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document
Lack of benefit of an active pectoral pulse generator on atrial defibrillation thresholds . INTRODUCTION Atrial defibrillation can be achieved with standard implantable cardioverter defibrillator leads , which has led to the development of combined atrial and ventricular devices . For ventricular defibrillation , use of an active pectoral electrode ( active can ) in the shocking pathway markedly reduces defibrillation thresholds ( DFTs ) . However , the effect of an active pectoral can on atrial defibrillation is unknown . METHODS AND RESULTS This study was a prospective , randomized , paired comparison of two shock configurations on atrial DFTs in 33 patients . The lead system evaluated was a dual-coil transvenous defibrillation lead with a left pectoral pulse generator emulator . Shocks were delivered either between the right ventricular coil and proximal atrial coil ( lead ) or between the right ventricular coil and an active can in common with the atrial coil ( active can ) . Delivered energy at DFT was 4.2 +/- 4.1 J in the lead configuration and 5.0 +/- 3.7 J in the active can configuration ( P = NS ) . Peak current was 32 % higher with an active can ( P < 0.01 ) , whereas shock impedance was 18 % lower ( P < 0.001 ) . Moreover , a low threshold ( < or = 3 J ) was observed in 61 % of subjects in the lead configuration but in only 36 % in the active can configuration ( P < 0.05 ) . There were no clinical predictors of the atrial DFT . CONCLUSION These results indicate that low atrial DFTs can be achieved using a transvenous ventricular defibrillation lead . Because no benefit was observed with the use of an active pectoral electrode for atrial defibrillation , programmable shock vectors may be useful for dual-chamber implantable cardioverter defibrillators .
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Intervention_Surgical
active pectoral pulse generator
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Intervention_Surgical
active pectoral electrode ( active can )
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Intervention_Physical
active pectoral can
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Intervention_Other
comparison of two shock configurations
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Intervention_Surgical
dual-coil transvenous defibrillation
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Intervention_Surgical
left pectoral pulse generator emulator
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Intervention_Surgical
active can
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Intervention_Other
active can
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Intervention_Surgical
active can
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Intervention_Surgical
active pectoral electrode
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Outcome_Physical
Delivered energy at DFT
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Outcome_Physical
Peak current
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Outcome_Physical
shock impedance
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Outcome_Physical
low threshold
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Outcome_Physical
no clinical predictors