Co-existence of atrial tachycardia and common atrial flutter: electrophysiological characteristics and radiofrequency catheter ablation.

Four patients, who had no prior atrial surgery, underwent radiofrequency ablation for clinically documented typical atrial flutter. In addition to typical atrial flutter re-entrant atrial tachycardia was initiated during electrophysiological study in these four patients. We used earliest atrial endocardial activation and concealed entrainment pace mapping with short stimulus-P interval (< 40 ms) to identify the exit site of slow conduction are of atrial flutter were located at the posteromedial right atrium between the coronary ostium and the tricuspid annulus and those of slow conduction area of atrial tachycardia were located at high lateral right atrium in all four patients. Radiofrequency energy applied to these exit sites successfully eliminated both atrial flutter and atrial tachycardia in these four patients. Typical atrial flutter and re-entrant atrial tachycardia with two distinct re-entrant circuits concomitantly occurring in patients without prior atrial surgery are rare. Radiofrequency ablation can abolish both atrial tachyarrhythmias in the same ablation session.