Heart-rate-derived variability measures and in-hospital mortality in critically ill patients with heart failure and atrial fibrillation: insights from the MIMIC-IV database

The prognostic value of heart-rate-derived variability measures in critically ill patients with coexisting heart failure (HF) and atrial fibrillation (AF) remains unclear. In this high-risk population, conventional electrocardiogram-derived heart rate variability metrics are not directly applicable. We therefore investigated the associations of heart-rate-derived variability measures and early heart rate change patterns with in-hospital mortality in critically ill patients with HF and AF. We con