande, S; Sra, J S; Blanck, Z; Maglio, C; Jazayeri, M R; Akhtar, M

    1995-06-01

    Implantable cardioverter defibrillators have an established role in the management of life-threatening tachyarrhythmias. These devices use sophisticated sensing circuitry to detect and promptly treat a vast majority of these arrhythmias. However, they are not foolproof. We report one case where the device failed to sense every other QRS complex during induced ventricular fibrillation due to marked electrical alterans. Thus, undersensing can be a potentially fatal problem despite the use of auto adjustable gain. PMID:7659589

  19. Overview of implantable cardioverter defibrillator and cardiac resynchronisation therapy in heart failure management

    PubMed Central

    Chia, Pow-Li; Foo, David

    2016-01-01

    Clinical trials have established the benefits of implantable cardioverter defibrillators (ICDs) and cardiac resynchronisation therapy (CRT) in the treatment of heart failure patients. As adjuncts to guideline-directed medical therapy, ICDs confer mortality benefits from sudden cardiac arrest, while CRT reduces mortality, hospitalisation rates and improves functional capacity. This review discusses the use of ICDs and CRT devices in heart failure management, outlining the evidence supporting their use, indications and contraindications. PMID:27440409

  20. 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

  1. An updated review of implantable cardioverter/defibrillators, induced anxiety, and quality of life.

    PubMed

    Bostwick, J Michael; Sola, Christopher L

    2011-01-01

    Despite overall favorable acceptance of implantable cardioverter-defibrillators (ICDs), patients may experience discharges as frightening and painful. The authors reviewed ICD-induced psychopathology in 2005. During the past 2 years the number of studies examining psychopathology and quality of life after ICD implantation has increased dramatically, warranting this update of that review. Variables assessed have included recipient age, gender, social support network, perception of control and predictability of shocks, and personality style. Now the picture of what is known is, if anything, cloudier than it was 2 years ago, with little definitive and much contradictory data emerging in most of these categories. PMID:21109213

  2. Implantation of a defibrillator in a patient with an upper airway stimulation device.

    PubMed

    Ong, Adrian A; O'Brien, Terrence X; Nguyen, Shaun A; Gillespie, M Boyd

    2016-02-01

    The patient is a 62-year-old man with continuous positive airway pressure-intolerant obstructive sleep apnea who was enrolled in a study for a hypoglossal nerve upper airway stimulation device (UAS). Nearly 2.5 years later, he was admitted to the hospital for unstable angina. Diagnostic workup revealed a prior myocardial infarction, an ejection fraction of 30% on maximal medical therapy, and episodes of nonsustained ventricular tachycardia. During hospitalization, the patient received an implantable cardioverter defibrillator (ICD). This is the first reported case of simultaneous use of a UAS and an ICD, and we report no untoward device interference between the two implantable devices.

  3. 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.

  4. A plea for delivery of high-voltage shocks during implantable cardioverter-defibrillator replacement or system upgrade.

    PubMed

    Sticherling, Christian; Schaer, Beat; Kühne, Michael; Osswald, Stefan

    2012-01-01

    We report the case of a faulty lead that led to failure to defibrillate during defibrillation threshold testing at the time of elective generator replacement. Standard lead measurements failed to detect the malfunction. Many centres perform neither defibrillation threshold testing nor commanded high-energy shock delivery. Even changes in the position of the lead in relation to the generator may cause problems that will go undetected without high-voltage shock delivery. We therefore caution against the wholesale abandonment of high-voltage shock testing in patients with pre-existing implanted leads.

  5. A plea for delivery of high-voltage shocks during implantable cardioverter-defibrillator replacement or system upgrade.

    PubMed

    Sticherling, Christian; Schaer, Beat; Kühne, Michael; Osswald, Stefan

    2012-01-01

    We report the case of a faulty lead that led to failure to defibrillate during defibrillation threshold testing at the time of elective generator replacement. Standard lead measurements failed to detect the malfunction. Many centres perform neither defibrillation threshold testing nor commanded high-energy shock delivery. Even changes in the position of the lead in relation to the generator may cause problems that will go undetected without high-voltage shock delivery. We therefore caution against the wholesale abandonment of high-voltage shock testing in patients with pre-existing implanted leads. PMID:22498180

  6. 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.

  7. Intrapericardial and retrocardial implantation of implantable cardioverter-defibrillator lead in a child with type 3 long QT syndrome.

    PubMed

    Ichikawa, Yasuhiro; Iwamoto, Mari; Yanagi, Sadamitsu; Masuda, Munetaka

    2011-10-01

    A 6-year-old girl with type 3 long QT syndrome was safely and successfully implanted with an implantable cardioverter-defibrillator (ICD) system. Prior to implantation, she had experienced uncontrollable life-threatening arrhythmia in spite of high-dose administration of mexiletine. An ICD coil lead for transvenous use was placed in the intrapericardial and retrocardial space and was connected to a generator placed in front of the posterior sheath of the right abdominal rectal muscle. Administration of a beta-blocker in addition to atrial pacing almost completely eliminated the patient's life-threatening arrhythmia attacks. Intrapericardial and retrocardial implantation of ICD coil leads might be useful for children. PMID:21818650

  8. Pacemakers and Implantable Defibrillators - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Somali) Bilingual PDF Health Information Translations Spanish (español) Marcapasos y desfibrilador implantable Ukrainian (Українська) Pacemaker Електрокардіостимулятор - Українська ( ...

  9. Association of Physician Certification and Outcomes Among Patients Receiving an Implantable Cardioverter-Defibrillator

    PubMed Central

    Curtis, Jeptha P.; Luebbert, Jeffrey J.; Wang, Yongfei; Rathore, Saif S.; Chen, Jersey; Heidenreich, Paul A.; Hammill, Stephen C.; Lampert, Rachel I.; Krumholz, Harlan M.

    2009-01-01

    Context Allowing nonelectrophysiologists to perform implantable cardioverter-defibrillator (ICD) procedures is controversial. However, it is not known whether outcomes of ICD implantation vary by physician specialty. Objective To determine the association of implanting physician certification with outcomes following ICD implantation. Design, Setting, and Patients Retrospective cohort study using cases submitted to the ICD Registry performed between January 2006 and June 2007. Patients were grouped by the certification status of the implanting physician into mutually exclusive categories: electrophysiologists, nonelectrophysiologist cardiologists, thoracic surgeons, and other specialists. Hierarchical logistic regression models were developed to determine the independent association of physician certification with outcomes. Main Outcome Measures In-hospital procedural complication rates and the proportion of patients meeting criteria for a defibrillator with cardiac resynchronization therapy (CRT-D) who received that device. Results Of 111 293 ICD implantations included in the analysis, 78 857 (70.9%) were performed by electrophysiologists, 24 399 (21.9%) by nonelectrophysiologist cardiologists, 1862 (1.7%) by thoracic surgeons, and 6175 (5.5%) by other specialists. Compared with patients whose ICD was implanted by electrophysiologists, patients whose ICD was implanted by either nonelectrophysiologist cardiologists or thoracic surgeons were at increased risk of complications in both unadjusted (electrophysiologists, 3.5% [2743/78 857]; nonelectrophysiologist cardiologists, 4.0% [970/24 399]; thoracic surgeons, 5.8% [108/1862]; P < .001) and adjusted analyses (relative risk [RR] for nonelectrophysiologist cardiologists, 1.11 [95% confidence interval {CI}, 1.01–1.21]; RR for thoracic surgeons, 1.44 [95% CI, 1.15–1.79]). Among 35 841 patients who met criteria for CRT-D, those whose ICD was implanted by physicians other than electrophysiologists were significantly

  10. Interference between pacemakers/implantable cardioverter defibrillators and video capsule endoscopy

    PubMed Central

    Bandorski, Dirk; Gehron, Johannes; Höltgen, Reinhard

    2013-01-01

    Our Letter to the Editor, related to the article “Small bowel capsule endoscopy in patients with cardiac pacemakers and implantable cardioverter defibrillators: Outcome analysis using telemetry” by Cuschieri et al, comments on some small errors, that slipped into the authors discussions. The given informations concerning the pacemaker- and implantable cardioverter defibrillators modes were inaccurate and differ between the text and the table. Moreover, as 8 of 20 patient’s pacemakers were programmed to VOO or DOO (“interference mode”) and one patient was not monitored by telemetry during capsule endoscopy, 9 of 20 patients (45%) lack the informations of possible interference between capsule endoscopy their implanted device. Another objection refers to the interpretation of an electrocardiogram (figure 1, trace B) presented: in contrast to the author’s opinion the marked spike should be interpreted as an artefact and not as ”undersensing of a fibrillatory wave”. Finally, three comments to cited reviews were not complete respectively not quoted correctly. PMID:23596547

  11. Safety and Cost-Effectiveness of Same-Day Cardiac Resynchronization Therapy and Implantable Cardioverter Defibrillator Implantation.

    PubMed

    Atherton, Gavin; McAloon, Christopher James; Chohan, Bhaveek; Heining, Dominic; Anderson, Benjamin; Barker, Jethro; Randeva, Harpal; Osman, Faizel

    2016-05-01

    Cardiac resynchronization therapy (CRT) and implantable cardioverter defibrillator (ICD) implantation improve morbidity and mortality in selected patients. Many centers still admit patients overnight. We evaluated the safety, feasibility, and cost savings of same-day CRT/ICD device implantation by performing a retrospective study of all consecutive elective CRT/ICD implants at a tertiary center from January 2009 to April 2013. All emergency and/or inpatient cases were excluded. Data were collected on baseline demographics, implantation indication, procedure details, complications (categorized as immediate [≤24 hours], short term [24 hours to 6 weeks], medium term [6 weeks to 4 months], and long term [>4 months]), and mortality (30 day and 1 year). Comparisons were made between those having planned same-day versus overnight stay procedures. A cost analysis was performed to evaluate cost savings of the same-day policy. A total of 491 devices were implanted during this period: 267 were elective (54 planned overnight, 213 planned same-day) of which 229 were CRT pacemakers or CRT defibrillators and 38 ICDs. There were 26 total overall complications (9.7%) with no significant differences between planned same-day versus planned overnight stay cohorts (9.4% vs 11.1%, p = 0.8) and specifically no differences in immediate, short-, medium-, and long-term complications at follow-up. The 30-day and 1-year mortality rates did not differ between the two groups. An overnight stay at our hospital costs $450 (£300); our cost saving during this period was $91,800 (£61,200). Same-day CRT/ICD implantation is safe, feasible, and associated with significant cost savings. It provides significant advantages for patients and health care providers, especially given the current financial climate. PMID:26993428

  12. Ventricular Arrhythmias in Apparently Normal Hearts: Who Needs an Implantable Cardiac Defibrillator?

    PubMed

    Tan, Alex Y; Ellenbogen, Kenneth

    2016-09-01

    Idiopathic ventricular tachycardia is often considered a benign form of ventricular arrhythmia in patients without apparent structural heart disease. However, a subset of patients may develop malignant ventricular arrhythmias and present with syncope and sudden cardiac arrest. Survivors of cardiac arrest are candidates for implantable cardiac defibrillators (ICDs). The indications for ICDs in patients with less than a full-blown cardiac arrest presentation but with electrocardiographically high-risk ectopy features remain uncertain. This article addresses some of the uncertainties and pitfalls in ICD risk stratification in this patient group and explores potential mechanisms for malignant conversion of benign premature ventricular complexes to sustained arrhythmia. PMID:27521094

  13. Ventricular Arrhythmias in Apparently Normal Hearts: Who Needs an Implantable Cardiac Defibrillator?

    PubMed

    Tan, Alex Y; Ellenbogen, Kenneth

    2016-09-01

    Idiopathic ventricular tachycardia is often considered a benign form of ventricular arrhythmia in patients without apparent structural heart disease. However, a subset of patients may develop malignant ventricular arrhythmias and present with syncope and sudden cardiac arrest. Survivors of cardiac arrest are candidates for implantable cardiac defibrillators (ICDs). The indications for ICDs in patients with less than a full-blown cardiac arrest presentation but with electrocardiographically high-risk ectopy features remain uncertain. This article addresses some of the uncertainties and pitfalls in ICD risk stratification in this patient group and explores potential mechanisms for malignant conversion of benign premature ventricular complexes to sustained arrhythmia.

  14. 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.

  15. Tools and strategies for the reduction of inappropriate implantable cardioverter defibrillator shocks.

    PubMed

    Tzeis, Stylianos; Andrikopoulos, George; Kolb, Christof; Vardas, Panos E

    2008-11-01

    Implantable cardioverter defibrillators (ICDs) have been shown to provide a survival benefit in patients at high risk of sudden cardiac death. A major problem associated with ICD therapy is the occurrence of inappropriate shocks which impair patients' quality of life and may also be arrhythmogenic. Despite recent technological advances, the incidence of inappropriate shocks remains high, thus posing a challenge that we have to meet. In the present review we summarise the available tools and the strategies that can be followed in order to reduce inappropriate ICD shocks.

  16. [Shock-induced, but not terminated ventricular tachycardia in a patient with implantable defibrillator].

    PubMed

    Kühlkamp, V; Dörnberger, V; Mermi, J; Mewis, C; Seipel, L

    1996-05-01

    A 62-year-old male patient with coronary artery disease and drug refractory sustained ventricular tachycardia received an implantable cardioverter defibrillator (PRX III, model 1720, CPI) with a transvenous lead system (Endotak, model 0115, CPI) in combination with a subcutaneous array electrode (SQ array, model 049, CPI). The intraoperative defibrillation threshold was 15 J and was confirmed 1 week later at the hospital discharge test. Three months after discharge from hospital the patient reported 5 shocks during moderate physical exertion followed by a tachycardia associated with dizziness which terminated spontaneously. The print out of the stored electrogram showed a supraventricular tachycardia (probably sinus tachycardia) with a heart rate of 154/min which activated the device. Antitachycardia pacing did not terminate the supraventricular tachycardia, and hence shock therapy was delivered. The first shock (34 J) converted the supraventricular tachycardia to a ventricular tachycardia with a heart rate of 178/min, which was not terminated by four consecutive 34 J DC shocks. There was no hint of a device or lead failure. Determination of the defibrillation threshold reconfirmed the 15 J value for termination of ventricular fibrillation. However, neither a 1 J shock nor a 34 J shock terminated a monomorphic sustained ventricular tachycardia (cycle length 340 ms) induced by noninvasive programmed electrical stimulation. The ventricular tachycardia was, however, reproducibly terminate by antitachycardia pacing. It is concluded that an inappropriate high-energy DC shock might induce a sustained ventricular tachycardia. However, a sufficient defibrillation threshold for the termination of ventricular fibrillation does not necessarily mean that a sustained ventricular tachycardia will be terminated by a high-energy DC shock.

  17. Development of a hybrid battery system for an implantable biomedical device, especially a defibrillator/cardioverter (ICD)

    NASA Astrophysics Data System (ADS)

    Drews, Jürgen; Wolf, R.; Fehrmann, G.; Staub, R.

    An implantable defibrillator battery has to provide pulse power capabilities as well as high energy density. Low self-discharge rates are mandatory and a way to check the remaining available capacity is necessary. These requirements are accomplished by a system consisting of a lithium/manganese dioxide 6 V battery, plus a lithium/iodine-cell. The use of a high rate 6 V double-cell design in combination with a high energy density cell reduces the total volume required by the power source within an implantable defibrillator. The design features and performance data of the hybrid system are described.

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

    PubMed Central

    2013-01-01

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

  19. Home monitoring of implantable cardioverter-defibrillators: interpretation reliability of the second-generation “IEGM Online” system

    PubMed Central

    Nägele, Herbert; Lipoldová, Jolana; Oswald, Hanno; Klein, Gunnar; Elvan, Arif; Vester, Ernst; Bauer, Wolfgang; Bondke, Hansjürgen; Reif, Sebastian; Daub, Claudia; Menzel, Frank; Schrader, Jürgen; Zach, Göran

    2015-01-01

    Aims Intracardiac electrograms (IEGMs) are essential for the assessment of implantable cardioverter-defibrillator (ICD) function. The Biotronik Home Monitoring systems transmit an ‘IEGM Online’ that is shorter than the full-length programmer IEGM due to technical constrains. The aim of this study was to evaluate the accuracy of the physician's classification of the underlying rhythm based on the second-generation IEGM Online. Methods and results In total, 1533 patients treated with single- and dual-chamber ICDs and cardiac resynchronization therapy defibrillators were enrolled at 67 investigational sites and followed for 15 months. The investigators classified the rhythm shown in IEGM Online as ventricular tachycardia, ventricular fibrillation, atrial fibrillation, other supraventricular tachyarrhythmia, oversensing due to lead failure, T-wave oversensing, or other rhythm. At the next in-office follow-up, the investigators classified independently the rhythm seen in the corresponding programmer IEGM. The two rhythm classifications were compared thereafter. Both IEGM Online and programmer IEGM were available in 2099 arrhythmic or oversensing events, of which 146 (7.0%) were classified as other rhythm or artefacts and were excluded as inconclusive or atypical. The remaining 1953 events, affecting 352 patients (23.0%), were classified correctly in 1803 cases (92.3%). The accuracy of rough rhythm classification as ventricular, supraventricular, or oversensing was 97.2%. Conclusion The Lumax and IEGM Online HD Evaluation study demonstrates that remote IEGM analysis is reasonably accurate in a remote monitoring system that transmits shorter IEGM than the full-length programmer IEGM for the sake of frequent, fully automatic data transmission. PMID:25567067

  20. Removal of the broken part of implantable cardioverter-defibrillator's electrode causing pulmonary embolism via femoral vein.

    PubMed

    Zencir, Cemil; Selvi, Mithat; Elbi, Huseyin; Cetin, Mustafa; Gungor, Hasan; Akgullu, Cagdas; Badak, Muharrem Ismail

    2015-12-01

    A 66-year-old patient with idiopathic dilated cardiomyopathy underwent transvenous extraction of an implantable cardioverter-defibrillator. The distal part of the electrode was broken during manual traction through the left subclavian vein. In the present case, we showed a rare complication of transvenous lead extraction and its management. PMID:26995444

  1. Electrical storm in patients with implantable cardioverter-defibrillators: can it be forecast?

    PubMed

    Emkanjoo, Zahra; Alihasani, Narges; Alizadeh, Abolfath; Tayyebi, Mohammad; Bonakdar, Hamid; Barakpour, Hamid; Sadr-Ameli, Mohammad Ali

    2009-01-01

    The aim of this retrospective study was to determine the prevalence and predictors of electrical storm in 227 patients who had received implantable cardioverter-defibrillators (ICDs) and had been monitored for 31.7 +/- 15.6 months. Of these, 174 (77%) were men. The mean age was 55.8 +/- 15.5 years (range, 20-85 yr), and the mean left ventricular ejection fraction (LVEF) was 0.30 +/- 0.14. One hundred forty-six of the patients (64%) had underlying coronary artery disease. Cardioverter-defibrillators were implanted for secondary (80%) and primary (20%) prevention. Of the 227 patients, 117 (52%) experienced events that required ICD therapy. Thirty patients (mean age, 57.26 +/- 14.3 yr) had > or = 3 episodes requiring ICD therapy in a 24-hour period and were considered to have electrical storm. The mean number of events was 12.75 +/- 15 per patient. Arrhythmia-clustering occurred an average of 6.1 +/- 6.7 months after ICD implantation. Clinical variables with the most significant association with electrical storm were low LVEF (P = 0.04; hazard ratio of 0.261, and 95% confidence interval of 0.08-0.86) and higher use of class IA antiarrhythmic drugs (P = 0.018, hazard ratio of 3.84, and 95% confidence interval of 1.47-10.05). Amiodarone treatment and use of beta-blockers were not significant predictors when subjected to multivariate analysis. We conclude that electrical storm is most likely to occur in patients with lower LVEF and that the use of Class IA antiarrhythmic drugs is a risk factor.

  2. Changing Views: Safety and Efficacy of Implantable Cardioverter- Defibrillator Therapy in Athletes.

    PubMed

    Pavlů, Luděk; Hutyra, Martin; Táborský, Miloš

    2015-11-01

    The implantable cardioverter-defibrillator (ICD) is highly effective in reducing sudden death from ventricular tachyarrhythmia among high-risk cardiac patients. Conventional advice given to patients with ICD is to avoid physical activity more strenuous than playing golf or bowling. This recommendation is given due to a theoretical risk of arrhythmia precipitation, and thus increased risk of death due to failure to defibrillate, injury resulting from loss of control caused by arrhythmia-related syncope or shock, and also due to sport related direct damage to the ICD system. Recent prospective data from an international registry involving 372 athletes with ICDs in situ and actively participating in sports has been published. This indicates that, although physical activity resulted in an increased number of shocks compared to rest, there was no significant difference between intensive physical activity and any other activity (10% vs. 8%, p=0.34) in frequency of shocks. Furthermore, over a median follow-up period of 31 months (21-46 months), in the period of sports activity and 2 hour rest directly after there were no occurrences of death, resuscitated arrest or arrhythmia, or shock-related injury. This data is likely to start a shift in every-day clinical decision-making leading to revision of the high level of precautions imposed on the rapidly enlarging ICD recipient population. PMID:26849548

  3. [Twiddler-Syndrome in a subpectoral implanted unipolar cardioverter-defibrillator].

    PubMed

    Mewis, C; Kühlkamp, V; Dörnberger, V; Kalighi, K; Seipel, L

    1998-01-01

    Twiddler's syndrome is a rare complication in patients with pacemakers. We report this very rare syndrome in a patient with pectoral implanted unipolar cardioverter defibrillator. This syndrome was detected because the patient presented in the 3 month routine visit an exitblock with an increased pacing impedance. The defibrillation threshold remained unchanged. The chest x-ray revealed an inferolaterally migrated generator with a multiply rotated lead. The intraoperative exploration showed a generator which was rotated nine-fold around its longitudinal axis with a multiple twisted unipolar lead. The lead was substituted and the aggregate fixed with a suture to the underlying muscle fascia. An atrophy of the pectoralis muscle was found in this patient which previously resulted from a long hospital stay. This atrophy was identified as a possible risk factor for the development of Twiddler's syndrome. This report illustrates that Twiddler's syndrome, a rare complication in patients with pectoral ICD, may become a significant problem in these patients as it is for pacemaker patients but with more serious possible consequences.

  4. 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.

  5. Exercise and competitive sports in patients with an implantable cardioverter-defibrillator.

    PubMed

    Heidbuchel, Hein; Carré, Francois

    2014-11-21

    Implantable cardioverter-defibrillators (ICDs) prevent sudden arrhythmic death in patients with different arrhythmogenic cardiac diseases. Because intense physical activity may trigger ventricular arrhythmias and may favour inappropriate shock delivery that impacts quality of life, current international recommendations only give clearance for moderate leisure-time physical activity to patients with an ICD. Hence, athletes are deemed non-eligible to compete with their ICD. The rationale for the current restriction from competitive sports is discussed in this review, as well as new insights that may alter these recommendations for certain sports participants in the foreseeable future. This review provides guidance for the choice of a durable lead and device system, careful programming tailored to the characteristics of the patient's physiological and pathological heart rhythms, instalment of preventive bradycardic medication, and guided rehabilitation with psychological counselling, allowing a maximum of benefit and a minimum of harm for physically active ICD patients.

  6. 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.

  7. [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.

  8. Living with an implantable cardiac defibrillator: a model of chronic uncertainty.

    PubMed

    Carroll, Sandra L; McGillion, Michael; Arthur, Heather M

    2014-01-01

    Over the last two decades, the number of patients receiving implantable cardiac defibrillators (ICDs) for the prevention of sudden cardiac death has grown significantly. This growth is largely the result of broadened indication for ICD use because of the success of trials demonstrating efficacy. Early ICD indication centered on secondary prevention, which then advanced to primary prevention in high-risk patients. Nurses delivering care to these patients not only manage this complex technology but also patients' uncertainty about their survival and related psychosocial adjustment to receiving an ICD. To inform practice, theoretical models such as Mishel's (1988) uncertainty in illness model provide insight into such acute phases of illness. This article proposes expansion of the uncertainty in illness model to advance knowledge in this field for nurses caring for patients with ICD.

  9. [Practical questions around individual with a pacemaker or an implantable cardioverter defibrillator].

    PubMed

    Manaouil, Cécile; Fantoni, Sophie; Montpellier, Dominique; Tordjman, Eric; Jarde, Olivier

    2012-07-01

    An individual with a pacemaker can ask his GP for information about potential problems associated with the device. Should a pacemaker continue to be used by end-of-life patients? Should a pacemaker be stopped in a limited care situation? What precautions should be taken when treating a patient with a pacemaker? Pacemakers and implantable defibrillators are sensitive to electromagnetic interference (EMI). Medically, MRIs are theoretically contraindicated, even though examinations could be performed without a major problem, and special precautions should be taken when using an electrosurgical cutter or radiotherapy. In case of death, a doctor or embalmer must remove the patient's pacemaker due to its risk of explosion during cremation. Doctors who sign cremation forms have a legal obligation to provide such information. It may affect an employee's ability to work. Are there some professions that are not well suited for individuals with a pacemaker? PMID:22138293

  10. Predictors and Clinical Impact of Inappropriate Implantable Cardioverter-Defibrillator Shocks in Korean Patients

    PubMed Central

    Yang, Jeong Hoon; Byeon, Kyeongmin; Yim, Hye Ran; Park, Jung Wae; Park, Seung-Jung; Huh, June; Kim, June Soo

    2012-01-01

    Limited data are available on inappropriate shocks in Korean patients implanted with an implantable cardioverter-defibrillator (ICD). We investigated the impact of inappropriate shocks on clinical outcomes. This retrospective, single-center study included 148 patients treated between October 1999 and June 2011. The primary outcome was a composite event of all-cause mortality or hospitalization for any cardiac reason. The median follow-up duration was 29 months (interquartile range: 8 to 53). One or more inappropriate shocks occurred in 34 (23.0%) patients. A history of atrial fibrillation was the only independent predictor of inappropriate shock (hazard ratio [HR]: 4.16, 95% confidence interval [CI]: 1.89-9.15, P < 0.001). Atrial fibrillation was the most common cause of inappropriate shock (67.7%), followed by supraventricular tachycardia (23.5%), and abnormal sensing (8.8%). A composite event of all-cause mortality or hospitalizations for any cardiac reason during follow-up was not significantly different between patients with or without inappropriate shock (inappropriate shock vs no inappropriate shock: 35.3% vs 35.4%, adjusted HR: 1.06, 95% CI: 0.49-2.29, P = 0.877). Inappropriate shocks do not affect clinical outcomes in patients implanted with an ICD, although the incidence of inappropriate shocks is high. PMID:22690092

  11. 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

  12. Rhetorical strategies used in the reporting of implantable defibrillator primary prevention trials.

    PubMed

    Wilson, John R

    2011-06-15

    Previous studies have suggest that the authors of randomized trial reports frequently use rhetorical strategies, such as framing, the use of ratios rather than absolute values to report results, and underreporting of complications, to convince readers of treatment efficacy. The objective of this study was to determine if such rhetorical strategies were used in the publication of implantable-cardioverter defibrillator (ICD) primary prevention trials. Medline and the Cochrane Central Register of Controlled Trials were searched for all publications that described ICD primary prevention trials and that involved >100 subjects. Each publication was analyzed for evidence of message framing, the exclusive use of ratios to report outcomes, underreporting of ICD complications, and interpretation bias favoring ICD therapy. Ten publications were identified. Introductory remarks in 8 of the 10 publications cited the evaluation of ICD benefits as the sole objective and mentioned only background studies that supported ICD efficacy, suggesting message framing in support of ICD efficacy. Five publications provided no specific information about the frequency of unsuccessful ICD implantations, and 8 publications provided incomplete or no information about implantation and postimplantation complications. ICD complications were not mentioned in the discussion sections of 9 publications, and none of the publications included a comprehensive comparison of ICD benefits versus risks, consistent with interpretation bias. Ratios and statistically insignificant data were not used to emphasize ICD benefits. In conclusion, message framing, underreporting of ICD complications, and interpretation bias were used to emphasize ICD efficacy in the reporting of ICD primary prevention trials.

  13. 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

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

    PubMed

    Raman, Ajay Sundara; Shabari, Farshad Raissi; Kar, Biswajit; Loyalka, Pranav; Hariharan, Ramesh

    2016-04-01

    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.

  15. The prevalence of methicillin resistant organisms among pacemaker and defibrillator implant recipients

    PubMed Central

    Rodriguez, David J; Afzal, Aisha; Evonich, Rudolph; Haines, David E

    2012-01-01

    Introduction Pacemaker and defibrillator infections are an uncommon, but catastrophic complication of device implantation. The present study examined the prevalence of device-related infections, the patterns of antibiotic resistance, and the presence of methicillin resistant staphylococcus aureus (MRSA) nares colonization in device implant recipients. Methods Two protocols were employed using a retrospective and a prospective analysis. A retrospective chart review of 218 patients with suspected device infection from 1/2000 to 1/2011 was performed. Demographics, infection rates, and patterns of antibiotic resistance were compared. The prospective analysis enrolled one hundred eighty two patients undergoing device implantations or generator replacements. The nares were swabbed and analyzed for the presence of staphylococcus aureus, and tested for methicillin sensitivity. Results Over a period of ten years, 12,771 device implants/generator changes/system revisions were performed, with an infection rate of 1.2%. Methicillin resistance (MR) was identified in 98/218 (44.9%) of patients. Those with MR infection had more diabetes and cardiomyopathy. There was no significant increase in methicillin resistance over time (p=0.30). Our prospective analysis included 110 men. A total of 32 patients (17.6%) had positive cultures for SA: 6.6% with MRSA. Patients positive for MRSA nares colonization had a statistically significant greater length of hospital stay 8.5 days (mean) versus 4.4 days (P=0.049). Conclusions Methicillin resistant organisms appear to be emerging and persistent pathogens in device implants. The screening of MRSA colonization may identify new populations at risk. Further studies and analysis are needed to determine the cost effectiveness of a screening protocol. PMID:22720201

  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. Home monitoring report from a single lead Lumax DX implantable cardioverter defibrillator: New observations in a new system.

    PubMed

    Konstantino, Yuval; Kleiman, Alex; Amit, Guy

    2016-06-01

    A 56-year-old man underwent a single lead Lumax 640 DX implantable cardioverter defibrillator implantation for primary prevention of sudden cardiac death. A DX system consists of a single lead, which provides atrial as well as ventricular electrograms, and enhances atrial arrhythmia detection. Three months after the implantation, high-frequency episodes were detected on the far field and the atrial channels, but not on the bipolar right ventricular channel; these were classified as atrial tachycardia. In the present report, we discussed the unusual pattern of the artifacts that was related to an electromagnetic interference detected by the novel DX system. PMID:27354868

  18. Driving restrictions advised by midwestern cardiologists implanting cardioverter defibrillators: present practices, criteria utilized, and compatibility with existing state laws.

    PubMed

    DiCarlo, L A; Winston, S A; Honoway, S; Reed, P

    1992-08-01

    Although some patients remain at risk of losing physical control or collapsing after implantation of a cardioverter defibrillator for sustained ventricular arrhythmias, little is known about restrictions advised by arrhythmia specialists to patients with implanted devices concerning physical activities such as driving. In this study, all of the 58 cardiologists implanting cardioverter defibrillators in three contiguous midwestern states were surveyed to determine present practices and the compatibility of these practices with existing state law. Of the 51 respondents (88%), 27 cardiologists (53%) advised only those implanted patients who had had arrhythmia-induced presyncope or physical collapse to cease driving. Twenty two of the remaining cardiologists (43%) advised all implanted patients to cease driving, whereas two cardiologists (4%) never advised any implanted patient to restrict driving. Permanent driving abstinence was advised by seven of the responding cardiologists (14%), while temporary driving abstinence for periods of 2-12 months (mean 6 +/- 3 months) was recommended by the remaining 42 respondents (82%) who advised against driving. The criteria utilized, driving restrictions advised, and durations advised for driving restrictions were not uniform in any of the 13 surveyed university and nonaffiliated cardiology practices with greater than or equal to 2 implanting cardiologists. Overall, 38 cardiologists (74%) advised against driving and recommended durations that equaled or exceed their state's minimum legal requirements, although only 27 of the 51 cardiologists (53%) based their practice upon knowledge of their state's driving laws. The results of this survey suggest that the majority of cardiologists who implant cardioverter defibrillators advise their patients against driving postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. 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

  20. Modeling Defibrillation of the Heart: Approaches and Insights

    PubMed Central

    Trayanova, Natalia; Constantino, Jason; Ashihara, Takashi; Plank, Gernot

    2012-01-01

    Cardiac defibrillation, as accomplished nowadays by automatic, implantable devices (ICDs), constitutes the most important means of combating sudden cardiac death. While ICD therapy has proved to be efficient and reliable, defibrillation is a traumatic experience. Thus, research on defibrillation mechanisms, particularly aimed at lowering defibrillation voltage, remains an important topic. Advancing our understanding towards a full appreciation of the mechanisms by which a shock interacts with the heart is the most promising approach to achieve this goal. The aim of this paper is to assess the current state-of-the-art in ventricular defibrillation modeling, focusing on both numerical modeling approaches and major insights that have been obtained using defibrillation models, primarily those of realistic ventricular geometry. The paper showcases the contributions that modeling and simulation have made to our understanding of the defibrillation process. The review thus provides an example of biophysically based computational modeling of the heart (i.e., cardiac defibrillation) that has advanced the understanding of cardiac electrophysiological interaction at the organ level and has the potential to contribute to the betterment of the clinical practice of defibrillation. PMID:22273793

  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. A single implantable cardioverter-defibrillator shock unmasking an electrical storm of 389 ventricular tachycardia episodes triggering device therapies.

    PubMed

    Arias, Miguel A; Valverde, Irene; Puchol, Alberto; Castellanos, Eduardo; Rodríguez-Padial, Luis; Sánchez, Ana M; Alvarez-Temiño, María; Palomino, Miguel

    2008-11-01

    We describe the case of a patient with ischemic cardiomyopathy who presented the first implantable cardioverter-defibrillator (ICD) shock approximately 5 months after implantation. Device interrogation surprisingly revealed the occurrence of 389 ventricular tachyarrhythmia episodes terminated by asymptomatic antitachycardia pacing (ATP) except for the episode requiring shock. The present case of electrical storm highlights how contemporary tiered ATP schemes constitute a valuable but underused form of termination for ventricular tachyarrhythmias in ICD patients, reducing the number of painful shocks and their adverse consequences.

  3. Pacemakers, implantable cardioverter/defibrillators, and extracorporeal shockwave lithotripsy: evidence-based guidelines for the modern era.

    PubMed

    Platonov, Michael A; Gillis, Anne M; Kavanagh, Katherine M

    2008-02-01

    Early work examining interactions between extracorporeal shockwave lithotripsy (SWL) and implantable pacemakers or implantable cardioverter/defibrillators suggested that shockwave oversensing may result in inappropriate suppression of pacing, delivery of antitachycardia pacing therapy, delivery of inappropriate shock therapy, or outright damage to such devices. In the absence of national guidelines, those provided by manufacturers are nonuniform and practice patterns vary between centers. Improvements in SWL energy delivery as well as in device shielding and discrimination technologies have demonstrated improved safety data in recent years. We review these advances in both technologies as well as the most recent data to construct practice guidelines for the modern era.

  4. Mexiletine as an adjunctive therapy to amiodarone reduces the frequency of ventricular tachyarrhythmia events in patients with an implantable defibrillator.

    PubMed

    Gao, Dongsheng; Van Herendael, Hugo; Alshengeiti, Lamia; Dorian, Paul; Mangat, Iqwal; Korley, Victoria; Ahmad, Kamran; Golovchiner, Gregory; Aves, Theresa; Pinter, Arnold

    2013-08-01

    The most effective pharmacological management of frequent ventricular tachyarrhythmia events in patients with an implantable defibrillator who failed or did not tolerate amiodarone is unknown. The aim of this retrospective cohort study was to assess the efficacy and tolerability of mexiletine in such patients. The patients served as self-controls. The number of treated ventricular tachyarrhythmia episodes (primary outcome); mortality, shocks from the defibrillator, and electrical storm events (secondary outcomes) during mexiletine therapy was compared with a matched duration of observation just before initiating mexiletine in 29 patients who were treated with a median dose of 300 mg/d of mexiletine and were followed for a median of 12 months. None of the patients had to stop mexiletine due to side effect. There was a significant reduction in the incidence of ventricular tachycardia/fibrillation episodes (median 2 vs. 12 events, P = 0.001) and shocks (median 0 vs. 2 events, P = 0.003) in the first 3 months of treatment, but long-term efficacy was only observed among patients who continued amiodarone therapy. In conclusion, mexiletine, when added to amiodarone in case of amiodarone inefficacy, reduces ventricular tachycardia/fibrillation events and appropriate therapies in patients with an implantable cardioverter defibrillator. A randomized trial should validate the efficacy and safety of mexiletine as an adjunctive therapy to amiodarone. PMID:23609328

  5. 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.

