This late and delayed depolarization is oriented from endocard to epicard. The terminal vectors which causes the R are contrary to the initial vectors which produce the Q-wave. An intraventricular block appears as a temporal phenomenon with hyperkalaemia and hypothermia. As permanent phenomenon it is seen in diffuse damage of the myocard and a great decompensated heart. Back to Top 7.11 Aberrant conduction If a supraventricular impulse is abnormally conducted through the intraventricular conduction fibers, we speak of aberrant conduction.
Aberrant conduction is a temporal and frequency dependent phenomenon.
The QRS has the shape of a bundle branch block, often of a RBBB, or a fascicular block. It is also possible that the QRS is only slightly abnormal and slightly widened. This is caused by the different refractory periods of the different fibers. In normal circumstances the refractory period of the right bundle is slightly longer then of the left bundle. The Ashman phenomenon pleas for aberrant conduction.