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

AIMS: 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.

METHODS AND RESULTS: 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.

CONCLUSION: 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.