"Trapped reentry" as source of acute focal atrial arrhythmias.

Abnormal electrical behavior under sinus rhythm has been found in the atria in the form of so-called complex fractionated atrial electrograms and atrial fibrillation nests. We show that this behavior could be a sign of an underlying "sleeping" arrhythmia, here referred to as trapped reentry, that can "wake up" and cause a tachyarrhythmia in the whole atria. With this new insight, we aim to trigger the active search for trapped reentry circuits in patients, to incite discussion among cardiac electrophysiologists about the clinical relevance of (awakening) dormant arrhythmias, and to fuel the search for improvements in arrhythmia treatment.