Comparison of single-biphasic versus sequential-biphasic shocks on defibrillation threshold in pigs.
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 deliv...
| Published in: | Pacing & Clinical Electrophysiology Vol. 20; no. 6; pp. 1606 - 1613 |
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| Main Authors: | , , , |
| Format: | Journal Article |
| Published: |
Wiley-Blackwell
Jun1997
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| Online Access: | View this record in EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=106086309&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 106086309 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 01478389 4F8 jtl: Pacing & Clinical Electrophysiology issn: 01478389 maglogo: Y pubinfo: dt: Jun1997 vid: 20 iid: 6 pid: 480 pub: Wiley-Blackwell place: Malden, Massachusetts artinfo: ui: 106086309 2009411081 NLM9227756 106086309 ppf: 1606 ppct: 7 formats: fmt: @attributes: type: P tig: atl: Comparison of single-biphasic versus sequential-biphasic shocks on defibrillation threshold in pigs. aug: au: Csanadi Z Jones DL Kim Wood G Klein GJ sug: subj: Cardioversion Methods Defibrillators, Implantable Ventricular Fibrillation Therapy Animals Electrodes, Implanted Swine ab: 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-[mu]F 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. pubtype: Academic Journal doctype: Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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