14th International Congress
THE "NEW FRONTIERS"
OF ARRHYTHMIAS 2000

Jan. 29 - Feb. 5, 2000
Marilleva, Trento, Italy

RT-42

Atrial pacing reduces mode switching episodes in patients with paroxysmal atrial fibrillation

Giuseppe Stabile, Antonio De Simone, Dino Franco Vitale*, Pietro Turco, Vincenzo La Rocca, Gaetano Senatore**, Carmine De Matteis***, Raffaele Rotunno****, Tommaso Di Napoli****, Costantino Astarita°, Saverio Maresca°.
Laboratorio di Elettrofisiologia, Casa di Cura “San Michele” Maddaloni, *Dipartimento di Geriatria, Universita degli Studi di Napoli “Federico II”, Napoli, **Cardiologia, Ospedale Civile di Cirie, ***Servizio di Riabilitazione, Ospedale Civile di Arienzo, ****Unita Coronarica, Ospedale Civile di Polla, °Unita Operativa di Cardiologia, Ospedale Civile di Sorrento, Italy

Abstract

BACKGROUND. Pace-makers’ (PM) mode-switching (MS) algorithms are reliable in detecting paroxysmal episodes of atrial tachy- arrhythmias. So, in patients with paroxysmal atrial fibrillation (AF), their number may be correlated to AF episodes number. We prospectively analyze the effect of atrial pacing (AP) on MS episodes in patients with paroxysmal AF.

METHODS. Twenty-seven patients with paroxysmal AF, requiring dual chamber pace-maker (PM) implant, were enrolled. The PMs were programmed in DDD mode with the lower atrial rate at 50 beats/min. The atrial MS detection rate was programmed at 175 beats/min. At a follow-up of 4 months (follow-up period I), PM were reprogrammed in DDDR mode, with a lower rate of 75 beats/min, and followed-up for the next 4 months (follow-up period II).

RESULTS. After 4 months of follow-up the mean number of AF episodes/patient were 2.8±2.9 and were reduced to 0.7±1 (p=0.001) in the follow-up period II. In the follow-up period II a lower number of MS episodes/patient were observed than in the follow-up period I (5.8±7.4 vs 23.8±33.4, p=0.01). This was associated with an higher percentage of AP time (84.4±15.8 vs 35.3 ±21, p<0.001). A significant negative linear correlation (r= 0.7, p<0.001) was found between the log of MS data and the percent time of AP, implying an exponential decay relationship with the original data.

CONCLUSIONS. Increasing the percent time of AP reduces AF recurrences as measured by the number of MS episodes. Moreover, the most of this beneficial reduction is in effect with just a relatively short time of AP.

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