It has been over 15 years since Haissaguerre et al described successful ablation of paroxysmal atrial fibrillation (AF) by targeting pulmonary vein triggers. In the intervening years, AF ablation has exploded to become a dominant procedure in electrophysiology. Pulmonary vein isolation remains the cornerstone of AF ablation, yet despite countless studies and an expanding arsenal of tools and techniques, the outcomes of AF ablation have never improved dramatically beyond those initially achieved by Haissaguerre. In the face of an ever-growing population of patients with symptomatic AF, better ablation strategies have proven elusive. In light of the potential complications of AF ablation, there is a clear need to improve procedure effectiveness. However, we also need better ways to predict the effectiveness of the procedure to guide patient selection. Multiple studies have demonstrated that increased left atrial (LA) size correlates with worse AF ablation outcomes and that the results of ablation of paroxysmal AF are better than those of ablation of persistent AF. In this issue of HeartRhythm, Montserrat et al evaluate markers of LA function using 2-dimensional echocardiographic speckle tracking to assess LA strain and strain rate as well as compare these markers in patients with or without recurrent AF after first or second ablation. Recently, there has been a growing literature on the evaluation of atrial strain that has demonstrated its predictive value (1) to identify the risk of AF after cardiac surgery, (2) as an additive measure to the CHA2DS2-VASc score to predict thromboembolic risk in AF, and (3) to help predict the success rates after ablation. Other work has demonstrated that LA strain and strain rate correlate with LA structural remodeling seen on magnetic resonance imaging and has also shown them to correlate with fibrosis seen on histopathology. While some studies have demonstrated that LA strain correlates with LA size, others have suggested that LA strain may be an independent, or even more sensitive, predictor of the risk of progressive or recurrent AF. This growing literature clearly demonstrates that LA function might have an important impact on AF with respect to its risk of development and persistence, susceptibility to