Abstract 3508: Factors Affecting Error in Integration of Electroanatomic Mapping with Computed Tomographic and Magnetic Resonance Imaging During Catheter Ablation of Atrial Fibrillation
Background: Integration of 3-D electroanatomic mapping with CT and MR imaging can facilitate catheter ablation of atrial fibrillation (AF), but is critically dependent on obtaining accurate image integration. We examined the effect of patient- and technique-related factors on integration accuracy of electroanatomic maps with CT and MR images of the left atrium and aorta.
Methods: 61 patients undergoing catheter-based AF ablation procedures were included. All patients underwent cardiac CT (n=11) or MR (n=50) imaging, with subsequent integration with real-time electroanatomic mapping of the aorta and left atrium (LA). CARTO-Merge software (Biosense-Webster) was used to calculate the overall average accuracy of integration of electroanatomic points with the CT and MR-derived reconstructions of the LA and aorta.
Results: There was a significant correlation between LA size assessed by electroanatomic mapping (104 ± 34 ml) and average integration error (1.9 ± 0.6 mm) (r=0.29, p=0.025, Figure⇓). There was also greater integration error for patients with LA volume ≥ 100 ml (n=32, average integration error 2.1 ± 0.6 mm) versus < 100 ml (n=29, average integration error 1.7 ± 0.4 mm) (p=0.004). In contrast, there was no significant association between average integration error and paroxysmal versus persistent AF, left ventricular ejection fraction, days from imaging to electroanatomic mapping, or for images derived from CT versus MR.
Conclusions: Patients with larger LA volume may be prone to greater error during integration of electroanatomic mapping with CT and MR imaging. Strategies to reduce integration error may be especially useful in patients with large LA volume.