  6. Lithium-manganese dioxide cells for implantable defibrillator devices-Discharge voltage models

    NASA Astrophysics Data System (ADS)

    Root, Michael J.

    The discharge potential behavior of lithium-manganese dioxide cells designed for implantable cardiac defibrillators was characterized as a function of extent of cell depletion for tests designed to discharge the cells for times between 1 and 7 years. The discharge potential curves may be separated into two segments from 0 ≤ x ≤ ∼0.51 and ∼0.51 ≤ x ≤ 1.00, where x is the dimensionless extent of discharge referenced to the rated cell capacity. The discharge potentials conform to Tafel kinetics in each segment. This behavior allows the discharge potential curves to be predicted for an arbitrary discharge load and long term discharge performance may be predicted from short term test results. The discharge potentials may subsequently be modeled by fitting the discharge curves to empirical functions like polynomials and Padé approximants. A function based on the Nernst equation that includes a term accounting for nonideal interactions between lithium ions and the cathode host material, such as the Redlich-Kister relationship, also may be used to predict discharge behavior.

  7. Quality of Life in Patients with an Implantable Cardioverter Defibrillator: A Systematic Review.

    PubMed

    Tomzik, Juliane; Koltermann, Katharina C; Zabel, Markus; Willich, Stefan N; Reinhold, Thomas

    2015-01-01

    Despite the indisputable mortality advantages of implantable cardioverter defibrillators (ICDs), no consensus exists regarding their impact on quality of life (QoL). This systematic review investigates differences in QoL between patients with ICDs and controls. We systematically searched the MEDLINE, EMBASE, Cochrane, Web of Science, and PsychINFO databases. Articles were included if they were published after the year 2000 and reported on original studies with a control group. Five randomized controlled trials with a total of 5,138 patients and 10 observational studies with a total of 1,513 patients met the inclusion criteria. Nine studies found comparable QoL for ICD recipients and patients in the control groups, three studies found an increased QoL for ICD patients, and three studies found a decreased QoL for ICD patients. The question of whether QoL relates to ICD therapy cannot be answered conclusively due to the heterogeneity of the existing studies. Lower QoL was apparent among patients with an ICD who experienced several device discharges. Medical staff should be particularly aware of the signs of both psychological and physical disorders in these patients. Further investigations on QoL in ICD patients are desirable, but ethical reasons restrict the conduct of randomized trials. PMID:26664905

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

    PubMed

    Nordbeck, Peter; Ertl, Georg; Ritter, Oliver

    2015-06-21

    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

  9. 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. PMID:27568872

  10. Quality of Life in Patients with an Implantable Cardioverter Defibrillator: A Systematic Review

    PubMed Central

    Tomzik, Juliane; Koltermann, Katharina C.; Zabel, Markus; Willich, Stefan N.; Reinhold, Thomas

    2015-01-01

    Despite the indisputable mortality advantages of implantable cardioverter defibrillators (ICDs), no consensus exists regarding their impact on quality of life (QoL). This systematic review investigates differences in QoL between patients with ICDs and controls. We systematically searched the MEDLINE, EMBASE, Cochrane, Web of Science, and PsychINFO databases. Articles were included if they were published after the year 2000 and reported on original studies with a control group. Five randomized controlled trials with a total of 5,138 patients and 10 observational studies with a total of 1,513 patients met the inclusion criteria. Nine studies found comparable QoL for ICD recipients and patients in the control groups, three studies found an increased QoL for ICD patients, and three studies found a decreased QoL for ICD patients. The question of whether QoL relates to ICD therapy cannot be answered conclusively due to the heterogeneity of the existing studies. Lower QoL was apparent among patients with an ICD who experienced several device discharges. Medical staff should be particularly aware of the signs of both psychological and physical disorders in these patients. Further investigations on QoL in ICD patients are desirable, but ethical reasons restrict the conduct of randomized trials. PMID:26664905

  11. 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

  12. Electrical storm in patients with an implanted defibrillator: a matter of definition.

    PubMed

    Israel, Carsten W; Barold, S Serge

    2007-10-01

    The term "electrical storm" (ES) indicates a state of cardiac electrical instability manifested by several episodes of ventricular tachyarrhythmias (VTs) within a short time. In patients with an implantable cardioverter defibrillator (ICD), ES is best defined as 3 appropriate VT detections in 24 h, treated by antitachycardia pacing, shock or eventually untreated but sustained in a VT monitoring zone. The number of shocks and inappropriate detections are irrelevant for the definition. ES occurs in approximately 25% of ICD patients within 3 years, with typically 5-55 individual VTs within one storm. Potential triggers can be found in approximately 66% of patients and include new/worsened heart failure, changes in antiarrhythmic medication, context with other illness, psychological stress, diarrhea, and hypokalemia. In most patients, ES consists of monomorphic VT indicating the presence of reentry while ventricular fibrillation indicating acute ischemia is rare. ES seems to have a low immediate mortality (1%) but frequently (50-80%) leads to hospitalization. Long-term prognostic implications of ES are unclear. The key intervention in ES is reduction of the elevated sympathetic tone by beta blockers and frequently benzodiazepines. Amiodarone i.v. has also been successful and azimilide seems promising while class I antiarrhythmic drugs are usually unsuccessful. Substrate mapping and VT ablation may be useful in treatment and prevention of ES. Prevention of ES requires ICD programming systematically avoiding unnecessary shocks (long VT detection, antitachycardia pacing where ever possible) which otherwise can fuel the sympathetic tone and prolong ES.

  13. Ironic Technology: Old Age and the implantable cardioverter defibrillator in US health care

    PubMed Central

    Kaufman, Sharon R.; Mueller, Paul S.; Ottenberg, Abigale L.; Koenig, Barbara A.

    2010-01-01

    We take the example of cardiac devices, specifically the implantable cardioverter defibrillator, or ICD, to explore the complex cultural role of technology in medicine today. We focus on persons age 80 and above, for whom ICD use is growing in the U.S. We highlight an ironic feature of this device. While it postpones death and ‘saves’ life by thwarting a lethal heart rhythm, it also prolongs living in a state of dying from heart failure. In that regard the ICD is simultaneously a technology of life extension and dying. We explore that irony among the oldest age group -- those whose considerations of medical interventions are framed by changing societal assumptions of what constitutes premature death, the appropriate time for death and medicine’s goals in an aging society. Background to the rapidly growing use of this device among the elderly is the ‘technological imperative’ in medicine, bolstered today by the value given to evidence-based studies. We show how evidence contributes to standards of care and to the expansion of Medicare reimbursement criteria. Together, those factors shape the ethical necessity of physicians offering and patients accepting the ICD in late life. Two ethnographic examples document the ways in which those factors are lived in treatment discussions and in expectations about death and longevity. PMID:21126815

  14. [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. PMID:24331838

  15. 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. PMID:24119393

  16. [Implantation of a dual chamber pacemaker-defibrillator (DDD-ICD) in a patient with hypertrophic obstructive cardiomyopathy].

    PubMed

    Neuberger, H R; Mewis, C; Dörnberger, V; Bosch, R F; Kühlkamp, V

    1999-07-01

    A 70-year-old woman with severely symptomatic hypertrophic obstructive cardiomyopathy was unresponsive to drug treatment. She had recurrent ventricular tachyarrhythmias and syncope and was at high risk for sudden death; a dual chamber pacemaker defibrillator (DDD-ICD) was implanted. Her initial left ventricular outflow tract gradient was 80 mm Hg and fell to 40 mm Hg during dual-chamber pacing at an atrial ventricular delay of 140 ms. In the follow-up over six months she was asymptomatic with respect to angina pectoris; ventricular tachycardias could be successfully terminated by antitachycardia pacing or by shocks. A dual chamber pacemaker defibrillator is an important therapeutic option for patients with symptomatic hypertrophic obstructive cardiomyopathy and ventricular tachyarrhythmias.

  17. 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.

  18. Influence of primary and secondary prevention indications on anxiety about the implantable cardioverter-defibrillator

    PubMed Central

    Rahmawati, Anita; Chishaki, Akiko; Ohkusa, Tomoko; Sawatari, Hiroyuki; Tsuchihashi-Makaya, Miyuki; Ohtsuka, Yuko; Nakai, Mori; Miyazono, Mami; Hashiguchi, Nobuko; Sakurada, Harumizu; Takemoto, Masao; Mukai, Yasushi; Inoue, Shujirou; Sunagawa, Kenji; Chishaki, Hiroaki

    2015-01-01

    Background Implantable cardioverter-defibrillators (ICDs) have been established for primary and secondary prevention of fatal arrhythmias. However, little is known about the influence of ICD indications on quality of life (QOL) and psychological disturbances. This study aimed to examine whether there were differences in QOL and psychological distress in patients that have an ICD for primary or secondary prevention of fatal arrhythmias. Methods A multicenter survey of 179 consecutive outpatients (29.1% primary prevention) with ICD implantations completed the Short Form-8 (SF-8), Beck Depression Inventory (BDI), Impact of Event Scale-Revised (IES-R), State-Trait Anxiety Inventory (STAI), and Worries about ICD (WAICD). Results Patients with an ICD for primary prevention had a higher trait anxiety score and worries about ICD score than patients with an ICD for secondary prevention (41.7±12.4 vs. 34.7±12.3, p=0.001 and 39.6±18.0 vs. 30.0±18.9, p=0.002, respectively), even after adjusting for demographic and clinical characteristics. In multivariable analysis of variance, primary prevention ICD recipients reported a poorer QOL on the vitality subscale of the SF-8. Conclusions In our study population, which mostly consisted of New York Heart Association (NYHA) class I and II subjects, primary prevention ICD recipients were more prone to experience worries about their ICD, anxiety, and a poorer QOL compared to secondary prevention ICD recipients. In clinical practice, primary prevention ICD patients should be closely monitored. If warranted, they should be offered psychological intervention, as anxiety and low QOL were predictors of mortality. PMID:27092190

  19. 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

  20. Prediction of ventricular arrhythmia events in ischemic heart disease patients with implantable cardioverter-defibrillators.

    PubMed

    Feng, Tianjie; Zhang, Shu; Chen, Keping; Hua, Wei; Ren, Xiaoqing

    2015-10-01

    The aim of the study was to exam the prediction of ventricular arrhythmia events in ischemic heart disease patients with implantable cardioverter-defibrillators (ICD). A total of 123 consecutive patients confirmed ischemia heart disease with ICD were examined. After device implantation, the occurrence of appropriate ICD therapy was noted. Patients were divided into two groups according to the ventricular arrhythmia occurrence. Patients with ventricular arrhythmia occurrence had a significantly great incidence of atrial fibrillation history compare to the no-ventricular arrhythmia occurrence group (8 vs. 39%, P = 0.02). The level of high-sensitive C-reactive protein (hsCRP) baseline was also significantly higher in the ventricular arrhythmia group than in the no ventricular arrhythmia (3.78 ± 1.1 vs. 0.94 ± 0.7, P < 0.01). The taking of β blocker is not common in ventricular arrhythmia group patients than no ventricular arrhythmia group (5 vs. 29%, P = 0.03). By univariate comparison, male sex, the history of atrial fibrillation, and a high level of hsCRP were significant predictors for ventricular arrhythmia occurrence. By multivariate analysis, the atrial fibrillation burden, and had a high level of hsCRP were significant for incidence of ventricular arrhythmia occurrence in ischemic heart disease patients. β-block were more likely to be free from ventricular arrhythmia occurrence. The high level of hsCRP, and the atrial fibrillation burden were strong predictor of ventricular arrhythmia occurrence in secondary prevention ICD recipients with ischemic heart disease. Taking β-blockers was free from ventricular arrhythmia occurrence.

  1. Rare infection of implantable cardioverter-defibrillator lead with Candida albicans: case report and literature review.

    PubMed

    Rivera, Nina Thakkar; Bray, Natasha; Wang, Hong; Zelnick, Kenneth; Osman, Ahmed; Vicuña, Ricardo

    2014-10-01

    Infection of implanted cardiac devices has a low rate of occurrence. Fungal infections of such devices represent an atypical phenomenon, associated with high mortality. Both medical and surgical therapies are recommended for a successful outcome. A 60-year-old woman with past medical history of heart failure with reduced ejection fraction, implantable cardioverter-defibrillator (ICD) placement, sarcoidosis and diabetes presented with fevers and atypical pleuritic chest pain. Transthoracic echocardiogram revealed a highly mobile 2.09 cm by 4.49 cm mass associated with the ICD wire. Blood cultures were positive for Candida albicans. The patient underwent sternotomy for removal. The vegetation was 4 cm by 2 cm by 2 cm in size, attached to the right ventricle without interference with the tricuspid valve. The patient was treated with micafungin for 2 weeks and then fluconazole for 6 weeks. In this case report, we describe the rare infection of an ICD lead with C. albicans, in the form of a fungal ball. This is the 18th reported case of Candida device-related endocarditis and the first reported in a woman. Prior case reports have occurred primarily in pacemaker rather than ICD leads. The vegetation size is also one of the largest that has been reported, measuring 4 cm at its greatest length. As Candida device-related endocarditis is so rare, and as fatality occurs in half of cases, clinical management can only be derived from sporadic case reports. Therefore, the course of this patient's disease care will be a useful adjunct to the current literature for determining treatment and prognosis in similar cases.

  2. Referring Physicians’ Discordance with the Primary Prevention Implantable Cardioverter-Defibrillator Guidelines: A National Survey

    PubMed Central

    Castellanos, Jorge M; Smith, Lisa M; Varosy, Paul D.; Dehlendorf, Christine; Marcus, Gregory M

    2012-01-01

    BACKGROUND The ACC/AHA/HRS Guidelines provide patient selection criteria for primary prevention implantable cardioverter-defibrillators (ICDs). For unknown reasons, guideline discordant practice is common. OBJECTIVE To determine referring physicians’ concordance with the primary prevention ICD guidelines. METHODS We mailed a survey regarding ICD guidelines and individual practice characteristics to a random national sample of 3,000 physicians, 1/3rd each specializing in family medicine, internal medicine, and general cardiology, selected from the American Medical Association Masterfile. RESULTS Sixty-four percent with correct contact information responded. Three hundred and ninety-five (28%, 95% CI 25–30%) respondents never refer patients with the intent of consideration for a primary prevention ICD, including 7% (95% CI 5–10%) of cardiologists. Two hundred and twelve (15%, 95% CI 13–17%) believe ventricular arrhythmias are required before a primary prevention ICD is indicated; 525 (36%, 95% CI 34–39%) believe an ejection fraction > 40% warrants a primary prevention ICD; and 361 (25%, 95% CI 23–27%) would refer a patient for a primary prevention ICD within 40 days of a myocardial infarction. In multivariate analyses, family practice physicians and physicians residing in the Western US most often provided guideline-discordant answers, while cardiologists and those that refer to an electrophysiologist most often provided guideline-concordant answers. Primary care physicians that manage heart failure patients without referral to a subspecialist were not more likely to provide guideline concordant answers. CONCLUSIONS Answers discordant with the primary prevention ICD guidelines were common, suggesting that referring physician beliefs are an important barrier to appropriate patient referrals for primary prevention ICD implantation. PMID:22306794

  3. New insights into defibrillation of the heart from realistic simulation studies.

    PubMed

    Trayanova, Natalia A; Rantner, Lukas J

    2014-05-01

    Cardiac defibrillation, as accomplished nowadays by automatic, implantable devices, constitutes the most important means of combating sudden cardiac death. Advancing our understanding towards a full appreciation of the mechanisms by which a shock interacts with the heart, particularly under diseased conditions, is a promising approach to achieve an optimal therapy. The aim of this article is to assess the current state-of-the-art in whole-heart defibrillation modelling, focusing on major insights that have been obtained using defibrillation models, primarily those of realistic heart geometry and disease remodelling. The article showcases the contributions that modelling and simulation have made to our understanding of the defibrillation process. The review thus provides an example of biophysically based computational modelling of the heart (i.e. cardiac defibrillation) that has advanced the understanding of cardiac electrophysiological interaction at the organ level, and has the potential to contribute to the betterment of the clinical practice of defibrillation.

  4. Prevalence and outcomes of patients receiving implantable cardioverter-defibrillators for primary prevention not based on guidelines.

    PubMed

    Levine, Yehoshua C; Tuttle, Mark K; Rosenberg, Michael A; Goldberg, Randal; Matos, Jason; Samuel, Michelle; Kramer, Daniel B; Buxton, Alfred E

    2015-06-01

    Implantable cardioverter-defibrillator (ICD) implantation outside practice guidelines remains contentious, particularly during the mandated waiting periods in patients with recent cardiac events. We assessed the prevalence and outcomes of non-guideline-based (NGB) ICD implantations in a tertiary academic medical center, with a specific focus on adjudication of arrhythmia events. All patients who underwent initial primary prevention ICD implantation at our institution from 2004 to 2012 were categorized as having received guideline-based (GB) or NGB implants and were retrospectively assessed for first episode of appropriate ICD therapy and total mortality. Of 807 patients, 137 (17.0%) received NGB implants. During a median follow-up of 2.9 years, patients with NGB implants had similar times to first appropriate ICD therapy (median time to event 1.94 vs 2.17 years in patients with GB implants, p = 0.20). After multivariable analysis, patients with NGB implants remained at higher risk for death (hazard ratio 1.54, 95% confidence interval 1.1 to 2.2, p = 0.03) but not appropriate ICD therapy (hazard ratio 0.83, 95% confidence interval 0.5 to 1.3, p = 0.51). Furthermore, only 1 of 125 patients who underwent implant within the 40-day waiting period after myocardial infarction or 3-month waiting period after revascularization or cardiomyopathy diagnosis received an appropriate therapy within this period. In conclusion, few patients received NGB ICD implants in our academic medical center. Although these patients have similar long-term risk of receiving appropriate ICD therapy compared with patients with GB implants, this risk is very low during the waiting periods mandated by clinical practice guidelines. These results suggest that there is little need to rush into implanting ICDs during these waiting periods. PMID:25840578

  5. Automated external defibrillators (AEDs).

    PubMed

    2003-06-01

    Automated external defibrillators, or AEDs, will automatically analyze a patient's ECG and, if needed, deliver a defibrillating shock to the heart. We sometimes refer to these devices as AED-only devices or stand-alone AEDs. The basic function of AEDs is similar to that of defibrillator/monitors, but AEDs lack their advanced capabilities and generally don't allow manual defibrillation. A device that functions strictly as an AED is intended to be used by basic users only. Such devices are often referred to as public access defibrillators. In this Evaluation, we present our findings for a newly evaluated model, the Zoll AED Plus. We also summarize our findings for the previously evaluated model that is still on the market and describe other AEDs that are also available but that we haven't evaluated. We rate the models collectively for first-responder use and public access defibrillation (PAD) applications.

  6. 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

  7. 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

  8. Readability and Content of Patient Education Material Related to Implantable Cardioverter Defibrillators

    PubMed Central

    Strachan, Patricia H.; de Laat, Sonya; Carroll, Sandra L.; Schwartz, Lisa; Vaandering, Katie; Toor, Gurjit K.; Arthur, Heather M.

    2012-01-01

    Background Implantable cardioverter defibrillators (ICDs) are increasingly offered to patients for primary prevention of sudden cardiac death. Candidates for ICD receive ICD-related patient education material when they make decisions to consent or decline a primary prevention ICD. Printed patient education material directed at ICD candidates has not been the focus of direct appraisal. Objective We evaluated the readability and content of ICD-related print education materials made available to patients who were enrolled in a study involving patient decision making for ICD from 3 ICD sites in southern Ontario, Canada. Methods All ICD print materials referred to during interviews and/or that were available in ICD site waiting rooms were collected for analysis. Readability testing was conducted using the SMOG (“simple measurement of gobbledygook”) and Fry methods. The material was evaluated according to selected plain-language criteria, thematic content analysis, and rhetoric analysis. Results Twenty-one print materials were identified and analyzed. Documents were authored by device manufacturers, tertiary care hospitals, and cardiac support organizations. Although many documents adhered to plain-language recommendations, text-reading levels were higher than recommended. Twelve major content themes were identified. Content focused heavily on the positive aspects of living with the device to the exclusion of other possible information that could be relevant to the decisions that patients made. Conclusions Print-based patient education materials for ICD candidates are geared to a highly literate population. The focus on positive information to the exclusion of potentially negative aspects of the ICD, or alternatives to accepting 1, could influence and/or confuse patients about the purpose and implications of this medical device. Development of print materials is indicated that includes information about possible problems and that would be relevant for the

  9. 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.

  10. Cognitive behavioral therapy (CBT) in a Patient with Implantable Cardioverter Defibrillator (ICD) and Posttraumatic stress disorder(PTSD).

    PubMed

    Ansari, Sahar; Arbabi, Mohammad

    2014-07-01

    The implantable cardioverter defibrillator (ICD) has currently become the standard treatment for preventing sudden cardiac death. There are some psychological consequences in patients with ICD such as posttraumatic stress disorder (PTSD) after the shocks induced by ICD. This report aimed to present the case of a 54-year-old man with ICD who had developed PTSD; his PTSD was treated, using cognitive-behavioral psychotherapy consisting of relaxation, mindfulness and problem solving techniques. In patients with ICD who are experiencing PTSD using cognitive behavioral interventions may be helpful to reduce their psychological sufferings.

  11. 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

  12. 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

  13. Implantable cardioverter defibrillator therapy in pediatric and congenital heart disease patients: a single tertiary center experience in Korea

    PubMed Central

    Jin, Bo Kyung; Bang, Ji Seok; Choi, Eun Young; Kim, Gi Beom; Kwon, Bo Sang; Noh, Chung Il; Choi, Jung Yun; Kim, Woong Han

    2013-01-01

    Purpose The use of implantable cardioverter defibrillators (ICDs) to prevent sudden cardiac death is increasing in children and adolescents. This study investigated the use of ICDs in children with congenital heart disease. Methods This retrospective study was conducted on the clinical characteristics and effectiveness of ICD implantation at the department of pediatrics of a single tertiary center between 2007 and 2011. Results Fifteen patients underwent ICD implantation. Their mean age at the time of implantation was 14.5±5.4 years (range, 2 to 22 years). The follow-up duration was 28.9±20.4 months. The cause of ICD implantation was cardiac arrest in 7, sustained ventricular tachycardia in 6, and syncope in 2 patients. The underlying disorders were as follows: ionic channelopathy in 6 patients (long QT type 3 in 4, catecholaminergic polymorphic ventricular tachycardia [CPVT] in 1, and J wave syndrome in 1), cardiomyopathy in 5 patients, and postoperative congenital heart disease in 4 patients. ICD coils were implanted in the pericardial space in 2 children (ages 2 and 6 years). Five patients received appropriate ICD shock therapy, and 2 patients received inappropriate shocks due to supraventricular tachycardia. During follow-up, 2 patients required lead dysfunction-related revision. One patient with CPVT suffered from an ICD storm that was resolved using sympathetic denervation surgery. Conclusion The overall ICD outcome was acceptable in most pediatric patients. Early diagnosis and timely ICD implantation are recommended for preventing sudden death in high-risk children and patients with congenital heart disease. PMID:23559974

  14. Impact of dual chamber pacing on the incidence of atrial and ventricular tachyarrhythmias in recipients of implantable cardioverter defibrillators.

    PubMed

    Strohmer, Bernhard; Mermi, Johann; Castellanos, Eduardo; Mayr, Harald; Gill, Jaswinder; Abadia, Antonio Asso; Kuehl, Martin; Wolpert, Christian

    2005-01-01

    Recent observations suggest that frequent dual-chamber pacing in recipients of implantable cardioverter defibrillators (ICD) may adversely influence clinical outcomes. This prospective, multicenter study examined the relationship between the frequency of atrial (%AP) and ventricular pacing (%VP) and the incidence of atrial (AT) and/or ventricular tachyarrhythmias (VT) in a standard ICD population. A total of 141 consecutive patients with primary and secondary ICD indications were studied. Continuous arrhythmia detection with a dual-chamber ICD revealed paroxysmal AT in 60 (43%) and VT in 72 (51%) patients within 6 months of device implantation. Far-field oversensing of ventricular signals occurred in 13% of all "atrial tachy response" mode switches. Without adjustment for covariates, a higher %AP was associated with an increased incidence of AT (P < 0.05). However, this association remained only weakly significant after adjustment for covariates using a multivariate model. High New York heart failure functional classes correlated significantly with AT (P = 0.02) and VT (P = 0.007). Rate-modulated pacing, programmed in 1/3 of patients, correlated with occurrence of AT (P = 0.006), but not with occurrence of VT. With respect to dual-chamber pacing, a %AP >/= 48% combined with a %VP > 40% was associated with an increased probability for VT. In conclusion, AT and VT occurred frequently within 6 months after dual-chamber ICD implantation. High rates of DDD/R stimulation were associated with a trend toward higher incidence of AT, VT, or both.

  15. 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

  16. T-wave oversensing by an implantable cardioverter defibrillator after successful ablation of idiopathic ventricular fibrillation.

    PubMed

    Strohmer, Bernhard; Schernthaner, Christiana; Pichler, Maximilian

    2006-04-01

    Focal ablation of trigger premature ventricular complexes (PVCs) from the Purkinje system helped to suppress idiopathic ventricular fibrillation (VF) in an athlete who had suffered from frequent appropriate shock therapies. However, only a few days after successful ablation T-wave oversensing occurred during exercise and resulted in repetitive distressing defibrillator shocks. Despite lack of any changes on the surface ECG, the endocardially recorded electrogram revealed an unfavorable ratio of R-to-T-wave amplitude predisposing to double counting with accelerated heart rates. This case illustrates that T-wave oversensing may complicate the clinical course after successful ablation of malignant Purkinje ectopy.

  17. Automatic adjustment of chopping-modulated defibrillation pulses to patient transthoracic resistance.

    PubMed

    Krasteva, V; Cansell, A; Daskalov, I

    2003-01-01

    Defibrillation of the heart requires a high amplitude short duration current pulse to be passed through large electrodes placed on the patient's chest. The current meets a virtually active resistance, which can vary in the approximate range of 25 to 180 Omega. As the delivered current or energy depends on the resistance, several methods have been developed to reduce or compensate its influence. For example, pre-shock resistance has been measured by a high-frequency current and the current or energy set accordingly; measurements have been made from the initial tilt and the pulse durations adjusted; and pre-shock measurements have been made by a sub-shock pulse to generate an appropriately selected constant current. A method is proposed using high-frequency chopped biphasic pulses, with pulse-width and period modulation of the elementary pulses. Patient resistance is measured with the first elementary pulse and depending on its value a modulated waveform is generated, selected by a micro-controller from a preprogrammed set. Thus the selected energy is accurately delivered to the patient. In addition, this method allows the shaping of a desired mean patient current waveform, maintaining adequate charge balance between the two phases and securing an appropriate time course of the model-derived transmembrane potential. PMID:12623607

  18. Do implantable cardioverter defibrillators improve survival in patients with severe left ventricular systolic dysfunction after coronary artery bypass graft surgery?

    PubMed

    Fazal, Iftikhar A; Bates, Matthew G D; Matthews, Iain G; Turley, Andrew J

    2011-06-01

    A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether implantable cardioverter defibrillators (ICD) improve survival in patients with severe left ventricular systolic dysfunction (LVSD) after coronary artery bypass graft (CABG) surgery. ICDs are designed to terminate potentially fatal cardiac tachyarrhythmias. A right ventricular lead is mandatory for detection, pacing and defibrillation capabilities. Dual chamber ICDs have an additional right atrial lead and are used for patients with conventional atrioventricular pacing indications. More sophisticated, biventricular devices exist to provide cardiac resynchronisation therapy (CRT) in addition to defibrillation (CRT-D). ICDs have been extensively investigated in patients with LVSD post myocardial infarction and in patients with non-ischaemic cardiomyopathy for both secondary prevention (history of ventricular arrhythmias) and primary prevention (deemed high risk for ventricular arrhythmias). This best evidence topic aims to review the evidence and its applicability to patients post CABG. Nine hundred and sixteen papers were identified using the search method outlined. Eight randomised controlled trials, two meta-analyses, and one non-randomised trial, in addition to international guidelines presented the best evidence to answer the clinical question. The current evidence base and guidelines suggest that ICDs should be considered for all patients with LVSD [ejection fraction (EF) ≤30-40%] receiving optimal pharmacological management, who are ≥40 days post MI [four weeks for National Institute for Health and Clinical Excellence (NICE)] and in New York Heart Association (NYHA) class I-III. UK NICE guidelines require in addition; non-sustained ventricular tachycardia (NSVT) on a Holter monitor and inducible ventricular tachycardia at electrophysiological study for EF between 30 and 35%; or a QRS >120 ms if EF <30%. The North American guidelines

  19. Implantable Cardioverter-Defibrillator Shock after Stenting Across the Device Leads.

    PubMed

    Mehra, Sanjay; Chelu, Mihail Gabriel

    2016-02-01

    A 45-year-old man with nonischemic cardiomyopathy and end-stage renal disease had lived uneventfully with a cardiac resynchronization therapy defibrillator (CRT-D) for 5 years. Less than a month before presenting at our institution, he had undergone stenting of his partially occluded subclavian vein, to relieve stenosis of the ipsilateral arteriovenous fistula that was used for his hemodialysis. The CRT-D subsequently discharged. Device interrogation revealed that electrical noise originating from leads damaged by the stent had caused the inappropriate shock and intermittent electrical discharges thereafter. The patient was highly traumatized by these events and insisted upon device removal, which deprived him of a potentially life-saving intervention. He later had a cardiac arrest that resulted in sustained profound hypoxic ischemic encephalopathy with minimal neurologic recovery: his family placed him in a long-term care facility on ventilator support, with a tracheostomy and feeding tube. This situation might have been avoided through collaboration between the interventional radiologist and the electrophysiologist. To our knowledge, this is the first report of a patient with nonischemic cardiomyopathy and end-stage renal disease who presented with inappropriate defibrillator discharge caused by lead damage secondary to stenting across the leads. PMID:27047295

  20. Implantable Cardioverter-Defibrillator Shock after Stenting Across the Device Leads

    PubMed Central

    Chelu, Mihail Gabriel

    2016-01-01

    A 45-year-old man with nonischemic cardiomyopathy and end-stage renal disease had lived uneventfully with a cardiac resynchronization therapy defibrillator (CRT-D) for 5 years. Less than a month before presenting at our institution, he had undergone stenting of his partially occluded subclavian vein, to relieve stenosis of the ipsilateral arteriovenous fistula that was used for his hemodialysis. The CRT-D subsequently discharged. Device interrogation revealed that electrical noise originating from leads damaged by the stent had caused the inappropriate shock and intermittent electrical discharges thereafter. The patient was highly traumatized by these events and insisted upon device removal, which deprived him of a potentially life-saving intervention. He later had a cardiac arrest that resulted in sustained profound hypoxic ischemic encephalopathy with minimal neurologic recovery: his family placed him in a long-term care facility on ventilator support, with a tracheostomy and feeding tube. This situation might have been avoided through collaboration between the interventional radiologist and the electrophysiologist. To our knowledge, this is the first report of a patient with nonischemic cardiomyopathy and end-stage renal disease who presented with inappropriate defibrillator discharge caused by lead damage secondary to stenting across the leads. PMID:27047295

  1. Implantable Defibrillators for Secondary Prevention of Sudden Cardiac Death in Cardiac Surgery Patients With Perioperative Ventricular Arrhythmias

    PubMed Central

    Nageh, Maged F.; Kim, John J.; Chen, Lie‐Hong; Yao, Janis F.

    2014-01-01

    Background Randomized studies of implantable cardioverter defibrillators (ICD) have excluded sudden cardiac death survivors who had revascularization before or after an arrhythmic event. To evaluate the role of ICD and the effects of clinical variables including degree of revascularization, we studied cardiac surgery patients who had an ICD implanted for sustained perioperative ventricular arrhythmias. Methods and Results The electronic database for Southern California Kaiser Foundation hospitals was searched for patients who had cardiac surgery between 1999 and 2005 and an ICD implanted within 3 months of surgery. One hundred sixty‐four patients were identified; 93/164 had an ICD for sustained pre‐ or postoperative ventricular tachycardia or fibrillation requiring resuscitation. Records were reviewed for the following: presenting arrhythmia, ejection fraction, and degree of revascularization. The primary end point was total mortality (TM) and/or appropriate ICD therapy (ICD‐T), and secondary end points are TM and ICD‐T. During the mean follow up of 49 months, the primary endpoint of TM+ICD‐T and individual end points of TM and ICD‐T were observed in 52 (56%), 35 (38%), and 28 (30%) patients, respectively, with 55% of TM, and 23% of ICD‐T occurring within 2 years of implant. In multivariate risk analysis, none of the following was associated with any of the end points: incomplete revascularization, presenting ventricular arrhythmia, and timing of arrhythmias. Conclusion Our data supports the recent guidelines for ICD in this cohort of patients, as the presence of irreversible substrate and triggers of ventricular arrhythmias, cannot be reliably excluded even with complete revascularization. Further studies are needed to understand this complex group of patients. PMID:25146702

  2. 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

  3. Treatment of out-of-hospital cardiac arrest with a low-energy impedance-compensating biphasic waveform automatic external defibrillator. The LIFE Investigators.

    PubMed

    Gliner, B E; Jorgenson, D B; Poole, J E; White, R D; Kanz, K G; Lyster, T D; Leyde, K W; Powers, D J; Morgan, C B; Kronmal, R A; Bardy, G H

    1998-01-01

    Few victims of sudden cardiac arrest survive. A new generation of automatic external defibrillators (AEDs), smaller, lighter, easier to use, and less costly, makes the goal of widespread AED deployment and early defibrillation feasible. A low-energy impedance-compensating biphasic waveform allows AED device characteristics more suitable to the goal of early defibrillation than high-energy waveforms. This study observed the performance of such a biphasic waveform in the out-of-hospital setting on 100 consecutive victims of sudden cardiac arrest treated by a wide range of first-responders. AEDs incorporating 150-J impedance-compensating biphasic waveforms were placed into service of 34 EMS systems. Data were obtained from the AED PC data card-recording system. The first endpoint was to determine the effectiveness of this waveform in terminating ventricular fibrillation (VF). The second endpoint was to determine whether or not the use of such an AED culminated in an organized rhythm at the time of patient transfer to an advanced life support (ALS) team or emergency department (ED). The third endpoint was to assess the efficiency of the human-factors design of the AED by measuring user time intervals. The 34 sites provided data from 286 consecutive AED uses, 100 from SCA victims with VF as their initial rhythm upon attachment of the AED. All 286 patients were correctly identified by the AED as requiring a shock (100% sensitivity for the 100 VF patients) or not (100% specificity to the 186 patients not presenting in VF). Times from emergency call to first shock delivery averaged 9.1 +/- 7.3 minutes. A single 150-J biphasic shock defibrillated the initial VF episode in 86% of patients. For all 450 episodes of VF in these 100 patients, an average of 86% +/- 24% of VF episodes were terminated with a single biphasic shock. Of the 449 VF episodes that received up to three shocks, 97% +/- 11% were terminated with three shocks or fewer. The average number of shocks per VF

  4. 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

  5. Replacement of implantable cardioverter defibrillators and cardiac resynchronization therapy devices: results of the European Heart Rhythm Association survey.

