Europace Advance Access originally published online on May 16, 2007
Europace 2007 9(7):506-513; doi:10.1093/europace/eum088
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PACING
Ventricular rate smoothing for atrial fibrillation: a quantitative comparison study
Applied Clinical Research Department, Micro Systems Engineering, Inc., 6024 SW Jean Road, Lake Oswego, OR 97035, USA
Aims To quantitatively compare the ventricular rate-smoothing (VRS) effects of different ventricular pacing (VP) protocols for atrial fibrillation (AF).
Methods and results Using a recently developed open-source model that can simulate the ventricular response in AF and VP, the performance of fixed-rate pacing and four previously published VRS algorithms were assessed by the mean RR (mRR), the root mean square of successive RR differences (RMSSD), the percentage of ventricular senses (VS%), and the percentage of short RR intervals (sRR%). All pacing protocols cause rate-dependent reduction of RMSSD, VS%, and sRR% with or without shortening of mRR compared to spontaneous AF. Fixed-rate pacing was more sensitive to the intrinsic rate than the VRS algorithms. The performance was generally comparable between different VRS algorithms, although higher mRR and VS% can be achieved at the expense of larger RMSSD and sRR%.
Conclusion The effect of VP on ventricular rhythm in AF depends on both intrinsic rate and the aggressiveness of the pacing protocol. Adequate rate control is necessary for effective operation of the VRS algorithm. Choosing VRS algorithm should balance between the beneficial effects of rate regularization and the negative effects of increasing heart rate and percentage of VP.
Key Words: Ventricular rate smoothing, Ventricular pacing, Atrial fibrillation, RR interval
* Corresponding author. Tel: +1 503 635 4016 ext 1401; fax: +1 503 635 9610. E-mail address: jie.lian{at}biotronik.com
Manuscript submitted 24 October 2006. Accepted after revision 7 April 2007.