Significance of coherent mapping in unveiling slow conduction zones of ventricular tachycardia substrate in ischemic cardiomyopathy.

BACKGROUND

Identifying slow conduction zones (SCZs) within the ventricular tachycardia (VT) substrate remains a major challenge in ischemic cardiomyopathy (ICM). We aimed to evaluate the role of coherent mapping (CM) in identifying SCZs within low-voltage areas (LVAs) in VT substrate mapping and assess its impact on VT ablation outcomes.

METHODS

This retrospective study included 32 patients with ICM who underwent ablation for recurrent VT. CM-SCZs were compared with traditional substrate markers, including late potentials (LPs), local abnormal ventricular activities (LAVAs), and ILAM-based deceleration zones (DZs). Ablation strategies targeting CM-SCZs were analyzed in relation to procedural and clinical outcomes, including VT recurrence and total radiofrequency (RF) ablation time.

RESULTS

CM-SCZs were consistently identified adjacent to LVAs in all cases, with a mean area of 5.2 ± 2.3 cm2. CM-SCZs colocalized with ILAM-based DZs in 56.3% of cases and overlapped with LPs and LAVAs in selected patients. Among patients who remained free from VT recurrence, total RF ablation time was significantly longer (938 ± 354 vs. 380 ± 448 s, p = 0.03), suggesting that more extensive substrate modification played a role in arrhythmia suppression. Furthermore, patients with VT recurrence had lower post-ablation non-inducibility rates (50% vs. 91.6%, p = 0.02).

CONCLUSION

CM improves the identification of SCZ within the VT substrate and enhances substrate-based ablation strategies. Incorporating CM-SCZs into VT ablation protocols may improve procedural success and reduce arrhythmia recurrence. Future studies should validate these findings and explore role of CM in broader patient populations.