title: Low-energy transvenous cardioversion of atrial fibrillation using a single atrial lead system.
abstract: BACKGROUND
  Clinical studies have shown that electrical conversion of atrial fibrillation (AF) is feasible with transvenous catheter electrodes at low energies. We developed a single atrial lead system that allows atrial pacing, sensing, and defibrillation to improve and facilitate this new therapeutic option.
  
  
  RESULTS
  The lead consists of a tripolar sensing, pacing, and defibrillation system. Two defibrillation coil electrodes are positioned on a stylet-guided lead. A ring electrode located between the two coils serves as the cathode for atrial sensing and pacing. We used this lead to cardiovert patients with acute or chronic AF. The distal coil was positioned in the coronary sinus, and the proximal coil and the ring electrode in the right atrium. R wave synchronized biphasic shocks were delivered between the two coils. Atrial signal detection and pacing were performed using the proximal coil and the ring electrode. Eight patients with acute AF (38 +/- 9 min) and eight patients with chronic AF (6.6 +/- 5 months) were included. The fluoroscopy time for lead placement was 3.5 +/- 4.3 minutes. The atrial defibrillation threshold was 2.0 +/- 1.4 J for patients with acute AF and 9.2 +/- 5.9 J for patients with chronic AF (P < 0.01). The signal amplitude detected was 1.7 +/- 1.1 mV during AF and 4.0 +/- 2.9 mV after restoration of sinus rhythm (P < 0.001). Atrial pacing was feasible at a threshold of 4.4 +/- 3.3 V (0.5-msec pulse width).
  
  
  CONCLUSIONS
  Atrial signal detection, atrial pacing, and low-energy atrial defibrillation using this single atrial lead system is feasible in various clinical settings. This system might lead to a simpler, less invasive approach for internal atrial cardioversion.
authors.affiliation: Medizinische Universitätsklinik, Innere Medizin III, Homburg/Saar, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Heisel
authors.forename: J
authors.initials: J
authors.lastname: Jung
authors.forename: J
authors.initials: J
authors.lastname: Neuzner
authors.forename: U
authors.initials: U
authors.lastname: Michel
authors.forename: H
authors.initials: H
authors.lastname: Pitschner
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000628:therapy*; D002908:Chronic Disease; D017147:Defibrillators, Implantable / Q000009:adverse effects; D004554:Electric Countershock / Q000009:adverse effects / Q000295:instrumentation*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged