title: Impact of low-dose dipyridamole injection on adenosine test after pulmonary vein isolation.
abstract: BACKGROUND
  Dipyridamole increases the levels of extracellular adenosine. The study investigates the impact of low-dose intravenous dipyridamole on adenosine test after pulmonary vein (PV) isolation (PVI).
  
  
  RESULTS
  This prospective study included 12 paroxysmal atrial fibrillation (AF) patients (61 ± 12 years; nine men) who underwent PVI at the first procedure. Transient PV reconnection was provoked by adenosine test in 4/48 PVs. In 44 PVs without reconnection, intravenous infusion of low-dose (10 mg) dipyridamole preceded the adenosine test. Additional six patients (PVs) with transient dormant conduction were included. Among the total 10 PVs with transient reconnection, it was eliminated by radiofrequency (RF) application(s) until no dormant conduction was exposed by adenosine test(s) in five PVs. Then, dipyridamole potentiated adenosine test was undertaken to provoke dormant conduction (group 1). In the remaining five PVs, dipyridamole potentiated adenosine test was followed by RF elimination of conduction gap and repeat adenosine test to confirm complete elimination (group 2). Low-dose dipyridamole prolonged the duration of adenosine-induced atrioventricular block without vasodilatatory hypotension. There was no evidence of reconnection in 44 PVs without dormant conduction and in group 1 wherein transient reconnection was eliminated by 4.8 ± 3.2 RF applications in 8.8 ± 3.0 minutes and adenosine injected 3.1 ± 1.8 times. In group 2, dipyridamole plus adenosine test revealed the same dormant conduction that persisted longer than during adenosine alone. It was eliminated by single RF application in 3.4 ± 0.9 minutes, and adenosine was injected once.
  
  
  CONCLUSIONS
  Low-dose dipyridamole safely prolongs the electrophysiological effects of adenosine test without provoking additional PV reconnection. This allows sustained visualization and facilitates complete RF elimination of the electrical conduction gap.
authors.affiliation: Cardiology Division, Cardiovascular Center, Tsuchiura Kyodo Hospital, Ibaraki, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Miyazaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Taniguchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Uchiyama
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kusa
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hachiya
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hirao
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Iesaka
mesh_terms: D000241:Adenosine / Q000008:administration & dosage; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000601:surgery*; D004176:Dipyridamole / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D011667:Pulmonary Veins / Q000187:drug effects* / Q000601:surgery*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D014665:Vasodilator Agents; D004176:Dipyridamole; D000241:Adenosine
keywords: adenosine; catheter ablation; dipyridamole; dormant conduction; pulmonary vein isolation