Because the normal ventricular conduction system (His-Purkinje ... The strip below shows a junctional rhythm with retrograde P waves seen just before the QRS complex. The second rhythm strip ...

The direction of conduction to the atria in a junctional ... is present which would widen the QRS complex. In case #7 a retrograde P wave can be identified just before the QRS complex with a ...

So, early V during anterograde conduction identifies V insertion; early A during retrograde conduction identifies atrial insertion. The use of "earliest activation" to identify an insertion site ...

Concealed retrograde conduction into the AV node by ventricular pacing may slow AV conduction and avoid undue increase in ventricular rates. Another algorithm, available in Medtronic, Guidant ...