Atypical atrial flutter ablation: clinical practice on patient selection, mapping, ablation strategies, and procedural endpoints—results from a European Heart Rhythm Association survey

Atypical atrial flutter (AAFl) encompasses a diverse group of macro-reentrant arrhythmias with variable circuits, presenting diagnostic and therapeutic challenges. This European Heart Rhythm Association (EHRA) survey aimed to assess current practices across European centres regarding the management of AAFl.

A 26-item online questionnaire distributed by the EHRA Scientific Initiatives Committee yielded 214 responses from physicians in 36 countries. Catheter ablation was considered first-line therapy by 67.6% of respondents. In patients presenting in sinus rhythm with non-inducible clinical AAFl at the time of ablation, management strategies were heterogeneous, with combined pulmonary vein isolation and substrate ablation being the most common approach (46.8%). Activation mapping was the preferred method to define the circuit (63.7%), ahead of entrainment manoeuvers. Most respondents (87.1%) used ablation lines connecting scar or unexcitable tissue, whereas only 7.5% targeted the critical isthmus alone. The most frequent endpoints were validation of conduction block (73.1%), interruption of the clinical arrhythmia (71.0%), and non-inducibility of the clinical flutter (56.5%), while non-inducibility of any atrial flutter was rarely pursued. In patients without prior cardiac intervention, the left atrial anterior wall was perceived to be the most frequently involved structure (59.4%). Finally, in case of recurrence, 74.3% of respondents preferred redo ablation.

This EHRA survey reveals consensus on ablation endpoints but marked variability in ablation timing and strategies when AAFl is non-inducible at the time of ablation, underscoring the need for standardized protocols and further collaborative research to optimize outcomes.