AF ablation and the blanking period

If you undergo an AF catheter ablation procedure for your AF, your doctor may have mentioned the term ‘blanking period’ to you. This is the post-ablation period (usually 3-months) during which recurrences of self-terminating episodes of AF can occur but may not be a reflection of overall procedural success. In other words, even if you have AF episodes in the blanking period after your ablation, you may still have long-term freedom from AF without needing further treatment.

Ablation involves applying energy to regions of heart muscle that are considered important for initiating AF. This is most often done using radio-frequency energy (heating up) or cryotherapy (freezing). This energy causes necrosis’ (damage) to the cells in a way that prevents them from conducting the AF and forms a block. This is an evolving process- in the first 24 hours there’s lots of swelling and bruising in the treated areas of the heart that may be causing the block. However, after this has resolved, the underlying scarring of the cells is what causes long-lasting block. So if ablation has caused swelling and bruising but not proper scarring, you might get an early elimination of AF but as time goes on and this resolves, it may come back.

Freedom from AF in the blanking period is strongly associated with longer term freedom. >90% correlation at 12 months reported in a recent meta-analysis. Recurrence during this period, especially day 60-90 may be associated with later recurrence. However, not always- 30-50% of patients with early recurrences during this blanking period did not experience late recurrence.

This is why:

1. you may be advised to continue your anti-arrhythmic medications for at least 3-months after your ablation.

2. (Part of the reason)Why you must continue anti-coagulation medication for at least 3 months after.

3. Your doctor may not consider any redo ablation procedure till at least an evaluation after this time point.

References you might be interested in:

Calkins H, Gache L, Frame D, Boo LM, Ghaly N, Schilling R, Deering T, Duytschaever M, Packer DL. Predictive value of atrial fibrillation during the postradiofrequency ablation blanking period. Heart Rhythm. 2021 Mar;18(3):366-373. doi: 10.1016/j.hrthm.2020.11.020. Epub 2020 Nov 24. PMID: 33242668.

Willems S, Khairy P, Andrade JG, Hoffmann BA, Levesque S, Verma A, Weerasooriya R, Novak P, Arentz T, Deisenhofer I, Rostock T, Steven D, Rivard L, Guerra PG, Dyrda K, Mondesert B, Dubuc M, Thibault B, Talajic M, Roy D, Nattel S, Macle L; ADVICE Trial Investigators*. Redefining the Blanking Period After Catheter Ablation for Paroxysmal Atrial Fibrillation: Insights From the ADVICE (Adenosine Following Pulmonary Vein Isolation to Target Dormant Conduction Elimination) Trial. Circ Arrhythm Electrophysiol. 2016 Aug;9(8):e003909. doi: 10.1161/CIRCEP.115.003909. PMID: 27516462.