    PubMed

    Tilz, Roland; Boveda, Serge; Deharo, Jean-Claude; Dobreanu, Dan; Haugaa, Kristina H; Dagres, Nikolaos

    2016-06-01

    The aim of this EP Wire was to assess the management, indications, and techniques for implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy (CRT) device replacement in Europe. A total of 24 centres in 14 European countries completed the questionnaire. All centres were members of the European Heart Rhythm Association Electrophysiology Research Network. Replacement procedures were performed by electrophysiologists in 52% of the centres, by cardiologists in 33%, and both in the remaining centres. In the majority of centres, the procedures were performed during a short hospitalization (<2 days; 61.2%), or on an outpatient basis (28%). The overwhelming majority of centres reported that they replaced ICDs at the end of battery life. Only in a small subset (<10%) of patients with ICD for primary prevention and without ventricular tachycardia (VT) since implantation, ICD was not replaced. In inherited primary arrhythmia syndromes, 80% of the centres always replaced the ICD at the end of battery life. After VT ablation, only few centres (9%) explanted or downgraded the device that was previously implanted for secondary prevention, but only in those patients without new VT episodes. Patient's life expectancy <1 year was the most commonly reported reason (61%) to downgrade from a CRT-D to a CRT-P device. While warfarin therapy was continued in 47% of the centres, non-vitamin K oral anticoagulants were discontinued without bridging 24 h prior to replacement procedures in 60%. Finally, in 65% of the centres, VT induction and shock testing during ICD and CRT-D replacement were performed only in the case of leads with a warning or with borderline measurements. This survey provides a snapshot of the perioperative management, indications, and techniques of ICD and CRT device replacement in Europe. It demonstrates some variations between participating centres, probably related to local policies and to the heterogeneity of the ICD population. PMID

  6. Potential clinical impact of cardiovascular magnetic resonance assessment of ejection fraction on eligibility for cardioverter defibrillator implantation

    PubMed Central

    2012-01-01

    Background For the primary prevention of sudden cardiac death, guidelines provide left ventricular ejection fraction (EF) criteria for implantable cardioverter defibrillator (ICD) placement without specifying the technique by which it should be measured. We sought to investigate the potential impact of performing cardiovascular magnetic resonance (CMR) for EF on ICD eligibility. Methods The study population consisted of patients being considered for ICD implantation who were referred for EF assessment by CMR. Patients who underwent CMR within 30 days of echocardiography were included. Echocardiographic EF was determined by Simpson’s biplane method and CMR EF was measured by Simpson’s summation of discs method. Results Fifty-two patients (age 62±15 years, 81% male) had a mean EF of 38 ± 14% by echocardiography and 35 ± 14% by CMR. CMR had greater reproducibility than echocardiography for both intra-observer (ICC, 0.98 vs 0.94) and inter-observer comparisons (ICC 0.99 vs 0.93). The limits of agreement comparing CMR and echocardiographic EF were – 16 to +10 percentage points. CMR resulted in 11 of 52 (21%) and 5 of 52 (10%) of patients being reclassified regarding ICD eligibility at the EF thresholds of 35 and 30% respectively. Among patients with an echocardiographic EF of between 25 and 40%, 9 of 22 (41%) were reclassified by CMR at either the 35 or 30% threshold. Echocardiography identified only 1 of the 6 patients with left ventricular thrombus noted incidentally on CMR. Conclusions CMR resulted in 21% of patients being reclassified regarding ICD eligibility when strict EF criteria were used. In addition, CMR detected unexpected left ventricular thrombus in almost 10% of patients. Our findings suggest that the use of CMR for EF assessment may have a substantial impact on management in patients being considered for ICD implantation. PMID:23043729

  7. 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. PMID

  8. Worldwide experience with a totally subcutaneous implantable defibrillator: early results from the EFFORTLESS S-ICD Registry

    PubMed Central

    Lambiase, Pier D.; Barr, Craig; Theuns, Dominic A.M.J.; Knops, Reinoud; Neuzil, Petr; Johansen, Jens Brock; Hood, Margaret; Pedersen, Susanne; Kääb, Stefan; Murgatroyd, Francis; Reeve, Helen L.; Carter, Nathan; Boersma, Lucas; Adragão, P.; Agarwal, S.; Barr, C.; Boersma, L.; Brock-Johanssen, J.; Butter, C.; Calò, L.; Eckhardt, L.; Gulizia, M.; Scholten, M.; Dekker, L.; Khiani, R.; Hjortshot, S.; Høgh Petersen, H.; Hood, M.; Kääb, S.; Knops, R.; Kuschyk, J.; Lambiase, P.; Maass, K. A.; McLeod, K.; Molon, G.; Morgan, J.; Mortensen, P.; Murgatroyd, F.; Neuzil, P.; Pepper, C.; Sheridan, P.; Stellbrink, C.; Stuart, G.; Theuns, D.; Vernooy, K.; Veltmann, C.; Wende, C.

    2014-01-01

    Aims The totally subcutaneous implantable-defibrillator (S-ICD) is a new alternative to the conventional transvenous ICD system to minimize intravascular lead complications. There are limited data describing the long-term performance of the S-ICD. This paper presents the first large international patient population collected as part of the EFFORTLESS S-ICD Registry. Methods and results The EFFORTLESS S-ICD Registry is a non-randomized, standard of care, multicentre Registry designed to collect long-term, system-related, clinical, and patient reported outcome data from S-ICD implanted patients since June 2009. Follow-up data are systematically collected over 60-month post-implant including Quality of Life. The study population of 472 patients of which 241 (51%) were enrolled prospectively has a mean follow-up duration of 558 days (range 13–1342 days, median 498 days), 72% male, mean age of 49 ± 18 years (range 9–88 years), 42% mean left ventricular ejection fraction. Complication-free rates were 97 and 94%, at 30 and 360 days, respectively. Three hundred and seventeen spontaneous episodes were recorded in 85 patients during the follow-up period. Of these episodes, 169 (53%) received therapy, 93 being for Ventricular Tachycardia/Fibrillation (VT/VF). One patient died of recurrent VF and severe bradycardia. Regarding discrete VT/VF episodes, first shock conversion efficacy was 88% with 100% overall successful clinical conversion after a maximum of five shocks. The 360-day inappropriate shock rate was 7% with the vast majority occurring for oversensing (62/73 episodes), primarily of cardiac signals (94% of oversensed episodes). Conclusion The first large cohort of real-world data from an International patient S-ICD population demonstrates appropriate system performance with clinical event rates and inappropriate shock rates comparable with those reported for conventional ICDs. Clinical trial registration URL: http://www.clinicaltrials.gov. Unique identifier NCT

  9. 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)

  10. 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.

  11. 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.

  12. [Who dictates the rhythm which must be followed? : Pacemakers and implantable cardioverter defibrillators in anesthesiology].

    PubMed

    Bischoff, M; Walther, A; Serf, C

    2011-08-01

    The number of patients with implantable cardiac devices for the treatment of cardiac dysrhythmia is steadily climbing. Due to the increase in indications for implantation and the range of functions, an end to this development is not yet in sight. In order to provide safety in the everyday handling of these systems it is necessary to pay attention to various aspects prior to, during and after surgery or anesthesia.

  13. Anger-induced T-wave alternans predicts future ventricular arrhythmias in patients with implantable cardioverter-defibrillators

    PubMed Central

    Lampert, Rachel; Shusterman, Vladimir; Burg, Matthew; McPherson, Craig; Batsford, William; Goldberg, Anna; Soufer, Robert

    2014-01-01

    Objective To determine whether T-wave alternans (TWA) induced by anger in a laboratory setting predicts future ventricular arrhythmias (VT/VF) in patients with implantable cardioverter-defibrillators (ICDs). Background Anger can precipitate spontaneous VT/VF, and induce TWA. Whether anger-induced TWA predicts future arrhythmias is unknown. Methods Sixty-two patients with ICDs underwent ambulatory ECG during a mental stress protocol, three months post-implant. TWA was analyzed using time-domain methods. After ≥ 1 year follow-up, ICD stored data was reviewed to determine incidence of ICD-terminated VT/VF. Results Patients with ICD-terminated arrhythmias during follow-up (N=10) had higher TWA induced by anger, 13.2uV (iqr 9.3-16), compared to 9.3uV (7.5-11.5) (p<0.01). Patients in the highest quartile of anger-induced TWA (>11.9uV, N=15) were more likely to experience arrhythmias by one year than those in the lower quartiles, (33% versus 4%), and during extended follow-up (40% versus 9%, p<0.01 for both.) In multivariable regression controlling for ejection fraction, prior clinical arrhythmia, and wide QRS, anger-induced TWA remained a significant predictor of arrhythmia, with likelihood in the top quartile 10.8 times that of other patients (CI 1.6-113, p<0.05.) Conclusion Anger-induced TWA predicts future ventricular arrhythmias in patients with ICDs, suggesting that emotion-induced repolarization instability may be one mechanism linking stress and sudden death. Whether there is a clinical role for anger-induced TWA testing requires further study. PMID:19245968

  14. Cognitive-Behavioral Treatment of Posttraumatic Stress in Patients With Implantable Cardioverter Defibrillators: Results From a Randomized Controlled Trial.

    PubMed

    Ford, Jessica; Rosman, Lindsey; Wuensch, Karl; Irvine, Jane; Sears, Samuel F

    2016-08-01

    Approximately 20% of patients with implantable cardioverter defibrillators (ICDs) suffer from posttraumatic stress disorder (PTSD) due to a history of cardiac arrest, device implantation, and ICD shock. There has been very little examination of treatment of PTSD symptoms in these patients. This study evaluated the effect of a specific cognitive-behavioral therapy (CBT) intervention for ICD patients with high levels of PTSD symptoms: a manualized program consisting of 8 telephone sessions with a trained counselor, a patient education book, and a stress management procedure on compact disc. Participants were 193 ICD patients, who were randomized to CBT or usual cardiac care (UCC) who completed self-report surveys at the time of recruitment and 6 and 12 months after initial measurement. Previous publication on the primary research evaluation questions reported that the CBT condition resulted in greater improvement on PTSD and depression symptoms than the UCC for the general population of ICD patients, but did not evaluate the effect on those with elevated symptoms of PTSD. The authors conducted secondary analyses of the effect of treatment on high and low PTSD symptom groups based on a cutoff for the Impact of Event Scale-Revised (Weiss & Marmar, 1997). Participants in the CBT group who had high symptoms experienced significantly greater symptom reduction from baseline to 12 months (d = 2.44, p = .021) than the UCC group (d = 1.12). Participants with low symptoms had small reductions regardless of group assignment (d = 0.16, p = .031). ICD-focused CBT was sufficient to produce a large, statistically significant reduction in PTSD symptoms in ICD patients with indications for treatment.

  15. Rationale and design of a prospective study of the efficacy of a remote monitoring system used in implantable cardioverter defibrillator follow-up: the Lumos-T Reduces Routine Office Device Follow-Up Study (TRUST) study.

    PubMed

    Varma, Niraj

    2007-12-01

    Increased implantable cardioverter defibrillator (ICD) implant volumes (and product advisories/recalls) pose management challenges. Most device interrogations at 3- to 6-month routine follow-up visits are "nonactionable," that is, require no clinically significant reprogramming, lead revision, or initiation or up-titration of antiarrhythmic medications. Conversely, implanted devices collect important diagnostic data (eg, atrial fibrillation onset, system integrity) that remain concealed between device interrogations. Remote monitoring may resolve some of these challenges, but has not been studied in a large-scale clinical trial. Home Monitoring (HM) uses automatic (without patient intervention) data and electrogram transmissions with rapid (<24 hours) event notification of significant (including silent) events. The Lumos-T Reduces Routine Office Device Follow-Up Study (TRUST) is a multicenter, prospective, randomized study enrolling 1000 ICD patients designed to test whether HM can safely reduce the number of scheduled nonactionable office device interrogations by 50% and provide early detection and notification of cardiac and/or device problems. After enrollment, TRUST patients are randomized 2:1 to either HM or to control (ie, HM off) arms and are seen for an in-office follow-up 3 months postimplant. At subsequent 3-month intervals, control patients have conventional office visits, whereas in HM, patient data are remotely retrieved and evaluated. In HM patients, early notification may automatically occur between periodic checks for compromised system integrity (battery, lead parameters, high-voltage circuitry) or arrhythmia occurrence (eg, atrial fibrillation, ventricular arrhythmia). All study patients will have a final office visit 15 months after implant. The results of TRUST may confirm the role of remote monitoring as an intensive surveillance mechanism for device management. PMID:18035071

  16. Effect of Advancing Age and Multiple Chronic Conditions on Mortality in Patients with End-Stage Renal Disease after Implantable Cardioverter-Defibrillator Placement

    PubMed Central

    Krishnaswami, Ashok; Kiley, Mary-Lou; Anthony, Faith F; Chen, Yuexin; Chen, Jason; Rajagopal, Sumanth; Liu, Taylor I; Young, Charlie; Paxton, Elizabeth W

    2016-01-01

    Context: There is insufficient information on the effect that advancing age and multiple chronic conditions (MCC) have on mortality after placement of an implantable cardioverter-defibrillator in patients with end-stage renal disease (ESRD) vs non-ESRD. Objective: To assess whether a differential effect of age and MCC exists between ESRD and non-ESRD. Design: Population-based, retrospective cohort study using data from the national Kaiser Permanente Cardiac Device Registry of patients who underwent placement of an implantable cardioverter-defibrillator between January 1, 2007, and December 31, 2013. Main Outcome Measures: All-cause mortality. Results: Of 7825 patients with implantable cardioverter-defibrillator placement, ESRD-affected patients constituted 4.0% of the cohort (n = 311), were similar in age (p = 0.91), and presented with a larger comorbidity burden (3.3 ± 1.3 vs 2.4 ± 1.5, p < 0.001). The effect of advancing age (every 5 years) on mortality in the ESRD cohort (hazard ratio [HR] = 1.11, 95% confidence interval [CI] = 1.03–1.20) was less than in the non-ESRD cohort (HR = 1.28, 95% CI = 1.25–1.32). Similarly, the effect of each additional comorbidity in the ESRD cohort was less (HR = 1.04, 95% CI = 0.91–1.19) than in the non-ESRD group (HR = 1.20, 95% CI = 1.16–1.25). Lastly, ESRD was independently associated with a 3-fold greater hazard of mortality. Conclusions: Advancing age and increasing number of MCC have a differential effect on mortality risk in patients with ESRD compared with their non-ESRD counterparts. Future studies should focus on assessment of nonlinear relationships of age, MCC, and naturally occurring clusters of MCC on mortality. PMID:26562307

  17. A pilot study of a mindfulness based stress reduction program in adolescents with implantable cardioverter defibrillators or pacemakers.

    PubMed

    Freedenberg, Vicki A; Thomas, Sue A; Friedmann, Erika

    2015-04-01

    Adolescents with implantable cardioverter defibrillators (ICDs) or pacemakers (PMs) face unique challenges that can cause psychosocial distress. Psychosocial interventions are effective for adults with cardiac devices and could potentially impact adolescents' adjustment to these devices. Mindfulness Based Stress Reduction (MBSR) is a structured psycho-educational program that includes meditation, yoga, and group support and has been studied extensively among adults. This study examined the feasibility of the MBSR program for adolescents with ICDs/PMs, a population previously unexamined in the research literature. The participants completed measures of anxiety and depression (Hospital Anxiety and Depression Scale) and coping (Responses to Stress Questionnaire) at baseline and after the six-session MBSR intervention. Mean age of the cohort (n = 10) was 15 ± 3 years, 6 were male, 6 had a PM, and 4 had an ICD. Feasibility was demonstrated by successful recruitment of 10 participants, 100 % participation and completion. Anxiety decreased significantly following the intervention, with a large effect size, t[9] = 3.67, p < .01, ŋ (2) = .59. Anxiety frequency decreased from baseline to post-intervention (Fisher's exact test p = .024), and 90 % of participants reported decreased anxiety scores post-intervention. Coping skills related negatively to anxiety (r = -.65, p = .04) and depression (r = -.88, p = .001). Post-intervention, the group independently formed their own Facebook group and requested to continue meeting monthly. Although generalizability is limited due to the small sample size, this successful pilot study paves the way for larger studies to examine the efficacy of MBSR interventions in adolescents with high-risk cardiac diagnoses.

  18. Sleep Quality and Sleepiness in Persons with Implantable Cardioverter Defibrillators: Outcome from a Clinical Randomized Longitudinal Trial

    PubMed Central

    BERG, SELINA KIKKENBORG; HIGGINS, MELINDA; REILLY, CAROLYN M.; LANGBERG, JONATHAN J.; DUNBAR, SANDRA B.

    2013-01-01

    Background Patients receiving an implantable cardioverter defibrillator (ICD) report various types and degree of sleep disruptions, but little is known regarding their characteristics, duration, and associated factors. The purposes of this study were: (1) to describe the effect of a psychoeducational intervention on sleep quality and daytime sleepiness, (2) to describe patterns of sleep over time, and (3) to identify predictors of poor sleep in an ICD population. Methods A randomized longitudinal intervention trial was designed to test the effects of a psychoeducational intervention, which included a sleep education and counseling session in patients receiving their initial ICD. Patients (n = 236; 75% men; mean age 58.4 [±11.2] from the PsychoEducationAl Intervention for ICD PatiEnts (PEACE) trial comprised the study population. Variables related to sleep were measured by the Pittsburgh Sleep Quality Inventory (PSQI) and Epworth Sleepiness Scale (ESS). Results No psychoeducational intervention effects on sleep outcomes were observed. However, 67.2% of the patients reported poor sleep quality at baseline, and 56.8% had low sleep quality at 6 months based on PSQI scores >5; one-third (32.6%) were excessively sleepy based on ESS scores =10 at 6 months. Anxiety, depression, physical function, pain intensity, and pain severity were all highly correlated to each other across time. Female gender was a significant covariate for the PSQI. New York Heart Association (NYHA) class was a significant covariate for sleepiness (Epworth). Conclusions Low sleep quality and daytime sleepiness are found at time of insertion and over time in patients with ICD. Female gender, higher NYHA class, as well as two latent factors encompassing increased anxiety, depressive symptoms, and decreased physical function and increased pain, were significant predictors of poor sleep quality and sleepiness over time. These data help identify those at higher risk for sleep problems after ICD. PMID

  19. 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. PMID:10604089

  20. Development and Testing of an Intervention to Improve Outcomes for Partners Following Receipt of an Implantable Cardioverter Defibrillator in the Patient

    PubMed Central

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

    2013-01-01

    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. PMID:23107992

  1. Long-term structural failure of coaxial polyurethane implantable cardioverter defibrillator leads.

    PubMed

    Hauser, Robert G; Cannom, David; Hayes, David L; Parsonnet, Victor; Hayes, John; Ratliff, Norman; Tyers, G Frank O; Epstein, Andrew E; Vlay, Stephen C; Furman, Seymour; Gross, Jay

    2002-06-01

    Transvene models 6936/6966, a coaxial polyurethane ICD lead, may be prone to structural failure. These models comprise 54% of ICD lead failures in the authors' Multicenter Registry database. Because ICD leads perform a vital function, the clinical features, causes, and probability of Transvene 6936/6966 lead failure were determined. The Registry and United States Food and Drug Administration databases were queried for the clinical features and structural causes of the Transvene 6936/6966 lead failure, and a five-center substudy estimated the survival probability for 521 Transvene 6936/6966 implants. The mean time to failure was 4.8 +/- 2.1 years, and the estimated survival at 60 and 84 months after implant were 92% and 84%, respectively. Oversensing was the most common sign of failure (76%), and 24 patients experienced inappropriate shocks. The manufacturer's reports indicated that high voltage coil fracture and 80A polyurethane defects were the predominant causes of lead failure. Transvene models 6936 and 6966 coaxial polyurethane ICD leads are prone to failure over time. Patients who have these leads should be evaluated frequently. Additional studies are needed to identify safe management strategies. PMID:12137338

  2. Prediction of Appropriate Shocks Using 24-Hour Holter Variables and T-Wave Alternans After First Implantable Cardioverter-Defibrillator Implantation in Patients With Ischemic or Nonischemic Cardiomyopathy.

    PubMed

    Seegers, Joachim; Bergau, Leonard; Expósito, Pascal Muñoz; Bauer, Axel; Fischer, Thomas H; Lüthje, Lars; Hasenfuß, Gerd; Friede, Tim; Zabel, Markus

    2016-07-01

    In patients treated with implantable cardioverter defibrillator (ICD), prediction of both overall survival and occurrence of shocks is important if improved patient selection is desired. We prospectively studied the predictive value of biomarkers and indexes of cardiac and renal function and spectral microvolt T-wave alternans testing and 24-hour Holter variables in a population who underwent first ICD implantation. Consecutive patients in sinus rhythm with ischemic or dilated cardiomyopathy scheduled for primary or secondary prophylactic ICD implantation were enrolled. Exercise microvolt T-wave alternans and 24-hour Holter for number of ventricular premature contractions (VPCs), deceleration capacity, heart rate variability, and heart rate turbulence were done. Death of any cause and first appropriate ICD shock were defined as end points. Over 33 ± 15 months of follow-up, 36 of 253 patients (14%) received appropriate shocks and 39 of 253 patients (15%) died. Only 3 of 253 patients (1%) died after receiving at least 1 appropriate shock. In univariate analyses, New York Heart Association class, ejection fraction, N-terminal pro brain-type natriuretic peptide (NT-proBNP), renal function, ICD indication, deceleration capacity, heart rate variability, and heart rate turbulence were predictive of all-cause mortality and VPC number and deceleration capacity predicted first appropriate shock. NT-proBNP (≥1,600 pg/ml) was identified as the only independent predictor of all-cause mortality (hazard ratio 3.0, confidence interval 1.3 to 7.3, p = 0.014). In contrast, VPC number predicted appropriate shocks (hazard ratio 2.3, confidence interval 1.0 to 5.5, p = 0.047) as the only independent risk marker. In conclusion, NT-proBNP is a strong independent predictor of mortality in a typical prospective cohort of newly implanted patients with ICD, among many electrocardiographic and clinical variables studied. Number of VPCs was identified as a predictor of appropriate shocks

  3. [High incidence of isolator fractures in transvenous implantation of cardioverter defibrillators].

    PubMed

    Mewis, C; Kühlkamp, V; Dörnberger, V; Mermi, J; Seipel, L

    1997-02-01

    With the growing complexity of transvenous ICD-lead systems the incidence of lead complications might increase in comparison to usual pacemaker leads. The incidence of insulation defects of transvenous leads was determined during a mean follow-up time of 23.8 +/- 10.9 months. Among 130 transvenous ICD-patients, eight insulation-breaks in seven patients (6%) could be identified after a mean follow-up of 28 +/- 13 months. After a follow-up period of 12 months no lead defect was identified, after 24 months 96.3 +/- 1.8% of all transvenous leads were free of complications, after 36 months 87.9 +/- 6% and after 48 months in 61.2 +/- 18.7% of all leads no isolator fracture was found. In seven cases an operative revision was required. All insulation-defects were exclusively found in abdominally implanted silicone lead-systems type Endotak/CPI (Cardiac Pacemakers, Inc., USA): isolator fractures occurred in 12% of all Endotak leads used, 19% of the Endotak C models 62, 64, 72 and 74 were affected. In none of 66 implanted Transvene lead systems (Medtronic, Inc., USA) were isolator defects found. In six patients the proximal part of the sensing lead near the device was affected. All of these patients experienced potentially harmful repetitive device discharges. In one patient during elective ICD-replacement an isolation break of the proximal shock electrode was found, in another patient between the proximal and distal shock-electrode. Despite regular follow-ups with impedance-measurements, only in one case was the insulation break foreseeable. Stored electrograms were helpful to disclose insulation defects. With increasing age of the transvenous lead systems a growing number of insulation defects has to be expected. Especially the isolators of the first Endotak C models 60-74 seem to create major problems with increasing age.

  4. Prostate brachytherapy postimplant dosimetry: Automatic plan reconstruction of stranded implants

    SciTech Connect

    Chng, N.; Spadinger, I.; Morris, W. J.; Usmani, N.; Salcudean, S.

    2011-01-15

    Purpose: Plan reconstruction for permanent implant prostate brachytherapy is the process of determining the correspondence between planned and implanted seeds in postimplant analysis. Plan reconstruction informs many areas of brachytherapy quality assurance, including the verification of seed segmentation, misplacement and migration assessment, implant simulations, and the dosimetry of mixed-activity or mixed-species implants. Methods: An algorithm has been developed for stranded implants which uses the interseed spacing constraints imposed by the suture to improve the accuracy of reconstruction. Seventy randomly selected clinical cases with a mean of 23.6 (range 18-30) needles and mean density of 2.0 (range 1.6-2.6) 2.0 (range 1.6-2.6) seeds/cm{sup 3} were automatically reconstructed and the accuracy compared to manual reconstructions performed using a custom 3D graphical interface. Results: Using the automatic algorithm, the mean accuracy of the assignment relative to manual reconstruction was found to be 97.7{+-}0.5%. Fifty-two of the 70 cases (74%) were error-free; of seeds in the remaining cases, 96.7{+-}0.3% were found to be attributed to the correct strand and 97.0{+-}0.3% were correctly connected to their neighbors. Any necessary manual correction using the interface is usually straightforward. For the clinical data set tested, neither the number of seeds or needles, average density, nor the presence of clusters was found to have an effect on reconstruction accuracy using this method. Conclusions: Routine plan reconstruction of stranded implants can be performed with a high degree of accuracy to support postimplant dosimetry and quality analyses.

  5. An updated review of implantable cardioverter/defibrillators, induced anxiety, and quality of life.

    PubMed

    Bostwick, J Michael; Sola, Christopher L

    2007-12-01

    During the past 2 years the number of studies examining psychopathology and quality of life after ICD implantation has increased dramatically. Variables assessed have included recipient age, gender, and social support network. How recipients respond to having the device, particularly after experiencing firing, has been evaluated in light of new depression and anxiety disorder diagnoses as well as premorbid personality structure. Now the picture of what is known is, if anything, cloudier than it was 2 years ago, with little definitive and much contradictory data emerging in most of these categories. It still seems clear that in a significant minority of ICD recipients the device negatively affects quality of life, probably more so if it fires. Education about life with the device before receiving it remains paramount. Reports continue to appear of patients developing new-onset diagnosable anxiety disorders such as panic and posttraumatic stress disorder. Until recently the strongest predictors of induced psychopathology were considered to be the frequency and recency of device firing. It now seems that preimplantation psychologic variables such as degree of optimism or pessimism and an anxious personality style may confer an even greater risk than previously thought. Certainly many variables factor into the induction of psychopathology in these patients. Among these factors are age, gender, and perception of control of shocks, as well as the predictability of shocks and psychologic attributions made by the patient regarding the device. Another source of variability is this population's medical heterogeneity. Some patients receive ICDs after near-death experiences; others get them as anticipatory prophylaxis. Some have longstanding and entrenched heart disease; others were apparently healthy before sudden dangerous arrhythmias. Diagnoses as diverse as myocardial infarction in the context of advanced coronary artery disease and dilated cardiomyopathy after acute viral

  6. Circadian variations in the occurrence of ventricular tachyarrhythmias in patients with implantable cardioverter defibrillators.

    PubMed

    Kozák, Milan; Krivan, Lubomír; Semrád, Borivoj

    2003-03-01

    A circadian distribution has been demonstrated in episodes of sudden cardiac death, acute myocardial infarction, ventricular premature complexes, heart rate variability, and ventricular tachyarrhythmias. The aim of this study was to evaluate the circadian distribution of ventricular tachyarrhythmia episodes in a population of ICD patients. Data were gathered from 72 patients (55 men, 17 women; mean age 62.7 +/- 12.2 years, mean LVEF 0.0037 +/- 0.0011) with ICDs implanted for standard indications. Patients were followed every 3 months over a mean period of 21 +/- 12.8 months. At each examination, symptoms at arrhythmia onset and perception of ICD therapy were recorded, and the ICD memory was interrogated. During follow-up, 1,023 episodes' of malignant ventricular arrhythmias were detected and effectively terminated, 506 of which were fully analyzed. A morning peak in ventricular tachyarrhythmias was demonstrated between 7:00 and 11:00 AM, and an afternoon peak between 6:00 and 7:00 PM. A significantly lower occurrence of VT was observed at 1:00 AM and between 4:00 and 6:00 AM. A circadian distribution in the occurrence of ventricular tachycardias was found. The three striking features of the data are: the early morning peak (about three hours after waking up), relatively stable incidence throughout waking hours, and decline in incidence in the previous period. PMID:12698674

  7. Cognitive and Behavioral Treatments for Anxiety and Depression in a Patient with an Implantable Cardioverter Defibrillator (ICD): A Case Report and Clinical Discussion

    PubMed Central

    Sears, Samuel F.; Conti, Jamie B.

    2011-01-01

    Implantable cardioverter-defibrillators (ICDs) are the treatment of choice for patients at risk for potentially life threatening arrhythmias. The associated stress of living with an implanted device and receiving ICD shock therapy has been noted to exert a psychological toll on the individual patient and family. Anxious and depressive symptomatology is frequently reported by these patients, thus creating a demand for tailored psychological interventions for this population. The current case report describes the components, delivery, and effectiveness of a targeted treatment approach for anxiety and depression in an individual with an ICD. Test results and interview data revealed significant improvements in multiple domains of cognitive, emotional, and behavioral functioning. Improvements in marital relations were also achieved. These treatment effects were maintained at follow-up and in the context of acute, medical stressors. Future clinical and research directions are also discussed. PMID:19404725

  8. Association Between Comorbidities and Outcomes in Heart Failure Patients With and Without an Implantable Cardioverter-Defibrillator for Primary Prevention

    PubMed Central

    Khazanie, Prateeti; Hellkamp, Anne S; Fonarow, Gregg C; Bhatt, Deepak L; Masoudi, Frederick A; Anstrom, Kevin J; Heidenreich, Paul A; Yancy, Clyde W; Curtis, Lesley H; Hernandez, Adrian F; Peterson, Eric D; Al-Khatib, Sana M

    2015-01-01

    Background Implantable cardioverter-defibrillator (ICD) therapy is associated with improved outcomes in patients with heart failure (HF), but whether this association holds among older patients with multiple comorbid illnesses and worse HF burden remains unclear. Methods and Results Using the National Cardiovascular Data Registry’s ICD Registry and the Get With The Guidelines–Heart Failure (GWTG-HF) registry linked with Medicare claims, we examined outcomes associated with primary-prevention ICD versus no ICD among HF patients aged ≥65 years in clinical practice. We included patients with an ejection fraction ≤35% who received (ICD Registry) and who did not receive (GWTG-HF) an ICD. Compared with patients with an ICD, patients in the non-ICD group were older and more likely to be female and white. In matched cohorts, the 3-year adjusted mortality rate was lower in the ICD group versus the non-ICD group (46.7% versus 55.8%; adjusted hazard ratio [HR] 0.76; 95% CI 0.69 to 0.83). There was no associated difference in all-cause readmission (HR 0.99; 95% CI 0.92 to 1.08) but a lower risk of HF readmission (HR 0.88; 95% CI 0.80 to 0.97). When compared with no ICD, ICDs were also associated with better survival in patients with ≤3 comorbidities (HR 0.77; 95% CI 0.69 to 0.87) and >3 comorbidities (HR 0.77; 95% CI 0.64 to 0.93) and in patients with no hospitalization for HF (HR 0.75; 95% CI 0.65 to 0.86) and at least 1 prior HF hospitalization (HR 0.69; 95% CI 0.58 to 0.82). In subgroup analyses, there were no interactions between ICD and mortality risk for comorbidity burden (P=0.95) and for prior HF hospitalization (P=0.46). Conclusion Among older HF patients, ICDs for primary prevention were associated with lower risk of mortality even among those with high comorbid illness burden and prior HF hospitalization. PMID:26251283

  9. A case-crossover analysis of particulate air pollution and cardiac arrhythmia in patients with implantable cardioverter defibrillators.

    PubMed

    Rich, Kira E; Petkau, John; Vedal, Sverre; Brauer, Michael

    2004-06-01

    We investigated the relationship between air pollution and incidence of cardiac arrhythmia in a study of patients with implantable cardioverter defibrillators (ICDs). Thirty-four patients (ages 15-85 yr, 80% male) with ICDs residing in the Vancouver, Canada, area were included in the analyses, representing all patients attending the 2 ICD clinics in the study region who had recorded at least 1 ICD discharge during the 14 February to 31 December 2000 study period. Air pollutant (PM(2.5), PM(10), SO(4)(2-), elemental carbon [EC], organic carbon [OC], O(3), SO(2), NO(2), and CO) concentrations on days for which ICD discharges were observed ("case days") were compared to concentrations on control days in case-crossover analyses. Control days were selected symmetrically, 7 days before and after each case day. ICD discharges occurring within 72 h of 1 another were grouped and considered as 1 discharge event. Temperature, relative humidity, barometric pressure, rainfall, and wind speed were included simultaneously as covariates. Sensitivity analyses examined the effect of grouping ICD discharges, of including meteorological variables, and of excluding discharges that were considered inappropriate by a cardiologist. As in previous studies, mean concentrations and interquartile ranges of air pollutants in Vancouver were low (e.g., PM(2.5) mean = 8.2 microg/m(3)). Although in general there were no statistically significant results, there were trends that might indicate associations between pollutants and ICD discharges. Odds ratios (OR) were consistently higher in summer than in winter (e.g., lag 0 per interquartile range increase in EC: 1.09 [0.86-1.37] vs. 0.61 [0.31-1.18]) and, in general, the highest ORs were observed for same-day effects. The one major exception was the observation of high ORs for ozone in winter (e.g., lag 1: 2.27 [0.67-7.66]). While an OR of 1.55 (0.51-4.70) was observed in summer at lag 0 for PM(10), no indications of positive associations were

  10. 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.

  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. 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

  13. 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

  14. Single-incision and single-element array electrode to lower the defibrillation threshold.

    PubMed

    Kühlkamp, V; Khalighi, K; Dörnberger, V; Ziemer, G

    1997-10-01

    Occasional patients have excessive defibrillation energy requirements despite appropriate transvenous defibrillation lead position and the use of biphasic shocks. A single-element subcutaneous array electrode was implanted in 2 patients with a high defibrillation threshold. The array electrode was implanted through the same infraclavicular incision that was used for implantation of the transvenous lead. The defibrillation threshold decreased from 30 J to 15 J and from 24 J to 9 J with the subcutaneous array electrode.

  15. Pacemakers and Implantable Defibrillators

    MedlinePlus

    ... heart rate or rhythm. It means that your heart beats too quickly, too slowly, or with an irregular ... rhythms. It uses electrical pulses to prompt the heart to beat at a normal rate. It can speed up ...

  16. Implantable Cardioverter Defibrillator

    MedlinePlus

    ... How Does an ICD Work During ICD Surgery After ICD Surgery What Are the Risks Lifestyle Clinical Trials Links Related Topics Arrhythmia Heart Attack How the Heart Works Pacemakers Sudden Cardiac Arrest Send a link to NHLBI to ...

  17. 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 ...

  18. Implantable cardioverter-defibrillator

    MedlinePlus

    ... food tips Heart attack - discharge Heart disease - risk factors Heart failure ... Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed ...

  19. 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

  20. Implantable cardioverter-defibrillator therapy in a 34-year-old patient with eating disorders and after the third sudden cardiac arrest.

    PubMed

    Piotrowicz, Ewa; Orzechowski, Piotr; Bilinska, Maria; Przybylski, Andrzej; Szumowski, Lukasz; Piotrowicz, Ryszard

    2015-03-01

    Eating disorders (ED) such as anorexia nervosa and bulimia are psychiatric diseases associated with the highest mortality rate of any other psychiatric disorders. More recently, long-term outcome studies with follow-up of over 20 years report a mortality of between 15% and 18% (Casiero and Frishman, Cardiol Rev 14(5), 227, 2006). The sudden death secondary to arrhythmias is often the cause of death in these patients (Casiero and Frishman, Cardiol Rev 14(5), 227, 2006). A case of life-threatening ventricular arrhythmia (VA) in a patient with ED is presented. Clinical records (cardiologic, psychiatric), electrocardiograms, echocardiogram, coronary angiogram, cardiac magnetic resonance, and endocrine diagnostics were performed. Finally a cardioverter-defibrillator (ICD) was implanted in the patient after her third cardiac arrest. An optimal approach to antiarrhythmic therapy in such patients is a real challenge for a cardiologist.

