Plateau waveform shape allows a much higher patient shock energy tolerance in AF patients.

Objectives: To evaluate the possible pain reduction of the plateau waveform in atrial fibrillation (AF) patients.

Background: Previous studies have indicated that reduced amplitude waveforms would be less painful than a conventional (65/65% tilt) biphasic waveform. Computer modeling suggested that a moderately long (10-12 msec) plateau (flat topped) shock waveform would deliver equivalent effectiveness with the lowest possible peak amplitude.

Stepped defibrillation waveform is substantially more efficient than the 50/50% tilt biphasic.

Background: Even with biphasic waveforms, patients with high defibrillation thresholds (DFTs) still are seen; thus, improved defibrillation waveforms may be of clinical utility. The stepped waveform has three parts: the first portion is positive with two capacitors in parallel, the second is positive with the capacitors in series, and the last portion is negative, also with the capacitors in series.

Objectives: The purpose of this study was to assess the clinical utility of improved defibrillation waveforms.

Mechanisms of pain associated with internal defibrillation shocks: results of a randomized study of shock waveform.

Background: Shock pain has limited the acceptance of the implantable atrial cardioverter and is a complication of ventricular implantable cardioverter-defibrillator therapy. Rounding off of the peak of a shock waveform reduces pain. Whether the pain reduction results from reduction in the peak voltage or from the rounding has not been established.