Benefits of catheter ablation of typical cavotricuspid isthmus-dependent atrial flutter using half-normal saline

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Radiofrequency catheter ablation (RFA) of cavotricuspid isthmus–dependent atrial flutter (AFL) is a procedure with a high success rate and a low complication rate. The anatomical variation and irregularity of the isthmus, with the high local blood flow, can reduce the effectiveness of the lesion and consequently of the procedure. Recent data suggests that deeper ablation lesions can be created using open-irrigated catheters (CA) with half-normal saline (HNS). Purpose To assess the acute efficacy and safety of RFA of AFL with half-normal saline (HNS). Compare the results with CA irrigated with normal saline (NS). Methods Randomized, prospective, observational and single-center study. Consecutive patients with first AFL RFA between June 2019 and December 2020 were included. CA with HNS or NS were used, with a limit of 40 watts and 40° C. An RFA line was performed under fluoroscopic guidance or electroanatomic mapping. If necessary, the lesion was repeated until the arrhythmia was interrupted and the bidirectional block was achieved (success). Acute success, total radiofrequency time (RT), number of radiofrequency applications, and complications were analyzed. Results 38 patients with RFA of AFL were analyzed. 19 in the HNS and 19 in the NS group. There were no significant differences between the baseline characteristics of each group. (Table 1) The accute success rate was 100% with a median of 2 RFA applications in both groups. The mean RT in HNS was 7:10 vs 09:16 min in NS group; the t-test analysis did not show a significant difference (p = .2). A subanalysis was performed in those patients who required more than 2 lines of RFA; a mean of 4 in the HNS group vs 6 in the NS group (p = .4). In the HNS group, RT was significantly shorter; 8:17 vs 13:17 min in the NS group (p = .011). (Figure 1) There was a steam pop in the HNS group and no complications or steam pop in the NS group (p = .53). Conclusions RFA of AFL using HNS is an effective and safe procedure. In patients with unfavorable anatomy who required a greater number of applications, the radiofrequency time was significantly shorter using HNS. Baseline characteristicsHNS (19 p)NS(19 p)pAge56 ± 12.3 years61 ± 10.8 years.22Male16 p (84%)16 p (84%)1Heart Disease7 p (36.8%)5 p (26.3%).68Ejection Fraction57.1 ± 11%56 ± 14.3%.49Ejection Fraction < 50%2 p (10.5%)2 p (10.5%)1Electroanatomic mapping10 p (52.6%)8 p (42.1%).7Abstract Figure. Fugure 1