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

    PubMed

    Sodhi, Sandeep S; Cedars, Ari M

    2015-08-01

    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

  2. Longevity of implantable cardioverter-defibrillators for cardiac resynchronization therapy in current clinical practice: an analysis according to influencing factors, device generation, and manufacturer

    PubMed Central

    Landolina, Maurizio; Curnis, Antonio; Morani, Giovanni; Vado, Antonello; Ammendola, Ernesto; D'onofrio, Antonio; Stabile, Giuseppe; Crosato, Martino; Petracci, Barbara; Ceriotti, Carlo; Bontempi, Luca; Morosato, Martina; Ballari, Gian Paolo; Gasparini, Maurizio

    2015-01-01

    Aims Device replacement at the time of battery depletion of implantable cardioverter-defibrillators (ICDs) may carry a considerable risk of complications and engenders costs for healthcare systems. Therefore, ICD device longevity is extremely important both from a clinical and economic standpoint. Cardiac resynchronization therapy defibrillators (CRT-D) battery longevity is shorter than ICDs. We determined the rate of replacements for battery depletion and we identified possible determinants of early depletion in a series of patients who had undergone implantation of CRT-D devices. Methods and results We retrieved data on 1726 consecutive CRT-D systems implanted from January 2008 to March 2010 in nine centres. Five years after a successful CRT-D implantation procedure, 46% of devices were replaced due to battery depletion. The time to device replacement for battery depletion differed considerably among currently available CRT-D systems from different manufacturers, with rates of batteries still in service at 5 years ranging from 52 to 88% (log-rank test, P < 0.001). Left ventricular lead output and unipolar pacing configuration were independent determinants of early depletion [hazard ratio (HR): 1.96; 95% 95% confidence interval (CI): 1.57–2.46; P < 0.001 and HR: 1.58, 95% CI: 1.25–2.01; P < 0.001, respectively]. The implantation of a recent-generation device (HR: 0.57; 95% CI: 0.45–0.72; P < 0.001), the battery chemistry and the CRT-D manufacturer (HR: 0.64; 95% CI: 0.47–0.89; P = 0.008) were additional factors associated with replacement for battery depletion. Conclusion The device longevity at 5 years was 54%. High left ventricular lead output and unipolar pacing configuration were associated with early battery depletion, while recent-generation CRT-Ds displayed better longevity. Significant differences emerged among currently available CRT-D systems from different manufacturers. PMID:25976906

  3. 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 Central

    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

    2015-01-01

    Sudden cardiac death (SCD) is a leading cause of mortality in patients with cardiomyopathy. While angiotensin converting enzyme inhibitors (ACEi) and receptor blockers (ARB) 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 (GRADE) study which included subjects with an ejection fraction of ≤30% and ICDs. Treatment with ACEi/ARB versus no ACEi/ARB was physician dependent. There were 1509 patients (mean age [SD] 63[12] years, 80% male, mean [SD] EF 21% [6%]) with 1213 (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%, 18.5% vs. 13.2%, 27.5%, and 32.0% (RR= 0.61[0.43–0.86], p =0.005). Among patients with GFR >60 and 30–60 ml/min/1.73m2, those on no-ACEi/ARB were at 45% and 77% increased risk of ICD shock as compared to 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/1.73m2, and with neutral effect among those GFR <30 ml/min/1.73m2. PMID:25682436

  4. Long-term follow up of patients with implantable cardioverter-defibrillators and mild, moderate, or severe impairment of left ventricular function.

    PubMed Central

    Trappe, H. J.; Wenzlaff, P.; Pfitzner, P.; Fieguth, H. G.

    1997-01-01

    OBJECTIVE: To determine whether patients with life threatening ventricular tachyarrhythmias, impaired left ventricular function, and severe heart failure will benefit from implantable cardioverter-defibrillator (ICD) treatment. DESIGN: 410 patients were followed up after ICD implant. Left ventricular function was assessed by the New York Heart Association (NYHA) functional class of heart failure: 50 patients (12%) were in NYHA I-II, 151 (37%) in NYHA II, 117 (29%) in NYHA II-III, and 92 (22%) in NYHA III. Epicardial ICD implantation was performed in 209 patients (51%) and 201 patients (49%) received non-thoracotomy ICDs. RESULTS: Perioperatively, 12 patients (3%) died, more often after epicardial ICD implant (11/209 patients, 5%) than after transvenous implant (1/201 patients, < 1%) (P < 0.05). During a mean (SD) follow up of 28 (24) months (range < 1 to 114 months), 90 patients (23%) died: nine (2%) died from sudden arrhythmia; five (1%) also died suddenly but probably not from arrhythmic causes; 55 (14%) died from cardiac causes (congestive heart failure, myocardial reinfarction); 21 (5%) died from non-cardiac causes. The three year, five year, and seven year survival was 92-96% for arrhythmic mortality in NYHA class I, II and III, compared to a three year survival of 94% and a five year and seven year survival of 84% for patients in NYHA class II-III. 338 patients (82%) received ICD shocks (21 (SD 43) shocks per patient); patients in NYHA class II (83%), class II-III (84%), and class III (90%) received ICD discharges more often than those in class I-II (64%) (P < 0.05). The mean (SD) time interval between ICD implant and the first ICD shock was shorter in NYHA class II (16 (17) months), class II-III (19 (27) months), and class III (16 (19) months) than in class 0-I (22 (24) months) (P < 0.05). CONCLUSIONS: Patients with mild, moderate, and severe left ventricular dysfunction benefit from ICD treatment and these patients survive for a considerable time after the

  5. 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

    2014-01-01

    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

  6. 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

  7. 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

  8. 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

  9. Design and Methods for a Pilot Study of a Phone-Delivered, Mindfulness-Based Intervention in Patients with Implantable Cardioverter Defibrillators

    PubMed Central

    Salmoirago-Blotcher, Elena; Carmody, James; Yeh, Gloria; Crawford, Sybil; Rosenthal, Lawrence; Ockene, Ira

    2012-01-01

    Background. Meditation practices are associated with a reduction in adrenergic activity that may benefit patients with severe cardiac arrhythmias. This paper describes the design and methods of a pilot study testing the feasibility of a phone-delivered mindfulness-based intervention (MBI) for treatment of anxiety in patients with implantable cardioverter defibrillators (ICDs). Design and Methods. Consecutive, clinically stable outpatients (n = 52) will be screened for study eligibility within a month of an ICD-related procedure or ICD shock and will be randomly assigned to MBI or to usual care. MBI patients will receive eight weekly individual phone sessions based on two mindfulness practices (awareness of breath and body scan) plus home practice with a CD for 20 minutes daily. Patients assigned to usual care will be offered the standard care planned by the hospital. Assessments will occur at baseline and at the completion of the intervention (between 9 and 12 weeks after randomization). The primary study outcome is feasibility; secondary outcomes include anxiety, mindfulness, and number of administered shocks during the intervention period. Conclusions. If proven feasible and effective, phone-delivered mindfulness-based interventions could improve psychological distress in ICD outpatients with serious cardiovascular conditions. PMID:22536294

  10. Integrated approach for smart implantable cardioverter defibrillator (ICD) device with real time ECG monitoring: use of flexible sensors for localized arrhythmia sensing and stimulation

    PubMed Central

    Puri, Munish; Chapalamadugu, Kalyan C.; Miranda, Aimon C.; Gelot, Shyam; Moreno, Wilfrido; Adithya, Prashanth C.; Law, Catherine; Tipparaju, Srinivas M.

    2013-01-01

    Arrhythmias are the most common cause of death associated with sudden death and are common in US and worldwide. Cardiac resynchronization therapy (CRT), evolving from pacemakers and development of implantable cardioverter defibrillator (ICD), has been adopted for therapeutic use and demonstrated benefits in patients over the years due to its design and intricate functionality. Recent research has been focused on significant design improvement and efforts are dedicated toward device size reduction, weight and functionality in commercially available ICD's since its invention in the 1960's. Commercially available CRT-D has shown advancement on both clinical and technical side. However, improved focus is required on the device miniaturization, technologically supported and integrated wireless based system for real time heart monitoring electrocardiogram (ECG). In the present report a concise overview for the state-of-the art technology in ICDs and avenues for future development are presented. A unique perspective is also included for ICD device miniaturization and integration of flexible sensing array. Sensor array integration along with its capabilities for identifying localized arrhythmia detection and targeted stimulation for enhancing ICD device capabilities is reviewed. PMID:24167492

  11. Improving the appropriateness of sudden arrhythmic death primary prevention by implantable cardioverter-defibrillator therapy in patients with low left ventricular ejection fraction. Point of view

    PubMed Central

    Disertori, Marcello; Gulizia, Michele M.; Casolo, Giancarlo; Delise, Pietro; Di Lenarda, Andrea; Di Tano, Giuseppe; Lunati, Maurizio; Mestroni, Luisa; Salerno-Uriarte, Jorge; Tavazzi, Luigi

    2016-01-01

    It is generally accepted that the current guidelines for the primary prevention of sudden arrhythmic death, which are based on ejection fraction, do not allow the optimal selection of patients with low left ventricular ejection fraction of ischemic and nonischemic etiology for implantation of a cardioverter-defibrillator. Ejection fraction alone is limited in both sensitivity and specificity. An analysis of the risk of sudden arrhythmic death with a combination of multiple tests (ejection fraction associated with one or more arrhythmic risk markers) could partially compensate for these limitations. We propose a polyparametric approach for defining the risk of sudden arrhythmic death using ejection fraction in combination with other clinical and arrhythmic risk markers (i.e. late gadolinium enhancement cardiac magnetic resonance, T-wave alternans, programmed ventricular stimulation, autonomic tone, and genetic testing) that have been validated in nonrandomized trials. In this article, we examine these approaches to identify three subsets of patients who cannot be comprehensively assessed by the current guidelines: patients with ejection fraction of 35% or less and a relatively low risk of sudden arrhythmic death despite the ejection fraction value; patients with ejection fraction of 35% or less and high competitive risk of death due to evolution of heart failure or noncardiac causes; and patients with ejection fraction between 35 and 45% with relatively high risk of sudden arrhythmic death despite the ejection fraction value. PMID:26895401

  12. 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

  13. 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.

  14. 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). PMID:25682436

  15. 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.

  16. [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.

  17. Automated External Defibrillator

    MedlinePlus

    ... from the NHLBI on Twitter. What Is an Automated External Defibrillator? An automated external defibrillator (AED) is a portable device that ... Institutes of Health Department of Health and Human Services USA.gov

  18. Perceptions of an implantable cardioverter-defibrillator: A qualitative study of families with a history of sudden life-threatening cardiac events and recommendations to improve care

    PubMed Central

    Linder, Jarrett; Hidayatallah, Nadia; Stolerman, Marina; McDonald, Thomas V.; Marion, Robert; Walsh, Christine; Dolan, Siobhan

    2014-01-01

    Objective To identify major concerns associated with implantable cardioverter-defibrillators (ICDs) and to provide recommendations to adult and pediatric physicians involved in the care of patients with ICDs. Background Cardiac ion channelopathies are a well-recognized cause of sudden cardiac death in infants, children, adolescents, and young adults. ICDs are effective in preventing sudden death from fatal arrhythmias in patients with known cardiac channelopathies. There is a paucity of research on the effect of ICDs on quality of life in patients with cardiac channelopathy diagnoses, especially young patients. Methods A qualitative study interviewing patients and families affected by inherited arrhythmias was conducted. Fifty participants with personal or family histories of cardiac events or sudden death were interviewed individually or in focus groups by clinical psychologists. All interviews were transcribed verbatim and then analyzed and coded based on current qualitative research theory to identify themes related to the research question. Twenty-four participants discussed ICDs in their interviews. Results Participants reported concerns about ICDs, and these concerns were categorized into six themes: (1) comprehension and physician-patient communication; (2) anxiety; (3) restrictions and fallacies; (4) complications; (5) utility; and (6) alternative therapy. Participants noted communication breakdowns between providers and their colleagues, and between providers and their patients. Participants and their families experienced many different forms of anxiety, including worry about the aesthetics of the ICDs and fears of being shocked. Multiple restrictions, fallacies, and complications were also cited. Conclusion Interview themes were used to formulate recommendations for counseling and educating patients with ICDs. PMID:25383067

  19. A Novel Method for Epicardial Defibrillator Lead Placement in Young Children: Coil Between the Great Arteries.

    PubMed

    Murthy, Raghav; Williams, Matthew R; Perry, James C; Shepard, Suzanne; DiBardino, Daniel

    2016-10-01

    The primary and secondary prevention of sudden cardiac death resulting from malignant arrhythmia, channelopathy, and hypertrophic cardiomyopathy often requires the implantation of automatic internal cardiac defibrillators (AICDs) in the pediatric population. In young patients, the small size of the systemic veins, complex anatomy of congenital heart disease, and body habitus often preclude safe and durable transvenous placement of the AICD coil, requiring innovative methods to circumvent this problem. This report describes the technique used at Rady Children's Hospital San Diego/UCSD for the epicardial placement of an ICD system with a transvenous ICD coil placed between the aorta and pulmonary artery, thereby producing a stable location and excellent coil-to-can vector for successful defibrillation. PMID:27645989

  20. Cost–consequence analysis of daily continuous remote monitoring of implantable cardiac defibrillator and resynchronization devices in the UK

    PubMed Central

    Burri, Haran; Sticherling, Christian; Wright, David; Makino, Koji; Smala, Antje; Tilden, Dominic

    2013-01-01

    Aims The need for ongoing and lifelong follow-up (FU) of patients with cardiac implantable electric devices (CIED) requires significant resources. Remote CIED management has been established as a safe alternative to conventional periodical in-office FU (CFU). An economic model compares the long-term cost and consequences of using daily Home Monitoring® (HM) instead of CFU. Methods and results A cost–consequence evaluation comparing HM vs. CFU was performed using a Markov cohort model and data relating to events and costs identified via a systematic review of the literature. The model is conservative, without assuming a reduction of cardiovascular events by HM such as decompensated heart failure or mortality, or considering cost savings such as for transportation. Also cost savings due to an improved timing of elective device replacement, and fewer FU visits needed in patients near device replacement are not considered. Over 10 years, HM is predicted to be cost neutral at about GBP 11 500 per patient in either treatment arm, with all costs for the initial investment into HM and fees for ongoing remote monitoring included. Fewer inappropriate shocks (−51%) reduce the need for replacing devices for battery exhaustion (−7%); the number of FU visits is predicted to be halved by HM. Conclusion From a UK National Health Service perspective, HM is cost neutral over 10 years. This is mainly accomplished by reducing the number of battery charges and inappropriate shocks, resulting in fewer device replacements, and by reducing the number of in-clinic FU visits. PMID:23599169

  1. 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.

  2. 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.

  3. Development and feasibility testing of decision support for patients who are candidates for a prophylactic implantable defibrillator: a study protocol for a pilot randomized controlled trial

    PubMed Central

    2013-01-01

    Background Patients, identified to be at risk for but who have never experienced a potentially lethal cardiac arrhythmia, have the option of receiving an implantable cardioverter defibrillator (ICD) as prophylaxis against sudden cardiac death - a primary prevention indication. In Canada, there is no clear framework to support patients’ decision-making for these devices. Decision support, using a decision aid, could moderate treatment-related uncertainty and prepare patients to make well-informed decisions. Patient decision aids provide information on treatment options, risks, and benefits, to help patients clarify their values for outcomes of treatment options. The objectives of this research are: 1) develop a decision aid, 2) evaluate the decision aid, and 3) determine the feasibility of conducting a trial. Methods/design A development panel comprised of the core investigative team, health service researchers, decision science experts, cardiovascular healthcare practitioners, and ICD patient representatives will collaborate to provide input on the content and format of the aid. To generate probabilities to include in the aid, we will synthesize primary prevention ICD evidence. To obtain anonymous input about the facts and content, we will employ a modified Delphi process. To evaluate the draft decision aid will invite ICD patients and their families (n = 30) to rate its acceptability. After we evaluate the aid, to determine the feasibility, we will conduct a feasibility pilot randomized controlled trial (RCT) in new ICD candidates (n = 80). Participants will be randomized to receive a decision aid prior to specialist consultation versus usual care. Results from the pilot RCT will determine the feasibility of research processes; inform sample size calculation, measure decision quality (knowledge, values, decision conflict) and the influence of health related quality of life on decision-making. Discussion Our study seeks to develop a decision aid, for patients

  4. A patch in the pectoral position lowers defibrillation threshold.

    PubMed

    Karasik, P; Solomon, A; Verdino, R; Moore, H; Rodak, D; Hannan, R; Fletcher, R

    1997-06-01

    Implantable pacemaker cardioverter defibrillators are now available with biphasic waveforms, which have been shown to markedly improve defibrillation thresholds (DFTs). However, in a number of patients the DFT remains high. Also, DFT may increase after implantation, especially if antiarrhythmic drugs are added. We report on the use of a subcutaneous patch in the pectoral position in 15 patients receiving a transvenous defibrillator as a method of easily reducing the DFT. A 660-mm2 patch electrode was placed beneath the generator in a pocket created on the pectoral fascia. The energy required for defibrillation was lowered by 56% on average, and the system impedance was lowered by a mean of 25%. This maneuver allowed all patients to undergo a successful implant with adequate safety margin.

  5. 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.

  6. 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. PMID:27676160

  7. 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.

  8. Subcutaneous Implantable Cardioverter-Defibrillator

    MedlinePlus

    ... discriminator functions and lacks antitachycardia pacing. Expanded Programmability Programming that allows lower shock energies and the ability ... the original device and placed in a new one. Postprocedural hospitalization is occasionally needed. Replacement procedures can ...

  9. 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

  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. Defibrillator/monitor/pacemakers.

    PubMed

    2003-05-01

    Defibrillator/monitors allow operators to assess and monitor a patient's ECG and, when necessary, deliver a defibrillating shock to the heart. When integral noninvasive pacing is added, the device is called a defibrillator/monitor/pacemaker. In this Evaluation, we present our findings for two newly evaluated models, the Welch Allyn PIC 50 and the Zoll M Series CCT, and we summarize our findings for the previously evaluated models that are still on the market. We rate the models for the following applications: general crash-cart use, in-hospital transport use, and emergency medical service (EMS) use.

  13. 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

  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. Effect of cardiac resynchronization therapy with implantable cardioverter defibrillator versus cardiac resynchronization therapy with pacemaker on mortality in heart failure patients: results of a high-volume, single-centre experience

    PubMed Central

    Kutyifa, Valentina; Geller, Laszlo; Bogyi, Peter; Zima, Endre; Aktas, Mehmet K; Ozcan, Emin Evren; Becker, David; Nagy, Vivien Klaudia; Kosztin, Annamaria; Szilagyi, Szabolcs; Merkely, Bela

    2014-01-01

    Aims There are limited and contradictory data on the effects of CRT with implantable cardioverter defibrillator (CRT-D) on mortality as compared with CRT with pacemaker (CRT-P). Methods and results We evaluated the long-term outcome of patients implanted with a CRT-D or CRT-P device in our high-volume single-centre experience. Data on all-cause mortality were derived from clinic visits and the Hungarian National Healthcare Fund Death Registry. Kaplan–Meier survival analyses and multivariate Cox regression models were used to evaluate all-cause mortality in patients with CRT-D vs. CRT-P, stratified by the aetiology of cardiomyopathy. From 2000 to 2011, 1122 CRT devices, 693 CRT-P (LVEF 28.2 ± 7.4%) and 429 CRT-D (LVEF 27.6 ± 6.4%), were implanted at our centre. During the median follow-up of 28 months, 379 patients died from any cause, 250 patients (36%) with an implanted CRT-P and 129 patients (30%) with an implanted CRT-D. There was no evidence of mortality benefit in patients implanted with a CRT-D compared with a CRT-P in the total cohort [hazard ratio (HR) 0.98, 95% confidence interval (CI) 0.73–1.32, P = 0.884]. In patients with ischaemic cardiomyopathy, CRT-D treatment was associated with a significant 30% risk reduction in all-cause mortality compared with an implanted CRT-P (HR 0.70, 95% CI 0.51–0.97, P = 0.03). In non-ischaemic patients, there was no mortality benefit of CRT-D over CRT-P (HR 0.98, 95% CI 0.73–1.32, P = 0.894, interaction P-value = 0.15). Conclusions In heart failure patients with ischaemic cardiomyopathy, CRT-D was associated with a mortality benefit compared with CRT-P, but no benefit of CRT-D over CRT-P in mortality was observed in non-ischaemic cardiomyopathy. PMID:25379962

  16. Towards Low Energy Atrial Defibrillation.

    PubMed

    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 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

  17. 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

  18. 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

  19. 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

  20. [The Wearable Cardioverter-Defibrillator (WCD)].

    PubMed

    Helms, Thomas M; Müller, A; Schwab, J O; Bänsch, D; Karle, C; Klingenheben, T; Zugck, C; Perings, C

    2015-06-01

    While the implantable cardioverter-defibrillator (ICD) has been proven to be the best choice for patients with long-term risk for sudden cardiac arrest/sudden cardiac death (SCA/SCD), the question is how to manage patients with only temporary risk, e.g., during the guidelines-recommended waiting period until the decision for an ICD can be made. These patient groups should be monitored around the clock to guarantee a lifesaving shock within a few minutes, if necessary.These conditions can be accomplished by the wearable cardioverter-defibrillator (WCD) in the outpatient sector. The WCD is worn on the skin and consists of four nonadhesive ECG electrodes as well as three defibrillation electrodes-two at the back and one at the front-embedded in a garment. The defibrillation unit is connected via a cord and can be worn over the shoulder or on a belt. Cardiac events can be recorded and retrospectively analyzed by the treating physician.The WCD is a safe and effective measure to terminate potentially lethal ventricular tachycardia and ventricular fibrillation. It may be used early after myocardial infarction with reduced left ventricular ejection fraction (LVEF), as well as for patients with acute heart failure in nonischemic cardiomyopathy with uncertain cause and prognosis. In addition, it may be used for patients waiting for heart transplantation, for patients who cannot be implanted an ICD due to comorbidities, and for patients after explantation of their ICD, e.g., because of infection until reimplantation.One may expect that risk stratification of patients with the WCD will lead to even better selection for ICD use. PMID:25939989

  1. 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

  2. Defibrillator/monitor/pacemakers.

    PubMed

    2005-06-01

    In this Evaluation, we present our test results and ratings for two newly evaluated defibrillator/monitor/pacemakers--the Medtronic ERS Lifepak 20 and the Philips HeartStart MRx. We also summarize and update our findings for eight previously evaluated models that are still on the market. We rate the models based on their desirability for in-hospital applications, such as general crash-cart use and in-hospital transport use, and for prehospital applications, specifically emergency medical service (EMS) use. The primary function of the devices examined in this study is to allow operators to assess and monitor a patient's ECG and, when necessary, deliver a defibrillating shock to the heart. However, currently available models can also be equipped to do much more during a resuscitation attempt - from monitoring multiple physiologic parameters to providing noninvasive pacing capability to functioning as an automated external defibrillator (AED). Our testing examined all these capabilities to help hospital and EMS purchasers make effective selection decisions.

  3. 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

  4. Sudden and Fatal Malfunction of a Durata Defibrillator Lead due to External Insulation Failure.

    PubMed

    Shah, Anand D; Hirsh, David S; Langberg, Jonathan J

    2016-01-01

    Defibrillator lead malfunction can be a disastrous complication, leading to loss of protection from sudden cardiac death in a high-risk patient population. Recognition of lead-specific risk for failure can assist in development of focused screening or surveillance, as in the case of the Riata lead (St. Jude Medical, St. Paul, MN, USA) or the Sprint Fidelis lead (Medtronic Inc., Minneapolis, MN, USA). A case of defibrillation failure secondary to a Durata lead insulation failure is presented. A brief review of the literature and current St. Jude Medical implantable cardiac defibrillator lead design is presented. Identification of arcing is identified as a potential sign of catastrophic insulation failure.

  5. 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.

  6. Efficacy of metoprolol and sotalol in the prevention of recurrences of sustained ventricular tachyarrhythmias in patients with an implantable cardioverter defibrillator.

    PubMed

    Kettering, Klaus; Mewis, Christian; Dörnberger, Volker; Vonthein, Reinhard; Bosch, Ralph F; Kühlkamp, Volker

    2002-11-01

    ICDs provide protection against sudden cardiac death in patients with life-threatening ventricular arrhythmias. Nevertheless, most ICD recipients receive adjunctive antiarrhythmic drug therapy to reduce the number of recurrent episodes and ICD discharges. The aim of the study was to compare the efficacy of metoprolol and d,l-sotalol in preventing VT/VF recurrences in patients with an ICD in a prospective, randomized trial. One hundred patients (83 men, 17 women; mean age 59 years, SD +/- 11 years) were randomized to receive metoprolol or sotalol after implantation of an ICD. There were no significant differences between the two groups with regard to age, sex, underlying cardiac disease, left ventricular ejection fraction, NYHA class assessment and clinical arrhythmia. The median follow-up was 728 days (25th percentile: 530 days, 75th percentile: 943 days) in the metoprolol group and 727 days (25th percentile: 472 days, 75th percentile: 1,223 days) in the sotalol group (P = 0.52). Thirty-three patients treated with metoprolol and 30 patients receiving sotalol had at least one episode during the follow-up. Event-free survival curves were generated for the two treatment arms using the Kaplan-Meier method and showed no significant difference (P = 0.68). Eight patients treated with metoprolol and six patients treated with sotalol died during follow-up. Total mortality was not significantly different between the two study groups (P = 0.43). Metoprolol is as efficacious as sotalol in preventing VT/VF recurrences in patients with an ICD.

  7. Pacemaker and Defibrillator Lead Extraction

    MedlinePlus

    ... to cure the infection without completely removing all hardware from the body. This requires removal of the ... Footnotes References Figures & Tables Info & Metrics eLetters Article Tools Print Citation Tools Pacemaker and Defibrillator Lead Extraction ...

  8. AUTOMATISM.

    PubMed

    MCCALDON, R J

    1964-10-24

    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".

  9. Optimizing defibrillation waveforms for ICDs.

    PubMed

    Kroll, Mark W; Swerdlow, Charles D

    2007-04-01

    While no simple electrical descriptor provides a good measure of defibrillation efficacy, the waveform parameters that most directly influence defibrillation are voltage and duration. Voltage is a critical parameter for defibrillation because its spatial derivative defines the electrical field that interacts with the heart. Similarly, waveform duration is a critical parameter because the shock interacts with the heart for the duration of the waveform. Shock energy is the most often cited metric of shock strength and an ICD's capacity to defibrillate, but it is not a direct measure of shock effectiveness. Despite the physiological complexities of defibrillation, a simple approach in which the heart is modeled as passive resistor-capacitor (RC) network has proved useful for predicting efficient defibrillation waveforms. The model makes two assumptions: (1) The goal of both a monophasic shock and the first phase of a biphasic shock is to maximize the voltage change in the membrane at the end of the shock for a given stored energy. (2) The goal of the second phase of a biphasic shock is to discharge the membrane back to the zero potential, removing the charge deposited by the first phase. This model predicts that the optimal waveform rises in an exponential upward curve, but such an ascending waveform is difficult to generate efficiently. ICDs use electronically efficient capacitive-discharge waveforms, which require truncation for effective defibrillation. Even with optimal truncation, capacitive-discharge waveforms require more voltage and energy to achieve the same membrane voltage than do square waves and ascending waveforms. In ICDs, the value of the shock output capacitance is a key intermediary in establishing the relationship between stored energy-the key determinant of ICD size-and waveform voltage as a function of time, the key determinant of defibrillation efficacy. The RC model predicts that, for capacitive-discharge waveforms, stored energy is minimized

  10. Use of automated external defibrillators in a Brazilian airline. A 1-year experience.

    PubMed

    Alves, P M; de Freitas, E J; Mathias, H A; da Motta, A E; Silva, R de C; Müller, M; Almeida, S F; Stapleton, E; Timerman, S; Ramires, J A

    2001-04-01

    After the incorporation of automated external defibrillators by other airlines and the support of the Brazilian Society of Cardiology, Varig Airlines began the onboard defibrillation program with the initial purpose of equipping wide-body aircrafts frequently used in international flights and that airplanes use in the Rio - São Paulo route. With all flight attendants trained, the automated external defibrillation devices were incorporated to 34 airplanes of a total fleet of 80 aircrafts. The devices were installed in the baggage compartments secured with velcro straps and 2 pairs of electrodes, one or which pre-connected to the device to minimize application time. Later, a portable monitor was address to the resuscitation kit in the long flights. The expansion of the knowledge of the basic life support fundamentors and the corrected implantation of the survival chain and of the automated external defibrillators will increase the extense of recovery of cardiorespiratory arrest victims in aircrafts.

  11. What Is an Automated External Defibrillator?

    MedlinePlus

    ANSWERS by heart Treatments + Tests What Is an Automated External Defibrillator? An automated external defibrillator (AED) is a lightweight, portable device ... AED? Non-medical personnel such as police, fire service personnel, flight attendants, security guards and other lay ...

  12. Electrical storm of monomorphic ventricular tachycardia after a cardiac-resynchronization-therapy-defibrillator upgrade.

    PubMed

    Kantharia, Bharat K; Patel, Jigar A; Nagra, Bipinpreet S; Ledley, Gary S

    2006-08-01

    In patients with significant left ventricular dysfunction and congestive heart failure despite optimal medical therapy, implantation of cardiac resynchronization therapy-defibrillation (CRT-D) devices has been shown to improve symptoms and mortality. In this report, we describe a case of a patient with ischaemic cardiomyopathy who developed incessant ventricular tachycardia (VT) after undergoing an upgrade from an implantable cardioverter defibrillator to a CRT-D device. The patient required multiple anti-arrhythmic agents, removal of the coronary sinus lead, and radiofrequency ablation to control VT. Thus, in rare patients, the CRT devices may potentially cause 'proarrhythmia' with serious consequences.

  13. 21 CFR 870.5325 - Defibrillator tester.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Defibrillator tester. 870.5325 Section 870.5325...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Therapeutic Devices § 870.5325 Defibrillator tester. (a) Identification. A defibrillator tester is a device that is connected to the output of...

  14. 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.

  15. Mass transport limitation in implantable defibrillator batteries

    NASA Astrophysics Data System (ADS)

    Schmidt, C.; Tam, G.; Scott, E.; Norton, J.; Chen, K.

    Using cells with lithium reference electrodes, the power-limiting behavior in the lithium-SVO cell was shown to be due to a rapid voltage transition at the anode. A novel test cell was developed to explore the influence of current density, bulk LiAsF 6 concentration, separator type and separator proximity to the anode on the time to onset ( τ) of the anode polarization. The results were found to follow a relationship, iτ1/2∝ Cbulk, consistent with the Sand equation. This relationship also predicts that the critical concentration of LiAsF 6, at which onset of the anode polarization occurs, is near the solubility limit of LiAsF 6 in our system (around 3.5-4.0 M). This general phenomenon was found to be quantitatively similar for two dissimilar separator types, and the anode polarization could also be induced in the absence of separator at high concentration and current density. However, it appears that τ decreases with closer proximity of the separator to the anode surface (i.e. cell stack pressure), suggesting that the effect of separator is to inhibit convective transport to and from the Li surface.

  16. Who Needs an Implantable Cardioverter Defibrillator?

    MedlinePlus

    ... would make one likely) on the following tests. EKG (Electrocardiogram) An EKG is a simple, painless test that detects and ... beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical ...

  17. 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

  18. [Future of implantable electrical cardiac devices].

    PubMed

    Daubert, Jean-Claude; Behaghel, Albin; Leclercq, Christophe; Mabo, Philippe

    2014-03-01

    Major improvements in implantable electrical cardiac devices have been made during the last two decades, notably with the advent of automatic internal defibrillation (ICD) to prevent sudden arrhythmic death, and cardiac resynchronisation (CRT) to treat the discoordinated failing heart. They now constitute a major therapeutic option and may eventually supersede drug therapy. The coming era will be marked by a technological revolution, with improvements in treatment delivery, safety and efficacy, and an expansion of clinical indications. Leadless technologyfor cardiac pacemakers and defibrillators is already in the pipeline, endovascular leads currently being responsible for most long-term complications (lead failure, infection, vein thrombosis, etc.). Miniaturized pacemakers based on nanotechnology can now be totally implanted inside the right ventricle through the transvenous route, thus eliminating leads, pockets and scarring In the same way, totally subcutaneous ICD systems are now available, although they are currently only capable of delivering shocks, without pacing (including antitachycardia pacing). In CRT optimised delivery is important to improve clinical responses and to reduce the non-response rate (around 30 % with current technology). Endocardial left ventricular pacing could be a solution if it can be achieved at an acceptable risk. Multisite ventricular pacing is an alternative. Besides CRT neuromodulation, especially by vagal stimulation, is another important field of device researchfor heart failure. Preliminary clinical results are encouraging. PMID:26427291

  19. Holter ECG for pacemaker/defibrillator carriers: what is its role in the era of remote monitoring?

    PubMed

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

    2015-08-01

    Nowadays several diagnostic tools are available to investigate cardiovascular symptoms like palpitations, dizziness and syncope: ECG Holter (or ambulatory ECG, AECG), external and implantable event/loop recorders. Despite this technological burden, many diagnoses are still missed. In the meantime, we are facing an increasing use of implantable devices for cardiac pacing/defibrillation (CIED), which have rapidly evolved from simple pacing/shock boxes to devices including several diagnostic features. However, these functions are not adequately exploited in current clinical practice and several redundant diagnostic tests, like AECG, are still prescribed to CIED carriers, leading to an increase of costs and a delay in final diagnosis. This review is aimed at identifying the current role of AECG in CIED carriers in view of this technological improvement. First, we will briefly present the indications for AECG according to current guidelines. We will then provide a direct comparison of the different diagnostic features provided by AECG (and event/loop recorders) versus automatic diagnostic CIED to highlight the respective pros and cons. This will serve to carefully discuss these indications in view of the results of recent studies on CIED carriers, highlighting the need for proper implantation and follow-up. Eventually, we will provide useful hints to properly analyse AECG in CIED carriers, considering the different behaviours according to the implemented algorithms. We will conclude by suggesting updated indications for AECG.

  20. A Comparative Survey of Pacemaker Implantation in Trinidad and Tobago in 2005 and 2009

    PubMed Central

    Henry, R; Dookie, T; Primus, E

    2014-01-01

    ABSTRACT Objective: The indications for permanent pacemaker implantations in Trinidad have expanded from initially symptomatic bradycardia to now include complex devices. A retrospective review of the available data was conducted to better understand the evolving trends in device implantation in Trinidad and Tobago. Methods: Data were collated from the two major implanting teams in Trinidad for the years 2005 and 2009. The two implanting centres were the Advanced Cardiovascular Institute (ACI) at Westshore Medical Centre and the Catheterization Laboratory of the Eric Williams Medical Sciences Complex (EWMSC). Data were based on retrospective collation using the implantation records. Results: The implantation rate for new devices increased from 39 per million to 103 per million population. The most common indications for new device implants in 2009 were high degree atrioventricular (AV) block (53%) and sick sinus syndrome (22%), with the notable appearance of congestive cardiomyopathy (13%) which was not present in the earlier cohort. Of particular note, 23 high-end devices were implanted in 2009. These were five cardiac-resynchronization therapy (CRT-P) devices, 14 automatic implantable cardio-defibrillator (AICD) devices and four combined cardiac-resynchronization therapy with defibrillator (CRT-D) devices versus none in 2005. Conclusions: In summary, over the period 2005 to 2009, a substantial increase in device implantation rates has occurred which now include high-end complex devices. Absolute rates, however, remain far below that of developed countries, indicating that the true need remains underserved. Furthermore, adjustment for gross domestic product suggests that the relatively buoyant economy of Trinidad and Tobago is capable of servicing a greater proportion of this need than is currently met. PMID:26108119

  1. 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

  2. Automatic aorta segmentation and valve landmark detection in C-arm CT for transcatheter aortic valve implantation.

    PubMed

    Zheng, Yefeng; John, Matthias; Liao, Rui; Nöttling, Alois; Boese, Jan; Kempfert, Jörg; Walther, Thomas; Brockmann, Gernot; Comaniciu, Dorin

    2012-12-01

    Transcatheter aortic valve implantation (TAVI) is a minimally invasive procedure to treat severe aortic valve stenosis. As an emerging imaging technique, C-arm computed tomography (CT) plays a more and more important role in TAVI on both pre-operative surgical planning (e.g., providing 3-D valve measurements) and intra-operative guidance (e.g., determining a proper C-arm angulation). Automatic aorta segmentation and aortic valve landmark detection in a C-arm CT volume facilitate the seamless integration of C-arm CT into the TAVI workflow and improve the patient care. In this paper, we present a part-based aorta segmentation approach, which can handle structural variation of the aorta in case that the aortic arch and descending aorta are missing in the volume. The whole aorta model is split into four parts: aortic root, ascending aorta, aortic arch, and descending aorta. Discriminative learning is applied to train a detector for each part separately to exploit the rich domain knowledge embedded in an expert-annotated dataset. Eight important aortic valve landmarks (three hinges, three commissures, and two coronary ostia) are also detected automatically with an efficient hierarchical approach. Our approach is robust under all kinds of variations observed in a real clinical setting, including changes in the field-of-view, contrast agent injection, scan timing, and aortic valve regurgitation. Taking about 1.1 s to process a volume, it is also computationally efficient. Under the guidance of the automatically extracted patient-specific aorta model, the physicians can properly determine the C-arm angulation and deploy the prosthetic valve. Promising outcomes have been achieved in real clinical applications. PMID:22955891

  3. Defibrillation safety in emergency helicopter transport.

    PubMed

    Dedrick, D K; Darga, A; Landis, D; Burney, R E

    1989-01-01

    Rotary aircraft play a growing role in the transport of critically ill patients who may require emergency treatment, including defibrillation, during transport. The close quarters and proximity of vital electronic equipment have generated concern among personnel carrying out defibrillation in the air. We address the chief safety issues in helicopter defibrillation by providing measurements of the transient leakage current resulting from contact with a paddle and tested in-flight electronic interference and survey the defibrillation experience of helicopter programs. Our data show that airborne defibrillation is safe. A maximum of 1.5 mA of transient leakage current was measured from a standard battery-powered defibrillator, well within the accepted safety standard of 50 mA. In flight, there was no interference with the avionics or medical equipment, and adequate clearance was available for personnel. Of the helicopter programs surveyed, 69 (87%) had defibrillated in flight without incident. We conclude that defibrillation can be performed in the helicopter without hesitation whether on the ground or in the air, provided standard defibrillation precautions are observed.

