Module 1
Topic 6
Lesson 19
No VA conduction and how to be sure
Acknowledgement
Serge Boveda
Head of Arrhythmia Unit
What will you learn?
- what VA block means for the potential diagnosis
- how to be sure the block is permanent
- what can influence VA conduction and block
About this scenario
- Retrograde (or V-A) conduction assessment during all EP studies is essential.
- Absence of retrograde conduction allows to rule out the presence of a retrograde accessory pathway.
- Retrograde conduction must be assessed, first in basal state, then after isoproterenol injection.
- Permanent capture of the ventricle (V) is mandatory in order to assess retrograde conduction.
- Pacing the ventricle at low rates (cycle length at 800-700 ms) is mandatory to correctly assess the retrograde conduction, in order to avoid being below the retrograde refractory period of the AV node.
- Assessing the regularity of Atrio-Atrial (A-A) intervals in sinus rhythm, and after V pacing, allows to confirm the absence of retrograde (V-A) conduction.
- Assessing the absence of modification of the atrial activation pattern inside the coronary sinus, first in sinus rhythm, and after V pacing, allows to confirm the absence of retrograde (V-A) conduction.
