title: Prevention of immediate reinitiation of atrial tachyarrhythmias by high-rate overdrive pacing: results from a prospective randomized trial.
abstract: BACKGROUND
  Immediate reinitiation of atrial tachyarrhythmia (IRAT) is an important cause of failure to maintain sinus rhythm. IRAT prevention by overdrive pacing has not been evaluated in a prospective randomized trial.
  
  
  RESULTS
  Patients with a DDDRP pacemaker offering temporary atrial overdrive pacing after AT termination (Post Mode Switching Overdrive Pacing [PMOP]) were enrolled into the prospective PIRAT (Prevention of IRAT) trial if paroxysmal AT episodes occurred after implantation. PMOP was randomly activated (120 beats/min for 2 min) or inactive. After 3 months, device memory was interrogated, symptoms and quality of life assessed, and patients crossed over to the alternative treatment arm for another 3 months. Primary study endpoint was the number of AT episodes; secondary endpoints were the cumulative time in AT (AT burden), percentage of AT episodes with IRAT, symptoms, and quality of life with PMOP active versus inactive. In 37 patients (21 men; 69 +/- 9 years), there was no difference in the median number of AT episodes (0.37 vs 0.34 per day), AT burden (both 1%), percentage of episodes with IRAT (30%vs 28%), symptoms, and quality of life during PMOP off versus on. With PMOP active, 29% of 439 ATs restarted during and 18% before PMOP intervention. The PMOP-induced rate increase appeared to be associated with IRAT in 9% of AT episodes.
  
  
  CONCLUSIONS
  Automatic overdrive pacing after AT termination did not prevent IRAT, mainly due to insufficient overdrive suppression even at 120 beats/min and the delay between AT termination and PMOP intervention.
authors.affiliation: Department of Medicine, Division of Cardiology, J.W. Goethe-University Hospital, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
authors.forename: Carsten W
authors.initials: CW
authors.lastname: Israel
authors.forename: Gerian
authors.initials: G
authors.lastname: Grönefeld
authors.forename: Joachim R
authors.initials: JR
authors.lastname: Ehrlich
authors.forename: Yi-Gang
authors.initials: YG
authors.lastname: Li
authors.forename: Stefan H
authors.initials: SH
authors.lastname: Hohnloser
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D018592:Cross-Over Studies; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006325:Heart Atria; D006801:Humans; D008297:Male; D008875:Middle Aged; D055502:Secondary Prevention; D013610:Tachycardia / Q000175:diagnosis / Q000517:prevention & control*; D017211:Treatment Failure