A method of testing a therapeutic pulse generator circuit is disclosed. The method includes charging the pulse generator circuit to a first charge voltage, with the pulse generator circuit, delivering a first voltage pulse to a load through an electrode, and determining an impedance of the load with the first voltage pulse. The method also includes comparing the impedance with an expected impedance, as a result of the comparison, determining to deliver a second voltage pulse to the load based, and delivering the second voltage pulse to the load, where at least one of the first and second voltage pulses is therapeutic to the load.