Konttila KK, Punkka O, Koivula K, et al. - Researchers intended to survey as well as compare the ≥10-year mortality of acute coronary syndrome (ACS) patients with sinus rhythm (SR) and atrial fibrillation (AF). Depending on rhythm in their 12-lead ECGs, patients were split into 2 categories: (1) SR (n = 788) at hospital admission and discharge (including sinus bradycardia, physiological sinus arrhythmia, and sinus tachycardia) and (2) AF/atrial flutter (n = 245) at both hospital admission and discharge, or SR and AF combination. Findings revealed that a poorer long-term result in ACS patients was independently predicted by AF/atrial flutter at admission and/or discharge, with 66% higher mortality within the ≥10-year follow-up span relative to patients with SR.