Abstract: A capacitor-discharge implantable cardioverter defibrillator (ICD) has a relatively smaller displacement volume of less than about 90 cc. The smaller volume of the ICD is achieved by selecting and arranging the internal components of the ICD to deliver a maximum defibrillation countershock optimized in terms of a minimum physiologically effective current (I.sub.pe), rather than a minimum defibrillation threshold energy (DFT). As a result of the optimization in terms of a minimum effective current I.sub.pe, there is a significant decrease in the maximum electrical charge energy (E.sub.c) that must be stored by the capacitor of the ICD to less than about 30 Joules, even though a higher safety margin is provided for by the device. Due to this decrease in the maximum E.sub.
June 21, 1994
Date of Patent:
April 11, 1995
Mark W. Kroll, Theodore P. Adams, Kenneth M. Anderson, Charles U. Smith