Heart Rate Variability Integrated into a Longitudinal Multimodal Model to Predict Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage

Figures

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  Figure 1. (a,b): A longitudinal plot of the best-performing HRV features. The feature value scores of patients with and without DCI are plotted in red and blue, respectively. The median scores are plotted as a line together with the interquartile range (colored area).

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  Figure 2. (A–D): Anchored score trajectories for the different feature sets. Panels (A–D) summarize the leave-one-out scores for the STATIC, LAB/BGA, HRV, and COMBINED models, respectively. The median scores are plotted as a line together with the interquartile range (colored area). In the background, thin, partially transparent lines indicate the scores of individual patients.

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  Figure 3. (A–D): Overall ROC AUCs for the different feature subsets: A comparison of the model output scores for the 48 h leading up to DCI. Boxplots of the model output scores for the different models. The scores were grouped according to whether a DCI occurred in the subsequent 48 h. Only scores up to the first DCI were considered, and patients were removed from the risk set after DCI occurrence. The effect size was measured and is shown as the ROC AUC.

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  Figure 4. (A–D): The time-dependent ROC AUC analysis across the different feature subsets and intervals. Panels (A–C) show the ROC AUC values computed for equal-event intervals: (i) day 2 until day 4.7, (ii) day 4.7 until day 6.1, (iii) day 6.1 until day 7.5, (iv) day 7.5 until day 9, and (v) day 9 until day 13.1 after symptom onset. The 95% confidence intervals are depicted by the vertical lines at the tips of the bars.

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  Figure 5. A timeline view of the ICU Cockpit® Dashboard with parameters reflecting HRV (HRV-TD-SDNN, the standard deviation of interbeat intervals; HRV-TD-RMSSD, the root mean square of the successive RR interval differences; HRV-FD-LF, the absolute power in the low-frequency band; and HRV-FD-LF/HF ratio, the ratio of power in the low-frequency band to the high-frequency band).