Abstract 18119: Lesion Formation in Atrial Fibrillation Ablation: Integration of Force Sensing Catheter With LGE-MRI
Introduction: Contact force (CF) is a critical factor in lesion formation during radiofrequency (RF) atrial fibrillation (AF) ablation. Late gadolinium enhancement magnetic resonance imaging (LGE-MRI) is an effective tool for assessment of lesion formation and detection of acute esophageal injury.
Methods: LGE-MRIs were obtained prior, within 24 hours of, and at 3 months after first AF ablation in 34 patients. AF ablation was performed with a CF sensing SmartTouch™ ablation catheter and ablation parameters (force, duration, force-time integral (FTI)) for each registered ablation point were collected using the Visitag module of CARTO3. The minimum CF resulting in permanent lesions by LGE-MRI was determined. Esophageal enhancement was classified as mild, moderate and severe. The mean CF threshold resulting in esophageal enhancement was determined. The main steps of data analysis are shown in Figure 1B.
Results: A total of 5557 registered ablation points were analyzed (Figure 1A). The average duration of RF ablation was significant between ablation points with and without associated LGE-MRI detected scar (5.6±3.2 s vs 5.9±3.7 s, p=0.007). A CF greater than 11.5 grams was more likely to create a permanent lesion than forces less than 11.5 grams (11.5±5.4 g vs. 10.7±5.4 g, p<0.001). Similarly, an FTI greater than 67.4 gs was more likely to create permanent lesions (67.4±55.7 gs vs. 60.4±48 gs, p< 0.001). Ablation earlier in the procedure was more likely to result in permanent lesion formation (308±775 s vs 540±1513 s, p< 0.001). The mean CF in areas of esophageal enhancement was greater than areas without (14.1±6.5 g vs. 11.8±4.7 g, p=0.002, n=9 patients).
Conclusions: A minimum CF of 11.5 grams and earlier time during the procedure predicts permanent RF lesion formation. The latter suggest that edema formation may interfere with the ability to create permanent lesions later in the procedure. CF greater than 14 g over esophagus may lead to esophageal injury.
Author Disclosures: M.G. Chelu: Research Grant; Modest; Amiigo. Research Grant; Significant; Biotronik. A. Morris: None. E.G. Kholmovski: None. G. Kaur: None. N.F. Marrouche: Speakers Bureau; Modest; Medtronic. Honoraria; Modest; Biosense Webster, Boston Scientific. Ownership Interest; Modest; St Jude. Ownership Interest; Significant; Marrek, Cardiac Designs, Preventice.
- © 2016 by American Heart Association, Inc.