Optimal Force–Time Integral for Pulmonary Vein Isolation According to Anatomical Wall Thickness Under the Ablation Line

Abstract

Background--Low contact force and force-time integral (FTI) during catheter ablation are associated with ineffective lesion formation, whereas excessively high contact force and FTI may increase the risk of complications. We sought to evaluate the optimal FTI for pulmonary vein (PV) isolation based on atrial wall thickness under the ablation line.

Prospective use of Ablation Index targets improves clinical outcomes following ablation for atrial fibrillation

“…While this value may well be required in some regions of the LA, there is concern that it may be excessive in more thin‐walled areas, increasing the risk of damage to adjacent structures such as the esophagus. A recent study has demonstrated that the optimal FTI value for achieving an effective lesion is dependent on the underlying atrial wall thickness, and we have previously reported that FTI values of only 230gs were associated with no reconnection of posterior/inferior segments at repeat electrophysiology study …”

Cavotricuspid isthmus ablation using ablation index in typical right atrial flutter

“…In a study in which minimum AI value was ≥480 for anterior segments and ≥370 for posterior segments of the left atrium, no late pulmonary vein reconnection was apparent at 2 months post procedure. Therefore, based on the latter values, we set different AI values (500 for anterior segments and 400 for posterior segments) according to the thickness of the anterior and posterior portions of the CTI . Regional comparison in our study showed that for anterior segments of CTI, the mean ablation time, impedance drop, FTI and AI value of each VisiTag point were higher in the AI group than in the CF group under similar mean CF and power for the two groups which led to larger lesion for the AI group.…”

“…Therefore, proper ablation can help to ensure effectiveness and reduce complications. Although CF and FTI, that is, the product of mean CF times energy application duration have been introduced as useful tools to evaluate ablation lesion efficacy during pulmonary vein isolation, they still have significant limitations because lesion creation is dependent upon catheter‐tissue contact, duration of energy application and power. Compared to CF and FTI, AI which combines the latter three factors in a weighted equation has been shown to better correlate with lesion depth in an animal model .…”

Optimal lesion size index to prevent conduction gap during pulmonary vein isolation

“…Volume data were reconstructed into axial images (slice thickness of 0.9 mm) and transferred to a workstation for postprocessing (Ziostation2; Ziosoft, Tokyo, Japan). For each PV, we divided the PV antrum into eight segments under the ablation line, and quantitative measurements for each region were performed, as reported previously …”