LAUSR

Abstract Funding Acknowledgements Type of funding sources: None. Background Differently from catheter ablation (CA) of atrial fibrillation (AF), outcome data on CA of atrial re-entrant arrhythmias are scarce. Purpose We sought to evaluate predictors of recurrence at follow up in this setting. Methods We analysed consecutive patients undergoing mapping and CA left atrial tachyarrhythmia. Three-dimensional high-density activation and voltage maps were created for each investigated tachycardia by means of CARTO® system. Left atrial (LA) size was measured as the anteroposterior diameter on parasternal long axis view on transthoracic echocardiogram. Severe LA enlargement was defined for LA diameter >47 mm in women and >52 mm in men in accordance with guidelines. Results Eighty-eight patients were considered (67 ± 9 years old, 45% males) undergoing 94 CA procedures (1.1 ± 0.3 per patient). Most patient had past medical history of pulmonary vein isolation (57%). In the investigated population, 120 tachycardia morphologies were mapped and ablated. Acute procedural success was achieved in 97% of cases without any major complication. After a mean follow-up of 17 ± 11 months, the overall freedom from atrial arrhythmia was 58% and 65% after single and repeat procedures, respectively. Severe LA enlargement was the only variable associated with arrhythmia recurrence at follow-up and it was consistent after single and repeat procedures (Figure 1 A-B). Conclusion CA of complex left atrial tachyarrhythmia is safe and effective, and the mid- and long-term outcome is improved when LA is not severely enlarged. CA of should therefore be considered early in this patient population to achieve better clinical outcome. Arrhythmia recurrence at follow-up