Intraventricular Conduction: Difference between revisions

Intraventricular Conduction (view source)

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 :no or very few QRS widening;
 :Right ventricular [[hypertrophy]] and previous [[Ischemia#Lateral|lateral myocardial infarction]] have been excluded
+==Mechanisms of aberrant conduction==
+;Aberrant ventricular conduction is defined as
+:QRS widening due to delay or block in bundle branch or intramyocardial conduction<cite>wellens</cite>
+Aberrancy can result from:
+#A sudden fastening of the heart rate that the bundles cannot conduct (phase 3 aberration)
+#Retrograde concealed conduction
+#A slow heart rate (phase 4 aberration)
+Right bundle branch block is most common, because the right bundle has the longest refractory period. Left bundle branch block accounts for about 1/3rd of cases.
+===Phase 3 Aberration===
+Phase 3 aberration occurs when conduction fibers receive a new impulse, before they have fully repolarized. This can sometimes be observed at the start of paroxysmal supraventricular tachycardias or in a long-short sequence where the refractory periode of the long sequence is prolonged.
+===Retrograde Concealed Conduction===
+Phase 3 aberration is often the cause of the first wide QRS complex. However at a regular rate retrograde concealed conduction is often the sustaining mechanism. The sequence of QRS widening that is often observed is phase 3 aberration in the first premature beat. This can leave the left bundle (as an example) refractory for the next beat. This next beat is conducted by the right bundle and once it reaches the apex, it is conducted retrograde by the left bundle. through the by now Once this next beat has reached In retrograde concealed conduction the
+to be continued...
+===Phase 4 Aberration
 ==References==
 <biblio>
 #Garcia isbn=0763722464
+#wellens isbn=9781416002598
 </biblio>