Abstract 3284: Effect of Rate Control During Atrial Fibrillation on the Amount of Cardiac Resynchronization Pacing
# Introduction: AF with poor control of the ventricular (V) rate is known to negatively impact cardiac resynchronization therapy (CRT). However, the relationship of the V rate to the amount of CRT pacing has not been quantified.
Objective: To determine the relationship between rate control and the amount of CRT pacing.
Methods: A retrospective analysis was conducted on patients (pts) enrolled in the InSync ICD Registry. Pts were included if they had a cumulative device detected AT/AF ≥ 48 hours and at least 30 days of data on V pacing (VP) in sinus rhythm (SR) and AF as a function of heart rate. Pts were grouped into 4 quartiles based on their amount of time with V. rates ≥ 90 bpm during AF. The percent of time with VP during AF was then compared between the pt sub-groups.
Results: There were 180 pts that had at least 30 days with histogram data. Of those, 55 pts had ≥ 48 hours of AT/AF. Mean follow-up for these 55 pts was 397 days, mean age was 71 years, and mean LVEF was 22 ± 7%. On average, these 55 pts were in AF 46 ± 41% of the time. The figure⇓ shows that pts in the upper quartile (> 25.2% of time at V. rates ≥ 90 bpm) had significantly lower CRT pacing than the other quartiles (pair-wise comparison Bonferroni adjusted p < 0.008). The median pacing percent was only 69.5% in the pts with > 25.2% of their time in AF at V. rates ≥ 90 bpm.
ICD diagnostics may be useful for assessing rate control and its impact on CRT pacing.
Pts in AF with over 25% of their time at V. rates ≥ 90 bpm are likely to experience significant reductions in CRT pacing.
Clinical Implication: Vigilant monitoring of V rate control during AF could be useful for making interventions (e.g., medications, AV ablation, CRT programming) to maximize CRT. #