A system includes a pulse waveform generator and an ablation device coupled to the pulse waveform generator. The ablation device includes at least one electrode configured for ablation pulse delivery to tissue during use. The pulse waveform generator is configured to deliver voltage pulses to the ablation device in the form of a pulsed waveform. A first level of a hierarchy of the pulsed waveform includes a first set of pulses, each pulse having a pulse time duration, with a first time interval separating successive pulses. A second level of the hierarchy of the pulsed waveform includes a plurality of first sets of pulses as a second set of pulses, a second time interval separating successive first sets of pulses, the second time interval being at least three times the duration of the first time interval.
