Rapid Pacing of Weak Stimuli in the Heart. Deborah Janks and Bradley J. Roth, Oakland University, Department of Physics, Rochester, MI 48309 With the development of pacemakers and defibrillators comes an important question: what are the underlying mechanisms responsible for the induction of reentry within the heart? At least two mechanisms are known to lead to an arrhythmia (or "reentry"): inhomogeneities occurring within the tissue as well as a difference in electrical conductivity parallel and perpendicular to the fibers surrounding an electrode. Each of these mechanisms were modeled with the objective being to determine the dominant mechanism responsible for reentry. Our results are compared to experimental studies leading to the conclusion that the different electrical conductivity parallel and perpendicular to the fibers leads to results that agree more closely to those observed experimentally.
