Fig 1.
Illustration of the RR intervals (RRIs) and the definitions of RRnI and RRnIm, where 1 ≤ n ≤ 3, 1 ≤ m ≤ 2.
Parameter m indicates the non-overlapping portion between two successive RRnIm sequences.
Fig 2.
Patient recruitment flowchart.
ECG: Electrocardiogram; ED: Emergency department; IHM: In-hospital mortality; SIRS: Systemic inflammatory response syndrome.
Table 1.
Baseline characteristics and clinical parameters.
Table 2.
Descriptive analyses of heart rate variability (HRV) and heart rate n-variability (HRnV) parameters.
Table 3.
Univariable analysis of HRV and HRnV parameters.
Table 4.
Multivariable analysis of HRV and HRnV parameters on 30-day in-hospital mortality.
Fig 3.
ROC curves for HRnV-based prediction models, alongside other disease severity scoring systems.
APACHE II: Acute Physiology and Chronic Health Evaluation II; AUC: Area under the receiver operating characteristic curve; HRnV: Heart rate n-variability; MEWS: Modified Early Warning Score; NEWS: National Early Warning Score; SOFA: Sequential Organ Failure Assessment; qSOFA(w): Worst quick SOFA score.