Giuseppe Boriani, Mauro Biffi, Luigi Padeletti*, Andrea Spampinato**, Gian Luca Botto***, Carlo Pignalberi****, Andrea Grammatico°, Micol Piana°, Sergio Cavaglia°, Francesco De Seta°, Angelo Branzi.
*Clinica Medica, University of Firenze, **Villa Tiberia, Roma, ***S. Anna Hospital, Como. ****Universita Campus Biomedico Roma, °Medtronic Italia, Italy
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In the last 10 years a series of retrospective studies1-6
showed that there was a higher risk of developing atrial fibrillation (AF) in patients with sick sinus
syndrome paced in the VVI mode than in those paced in AAI or DDD mode. Sgarbossa et al7 in a
retrospective study found that VVI pacing was associated to risk of developing chronic AF in
patients with preimplant AF but not in those without it. The prospective randomised study
reported by Andersen et al8, involving 225 patients, showed that more patients (23%)
randomised to VVI pacing developed AF over a 40-month period than patients randomised to AAI
pacing (14%). This difference, however, did not reach statistical significance.
In patients with sick sinus syndrome with an high risk of AF (brady-tachy syndrome), DDDR pacing
achieved a reduction of AF episodes both in comparison to baseline and to DDD pacing9.
The possible ways to positively influence the risk of atrial fibrillation (AF) involve pacing modality
(dual chamber or AAI vs VVI), pacing rate and extent of atrial overdrive, pacing site and, more
recently, use of dedicated pacing algorithms aimed to achieve a high percentage of atrial
stimulation. The electrophysiological background for using atrial pacing to prevent AF implies the
prevention of bradycardia-related AF episodes, the reduction of atrial premature complexes, the
prevention of short-long atrial cycles, the reduction in dispersion of conduction and refractoriness
and the reduction in stretch-induced atrial arrhythmias10,11.
Consistent Atrial Pacing (CAP) and Atrial Rate Stabilisation (ARS) are two new pacing algorithms for
preventing recurrent paroxysmal AF12.
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