Upper common pathways analysis using late atrial premature depolarization in atrioventricular nodal reentry tachycardia

Introduction The presence of an upper common pathway (UCP) in atrioventricular nodal reentrant tachycardia (AVNRT) has been suggested. However, the precise anatomical description and the actual prevalence of UCP have not been well established. We aimed to assess the prevalence of UCP in AVNRT using a late atrial premature depolarization (LAPD) maneuver. Methods Patients who were diagnosed with typical AVNRT by electrophysiologic studies were enrolled. To evaluate the presence of UCP, a LAPD was given at the coronary sinus ostium (osCS) during AVNRT and then pacing was repeated incrementally every 10 ms. The result was interpreted as i) absence of UCP, a LAPD from osCS can reset the tachycardia without depolarizing the earliest retrograde atrial activation site (ERAS) near the proximal His; ii) presence of UCP, a LAPD from osCS can depolarize the ERAS without resetting the tachycardia; and iii) indeterminate, a LAPD from osCS either reset the ERAS and tachycardia simultaneously or does not reset both. Results The LAPD maneuver was performed in 126 patients with AVNRT and one patient with nodoventricular orthodromic reentrant tachycardia (NVORT). The maneuver result demonstrated an absence of UCP in 121 (96.0%) patients, a presence of UCP in 3 (2.4%) patients, and was indeterminate in 2 (1.6%) patients. In the patient with NVORT, the result was consistent with the presence of UCP. Conclusions The LAPD maneuver revealed that most AVNRTs did not exhibit a single UCP. The presence of UCP was suggested in 2.4% of AVNRT cases and one case of NVORT.