Research articles: ArrhythmiasIs the mid-diastolic isthmus always the best ablation target for re-entrant atrial tachycardias?De Simone, Antonioa; Anselmino, Matteob; Scaglione, Marcoc; Stabile, Giusepped; Solimene, Francescoe; De Bellis, Antonioa; Pepe, Marcoa; Panella, Alfonsoa; Ferraris, Federicob; Malacrida, Mauriziof; Maddaluno, Francescof; Gaita, Fiorenzob; García-Bolao, IgnaciogAuthor Information aClinica San Michele, Maddaloni bDepartment of Medical Sciences, ‘Città della Salute e della Scienza di Torino’ Hospital, University of Turin, Turin cCardinal Massaia Hospital, Asti dClinica Mediterranea, Naples eClinica Montevergine, Mercogliano fBoston Scientific Italia, Milan, Italy gClinica Universidad de Navarra, Pamplona, Spain Correspondence to Antonio De Simone, Laboratorio di Elettrofisiologia, Clinica San Michele, Via Montella, 16, Maddaloni 81024, CE, Italy Tel: +39 0823 208818; fax: +39 0823 208818; e-mail: [email protected] Received 15 July, 2019 Revised 12 November, 2019 Accepted 20 November, 2019 Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website (www.jcardiovascularmedicine.com). Journal of Cardiovascular Medicine: February 2020 - Volume 21 - Issue 2 - p 113-122 doi: 10.2459/JCM.0000000000000923 Buy SDC Metrics Abstract Aims We evaluated the ability of an ultrahigh mapping system to identify the most convenient Rhythmia ablation target (RAT) in intra-atrial re-entrant tachycardias (IART) in terms of the narrowest area to transect to interrupt the re-entry. Methods A total of 24 consecutive patients were enrolled with a total of 26 IARTs. The Rhythmia mapping system was used to identify the RAT in all IARTs. Results In 18 cases the RAT matched the mid-diastolic phase of the re-entry whereas in 8 cases the RAT differed. In these patients, the mid-diastolic tissue in the active circuit never represented the area with the slowest conduction velocity of the re-entry. The mean conduction velocity at the mid-diastolic site was significantly slower in the group of patients in which the RAT matched the mid-diastolic site (P = 0.0173) and that of the remaining circuit was significantly slower in the group in which the RAT did not match (P = 0.0068). The mean conduction velocity at the RAT was comparable between the two groups (P = 0.66). Conclusion Identifying the RAT in challenging IARTs by means of high-density representation of the wavefront propagation of the tachycardia seems feasible and effective. In one-third of cases this approach identifies an area that differs from the mid-diastolic corridor. © 2019 Italian Federation of Cardiology - I.F.C. All rights reserved.