Prevention of Atrial Arrhythmias during DDD Pacing by Atrial Overdrive

Abstract

We evaluated the effect of atrial overdrive on the incidence of atrial arrhythmias (AA) in 22 patients (67 +/- 9 years, 7 women, 15 men) with Chorus 6234 DDD pacemakers. Atrial overdrive was defined as a programmed paced rate 10 ppm faster than the mean ventricular rate stored for the last 24-hour period in the pacemaker memory. The protocol consisted of three phases of 1 month each. Phase I: observation after discontinuation of antiarrhythmic therapy. Phase II: arrhythmia analysis using the pacemaker memory after programming the lower rate to 55 ppm. The fallback function and histogram data were used to document the number and maximal duration of AA episodes as well as the total AA time in a month. Phase III: atrial overdrive. The mean ventricular heart rate was 65 +/- 4 beats/min before atrial overdrive versus 75 +/- 5 with atrial overdrive (P = 0.02). At the end of phase II, all patients presented with AA episodes (mean number per patient: 42 +/- 78 in one month). In phase III (with atrial overdrive), 14 (64.6%) patients had no recorded AA (group A). In the other eight patients with persistent AA episodes in phase III (group B), there was a significant reduction in the number of AA episodes (90 +/- 106 in phase II vs 38 +/- 87 in phase III; P = 0.01), their total duration (166 +/- 115 in phase II vs 92 +/- 134 hours in phase III; P = 0.03) and their maximal duration (121 +/- 103 in phase II vs 85 +/- 89 min; P = 0.04). Our short-term data suggest that atrial overdrive prevents or reduces AA episodes and demonstrate the feasibility and need of long-term studies to determine whether this benefit is sustained.

Implanted Devices and Atrial Fibrillation

“…Both these options, although cheap and easy to perform in an out-of-hospital setting, are not very effective. Reprogramming a lower rate 10 bpm faster than 24 hours mean heart rate prevented AF recurrence in approximately 60% of patients over a 30-day follow up [34]. In another study, while atrial pacing vastly reduced total premature atrial beats from 3.8 per hour to 0.5 per hour, no difference was found in AF recurrence prevalence or time to first recurrence between paced and not paced patients [35].…”

Atrial fibrillation in the elderly

“…Dual-chamber pacing reduces the incidence of AF and the rate of progression to chronic AF when compared to ventricular pacing alone [35]. Dual-site atrial pacing (ie, from the right atrium and the coronary sinus [36]) and high-rate atrial pacing to suppress native sinus and atrial premature beats [37] have shown variable results. These options may be considered in patients with AF who have standard indications for pacing.…”

Diretrizes para Avaliação e Tratamento de Pacientes com Arritmias Cardíacas

“…Sparks e cols., demonstraram que a estimulação atrial a longo prazo promove o remodelamento atrial, um importante componente na eletrogênese da FA 63 . Estudos randomizados, entretanto, são necessários para que esses achados sejam confirmados e considerados definitivos [64][65][66][67] . Pequenos estudos não-randomizados, sugerem que a estimulação multi-sítio pode ser útil em pacientes com FA paroxística e importante distúrbio de condução interatrial 56,57,68 .…”