Sakamoto JT, et al. - Authors aimed to investigated how bradycardia affected Heart rate variability (HRV) analysis in patients who presented with chest pain to the Emergency Department (ED). Compared to chest pain patients without bradycardia, those with bradycardia indicated increased HRV. Findings seemed to have important implications on HRV modeling strategies for risk stratification of bradycardic and non-bradycardic chest pain patients.