Abstract 13721: The Relation Between Atrial and Ventricular Ectopic Beats, Biventricular Pacing Percentage, and Reverse Remodeling
Background: A high percentage of biventricular (BIV) pacing is required for optimal outcome in patients treated with cardiac resynchronization therapy (CRT) but the influence of ectopic beats on the success of BIV pacing has not been established.
Methods: In the MADIT-CRT trial all patients who received a CRT-D (N=1089) had a pre-implantation 24-h Holter recording performed. The average percentage of BIV pacing during the trial was acquired through device interrogations. Using logistic regression we estimated the influence of atrial and ventricular ectopic beats on the percentage BIV pacing. Reverse remodeling was measured as reductions in left ventricular end systolic volumes at one year.
Results: Pre-implantation atrial and ventricular ectopic beats occurred in most patients, 94% and 99%, respectively. The mean number of ectopic beats were 539 (±2236) for atrial and 2999 (±5187) for ventricular ectopics during an average of 23.2(±1.7) hours of Holter recordings. Combined, the ectopy accounted for a mean 3.2% (±5.5%) percent of all beats. Patients who a had a high percentage of ectopic beats were more likely to receive < 97% BIV pacing, whereas patients with a lower percentage of ectopic beats were more likely to receive ≥97 % BIV pacing (Figure).
The probability of subsequent high BIV pacing (≥97%) was reduced by 14% (OR: 0.86 CI: 0.83-0.89, p<0.001) per unit increase in percent ectopy of all beats. Patients who had more than 1% ectopy were 80% less likely to receive high BIV pacing compared to those with less than 1% ectopy (OR: 0.20, CI: 0.14-0.27,p <0.001). Patients who had less than 1% ectopy also had significantly increased reverse remodeling (% reduction: 35.7±15.1) compared to patients with 1% or more ectopic beats (% reduction: 29.2±15.0), p<0.001.
Conclusion: Relatively low frequencies of atrial and ventricular ectopy reduce the success of biventricular pacing. Pre-implantation Holter recording can identify patients who are less likely to have optimal BIV pacing.
- © 2013 by American Heart Association, Inc.