Focal atrial tachycardia from the aortic root – long-term outcomes compared to right and left atrial focal atrial tachycardia

Background
Focal atrial tachycardia (FAT) represent a common arrhythmia in the field of electrophysiology. In a small subset of patients these tachycardias originate from the aortic root. Ablation of these is more challenging, as biatrial mapping often suggests an origin either from the his-bundle or from the aortic root.
This study aimed to further investigate procedural characteristics and long-term outcome of FAT originating from the aortic root compared to right and left atrial FATs.

Methods
All consecutive patients presenting at the German Heart Center Munich from 04/2011 to 02/2024 were included in this study (n = 367 patients). Three groups of patients were defined: right atrial FAT (n = 215; 58,6%), left atrial FAT (n = 111; 30,3%) and aortic FAT (n = 41; 11,1%). Follow-up data was collected through visits at the outpatient clinic and partially by telephonic interviews. For safety analysis, all complications requiring intervention or causing sequels occurring during or up to 30 days after catheter ablation were collected. For efficacy, FAT-free survival was analysed without a blanking period.

Results
Clinical baseline characteristics and procedural data are listed in table 1. The majority of aortic FAT originated from the non-coronary cusp (73,8%), 7.1% from the right coronary cusp, the remaining FAT originated from the transition in between the cusps. Mean patients’ age was 55.4 ± 18.6 years (min-max: 9 – 87 years). Mean procedure duration was 134.3 ± 58.5 minutes with 15.1 ± 15.4 minutes of radiofrequency duration. 17% of all patients were ablated with a high power short duration setting. The average FAT cycle length was 422.7 ± 84.9 ms. One patient required permanent pacemaker implantation due to a persistent AV-block after ablation close to the his-bundle. In 4,18% groin complications occurred, including minor complications as hematoma > 5cm. No stroke or pericardial tamponade was observed. On average, patients received 1,19 ± 0.50 ablation in a follow-up period of 1651.3 ± 1249.8 days (median 1348 days). 93,7% of patients are considered recurrence-free with no significant differences in the subgroups of right-, left-atrial or aortic FATs (Figure 2).

Conclusion
Ablating focal atrial tachycardia (FAT) can be challenging and time-consuming due to the variety of origins. Despite these difficulties, 93,7% of patient did not suffer recurrences after 1.19 ± 0.50 ablations. FATs originating from the aortic root, mainly the non-coronary cusp, can be ablated as safely and effective as FATs originating from the left or right atrium.