Long RP tachycardia and ectopy identified on Holter monitoring (Patient 2). Top panel: episodes of narrow complex tachycardia (average RR interval 440 ms) were captured on Holter monitoring. Inverted P-waves are present suggesting an origin at the inferior aspect of the atria outside of the sinus node (blue arrows). The distance between the onset of the QRS (marked by n and a small black upward arrow) and the next P-wave is long and therefore is a ‘long RP’ tachycardia. Bottom panel: Episodes of atrial ectopy were also identified with a similar P-wave morphology (blue arrows). Prior to undergoing the second ablation procedure, this ectopy correlated with symptoms.