A defibrillator produces a biphasic defibrillation pulse waveform with adjustable tilt for the second phase. The tilt of the second phase of the biphasic waveform can be controllably adjusted by selectively switching a current path which bypasses the patient during delivery of the second phase of the pulse. The inventive biphasic waveform can be delivered by a defibrillator with a single capacitance.