  4. 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

  5. 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.

  6. Experimental new automatic tools for robotic stereotactic neurosurgery: towards "no hands" procedure of leads implantation into a brain target.

    PubMed

    Mazzone, P; Arena, P; Cantelli, L; Spampinato, G; Sposato, S; Cozzolino, S; Demarinis, P; Muscato, G

    2016-07-01

    The use of robotics in neurosurgery and, particularly, in stereotactic neurosurgery, is becoming more and more adopted because of the great advantages that it offers. Robotic manipulators easily allow to achieve great precision, reliability, and rapidity in the positioning of surgical instruments or devices in the brain. The aim of this work was to experimentally verify a fully automatic "no hands" surgical procedure. The integration of neuroimaging to data for planning the surgery, followed by application of new specific surgical tools, permitted the realization of a fully automated robotic implantation of leads in brain targets. An anthropomorphic commercial manipulator was utilized. In a preliminary phase, a software to plan surgery was developed, and the surgical tools were tested first during a simulation and then on a skull mock-up. In such a way, several tools were developed and tested, and the basis for an innovative surgical procedure arose. The final experimentation was carried out on anesthetized "large white" pigs. The determination of stereotactic parameters for the correct planning to reach the intended target was performed with the same technique currently employed in human stereotactic neurosurgery, and the robotic system revealed to be reliable and precise in reaching the target. The results of this work strengthen the possibility that a neurosurgeon may be substituted by a machine, and may represent the beginning of a new approach in the current clinical practice. Moreover, this possibility may have a great impact not only on stereotactic functional procedures but also on the entire domain of neurosurgery. PMID:27194228

  7. Experimental new automatic tools for robotic stereotactic neurosurgery: towards "no hands" procedure of leads implantation into a brain target.

    PubMed

    Mazzone, P; Arena, P; Cantelli, L; Spampinato, G; Sposato, S; Cozzolino, S; Demarinis, P; Muscato, G

    2016-07-01

    The use of robotics in neurosurgery and, particularly, in stereotactic neurosurgery, is becoming more and more adopted because of the great advantages that it offers. Robotic manipulators easily allow to achieve great precision, reliability, and rapidity in the positioning of surgical instruments or devices in the brain. The aim of this work was to experimentally verify a fully automatic "no hands" surgical procedure. The integration of neuroimaging to data for planning the surgery, followed by application of new specific surgical tools, permitted the realization of a fully automated robotic implantation of leads in brain targets. An anthropomorphic commercial manipulator was utilized. In a preliminary phase, a software to plan surgery was developed, and the surgical tools were tested first during a simulation and then on a skull mock-up. In such a way, several tools were developed and tested, and the basis for an innovative surgical procedure arose. The final experimentation was carried out on anesthetized "large white" pigs. The determination of stereotactic parameters for the correct planning to reach the intended target was performed with the same technique currently employed in human stereotactic neurosurgery, and the robotic system revealed to be reliable and precise in reaching the target. The results of this work strengthen the possibility that a neurosurgeon may be substituted by a machine, and may represent the beginning of a new approach in the current clinical practice. Moreover, this possibility may have a great impact not only on stereotactic functional procedures but also on the entire domain of neurosurgery.

  8. 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

  9. Effect of a single element subcutaneous array electrode added to a transvenous electrode configuration on the defibrillation field and the defibrillation threshold.

    PubMed

    Kühlkamp, V; Dörnberger, V; Khalighi, K; Mewis, C; Suchalla, R; Ziemer, G; Seipel, L

    1998-12-01

    Even with the use of biphasic shocks, up to 5% of patients need an additional subcutaneous lead to obtain a defibrillation safety margin of at least 10 J. The number of patients requiring additional subcutaneous leads may even increase, because recent generation devices have a < 34 J maximum output in order to decrease their size. In 20 consecutive patients, a single element subcutaneous array lead was implanted in addition to a transvenous lead system consisting of a right ventricular (RV) and a vena cava superior lead using a single infraclavicular incision. The RV lead acted as the cathode; the subcutaneous lead and the lead in the subclavian vein acted as the anode. The biphasic defibrillation threshold was determined using a binary search protocol. Patients were randomized as to whether to start them with the transvenous lead configuration or the combination of the transvenous lead and the subcutaneous lead. In addition, a simplified assessment of the defibrillation field was performed by determining the interelectrode area for the transvenous lead only and the transvenous lead in combination with the subcutaneous lead from a biplane chest X ray. The intraoperative defibrillation threshold was reconfirmed after 1 week, after 3 months, and after 12 months. The mean defibrillation threshold with the additional subcutaneous lead was significantly (P = 0.0001) lower (5.7 +/- 2.9 J) than for the transvenous lead system (9.5 +/- 4.6 J). With the subcutaneous lead, the impedance of the high voltage circuit decreased from 48.9 +/- 7.4 omega to 39.2 +/- 5.0 omega. In the frontal plane, the interelectrode area increased by 11.3% +/- 5.5% (P < 0.0001) and in the lateral plane by 29.5% +/- 12.4% (P < 0.0001). The defibrillation threshold did not increase during follow-up. Complications with the subcutaneous electrode were not observed during a follow-up of 15.8 +/- 2 months. The single finger array lead is useful in order to lower the defibrillation threshold and can be

  10. Pacing and Defibrillators in Complex Congenital Heart Disease

    PubMed Central

    Chubb, Henry; O’Neill, Mark; Rosenthal, Eric

    2016-01-01

    Device therapy in the complex congenital heart disease (CHD) population is a challenging field. There is a myriad of devices available, but none designed specifically for the CHD patient group, and a scarcity of prospective studies to guide best practice. Baseline cardiac anatomy, prior surgical and interventional procedures, existing tachyarrhythmias and the requirement for future intervention all play a substantial role in decision making. For both pacing systems and implantable cardioverter defibrillators, numerous factors impact on the merits of system location (endovascular versus non-endovascular), lead positioning, device selection and device programming. For those with Fontan circulation and following the atrial switch procedure there are also very specific considerations regarding access and potential complications. This review discusses the published guidelines, device indications and the best available evidence for guidance of device implantation in the complex CHD population. PMID:27403295

  11. Safety Of Mris In Patients With Pacemakers And Defibrillators

    PubMed Central

    Baher, Alex; Shah, Dipan

    2013-01-01

    With a burgeoning population, increases in life expectancy, and expanding indications, the number of patients with cardiac devices such as pacemakers and implantable cardioverter defibrillators continues to increase each year. A majority of these patients will develop an indication for magnetic resonance imaging (MRI) in their lifetime. MRIs have established themselves as one of the most powerful imaging tools for a variety of conditions. However, given the historic safety concerns, many physicians are reluctant to use MRIs in this patient population. In this paper, we discuss the potential adverse effects of MRIs in patients with cardiac devices, review key studies that have addressed strategies to limit adverse effects, and provide our cardiovascular MRI laboratory’s protocol for imaging patients with implanted cardiac devices. PMID:24066196

  12. 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.

  13. 75 FR 70015 - External Defibrillators; Public Workshop

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-16

    ... (CDC) to develop a multi-city AED registry that will link with the CDC-funded Cardiac Arrest Registry.... What factors or criteria should be considered when designing external defibrillators for use...

  14. [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.

  15. Impact of expanding indications on the safety of pacemakers and defibrillators.

    PubMed

    Maisel, William H

    2003-01-01

    The number of patients living with a pacemaker or implantable cardioverter defibrillator (ICD) increased markedly during the 1990's. Expanding device indications and increasing device sophistication has important implications for patient and device safety. While the FDA is responsible for assessing the safety and efficacy of medical devices, manufacturers, physicians, patients, medical professional societies, and legislators will all play a role in ensuring that medical device patients continue to receive safe, quality medical care. PMID:12766513

  16. T wave pacing inducing electrical storm and multiple shocks in an ICD-recipient: a novel complication of the automatic gain control function.

    PubMed

    Jaoudé, Simon Abou; Salamé, Elie; Azar, Rabih; Kassab, Roland

    2003-12-01

    Implantable cardioverter-defibrillator (ICD) is highly effective in treating life-threatening ventricular arrhythmias, but it can also have proarrhythmic effect in some cases. We report the case of a 72 years old patient with an ischemic cardiomyopathy in whom an ICD was implanted for a poorly tolerated ventricular tachycardia (Profiles MD-Ventritex). Forty-eight hours after implantation, the patient suddenly received 15 successive shocks. ECG tracings and intracardiac EGM showed the presence of several VT episodes, all induced by the antibradycardia pacing of the ICD: the automatic gain control function of the device failed to detect ventricular premature beats in this patient, leading to a bradycardia pacing falling on the T wave and inducing multiple VTs and shocks.

  17. The Entirely Subcutaneous Defibrillator (S-Icd): State of the Art and Selection of the Ideal Candidate

    PubMed Central

    Maria, Elia De; Olaru, Alina; Cappelli, Stefano

    2015-01-01

    The traditional transvenous defibrillator has been one of the greatest advancement in Cardiology in the last 30 years and has demonstrated to reduce arrhythmic and total mortality in selected patients. However the traditional defibrillator can have a high price to pay in terms of complications, the “weakest link” being the transvenous/endocardial leads. The entirely subcutaneous defibrillator (S-ICD) has recently entered into the clinical scenario and represents a valid alternative to the transvenous device. S-ICD can provide substantial advantages, especially among some subgroups of patients (i.e. after device infection, in young patients and arrhythmogenic syndromes). However, given its characteristics, it is fundamental to choose patients that can benefit the most. In this review we will describe advantages and limitations of the S-ICD and point-out how to select the “ideal candidate” for the implantation. PMID:25158682

  18. 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.

  19. New horizon for infection prevention technology and implantable device.

    PubMed

    Kondo, Yusuke; Ueda, Marehiko; Kobayashi, Yoshio; Schwab, Joerg O

    2016-08-01

    There has been a significant increase in the number of patients receiving cardiovascular implantable electronic devices (CIED) over the last two decades. CIED infection represents a serious complication after CIED implantation and is associated with significant morbidity and mortality. Recently, newly advanced technologies have offered attractive and suitable therapeutic alternatives. Notably, the leadless pacemaker and anti-bacterial envelope decrease the potential risk of CIED infection and the resulting mortality, when it does occur. A completely subcutaneous implantable cardioverter defibrillator is also an alternative to the transvenous implantable cardioverter defibrillator (ICD), as it does not require implantation of any transvenous or epicardial leads. Among the patients who require ICD removal and subsequent antibiotics secondary to infection, the wearable cardioverter defibrillator represents an alternative approach to inpatient monitoring for the prevention of sudden cardiac death. In this review paper, we aimed to introduce the advanced technologies and devices for prevention of CIED infection. PMID:27588153

  20. [Possibilities for cardiac defibrillation using intravascular electrodes].

    PubMed

    Amosov, G G; Tolpekin, V E; Gasanov, E K; Fomichev, D I

    1987-05-01

    The efficiency of electric defibrillation of the heart was assessed in 17 experiments where the position of action electrodes varied. It is suggested that intravascular application of one electrode plus extravascular application of the other gives the optimum effect. The duration of unassisted reversible fibrillation averaged 3 minutes.

  1. An innovative approach to medical control: semiautomatic defibrillators with solid-state memory modules for recording cardiac arrest events.

    PubMed

    Cummins, R O; Austin, D; Graves, J R; Hambly, C

    1988-08-01

    We evaluated the use of microprocessor-based memory modules incorporated into automatic external defibrillators. These solid-state modules store information about each clinical use, including selected segments of the ECG rhythm and notations on defibrillator operation. A playback unit provides annotated printouts of the recorded information. The purpose of our evaluation was to determine whether this memory module could adequately support medical control "run-reviews" when compared with dualfunction (voice and ECG) tape recordings. A total of 41 resuscitation attempts by emergency medical technicians trained to defibrillate (EMT-Ds) were evaluated in five preselected performance areas: defibrillation skills, command and communication at the scene, patient assessment and support, safety, and speed. When performance was reviewed using the tape recordings, the average EMT-D performance score was 16.2 (maximum, 20); when reviewed using the printouts from the medical control modules, the average score, 7.2, was significantly lower (P less than .01). The lower scores with the medical control module occurred because not all five areas of skill could be evaluated adequately by the memory module approach. Assessment of the areas of communication/command at the scene, patient assessment/support, and safety required verbal tape recordings. The medical control module appeared superior to the tape recordings at providing a quick, convenient, and accurate evaluation of rhythm assessment, shock decisions, time intervals, and defibrillator performance. They make several features of medical control review easier and more convenient, and may encourage implementation of early defibrillation programs. We conclude, however, that medical control modules cannot replace on-scene tape recordings for adequate medical control of EMT-D programs. PMID:3394986

  2. 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. PMID:26706454

  3. 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.

  4. 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.

  5. 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.

  6. Availability and use of public access defibrillators in Busan Metropolitan City, South Korea.

    PubMed

    Yoon, Chang Guk; Jeong, Jinwoo; Kwon, In Ho; Lee, Jae Hoon

    2016-01-01

    Out-of-hospital cardiac arrest (OHCA) is considered an important health issue worldwide, and early defibrillation is a key element for a favourable prognosis. In South Korea, public access defibrillation (PAD) programmes were initiated in 2007. However, the impact of PAD programmes on OHCA survival rates remains unclear. This study evaluated the deployment and maintenance status of public automatic external defibrillators (AED), including how frequently they were used, in Busan Metropolitan City, South Korea. Managers of possible AED sites were first contacted by telephone and asked to confirm the possession of an AED. AED suppliers were contacted for AED sales records to identify missing AED sites. AEDs located in ambulances and medical institutions were not included. Investigators visited confirmed AED sites and completed a checklist on AED maintenance and use. In total, 206 AEDs were located, indicative of an AED density of 0.268 AED/km(2) and a prevalence of 6.07 per 100,000 in Busan Metropolitan City. We found that public AEDs had been used for resuscitation only 15 times, an average rate of use of once every 26.3 years. Our results indicate that AEDs in Busan Metropolitan City are underused according to the guidelines, and several are in low-priority locations. We believe that AED deployment based on cardiac arrest statistics is important to optimise layperson AED training and utilisation. PMID:27652097

  7. [A 65-year-old man with wearable cardioverter/defibrillator early after acute myocardial infarction].

    PubMed

    Horlbeck, F W; Nickenig, G; Schwab, J O

    2015-09-01

    A 65-year-old man with severe coronary artery disease and coronary artery bypass graft presented with an acute posterior ST-elevation myocardial infarction. Immediate percutaneous coronary intervention resulted in successful revascularisation of the culprit lesion (RCx) with several remaining coronary stenoses. Despite the reduced left ventricular ejection fraction, no primary prevention indication for an implantable cardioverter/defibrillator early after myocardial infarction existed. Due to the complex coronary anatomy with several remaining stenotic vessels we regarded the patient to be at a particularly high risk for lethal ventricular arrhythmias and provided him with a wearable cardioverter defibrillator (WCD). Twenty-six days later, he experienced spontaneous ventricular tachycardia and fibrillation which was successfully treated with high voltage therapy by the WCD. Subsequently, we decided to implant him an ICD following secondary prevention indication. Besides established indications for primary prevention ICD therapy, some patients early after myocardial infarction may be at a particularly high risk for sudden cardiac death. Temporary protection with a WCD in carefully selected patients can offer a safe opportunity for later reevaluation of permanent ICD implantation depending on the course of left ventricular ejection fraction and the occurrence of arrhythmia. PMID:26338064

  8. Myocardial ischemic hyperacute T-wave oversensing leading to a defibrillator shock storm

    PubMed Central

    Khalid, Nauman; Kluger, Jeffrey

    2015-01-01

    Appropriate sensing is essential for the normal functioning of an implantable cardioverter defibrillator (ICD). T-wave oversensing is a potential clinical problem in ICD patients that may result in inappropriate shocks. Oversensing may have various underlying causes and can be treated with noninvasive or invasive means. We present the case of a 45-year-old man presenting with shock storm as a result of T-wave oversensing. Workup revealed a hemodynamically significant stenosis of the left anterior descending artery treated with percutaneous coronary intervention and drug-eluting stent placement. This resulted in the resolution of T-wave missensing and restoration of normal ICD functioning. PMID:25829654

  9. Evaluation and automatic correction of metal-implant-induced artifacts in MR-based attenuation correction in whole-body PET/MR imaging.

    PubMed

    Schramm, G; Maus, J; Hofheinz, F; Petr, J; Lougovski, A; Beuthien-Baumann, B; Platzek, I; van den Hoff, J

    2014-06-01

    The aim of this paper is to describe a new automatic method for compensation of metal-implant-induced segmentation errors in MR-based attenuation maps (MRMaps) and to evaluate the quantitative influence of those artifacts on the reconstructed PET activity concentration. The developed method uses a PET-based delineation of the patient contour to compensate metal-implant-caused signal voids in the MR scan that is segmented for PET attenuation correction. PET emission data of 13 patients with metal implants examined in a Philips Ingenuity PET/MR were reconstructed with the vendor-provided method for attenuation correction (MRMap(orig), PET(orig)) and additionally with a method for attenuation correction (MRMap(cor), PET(cor)) developed by our group. MRMaps produced by both methods were visually inspected for segmentation errors. The segmentation errors in MRMap(orig) were classified into four classes (L1 and L2 artifacts inside the lung and B1 and B2 artifacts inside the remaining body depending on the assigned attenuation coefficients). The average relative SUV differences (ε(rel)(av)) between PET(orig) and PET(cor) of all regions showing wrong attenuation coefficients in MRMap(orig) were calculated. Additionally, relative SUV(mean) differences (ε(rel)) of tracer accumulations in hot focal structures inside or in the vicinity of these regions were evaluated. MRMap(orig) showed erroneous attenuation coefficients inside the regions affected by metal artifacts and inside the patients' lung in all 13 cases. In MRMap(cor), all regions with metal artifacts, except for the sternum, were filled with the soft-tissue attenuation coefficient and the lung was correctly segmented in all patients. MRMap(cor) only showed small residual segmentation errors in eight patients. ε(rel)(av) (mean ± standard deviation) were: (-56 ± 3)% for B1, (-43 ± 4)% for B2, (21 ± 18)% for L1, (120 ± 47)% for L2 regions. ε(rel) (mean ± standard deviation) of hot focal structures were: (-52

  10. Public access defibrillation: a shocking idea?

    PubMed

    Woollard, M

    2001-06-01

    Currently, survival from out-of-hospital cardiac arrest in the United Kingdom is poor. Ambulance response standards require that an ambulance reach 75 per cent of cardiac arrests within 8 min. But a short time to defibrillation from the onset of collapse is a key predictor of outcome from out-of-hospital cardiac arrest. The Department of Health has recently implemented a lay responder defibrillation programme, with the aim of shortening this time interval for victims in public places. This initiative utilizes automated external defibrillators (AEDs), which provide written and recorded voice prompts to minimize training requirements and errors in use. Lay responder AED programmes with very short response times have reported survival to discharge rates of up to 53 per cent for patients presenting in ventricular fibrillation (VF). This compares well with the results of a meta-analysis that reported a survival rate of only 6.4 per cent for traditional defibrillator-equipped ambulance systems. The annual incidence of out-of-hospital cardiac arrest in England is 123 per 100,000 population. Approximately half of these present in VF, and could benefit from an AED programme. But only 16 per cent of cardiac arrests occur in a public place. It has been calculated that there are approximately 5,000 instances of VF in public places each year in England. If half of these patients can be reached and administered a first shock within 4 min of their collapse, an additional 400 victims may survive each year. Given the current investment by the DoH of 2 million pounds, this suggests a cost per life saved of approximately 505 pounds over a 10 year period. PMID:11450941

  11. TED-Time and life saving External Defibrillator for home-use.

    PubMed

    Weiss, Teddy A; Rosenheck, Shimon; Gorni, Shraga; Katz, Ioni; Mendelbaum, Mendel; Gilon, Dan

    2014-06-01

    Sudden Cardiac Death--SCD --is a major unmet health problem that needs urgent and prompt solution. AICDs are very expensive, risky and indicated for a small group of patients, at the highest risk. AEDs--Automatic External Defibrillators--are designed for public places and although safe, cannot enter the home-market due to their cost and need for constant, high-cost maintenance. We developed TED, a low-cost AED that derives its energy off the mains, designed for home-use, to save SCD victims' lives. PMID:24721586

  12. TED-Time and life saving External Defibrillator for home-use.

    PubMed

    Weiss, Teddy A; Rosenheck, Shimon; Gorni, Shraga; Katz, Ioni; Mendelbaum, Mendel; Gilon, Dan

    2014-06-01

    Sudden Cardiac Death--SCD --is a major unmet health problem that needs urgent and prompt solution. AICDs are very expensive, risky and indicated for a small group of patients, at the highest risk. AEDs--Automatic External Defibrillators--are designed for public places and although safe, cannot enter the home-market due to their cost and need for constant, high-cost maintenance. We developed TED, a low-cost AED that derives its energy off the mains, designed for home-use, to save SCD victims' lives.

  13. Sexual Health for Patients with an Implantable Cardioverter Defibrillator

    MedlinePlus

    ... LIBRARY Hello, Guest! My alerts Sign In Join Facebook Twitter Home About this Journal Editorial Board General Statistics Circulation Cover Doodle → Blip the Doodle Go Red For Women's Issue Information for Advertisers Author Reprints Commercial Reprints Customer Service and Ordering ...

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

    MedlinePlus

    ... M.D.; Barry J. Maron, M.D.; Frank Marcus, M.D.; Melvin Scheinman, M.D.; Bruce L. ... primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and ...

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

    MedlinePlus

    ... American Heart Association Facebook Twitter Hello, Guest! My alerts Sign In Join Institution: NATIONAL INST HEALTH LIBRARY ... Institution: NATIONAL INST HEALTH LIBRARY Hello, Guest! My alerts Sign In Join Facebook Twitter Home About this ...

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

    MedlinePlus

    ... High-tension wires Metal detectors Industrial welders Electrical generators These devices can disrupt the electrical signaling of ... 2 feet away from industrial welders or electrical generators. Rarely, ICDs have caused unnecessary shocks during long, ...

  17. 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.

  18. 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. PMID:12394622

  19. Double Sequential Defibrillation for Refractory Ventricular Fibrillation: A Case Report.

    PubMed

    Lybeck, Aurora M; Moy, Hawnwan Philip; Tan, David K

    2015-01-01

    A 40-year-old male struck his chest against a pole during a basketball game and had sudden out-of-hospital cardiac arrest. After bystander cardiopulmonary resuscitation, fire and emergency medical services personnel provided six defibrillation attempts prior to emergency department arrival. A 7th attempt in the emergency department using a different vector was unsuccessful. On the 8th attempt, using a second defibrillator with defibrillator pads placed adjacent to the primary set of defibrillator pads, two shocks were administered in near simultaneous fashion. The double sequential defibrillation was successful and the patient had return of spontaneous circulation at the next pulse check. He recovered in the intensive care unit, was discharged home 1 month later, and continues to follow up in clinic over 1 year later with a Cerebral Performance Category score of 1 (short-term memory deficits).

  20. Numerical analysis of electrical defibrillation. The parallel approach.

    PubMed

    Ng, K T; Hutchinson, S A; Gao, S

    1995-01-01

    Numerical modeling offers a viable tool for studying electrical defibrillation, allowing the behavior of field quantities to be observed easily as the different system parameters are varied. One numerical technique, namely the finite-element method, has been found particularly effective for modeling complex thoracic anatomies. However, an accurate finite-element model of the thorax often requires a large number of elements and nodes, leading to a large set of equations that cannot be solved effectively with the computational power of conventional computers. This is especially true if many finite-element solutions need to be achieved within a reasonable time period (eg, electrode configuration optimization). In this study, the use of massively parallel computers to provide the memory and reduction in solution time for solving these large finite-element problems is discussed. Both the uniform and unstructured grid approaches are considered. Algorithms that allow efficient mapping of uniform and unstructured grids to data-parallel and message-passing parallel computers are discussed. An automatic iterative procedure for electrode configuration optimization is presented. The procedure is based on the minimization of an objective function using the parallel direct search technique. Computational performance results are presented together with simulation results. PMID:8656104

  1. [ILCOR recommendation on signage of automated external defibrillators (AEDs)].

    PubMed

    Truhlár, A

    2010-05-01

    Early defibrillation is a determinant of survival in both out-of-hospital and in-hospital cardiac arrests from ventricular fibrillation and pulseless ventricular tachycardia. The review summarizes importance of early defibrillation with automated external defibrillators (AED) and presents the International Liaison Committee on Resuscitation (ILCOR) recommendation for universal AED sign. The aim of the recommendation is to unify the AED signs worldwide and to spread the knowledge of this. The public in general, but healthcare professionals particularly, should be able to recognize AED location and use the device immediately in case of cardiac arrest.

  2. 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. PMID:9227756

  3. 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...

  4. 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...

  5. 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

  6. Experience of cardioverter-defibrillators inserted without thoracotomy: evaluation of transvenously inserted intracardiac leads alone or with a subcutaneous axillary patch.

    PubMed Central

    Jordaens, L; Trouerbach, J W; Vertongen, P; Herregods, L; Poelaert, J; Van Nooten, G

    1993-01-01

    OBJECTIVES--To compare the efficacy of a purely transvenous cardioverter-defibrillator (ICD) system with that of a system with a supplementary subcutaneous patch. To evaluate clinical follow up of these lead arrangements that do not require thoracotomy. DESIGN--A simplified defibrillation protocol to test two different lead arrangements during implantation, with routine clinical follow up after implantation. SETTING--Tertiary referral centre for treatment of arrhythmia. PATIENTS--22 consecutive patients selected for implantation of an ICD because of life-threatening ventricular arrhythmias (ventricular fibrillation or sustained ventricular tachycardia) of whom 20 entered the test protocol. INTERVENTION--Implantation of an ICD with transvenously inserted intracardiac leads and a subcutaneous patch and assessment of effective defibrillation followed by testing of the purely transvenous approach. MAIN OUTCOME MEASURES--Reproducible conversion of ventricular fibrillation to sinus rhythm at a certain energy level, providing a safety margin of at least 10 J for both lead arrangements. Confirmation of efficacy during clinical follow up (mean 6 months). RESULTS--A transvenous lead system combined with a subcutaneous axillary patch was implanted in 20/22 patients and it provided adequate and acceptable energy levels. In 10/20 tested patients a purely transvenous lead configuration provided an acceptable safety margin as well. Nine patients had clinical recurrences: all these arrhythmias were successfully converted. CONCLUSION--A transvenous lead system was sufficient in 50% of the patients at the time of implantation. Data on long-term clinical follow up of this arrangement are not available. The approach without thoracotomy with a subcutaneous patch is feasible and effective in most patients selected for ICD treatment. Images PMID:8457387

  7. Electrical storm after CRT implantation treated by AV delay optimization.

    PubMed

    Combes, Nicolas; Marijon, Eloi; Boveda, Serge; Albenque, Jean-Paul

    2010-02-01

    We present a case of symptomatic ischemic heart failure with an indication for cardiac resynchronization and implantable cardiac defibrillator therapy in primary prevention. After implantation, the patient developed a severe electrical storm with multiple shocks. Hemodynamic improvement based only on AV delay, guided by echocardiography and ECG, brought about a dramatic improvement in the situation. We discuss the pathophysiology of electrical storm occurring immediately after LV pacing.

  8. [Implantation of a biventricular ICD in a patient with dextrocardia with situs inversus].

    PubMed

    Vurgun, Veysel Kutay; Gerede, Menekşe; Altın, Ali Timuçin; Candemir, Başar; Akyürek, Ömer

    2015-01-01

    In order to reduce sudden cardiac death and heart failure symptoms, biventricular implantable cardioverter defibrillator (ICD) implantation is a treatment method commonly used in selected patients with cardiomyopathy. The frequency of dextrocardia in congenital heart defects is approximately 0.4/10000. In this group, the frequency of cardiomyopathy development is rare. In this case report we present a patient with dextrocardia undergoing implantation of biventricular ICD.

  9. Adhoc electromagnetic compatibility testing of non-implantable medical devices and radio frequency identification

    PubMed Central

    2013-01-01

    Background The use of radiofrequency identification (RFID) in healthcare is increasing and concerns for electromagnetic compatibility (EMC) pose one of the biggest obstacles for widespread adoption. Numerous studies have documented that RFID can interfere with medical devices. The majority of past studies have concentrated on implantable medical devices such as implantable pacemakers and implantable cardioverter defibrillators (ICDs). This study examined EMC between RFID systems and non-implantable medical devices. Methods Medical devices were exposed to 19 different RFID readers and one RFID active tag. The RFID systems used covered 5 different frequency bands: 125–134 kHz (low frequency (LF)); 13.56 MHz (high frequency (HF)); 433 MHz; 915 MHz (ultra high frequency (UHF])) and 2.4 GHz. We tested three syringe pumps, three infusion pumps, four automatic external defibrillators (AEDs), and one ventilator. The testing procedure is modified from American National Standards Institute (ANSI) C63.18, Recommended Practice for an On-Site, Ad Hoc Test Method for Estimating Radiated Electromagnetic Immunity of Medical Devices to Specific Radio-Frequency Transmitters. Results For syringe pumps, we observed electromagnetic interference (EMI) during 13 of 60 experiments (22%) at a maximum distance of 59 cm. For infusion pumps, we observed EMI during 10 of 60 experiments (17%) at a maximum distance of 136 cm. For AEDs, we observed EMI during 18 of 75 experiments (24%) at a maximum distance of 51 cm. The majority of the EMI observed was classified as probably clinically significant or left the device inoperable. No EMI was observed for all medical devices tested during exposure to 433 MHz (two readers, one active tag) or 2.4 GHz RFID (two readers). Conclusion Testing confirms that RFID has the ability to interfere with critical medical equipment. Hospital staff should be aware of the potential for medical device EMI caused by RFID systems and should be encouraged to

  10. 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.

  11. How does an electric field defibrillate cardiac muscle?

    NASA Astrophysics Data System (ADS)

    Pumir, Alain; Krinsky, Valentin I.

    Cardiac fibrillation is caused by an irregular wave propagation. Fibrillation can be eliminated by a strong electric field (5 kV, 20 A, 2 msec). The mechanism of this phenomenon (defibrillation) is not known. The principal difficulty, as shown in experiments and confirmed by classical cable theory, is that the changes in transmembrane potential, e, induced by electric field, decay exponentially with distance from the electrodes. We study wave suppression by an electric field in generic excitable media. In excitable media consisting of separate cells (similar to biological tissues), we have found a suppression of rotating waves and defibrillation induced by strong electric field, contrary to what happens in continuous media. We show that the spatially periodic component of e which arises in cellular media is responsible for defibrillation. We have found that (i) it does not decay with distance; (ii) it can excite quiescent cells and terminate excitation in excited cells; (iii) the coupling between cardiac cells is a crucial parameter affecting the amplitude of the spatially periodic component of e, and the efficiency of defibrillation. New experiments on cardiac muscle are proposed.

  12. 21 CFR 870.5310 - Automated external defibrillator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Automated external defibrillator. 870.5310 Section 870.5310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Therapeutic Devices § 870.5310...

  13. ICD Shock, Not Ventricular Fibrillation, Causes Elevation of High Sensitive Troponin T after Defibrillation Threshold Testing—The Prospective, Randomized, Multicentre TropShock-Trial

    PubMed Central

    Semmler, Verena; Biermann, Jürgen; Haller, Bernhard; Jilek, Clemens; Sarafoff, Nikolaus; Lennerz, Carsten; Vrazic, Hrvoje; Zrenner, Bernhard; Asbach, Stefan; Kolb, Christof

    2015-01-01

    Background The placement of an implantable cardioverter defibrillator (ICD) has become routine practice to protect high risk patients from sudden cardiac death. However, implantation-related myocardial micro-damage and its relation to different implantation strategies are poorly characterized. Methods A total of 194 ICD recipients (64±12 years, 83% male, 95% primary prevention of sudden cardiac death, 35% cardiac resynchronization therapy) were randomly assigned to one of three implantation strategies: (1) ICD implantation without any defibrillation threshold (DFT) testing, (2) estimation of the DFT without arrhythmia induction (modified “upper limit of vulnerability (ULV) testing”) or (3) traditional safety margin testing including ventricular arrhythmia induction. High-sensitive Troponin T (hsTnT) levels were determined prior to the implantation and 6 hours after. Results All three groups showed a postoperative increase of hsTnT. The mean delta was 0.031±0.032 ng/ml for patients without DFT testing, 0.080±0.067 ng/ml for the modified ULV-testing and 0.064±0.056 ng/ml for patients with traditional safety margin testing. Delta hsTnT was significantly larger in both of the groups with intraoperative ICD testing compared to the non-testing strategy (p≤0.001 each). There was no statistical difference in delta hsTnT between the two groups with intraoperative ICD testing (p = 0.179). Conclusion High-sensitive Troponin T release during ICD implantation is significantly higher in patients with intraoperative ICD testing using shock applications compared to those without testing. Shock applications, with or without arrhythmia induction, did not result in a significantly different delta hsTnT. Hence, the ICD shock itself and not ventricular fibrillation seems to cause myocardial micro-damage. Trial Registration ClinicalTrials.gov NCT01230086 PMID:26208329

  14. Defibrillation lead placement using a transthoracic transatrial approach in a case without transvenous access due to lack of the right superior vena cava.

    PubMed

    Otsuka, Yosuke; Okamura, Hideo; Sato, Syunsuke; Nakajima, Ikutaro; Ishibashi, Kohei; Miyamoto, Kouji; Noda, Takashi; Aiba, Takeshi; Kamakura, Shiro; Kobayashi, Junjiro; Yasuda, Satoshi; Ogawa, Hisao; Kusano, Kengo

    2015-06-01

    A 65-year-old woman with a history of syncope was diagnosed with hypertrophic cardiomyopathy. She had previously undergone mastectomy of the left breast owing to breast cancer. Holter electrocardiogram (ECG) and monitor ECG revealed sick sinus syndrome (Type II) and non-sustained ventricular tachycardia. Sustained ventricular tachycardia and ventricular fibrillation were induced in an electrophysiological study. Although the patient was eligible for treatment with a dual chamber implantable cardioverter defibrillator (ICD), venography revealed lack of the right superior vena cava (R-SVC). Lead placement from the left subclavian vein would have increased the risk of lymphedema owing to the patient׳s mastectomy history. Consequently, the defibrillation lead was placed in the right ventricle by direct puncture of the right auricle through the tricuspid valve. The atrial lead was sutured to the atrial wall, and the postoperative course was unremarkable. Defibrillation lead placement using a transthoracic transatrial approach can be an alternative method in cases where a transvenous approach for lead placement is not feasible.

  15. Implant healing in experimental animal models of diabetes.

    PubMed

    Le, Nga N; Rose, Michael B; Levinson, Howard; Klitzman, Bruce

    2011-05-01

    Diabetes mellitus is becoming increasingly prevalent worldwide. Additionally, there is an increasing number of patients receiving implantable devices such as glucose sensors and orthopedic implants. Thus, it is likely that the number of diabetic patients receiving these devices will also increase. Even though implantable medical devices are considered biocompatible by the Food and Drug Administration, the adverse tissue healing that occurs adjacent to these foreign objects is a leading cause of their failure. This foreign body response leads to fibrosis, encapsulation of the device, and a reduction or cessation of device performance. A second adverse event is microbial infection of implanted devices, which can lead to persistent local and systemic infections and also exacerbates the fibrotic response. Nearly half of all nosocomial infections are associated with the presence of an indwelling medical device. Events associated with both the foreign body response and implant infection can necessitate device removal and may lead to amputation, which is associated with significant morbidity and cost. Diabetes mellitus is generally indicated as a risk factor for the infection of a variety of implants such as prosthetic joints, pacemakers, implantable cardioverter defibrillators, penile implants, and urinary catheters. Implant infection rates in diabetic patients vary depending upon the implant and the microorganism, however, for example, diabetes was found to be a significant variable associated with a nearly 7.2% infection rate for implantable cardioverter defibrillators by the microorganism Candida albicans. While research has elucidated many of the altered mechanisms of diabetic cutaneous wound healing, the internal healing adjacent to indwelling medical devices in a diabetic model has rarely been studied. Understanding this healing process is crucial to facilitating improved device design. The purpose of this article is to summarize the physiologic factors that

  16. 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.

