title: Respiratory cycle-dependent atrial tachycardia: prevalence, electrocardiographic and electrophysiologic characteristics, and outcome after catheter ablation.
abstract: BACKGROUND
  Little is known about the tachyarrhythmias relating to respiration. Case reports presented patients with respiratory cycle-dependent atrial tachycardias (RCATs), which cyclically emerge after starting inspiration and cease during expiration.
  
  
  OBJECTIVE
  The aim of the present study was to elucidate the prevalence, characteristics, and long-term outcome after radiofrequency catheter ablation (RFCA) of RCATs.
  
  
  METHODS
  The electrocardiographic and electrophysiologic properties and results of RFCA were analyzed in 60 patients with a total of 71 focal atrial tachycardias (ATs).
  
  
  RESULTS
  Nine RCATs (13%) were observed in 7 patients (12%). RCATs were irregular, with a mean cycle length ranging from 220 to 650 ms, and developed incessantly accounting for 32% ± 14% of the 24-hour heartbeats. The P-wave morphology was positive or biphasic (positive to negative) in V1, and positive in I and II. The electroanatomical mapping demonstrated a centrifugal activation pattern, with the earliest site located at the antrum of the right superior pulmonary vein (RSPV), inside the RSPV, and inside the superior vena cava (SVC) in 4, 2, and 3 RCATs, respectively. Radiofrequency energy delivery at the earliest site or the electrical isolation of the RSPV and SVC suppressed all RCATs. During a follow-up of 25 ± 15 months, 1 RCAT recurred and was eliminated in a second procedure.
  
  
  CONCLUSIONS
  RCATs were observed in 13% of the focal ATs. As presumed from the P-wave morphologies, their foci converged around the RSPV or inside the SVC. RFCA was effective to eliminate RCATs.
authors.affiliation: Department of Cardiology, Nippon Medical School, Tokyo, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Meiso
authors.initials: M
authors.lastname: Hayashi
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Miyauchi
authors.forename: Hiroshige
authors.initials: H
authors.lastname: Murata
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Horie
authors.forename: Osamu
authors.initials: O
authors.lastname: Igawa
authors.forename: Takao
authors.initials: T
authors.lastname: Kato
authors.forename: Kyoichi
authors.initials: K
authors.lastname: Mizuno
mesh_terms: D000328:Adult; D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology; D017115:Catheter Ablation; D016009:Chi-Square Distribution; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011667:Pulmonary Veins / Q000503:physiopathology* / Q000601:surgery*; D012119:Respiration; D018709:Statistics, Nonparametric; D013612:Tachycardia, Ectopic Atrial / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome; D014683:Vena Cava, Superior / Q000503:physiopathology* / Q000601:surgery*