Incidence and anatomical locations of catheter instability during circumferential pulmonary vein isolation using contact force.

In addition to contact force (CF), catheter stability is considered to be an important factor in creating radiofrequency lesions.To evaluate the catheter stability during pulmonary vein isolation (PVI) using CF-sensing catheter.PVI was performed in 32 patients using a CF-sensing catheter. Operators were blinded to CF. The application was arbitrarily defined as a "visually unstable" point if the catheter moved ≥ 4 mm. Data were analyzed according to 6 predefined segments for the ipsilateral PVs. As a parameter of catheter stability, the standard deviation (SD) of CF and relative standard deviation (RSD = 100 × SD of CF /average CF) were introduced.A total of 932 RF applications with 426 visually unstable points (UP; 45.7%) and 506 stable points (SP; 54.3%) were analyzed. SD was significantly higher at UP (8.0 g versus 5.7 g, P < 0.001), and RSD was significantly higher at UP (43.7% versus 26.5%, P < 0.001). Higher RSD was associated with visual instability in all the segments of both PVs, however, higher SD of CF was not in all segments. At the antero-superior segment of the LPV, and the roof and posteroinferior segments of the RPV, the RSD values were over 50%, suggesting catheter instability.Catheter instability occurred in 45% of ablations during PVI and was predominantly located in the antero-superior segment of the LPV and postero-inferior segment of the RPV, which may result in incomplete lesion formation. RSD had significant correlation with visual catheter stability.