A patch in the pectoral position lowers defibrillation threshold.
Implantable pacemaker cardioverter defibrillators are now available with biphasic waveforms, which have been shown to markedly improve defibrillation thresholds (DFTs). However, in a number of patients the DFT remains high. Also, DFT may increase after implantation, especially if antiarrhythmic drugs are added. We report on the use of a subcutaneous patch in the pectoral position in 15 patients receiving a transvenous defibrillator as a method of easily reducing the DFT. A 660-mm2 patch electrode was placed beneath the generator in a pocket created on the pectoral fascia. The energy required for defibrillation was lowered by 56% on average, and the system impedance was lowered by a mean of 25%. This maneuver allowed all patients to undergo a successful implant with adequate safety margin.
Karasik
P
P
Department of Cardiology, VA Medical Center 20422, USA.
Solomon
A
A
Verdino
R
R
Moore
H
H
Rodak
D
D
Hannan
R
R
Fletcher
R
R
D017147:Defibrillators, Implantable; D017097:Electric Impedance; D004567:Electrodes, Implanted; D006801:Humans; D008297:Male; D008875:Middle Aged; D010369:Pectoralis Muscles