This clip is really underrated! It is so clear to clarify the difference of the AVD and CHB. Thanks a lot!!! Hope you can make more informative videos~~~
QRS narrow because they are not originating from ventricles .Instead they are junctional escape rhythm not in synchrony with atrial p waves .junctional means nodal activity which are finally passing out through bubble branches to activate the ventricles thereby producing narrow QRS complexes