Fig. 2From: Heart rate n-variability (HRnV) and its application to risk stratification of chest pain patients in the emergency departmentThe receiver operating characteristic (ROC) curves produced by heart rate n-variability (HRnV) model (performance was based on leave-one-out cross-validation), the History, ECG, Age, Risk factors and Troponin (HEART) score, the Thrombolysis in Myocardial Infarction (TIMI) score, and the Global Registry of Acute Coronary Events (GRACE) scoreBack to article page