Rockstroh C, Kirchner J, Krämer T, Hensel B (2011)
Publication Language: English
Publication Type: Conference contribution, Abstract of lecture
Publication year: 2011
Conference Proceedings Title: Biomedizinische Technik. Biomedical engineering, vol. 56, iss. s1
URI: https://www.degruyter.com/view/j/bmte.2011.56.issue-s1/bmt.2011.851/bmt.2011.851.xml
DOI: 10.1515/BMT.2011.517
Introduction
Circadian variation reflects the overall activity of a patient and thus promises to particularly indicate changes in cardiac function in patients with congestive heart failure (CHF). A model that allows reconstructing parameters of the day-night rhythm with a minimal set of presuppositions is provided by the non-stationary Langevin equation. The clinical applicability of these parameters was evaluated.
Methods
We analyzed 24-h RR-interval time series, which are publicly available at PhysioNet.org. The study populations included patients with normal sinus rhythm as well as with mild to medium CHF. From the Langevin model, parameters were derived that correspond to heart rates typical for day and night phases, respectively, to the difference between these values and to sleeping duration. Additionally, standard parameters of heart rate variability in time domain were computed, which serve as gold standard for cardiologic time series analysis. In order to estimate the impact of measurement artifacts on the method, analysis was performed both on raw and filtered signals.
Results
The Langevin parameters discriminate between patients with normal sinus rhythm and those suffering from mild CHF as well as the standard HRV parameters. When applied to patient groups with mild and medium CHF, respectively, the new approach performs even better than the gold standard. Hence, both the onset and worsening of heart failure are indicated by the new parameters. In contrast to the standard HRV parameters, these results remain unaltered if the raw instead of the filtered signal is used. These results indicate that the parameters from circadian variation are robust against measurement artifacts. Sensitivity to clinical cofounders is unlikely, due to tests with medium CHF patients from different databases showing no significant differences.
Conclusion
The Langevin approach to circadian variation provides robust markers for changes in cardiac condition, which are hence suitable for clinical use.
APA:
Rockstroh, C., Kirchner, J., Krämer, T., & Hensel, B. (2011). Assessing the Severity of Congestive Heart Failure by New Parameters of Circadian variation. Paper presentation at 45. DGMBT Jahrestagung (BMT 2011), Freiburg, DE.
MLA:
Rockstroh, Christian, et al. "Assessing the Severity of Congestive Heart Failure by New Parameters of Circadian variation." Presented at 45. DGMBT Jahrestagung (BMT 2011), Freiburg 2011.
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