title: Dexmedetomidine Depresses Sinoatrial and Atrioventricular Nodal Function Without Any Change in Atrial Fibrillation Inducibility.
abstract: It has been reported that dexmedetomidine (dex) has an impact on the cardiac conduction system and even has potential antiarrhythmic actions. We examined the influence of dex on the cardiac electrophysiological properties and atrial fibrillation (AF) inducibility. Adult paroxysmal AF patients were randomly assigned to receive (N = 107) or not receive (N = 108) dex during cardiac electrophysiological studies. The corrected sinus node recovery time (558 ± 331 vs. 459 ± 260 milliseconds; P = 0.02), Wenckebach cycle length (P < 0.001), atrioventricular nodal effective refractory period (317 ± 76 vs. 252 ± 54 milliseconds; P < 0.001), and atrio-His interval (P < 0.001) were longer in patients with dex than in those without. We tested the induction of repetitive atrial firing (RFA) defined as the occurrence of ≥2 successive atrial activities induced by single premature atrial stimuli to determine the AF inducibility. RFA was seen with a similar proportion (41.1% vs. 44.4%), yet it was evoked at a longer stimulus coupling interval in the dex patients, which was potentially attributed to the longer atrial effective refractory period (237 ± 36 vs. 213 ± 27 milliseconds; P < 0.001) and more prolonged atrial conduction delay seen in the dex group. In conclusion, dex may depress the sinus and atrioventricular nodal function, however, it may not reduce the AF inducibility.
authors.affiliation: Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Sairaku
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Nakano
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Suenari
authors.forename: Takehito
authors.initials: T
authors.lastname: Tokuyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawazoe
authors.forename: Hiroya
authors.initials: H
authors.lastname: Matsumura
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Tomomori
authors.forename: Michitaka
authors.initials: M
authors.lastname: Amioka
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Kihara
mesh_terms: D058647:Adrenergic alpha-2 Receptor Agonists / Q000009:adverse effects / Q000494:pharmacology*; D000368:Aged; D001281:Atrial Fibrillation / Q000139:chemically induced / Q000503:physiopathology*; D016275:Atrial Function / Q000187:drug effects* / Q000502:physiology; D020927:Dexmedetomidine / Q000009:adverse effects / Q000494:pharmacology*; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006329:Heart Conduction System / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012849:Sinoatrial Node / Q000187:drug effects* / Q000502:physiology
chemical_list: D058647:Adrenergic alpha-2 Receptor Agonists; D020927:Dexmedetomidine