Introduction
Typical atrial flutter (AFL) is a common atrial arrhythmia that can
result in significant morbidity and mortality when left
untreated1, 2. Catheter ablation is a highly
effective, first-line treatment for typical AFL that results in a low
recurrence rate and reduction of stroke risk3, 4.
Whereas ablation of the flutter circuit is indicated in patients with
documented AFL, it may also be a reasonable consideration in those
without a documented AFL history, but high risk of unrecognized AFL or
development of AFL in future5. This may allow for
attenuation of stroke risk in a group that may eventually present with
thromboembolic complications as the first indication of AFL. A simple
diagnostic maneuver to determine the existence of a potential AFL
circuit, and therefore a risk of occult or future AFL, would be very
useful. This could support the decision on whether to empirically ablate
a flutter circuit at time of ablation for other rhythms, such as atrial
fibrillation. We investigated right atrial collision time (RACT) during
coronary sinus pacing as a surrogate marker of a potential right atrial
flutter circuit, and thereby a candidate marker of occult or future AFL
which may inform anticoagulation and ablation decisions.