title: Correlation of spontaneous and induced premature atrial complexes initiating atrial fibrillation in humans: electrophysiologic parameters for guiding therapy.
abstract: BACKGROUND
  The low frequency of spontaneous premature atrial contractions (PACs) may be an impediment to mapping and ablation of atrial fibrillation (AF). It has been shown that PACs following external or internal cardioversion of AF can initiate AF. If this method could reproducibly induce PACs from the same location as spontaneous PACs, it would be clinically significant. High-resolution noncontact mapping can map a single beat, should help identify the sites of spontaneously occurring PACs and PACs induced following cardioversion of spontaneous or induced AF, and could help correlate the trigger sites for AF induction.
  
  
  RESULTS
  Twelve patients (8 men and 4 women; mean age 49+/-10 years) with spontaneous PACs were included in the study. In all patients, AF was induced and subsequently cardioverted to assess and map isolated PACs or PACs that induced AF. Using the EnSite 3000 noncontact mapping system, mapping was performed of spontaneously occurring isolated PACs and PACs that induced AF and PACs (both with and without AF) that occurred on at least two different occasions following cardioversion. The locations of the spontaneous and the induced PACs were similar; 97% of induced PACs came from the same locations as those of spontaneous PACs (P = 0.5). Radiofrequency lesions guided by this mapping technique were delivered at 14 pulmonary vein sites. Following a single ablation attempt during a mean follow-up of 19+/-4 weeks, 42% of the patients were in sinus rhythm and drug-free, whereas an additional 24% of patients could be maintained in sinus rhythm on drugs that had failed before.
  
  
  CONCLUSIONS
  There is a high degree of correlation between spontaneous and induced PACs as the trigger sites for AF initiation. Cardioversion of spontaneous or induced AF could be used as an electrophysiologic parameter for guiding therapy.
authors.affiliation: Electrophysiology Laboratories-Sinai Samaritan and St. Luke's Medical Centers, University of Wisconsin Medical School, Milwaukee, USA. bdanek@hrtcare.com
authors.forename: J
authors.initials: J
authors.lastname: Sra
authors.forename: S T
authors.initials: ST
authors.lastname: Zaidi
authors.forename: D
authors.initials: D
authors.lastname: Krum
authors.forename: N
authors.initials: N
authors.lastname: Georgakopoulos
authors.forename: A
authors.initials: A
authors.lastname: Ahmad
authors.forename: M
authors.initials: M
authors.lastname: Akhtar
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery; D018880:Atrial Premature Complexes / Q000150:complications / Q000503:physiopathology*; D018780:Body Surface Potential Mapping; D017115:Catheter Ablation / Q000379:methods; D002908:Chronic Disease; D004554:Electric Countershock / Q000379:methods; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome