4,200
edits
Intraventricular Conduction: Difference between revisions
Jump to navigation
Jump to search
m
→Mechanisms of aberrant conduction
m (→LBBB vs RBBB) |
|||
| Line 84: | Line 84: | ||
===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== | ||