Demand failures occurring during permanent pacing in patients with serious heart disease.
Demand failures during permanent cardiac Spacing were studied in four patients with coronary heart disease and cardiomyopathies, by means of in vivo and in vitro analyses of the pacemaker system. A common feature of the electrogram analyses (except during a second replacement in one patient), was ex...
| Publicado en: | Pacing & Clinical Electrophysiology Vol. 3; no. 1; pp. 44 - 56 |
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| Autor principal: | |
| Formato: | case study Journal Article |
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Wiley-Blackwell
Jan1980
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=106086043&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 106086043 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 01478389 4F8 jtl: Pacing & Clinical Electrophysiology issn: 01478389 maglogo: Y pubinfo: dt: Jan1980 vid: 3 iid: 1 pid: 480 pub: Wiley-Blackwell place: Malden, Massachusetts artinfo: ui: 106086043 2009410105 10.1111/j.1540-8159.1980.tb04302.x NLM6160493 106086043 ppf: 44 ppct: 12 formats: fmt: @attributes: type: P tig: atl: Demand failures occurring during permanent pacing in patients with serious heart disease. aug: au: Ohm O sug: subj: Coronary Disease Physiopathology Myocardial Diseases Physiopathology Pacemaker, Artificial Adult Aged Death, Sudden Etiology Electrodes, Implanted Electrophysiology Female Male Middle Age Adult: 19-44 years Aged: 65+ years Middle Aged: 45-64 years Female Male ab: Demand failures during permanent cardiac Spacing were studied in four patients with coronary heart disease and cardiomyopathies, by means of in vivo and in vitro analyses of the pacemaker system. A common feature of the electrogram analyses (except during a second replacement in one patient), was extremely low values of amplitudes (0.77-4.36 mV) and maximum derivatives (0.16-1.06 V/sec). In spite of low electrogram amplitudes, the myocardial threshold values were low in all patients. An attempt in one patient at unipolarizing a bipolar system made the adaptation between electrogram and pulse generator more difficult. Autopsy showed that the lip of the bipolar electrode was positioned in a fibrotic area of the myocardium. The signal available for the sensing circuit will also be reduced because of voltage division between the electrode/tissue interface impedance and the input impedance of the pulse generator. Although the pulse generators used had a high input impedance (10-50 K), the tissue interface impedance may have caused a further reduction in the electrogram amplitude of 10-30%. This may have contributed to demand failure. In vitro studies confirmed that test pulses with characteristics similar to those of the electrograrns found in this investigation, were inadequate for pacemaker inhibition. Special care should be taken during electrogram recordings in patients with severe myocardial disease. One should consider the implantation of a high sensitivity pulse generator or the recently introduced sensitivity programmable pulse generators as first choice for this group of patients. pubtype: Academic Journal doctype: case study Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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