Journal of Arrhythmia (Dec 2023)

Landiolol, an intravenous β1‐selective blocker, is useful for dissociating a fusion of atrial activation via accessory pathway and atrioventricular node

  • Takahiko Kinjo,
  • Masaomi Kimura,
  • Noriyoshi Kaname,
  • Daisuke Horiuchi,
  • Taihei Itoh,
  • Yuji Ishida,
  • Kimitaka Nishizaki,
  • Yuichi Toyama,
  • Shingo Sasaki,
  • Hirofumi Tomita

DOI
https://doi.org/10.1002/joa3.12934
Journal volume & issue
Vol. 39, no. 6
pp. 937 – 946

Abstract

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Abstract Introduction During ventricular pacing, a fusion of atrial activation may occur owing to the simultaneous retrograde conduction of the atrioventricular (AV) node and accessory pathway (AP), potentially leading to an inaccurate mapping of the atrial AP insertion site. Objective We tested the hypothesis that landiolol, an ultra‐short‐acting intravenous β1‐blocker, could dissociate a fusion of atrial activation. Methods We conducted a prospective before‐and‐after study to investigate the effect of landiolol on retrograde conduction via the AV node and AP. We enrolled 21 consecutive patients with orthodromic AV reciprocating tachycardia who underwent electrophysiological studies at our hospital between January 1, 2018, and August 31, 2020. Results Six patients exhibited a fusion of atrial activation. After landiolol administration (10 μg/kg/min), the effective refractory period was unchanged in AP (280 [240–290] ms vs. 280 [245–295] ms, p = .91), whereas that of the AV node was prolonged (275 [215–380] ms vs. 332 [278–445] ms, p = .03). The Wenckebach pacing rate via retrograde AV node decreased after landiolol administration (180 [140–200] beats per minute [bpm] vs. 140 [120–180] bpm, p = .02). Thus, landiolol decreased the minimum ventricular pacing rate required to dissociate a fusion of atrial activation (180 [160–200] bpm vs. 140 [128–155] bpm, p = .007). Radiofrequency catheter ablation under landiolol administration successfully eliminated AP in all patients during ventricular pacing without complications or recurrence. Conclusion Landiolol inhibited the AV node without affecting the AP and helped dissociate a fusion of atrial activation at a lower ventricular pacing rate.

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