Clinical Electrophysiology -> Ventricular Arrhythmias -> Mapping & Imaging D-PO06 - Poster Session VI (ID 26) Poster

D-PO06-051 - Optimal Electrode Configuration For Near-field Electrogram Characterization And Gap Detection (ID 683)


Background: Effect of electrode size on EGMs is not fully understood.
Objective: To elucidate this point and investigate the optimal configuration of electrode size and interelectrode spacing.
Methods: Dedicated probes with different electrode size and inter-electrode spacing were manually placed epicardially (Figure 1). In Step 1, EGMs were compared between 3 mini-electrodes (0.1mm, 0.2mm, and 0.5mm) with 3mm inter-electrode spacing. Gap/scar ratio (G/S-ratio) and non-fat/fat ratio (NF/F-ratio) were compared with 0.2mm-electrode/0.1mm-spacing as a reference. In Step 2, the catheter configuration to provide the best G/S-ratio and N/F-ratio was examined.
Results: Step 1 demonstrated that both unipolar and bipolar voltages increased as the electrode size increased (P<0.0001) and the G/S-ratio and NF/F-ratio were significantly larger with smaller spacing (0.2mm electrode and 0.1mm). In Step 2, comparison of mini-electrodes of 0.2mm and 0.5mm and inter-electrode spacing of 0.1mm, 0.3mm, and 0.5mm showed that 0.1mm inter-electrode spacing provided the highest G/S-ratio and NF/F-ratio (Figure 2). Finally, electrode sizes of 0.2mm, 0.3mm, 0.4mm, and 0.5mm with 0.1mm inter-electrode spacing were compared, and demonstrated that the difference in G/S-ratio and N/F-ratio was not always significant between each catheter configuration. However, a notable difference was shown between the smaller (0.2mm and 0.3mm) vs. larger (0.4mm and 0.5mm) electrodes (P<0.0001) (Figure 3).
Conclusion: Electrode size affects both unipolar and bipolar voltages. An electrode size of 0.2mm or 0.3mm with 0.1mm inter-electrode spacing may be best improving gap detection and reducing far-field effect.