  17. Transthoracic defibrillation: effect of sternotomy on chest impedance.

    PubMed

    Kerber, R E; Vance, S; Schomer, S J; Mariano, D J; Charbonnier, F

    1992-07-01

    The purpose of this study was to determine the effect of sternotomy on transthoracic impedance, a major determinant of current flow and defibrillation success. Transthoracic impedance was determined by using a validated test-pulse technique that does not require actual shocks. Seventeen patients undergoing median sternotomy were studied prospectively. Transthoracic impedance was determined before operation, 3 to 5 days after operation and (in eight patients) greater than or equal to 1 month after operation. When measured using paddle electrodes placed in the standard apex-right parasternal defibrillating position, transthoracic impedance declined after sternotomy in all patients, from 77 +/- 18 to 59 +/- 17 omega (p less than 0.01); smaller declines were demonstrated by using other electrode positions. Transthoracic impedance remained below the preoperative level in the eight patients who underwent a second set of measurements at least 1 month after operation. Six normal subjects not undergoing sternotomy underwent serial transthoracic impedance measurements at least 5 days apart; mean transthoracic impedance did not change. It is concluded that transthoracic impedance declines after sternotomy. At any operator-selected energy level a higher current flow will result after sternotomy; this may facilitate postoperative defibrillation.

  18. Skeletal muscle grids for assessing current distributions from defibrillation shocks.

    PubMed

    Schmidt, J; Gatlin, B; Eason, J; Koomullil, G; Pilkington, T

    1992-01-01

    This paper utilizes a structured and an unstructured grid representation of a torso with an anisotropic skeletal muscle to assess current distributions from defibrillation shocks. The results show that a finite-element solution on an unstructured grid of 400,000 elements (60,000 nodes) achieves comparable current distributions with a finite-difference solution on a structured grid that uses approximately the same number of nodes. Moreover, a finite-element solution on a 65,000-element (10,500 nodes) unstructured grid yielded fractional percent current results within 5% of the finer grids. The structured and unstructured grid models are used to investigate recent interpretations of experimental data that concluded that more than 80% of the total defibrillation current is shunted by the anisotropic skeletal muscle thoracic cage. It is concluded that these interpretations, which were based on a one-dimensional resistive network representation of the three-dimensional defibrillation situation, overestimate by 25% the current shunted by the anisotropic thoracic cage. PMID:1424684

  19. 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

  20. Potential value of automated daily screening of cardiac resynchronization therapy defibrillator diagnostics for prediction of major cardiovascular events: results from Home-CARE (Home Monitoring in Cardiac Resynchronization Therapy) study

    PubMed Central

    Sack, Stefan; Wende, Christian Michael; Nägele, Herbert; Katz, Amos; Bauer, Wolfgang Rudolf; Barr, Craig Scott; Malinowski, Klaus; Schwacke, Harald; Leyva, Francisco; Proff, Jochen; Berdyshev, Sergey; Paul, Vincent

    2011-01-01

    Aim To investigate whether diagnostic data from implanted cardiac resynchronization therapy defibrillators (CRT-Ds) retrieved automatically at 24 h intervals via a Home Monitoring function can enable dynamic prediction of cardiovascular hospitalization and death. Methods and results Three hundred and seventy-seven heart failure patients received CRT-Ds with Home Monitoring option. Data on all deaths and hospitalizations due to cardiovascular reasons and Home Monitoring data were collected prospectively during 1-year follow-up to develop a predictive algorithm with a predefined specificity of 99.5%. Seven parameters were included in the algorithm: mean heart rate over 24 h, heart rate at rest, patient activity, frequency of ventricular extrasystoles, atrial–atrial intervals (heart rate variability), right ventricular pacing impedance, and painless shock impedance. The algorithm was developed using a 25-day monitoring window ending 3 days before hospitalization or death. While the retrospective sensitivities of the individual parameters ranged from 23.6 to 50.0%, the combination of all parameters was 65.4% sensitive in detecting cardiovascular hospitalizations and deaths with 99.5% specificity (corresponding to 1.83 false-positive detections per patient-year of follow-up). The estimated relative risk of an event was 7.15-fold higher after a positive predictor finding than after a negative predictor finding. Conclusion We developed an automated algorithm for dynamic prediction of cardiovascular events in patients treated with CRT-D devices capable of daily transmission of their diagnostic data via Home Monitoring. This tool may increase patients’ quality of life and reduce morbidity, mortality, and health economic burden, it now warrants prospective studies. ClinicalTrials.gov  NCT00376116. PMID:21852311

  1. Successful defibrillation in profound hypothermia (core body temperature 25.6 degrees C).

    PubMed

    Thomas, R; Cahill, C J

    2000-11-01

    We report a case of successful defibrillation in a severely hypothermic patient with a core body temperature of 25.6 degrees C as measured oesophageally. Ventricular fibrillation is a recognised life threatening arrhythmia in severely hypothermic patients. The traditional wisdom is that this arrhythmia is refractory to defibrillation at temperatures below 28 degrees C. PMID:11114463

  2. 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.

  3. 78 FR 17890 - Effective Date of Requirement for Premarket Approval for Automated External Defibrillator System.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-25

    ... Approval for Automated External Defibrillator System. AGENCY: Food and Drug Administration, HHS. ACTION... the following class III preamendments devices: Automated external defibrillators systems (AEDs), which... Innovation Act (FDASIA) (Pub. L. 112-144) establish a comprehensive system for the regulation of...

  4. 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"…

  5. 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…

  6. Potential impact of public access defibrillators on survival after out of hospital cardiopulmonary arrest: retrospective cohort study

    PubMed Central

    Pell, Jill P; Sirel, Jane M; Marsden, Andrew K; Ford, Ian; Walker, Nicola L; Cobbe, Stuart M

    2002-01-01

    Objective To estimate the potential impact of public access defibrillators on overall survival after out of hospital cardiac arrest. Design Retrospective cohort study using data from an electronic register. A statistical model was used to estimate the effect on survival of placing public access defibrillators at suitable or possibly suitable sites. Setting Scottish Ambulance Service. Subjects Records of all out of hospital cardiac arrests due to heart disease in Scotland in 1991-8. Main outcome measures Observed and predicted survival to discharge from hospital. Results Of 15 189 arrests, 12 004 (79.0%) occurred in sites not suitable for the location of public access defibrillators, 453 (3.0%) in sites where they may be suitable, and 2732 (18.0%) in suitable sites. Defibrillation was given in 67.9% of arrests that occurred in possibly suitable sites for locating defibrillators and in 72.9% of arrests that occurred in suitable sites. Compared with an actual overall survival of 744 (5.0%), the predicted survival with public access defibrillators ranged from 942 (6.3%) to 959 (6.5%), depending on the assumptions made regarding defibrillator coverage. Conclusions The predicted increase in survival from targeted provision of public access defibrillators is less than the increase achievable through expansion of first responder defibrillation to non-ambulance personnel, such as police or firefighters, or of bystander cardiopulmonary resuscitation. Additional resources for wide scale coverage of public access defibrillators are probably not justified by the marginal improvement in survival. What is already known on this topicThree quarters of all deaths from acute coronary events occur before the patient reaches a hospitalDefibrillation is an independent predictor of survival from out of hospital cardiac arrestThe probability of a rhythm being amenable to defibrillation declines with timeInterest in providing public access defibrillators to reduce the time to

  7. Dental Implants

    MedlinePlus

    ... Procedures Dental Implants Dentures Direct Bonding Implants versus Bridges Orthodontics and Aligners Periodontal Plastic Surgery Porcelain Crowns Porcelain Fixed Bridges Porcelain Veneers Repairing Chipped Teeth Teeth Whitening Tooth- ...

  8. Defibrillation via the elimination of spiral turbulence in a model for ventricular fibrillation.

    PubMed

    Sinha, S; Pande, A; Pandit, R

    2001-04-16

    Ventricular fibrillation, the major reason behind sudden cardiac death, is turbulent cardiac electrical activity in which rapid, irregular disturbances in the spatiotemporal electrical activation of the heart make it incapable of any concerted pumping action. Methods of controlling ventricular fibrillation include electrical defibrillation as well as injected medication. Electrical defibrillation, though widely used, involves subjecting the whole heart to massive, and often counterproductive, electrical shocks. We propose a defibrillation method that uses a very low-amplitude shock (of order mV) applied for a brief duration (of order 100 ms) and over a coarse mesh of lines on our model ventricle.

  9. The DATAS rationale and design: a controlled, randomized trial to assess the clinical benefit of dual chamber (DDED) defibrillator.

    PubMed

    Quesada, Aurelio; Almendral, Jesús; Arribas, Fernando; Ricci, Renato; Wolpert, Christian; Adragao, Pedro; Cobo, Eric; Navarro, Xavier

    2004-03-01

    Single chamber (SC) implantable cardioverter defibrillators (ICDs) have several limitations that might be relevant during follow-up, like atrial pacing requirements, inadequate therapies, sustained atrial tachyarrhythmias and difficulties to achieve an accurate diagnosis of the arrhythmia. Dual chamber (DC) ICDs offer an attractive and rational solution, although controversy remains if the costs and complexity of these devices offer a real clinical advantage. The Dual Chamber & Atrial Tachyarrhythmias Adverse Events Study (DATAS) was designed to analyze the ability of DC ICD, DDED, to reduce clinically significant adverse events compared with SC ICD in a non-selected population with conventional indications for ICD implantation. This is a prospective, multicentre, randomized, open labelled study, with three arms: two of them (simulated SC ICD and true DC ICD) cross-over, and the third (true SC ICD) parallels the other two. The composite primary end point comprises four Clinically Significant Adverse Events (CSAE): (1) all-cause mortality, (2) invasive intervention, hospitalization or prolongation of hospitalization due to cardiovascular cause, (3) inappropriate shocks, and (4) sustained symptomatic atrial tachyarrhythmias that (a) require urgent termination or (b) last more than 48h leading to therapeutic intervention. Secondary end points constitute each of the individual components of CSAE, cardiovascular status, quality of life and a detailed analysis of atrial and ventricular arrhythmias. To date (June 2003) there have been 343 patients enroled from 947 screened patients. The projected enrollment includes 360 patients and the conclusion of the study is expected at the beginning of 2005.

  10. Rationale and design of WEBCARE: A randomized, controlled, web-based behavioral intervention trial in cardioverter-defibrillator patients to reduce anxiety and device concerns and enhance quality of life

    PubMed Central

    2009-01-01

    Background The implantable cardioverter defibrillator (ICD) is generally well accepted, but 25-33% of patients experience clinical levels of anxiety, depression, and impaired quality of life (QoL) following implantation. Few trials in ICD patients have investigated whether behavioral intervention may mitigate the development of these adjustment problems. We present the rationale and study design of the WEB-based distress management program for implantable CARdioverter dEfibrillator patients (WEBCARE) trial. Methods WEBCARE is a multi-center, multi-disciplinary, randomized, controlled behavioral intervention trial designed to examine the effectiveness of a web-based approach in terms of reducing levels of anxiety and device concerns and enhancing QoL. Consecutive patients hospitalized for the implantation of an ICD will be approached for study participation while in hospital and randomized to the intervention arm (n = 175) versus usual care (n = 175) at baseline (5-10 days post implantation). Patients will complete assessments of patient-centered outcomes at baseline, 14, 26, and 52 weeks after implantation. Patients randomized to the intervention arm will receive a 12-week web-based behavioral intervention starting 2 weeks after implantation. Primary endpoints include (ii) patient-centered outcomes (i.e., anxiety, depression, ICD acceptance, QoL); (iii) health care utilization; and (iiii) cost-effectiveness. All primary endpoints will be assessed with standardized and validated disease-specific or generic questionnaires. Secondary endpoints include (iii) cortisol awakening response; and (iiii) ventricular arrhythmias. Discussion WEBCARE will show whether a behavioral intervention using a web-based approach is feasible and effective in reducing anxiety and ICD concerns and improving QoL in ICD patients. Trial Registration http://www.ClinicalTrials.gov. Identifier: NCT00895700. PMID:20030843

  11. Development of standard test methods for evaluating defibrillation recovery characteristics of disposable ECG electrodes.

    PubMed

    Schoenberg, A A; Booth, H E; Lyon, P C

    1979-01-01

    A clinically relevant test for the measurement of defibrillation overload recovery of prefilled disposable ECG electrodes was developed and is proposed for use in an ECG electrode standard under development by AAMI. Defibrillation overload voltages and currents, as well as electrode polarization recovery voltages, were first measured in animal tests on 12 types of electrodes to allow correlation with various bench tests using a capacitor discharge at 10, 200, or 1000 V. Current overloads absorbed by the electrodes under worst conditions in animal tests were in the range of 2 percent of the defibrillation current flowing through the chest. These overloads were absorbed by most Ag-AgCl electrodes without excessive polarization. However, stainless steel, brass, and tin electrodes tended to polarize to levels that would saturate many ECG monitors. A standard bench test using a 200-V 10-muF capacitor was recommended for inclusion in the AAMI standard to determine whether electrodes are acceptable for use during defibrillation.

  12. Defibrillator electrode-chest wall coupling agents: influence on transthoracic impedance and shock success.

    PubMed

    Aylward, P E; Kieso, R; Hite, P; Charbonnier, F; Kerber, R E

    1985-09-01

    The purpose of this study was to determine if the difference in transthoracic impedance produced by different coupling agents affects the success of shocks for defibrillation. Three different coupling agents, Harco pads (Hewlett-Packard), Littman pads (3M) and Redux paste (Hewlett-Packard), were assessed in 10 anesthetized dogs in which ventricular fibrillation was induced by electrical stimulation of the right ventricle. Defibrillation was attempted 15 seconds later, using 50, 100 and 150 joules (selected energy). Actual delivered energy, current, impedance and the percent of the shocks that achieved defibrillation were determined for the three coupling agents. Redux paste gave significantly lower impedance and higher current than the two disposable performed coupling pads tested. Despite this, there were no significant differences in shock success among the three coupling agents. Thus, in this experimental model, over a three-fold energy range, disposable coupling pads were as effective as electrode paste for defibrillation despite the slightly higher impedance of the disposable pads.

  13. 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.

  14. Automated external defibrillator use for in-hospital emergency management.

    PubMed

    Huschak, G; Dünnebier, A; Kaisers, U X; Huschens, B; Bercker, S

    2016-05-01

    The in-hospital spread of automated external defibrillators (AEDs) is aimed to allow for a shock-delivery within three minutes. However, it has to be questioned if the implementation of AED alone really contributes to a 'heart-safe hospital'. We performed a cohort study of 1008 in-hospital emergency calls in a university tertiary care hospital, analysing cardiopulmonary resuscitation (CPR) cases with and without AED use. In total, 484 patients (48%) had cardiac arrest and received CPR. Response time of the emergency team was 4.3 ± 4.0 minutes. Only 8% percent of the CPR cases had a shockable rhythm. In three of 43 placements a shock was delivered by the AED. There were no differences in survival between patients with CPR only and CPR with AED use. Our data do not support the use of an AED for in-hospital CPR if a professional response team is rapidly available. PMID:27246934

  15. 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 trial.

    PubMed

    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

    2014-12-01

    We report the challenges of the Working to Improve Discussions About Defibrillator Management 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 (1) to increase ICD deactivation conversations, (2) to increase the number of ICDs deactivated, and (3) to 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 HF providers. We encountered three implementation barriers. First, there were institutional review board concerns at two sites because of the palliative nature of the study. Second, we had difficulty in creating entry criteria that accurately identified an 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.

  16. The effect of time on CPR and automated external defibrillator skills in the Public Access Defibrillation Trial

    PubMed Central

    Christenson, Jim; Nafziger, Sarah; Compton, Scott; Vijayaraghavan, Kris; Slater, Brian; Ledingham, Robert; Powell, Judy; McBurnie, Mary Ann

    2009-01-01

    Background The time to skill deterioration between primary training/retraining and further retraining in Cardiopulmonary resuscitation (CPR) and automated external defibrillation (AED) for lay-persons is unclear. The Public Access Defibrillation (PAD) Trial was a multi-center randomized controlled trial evaluating survival after CPR-only vs. CPR+AED delivered by onsite non-medical volunteer responders in out-of-hospital cardiac arrest. Aims This sub-study evaluated the relationship of time between primary training/retraining and further retraining on volunteer performance during pretest AED and CPR skill evaluation. Methods Volunteers at 1260 facilities in 24 North American regions underwent training/retraining according to facility randomization, which included an initial session and a refresher session at approximately 6 months. Before the next retraining, a CPR and AED skill test was completed for 2729 volunteers. Primary outcome for the study was assessment of global competence of CPR or AED performance (adequate vs not adequate) using Chi-square tests for trends by time interval (3, 6, 9, and 12 months). Confirmatory (GEE) logistic regression analysis, adjusted for site and potential confounders. Results The proportion of volunteers judged to be competent did not diminish by interval (3,6,9,12 months) for either CPR or AED skills. After adjusting for site and potential confounders, longer intervals before to further retraining was associated with a slightly lower likelihood of performing adequate CPR but not with AED scores. Conclusions After primary training/retraining, the CPR skills of targeted lay responders deteriorate nominally but 80% remain competent up to one year. AED skills do not significantly deteriorate and 90% of volunteers remain competent up to one year. PMID:17303309

  17. Cochlear Implants

    MedlinePlus

    ... electrodes are inserted. The electronic device at the base of the electrode array is then placed under ... FDA approval for implants The Food and Drug Administration (FDA) regulates cochlear implant devices for both adults ...

  18. 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.

  19. Coping with Trauma and Stressful Events As a Patient with an Implantable Cardioverter-Defibrillator

    MedlinePlus

    ... 29, 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. ...

  20. 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 . ...

  1. 77 FR 20873 - Qualification of Drivers; Application for Exemptions; Implantable Cardioverter Defibrillators

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-06

    ... on January 17, 2008 (73 FR 3316), or you may visit http://edocket.access.gpo.gov/2008/pdf/E8-785.pdf... final rule implementing section 4007 (69 FR 51589). Under this rule, FMCSA must publish a notice of each... person has no current clinical diagnosis of myocardial infarction, angina pectoris,...

  2. Firing of an Implantable Cardiac Defibrillator: An Unusual Presentation of Celiac Crisis

    PubMed Central

    Katz, Jeffry; Liu, Wendy

    2016-01-01

    Celiac crisis, an atypical presentation of celiac disease, is characterized by acute diarrhea and severe metabolic derangements. This diagnosis is often missed in the differential of acute diarrheal illness. Our patient is a 69-year-old man who presented with ICD firing and was found to have profound metabolic derangements. Further evaluation revealed undiagnosed celiac disease and his symptoms resolved with a gluten-free diet. Celiac crisis should be considered in all patients presenting with acute diarrhea, metabolic acidosis, and severe electrolyte abnormalities as management can be life-saving. PMID:27761475

  3. Prevention of infections in cardiovascular implantable electronic devices beyond the antibiotic agent.

    PubMed

    De Maria, Elia; Diemberger, Igor; Vassallo, Pier L; Pastore, Monica; Giannotti, Federica; Ronconi, Cinzia; Romandini, Andrea; Biffi, Mauro; Martignani, Cristian; Ziacchi, Matteo; Bonfatti, Federica; Tumietto, Fabio; Viale, Pierluigi; Boriani, Giuseppe

    2014-07-01

    The increase in incidence/prevalence of infections of implantable pacemakers and defibrillators (implantable cardioverter defibrillator, ICD) is outweighing that of the implanting procedures, mainly favored by the changes in patient profile. Despite the high impact on patient's outcome and related costs for healthcare systems, we lack specific evidence on the preventive measures with the exception of antibiotic prophylaxis. The aim of this study is to focus on common approaches to pacemaker/ICD implantation to identify the practical preventive strategies and choices that can (potentially) impact on the occurrence of this feared complication. After a brief introduction on clinical presentation, pathogenesis, and risk factors, we will present the results from a survey on the preventive strategies adopted by different operators from the 25 centers of the Emilia Romagna region in the northern Italy (4.4 million inhabitants). These data will provide the basis for reviewing available literature on this topic and identifying the gray areas. The last part of the article will cover the available evidence about pacemaker/ICD implantation, focusing on prophylaxis of pacemaker/ICD infection as a 'continuum' starting before the surgical procedure (from indications to patient preparation), which follows during (operator, room, and techniques) and after the procedure (patient and device follow-up). We will conclude by evaluating the relationship between adherence to the available evidence and the volume of procedures of the implanting centers or operators' experience according to the results of our survey. PMID:24838036

  4. Automatic Stabilization

    NASA Technical Reports Server (NTRS)

    Haus, FR

    1936-01-01

    This report lays more stress on the principles underlying automatic piloting than on the means of applications. Mechanical details of servomotors and the mechanical release device necessary to assure instantaneous return of the controls to the pilot in case of malfunction are not included. Descriptions are provided of various commercial systems.

  5. Surgical Management of the Patient with an Implanted Cardiac Device

    PubMed Central

    Madigan, John D.; Choudhri, Asim F.; Chen, Jonathan; Spotnitz, Henry M.; Oz, Mehmet C.; Edwards, Niloo

    1999-01-01

    Objective To identify the sources of electromagnetic interference (EMI) that may alter the performance of implanted cardiac devices and develop strategies to minimize their effects on patient hemodynamic status. Summary Background Data Since the development of the sensing demand pacemaker, EMI in the clinical setting has concerned physicians treating patients with such devices. Implanted cardiovertor defibrillators (ICDs) and ventricular assist devices (VADs) can also be affected by EMI. Methods All known sources of interference to pacemakers, ICDs, and VADs were evaluated and preventative strategies were devised. Results All devices should be thoroughly evaluated before and after surgery to make sure that its function has not been permanently damaged or changed. If electrocautery is to be used, pacemakers should be placed in a triggered or asynchronous mode; ICDs should have arrhythmia detection suspended before surgery. If defibrillation is to be used, the current flow between the paddles should be kept as far away from and perpendicular to the lead system as possible. Both pacemakers and ICDs should be properly shielded if magnetic resonance imaging, positron emission tomography, or radiation therapy is to be used. The effect of EMI on VADs depends on the model. Magnetic resonance imaging adversely affects all VADs except the Abiomed VAD, and therefore its use should be avoided in this population of patients. Conclusions The patient with an implanted cardiac device can safely undergo surgery as long as certain precautions are taken. PMID:10561087

  6. [Hearing implants].

    PubMed

    Stokroos, Robert J; George, Erwin L J

    2013-01-01

    In the Netherlands, more than 1.5 million people suffer from sensorineural hearing loss or deafness. However, fitting conventional hearing aids does not provide a solution for everyone. In recent decades, developments in medical technology have produced implantable and other devices that restore both sensorineural and conductive hearing losses. These hearing devices can be categorized into bone conductive devices, implantable middle ear prostheses, cochlear implants and auditory brainstem implants. Furthermore, new implants aimed at treating tinnitus and loss of vestibular function have recently been developed.

  7. The Public Access Defibrillation (PAD) trial: study design and rationale.

    PubMed

    Ornato, Joseph P; McBurnie, Mary Ann; Nichol, Graham; Salive, Marcel; Weisfeldt, Myron; Riegel, Barbara; Christenson, James; Terndrup, Thomas; Daya, Mohamud

    2003-02-01

    The PAD Trial is a prospective, multicenter, randomized clinical study testing whether volunteer, non-medical responders can improve survival from out-of-hospital cardiac arrest (OOH-CA) by using automated external defibrillators (AEDs). These lay volunteers, who have no traditional responsibility to respond to a medical emergency as part of their primary job description, will form part of a comprehensive, integrated community approach to the treatment of OOH-CA. The study is being conducted at 24 field centers in the United States and Canada. Approximately 1000 community units (e.g. apartment or office buildings, gated communities, sports facilities, senior centers, shopping malls, etc.) were randomized to treatment by trained laypersons who will provide either cardiopulmonary resuscitation (CPR) alone or CPR plus use of an AED, while awaiting arrival of the community's emergency medical services responders. The primary endpoint is the number of OOH-CA victims who survive to hospital discharge. Secondary endpoints include neurological status, health-related quality of life (HRQL), cost, and cost-effectiveness. Data collection will last approximately 15 months and is expected to be completed in September 2003.

  8. 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.

  9. Exercise Rehabilitation for Chronic Heart Failure Patients with Cardiac Device Implants

    PubMed Central

    Haennel, Robert G.

    2012-01-01

    In the past decade a significant development in the management and rehabilitation of people with chronic heart failure (CHF) has been the utilization of cardiac devices. The use of biventricular pacemakers, referred to as Cardiac Resynchronization Therapy (CRT) can yield improvements in functional abilities for a select group of CHF patients and the inclusion of implantable cardiac defibrillators (ICDs) may reduce the risk of sudden death. This review provides physical therapists with a basic understanding of how to prescribe exercise for people with CHF who have these device implants. PMID:22993499

  10. 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

  11. Increased defibrillator therapies during influenza season in patients without influenza vaccines

    PubMed Central

    Singh, Sheldon M.; de Souza, Russell J.; Kumareswaran, Ramanan

    2015-01-01

    Background The association between influenza vaccination and implantable cardiac defibrillator (ICD) therapies during influenza season is not known and is described in this study. Understanding this association is important since reduction in ICD therapies during influenza season via use of influenza vaccination would benefit patients physically and psychologically. Methods Patients presenting to the Sunnybrook Health Sciences Center ICD clinic between September 1st, 2011 and November 31st, 2011 were asked to complete a survey evaluating their use of the influenza vaccine. The number of patients with any ICD therapy and the total number of ICD therapies in the six months before and the three months during the 2010–2011 influenza season were determined. Poisson regression analysis was employed to assess differences in the average number of ICD therapies received during the influenza season based on vaccine status (vaccinated vs. unvaccinated). The analysis was repeated after limiting the cohort to patients with a left ventricular ejection fraction ≤35%. Results A total of 229 patients completed the survey, 78% of whom received the influenza vaccine. Four patients had more than one ICD shock during the study period. Electrical storm was rare (n=2). A trend toward more ICD therapies (unadjusted incident rate ratio (IRR)=3.2; P=0.07) and appropriate ICD shocks (unadjusted IRR=9.0; P=0.17) was noted for unvaccinated compared to vaccinated patients. This association persisted when analysis was limited to patients with a left ventricular ejection fraction ≤35% (all ICD therapies: unadjusted IRR=5.8; P=0.045; adjusted IRR=2.6; P=0.33). No patient who received the influenza vaccine, and had a reduced ejection fraction, received an approprite ICD shock during influenza season (unadjusted P<0.002). Conclusion A trend toward more ICD therapies during influenza season was observed in patients who did not receive the influenza vaccine compared to those who did. The

  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 stabilization

    NASA Technical Reports Server (NTRS)

    Haus, FR

    1936-01-01

    This report concerns the study of automatic stabilizers and extends it to include the control of the three-control system of the airplane instead of just altitude control. Some of the topics discussed include lateral disturbed motion, static stability, the mathematical theory of lateral motion, and large angles of incidence. Various mechanisms and stabilizers are also discussed. The feeding of Diesel engines by injection pumps actuated by engine compression, achieves the required high speeds of injection readily and permits rigorous control of the combustible charge introduced into each cylinder and of the peak pressure in the resultant cycle.

  14. 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.

  15. Histrelin Implant

    MedlinePlus

    ... response to histrelin implant. Your blood sugar and glycosylated hemoglobin (HbA1c) should be checked regularly.Ask your pharmacist any questions you have about histrelin implant.It is important for you to keep a written list of all of the prescription and ...

  16. 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.

  17. 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.

  18. Determination of safety factor for defibrillator waveforms in cultured heart cells.

    PubMed

    Jones, J L; Jones, R E

    1982-04-01

    We studied excitation thresholds and arrhythmias produced in cultured chick embryo myocardial cells subjected to electric shocks using rectangular, untruncated resistor-capacitor (RC), and critically damped resistor-inductor-capacitor (RLC) waveforms with variable intensities while photocell mechanograms were recorded. Strength-duration curves for excitation and production of a specific postshock arrhythmia (4-s arrest) were constructed. Excitation curves closely resembled those for in situ defibrillation threshold (or specific % success). The ratio between the shock intensity producing a 4-s arrest and that producing excitation at each duration (termed the "safety factor") was determined. Waveforms with a large safety factor in vitro defibrillated most effectively in situ with little postshock dysfunction. Waveforms with low safety factors had a low rate of success in situ and produced much postshock dysfunction. Safety factor of monophasic clinical waveforms were lower than that of the 5-ms rectangular wave. The close correspondence between in vitro safety factor and in situ defibrillating effectiveness, as reported in the literature, suggests that the cell culture system is an effective screening system for determining waveforms that will improve the efficacy and safety of defibrillation procedures. PMID:7065279

  19. 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…

  20. Determination of safety factor for defibrillator waveforms in cultured heart cells.

    PubMed

    Jones, J L; Jones, R E

    1982-04-01

    We studied excitation thresholds and arrhythmias produced in cultured chick embryo myocardial cells subjected to electric shocks using rectangular, untruncated resistor-capacitor (RC), and critically damped resistor-inductor-capacitor (RLC) waveforms with variable intensities while photocell mechanograms were recorded. Strength-duration curves for excitation and production of a specific postshock arrhythmia (4-s arrest) were constructed. Excitation curves closely resembled those for in situ defibrillation threshold (or specific % success). The ratio between the shock intensity producing a 4-s arrest and that producing excitation at each duration (termed the "safety factor") was determined. Waveforms with a large safety factor in vitro defibrillated most effectively in situ with little postshock dysfunction. Waveforms with low safety factors had a low rate of success in situ and produced much postshock dysfunction. Safety factor of monophasic clinical waveforms were lower than that of the 5-ms rectangular wave. The close correspondence between in vitro safety factor and in situ defibrillating effectiveness, as reported in the literature, suggests that the cell culture system is an effective screening system for determining waveforms that will improve the efficacy and safety of defibrillation procedures.

  1. Successful use of wearable cardioverter defibrillator in a patient with dextrocardia and persistent left superior vena cava.

    PubMed

    Wan, Chingping; Oren, Jess W; Szymkiewicz, Steven J

    2013-09-01

    Congenital disorders, such as dextrocardia and persistent left superior vena cava, are rare. However, their presence is often associated with other cardiac anomalies, and may lead to lethal ventricular tachyarrhythmias, which result in sudden cardiac death. Treating patients with these disorders can present a challenge to clinicians, as it may cause technical difficulties during interventional procedures, and more often, altered defibrillation techniques in a setting of prehospital sudden cardiac arrest. This report describes the first case of successful defibrillation therapy delivered by the wearable cardioverter defibrillator to a patient with dextrocardia and persistent left superior vena cava during a ventricular tachycardia arrest.

  2. Battery drain in daily practice and medium-term projections on longevity of cardioverter-defibrillators: an analysis from a remote monitoring database

    PubMed Central

    Boriani, Giuseppe; Ritter, Philippe; Biffi, Mauro; Ziacchi, Matteo; Diemberger, Igor; Martignani, Cristian; Valzania, Cinzia; Valsecchi, Sergio; Padeletti, Luigi; Gadler, Fredrik

    2016-01-01

    Aims The longevity of generators is a crucial determinant of the cost-effectiveness of therapy with implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy defibrillators (CRT-D). We evaluated the trend of device-measured residual battery capacity and longevity projections over 5-year follow-up. We also investigated possible factors associated with battery drain. Methods and results Data from 4851 patients in the European LATITUDE® database who were followed up for a minimum of 3 years were analysed. The factors associated with battery drain (i.e. year-to-year decrease in residual battery capacity), and thus potentially impacting on device longevity, were mainly the pacing parameters in CRT-D devices and the number of shocks delivered and diverted in both ICD and CRT-D (all P < 0.01 on linear regression analysis). Over the first 5 years, the longevity estimates provided by devices showed low intra-patient variability and increased with time. The estimates exceeded 10 years for CRT-D and 13 and 12 years for single- and dual-chamber ICDs, respectively. In CRT-D patients, the expected patient age on replacement was 80 ± 12 years, and the expected probability of undergoing device replacement was 63 ± 13% for New York Heart Association (NYHA) II patients and 37 ± 16% for NYHA III patients. For comparison, the probabilities of replacing a CRT-D lasting 5 years were 78 ± 8 and 59 ± 13%, respectively (both P < 0.001). Conclusion Battery drain was mainly associated with pacing output in CRT-D devices and with the number of capacitor charges in both ICD and CRT-D devices. The longevity estimates provided by the devices were consistent and conservative. According to these estimates, among CRT-D recipients a low proportion of patients should require device replacement. PMID:26847076

  3. 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.

  4. Cardiac or Other Implantable Electronic Devices and Sleep-disordered Breathing – Implications for Diagnosis and Therapy

    PubMed Central

    Bitter, Thomas; Gutleben, Klaus-Jürgen; Horstkotte, Dieter; Oldenburg, Olaf

    2014-01-01

    Sleep-disordered breathing (SDB) is of growing interest in cardiology because SDB is a highly prevalent comorbidity in patients with a variety of cardiovascular diseases. The prevalence of SDB is particularly high in patients with cardiac dysrhythmias and/or heart failure. In this setting, many patients now have implantable cardiac devices, such as pacemakers, implantable cardioverter-defibrillators or implanted cardiac resynchronisation therapy devices (CRT). Treatment of SDB using implantable cardiac devices has been studied previously, with atrial pacing and CRT being shown not to bring about satisfactory results in SDB care. The latest generations of these devices have the capacity to determine transthoracic impedance, to detect and quantify breathing efforts and to identify SDB. The capability of implantable cardiac devices to detect SDB is of potential importance for patients with cardiovascular disease, allowing screening for SDB, monitoring of the course of SDB in relation to cardiac status, and documenting of the effects of treatment. PMID:26835077

  5. 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. PMID:25387600

  6. Cochlear implant

    MedlinePlus

    ... implant. These specialists may include: Audiologists Speech therapists Ear, nose, and throat doctors (otolaryngologists) This is a very important part of the process. You will need to work closely with your team of specialists to get ...

  7. Cochlear Implants

    MedlinePlus

    ... additional visits are needed for activating, adjusting, and programming the various electrodes that have been implanted. Also, ... to the center for checkups once the final programming is made to the speech processor. Both children ...

  8. 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.

  9. 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

  10. 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.

