on 7.12.08 with 0 comments

  • normally, conduction activates heart in sequence. the wave of depolarization is extinguished, requiring subsequent SA node discharge to depolarize the myocardium for the next beat

  • in reentry, a group of cells is not activated by SA node but is rather activated in a retrograde fashion, serving as a bridge to reactivate areas that have now recovered

  • three requirements for reentry—this is very important

    • 1 dispersion of repolarization: tissues repolarize again at varying rates

    • 2 unidirectional conduction block

    • 3 slow conduction: even without specialized conduction tissue, heart tissue normally transmits potentials so fast that reentry would not occur even if the other two criteria were present

Category: Cardiology Notes



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