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Pacemakers for the treatment of bradyarrhythmias
Published in Ever D. Grech, Practical Interventional Cardiology, 2017
Device longevity is an important issue for implanters. Currently, batteries are lithium-based (lithium-iodine over the last few decades, but recently, lithium carbon monofluoride/silver vanadium oxide hybrid batteries are being used). Most dual chamber systems will endure usually 8–10 years. Battery depletion is gradual and current devices can estimate longevity (often a warning of battery depletion of at least 1 year is given). Battery replacement involves day-case surgery.
Procedures for Writing Formulas and Naming Compounds
Published in Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk, Survival Guide to General Chemistry, 2019
Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk
Write formulas for the following compounds based on the name given. Platinum (II) nitrate = Pt(NO3)2Aluminum hydroxide = Al(OH)3Potassium phosphate = K3PO4Manganese (II) hydrogen carbonate = Mn(HCO3)2Calcium permanganate = Ca(MnO4)2Ammonium chromate = (NH4)2CrO4Copper (I) nitrate = CuNO3Titanium (IV) perchlorate = Ti(ClO4)4Chlorine monofluoride = ClFSilicon tetrachloride = SiCl4Sulfur trioxide = SO3Iodine pentabromide = IBr5
Histopathologic Findings of Button Battery-Related Changes in a Perforated Meckel’s Diverticulum: Report of Three Cases
Published in Fetal and Pediatric Pathology, 2023
Tasnim Keloth, Badr AbdullGaffar, Munir Ahmad
The mechanisms by which button batteries cause tissue damage are mainly chemical [3–5,7–11]. They involve sequential multifactorial processes (Fig. 3). The heavy metal contents of the batteries are miscellaneous and might include zinc, silver, iron, mercury, lithium, copper, monofluoride and manganese. Leaching of corrosive metals may have secondary continuous tissue injury effects after disintegration of the battery. Studies on animal tissues have demonstrated that the above chemical events may occur rapidly in hours to few days with brown pigment deposition in injured tissues [12,13]. This explains the observed histopathologic findings in our series. There are also some concerns regarding heavy metal toxicity and blood poisoning due to leakage of corroded batteries [2,4,8,11]. Our cases demonstrated metallic element remnants very close to the submucosal congested blood vessels and in the inflamed serosa and omentum.
Leadless cardiac pacing systems: current status and future prospects
Published in Expert Review of Medical Devices, 2019
Niek E. G. Beurskens, Karel T. N. Breeman, Kosse J. Dasselaar, A. Chris Meijer, Anne-Floor B. E. Quast, Fleur V. Y. Tjong, Reinoud E. Knops
To date, two leadless pacemaker variants have been developed for patients with a single-chamber (VVI) pacemaker implantation: the Nanostim Leadless Cardiac Pacemaker (LCP; Abbott) and the Micra Transcatheter Pacing System (TPS; Medtronic). The Nanostim LCP has been CE approved in 2013 and awaits Food and Drug Administration (FDA) approval after major callbacks due to early battery depletion and docking button detaching. The Micra TPS was CE approved in 2015 and subsequently, FDA approved in 2016. [Figure 1] Both leadless pacemakers are fixated and fully contained in the right ventricle and provide similar functionality: right ventricular sensing/pacing and rate responsiveness. The systems differ in size (LCP 42 mm; TPS 25.9 mm), although having a comparable volume and weight (LCP 1.0 cc, 2 g; TPS 0.8 cc; 2 g). There are some differences between the Nanostim LCP and Micra TPS that should be emphasized. 1) The Nanostim LCP uses a thermal sensor and the Micra TPS a three-axis accelerometer as method of rate responsiveness. 2) For interrogation technology, Nanostim LCP uses ECG electrodes for limiting battery drainage, whereas the Micra TPS uses conventional radiofrequency currents. 3) The Nanostim LCP has a lithium carbon-monofluoride battery and the Micra TPS uses a silver vanadium lithium carbon-monofluoride battery. 4) The devices are anchored into the right ventricular myocardium in a different fashion: the Nanostim uses a screw-in-helix, whereas the Micra has 4 nitinol tines.