title: Clinical and electrophysiological characteristics of patients having atrial flutter with 1:1 atrioventricular conduction.
abstract: OBJECTIVE
  The purpose of this retrospective study was to assess characteristics of patients who had suffered atrial flutter (AFL) with 1:1 atrioventricular (AV) conduction (1:1 AFL).
  
  
  RESULTS
  Subjects were 8 patients (61 +/- 14 years) with documented 1:1 AFL, and 101 AFL patients without a history of 1:1 AFL (control patients). 1:1 AFL occurred during physical activity with a ventricular rate of 218 +/- 18 bpm. Antiarrhythmic agents were administered to all eight 1:1 AFL patients, whereas AV nodal conduction-suppressing agents were administered to four. The maximum ventricular rate at which 1:1 AV conduction occurred was significantly lower than when spontaneous 1:1 AFL occurred (164 vs. 218 bpm, P < 0.05). The 1:1 AFL patients had a significantly longer AFL cycle length (CL) (292 vs. 258 ms, P < 0.05) and more rapid AV nodal conduction time (maximum 1:1 AV conduction: 375 vs. 464 ms, P < 0.05) than did control. Arrhythmia had occurred in patients with an AFL CL > or = 250 ms and a CL of maximum 1:1 AV conduction < or = 400 ms.
  
  
  CONCLUSIONS
  Clinicians should be aware of the potential for 1:1 AV conduction in AFL patients, especially in those with remarkable prolongation of the CL in addition to enhanced AV conduction.
authors.affiliation: Department of Cardiovascular Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. mihoko_kawabata.cvm@tmd.ac.jp
authors.forename: Mihoko
authors.initials: M
authors.lastname: Kawabata
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hirao
authors.forename: Kouji
authors.initials: K
authors.lastname: Higuchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sasaki
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Furukawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Okada
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hachiya
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Isobe
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000638:Amiodarone / Q000009:adverse effects / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects / Q000627:therapeutic use; D001282:Atrial Flutter / Q000209:etiology / Q000503:physiopathology* / Q000628:therapy; D016022:Case-Control Studies; D017115:Catheter Ablation; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005424:Flecainide / Q000009:adverse effects / Q000627:therapeutic use; D006325:Heart Atria / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D007093:Imidazoles / Q000009:adverse effects / Q000627:therapeutic use; D008012:Lidocaine / Q000009:adverse effects / Q000031:analogs & derivatives / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D000889:Anti-Arrhythmia Agents; D007093:Imidazoles; D008012:Lidocaine; C042288:pilsicainide; D005424:Flecainide; D000638:Amiodarone; C032151:cifenline