Role of Octaspline Multielectrode Catheter and Unipolar Reference Location for Premature Ventricular Contraction Ablation

ABSTRACT Background An accurate local activation time (LAT) map is essential during premature ventricular contraction (PVC) ablation. The aim of this study was to evaluate whether the use of a novel octaspline multielectrode catheter, with and without the use of a catheter‐embedded unipolar reference, improves LAT mapping during PVC ablation compared to a pre‐existing pentaspline mapping catheter. Methods This study prospectively assessed 10 consecutive patients referred for PVC ablation from January to June 2023. Three 12‐min LAT maps were performed in each patient using three different strategies: pentaspline catheter + unipolar reference in the inferior vena cava (IVC) versus octaspline catheter + unipolar in the IVC versus octaspline catheter + unipolar embedded in the mapping catheter. Acute procedural and midterm endpoints were assessed. Results The use of an octaspline catheter increased the number of total LAT points (1010 ± 451 vs. 397 ± 213, p = 0.001), LAT points near the successful RF ablation site (118 ± 105 vs. 21 ± 19, p = 0.010) and electrograms (EGM) per PVC (23 ± 21 vs. 7 ± 3, p = 0.032), while reducing mapping duration (65 ± 41 EGM/min vs. 21 ± 8 EGM/min, p = 0.003). However, signal resolution was not superior to that obtained with the pentaspline catheter, with similar bipolar ( p = 0.505) and unipolar ( p = 0.176) voltages, an increased bipolar signal duration ( p = 0.003) and a reduction in the unipolar signal duration ( p = 0.013). Use of a catheter‐embedded unipolar reference led to shorter unipolar signal duration (76 ± 34 ms vs. 142 ± 29 ms, p < 0.001), and provided an earlier unipolar signal deflection to QRS onset (−24 ± 16 ms vs. −19 ± 11 ms, p = 0.006) and earlier −dV/dT signal annotation (−12 ± 10 ms vs. −7 ± 9 ms, p < 0.001). This subsequently led to a shorter distance from the earliest LAT to successful RF site ( p = 0.014). No significant differences between multielectrode mapping catheters were seen regarding catheter‐induced ectopy rate ( p = 0.703). Conclusions The use of an octaspline catheter combined with an embedded unipolar reference may associate with faster, more detailed and accurate activation mapping in the setting of PVC ablation.