Background
The ablation index (AI) is reported to be useful for a durable pulmonary vein isolation (PVI). However, there have been no studies investigating the relationship between the power, contact force (CF), AI, and steam pops.
Methods
Using an in vitro model, ablation energy was delivered until a steam pop occurred and the time to the steam pop and AI when the steam pop occurred were measured. The experiment was performed with a combination of various powers (20, 30, 40, and 50 W) and contact forces (CFs) (10, 30, and 50 g) 20 times for each setting. The analysis consisted of two protocols. The first protocol was a comparison between the ablation power and several parameters under the same CF (10, 30, and 50 g). The second protocol was a comparison between the CF and several parameters under the same power (20, 30, 40, and 50 W). The correlation between the lesion formation and ablation parameters was evaluated.
Results
The AI value when steam pops occurred varied depending on the ablation settings. All AI median values were <500 under an ablation power of 50 W. On other hand, the median ablation time up to the steam pop was more than 46 seconds, but all median values of the AI were more than 550 under an ablation with 20 W.
Conclusions
The AI cannot predict steam pops. A low power and long duration ablation could obtain a high AI value. However, high‐power ablation could not obtain a high AI value because of an early occurrence of steam pops.
A B S T R A C TBackground: Left atrial appendage closure (LAAC) has been suggested as an alternative to anticoagulation in non-valvular atrial fibrillation (AF). The present study aimed to compare a LAmbre LAA occluder system [Lifetech Scientific (Shenzhen) Co. Ltd., Shenzhen, China] with the most investigated Amulet (St. Jude Medical Inc., St. Paul, MN, USA) and Watchman (Boston Scientific, Plymouth, MN, USA) devices in terms of peri-procedural and short-term outcomes. Methods: This is a prospective observational study. Results: Overall, 140 patients (50 female, mean age 76.2 AE 8.4 years) were consecutively enrolled. Mean CHA2DS2-VASc score was 3.8 AE 1.5, and mean HAS-BLED score was 3.9 AE 1.1. Baseline clinical characteristics were comparable between the three groups (LAmbre, n = 30; Amulet, n = 74; Watchman, n = 36); the LAmbre group had significantly more patients with complicated LAA morphology (p = 0.006). The implant success rate was 100% in LAmbre, 99% in Amulet, and 100% in Watchman group (p = 0.638). The number of device repositions was not significantly different between groups (0.7 AE 1.1 in LAmbre, 1.0 AE 2.0 in Amulet, and 1.4 AE 1.8 in Watchman group, p = 0.345). Fluoroscopic and procedural times were similar between groups. Major peri-procedural adverse events did not differ between groups (0% vs. 0% vs. 2.8%, p = 0.233). Six months' follow-up showed good device stability and patients' clinical condition in all groups. Conclusion: LAmbre, Amulet, and Watchman exhibit remarkable implant success rate, low risk of periprocedural adverse events, and good clinical outcomes.
LAA isolation by Maze-like substrate modification may be considered a viable option for PVI non-responders. It offers a reproducible approach with an unambiguous procedural endpoint and leads to a favorable clinical outcome. However, extensive LA ablation increased the risk of tamponade. Consecutive LAA occlusion may offer a nonpharmacologic strategy to overcome the high thromboembolic risk associated with absent mechanical LAA contraction.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.