Atrial Tachycardia Developing after Cavo-Tricuspid Isthmus Ablation: What is the Mechanism?

摘要

A 65-year-old man with a history of a myocardial infarction underwent a cavo-tricuspid isthmus (CTI) catheter ablation for CTI-dependent atrial flutter (AFL) (Fig. 1). He was referred for electrophysiologic testing (EPS) and catheter ablation of recurrent AFL, which developed 4 years after the CTI ablation. At the beginning of the EPS, AFL persisted. During the AFL, the 12-lead electrocardiogram exhibited a negative saw-tooth pattern in the inferior leads, positive P waves in lead VI and negative P waves in lead V6. The atrial activation sequence along the tricuspid annulus (TA) and activation time within the right atrium (RA) covering the entire tachycardia cycle length appeared identical to that during the counter-clockwise CTI-dependent AFL (Fig. 1)