The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform
Peter J. Wijkstra - One of the best experts on this subject based on the ideXlab platform.
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Diaphragm Pacemaker: alternative for chronic ventilatory support
Nederlands Tijdschrift voor Geneeskunde, 2020Co-Authors: Anda Hazenberg, Sijbrand S Hofker, Jellie Nieuwenhuis, Huib A. M. Kerstjens, Peter J. WijkstraAbstract:: Currently, more than 2200 patients in the Netherlands receive chronic ventilatory support. In the majority of patients this leads to increased survival without any complications. Nevertheless, in case of ventilatory support via a mask, problems such as skin irritation, leakage and claustrophobia can occur. In case of tracheostomy, it can lead to increased pulmonary secretion. Diaphragm pacing with an External Pacemaker might be an attractive alternative to prevent these symptoms as it can replace ventilatory support by mask or tracheostomy. Current indications are patients with spinal cord injury or with congenital central hypoventilation syndrome who are chronically respiratory insufficient. In our experience, patients can be completely or partially weaned from mechanical ventilation when using the diaphragm pacer. In the Netherlands, the technique is only performed at the University Medical Center Groningen.
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Diaphragm Pacemaker: alternative for long-term ventilatory support; 5 years later
Nederlands Tijdschrift voor Geneeskunde, 2019Co-Authors: Anda Hazenberg, Sijbrand S Hofker, Jellie Nieuwenhuis, Huib A. M. Kerstjens, Peter J. WijkstraAbstract:: Currently, more than 3000 patients in the Netherlands receive long-term ventilatory support. In the majority of patients, long-term ventilatory support leads to increased survival without any complications. Diaphragm pacing with an External Pacemaker (diaphragm pacing system, DPS) seems an attractive alternative for long-term ventilatory support by mask or tracheostomy. Scientific research has since shown that DPS is effective in patients with high cervical paraplegia. In addition, patients with congenital central hypoventilation syndrome are also eligible for DPS. Patients with diaphragm paralysis are a new group of patients who may be eligible for DPS. Two European studies have shown that DPS should not be used in patients with amyotrophic lateral sclerosis. In our experience, patients are no longer completely dependent on a ventilator or may even be able to discontinue using one if the procedure was successful. In the Netherlands, as far as we know, the technique is only used at the University Medical Center Groningen.
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DiafragmaPacemaker: alternatief voor chronische beademing
Nederlands Tijdschrift voor Geneeskunde, 2019Co-Authors: Anda Hazenberg, Sijbrand S Hofker, Jellie Nieuwenhuis, Huib A. M. Kerstjens, Peter J. WijkstraAbstract:Currently, more than 3000 patients in the Netherlands receive long-term ventilatory support. In the majority of patients, long-term ventilatory support leads to increased survival without any complications. Diaphragm pacing with an External Pacemaker (diaphragm pacing system, DPS) seems an attractive alternative for long-term ventilatory support by mask or tracheostomy. Scientific research has since shown that DPS is effective in patients with high cervical paraplegia. In addition, patients with congenital central hypoventilation syndrome are also eligible for DPS. Patients with diaphragm paralysis are a new group of patients who may be eligible for DPS. Two European studies have shown that DPS should not be used in patients with amyotrophic lateral sclerosis. In our experience, patients are no longer completely dependent on a ventilator or may even be able to discontinue using one if the procedure was successful. In the Netherlands, as far as we know, the technique is only used at the University Medical Center Groningen.
Carl G Schaanning - One of the best experts on this subject based on the ideXlab platform.
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variation in pacing threshold a study in patients with External Pacemaker and unipolar endocardial electrode
Acta Medica Scandinavica, 2009Co-Authors: Helge Grendahl, Carl G SchaanningAbstract:Abstract. The pacing threshold has been examined in patients with endocardial Pacemaker electrode and External Pacemaker. A mean increase in pacing threshold was observed in the first 7 to 14 days after insertion of the electrode, from 1.3 volt at the time of insertion to 2.5 volts after 7 days and 2.8 volts after 14 days. In some patients an initial and transitory decrease was found in the first few days. Great individual variations were seen. Because of these variations it is, in our opinion, necessary to check the threshold value in patients with myocardial infarction by daily measurements to adjust the Pacemaker output at the lowest possible level. Significant variations during the day, and after meals, sleeping or physical activity, as reported by others, were not found.
Laurent Storme - One of the best experts on this subject based on the ideXlab platform.
