Catheter ablation of idiopathic outflow tract ventricular arrhythmias with low intraprocedural burden guided by pace mapping

Background: There are limited data comparing ablation outcomes in patients with low intraprocedural burden of ventricular arrhythmias (VA) undergoing a pace mapping (PM)-guided strategy vs those with high burden guided by standard activation mapping strategy (non-PM).

Objective: We sought to determine if catheter ablation-guided by PM of low-intraprocedural-burden idiopathic outflow tract VA would be noninferior compared to non-PM-guided ablation.

Methods: Outcomes of catheter ablation of idiopathic outflow tract VA in 22 patients with a low burden of intraprocedural VA using PM-guided ablation were compared to 44 patients with a high burden of intraprocedural VA undergoing ablation using standard techniques.

Results: Sixty-six patients were included (age 46.5 ± 14.8 years; 68% female, left ventricular ejection fraction 59% ± 5%). Within the PM group, 24-hour preprocedure premature ventricular complex (PVC) burden was 9.5% (interquartile range [IQR] 4%-13.8%), number of pace maps 33.6 ± 18.5, surface area of ≥95% pace map correlation 1.9 ± 1.2 cm², with best pace map correlation 96% (IQR 92%-97%). Within the non-PM group, 24-hour preprocedure PVC burden was 13.5% (IQR 6.6%-30%), earliest activation time -33.7 ± 9.9 ms. Procedural duration, general anesthesia administration, fluoroscopy dose, and complications were all comparable. Following final procedure, 24-hour VA burden (PM 0% [IQR 0-2.4%] vs non-PM 0% [IQR 0-4.2%], P = .98), along with VA-free survival at 6-month follow-up (PM 77% vs non-PM 71%, P = .77), were both comparable.

Conclusion: In patients with low intraprocedural burden of outflow tract VA, PM-guided catheter ablation can accurately identify the VA site of origin, leading to outcomes comparable to those achieved with standard ablation techniques.