Patent ID: 8886314

Claim:
A method for testing a defibrillation threshold of an implantable medical device, comprising: delivering a plurality of pacing pulses to a patient; monitoring a cardiac signal to derive a T-wave of the cardiac signal responsive to the delivered pacing pulses; identifying the ascending portion of the T-wave from the monitored cardiac signal; and configuring a therapy delivery circuit for delivery of therapy, wherein a plurality of capacitors of the therapy delivery circuit are dynamically stacked in: a parallel configuration for discharge of energy coincident with the ascending part of the T-wave to induce ventricular fibrillation, recharging the plurality of capacitors in the parallel configuration concurrently with the discharge of energy to induce ventricular fibrillation and prior to any reconfiguration of the dynamically stacked plurality of capacitors, and subsequently reconfiguring the stacking of the plurality of capacitors prior to delivering stimulation therapy in response to an onset of the induced ventricular fibrillation, wherein the reconfiguration comprises stacking the plurality of capacitors from the parallel configuration to a series configuration.