  11. Defibrillation time intervals and outcomes of cardiac arrest in hospital: retrospective cohort study from Get With The Guidelines-Resuscitation registry

    PubMed Central

    Liu, Wenhui; Chan, Paul S; Nallamothu, Brahmajee K; Grunwald, Gary K; Self, Alyssa; Sasson, Comilla; Varosy, Paul D; Anderson, Monique L; Schneider, Preston M; Ho, P Michael

    2016-01-01

    Objective To describe temporal trends in the time interval between first and second attempts at defibrillation and the association between this time interval and outcomes in patients with persistent ventricular tachycardia or ventricular fibrillation (VT/VF) arrest in hospital. Design Retrospective cohort study Setting 172 hospitals in the United States participating in the Get With The Guidelines-Resuscitation registry, 2004-12. Participants Adults who received a second defibrillation attempt for persistent VT/VF arrest within three minutes of a first attempt. Interventions Second defibrillation attempts categorized as early (time interval of up to and including one minute between first and second defibrillation attempts) or deferred (time interval of more than one minute between first and second defibrillation attempts). Main outcome measure Survival to hospital discharge. Results Among 2733 patients with persistent VT/VF after the first defibrillation attempt, 1121 (41%) received a deferred second attempt. Deferred second defibrillation for persistent VT/VF increased from 26% in 2004 to 57% in 2012 (P<0.001 for trend). Compared with early second defibrillation, unadjusted patient outcomes were significantly worse with deferred second defibrillation (57.4% v 62.5% for return of spontaneous circulation, 38.4% v 43.6% for survival to 24 hours, and 24.7% v 30.8% for survival to hospital discharge; P<0.01 for all comparisons). After risk adjustment, deferred second defibrillation was not associated with survival to hospital discharge (propensity weighting adjusted risk ratio 0.89, 95% confidence interval 0.78 to 1.01; P=0.08; hierarchical regression adjusted 0.92, 0.83 to 1.02; P=0.1). Conclusions Since 2004, the use of deferred second defibrillation for persistent VT/VF in hospital has doubled. Deferred second defibrillation was not associated with improved survival. PMID:27052620

  12. 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

  13. Effective date of requirement for premarket approval for automated external defibrillator systems. Final rule.

    PubMed

    2015-01-29

    The Food and Drug Administration (FDA or the Agency) is issuing a final order to require the filing of premarket approval applications (PMA) for automated external defibrillator (AED) systems, which consist of an AED and those AED accessories necessary for the AED to detect and interpret an electrocardiogram and deliver an electrical shock (e.g., pad electrodes, batteries, adapters, and hardware keys for pediatric use). PMID:25730922

  14. Superiority of Biphasic Over Monophasic Defibrillation Shocks is Attributable to Less Intracellular Calcium Transient Heterogeneity

    PubMed Central

    Hwang, Gyo-Seung; Tang, Liang; Joung, Boyoung; Morita, Norishige; Hayashi, Hideki; Karagueuzian, Hrayr S.; Weiss, James N.; Lin, Shien-Fong; Chen, Peng-Sheng

    2008-01-01

    Objectives To test the hypothesis that superiority of biphasic waveform (BW) over monophasic waveform (MW) defibrillation shocks is attributable to less intracellular calcium (Cai) transient heterogeneity. Background The mechanism by which BW shocks have a higher defibrillation efficacy than MW shocks remains unclear. Methods We simultaneously mapped epicardial membrane potential (Vm) and Cai during 6 ms MW and 3/3 ms BW shocks in 19 Langendorff-perfused rabbit ventricles. After shock, the percentage of depolarized area was plotted over time. The maximum (peak) postshock values (VmP and CaiP, respectively) were used to measure heterogeneity. Higher VmP and CaiP imply less heterogeneity. Results The defibrillation threshold was for BW and MW shocks were 288±99 V and 399±155 V, respectively (p=0.0005). Successful BW shocks had higher VmP (88±9 %) and CaiP (70±13 %) than unsuccessful MW shocks (VmP 76 %±10, p<0.001; CaiP, 57±8 %, p<0.001) of the same shock strength. In contrast, for unsuccessful BW and MW shocks of the same shock strengths, the VmP and CaiP were not significantly different. MW shocks more frequently created regions of low Cai surrounded by regions of high Cai (postshock Cai sinkholes). The defibrillation threshold for MW and BW shocks became similar after disabling the sarcoplasmic reticulum with thapsigargin and ryanodine. Conclusions The greater efficacy of BW shocks is directly related to their less heterogeneous effects on shock-induced sarcoplasmic reticulum Ca release and Cai transients. Less heterogeneous Cai transients reduces the probability of Cai sinkhole formation, thereby preventing the postshock reinitiation of VF. PMID:18755345

  15. [A comparison of the two schemes of protection of the electrocardiograph against defibrillator impulse].

    PubMed

    Lebedev, V V

    2004-01-01

    Two typical scheme of protection of the input cascade of the electrocardiograph against defibrillator impulses are under consideration. It is concluded that the conditions of check-up and testing as envisaged in State Standard R 50267.25 (MEK 601-2-25-93), is not in line with the real operation conditions, therefore, appropriate changes are suggested to be made in the above Standard. The offered scheme is shown to ensure a decrease of the electrodes' polarization potential by 100 times.

  16. Hypersensitivity reactions to metallic implants - diagnostic algorithm and suggested patch test series for clinical use.

    PubMed

    Schalock, Peter C; Menné, Torkil; Johansen, Jeanne D; Taylor, James S; Maibach, Howard I; Lidén, Carola; Bruze, Magnus; Thyssen, Jacob P

    2012-01-01

    Cutaneous and systemic hypersensitivity reactions to implanted metals are challenging to evaluate and treat. Although they are uncommon, they do exist, and require appropriate and complete evaluation. This review summarizes the evidence regarding evaluation tools, especially patch and lymphocyte transformation tests, for hypersensitivity reactions to implanted metal devices. Patch test evaluation is the gold standard for metal hypersensitivity, although the results may be subjective. Regarding pre-implant testing, those patients with a reported history of metal dermatitis should be evaluated by patch testing. Those without a history of dermatitis should not be tested unless considerable concern exists. Regarding post-implant testing, a subset of patients with metal hypersensitivity may develop cutaneous or systemic reactions to implanted metals following implant. For symptomatic patients, a diagnostic algorithm to guide the selection of screening allergen series for patch testing is provided. At a minimum, an extended baseline screening series and metal screening is necessary. Static and dynamic orthopaedic implants, intravascular stent devices, implanted defibrillators and dental and gynaecological devices are considered. Basic management suggestions are provided. Our goal is to provide a comprehensive reference for use by those evaluating suspected cutaneous and systemic metal hypersensitivity reactions.

  17. 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

  18. 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

  19. Characterization of available automated external defibrillators in the market based on the product manuals in 2014

    PubMed Central

    Ho, Chik Leung; Cheng, Ka Wai; Ma, Tze Hang; Wong, Yau Hang; Cheng, Ka Lok; Kam, Chak Wah

    2016-01-01

    BACKGROUND: To popularize the wide-spread use of automated external defibrillator (AED) to save life in sudden cardiac arrest, we compared the strength and weakness of different types of AEDs to enable a sound selection based on regional requirement. METHODS: This was a retrospective descriptive study. Different types of AEDs were compared according to the information of AEDs from manuals and brochures provided by the manufacturers. Fifteen types of AEDs were divided into 3 groups, basic, intermediate and advanced. RESULTS: Lifeline™ AUTO AED had the best performance in price, portability and user-friendly among AEDs of basic level. It required less time for shock charging. Samaritan PAD defibrillator was superior in price, portability, durability and characteristic among AEDs of intermediate level. It had the longest warranty and highest protection against water and dust. Lifeline™ PRO AED had the best performance in most of the criteria among AEDs of advanced level and offered CPR video and manual mode for laypersons and clinicians respectively. CONCLUSION: Lifeline™ AUTO AED, Samaritan PAD defibrillator, Lifeline™ PRO AED are superior in AEDs of basic, intermediate and advanced levels, respectively. A feasible AED may be chosen by users according to the regional requirement and the current information about the best available products. PMID:27313810

  20. Implanted endocardial lead characteristics and risk of stroke or transient ischemic attack

    PubMed Central

    Vaidya, Vaibhav R.; DeSimone, Christopher V.; Chandra, Vishnu M.; Noheria, Amit; Hodge, David O.; Slusser, Joshua P.; Rabinstein, Alejandro A.; Friedman, Paul A.

    2015-01-01

    Introduction Patent foramen ovale (PFO) has been recently implicated as a strong predictor of stroke or transient ischemic attack (TIA) in patients with implanted pacemaker or defibrillation leads. Leads in the right heart can form thrombi that embolize to the pulmonary circulation and raise pulmonary pressure. This increases right-to-left shunting through PFO or intrapulmonary shunts and can result in paradoxical embolism. We sought to determine whether certain lead characteristics confer a higher thrombogenic risk resulting in stroke/ TIAs in patients either with or without a PFO. Methods We retrospectively analyzed 5,646 patients (mean age 67.3±16.3 years, 64 % male) who had endocardial device leads implanted in 2000–2010. We performed univariate and multivariate-adjusted proportional hazards models to determine association of lead characteristics with stroke/TIA during follow-up. Results On univariate analysis, passively fixated tined leads were associated with more stroke/TIAs (HR 1.77, 95 % CI 1.27, 2.47; p<0.001), whereas presence of defibrillation coil was associated with fewer stroke/TIAs (HR 0.59, 95 % CI 0.42–0.84; p=0.003). Number of leads per patient, presence of atrial lead, maximum lead size, tip shape, and type of insulating material were not associated with stoke/TIA. On multivariate analyses adjusting for age, sex, diagnosis of PFO, and prior history of stroke/TIA, the presence of tined leads was associated with stroke/TIA (HR 1.41, 95 % CI 1.00–1.97; p=0.049). Defibrillation coils were no longer associated with lower stroke/TIA on multivariate analysis. Conclusions Most physical characteristics of contemporary leads do not impact rate of stroke/TIA among patients receiving implantable devices. The presence of a PFO is a major risk factor for stroke/TIA in patients with endovascular leads. PMID:24771226

  1. 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

  2. Facial implants.

    PubMed

    Arcuri, M R; Rubenstein, J T

    1998-01-01

    The application of endosseous dental implants for the retention and stabilization of extraoral prostheses and hearing aids has been shown to be effective functionally and aesthetically. Implants have reduced the need for adhesive use, simplifying cleaning procedures and thus extending the life of the prosthesis. Implant-retained prostheses have provided patients the opportunity to participate in routine activities such as work, shopping, swimming, and jogging with less fear of losing their prosthesis. The implants' impact on patients has resulted in their ability to function in society with confidence that their defects will be less noticeable and their ability to respond to the environment enhanced. The culmination of these effects have without doubt improved the overall quality of life for patients. As with any new technology, its application will encounter unanticipated problems and some limitations in use. As the art and science of this technique evolve, however, it is anticipated that it will result in the ability to provide improved health care for patients.

  3. del Nido versus St. Thomas Cardioplegia Solutions: A Single-Center Retrospective Analysis of Post Cross-Clamp Defibrillation Rates.

    PubMed

    Buel, Shane T; Striker, Carrie Whittaker; O'Brien, James E

    2016-06-01

    There are many cardioplegia solutions currently in use for pediatric cardiopulmonary bypass (CPB). The most common being del Nido solution. Another common cardioplegia solution used for pediatric CPB is St. Thomas. In October 2014, Children's Mercy Kansas City changed from the use of modified St. Thomas to del Nido. This study compared rates of post cross-clamp fibrillation requiring defibrillation between del Nido solution and modified St. Thomas solution stratified by weight at Children's Mercy Kansas City. This retrospective study consisted of 394 patients who underwent cardiac surgery requiring cardioplegia between January 1, 2014 and July 31, 2015. The outcome measured was defibrillation upon cross-clamp removal. Statistical significance was determined using Fishers exact test with a two-sided significance level of .05. Incidence of defibrillation post cross-clamp removal was 4.4% in the del Nido group and 26.8% in the St. Thomas group (p < .0001). Analysis by weight stratifications displays a reduction in post cross-clamp defibrillation rates in groups using the del Nido solution. The 0- to 6-kg category had an incidence of fibrillation of 1.23% in the del Nido group and 17.5% in the St. Thomas group (p < .0003). The 6- to 15-kg category had an incidence of defibrillation of 1.82% in the del Nido group and 14% in the St. Thomas group (p < .0198). The 15- to 60-kg category had an incidence of defibrillation of 8.9% in the del Nido group and 61% in the St. Thomas group (p < .0001). The >60-kg category had an incidence of defibrillation of 16.7% in the del Nido group and 63% in the St. Thomas group (p < .0623). This study demonstrates a 6-fold decrease in the overall rate of defibrillation post cross-clamp removal between St. Thomas and del Nido cardioplegia solutions. Analyses of weight stratifications demonstrate a decrease in the rate of defibrillation post cross-clamp removal in all categories within the del Nido group. PMID:27578896

  4. Computer methods for automating preoperative dental implant planning: implant positioning and size assignment.

    PubMed

    Galanis, Christos C; Sfantsikopoulos, Michael M; Koidis, Petros T; Kafantaris, Nikolaos M; Mpikos, Pavlos G

    2007-04-01

    The paper presents computer-aided methods that allocate a dental implant and suggest its size, during the pre-operative planning stage, in conformance with introduced optimization criteria and established clinical requirements. Based on computed tomography data of the jaw and prosthesis anatomy, single tooth cases are planned for the best-suited implant insertion at a user-defined region. An optimum implantation axis line is produced and cylindrical implants of various candidate sizes are then automatically positioned, while their occlusal end is leveled to bone ridge, and evaluated. Radial safety margins are used for the assessment of the implant safety distance from neighboring anatomical structures and bone quantity and quality are estimated and taken into consideration. A case study demonstrates the concept and allows for its discussion.

  5. 41 CFR 102-79.115 - What guidelines must an agency follow if it elects to establish a public access defibrillation...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... SPACE Assignment and Utilization of Space Public Access Defibrillation Programs § 102-79.115 What... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false What guidelines must an agency follow if it elects to establish a public access defibrillation program in a Federal facility?...

  6. Relation between detection rate and inappropriate shocks in single versus dual chamber cardioverter-defibrillator--an analysis from the OPTION trial.

    PubMed

    Kolb, Christof; Sturmer, Marcio; Babuty, Dominique; Sick, Peter; Davy, Jean Marc; Molon, Giulio; Schwab, Jörg Otto; Mantovani, Giuseppe; Wickliffe, Andrew; Lennerz, Carsten; Semmler, Verena; Siot, Pierre-Henri; Reif, Sebastian

    2016-01-01

    The programming of implantable cardioverter-defibrillators (ICDs) influences inappropriate shock rates. The aim of the study is to analyse rates of patients with appropriate and inappropriate shocks according to detection zones in the OPTION trial. All patients received dual chamber (DC) ICDs randomly assigned to be programmed either to single chamber (SC) or to DC settings including PARAD+ algorithm. In a post-hoc analysis, rates of patients with inappropriate and appropriate shocks were calculated for shocks triggered at heart rates ≥ 170 bpm (ventricular tachycardia zone) and at rates ≥ 200 bpm (ventricular fibrillation zone). In the SC group, higher rates of patients with total and inappropriate shocks were delivered at heart rates ≥ 170 bpm than at rates ≥ 200 bpm (total shocks: 21.1% vs. 16.6%; p = 0.002; inappropriate shocks: 7.6% vs. 4.5%, p = 0.016; appropriate shocks: 15.2% vs. 13.5%; p = n.s.). No such differences were observed in the DC group (total shocks: 14.3% vs. 12.6%; p = n.s.; inappropriate shocks: 3.9% vs. 3.6%; p = n.s.; appropriate shocks: 12.2% vs. 10.4%; p = n.s.). The higher frequency of patients with total shocks with SC settings than with DC settings that benefit from PARAD+ was driven by a higher percentage of patients with inappropriate shocks in the VT zone (170-200 bpm) in the SC population. PMID:26892534

  7. 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

  8. 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

  9. Complications after cardiac implantable electronic device implantations: an analysis of a complete, nationwide cohort in Denmark

    PubMed Central

    Kirkfeldt, Rikke Esberg; Johansen, Jens Brock; Nohr, Ellen Aagaard; Jørgensen, Ole Dan; Nielsen, Jens Cosedis

    2014-01-01

    Aims Complications after cardiac implantable electronic device (CIED) treatment, including permanent pacemakers (PMs), cardiac resynchronization therapy devices with defibrillators (CRT-Ds) or without (CRT-Ps), and implantable cardioverter defibrillators (ICDs), are associated with increased patient morbidity, healthcare costs, and possibly increased mortality. Methods and results Population-based cohort study in all Danish patients who underwent a CIED procedure from May 2010 to April 2011. Data on complications were gathered on review of all patient charts while baseline data were obtained from the Danish Pacemaker and ICD Register. Adjusted risk ratios (aRRs) with 95% confidence intervals were estimated using binary regression. The study population consisted of 5918 consecutive patients. A total of 562 patients (9.5%) experienced at least one complication. The risk of any complication was higher if the patient was a female (aRR 1.3; 1.1–1.6), underweight (aRR 1.5; 1.1–2.3), implanted in a centre with an annual volume <750 procedures (0–249 procedures: aRR 1.6; 1.1–2.2, 250–499: aRR 2.0; 1.6–2.7, 500–749: aRR 1.5; 1.2–1.8), received a dual-chamber ICD (aRR 2.0; 1.4–2.7) or CRT-D (aRR 2.6; 1.9–3.4), underwent system upgrade or lead revision (aRR 1.3; 1.0–1.7), had an operator with an annual volume <50 procedures (aRR 1.9; 1.4–2.6), or underwent an emergency, out-of-hours procedure (aRR 1.5; 1.0–2.3). Conclusion CIED complications are more frequent than generally acknowledged. Both patient- and procedure-related predictors may identify patients with a particularly high risk of complications. This information should be taken into account both in individual patient treatment and in the planning of future organization of CIED treatment. PMID:24347317

  10. Activation during ventricular defibrillation in open-chest dogs. Evidence of complete cessation and regeneration of ventricular fibrillation after unsuccessful shocks.

    PubMed Central

    Chen, P S; Shibata, N; Dixon, E G; Wolf, P D; Danieley, N D; Sweeney, M B; Smith, W M; Ideker, R E

    1986-01-01

    To test the hypothesis that a defibrillation shock is unsuccessful because it fails to annihilate activation fronts within a critical mass of myocardium, we recorded epicardial and transmural activation in 11 open-chest dogs during electrically induced ventricular fibrillation (VF). Shocks of 1-30 J were delivered through defibrillation electrodes on the left ventricular apex and right atrium. Simultaneous recordings were made from septal, intramural, and epicardial electrodes in various combinations. Immediately after all 104 unsuccessful and 116 successful defibrillation shocks, an isoelectric interval much longer than that observed during preshock VF occurred. During this time no epicardial, septal, or intramural activations were observed. This isoelectric window averaged 64 +/- 22 ms after unsuccessful defibrillation and 339 +/- 292 ms after successful defibrillation (P less than 0.02). After the isoelectric window of unsuccessful shocks, earliest activation was recorded from the base of the ventricles, which was the area farthest from the apical defibrillation electrode. Activation was synchronized for one or two cycles following unsuccessful shocks, after which VF regenerated. Thus, after both successful and unsuccessful defibrillation with epicardial shocks of greater than or equal to 1 J, an isoelectric window occurs during which no activation fronts are present; the postshock isoelectric window is shorter for unsuccessful than for successful defibrillation; unsuccessful shocks transiently synchronize activation before fibrillation regenerates; activation leading to the regeneration of VF after the isoelectric window for unsuccessful shocks originates in areas away from the defibrillation electrodes. The isoelectric window does not support the hypothesis that defibrillation fails solely because activation fronts are not halted within a critical mass of myocardium. Rather, unsuccessful epicardial shocks of greater than or equal to 1 J halt all activation

  11. 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.

  12. 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.

  13. 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.

  14. Cochlear implants: selection criteria and shifting borders.

    PubMed

    Lenarz, T

    1998-01-01

    Cochlear implants have proven to be effective and reliable in postlingually deaf adults. This is also true for congenitally deaf and perilingually deaf children up to the age of six years. Due to the increasing experience, the improvement of implant technology and the proven reliability the selection criteria are broadened with shifting borders. The main extensions are related to age, additional handicaps, residual hearing and special etiologies of deafness. Increasing evidence shows that very early implantation results in better performance and better hearing and speech development. Near-normal language acquisition can be achieved in children implanted under the age of four. Additional handicaps do not automatically exclude a candidate from cochlear implantation. A case-to-case decision has to be made based on additional diagnostics and the experience of the implant centre. A list of suitable handicaps is provided. Severely hearing impaired patients may also be considered for cochlear implantation if their residual hearing provides no benefit for speech discrimination. The same holds true for children. Cochlear implantation in obliterated cochleae and inner ear malformation requires a special surgical technique and special electrode arrays. In this way even difficult cases can be managed with remarkable outcome. Over all, the selection criteria have been broadened with increasing experience and technological improvement. This development may continue and the borderline between hearing aids and cochlear implants will shift further towards severe hearing loss. However, the basis for success still remains good rehabilitation, a team approach and the willingness of the patient to undergo the whole process of cochlear implantation.

  15. 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

  16. 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.

  17. Cardiovascular implantable electronic device infections: associated risk factors and prevention.

    PubMed

    Rohacek, Martin; Baddour, Larry M

    2015-01-01

    Infections of cardiovascular implantable electric devices (CIED) are a burden on patients and healthcare systems and should be prevented. The most frequent pathogens are coagulase-negative staphylococci and Staphylococcus aureus. The most important risk factors for CIED infections are diabetes mellitus, renal and heart failure, corticosteroid use, oral anticoagulation, fever within 24 hours before the procedure and leucocytosis, implantable cardioverter defibrillator compared with pacemaker, especially in the case of Staphylococcus aureus bacteraemia, lack of antibiotic prophylaxis, and postoperative haematoma and other wound complications. Other important risk factors are history of prior procedures and previous CIED infections, number of leads, use of povidone-iodine compared with chlorhexidine-alcohol, and centres and operators with a low volume of implants. To prevent CIED infections, patients undergoing CIED procedures and appropriate devices should be carefully selected, and interventions should be performed by trained operators. Antibiotic prophylaxis should be administered, and skin antisepsis should be done with chlorhexidine-alcohol. Oral anticoagulation should be continued during CIED procedures in high-risk patients for thromboembolism, instead of bridging with heparin. Early reintervention in cases of haematoma or lead dislodgement should be avoided. The implementation of infection prevention programmes reduces infection rates. More randomised controlled studies are needed to evaluate prevention strategies, especially skin preparation and antibiotic prophylaxis with glycopeptides. PMID:26230056

  18. Enhanced detection criteria in implantable cardioverter defibrillators: sensitivity and specificity of the stability algorithm at different heart rates.

    PubMed

    Kettering, K; Dörnberger, V; Lang, R; Vonthein, R; Suchalla, R; Bosch, R F; Mewis, C; Eigenberger, B; Kühlkamp, V

    2001-09-01

    The lack of specificity in the detection of ventricular tachyarrhythmias remains a major clinical problem in the therapy with ICDs. The stability criterion has been shown to be useful in discriminating ventricular tachyarrhythmias characterized by a small variation in cycle lengths from AF with rapid ventricular response presenting a higher degree of variability of RR intervals. But RR variability decreases with increasing heart rate during AF. Therefore, the aim of the study was to determine if the sensitivity and specificity of the STABILITY algorithm for spontaneous tachyarrhythmias is related to ventricular rate. Forty-two patients who had received an ICD (CPI Ventak Mini I, II, III or Ventak AV) were enrolled in the study. Two hundred ninety-eight episodes of AF with rapid ventricular response and 817 episodes of ventricular tachyarrhythmias were analyzed. Sensitivity and specificity in the detection of ventricular tachyarrhythmias were calculated at different heart rates. When a stability value of 30 ms was programmed the result was a sensitivity of 82.7% and a specificity of 91.4% in the detection of slow ventricular tachyarrhythmias (heart rate < 150 beats/min). When faster ventricular tachyarrhythmias with rates between 150 and 169 beats/min (170-189 beats/min) were analyzed, a stability value of 30 ms provided a sensitivity of 94.5% (94.7%) and a specificity of 76.5% (54.0%). For arrhythmia episodes > or = 190 beats/min, the same stability value resulted in a sensitivity of 78.2% and a specificity of 41.0%. Even when other stability values were taken into consideration, no acceptable sensitivity/specificity values could be obtained in this subgroup. RR variability decreases with increasing heart rate during AF while RR variability remains almost constant at different cycle lengths during ventricular tachyarrhythmias. Thus, acceptable performance of the STABILITY algorithm appears to be limited to ventricular rate zones < 170 beats/min.

  19. Automatism and hypoglycaemia.

    PubMed

    Beaumont, Guy

    2007-02-01

    A case of a detained person (DP) suffering from insulin-dependent diabetes, who subsequently used the disorder in his defence as a reason to claim automatism, is discussed. The legal and medical history of automatism is outlined along with the present day situation. Forensic physicians should be aware when examining any diabetic that automatism may subsequently be claimed. With this in mind, the importance of relevant history taking specifically relating to diabetic control and symptoms is discussed.

  20. An anatomy of automatism.

    PubMed

    Mackay, R D

    2015-07-01

    The automatism defence has been described as a quagmire of law and as presenting an intractable problem. Why is this so? This paper will analyse and explore the current legal position on automatism. In so doing, it will identify the problems which the case law has created, including the distinction between sane and insane automatism and the status of the 'external factor doctrine', and comment briefly on recent reform proposals.

  1. An anatomy of automatism.

    PubMed

    Mackay, R D

    2015-07-01

    The automatism defence has been described as a quagmire of law and as presenting an intractable problem. Why is this so? This paper will analyse and explore the current legal position on automatism. In so doing, it will identify the problems which the case law has created, including the distinction between sane and insane automatism and the status of the 'external factor doctrine', and comment briefly on recent reform proposals. PMID:26378105

  2. Automatic crack propagation tracking

    NASA Technical Reports Server (NTRS)

    Shephard, M. S.; Weidner, T. J.; Yehia, N. A. B.; Burd, G. S.

    1985-01-01

    A finite element based approach to fully automatic crack propagation tracking is presented. The procedure presented combines fully automatic mesh generation with linear fracture mechanics techniques in a geometrically based finite element code capable of automatically tracking cracks in two-dimensional domains. The automatic mesh generator employs the modified-quadtree technique. Crack propagation increment and direction are predicted using a modified maximum dilatational strain energy density criterion employing the numerical results obtained by meshes of quadratic displacement and singular crack tip finite elements. Example problems are included to demonstrate the procedure.

  3. 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.

  4. 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.

  5. 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.

  6. 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. PMID:26996767

  7. Automatic Mode Switch (AMS) Causes Less Synchronization

    PubMed Central

    Jorat, Mohammadvahid; Nikoo, Mohammadhossein

    2016-01-01

    Introduction: Cardiac resynchronization devices are part of modern heart failure management. After implantation, we analyze and program devices in an attempt to ensure their success. Biventricular pacing should be 98% or more for the lowest mortality and best symptom improvement. Case Presentation: In this case series, we present a combination of far field sensing and automatic mode switching (AMS) in six patients. It is found that this combination causes ventricular sensing (VS) episodes with wide QRS and no synchronization. We turn off the AMS and alleviate the problem. Conclusions: Switching AMS off may increase biventricular pacing in some patients. PMID:26949695

  8. 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.

  9. 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)

  10. Radiated radiofrequency immunity testing of automated external defibrillators - modifications of applicable standards are needed

    PubMed Central

    2011-01-01

    Background We studied the worst-case radiated radiofrequency (RF) susceptibility of automated external defibrillators (AEDs) based on the electromagnetic compatibility (EMC) requirements of a current standard for cardiac defibrillators, IEC 60601-2-4. Square wave modulation was used to mimic cardiac physiological frequencies of 1 - 3 Hz. Deviations from the IEC standard were a lower frequency limit of 30 MHz to explore frequencies where the patient-connected leads could resonate. Also testing up to 20 V/m was performed. We tested AEDs with ventricular fibrillation (V-Fib) and normal sinus rhythm signals on the patient leads to enable testing for false negatives (inappropriate "no shock advised" by the AED). Methods We performed radiated exposures in a 10 meter anechoic chamber using two broadband antennas to generate E fields in the 30 - 2500 MHz frequency range at 1% frequency steps. An AED patient simulator was housed in a shielded box and delivered normal and fibrillation waveforms to the AED's patient leads. We developed a technique to screen ECG waveforms stored in each AED for electromagnetic interference at all frequencies without waiting for the long cycle times between analyses (normally 20 to over 200 s). Results Five of the seven AEDs tested were susceptible to RF interference, primarily at frequencies below 80 MHz. Some induced errors could cause AEDs to malfunction and effectively inhibit operator prompts to deliver a shock to a patient experiencing lethal fibrillation. Failures occurred in some AEDs exposed to E fields between 3 V/m and 20 V/m, in the 38 - 50 MHz range. These occurred when the patient simulator was delivering a V-Fib waveform to the AED. Also, we found it is not possible to test modern battery-only-operated AEDs for EMI using a patient simulator if the IEC 60601-2-4 defibrillator standard's simulated patient load is used. Conclusions AEDs experienced potentially life-threatening false-negative failures from radiated RF, primarily

  11. Utilization of YouTube as a Tool to Assess Patient Perception Regarding Implanted Cardiac Devices

    PubMed Central

    Hayes, Kevin; Mainali, Prajeena; Deshmukh, Abhishek; Pant, Sadip; Badheka, Apurva O; Paydak, Hakan

    2014-01-01

    Background: The outreach of YouTube may have a dramatic role in the widespread dissemination of knowledge on implantable cardioverter devices (ICD). Aims: This study was designed to review and analyze the information available on YouTube pertaining to implantable cardiac devices such as implantable cardioverter defibrillators (ICDs) and pacemakers. Materials and Methods: YouTube was queried for the terms “ICD”, “Implantable Cardioverter Defibrillator”, and “Pacemaker”. The videos were reviewed and categorized as according to content; number of views and “likes” or “dislikes” was recorded by two separate observers. Results: Of the 55 videos reviewed, 18 of the videos were categorized as patient education, 12 were advertisements, 8 were intraoperative videos documenting the device implantation procedures, 7 of the videos were produced to document personal patient experiences, and 4 were categorized as documentation of a public event. 3 were intended to educate health care workers. The remaining 3 were intended to raise public awareness about sudden cardiac death. The videos portraying intraoperative procedures generated the most “likes” or “dislikes” per view. Conclusion: While YouTube provides a logical platform for delivery of health information, the information on this platform is not regulated. Initiative by reputed authorities and posting accurate information in such platform can be a great aid in public education regarding device therapy. PMID:25077075

  12. 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

  13. Pacemaker and defibrillator deactivation in competent hospice patients: an ethical consideration.

    PubMed

    Ballentine, Jennifer M

    2005-01-01

    The Denver Community Bioethics Committee (DCBC) is an independent, community-based group that undertakes ethics consultations for any individual or organization. Its members include adult protection professionals, physicians, elder-law attorneys, chaplains, nurses, social workers, and lay persons. In its 11-year history, the Committee has heard numerous cases concerning end-of-life care, futile treatment, and patients' rights. In 2003, a Colorado hospice provider asked the DCBC for assistance in developing a policy on deactivation of pacemakers and defibrillators in competent hospice patients. The hospice had encountered concerns from some physicians and cardiac care clinicians that deactivating such devices treads the fine line between legitimate withdrawal of burdensome treatment and assisted death. Although the specific deliberations of the DCBC are confidential, this article summarizes contributions from the committee's discussion, as well as independent research undertaken by the author.

  14. 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.

  15. 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. PMID:1272088

  16. Cardiac Resynchronization Therapy Defibrillator Treatment in a Child with Heart Failure and Ventricular Arrhythmia.

    PubMed

    Kim, Hak Ju; Cho, Sungkyu; Kim, Woong-Han

    2016-08-01

    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

  17. Relation between detection rate and inappropriate shocks in single versus dual chamber cardioverter-defibrillator – an analysis from the OPTION trial

    PubMed Central

    Kolb, Christof; Sturmer, Marcio; Babuty, Dominique; Sick, Peter; Davy, Jean Marc; Molon, Giulio; Schwab, Jörg Otto; Mantovani, Giuseppe; Wickliffe, Andrew; Lennerz, Carsten; Semmler, Verena; Siot, Pierre-Henri; Reif , Sebastian

    2016-01-01

    The programming of implantable cardioverter-defibrillators (ICDs) influences inappropriate shock rates. The aim of the study is to analyse rates of patients with appropriate and inappropriate shocks according to detection zones in the OPTION trial. All patients received dual chamber (DC) ICDs randomly assigned to be programmed either to single chamber (SC) or to DC settings including PARAD+ algorithm. In a post-hoc analysis, rates of patients with inappropriate and appropriate shocks were calculated for shocks triggered at heart rates ≥170 bpm (ventricular tachycardia zone) and at rates ≥200 bpm (ventricular fibrillation zone). In the SC group, higher rates of patients with total and inappropriate shocks were delivered at heart rates ≥170 bpm than at rates ≥200 bpm (total shocks: 21.1% vs. 16.6%; p = 0.002; inappropriate shocks: 7.6% vs. 4.5%, p = 0.016; appropriate shocks: 15.2% vs. 13.5%; p = n.s.). No such differences were observed in the DC group (total shocks: 14.3% vs. 12.6%; p = n.s.; inappropriate shocks: 3.9% vs. 3.6%; p = n.s.; appropriate shocks: 12.2% vs. 10.4%; p = n.s.). The higher frequency of patients with total shocks with SC settings than with DC settings that benefit from PARAD+ was driven by a higher percentage of patients with inappropriate shocks in the VT zone (170–200 bpm) in the SC population. PMID:26892534

  18. 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.

  19. Implant success!!!.....simplified.

    PubMed

    Luthra, Kaushal K

    2009-01-01

    The endeavor towards life-like restoration has helped nurture new vistas in the art and science of implant dentistry. The protocol of "restoration-driven implant placement" ensures that the implant is an apical extension of the ideal future restoration and not the opposite. Meticulous pre-implant evaluation of soft and hard tissues, diagnostic cast and use of aesthetic wax-up and radiographic template combined with surgical template can simplify the intricate roadmap for appropriate implant treatment.By applying the harmony of artistic skill, scientific knowledge and clinical expertise, we can simply master the outstanding implant success in requisites of aesthetics, phonetics and function.

  20. Automatic and Flexible

    PubMed Central

    Hassin, Ran R.; Bargh, John A.; Zimerman, Shira

    2008-01-01

    Arguing from the nature of goal pursuit and from the economy of mental resources this paper suggests that automatic goal pursuit, much like its controlled counterpart, may be flexible. Two studies that employ goal priming procedures examine this hypothesis using the Wisconsin Card Sorting Test (Study 1) and a variation of the Iowa Gambling Task (Study 2). Implications of the results for our understanding of the dichotomy between automatic and controlled processes in general, and for our conception of automatic goal pursuit in particular, are discussed. PMID:19325712

  1. [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.

  2. Prevention of inappropriate ICD shocks due to lead insulation failure by continuous monitoring and automatic alert.

    PubMed

    Gelder, Robert N; Gunderson, Bruce D

    2012-06-01

    Patients with implantable cardioverter defibrillator lead insulation failures may present with oversensing and/or abnormal impedance. The Lead Integrity Alert (LIA) monitors right ventricular pace/sense leads using both continuous oversensing and daily impedance measurementd. Oversensing consists of isolated short R-R intervals and nonsustained runs of short R-R intervals. The LIA algorithm has been studied for Sprint Fidelis conductor fractures, but not for lead insulation failures. We report on a patient with a failed St. Jude Riata™ ST lead (St. Jude Medical, St. Paul, MN, USA) connected to a Medtronic Virtuoso DR (Medtronic Inc., Minneapolis, MN, USA) with the LIA. Oversensing triggered the LIA, while the impedance trend was normal.

  3. Automatic amino acid analyzer

    NASA Technical Reports Server (NTRS)

    Berdahl, B. J.; Carle, G. C.; Oyama, V. I.

    1971-01-01

    Analyzer operates unattended or up to 15 hours. It has an automatic sample injection system and can be programmed. All fluid-flow valve switching is accomplished pneumatically from miniature three-way solenoid pilot valves.

  4. AUTOMATIC MASS SPECTROMETER

    DOEpatents

    Hanson, M.L.; Tabor, C.D. Jr.

    1961-12-01

    A mass spectrometer for analyzing the components of a gas is designed which is capable of continuous automatic operation such as analysis of samples of process gas from a continuous production system where the gas content may be changing. (AEC)

  5. Automatic Payroll Deposit System.

    ERIC Educational Resources Information Center

    Davidson, D. B.

    1979-01-01

    The Automatic Payroll Deposit System in Yakima, Washington's Public School District No. 7, directly transmits each employee's salary amount for each pay period to a bank or other financial institution. (Author/MLF)

  6. Breast reconstruction - implants

    MedlinePlus

    ... visits, your surgeon injects a small amount of saline (salt water) through the valve into the expander. ... breast implants. Implants may be filled with either saline or a silicone gel. You may have another ...

  7. 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.

  8. Arrhythmic death and ICD implantation after myocardial infarction

    PubMed Central

    LOMBARDI, FEDERICO

    2006-01-01

    Arrhythmic death remains one of the most important causes of mortality after an acute myocardial infarction also in the revascularization era. As a consequence, identification of patients at risk should be performed before discharge. Unfortunately, in the clinical practice, this evaluation is mainly based on detection of a depressed left ventricular ejection. This approach, however, cannot adequately distinguish arrhythmic versus non-arrhythmic risk. This issue is of critical relevance when considering that arrhythmic death can be significantly reduced by appropriate interventions of implantable cardioverter defibrillator. Available evidence, however, indicates that in the first month after myocardial infarction, device implantation does not significantly reduce cardiac mortality: it seems that the reduction of arrhythmic death is counterbalanced by an increase in rate of death from non arrhythmic cause. It is therefore to be hoped that, in the future, arrhythmic risk evaluation will be based not only on the extent of left ventricular dysfunction but also on the analysis of other risk markers such as those reflecting autonomic dysfunction, cardiac electrical instability and presence of subclinical inflammation. PMID:21977246

  9. 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

  10. [Pathology of implants].