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Electro-stimulation in preterm neonates with congenital auriculo-ventricular block. Report of three cases
European Journal of Pediatrics, 2004Co-Authors: Thameur Rakza, Armelle Delapintiere, Eric Magnenant, Pierre Lequien, Guy Vaksmann, Nahida Rifai, Michel Bonnevalle, Laurent StormeAbstract:Congenital auriculo-ventricular blocks (CAVB) are usually linked to maternal auto-immune diseases and their management remains controversial. We report three cases of CAVB in preterm newborns managed using electro-stimulation with an External, followed by an internal Pacemaker. Results and long-term follow-up were satisfactory in all three children. Conclusion: The transitory placement of an External Pacemaker seems necessary in low birth weight infants in order to allow weight gain and therefore the insertion of a permanent Pacemaker. The prognosis seems good but a regular echocardiographic surveillance is of great importance in order to detect the onset of cardiac failure secondary to dilated cardiomyopathy.
A.w. Frey - One of the best experts on this subject based on the ideXlab platform.
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Variability of arterial blood pressure and heart rate evaluated by fixed rate atrial pacing
Computers in Cardiology 1995, 1995Co-Authors: J. Barnstedt, A. Stellmacher, M. Dambacher, J.h. Baumert, A.w. FreyAbstract:Variability of arterial blood pressure (BPV) and heart rate (HRV) were investigated in 26 patients shortly after CABG surgery under two conditions: During the first recording patients had sinus rhythm of 65 to 88 beats per minute; after that the atrium was stimulated at 91 to 115 beats per minute with an External Pacemaker. HRV and BPV were determined by discrete Fourier analysis of low frequency (LF) and high frequency (HF) spectral power. While HRV decreases in LF to
Smiljana Jelić - One of the best experts on this subject based on the ideXlab platform.
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STABILITY OF A GENERAL DELAY DIFFERENTIAL MODEL OF THE HYPOTHALAMO-PITUITARY-ADRENOCORTICAL SYSTEM
International Journal of Bifurcation and Chaos, 2020Co-Authors: Danka Savic, Smiljana Jelić, Nikola BurićAbstract:Most of the systems in an organism (human included) function in a regular daily rhythm. Hypothalamo-pituitary-adrenocortical (HPA) axis, although mostly known for its role in stress response, probably has a role in conveying rhythmic signals from the major Pacemaker, suprachiazmatic nucleus (SCN), to the periphery. A general qualitative nonphenomenological mathematical model of the HPA axis is constructed and its dynamics is examined using linear stability analysis and Roushe's theorem. The results show that this system is asymptotically stable, i.e. it does not generate circadian oscillations, but only responds to the External Pacemaker.
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A theoretical study of hypothalamo-pituitary-adrenocortical axis dynamics.
Annals of the New York Academy of Sciences, 2020Co-Authors: Danka Savic, Smiljana JelićAbstract:: Does the hypothalamo-pituitary-adrenocortical (HPA) axis itself generate oscillations? The affirmative answer to this question is commonly assumed, because a regular daily rhythm of its hormones is observed. We offer another plausible explanation of the origin of this pattern: HPA just responds to an External Pacemaker. A qualitative mathematical model is constructed wherein all the terms in the equations are physicochemically interpretable. Linear stability analysis shows that this system does not generate oscillations. Computer simulation yields oscillations that are the system's response to an External pulsing activator, implying that the observed pattern does not have to be an intrinsic property of this system.
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A mathematical model of the hypothalamo-pituitary-adrenocortical system and its stability analysis
Chaos Solitons & Fractals, 2005Co-Authors: Danka Savic, Smiljana JelićAbstract:Abstract It is commonly assumed that the hypothalamo-pituitary-adrenocortical (HPA) axis generates oscillations, because a regular daily rhythm of its component hormones is observed. We offer another plausible explanation of the origin of its circadian oscillations: HPA just responds to an independent External Pacemaker (from the suprachiazmatic nucleus, SCN). Five versions (with and without time delay) of a qualitative non-phenomenological mathematical model of the HPA axis as a feedback mechanism are constructed wherein all the terms in the equations are introduced according to the rules of chemical kinetics, i.e. are physicochemically interpretable. The dynamics of the HPA axis model was examined using linear stability analysis. The results show stability of this system, meaning that it does not generate diurnal oscillations. Computer simulation based on this model shows oscillations that are system’s response to an External pulsing activator (SCN) implying that the observed time-periodic pattern does not have to be an intrinsic property of the HPA axis.
