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Intraventricular Conduction: Difference between revisions
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===Phase 4 Aberration=== | ===Phase 4 Aberration=== | ||
Phase 4 aberration only occurs after prolonged pause. During such a pause (e.g. in second degree AV block) the fibers of the Purkinje system can 'hyper'-depolarize spontaneously. As their membrane potential becomes more and more negative the conduction velocity reduces and they can even block altogether. This also requires an upwards shift of the threshold membrane potential and a change in membrane responsiveness, so it is rarely seen in normal hearts. | Phase 4 aberration only occurs after prolonged pause. During such a pause (e.g. in second degree AV block) the fibers of the Purkinje system can 'hyper'-depolarize spontaneously. As their membrane potential becomes more and more negative the conduction velocity reduces and they can even block altogether. This also requires an upwards shift of the threshold membrane potential and a change in membrane responsiveness, so it is rarely seen in normal hearts. | ||
==References== | ==References== | ||