Ipek EG, et al. - Given that atrial flutter (AFL) remains a common form of arrhythmia recurrence after atrial fibrillation (AF) ablation, researchers examined AFL incidence and investigated the clinical factors associated with cavo-tricuspid isthmus dependent (typical) and atypical AFL, after AF ablation. They performed a retrospective cohort study of 1,029 patients who underwent initial radiofrequency AF ablation from May 2005 to December 2013 at a single academic center and included a total of 607 patients in the final cohort (age 59.2 ± 10.6 years, 76.0% men, 58.7% paroxysmal AF). AFL developed in 122 (20.1%) patients during a median follow-up of 845 days (interquartile range 389 to 1,597 days); of these, 17 had typical AFL, 98 had atypical AFL, and 7 patients had both circuits. The multivariable Cox regression analysis revealed a correlation of only right atrial volume index with incident typical AFL; whereas there was a correlation of persistent AF, linear lesions and left atrial volume index with incident atypical AFL. Findings thereby suggest a strong correlation of noninvasive measures of right and left atrial remodeling with incident AFL after AF ablation.