Cinier G, et al. - Researchers performed a prospective, single center, observational study including patients presenting with ST-segment elevation myocardial infarction (STEMI) and referred to primary percutaneous coronary intervention (P-PCI) to determine if interatrial block (IAB) predicts atrial fibrillation (AF) at 12 months follow up in these patients. On admission and at 6th hour post P-PCI, surface electrocardiograms were recorded. To determine the occurrence of AF at a 12-months visit, patients were screened. Findings demonstrated that IAB is a common occurrence in patients with STEMI, and is linked to new onset of AF, along with the presence of diffuse coronary artery disease.