PO-02-009 LEAD REVISION AND OPTIMIZATION OF CRT NONRESPONDERS USING ELECTRICAL DYSSYNCHRONY MAPPING

Abstract

Identification and treatment of CRT nonresponders who have poor LV lead position is a significant clinical problem. To describe how a new technology for measuring electrical dyssynchrony can be used to identify CRT patients with poor LV lead position and optimize their device programming with or without LV lead revision. An ECG system of 9 anterior/9 posterior leads was used to quantify a novel measure of electrical dyssynchrony called cardiac resynchronization index (CRI), defined as % change in area under the curve between all combinations of anterior and posterior electrodes as compared to native (CRT off). An electrical dyssynchrony map (EDM) was used to graphically display CRI values at multiple different atrial-ventricular delays (AVD) and ventricular-ventricular delays (VVD). Poor LV lead position was defined as optimal CRI (CRIopt) < 90% or need for VVD > -80 ms (LV ahead) to achieve CRIopt. We studied 19 CRT nonresponder patients with poor LV lead position based on EDM criteria. Mean CRI was 31.8±21.5%. LV lead location was anterior (n=8), apical (n=6) and posterior/lateral (n=5). Figure 1 shows an EDM of a patient before and after lead revision. Initial lead was an anterior epicardial lead. CRIopt was at VVD of -90 ms (LV-paced ahead) and EF did not improve with optimization. After placement of a lateral LV lead, VVD optimization of -30 ms resulted in an improvement in EF from 25% to 33%. Fifteen patients were programmed to CRIopt. Four patients were optimized to LV-only pacing at the optimal AVD and 11 were programmed biventricular with mean VVD -61±25 ms (LV-paced ahead). Five of these patients had minimal or no improvement with optimization. and underwent lead revision. Four patients did not have a device setting with a substantially improved CRI and 2 of 4 underwent LV lead revision. All 7 patients with LV lead revision had repeat optimization after lead revision. LV ejection fraction (EF) measured 4-6 months post-optimization improved significantly (p ≤ 0.05) from 29.1 ± 7.1% to 33.5 ± 5.8% in the 17 patients optimized by reprogramming and/or lead revision. EDM is a noninvasive, practical methodology that can be used to identify CRT nonresponder patients with poor LV lead position, determine whether lead revision may be of benefit, and optimize device programming before and/or after lead revision. This clinical approach results in a significant improvement in EF of 4.4%.