PO-02-008 OPTIMIZATION OF ADAPTIVE CRT NONRESPONDERS USING ELECTRICAL DYSSYNCHRONY MAPPING

Abstract

We have previously demonstrated that optimization of CRT nonresponders using electrical dyssynchrony mapping (EDM) significantly improves LV size and systolic function. Adaptive CRT (aCRT) pacing algorithm improves heart function and clinical outcomes in select CRT patients. However whether aCRT nonresponders can be improved with optimization is unknown. To assess the effects of optimization (using a novel measure of electrical wavefront fusion and cancellation called EDM) on left ventricular (LV) size and systolic function in CRT nonresponders programmed using aCRT. We studied 28 nonresponder CRT patients programmed using aCRT 3.0 ± 3.3 years post-implantation. The area under the curves (AUC) between 9 anterior/9 posterior electrograms was measured at multiple combinations of atrial-ventricular and ventricular-ventricular delays (AVD, VVD). Electrical dyssynchrony was quantified by cardiac resynchronization index (CRI), calculated as % change in AUC between all combinations of anterior and posterior electrograms, compared to native (CRI values 0-100%). EDM with atrial-to-LV-paced (A-LVp) interval on the x-axis and atrial-to-RV-paced (A-RVp) interval on the y-axis depicted CRI over the wide range of settings tested. Echocardiograms with speckle-tracking were analyzed in a blinded fashion pre-optimization and 4-6 months post-optimization. EDM (Figure) of nonresponder programmed by aCRT algorithm to LV-only pacing at 130 ms AVD (CRI 58%) and optimized to LV-only pacing at 90 ms AVD (CRI 93%). EF improved from 33% to 40%. Table shows significant improvements in CRI (43.5%), LV ejection fraction (5.4%), LVESV (12.8 ml), LV global transverse (1.4%) and longitudinal strain (2.5%) in the patient cohort. Nonresponders programmed by the aCRT algorithm are 46% electrically resynchronized at baseline and improve to 90% with optimization using EDM. CRT optimization using a novel EDM technology significantly improves electrical synchrony, LVESV and LV systolic function. This methodology provides a non-invasive, practical approach to quantifying electrical dyssynchrony over a wide range of AVDs/VVDs and then optimizing aCRT nonresponders.Tabled 1Dyssynchrony and echo variables in aCRT nonresponders pre- and post-optimizationVariablePre-optimizationPost-optimizationp-valueCRI (%)46.4 ± 25.689.9 ± 11.7≤ 0.001LVEF (%)31.9 ± 4.637.3 ± 6.0≤ 0.001LVEDV (ml)154.9 ± 56.6146.3 ± 51.60.133LVESV (ml)106.1 ± 41.893.3 ± 38.20.024Longitudinal strain (%)-12.0 ± 2.2-13.4 ± 2.60.017Transverse strain (%)17.9 ± 4.120.4 ± 5.30.010 Open table in a new tab