Aims

Force–Time Integral (FTI) is used as a marker of ablation lesion quality during pulmonary vein isolation (PVI). Only a single FTI target value has been suggested despite regional variation in left atrial wall thickness. We aimed to study the minimum FTI-values to determine a scar on cardiac-MRI 3 months post-ablation.

Methods and results

Ten consecutive patients with atrial fibrillation underwent contact force-guided PVI. The minimum and mean FTI values for each segment were identified according to a 8-segment model. All patients underwent cardiac-MRI study at 3 months, regardless of symptoms, to identify myocardium lesions. Baseline characteristics were by all patients similar. The mean age was 64 ± 10 years, 60% male, hypertension diagnosed by all patients in the study.

The minimum FTI values needed to determine a lesion in each PV segment are represented in table 1 (LSPV, left superior vein; LIPV left inferior vein; RSPV, right superior vein; RIPV, right inferior vein).

Conclusion

There are different minimum FTI values for each PV segment, as shown in cardiac MRI images 3 months post-ablation. Higher FTI values are required for anterior left pulmonary veins, posterior RSPV and anterior RIPV comparing to the corresponding anterior/posterior segments.  

Keywords

Atrial fibrillation; FTI (force time integral); PVI (pulmonary vein isolation); Catheter ablation. 


Picture 1.  PA-View, blue-Healthy tissue, red/white- lesion (scar).