The HD-grid multipolar mapping catheter has emerged as an invaluable tool for greater effectiveness of pulmonary vein isolation (PVI). In the cases described below, fractionated signals seen with the HD-grid catheter at the LAA and LSPV junction were ablated. These signals likely would not be visualized with conventional catheters and may cause recurrences due to incomplete PVI. The directional sensitivity limitations of bipolar electrogram recordings and the unique anatomy of the LAA-LSPV ridge further contribute to the challenge of evaluating pulmonary vein isolation. The HD-grid catheter’s ability to record bipoles parallel and perpendicular to the catheter splines and its high-density mapping capabilities provide a superior means of identifying gaps in ablation and detecting the low-voltage isthmus. Furthermore, factors such as ablation quality, catheter stability, and the thickness of the LAA-LSPV ridge influence the presence of fractionated signals and the success of PVI. Incorporating pre-procedure imaging modalities such as CT or MRI and real-time intracardiac echocardiography could enhance the tailored approach to address these challenges. Future developments in HD-grid technology, including contact force measurement during mapping, may offer additional insights into the nature of these signals. This case series highlights the significance of utilizing the HD-grid catheter for detailed interrogation of the LAA-LSPV ridge, ultimately leading to more effective PVI and improved outcomes in patients with afib

Purpose: A stable contact force (CF) is correlated with more effective radiofrequency ablation (RFA) lesions and long-term procedural outcomes. Efforts to improve catheter stability include jet ventilation, pacing, steerable sheaths, and CF sensing ablation catheters. This study compares CF stability and effective RF lesions between two commercially available steerable sheaths. Methods: Thirty patients underwent first time RFA at a single center using the Agilis NxT or SureFlex Steerable Sheath. High power short duration RFA was utilized targeting a 10Ω drop. Sheath performance was assessed for the entire procedure and around each pulmonary vein (PV) in terms of mean CF, CF variability, RF time per lesion, and inefficient contact lesions (defined as lesions with CF < 5g for at least 10% of the RF delivery time). Results: Operator-targeted mean CF was achieved using both sheaths; however, overall CF variability was 12.8% lower using the SureFlex sheath (p = 0.08). CF variability was generally 16% greater in the right PVs than the left PVs (p = 0.001), but trended lower with the SureFlex sheath. There were 8% more inefficient contact lesions using Agilis as compared to SureFlex (p = 0.035), especially in the right inferior PV (p = 0.009). RF time per lesion was on average 12% (1.4s) shorter using SureFlex than Agilis (p < 0.05). Conclusion: Choice of steerable sheath may affect catheter stability and potential lesion quality, especially in the right PVs.