The present disclosure provides systems and methods for cardiac stimulation. A cardiac stimulation device includes a plurality of electrodes, and a pulse circuit electrically coupled to the plurality of electrodes, the pulse circuit including a capacitor configured to charge to an initial charge level, deliver a test pulse having a first amplitude to the plurality of electrodes by only partially discharging, and subsequently deliver a backup pulse to the plurality of electrodes, the backup pulse having a second amplitude that is larger than the first amplitude.
