Prevention of sustained ventricular tachyarrhythmias in patients with implantable cardioverter-defibrillators-the PREVENT study.
BACKGROUND
In patients with implantable cardioverter-defibrillators (ICDs), 25 to 45% of tachyarrhythmia episodes were initiated by short-long-short RR intervals.


METHODS
The prospective multi-center PREVENT study randomized patients implanted with ICDs capable of atrioventricular pacing, in order to compare-using a cross-over design with two 3-month treatment periods-the benefits of 'rate smoothing' (RS) as a 'pause-prevention algorithm' for the prevention of ventricular tachyarrhythmias.


RESULTS
Follow-up included 219 patients with implanted ICDs, of whom 153 were eligible for analysis as per protocol. Fifty-seven of these patients (38%) had documented episodes of ventricular tachyarrhythmias during the six months follow-up. The total number of sustained ventricular tachyarrhythmia episodes was reduced from 358 with RS Off to 145 with RS On. RS was effective in reducing the number of short-long-short induced sustained ventricular episodes from 100 with RS Off to 40 with RS On. The Wilcoxon-Mann-Whitney point estimator equals 0.66 with a 95% confidence interval from 0.51 to 0.82 (relevant superiority; corresponding p = 0.039). There were no proarrhythmic effects due to rate smoothing within the scope of this study.


CONCLUSIONS
'Rate smoothing' significantly reduced sustained ventricular tachyarrhythmias in ICD patients. There is a relevant superiority of the treatment during the early six months of follow-up.
Wietholt
Dietmar
D
Department of Internal Medicine/Cardiology, Emergency Hospital Berlin, Germany. dietmar.wietholt@ukb.de
Kuehlkamp
Volker
V
Meisel
Ekkhard
E
Hoffmann
Ellen
E
Stellbrink
Christoph
C
Neuzner
Joerg
J
Seidl
Karl
K
Szigat
Peter
P
Potratz
Juergen
J
D000368:Aged; D000465:Algorithms; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D018592:Cross-Over Studies; D017147:Defibrillators, Implantable; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017180:Tachycardia, Ventricular / Q000517:prevention & control*