July 1, 1998Journal of Cardiovascular Electrophysiology
Postshock Potential Gradients and Dispersion of Repolarization in Cells Stimulated with Monophasic and Biphasic Waveforms
Key result
In computer models of reciprocally polarized cells, biphasic stimuli caused a smaller dispersion of repolarization (1611 msec2 vs 1835 msec2) compared to monophasic stimuli.
Why the study?
Does biphasic stimulation cause a more uniform response than monophasic stimulation in computer models of isolated ventricular cells?
Population
Two computer models of an isolated ventricular cell simulating rapid pacing and elevated [K]o
Comparison
5-msec/5-msec symmetric biphasic stimuli… vs 10-msec rectangular monophasic stimuli delivered…
Design
Preclinical
Authors
Discussion
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Member takes
Implication
Supports biphasic waveform modeling to reduce dispersion; leaves open clinical translation from computational data.
Structured PICO
Does biphasic stimulation cause a more uniform response than monophasic stimulation in computer models of isolated ventricular cells?
P
Population
Two computer models of an isolated ventricular cell (reciprocally polarized and uniformly polarized cells) simulating rapid pacing and elevated [K]o
I
Intervention
5-msec/5-msec symmetric biphasic stimuli delivered in the relative refractory period
C
Comparator
10-msec rectangular monophasic stimuli delivered in the relative refractory period
O
Outcome
Response duration and postshock transmembrane potential (Vm), including spatial gradients and dispersion of repolarizationsurrogate
Main Result
Absolute Event Rate: 1611% vs 1835%
Computer modeling suggests biphasic defibrillation waveforms cause a more uniform response in relatively refractory cardiac cells under reciprocal polarization, potentially explaining their greater efficacy in preventing refibrillation.
Cite This Study
Sobie et al. (1998) studied Ventricular fibrillation. Biphasic stimuli vs. Monophasic stimuli was evaluated on Dispersion of repolarization (with reciprocal polarization). In computer models of reciprocally polarized cells, biphasic stimuli caused a smaller dispersion of repolarization (1611 msec2 vs 1835 msec2) compared to monophasic stimuli.