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Cardiac Pacemaker - Crossref

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Last Updated: 10 January 2023

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CONDUCTION DISORDERS AND PERMANENT CARDIAC PACEMAKER AFTER TRANSCATHETER AORTIC IMPLANTATION - AN UPDATE OVERVIEW

A more viable alternative to reducing morbidity and mortality by minimally invasive transcatheter aortic valve implantation may be a viable alternative. Catheter aortic prosthesis implantation is a safe option for patients with high surgical risk and severe aortic stenosis. According to the study findings, the need for a pacemaker after endovascular therapy is neither inevitable nor easily predicted by known risk factors. Forthcoming studies must be required to confirm the new algorithm and determine the role of EP studies, ambulatory continuous electrocardiogram monitoring, and preventive pacemaker in the treatment of conduction disorders in patients undergoing transcatheter aortic valve replacement.

Source link: https://doi.org/10.29121/granthaalayah.v9.i8.2021.4110


Towards the Emulation of the Cardiac Conduction System for Pacemaker Validation

Abnormalities in the center of the body's electrical activity can be treated with a cardiac pacemaker. Many high-fidelity heart models have been created, but they are too computationally complex to be simulated in real-time. The Heart models, which were specifically created for the purpose of timingmaker logic testing, are too general to be useful for pacemaker validations. This paper discusses a more computationally effective heart model that produces realistic piecewise continuous electrical signals in the context of pacemaker experiments, as opposed to high-fidelity heart models. The heart model is made up of cardiac cells that are linked by paths. Our heart model is based on the Stony Brook cardiac cell model and the UPenn path model, and it enhances them by stabilizing the cell growth rate and capturing piecewise continuous propagation of electrical propagation. In addition, re-entrant circuits can be faithfully modelled, something only the discrete-event UPenn heart model is also able to achieve.

Source link: https://doi.org/10.1145/3134845


The eastern cardiac pacemaker surveillance center of the U. S. veterans administration

The VA Eastern Pacemaker Surveillance Center, which is a comprehensive center for pacemaker research, shares three roles. In addition, EPSC also manages the national VA Pacemaker Registry, which is home to over 20,000 patients. Using the public domain FileMan DBMS, the EPSC database is embedded in MUMPS on a PDP 11/44 mini-computer. The EPSC database, which was originally planned for multi-programmable pulse generators and dual chamber pacing, includes the expanding range of new pacing parameters.

Source link: https://doi.org/10.1145/16297.16299


A three-dimensional hybrid pacemaker electrode seamlessly integrates into engineered, functional human cardiac tissue in vitro

Abstract Pacemaker systems are a vital aid in the prevention of cardiovascular diseases. However, increasing the excitation threshold results in the encapsulation of a pacemaker electrode and an impaired energy efficiency as a result of the immune system's natural reaction to a foreign body. Implant properties such as size, mechanical flexibility, shape, and dimensionality influence the integration of the electrode into the tissue. Compared to 2D TiN electrodes, this 3D electrode had better electrical and immunological characteristics. An enhanced electrical result was shown on the fiber electrode as compared to the planar 2D electrode. There were no adverse foreign body responses after an early and late in vivo host response assessment subcutaneously, but no adverse international body response was observed. A tissue-electrode hybrid was created by embedding the 3D fiber scaffold in human cardiomyocytes, resulting in a high regenerative capacity and a low risk of fibrosis.

Source link: https://doi.org/10.1038/s41598-018-32790-8


Cardiac pacemaker channel (HCN4) inhibition and atrial arrhythmogenesis after releasing cardiac sympathetic activation

Abstract - The onset of atrial arrhythmias can be traced to cardiac pacemaker channels, according to clinical trials and experiments with ivabradine. We reviewed humans in whom acute changes in cardiac autonomic tone led to atrial arrhythmias, and we were quickly alerted to the test effects of HCN4 inhibition with ivabradine on atrial arrhythmias. Two experienced cardiac electrophysiologists and a physician, who were blinded for treatment assignment, were analyzed in the new secondary analysis with predefined endpoints before data unblinding, continuous finger blood pressure, and ECG recordings. Atrial events were markedly higher with ivabradine than with metoprolol or placebo, particularly after backwards tilting. Unlike beta-adrenoreceptor blockade, HCN4 inhibition when lowering heart rate does not shield against atrial arrhythmias in cases of experimental cardiac sympathetic stimulation. The model, in addition to providing information about HCN4's role in human arachnogenesis, may be useful in determining potential atrial pro-arrhythmic drug properties.

