New insights on the pathogenesis of atrial fibrillation in acute myocardial infarction: Data from the “ObseRvatoire des Infarctus de Côte d’Or” (RICO) survey

Background Atrial fibrillation (AF) is common after acute myocardial infarction (AMI), and associated with mortality. However, there is an unmet need in the understanding of the pathophysiology of AF in AMI. Heart rate variability (HRV) reflects the cardiovascular response to the autonomic nervous system (ANS). Objectives We investigated the relationship between ANS parameters and the occurrence of AF during AMI. Methods From the RICO survey, all consecutive patients hospitalized for AMI in our university hospital between June 2001 and November 2014 were prospectively analysed by Holter ECG  Results Among the 2035 included patients, 168 (8.2%) developed AF during AMI. Compared to the sinus-rhythm group, patients who developed AF were older (77 ± vs. 64 ± y, P P P P P P P Conclusion Our large prospective HRV analysis in AMI shows that low LF-HF ratio is a major predictor of AF. Our study strongly suggests that AF in AMI primarily occurs on previous underlying atrial electrical remodelling, rather than acute sympathovagal imbalance.