Blanking period

The blanking period is a generally recognized three-month period during which arrhythmias after catheter ablation are not taken into account in the sense that they are excluded from the effectiveness analysis as supposedly unspecific events.

Arrhythmias can have various causes. The application of ablative energy to the atrial tissue has a pro-inflammatory effect, potentially causing acute inflammatory changes to lead to an immediate relapse.

In 35 to 65 percent of all cases, atrial arrhythmias occur within the first three months after ablation. If this is the case in the first month, it is a particular indication of possible late recurrences.

The early recurrences of arrhythmias such as atrial fibrillation, atrial flutter, left atrial (arising from the left atrium) tachycardia are abbreviated as ERAT in the medical literature. They are considered temporary and benign and occur in up to 40 percent of patients. However, half of this group with symptomatic ERAT after ablation will relapse.^[1]

Research has shown that ERAT primarily occurs within the first two weeks after ablation. Tissue edema after ablation disappears within a month. That is why a three-month blanking period has been criticized because it appears to be too long. A period of four weeks after surgical or transcatheteral ablations is considered to be more sensible. ^[2]

According to the latest studies, arrhythmia recurrences that occur in the first few weeks after catheter ablation for atrial fibrillation are not necessarily considered a failure of the procedure. It is assumed that such early recurrences, in contrast to late recurrences, are caused by temporary local inflammatory reactions in the atrium as a result of the procedure and heal on their own. However, a study by Korean cardiologists showed that in almost 70 percent of the cases examined, early recurrences were also followed by late recurrences.^[3]

Despite ablation, medication often cannot be avoided. Studies show that around 30 to 40 percent of participants continue to be treated with antiarrhythmic drugs despite atrial fibrillation ablation, which is due, among other things, to the early recurrences that occur during the blanking period, which are caused by local inflammatory reactions in the atrium. Such early recurrences can be prevented by using antiarrhythmic drugs. However, the benefit of such therapy is questionable, particularly if it continues beyond the blanking period.^[4]

• Gerhard Hindricks, Christopher Piorkowski, Hildegard Tanner, Richard Kobza, Jin-Hong Gerds-Li, Corrado Carbucicchio, Hans Kottkamp: Perception of atrial fibrillation before and after radiofrequency catheter ablation: relevance of the recurrence of asymptomatic arrhythmias. Circulation. July 19, 2005;112(3):307–13. doi:10.1161/CIRCULATIONAHA.104.518837.
• Sandeep Joshi, Andrew D. Choi, Ganesh Kamath, Farbod Raiszadeh, Daniel Marrero, Apurva Badheka, Suneet Mittal, Jonathan S. Steinberg: Prevalence, predictors and prognosis of atrial fibrillation soon after pulmonary vein isolation: results from 3 months of continuous automatic ECG loop recordings. J. Cardiovasc. Electrophysiol. 2009 Oct;20(10):1089–94. doi:10.1111/j.1540-8167.2009.01506.x.
• Sakis Themistoclakis, Robert A. Schweikert, Walid I. Saliba, Aldo Bonso, Antonio Rossillo, Giovanni Bader, Oussama Wazni, David J. Burkhardt, Antonio Raviele, Andrea Natale: Clinical predictors and association between early and late atrial tachyarrhythmias after pulmonary vein antral isolation. Cardiac rhythm. 2008 May;5(5):679–85. doi:10.1016/j.hrthm.2008.01.031.
• Nicolas Lellouche, Pierre Jaïs, Isbelle Nault, Matthew Wright, Michaela Bevilacqua, Sébastien Knecht, Seiichiro Matsuo, Kang-Teng Lim, Frederic Sacher, Antoine Deplagne, Pierre Bordachar, Mélèze Hocini, Michel Haïssaguerre: Early recurrences after ablation of atrial fibrillation: prognostic value and effect of early Reablation. J. Cardiovasc. Electrophysiol. 2008 Jun;19(6):599–605. doi:10.1111/j.1540-8167.2008.01188.x.

• Katheterablation bei Vorhofflimmern Health lexicon DocMedicus
• Vorhofflimmern: Frührezidive nach Ablation – kein Grund zur Sorge? Herzmedizin, March 18, 2021
• Nach Vorhofflimmern-Ablation: Welches Antiarrhythmikum ist besser geeignet? Springer Medizin, January 27, 2022