A method of delivering pulsed electrical energy to a target tissue region includes delivering a first therapeutic pulse, the delivering of the first therapeutic pulse includes delivering a first pulse for a first time period, the first pulse having a first voltage amplitude. A second pulse is delivered immediately after the first pulse for a second time period, the second pulse having a second voltage amplitude configured to electroporate the target tissue region, the second time period being less than the first time period. A third pulse is delivered without delay after the second pulse for a third time period, the third pulse having a third voltage amplitude being at least one from the group consisting of substantially the same as the first amplitude, larger than the first amplitude, and less than the first amplitude.