Does reducing capacitance have potential for further miniaturisation of implantable defibrillators?
Journal Article (Journal Article)
ObjectiveTo determine whether considerably smaller capacitors could replace 125 microF capacitors as the standard for use in implantable defibrillators.
MethodsMeasured energy, impedance, voltage, and current delivered were compared at defibrillation threshold in 10 mongrel dogs for defibrillation using 75 microF and 125 microF capacitors alternated randomly. Defibrillation was attempted with biphasic shocks of comparable tilt between an endocardial lead in the right ventricular apex and a "dummy" active can of an experimental implantable device placed in the subpectoral position.
ResultsA reduction of capacitor size of 40% was associated with an increase in voltage of 21% and in current of 22%. With a 65% tilt, no significant differences were found between the two capacitances with respect to the impedance or energy required for defibrillation.
ConclusionsMultiple advances in electrode material, electrode configuration, shock morphology, and shock polarity have reduced defibrillation energy requirements. Smaller capacitors could be used in implantable cardioverter/defibrillators without a major decrease in effectiveness.
- Alt, E; Evans, F; Wolf, PD; Pasquantonio, J; Stotts, L; Heinz, S; Schömig, A
- March 1997
Volume / Issue
- 77 / 3
Start / End Page
- 234 - 237
Pubmed Central ID
Electronic International Standard Serial Number (EISSN)
International Standard Serial Number (ISSN)
Digital Object Identifier (DOI)