Abstract 2509: Significant Increase in LV Function with Multisite LV Endocardial Pacing Guided By 3D Activation Map for LV Resynchronization
Background: We have previously demonstrated in a heart failure (HF) dog model the potential benefit of single site endocardial pacing over epicardial pacing via the Coronary sinus (CS). However, it is not clear if additional improvement in LV function can be achieved with multi site LV endocardial activation.
Methods: LV synchronization was evaluated by 2D strain using automated function imaging (GE Health Care) in 7 HF mongrel dogs. HF was induced by rapid RV apical (RVA) pacing for at least 21 days with prior AV nodal ablation. Pacing electrodes were placed in the RVA and CS. Two endocardial LV leads were placed via atrial transeptal approach under fluoroscopy. The first was placed in the posterolateral wall (PLE) adjacent to the CS pacing site with the second positioned in the latest activation site (LAE) as determined by mapping with 3D mapping system while pacing the RVA + PLE. Heart rate was set constant in all experiments (100bpm) and maintained at 170 bpm between data acquisition.
Results: CRT from the RVA with two LV endocardial leads was superior to RVA + PLE or RVA + CS in reducing the number of delayed longitudinal contraction segments (DLC) (fig⇓). When compared to RVA + CS CRT, global average LV strain improved with RVA + PLE and with RVA + PLE + LAE by 29.3% (SE = 8.59, p = 0.02) and 39.2% (SE = 2.86, p = 0.003) respectively.
Conclusion: Further improvement in LV synchronization and global function can be achieved with multi LV endocardial pacing guided by electrical mapping. These data should stimulate the interest for a leadless CRT system.