Pulsed-field ablation for refractory typical atrial flutter resistant to multiple radiofrequency ablations: A technical report.

This technical report presents a case with longstanding, recurrent typical atrial flutter who experienced multiple relapses despite four prior radiofrequency (RF) ablation procedures targeting the cavotricuspid isthmus (CTI). Initial RF attempts failed to achieve durable bidirectional CTI block, leading to persistent arrhythmia and significant symptom burden. Upon current admission, comprehensive electrophysiological mapping confirmed a scar-related, clockwise right atrial flutter with residual conduction across the CTI, notably on both the ventricular and inferior vena cava (IVC) sides. Given the fifth-do setting and previously scarred right atrial substrate, pulsed-field ablation (PFA) was selected as the ablation modality. Using a pentaspline PFA catheter, targeted ablation was successfully performed at the isthmus region. Residual fragmented atrial electrograms on both the ventricular and IVC sides of the isthmus were completely eliminated with paired PFA applications. High-density voltage remapping post-PFA confirmed durable electrical block across the CTI. No arrhythmia could be induced after the procedure, and the patient remained arrhythmia-free during 1-year follow-up without antiarrhythmic therapy. The procedure was complication-free, with no evidence of phrenic nerve injury, conduction system damage, or early / late coronary effects. This report suggests the integration of PFA into the therapeutic toolkit for recurrent CTI-dependent atrial flutter, particularly in patients who fail multiple conventional RF ablations. Prospective studies are warranted to validate these findings in larger populations and define long-term outcomes.