Development of Lower Loop Reentrant Atrial Tachycardia in a Patient Late after Surgical Operation of Multiple Right-sided Accessory Pathways

A 50-year-old man developed a symptomatic tachyarrhythmia 22 years after surgical division of multiple right-sided accessory pathways. Electro-anatomical mapping during sinus rhythm revealed an electrically isolated ectopic focus on the right atrial free wall near the tricuspid annulus (TA). Activation map during tachycardia indicated the presence of lower loop reentry (LLR) with collision of the wavefronts in the high right atrium. The isthmus of slow conduction was located between the surgical incision near the posterior TA and the inferior vena cava. LLR was eliminated by radiofrequency linear ablation at the cavotricuspid isthmus.