    PubMed

    Mittermayer, C; Eblenkamp, M; Richter, H A; Zwadlo-Klarwasser, G; Bhardwaj, R S; Klosterhalfen, B

    2002-01-01

    Progress in the surgery of implants and biomaterials can be accomplished by: 1. Painstakingly analysing and registering of defaulting implants after explantation within a "National Registry of Implant Pathology". 2. Development of a DNA-microarray named "Implantat/Chronic Wound" in order to discover the differential transcriptional activities of cells brought into contact with different foreign surfaces. 3. Predictive cell-engineering combined with custom-made implant surfaces with the aim of optimal patient care.

  11. Tunnel Propagation Following Defibrillation with ICD Shocks: Hidden Postshock Activations in the Left Ventricular Wall Underlie Isoelectric Window

    PubMed Central

    Constantino, Jason; Long, Yun; Ashihara, Takashi; Trayanova, Natalia A.

    2010-01-01

    Background Following near-defibrillation threshold (DFT) shocks from an ICD, the first postshock activation that leads to defibrillation failure arises focally after an isolelectric window (IW). The mechanisms underlying the IW remain incompletely understood. Objective The goal of this study was to provide mechanistic insight into the origins of postshock activations and IW following ICD shocks, and to link shock outcome to the preshock state of the ventricles. We hypothesized that the non-uniform ICD field results in the formation of an intramural excitable area (tunnel) only in the LV free wall, through which both pre-existing and new shock-induced wavefronts propagate during the IW. Methods Simulations were conducted using a realistic 3-D model of defibrillation in the rabbit ventricles. Biphasic ICD shocks of varying strengths were delivered to 27 different fibrillatory states. Results Following near-DFT shocks, regardless of preshock state, the main postshock excitable area was always located within LV free wall, creating an intramural tunnel. Either preexisting fibrillatory or shock-induced wavefronts propagated during the IW (duration of up to 74ms) in this tunnel and emerged as breakthroughs on LV epicardium. Preshock activity within the LV played a significant role in shock outcome: large number of preshock filaments resulted in an IW associated with tunnel propagation of preexisting rather than shock-induced wavefronts. Furthermore, shocks were more likely to succeed if LV excitable area was smaller. Conclusions The LV intramural excitable area is the primary reason for near-DFT failure. Any intervention that decreases the extent of this area will improve the likelihood of defibrillation success. PMID:20348028

  12. 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

  13. How Can Death Due to Sudden Cardiac Arrest Be Prevented?

    MedlinePlus

    ... heartbeats that can trigger the ICD. Implantable Cardioverter Defibrillator The illustration shows the location of an implantable cardioverter defibrillator in the upper chest. The electrodes are inserted ...

  14. Implantation in IVF.

    PubMed

    Busso, Cristiano E; Melo, Marco A B; Fernandez, Manuel; Pellicer, Antonio; Simon, Carlos

    2006-01-01

    The recent advances in assisted reproduction have made it possible to study and interfere in almost every step of the human reproductive process except for implantation. The most complex and important step remains in great part unknown. Implantation in human has proven to be less efficient compared with other species. However, in in vitro fertilization (IVF) patients, it has been evaluated to be even poorer. This paper highlights the factors related to infertile patients and IVF treatments that can affect implantation and implantation's clinical aspects related to these treatments: implantation failure and early pregnancy loss.

  15. 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.

  16. 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

  17. Breast implants. A review.

    PubMed

    Van Zele, D; Heymans, O

    2004-04-01

    Breast implants have been used for about four decades for both reconstructive and aesthetic purposes. In 1963, the quality of the artificial implants was revolutionized by the introduction of the silicone gel-filled implant. Since, this modern prosthesis has gone through an evolution of change and improvement with several types of devices with many variations and styles within each class. Actually, for the last three decades, approximately one million women have received silicone breast implants in the USA. But, in 1992, the American FDA banned silicone from the market, leaving saline implants as the only product generally available as an alternative until now. Other filler materials were introduced, but have never progressed beyond the experimental stage in the USA (in contrast with Europe). The evolution of the different implants through time, with their advantages and disadvantages will be discussed, but also the controversy on silicone implants in the USA and their suspected association with systemic diseases. PMID:15154572

  18. Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands.

    PubMed

    Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

    2016-06-21

    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. PMID:27224201

  19. 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.

  20. Effect of Continued Cardiac Resynchronization Therapy on Ventricular Arrhythmias After Left Ventricular Assist Device Implantation.

    PubMed

    Schleifer, John William; Mookadam, Farouk; Kransdorf, Evan P; Nanda, Udai; Adams, Jonathon C; Cha, Stephen; Pajaro, Octavio E; Steidley, David Eric; Scott, Robert L; Carvajal, Tomas; Saadiq, Rayya A; Srivathsan, Komandoor

    2016-08-15

    Cardiac resynchronization therapy (CRT) reduces ventricular arrhythmia (VA) burden in some patients with heart failure, but its effect after left ventricular assist device (LVAD) implantation is unknown. We compared VA burden in patients with CRT devices in situ who underwent LVAD implantation and continued CRT (n = 39) to those who had CRT turned off before discharge (n = 26). Implantable cardioverter-defibrillator (ICD) shocks were significantly reduced in patients with continued CRT (1.5 ± 2.7 shocks per patient vs 5.5 ± 9.3 with CRT off, p = 0.014). There was a nonsignificant reduction in cumulative VA episodes per patient with CRT continued at discharge (42 ± 105 VA per patient vs 82 ± 198 with CRT off, p = 0.29). On-treatment analysis by whether CRT was on or off identified a significantly lower burden of VA (17 ± 1 per patient-year CRT on vs 37 ± 1 per patient-year CRT off, p <0.0001) and ICD shocks (1.2 ± 0.3 per patient-year CRT on vs 1.7 ± 0.3 per patient-year CRT off, p = 0.018). In conclusion, continued CRT is associated with significantly reduced ICD shocks and VA burden after LVAD implantation. PMID:27328958

  1. A new automatic synchronizer

    SciTech Connect

    Malm, C.F.

    1995-12-31

    A phase lock loop automatic synchronizer, PLLS, matches generator speed starting from dead stop to bus frequency, and then locks the phase difference at zero, thereby maintaining zero slip frequency while the generator breaker is being closed to the bus. The significant difference between the PLLS and a conventional automatic synchronizer is that there is no slip frequency difference between generator and bus. The PLL synchronizer is most advantageous when the penstock pressure fluctuates the grid frequency fluctuates, or both. The PLL synchronizer is relatively inexpensive. Hydroplants with multiple units can economically be equipped with a synchronizer for each unit.

  2. 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.

  3. 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.

  4. Quantitative Assessment of Orbital Implant Position – A Proof of Concept

    PubMed Central

    Schreurs, Ruud; Dubois, Leander; Becking, Alfred G.; Maal, Thomas J. J.

    2016-01-01

    Introduction In orbital reconstruction, the optimal location of a predefined implant can be planned preoperatively. Surgical results can be assessed intraoperatively or postoperatively. A novel method for quantifying orbital implant position is introduced. The method measures predictability of implant placement: transformation parameters between planned and resulting implant position are quantified. Methods The method was tested on 3 human specimen heads. Computed Tomography scans were acquired at baseline with intact orbits (t0), after creation of the defect (t1) and postoperatively after reconstruction of the defect using a preformed implant (t2). Prior to reconstruction, the optimal implant position was planned on the t0 and t1 scans. Postoperatively, the planned and realized implant position were compared. The t0 and t2 scans were fused using iPlan software and the resulting implant was segmented in the fused t2 scan. An implant reference frame was created (Orbital Implant Positioning Frame); the planned implant was transformed to the reference position using an Iterative Closest Point approach. The segmentation of the resulting implant was also registered on the reference position, yielding rotational (pitch, yaw, roll) as well as translational parameters of implant position. Results Measurement with the Orbital Implant Positioning Frame proved feasible on all three specimen. The positional outcome provided more thorough and accurate insight in resulting implant position than could be gathered from distance measurements alone. Observer-related errors were abolished from the process, since the method is largely automatic. Conclusion A novel method of quantifying surgical outcome in orbital reconstructive surgery was presented. The presented Orbital Implant Positioning Frame assessed all parameters involved in implant displacement. The method proved to be viable on three human specimen heads. Clinically, the method could provide direct feedback intraoperatively

  5. Automatic measuring of quality criteria for heart valves

    NASA Astrophysics Data System (ADS)

    Condurache, Alexandru Paul; Hahn, Tobias; Hofmann, Ulrich G.; Scharfschwerdt, Michael; Misfeld, Martin; Aach, Til

    2007-03-01

    Patients suffering from a heart valve deficiency are often treated by replacing the valve with an artificial or biological implant. In case of biological implants, the use of porcine heart valves is common. Quality assessment and inspection methods are mandatory to supply the patients (and also medical research) with only the best such xenograft implants thus reducing the number of follow-up surgeries to replace worn-up valves. We describe an approach for automatic in-vitro evaluation of prosthetic heart valves in an artificial circulation system. We show how to measure the orifice area during a heart cycle to obtain an orifice curve. Different quality parameters are then estimated on such curves.

  6. Nanotechnology and dental implants.

    PubMed

    Lavenus, Sandrine; Louarn, Guy; Layrolle, Pierre

    2010-01-01

    The long-term clinical success of dental implants is related to their early osseointegration. This paper reviews the different steps of the interactions between biological fluids, cells, tissues, and surfaces of implants. Immediately following implantation, implants are in contact with proteins and platelets from blood. The differentiation of mesenchymal stem cells will then condition the peri-implant tissue healing. Direct bone-to-implant contact is desired for a biomechanical anchoring of implants to bone rather than fibrous tissue encapsulation. Surfaces properties such as chemistry and roughness play a determinant role in these biological interactions. Physicochemical features in the nanometer range may ultimately control the adsorption of proteins as well as the adhesion and differentiation of cells. Nanotechnologies are increasingly used for surface modifications of dental implants. Another approach to enhance osseointegration is the application of thin calcium phosphate (CaP) coatings. Bioactive CaP nanocrystals deposited on titanium implants are resorbable and stimulate bone apposition and healing. Future nanometer-controlled surfaces may ultimately direct the nature of peri-implant tissues and improve their clinical success rate.

  7. Nanotechnology and Dental Implants

    PubMed Central

    Lavenus, Sandrine; Louarn, Guy; Layrolle, Pierre

    2010-01-01

    The long-term clinical success of dental implants is related to their early osseointegration. This paper reviews the different steps of the interactions between biological fluids, cells, tissues, and surfaces of implants. Immediately following implantation, implants are in contact with proteins and platelets from blood. The differentiation of mesenchymal stem cells will then condition the peri-implant tissue healing. Direct bone-to-implant contact is desired for a biomechanical anchoring of implants to bone rather than fibrous tissue encapsulation. Surfaces properties such as chemistry and roughness play a determinant role in these biological interactions. Physicochemical features in the nanometer range may ultimately control the adsorption of proteins as well as the adhesion and differentiation of cells. Nanotechnologies are increasingly used for surface modifications of dental implants. Another approach to enhance osseointegration is the application of thin calcium phosphate (CaP) coatings. Bioactive CaP nanocrystals deposited on titanium implants are resorbable and stimulate bone apposition and healing. Future nanometer-controlled surfaces may ultimately direct the nature of peri-implant tissues and improve their clinical success rate. PMID:21253543

  8. Implicit active contours for automatic brachytherapy seed segmentation in fluoroscopy

    NASA Astrophysics Data System (ADS)

    Moult, Eric; Burdette, Clif; Song, Danny; Fichtinger, Gabor; Fallavollita, Pascal

    2012-02-01

    Motivation: In prostate brachytherapy, intra-operative dosimetry would be ideal to allow for rapid evaluation of the implant quality while the patient is still in the treatment position. Such a mechanism, however, requires 3-D visualization of the currently deposited seeds relative to the prostate. Thus, accurate, robust, and fully-automatic seed segmentation is of critical importance in achieving intra-operative dosimetry. Methodology: Implanted brachytherapy seeds are segmented by utilizing a region-based implicit active contour approach. Overlapping seed clusters are then resolved using a simple yet effective declustering technique. Results: Ground-truth seed coordinates were obtained via a published segmentation technique. A total of 248 clinical C-arm images from 16 patients were used to validate the proposed algorithm resulting in a 98.4% automatic detection rate with a corresponding 2.5% false-positive rate. The overall mean centroid error between the ground-truth and automatic segmentations was measured to be 0.42 pixels, while the mean centroid error for overlapping seed clusters alone was measured to be 0.67 pixels. Conclusion: Based on clinical data evaluation and validation, robust, accurate, and fully-automatic brachytherapy seed segmentation can be achieved through the implicit active contour framework and subsequent seed declustering method.

  9. Cardiac microstructure: implications for electrical propagation and defibrillation in the heart.

    PubMed

    Hooks, Darren A; Tomlinson, Karl A; Marsden, Scott G; LeGrice, Ian J; Smaill, Bruce H; Pullan, Andrew J; Hunter, Peter J

    2002-08-23

    Our understanding of the electrophysiological properties of the heart is incomplete. We have investigated two issues that are fundamental to advancing that understanding. First, there has been widespread debate over the mechanisms by which an externally applied shock can influence a sufficient volume of heart tissue to terminate cardiac fibrillation. Second, it has been uncertain whether cardiac tissue should be viewed as an electrically orthotropic structure, or whether its electrical properties are, in fact, isotropic in the plane orthogonal to myofiber direction. In the present study, a computer model that incorporates a detailed three-dimensional representation of cardiac muscular architecture is used to investigate these issues. We describe a bidomain model of electrical propagation solved in a discontinuous domain that accurately represents the microstructure of a transmural block of rat left ventricle. From analysis of the model results, we conclude that (1) the laminar organization of myocytes determines unique electrical properties in three microstructurally defined directions at any point in the ventricular wall of the heart, and (2) interlaminar clefts between layers of cardiomyocytes provide a substrate for bulk activation of the ventricles during defibrillation.

  10. 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

  11. Automatic sweep circuit

    DOEpatents

    Keefe, Donald J.

    1980-01-01

    An automatically sweeping circuit for searching for an evoked response in an output signal in time with respect to a trigger input. Digital counters are used to activate a detector at precise intervals, and monitoring is repeated for statistical accuracy. If the response is not found then a different time window is examined until the signal is found.

  12. 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…

  13. Brut: Automatic bubble classifier

    NASA Astrophysics Data System (ADS)

    Beaumont, Christopher; Goodman, Alyssa; Williams, Jonathan; Kendrew, Sarah; Simpson, Robert

    2014-07-01

    Brut, written in Python, identifies bubbles in infrared images of the Galactic midplane; it uses a database of known bubbles from the Milky Way Project and Spitzer images to build an automatic bubble classifier. The classifier is based on the Random Forest algorithm, and uses the WiseRF implementation of this algorithm.

  14. 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.

  15. Automatic finite element generators

    NASA Technical Reports Server (NTRS)

    Wang, P. S.

    1984-01-01

    The design and implementation of a software system for generating finite elements and related computations are described. Exact symbolic computational techniques are employed to derive strain-displacement matrices and element stiffness matrices. Methods for dealing with the excessive growth of symbolic expressions are discussed. Automatic FORTRAN code generation is described with emphasis on improving the efficiency of the resultant code.

  16. Reactor component automatic grapple

    SciTech Connect

    Greenaway, P.R.

    1982-12-07

    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.

  17. 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.

  18. Automatic Data Processing Glossary.

    ERIC Educational Resources Information Center

    Bureau of the Budget, Washington, DC.

    The technology of the automatic information processing field has progressed dramatically in the past few years and has created a problem in common term usage. As a solution, "Datamation" Magazine offers this glossary which was compiled by the U.S. Bureau of the Budget as an official reference. The terms appear in a single alphabetic sequence,…

  19. AUTOmatic Message PACKing Facility

    2004-07-01

    AUTOPACK is a library that provides several useful features for programs using the Message Passing Interface (MPI). Features included are: 1. automatic message packing facility 2. management of send and receive requests. 3. management of message buffer memory. 4. determination of the number of anticipated messages from a set of arbitrary sends, and 5. deterministic message delivery for testing purposes.

  20. Implants in adolescents

    PubMed Central

    Shah, Rohit A.; Mitra, Dipika K.; Rodrigues, Silvia V.; Pathare, Pragalbha N.; Podar, Rajesh S.; Vijayakar, Harshad N.

    2013-01-01

    Implants have gained tremendous popularity as a treatment modality for replacement of missing teeth in adults. There is extensive research present on the use of implants in adults, but there is a dearth of data available on the same in adolescents. The treatment planning and execution of implant placement in adolescents is still in its infancy. This review article is an attempt to bring together available literature. PMID:24174743

  1. Remote Monitoring of Cardiac Implantable Devices: Ontology Driven Classification of the Alerts.

    PubMed

    Rosier, Arnaud; Mabo, Philippe; Temal, Lynda; Van Hille, Pascal; Dameron, Olivier; Deleger, Louise; Grouin, Cyril; Zweigenbaum, Pierre; Jacques, Julie; Chazard, Emmanuel; Laporte, Laure; Henry, Christine; Burgun, Anita

    2016-01-01

    The number of patients that benefit from remote monitoring of cardiac implantable electronic devices, such as pacemakers and defibrillators, is growing rapidly. Consequently, the huge number of alerts that are generated and transmitted to the physicians represents a challenge to handle. We have developed a system based on a formal ontology that integrates the alert information and the patient data extracted from the electronic health record in order to better classify the importance of alerts. A pilot study was conducted on atrial fibrillation alerts. We show some examples of alert processing. The results suggest that this approach has the potential to significantly reduce the alert burden in telecardiology. The methods may be extended to other types of connected devices. PMID:27071877

  2. Reliability and Validity of the Self Efficacy Expectations and Outcome Expectations After ICD Implantation Scales

    PubMed Central

    Dougherty, Cynthia M.; Johnston, Sandra K.; Thompson, Elaine Adams

    2009-01-01

    The purpose of this study was to assess the reliability and validity characteristics of two new scales that measure self-efficacy expectations (SE-ICD) and outcome expectations (OE-ICD) in survivors (n=168) of sudden cardiac arrest (SCA), all of whom received an implantable cardioverter defibrillator (ICD). Cronbach's alpha reliability demonstrated good internal consistency (SE-ICD α = 0.93 and OE-ICD α = 0.81). Correlations with other self-efficacy instruments (general self-efficacy and social self-efficacy) were consistently high. The instruments were responsive to change across time with effect sizes of 0.46 for SE-ICD, and 0.26 for OE-ICD. These reliable, valid, and responsive instruments for measurement of self-efficacy expectations and outcome expectations after an ICD can be used in research and clinical settings. PMID:17693214

  3. Fully automatic telemetry data processor

    NASA Technical Reports Server (NTRS)

    Cox, F. B.; Keipert, F. A.; Lee, R. C.

    1968-01-01

    Satellite Telemetry Automatic Reduction System /STARS 2/, a fully automatic computer-controlled telemetry data processor, maximizes data recovery, reduces turnaround time, increases flexibility, and improves operational efficiency. The system incorporates a CDC 3200 computer as its central element.

  4. Automatism and driving offences.

    PubMed

    Rumbold, John

    2013-10-01

    Automatism is a rarely used defence, but it is particularly used for driving offences because many are strict liability offences. Medical evidence is almost always crucial to argue the defence, and it is important to understand the bars that limit the use of automatism so that the important medical issues can be identified. The issue of prior fault is an important public safeguard to ensure that reasonable precautions are taken to prevent accidents. The total loss of control definition is more problematic, especially with disorders of more gradual onset like hypoglycaemic episodes. In these cases the alternative of 'effective loss of control' would be fairer. This article explores several cases, how the criteria were applied to each, and the types of medical assessment required. PMID:24112330

  5. 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.

  6. Automatism and driving offences.

    PubMed

    Rumbold, John

    2013-10-01

    Automatism is a rarely used defence, but it is particularly used for driving offences because many are strict liability offences. Medical evidence is almost always crucial to argue the defence, and it is important to understand the bars that limit the use of automatism so that the important medical issues can be identified. The issue of prior fault is an important public safeguard to ensure that reasonable precautions are taken to prevent accidents. The total loss of control definition is more problematic, especially with disorders of more gradual onset like hypoglycaemic episodes. In these cases the alternative of 'effective loss of control' would be fairer. This article explores several cases, how the criteria were applied to each, and the types of medical assessment required.

  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 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.

  9. 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.

  10. Automatic volume calibration system

    SciTech Connect

    Gates, A.J.; Aaron, C.C.

    1985-05-06

    The Automatic Volume Calibration System presently consists of three independent volume-measurement subsystems and can possibly be expanded to five subsystems. When completed, the system will manually or automatically perform the sequence of valve-control and data-acquisition operations required to measure given volumes. An LSI-11 minicomputer controls the vacuum and pressure sources and controls solenoid control valves to open and close various volumes. The input data are obtained from numerous displacement, temperature, and pressure sensors read by the LSI-11. The LSI-11 calculates the unknown volume from the data acquired during the sequence of valve operations. The results, based on the Ideal Gas Law, also provide information for feedback and control. This paper describes the volume calibration system, its subsystems, and the integration of the various instrumentation used in the system's design and development. 11 refs., 13 figs., 4 tabs.

  11. Automatic Skin Color Beautification

    NASA Astrophysics Data System (ADS)

    Chen, Chih-Wei; Huang, Da-Yuan; Fuh, Chiou-Shann

    In this paper, we propose an automatic skin beautification framework based on color-temperature-insensitive skin-color detection. To polish selected skin region, we apply bilateral filter to smooth the facial flaw. Last, we use Poisson image cloning to integrate the beautified parts into the original input. Experimental results show that the proposed method can be applied in varied light source environment. In addition, this method can naturally beautify the portrait skin.

  12. Double Sequential External Defibrillation in Out-of-Hospital Refractory Ventricular Fibrillation: A Report of Ten Cases.

    PubMed

    Cabañas, José G; Myers, J Brent; Williams, Jefferson G; De Maio, Valerie J; Bachman, Michael W

    2015-01-01

    Abstract Background. Ventricular fibrillation (VF) is considered the out-of-hospital cardiac arrest (OOHCA) rhythm with the highest likelihood of neurologically intact survival. Unfortunately, there are occasions when VF does not respond to standard defibrillatory shocks. Current American Heart Association (AHA) guidelines acknowledge that the data are insufficient in determining the optimal pad placement, waveform, or energy level that produce the best conversion rates from OOHCA with VF. Objective. To describe a technique of double sequential external defibrillation (DSED) for cases of refractory VF (RVF) during OOHCA resuscitation. Methods. A retrospective case series was performed in an urban/suburban emergency medical services (EMS) system with advanced life support care and a population of 900,000. Included were all adult OOHCAs having RVF during resuscitation efforts by EMS providers. RVF was defined as persistent VF following at least 5 unsuccessful single shocks, epinephrine administration, and a dose of antiarrhythmic medication. Once the patient was in RVF, EMS personnel applied a second set of pads and utilized a second defibrillator for single defibrillation with the new monitor/pad placement. If VF continued, EMS personnel then utilized the original and second monitor/defibrillator charged to maximum energy, and shocks were delivered from both machines simultaneously. Data were collected from electronic dispatch and patient care reports for descriptive analysis. Results. From 01/07/2008 to 12/31/2010, a total of 10 patients were treated with DSED. The median age was 76.5 (IQR: 65-82), with median resuscitation time of 51minutes (IQR: 45-62). The median number of single shocks was 6.5 (IQR: 6-11), with a median of 2 (IQR: 1-3) DSED shocks delivered. VF broke after DSED in 7 cases (70%). Only 3 patients (30%) had ROSC in the field, and none survived to discharge. Conclusion. This case series demonstrates that DSED may be a feasible technique as part of

  13. 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.

  14. 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.

  15. Automatic payload deployment system

    NASA Astrophysics Data System (ADS)

    Pezeshkian, Narek; Nguyen, Hoa G.; Burmeister, Aaron; Holz, Kevin; Hart, Abraham

    2010-04-01

    The ability to precisely emplace stand-alone payloads in hostile territory has long been on the wish list of US warfighters. This type of activity is one of the main functions of special operation forces, often conducted at great danger. Such risk can be mitigated by transitioning the manual placement of payloads over to an automated placement mechanism by the use of the Automatic Payload Deployment System (APDS). Based on the Automatically Deployed Communication Relays (ADCR) system, which provides non-line-of-sight operation for unmanned ground vehicles by automatically dropping radio relays when needed, the APDS takes this concept a step further and allows for the delivery of a mixed variety of payloads. For example, payloads equipped with a camera and gas sensor in addition to a radio repeater, can be deployed in support of rescue operations of trapped miners. Battlefield applications may include delivering food, ammunition, and medical supplies to the warfighter. Covert operations may require the unmanned emplacement of a network of sensors for human-presence detection, before undertaking the mission. The APDS is well suited for these tasks. Demonstrations have been conducted using an iRobot PackBot EOD in delivering a variety of payloads, for which the performance and results will be discussed in this paper.

  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. 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

  18. Preventing Sudden Cardiac Death: Automated External Defibrillators in Ohio High Schools

    PubMed Central

    Lear, Aaron; Hoang, Minh-Ha; Zyzanski, Stephen J.

    2015-01-01

    Context Ohio passed legislation in 2004 for optional public funding of automated external defibrillators (AEDs) in all Ohio high schools. Objective To report occurrences of sudden cardiac arrest in which AEDs were used in Ohio high schools and to evaluate the adherence of Ohio high schools with AEDs to state law and published guidelines on AEDs and emergency action plans (EAPs) in schools. Design Cross-sectional survey. Setting Web-based survey. Patients or Other Participants A total of 264 of 827 schools that were members of the Ohio High School Athletic Association. Main Outcome Measure(s) We surveyed schools on AED use, AED maintenance, and EAPs. Results Twenty-five episodes of AED deployment at 22 schools over an 11-year period were reported; 8 (32%) involved students and 17 (68%) involved adults. The reported survival rate was 60% (n = 15). Most events (n = 20, 80%) in both students and adults occurred at or near athletic facilities. The annual use rate of AEDs was 0.7%. Fifty-three percent (n = 140) of schools reported having an EAP in place for episodes of cardiac arrest. Of the schools with EAPs, 57% (n = 80) reported having rehearsed them. Conclusions Our data supported the placement of AEDs in high schools given the frequency of use for sudden cardiac arrest and the survival rate reported. They also suggested the need for increased awareness of recommendations for EAPs and the need to formulate and practice EAPs. School EAPs should emphasize planning for events in the vicinity of athletic facilities. PMID:26381367

  19. Cardiac Response to Low Energy Field Pacing Challenges the Standard Theory of Defibrillation

    PubMed Central

    Caldwell, Bryan J.; Trew, Mark L.; Pertsov, Arkady M.

    2015-01-01

    Background The electrical response of myocardial tissue to periodic field stimuli has attracted significant attention as the basis for low-energy anti-fibrillation pacing (LEAP), potentially more effective than traditional single high-energy shocks. In conventional models, an electric field produces a highly non-uniform response of the myocardial wall, with discrete excitations, or “hot spots” (HS), occurring at cathodal tissue surfaces or large coronary vessels. We test this prediction using novel 3D tomographic optical imaging. Methods and Results Experiments were performed in isolated coronary perfused pig ventricular wall preparations stained with near-infrared voltage-sensitive fluorescent dye DI-4-ANBDQBS. The 3D coordinates of HS were determined using alternating transillumination. To relate HS formation with myocardial structures we used ultra-deep confocal imaging (interrogation depths >4 mm). The peak HS distribution is located deep inside the heart wall and the depth is not significantly affected by field polarity. We did not observe the strong co-localization of HS with major coronary vessels anticipated from theory. Yet, we observed considerable lateral displacement of HS with field polarity reversal. Models that deemphasized lateral intracellular coupling and accounted for resistive heterogeneity in the extracellular space showed similar HS distributions to the experimental observations. Conclusions The HS distributions within the myocardial wall and the significant lateral displacements with field polarity reversal are inconsistent with standard theories of defibrillation. Extended theories based around enhanced descriptions of cellular scale electrical mechanisms may be necessary. The considerable lateral displacement of HS with field polarity reversal supports the hypothesis of biphasic stimuli in LEAP being advantageous. PMID:25772543

  20. Machine Learning Techniques for the Detection of Shockable Rhythms in Automated External Defibrillators.

    PubMed

    Figuera, Carlos; 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

  1. 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. PMID:27436999

  2. 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

  3. 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

  4. Mobility implants: a review.

    PubMed

    Danz, W

    1990-01-01

    We present a brief review of mobility implants, their contribution, and the experiences derived after almost 40 years since the new concepts of full mobility implants were introduced. In early 1940, experiments with a new material for the making of plastic artificial eyes was also being considered for the making of orbital implants. Methyl-methacrylate (MMA) had proven inert and satisfactory for dental products. The Surgeon Generals office of the Armed Services encouraged further research and experimental work in the development of plastic eyes. The success of the new material sponsored the beginning of great expansion with new concepts for orbital implants. Through a period of more than a decade, the design and types of implants went through three stages. First, the buried implant was introduced, then the exposed integrated followed, and the buried integrated subsequently followed. The path of progress was not smooth. Theoretically correct designs and surgical procedures met unexpected practical difficulties for the ophthalmic surgeon, the patient, and the eye maker. Surgical and technical efforts were carefully reviewed to eliminate the problems encountered, only to have further unforeseen complications arise. Infections, extrusions, and migration of the implant were not uncommon. The exposed integrated implant was eventually abandoned. However, there were some extraordinary successes of mobility. A new era introduced fully buried mobility implants that were more successful. However, this procedure also produced some problems, causing infection (or allergy), extrusion, and migration. Tantalum mesh and gauze gave great promise with the inception of their use. Orbital tissue grew into the material in an astonishing way, making it possible to secure the extraocular muscles and tenons.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. 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.

  6. 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.

  7. 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.

  8. Automatic level control circuit

    NASA Technical Reports Server (NTRS)

    Toole, P. C.; Mccarthy, D. M. (Inventor)

    1983-01-01

    An automatic level control circuit for an operational amplifier for minimizing spikes or instantaneous gain of the amplifier at a low period wherein no signal is received on the input is provided. The apparatus includes a multibranch circuit which is connected between an output terminal and a feedback terminal. A pair of zener diodes are connected back to back in series with a capacitor provided in one of the branches. A pair of voltage dividing resistors are connected in another of the branches and a second capacitor is provided in the remaining branch of controlling the high frequency oscillations of the operational amplifier.

  9. Reflections on Rodent Implantation.

    PubMed

    Cha, Jeeyeon M; Dey, Sudhansu K

    2015-01-01

    Embryo implantation is a complex process involving endocrine, paracrine, autocrine, and juxtacrine modulators that span cell-cell and cell-matrix interactions. The quality of implantation is predictive for pregnancy success. Earlier observational studies formed the basis for genetic and molecular approaches that ensued with emerging technological advances. However, the precise sequence and details of the molecular interactions involved have yet to be defined. This review reflects briefly on aspects of our current understanding of rodent implantation as a tribute to Roger Short's lifelong contributions to the field of reproductive physiology. PMID:26450495

  10. Spectroscopy of implants

    NASA Astrophysics Data System (ADS)

    Afanasyeva, Natalia I.

    1994-01-01

    The spectral criteria of selection of soft intraocular lens (IOL) implants of long service in an organism have been defined for ophthalmology. The analysis of Fourier Transform Infrared (FTIR) spectra provides the required and sufficient level of material polymerization for manufacturing non-toxic lenses for the eye. The spectral limits for determining the biocompatibility of samples can be related to the intensity ratio of two bands only in the FTIR spectra of siloxane. Siloxane-poly(urethane) block copolymers and other materials for implants have been studied. Passivated surfaces of implants have been obtained and registered by methods of Fourier Transform Spectroscopy.

  11. Efficacy of bystander cardiopulmonary resuscitation and out-of-hospital automated external defibrillation as life-saving therapy in commotio cordis.

    PubMed

    Salib, Erik A; Cyran, Stephen E; Cilley, Robert E; Maron, Barry J; Thomas, Neal J

    2005-12-01

    We report a child who sustained commotio cordis after being struck by a baseball, and offer documentation of the advantages of having readily available access to bystander cardiopulmonary resuscitation (CPR) and an automated external defibrillator (AED). We suggest that communities and school districts reexamine the need for accessible AEDs and CPR-trained coaches at organized sporting events for children.

  12. The evolution of embryo implantation.

    PubMed

    McGowen, Michael R; Erez, Offer; Romero, Roberto; Wildman, Derek E

    2014-01-01

    Embryo implantation varies widely in placental mammals. We review this variation in mammals with a special focus on two features: the depth of implantation and embryonic diapause. We discuss the two major types of implantation depth, superficial and interstitial, and map this character on a well-resolved molecular phylogenetic tree of placental mammals. We infer that relatively deep interstitial implantation has independently evolved at least eight times within placental mammals. Moreover, the superficial type of implantation represents the ancestral state for placental mammals. In addition, we review the genes involved in various phases of implantation, and suggest a future direction in investigating the molecular evolution of implantation-related genes. PMID:25023681

  13. Biofibre hair implant: what is new, what is true?

    PubMed

    Tchernev, G; Sheta, M; Rahoui, M; Chokoeva, A A; Wollina, U; Maximov, G K; Patterson, J W; Fioranelli, M; Roccia, M G; Ananiev, J; Lotti, T

    2016-01-01

    Ensuring the safety of hair implant fibers is essential. At the same time, good aesthetic quality and durability should also be considered in order to maintain expected result over the years. The main features required are biocompatibility, resistance to traction, absence of capillarity, resistance to physical-chemical stress, and low tissue trauma, in addition to good aesthetics. Biofibre® medical hair prosthetic fibers meet all the biocompatibility and safety requirements established by international standards for medical devices. They are available in 13 colors, with different lengths (15, 30 or 45 cm) and various shapes (straight, wavy, curly and afro). Biofibre® hair implants are indicated for diffuse hair loss or hair thinning in cases where an immediate aesthetic result is required, when patients request minor surgery without hospitalization, both for male and female patients, in combination with other hair restoration techniques to improve the final aesthetic result, to correct scars or scalp burns and in cases of poor donor areas. Biofibre® Hair Implant is in fact a minor surgery technique, performed under local anesthesia by either a manual implanter or an automatic machine which enables an immediate aesthetic result and the desired quantity of hair without pain or hospitalization. Clinical and histological studies have demonstrated that Biofibre® hair Implants are safe and well tolerated by patients and can be totally reversible if the need arises. This technique requires good after-care, periodical check-ups and yearly implant re-touches to maintain the best cosmetic result.

  14. 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.

  15. 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.

  16. Automatic temperature control

    SciTech Connect

    Sheridan, J.P.

    1986-07-22

    An automatic temperature control system is described for maintaining a preset temperature in an enclosed space in a building, comprising: heating and cooling means for conditioning the air in the enclosed space to maintain the preset temperature; exterior thermostat means outside the building for sensing ambient exterior temperature levels; interior thermostat means in the enclosed space, preset to the preset temperature to be maintained and connected with the heating and cooling means to energize the means for heating or cooling, as appropriate, when the preset temperature is reached; means defining a heat sink containing a volume of air heated by solar radiation, the volume of the heat sink being such that the temperature level therein is not affected by minor or temporary ambient temperature fluctuations; and heat sink thermostat means in the heat sink sensing the temperature in the heat sink, the heat sink thermostat means being connected in tandem with the exterior thermostat means and operative with the exterior thermostat means to switch the interior thermostat means to either a first readiness state for heating or a second readiness state for cooling, depending upon which mode is indicated by both the exterior and heat sink thermostat means, whereby the system automatically switches between heating and cooling, as required, in response to a comparison of exterior and heat sink temperatures.

  17. Peri-Implant Diseases

    MedlinePlus

    ... and flossing and regular check-ups from a dental professional. Other risks factors for developing peri-implant disease include previous periodontal disease diagnosis, poor plaque control, smoking , and diabetes . It is essential to routinely ...

  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. Risks of Breast Implants

    MedlinePlus

    ... larger and longer than these conducted so far. Breastfeeding Some women who undergo breast augmentation can successfully ... breast implant silicone shell into breast milk during breastfeeding. Although there are currently no established methods for ...

  20. Ion implantation at elevated temperatures

    SciTech Connect

    Lam, N.Q.; Leaf, G.K.

    1985-11-01

    A kinetic model has been developed to investigate the synergistic effects of radiation-enhanced diffusion, radiation-induced segregation and preferential sputtering on the spatial redistribution of implanted solutes during implantation at elevated temperatures. Sample calculations were performed for Al and Si ions implanted into Ni. With the present model, the influence of various implantation parameters on the evolution of implant concentration profiles could be examined in detail.