Radiofrequency ablation of atrial flutter.

Atrial flutter can be understood as atrial tachycardia due to a single intra-atrial macroreentrant circuit that is determined by fixed or functional boundaries. In various types of atrial flutter, radiofrequency ablation has become an established curative therapy. During the course of an ablation procedure, five steps can be distinguished: (1) determination of the reentrant circuit; (2) identification of the boundaries; (3) proof of the participation of an isthmus between the boundaries in the reentrant circuit; (4) connection of the barriers by a linear lesion; and (5) proof that the line of block is complete. After establishing these five steps, the acute and long-term results of atrial flutter ablation are comparable to those of other supraventricular tachycardias. In this review, we discuss these principles of atrial flutter ablation with an emphasis on typical atrial flutter.