Local impedance measurements during contact force‐guided cavotricuspid isthmus ablation for predicting an effective radiofrequency ablation

• Published in: Journal of arrhythmia Vol. 38; no. 2; pp. 245 - 252
• Main Authors: Sasaki, Takehito, Nakamura, Kohki, Minami, Kentaro, Take, Yutaka, Nakatani, Yosuke, Miki, Yuko, Goto, Koji, Kaseno, Kenichi, Yamashita, Eiji, Koyama, Keiko, Naito, Shigeto
• Format: Journal Article
• Language: English
• Published: Japan John Wiley & Sons, Inc 01.04.2022; John Wiley and Sons Inc; Wiley
• Subjects: Ablation; Ablation (Surgery); atrial flutter; Bepridil; Catheters; cavotricuspid isthmus; contact force; Dexmedetomidine; Diabetes; Electrodes; Heart failure; Hypertension; local impedance; Medical equipment and supplies industry; Medical test kit industry; Original; radiofrequency catheter ablation; Transient ischemic attack; United States; radiofrequency catheter ablation; cavotricuspid isthmus; contact force; atrial flutter; local impedance
• ISSN: 1880-4276; 1883-2148
• DOI: 10.1002/joa3.12680

Background An ablation catheter capable of contact force (CF) and local impedance (LI) monitoring (IntellaNav StablePoint, Boston Scientific) has been recently launched. We evaluated the relationship between the CF and LI values during radiofrequency catheter ablation (RFCA) along the cavotricuspid isthmus (CTI). Methods Fifty consecutive subjects who underwent a CTI‐RFCA using IntellaNav StablePoint catheters were retrospectively studied. The initial CF and LI at the start of the RF applications and mean CF and minimum LI during the RF applications were measured. The absolute and percentage LI drops were calculated as the difference between the initial and minimum LIs and 100 × absolute LI drop/initial LI, respectively. Results We analyzed 602 first‐pass RF applications. A weak correlation was observed between the initial CF and LI (r = 0.13) and between the mean CF and LI drops (r = 0.22). The initial LI and absolute and percentage LI drops were greater at effective ablation sites than ineffective ablation sites (median, 151 vs. 138 Ω, 22 vs. 14 Ω, and 14.4% vs. 9.9%; p < .001), but the initial and mean CF did not differ. At optimal cutoffs of 21 Ω and 10.8% for the absolute and percentage LI drops according to the receiver‐operating characteristic analysis, the sensitivity, and specificity for predicting an effective ablation were 57.4% and 88.9% and 80.0%, and 61.1%, respectively. Conclusions The effective sites during the CF‐guided CTI‐RFCA had greater initial LI and LI drops than the ineffective sites. Absolute and percentage LI drops of 21 Ω and 10.8% may be appropriate targets for an effective ablation. During radiofrequency catheter ablation (RFCA) along the cavotricuspid isthmus (CTI) using an ablation catheter capable of simultaneous contact force (CF) and local impedance (LI) monitoring, the effective ablation sites exhibited higher initial local impedance (LI) values and greater LI drops than the ineffective ablation sites. The receiver operating characteristic analysis suggested that an absolute LI drop of 21 Ω and percentage LI drop of 10.8% may be suitable targets for an effective ablation during a CTI‐RFCA.