Atrial pacing to unmask the presence of epicardial muscular fibers connecting the right-sided pulmonary veins and right atrium - Epicardial muscular fibers connecting the right-sided PVs and RA

The prevalence of carina breakthrough during SR was higher in the EC-group than the gap-group (18 [95%] vs. 1 [4%] patients, p < .0001). The intervalSR-CS was larger in the EC-group versus gap-group (71 [interquartile range, 57-97] vs. 6 [2-9] ms, p < .0001). In all patients with an EC, RA ablation resulted in delay (32 [20-40] ms) (N = 15) or elimination of PV potentials (N = 5).