Abstract: The present invention provides a system and method for delivering a defibrillation waveform which is a fractal or multifractal pulse sequence. In one embodiment of the invention, a plurality of monophasic rectangular or truncated exponential pulses are delivered with fractal timing. Each subsequent pulse in the sequence has a lower voltage than the preceding pulse and the pulses have equal duration. This fractal pulse sequence is generated in response to a sensed arrhythmia and it is delivered using conventional leads to a patient's heart. A predetermined fractal pulse sequence is stored in programmable memory and may be modified by a patient's physician.