Source link: https://doi.org/10.1038/s41598-018-26099-9


Cardiac Pacemaker Oscillation and Its Modulation by Autonomic Transmitters

It is investigated what the mechanism of acetylcholine's inhibitory activity on pacemaker cells is. Acetylcholine's increasing outward potassium current in both amphibian and mammal, and there is now evidence that it may do so by opening up a unique acetylcholine-activated potassium channel. In the presence of an extracellular potassium buildup that inevitably contributes to the flow of outward membrane current, the Appendix provides a brief review of the experimental and theoretical basis for the method of exponential separation of outward current components.

Source link: https://doi.org/10.1242/jeb.81.1.175


Cellular and Subcellular Mechanisms of Cardiac Pacemaker Oscillations

ABSTRACT Rhythmic oscillations in heart cells' membrane potential are vital in normal cardiac rhythmmaker function as well as cardiac arrhythmias. The first mechanism, which is referred to as a surface membrane oscillator, can be represented by a control loop in which membrane potential changes lead to delayed conductance changes and vice versa. Since the surface membrane potential is a significant variable in the control loop, the oscillation can be interrupted at any time by holding the membrane potential constant with a voltage clamp. This mode of oscillation seems to be used to describe spontaneous pacemaker activity in the primary cardiac pacemaker as well as other places. The existence of the internal oscillation is shown by the presence of oscillations in membrane conductance or contractile force that persist even though the membrane potential remains stable under voltage clamp.

Source link: https://doi.org/10.1242/jeb.81.1.205


Intracellular Studies On Pacemaker and Follower Neurones in the Cardiac Ganglion of Limulus

ABSTRACT The heart of invertebrates' cardiac ganglion cells of invertebrates have been restricted mainly to decapod and stomatopod crustaceans' hearts. Several studies on following cells of crustacean cardiac ganglia are abundant, but intracellular investigations into pacemaker cells are lacking, with one exception limited to the stomatopod, Squilla's cardiac ganglion. With each heart beat, the most anterior-cells in Squilla display pacemaker potentials and fire in bursts. However, all neurones in the ganglion are electrically linked, and pacemaker work in the posterior portion of the ganglion may also be initiated. The two largest of a crab heart's posterior cells were used to produce decapod activity in a decapod heart. These two large cells were spontaneously active, but Bullock & Terzuolo found that there were no excitatory postsynaptic potentials despite no pacemaker possibilities, but Bullock & Terzuolo said there were no pacemaker potentials present, but Bullock & Terzuolo concluded that there were no excitatory postsynaptic potentials remained intact, but no excitatory postsynaptic potentials were present, but no pacemaker z The Limulus cardiac ganglion is believed to be made of many hundreds of cells. Heinbecker and Prosser investigated ganglion cell electrical conductivity. During each burst, Prosser units were only fired once per burst and other units were fired with spikes superimposed on a slow wave during each burst. One review of the activity of the ganglion's largest cells, the large pigmented unipolars, has been limited to one research. Bursey & Pax 1970 found five forms of neurones: large unipolars, bipolars, and multipolars, as well as small bipolars and multipolars.

Source link: https://doi.org/10.1242/jeb.54.3.815


Cardiac Pacemaker Cells Generate Cardiomyocytes from Fibroblasts in Long-Term Cultures

Abstract Since cardiomyocyte generation is limited, the turnover of cardiomyocytes in adult heart tissues is highly debated. Cardiomyocytes can be produced in vitro by cardiac pacemaker cells, according to We're here. The Sinoatrial node cells were isolated from adult guinea pig hearts and were cultured at very low cell densities and were isolated from adult guinea pig hearts and were cultured at relatively low cell densities. The cluster formation was hampered by prohibition of beating during culture. In addition, purified guinea pig cardiac fibroblasts produced cardiac-specific proteins in co-culture with SANCs or in a SANC-preconditioned culture medium under electrical stimulation. These findings reveal that SANCs can produce cardiomyocytes from cardiac fibroblasts by the presence of a humoral factor and electrophysiological activities, followed by intracellular Ca 2+ oscillations. This ability of SANCs to produce cardiomyocytes in the vicinity of pacemaker cells is a novel way by which cardiomyocytes turn over in the vicinity of pacemaker cells and could be exploited in the development of cardiac regenerative therapy in adult hearts.

Source link: https://doi.org/10.1038/s41598-019-51001-6


Symbiotic cardiac pacemaker

Abstract Self-powered implantable medical electronic systems that capture biomechanical energy from cardiac arrest, respiratory regulation, and blood flow are all part of a paradigm shift on the horizon. The open circuit voltage of an implantable triboelectric nanogenerator with a 55. 2 V. The energy recovered from each cardiac motion cycle is 0. 45 u03bcJ, which is higher than the recommended endocardial pacing threshold value.

Source link: https://doi.org/10.1038/s41467-019-09851-1

* Please keep in mind that all text is summarized by machine, we do not bear any responsibility, and you should always check original source before taking any actions

* Please keep in mind that all text is summarized by machine, we do not bear any responsibility, and you should always check original source before taking any actions