title: Detection of atrial fibrillation and flutter by a dual-chamber implantable cardioverter-defibrillator. For the Worldwide Jewel AF Investigators.
abstract: BACKGROUND
  To distinguish prolonged episodes of atrial fibrillation (AF) that require cardioversion from self-terminating episodes that do not, an atrial implantable cardioverter-defibrillator (ICD) must be able to detect AF continuously for extended periods. The ICD should discriminate between atrial tachycardia/flutter (AT), which may be terminated by antitachycardia pacing, and AF, which requires cardioversion.
  
  
  RESULTS
  We studied 80 patients with AT/AF and ventricular arrhythmias who were treated with a new atrial/dual-chamber ICD. During a follow-up period lasting 6+/-2 months, we validated spontaneous, device-defined AT/AF episodes by stored electrograms in all patients. In 58 patients, we performed 80 Holter recordings with telemetered atrial electrograms, both to validate the continuous detection of AT/AF and to determine the sensitivity of the detection of AT/AF. Detection was appropriate in 98% of 132 AF episodes and 88% of 190 AT episodes (98% of 128 AT episodes with an atrial cycle length <300 ms). Intermittent sensing of far-field R waves during sinus tachycardia caused 27 inappropriate AT/AF detections; these detections lasted 2.6+/-2.0 minutes. AT/AF was detected continuously in 27 of 28 patients who had spontaneous episodes of AT/AF (96%). The device memory recorded 90 appropriate AT/AF episodes lasting >1 hour, for a total of 2697 hours of continuous detection of AT/AF. During Holter monitoring, the sensitivity of the detection of AT/AF (116 hours) was 100%; the specificity of the detection of non-AT/AF rhythms (1290 hours) was 99.99%. Of 166 appropriate episodes detected as AT, 45% were terminated by antitachycardia pacing.
  
  
  CONCLUSIONS
  A new ICD detects AT/AF accurately and continuously. Therapy may be programmed for long-duration AT/AF, with a low risk of underdetection. Discrimination of AT from AF permits successful pacing therapy for a significant fraction of AT.
authors.affiliation: Cedars-Sinai Medical Center, Los Angeles, CA, USA. swerdlow@ucla.edu
authors.forename: C D
authors.initials: CD
authors.lastname: Swerdlow
authors.forename: W
authors.initials: W
authors.lastname: Schsls
authors.forename: B
authors.initials: B
authors.lastname: Dijkman
authors.forename: W
authors.initials: W
authors.lastname: Jung
authors.forename: N V
authors.initials: NV
authors.lastname: Sheth
authors.forename: W H
authors.initials: WH
authors.lastname: Olson
authors.forename: B D
authors.initials: BD
authors.lastname: Gunderson
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy; D001282:Atrial Flutter / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy; D009202:Cardiomyopathies / Q000150:complications; D017147:Defibrillators, Implantable; D003937:Diagnosis, Differential; D015716:Electrocardiography, Ambulatory; D005069:Evaluation Studies as Topic; D005189:False Positive Reactions; D005260:Female; D005500:Follow-Up Studies; D006331:Heart Diseases / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity