Clinical Electrophysiology -> SVT/AVNRT/WPW/AT: -> Epidemiology of Cardiac Arrhythmias/ Epidemiology D-PO04 - Poster Session IV (ID 15) Poster

D-PO04-233 - A Study On The Prevalence Of Upper Common Pathway In Atrio-ventricular Nodal Reentry Tachycardia Using Late Atrial Premature Depolarization (ID 1246)


Background: The presence of upper-common pathway (UCP) in atrio-ventricular nodal reentry tachycardia (AVNRT) is still controversial.
Objective: We assessed the prevalence of UCP by the response to late atrial premature depolarization (APD) during AVNRT.
Methods: Patients with sustained AVNRT during electrophysiology study were enrolled and underwent late APD maneuver. Initially, very late APD which is not able to reset the tachycardia was given at coronary sinus (CS) ostium during AVNRT, and then repeated APD was given incrementally by 5ms. When the APD first reset the tachycardia, we analyzed whether atrial electrogram at proximal his was reset. If a single UCP was present, APD will not be able to reset the tachycardia without resetting atrial electrogram at proximal his, which is the earliest atrial electrogram during AVNRT.
Results: Late APD maneuver was successfully performed in 23 patients. Among those, the APD from CS ostium reset tachycardia before resetting atrial electrogram at proximal his in 21 patients, which is diagnostic of the absence of a single UCP. Among two patients who showed the opposite response (reset of atrial electrogram at proximal his by the APD from CS ostium without altering tachycardia cycle), the final diagnosis was orthodromic nodo-ventricular reentry tachycardia in one patient. In 22 patients with confirmed AVNRT, the response to APD favored the presence of UCP in only one patient (1/22, 4.5%).
Conclusion: The rare existence of a single UCP in AVNRT was demonstrated by late APD from CS ostium in our study.