Displacement of the target ablation site and ventricles during premature ventricular contractions: relevance for radiofrequency catheter ablation.

Background: During premature ventricular contractions (PVCs), a spatial displacement of the ventricles and the target ablation site with respect to the sinus rhythm (SR) position is observed during mapping and ablation.
Objectives: To analyze this displacement and its relevance for image integration and PVC ablation.
Methods: The electroanatomical activation maps (EAMs) of 55 consecutive patients who underwent PVC ablation were analyzed. Spatial displacement between each point position during PVC and SR was obtained.
Results: A total of 6923 points from 71 EAMs were analyzed. Overall, the median distance between the point position during SR and PVC for all the points was 9.42 mm (interquartile range [IQR]: 6.19-12.85). The EAM points from the right ventricle showed more displacement than did those from the left ventricle: 10.35 mm (IQR: 7.16-13.95) vs 7.62 mm (IQR: 5.20-10.81); P <.001. The ventricular end-diastolic volume of the EAM during SR was greater than that during PVC (median difference: 9.75 [IQR: 0.37-19.67] mL; P = .002). A shorter coupling interval of the PVC was associated with greater spatial displacement (r = -.521; P <.001), higher end-diastolic volume reduction with respect to the SR beat (r = -.718; P = .001), and worse image integration (mean point-to-surface distance between EAM and 3-dimensional computed tomography-derived structure; r = -.642; P = .018).
Conclusions: There is a significant spatial displacement between the point position in SR and PVC, mainly in the right ventricle. This displacement increases with the shortening of the PVC coupling interval and can result in poorer image fusion and difficult catheter navigation/positioning for ablation.
(Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)