Advertisement

CE-520-02 ELECTRO-ANATOMIC REPOLARIZATION MAPPING WITH ORTHOGONAL BIPOLES AND MULTI-ELECTRODE ARRAYS: THE NEXT FRONTIER IN CATHETER TECHNOLOGY

      Background

      Sites of steep repolarization gradients have been attributed to arrhythmogenesis. However, identifying these regions during clinical mapping has not materialized. Activation interval recovery (ARI), monophasic action potential (MAP) and optical mapping are not practical for clinical usage during ablation procedure. Clinical repolarization mapping has not been practically viable largely due to instrumentation and signal processing challenges. We developed here a repolarization mapping technology from orthogonal bipole derived vector loops in multielectrode array and the time projection of the repolarization loop electrogram (loop derived repolarization-optimized egm, (rEGM), for assessment of repolarization on mapping arrays.

      Objective

      We hypothesised that rEGM provides vector derived integrated action potential duration (APDV) that correlates with local repolarization assessed by optical mapping.

      Methods

      Simultaneous optical mapping and epicardial mapping with Abbott AdvisorTM HD Grid was performed in 4 rabbit Langendorff experiments. Unipolar egms from 4 electrodes forming a square in the middle of the grid were recorded and intra-cardiac vectorcardiogram loops computed from orthogonal derived bipoles. rEGM was obtained by projecting the repolarization loop along its maximum axis. Epicardial waves propagating in different direction and pinacidil was added to alter APD. APDV was measured from the onset of QRS to baseline return of rEGM. rEGM derived APDV were compared with fluorescence signals and optical APD90 measured in the middle of the electrode clique.

      Results

      A total of 61 pairs of APDV measurements were performed. Baseline conditions showed an VAPD average of 142ms versus APD90 of 151ms. After 20uM addition of pinacidil ARI and APD were reduced to 68ms and 89ms respectively. Linear correlation between APDV and APD90 showed a R2 of 0.7134 and a slope of 0.9540.