P1417
Short and long term efficiency of different therapeutic approaches to perimitral atrial flutter

Catheter ablation of perimitral flutter can be challenging, owing to difficult anatomy. The most commonly applied procedure is the creation of a mitral isthmus line (between the lower left pulmonary vein and the mitral anulus) or an anteroseptal line (between the upper right pulmonary vein and the anterior mitral anulus).

Our study aimed to compare the short and long term efficacy of two different ablation methods.

In our retrospective study 45 consecutive patients diagnosed with perimitral flutter were included between 2009 and 2018.

Radiofrequency ablation was performed in 48 cases in 31 patients (mitral isthmus line (n = 25, 52.1%); anteroseptal line (n = 23, 47.9%)). Arrhythmia-termination and sinus rhythm restoration could be achieved in 64.6% of the cases (mitral isthmus line: 16/25 (64.0%), anteroseptal line: 15/23 (65.2%). Comparing two different techniques, there was no significant difference (p = 0.85) in acute success rates. During 24.3 months of follow-up period, in 60.0% of the patients no recurrence occurred. The arrhythmia recurred in 6 cases (40.0%) after anteroseptal line ablation, and in 8 cases (53.3%) after mitral isthmus line ablation. No difference was found in the long term efficiency of two  different ablation techniques (p = 0.211).

In our retrospective study we found no significant difference in the short and long term efficiency of two different therapeutic approaches to perimitral atrial flutter.