Keywords
Macroreentrant atrial tachycardia
Septopulmonary bundle
Atrial flutter
Submitted : 2024-08-27
Accepted : 2024-09-11
Published : 2024-09-26
Abstract
Background: Epicardial roof-dependent atrial tachycardia is rare among macroreentrant tachycardias. The importance of epicardial structure or fiber involving septopulmonary bundle (SPB) has not been realized generally. Case presentation: A 74-year-old woman who underwent catheter ablation of atrial fibrillation previously accepted a second-time radiofrequency ablation due to atrial flutter. The mapping and entrainment results of the tachycardia tended to be an epicardial SPB-dependent macroreentrant atrial tachycardia and it was ablated to sinus rate at the first single targeting site, just located in the breakout site of SPB into the posterior wall (PW) of left atrial (LA). The twice-activation mapping of PW of LA also proved the presence of SPB. No recurrent arrhythmia was seen at follow-up at 3 months. Conclusion: In this case, an uncommon phenomenon was observed post-ablation for persistent atrial fibrillation, where the epicardial muscular structure of the LA-SPB was involved in atypical atrial flutter. This should be considered as a potential factor in such cases. Further similar cases may be required to improve diagnostic accuracy and to formulate effective ablation strategies for this type of tachycardia.
References
Markowitz SM, Thomas G, Liu CF, et al., 2019, Approach to Catheter Ablation of Left Atrial Flutters. J Cardiovasc Electrophysiol, 30(12): 3057–3067.
Ho SY, Sanchez-Quintana D, 2009, The Importance of Atrial Structure and Fibers. Clin Anat, 22(1): 52–63.
Pambrun T, Duchateau J, Delgove A, et al., 2021, Epicardial Course of the Septopulmonary Bundle: Anatomical Considerations and Clinical Implications for Roof Line Completion. Heart Rhythm, (18): 349–357.
Nayak HM, Aziz ZA, Kwasnik A, et al., 2020, Indirect and Direct Evidence for 3-D Activation During Left Atrial Flutter: Anatomy of Epicardial Bridging. JACC Clin Electrophysiol, 6(14): 1812–1823.
Hamoud NS, Abrich VA, Shen WK, et al., 2019, Achieving Durable Mitral Isthmus Block: Challenges, Pitfalls, and Methods of Assessment. J Cardiovasc Electrophysiol, 30(9): 1679–1687.
Briceno DF, Valderrabano M, 2014, Recurrent Perimitral Flutter Due to Vein of Marshall Epicardial Connections Bypassing the Mitral Isthmus: Response to Ethanol Infusion. Circ Arrhythm Electrophysiol, 7(5): 988–989.
Nakatani Y, Nakashima T, Duchateau J, et al., 2021, Characteristics of Macroreentrant Atrial Tachycardias Using an Anatomical Bypass: Pseudo-Focal Atrial Tachycardia Case Series. J Cardiovasc Electrophysiol, 32(9): 2451–2461.
De Ponti R, Verlato R, Bertaglia E, et al., 2007, Treatment of Macro-Re-Entrant Atrial Tachycardia Based on Electroanatomic Mapping: Identification and Ablation of the Mid-Diastolic Isthmus. Europace, 9(7): 449–457.