Inclusion criteria  Left atrial flutter1 inducible during electrophysiological evaluation. Clinical indication for ablation: a) symptoms (palpitations, dizziness, syncope, breathlessness, derangement, heart failure), tachymiopathy, b) poor heart rate control, or c) recurrence after electrical cardioversion or failure of one antiarrhythmic drug.  Informed consent.  Patients will be enrolled if LAFL is clinically suspected but finally randomized if this mechanism is established by electrophysiologic evaluation according to the criteria stated above.  Exclusion criteria  Previous ablation of LAFL. Previous linear ablation in the LA except for pulmonary vein isolation. Absolute contraindication for oral anticoagulation. Stroke or acute coronary syndrome less than 3 months before ablation. Complex congenital heart disease.