Systems, devices, and methods for electroporation ablation therapy are disclosed, with a protection device for isolating electronic circuitry, devices, and/or other components from a set of electrodes during a cardiac ablation procedure. A system can include a first set of electrodes disposable near cardiac tissue of a heart and a second set of electrodes disposable in contact with patient anatomy. The system can further include a signal generator configured to generate a pulse waveform, where the signal generator coupled to the first set of electrodes and configured to repeatedly deliver the pulse waveform to the first set of electrodes. The system can further include a protection device configured to selectively couple and decouple an electronic device to the second set of electrodes.