Cavotricuspid isthmus is constantly a zone of slow conduction: Data from ultra‐high‐resolution mapping

• Published in: Pacing and clinical electrophysiology 2020-02, Vol.43 (2), p.189-193
• Main Authors: Bun, Sok‐Sithikun, Lațcu, Decebal Gabriel, Wedn, Ahmed Mostfa, Squara, Fabien, Scarlatti, Didier, Theodore, Guillaume, Al Amoura, Alaa, Benaïch, Fatima Azzahrae, Hasni, Karim, Saoudi, Nadir, Ferrari, Emile
• Format: Article
• Language: English
• Subjects: Aged; Atrial Flutter - physiopathology; Atrial Flutter - surgery; Body Surface Potential Mapping; Cardiac Pacing, Artificial; Catheter Ablation; cavotricuspid isthmus; Conduction; Electrocardiography; Female; Heart Conduction System - physiopathology; Humans; Male; Mapping; Monaco; slow conduction; Tricuspid Valve - physiopathology; typical atrial flutter; ultra‐high‐resolution mapping
• ISSN: 0147-8389; 1540-8159
• DOI: 10.1111/pace.13862

Background Whether cavotricuspid isthmus (CTI) is a region of conduction slowing during typical flutter has been discussed with conflicting results in the literature. We aimed to evaluate conduction velocity (CV) along the different portions of the typical flutter circuit with a recently proposed method by means of ultra‐high‐resolution (UHR) mapping. Methods Consecutive patients referred for typical atrial flutter (AFL) ablation underwent UHR mapping (Rhythmia, Boston Scientific). CVs were measured in the CTI as well as laterally and septally, respectively, from its lateral and septal borders. Results A total of 33 patients (mean age: 65 ± 13 years; right atrial volume: 134 ± 57 mL) were mapped either during ongoing counterclockwise (n = 25), or clockwise (n = 3) AFL (mean cycle length: 264 ± 38 ms), or during coronary sinus pacing at 400 ms (n = 1), 500 ms (n = 1), or 600 ms (n = 3). A total of 13 671 ± 7264 electrograms were acquired in 14 ± 9 min. CTI CV was significantly lower (0.56  ± 0.18 m/s) in comparison with the lateral CV (1.31 ± 0.29 m/s; P