Sinus rhythm late activation zones as a target for improving ventricular tachycardia ablation outcomes

Ventricular tachycardia (VT) ablation is a critical intervention for patients with ischemic heart disease and has demonstrated to improve patient’s prognosis. Although there is some evidence regarding the best way to identify the substrate for ablation, there is limited data on the clinical impact of having the latest activation regions in sinus rhythm (SR) as the main target for the VT ablation procedure.

This study aimed to evaluate whether applying radiofrequency to areas corresponding to the latest activation in SR (as per LAT histogram analysis) and associated with low voltage mapping is linked to a lower recurrence rate of VT/VF or appropriate ICD therapies in the medium term compared to cases treated solely based on voltage and VT activation maps.

We conducted a retrospective single-centre study on prospectively collected data from patients who underwent ischemic VT ablation between January 2022 and September 2024. Patients were classified into two groups based on the correlation of late activation areas in SR with low-voltage regions: Group 1 (correlation between both areas and with RF application) and Group 2 (correlation but without RF application).

A total of 32 patients, 96% male, 100% with ischemic heart disease and 9% with an associated primary cardiomyopathy were included, with a mean age of 65 ± 11 years and mean LVEF 35 ± 11%. Successful ablation, as per non-inducible VT at the end of the procedure was achieved in 93% of all the cases. During a mean follow-up of 1.42 ± 0.85 years, a total of 8 patients had VT/FV recurrence, namely 4 patients in group 1 (4/25; 16%) and 4 patients in group 2 (4/7; 57%), indicating a higher recurrence in the latter group, reaching statistical significance χ2 (1, N=32) = 4.94, p = 0.026

Targeting late activation areas in sinus rhythm corresponding to low voltage regions results in a significantly lower recurrence rate of VT events or ICD therapies when compared to targeting based solely on voltage and VT activation maps. Further studies are warranted to validate these findings and explore their implications for clinical practice.