Objective: Septic shock (SS) patients often show elevated heart rate (HR) despite resuscitation, and this condition is considered an early manifestation of myocardial dysfunction due to an impairment of autonomic nervous system (ANS). We aimed at proposing a mathematical model to assess the autonomic control of ventricular contractility (VC) and HR to track changes in heart functionality during an experimental animal model of SS and resuscitation.
Methods: SS was induced in six adult swine by polymicrobial peritonitis. We analyzed the beat-to-beat variability of the maximum positive time derivative of left ventricular pressure (dP/dt max), heart period (HP), and aortic blood pressure (ABP). We identified the transfer functions relating fluctuations in ABP and HP to dP/dt max to characterize the static and dynamic properties of the arterial baroreflex and the force-frequency relation mechanisms, respectively. Standard indices of autonomic dysfunction have also been considered as HR variability (HRV) and baroreflex sensitivity (BRS).
Results: During baseline, the baroreflex is predominant in controlling VC with a gain value of -5.8 (-7.5,-3) s, compared to -1.2 (-1.9,-0.5) mmHg/s ms of the force-frequency autoregulation. During shock, both mechanisms increase their extent in VC control (higher gains and slightly faster dynamics for the baroreflex). After resuscitation, the physiological control of VC is not restored and all the animals still exhibit high HR and reduced HRV and BRS.
Conclusion: A condition of cardiovascular inefficiency is persistent after resuscitation and this could be due to autonomic dysfunction.
Significance: The ANS in SS is crucial to restore homeostasis. Our model could be used to evaluate the efficacy of treatments on VC and related control mechanisms.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1109/TBME.2019.2894333 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Butyrate increases cardiac output and causes vasorelaxation in a healthy porcine model.
Life Sci
January 2025
Department of Cardiology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 69, 8200 Aarhus N, Denmark; Department of Clinical Medicine, Aarhus University Hospital, Palle Juul-Jensens Boulevard 11, 8200 Aaarhus N, Denmark.
Background: Butyrate, a short-chain fatty acid, has shown potential to improve left ventricular (LV) function and induce vasorelaxation in rodents. Butyrate may either be produced by the microbiome in the colon, be ingested or administered intravenously. This study aimed to evaluate effects of butyrate on cardiac output (CO) and associated hemodynamic variables in a porcine model.
View Article and Find Full Text PDFCineECG Repolarization Gradients Predict Acute Hemodynamic Response in CRT Patients.
J Cardiovasc Electrophysiol
December 2024
Department of Cardiology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
Article Synopsis
- - The study investigates the effectiveness of a new ECG technique called CineECG, which visualizes heart electrical activity, in improving cardiac resynchronization therapy (CRT) for patients who don't respond well to standard treatments.
- - Researchers analyzed CineECG data from 15 patients with heart conditions under different pacing settings and found that specific movement directions in the heart's electrical signals correlate with better immediate heart performance (measured as dP/dt max).
- - The results indicate that the direction of the ST-T segment during repolarization can predict a significant improvement in heart function during CRT, suggesting that CineECG could help optimize treatment plans for patients.
Cardioprotective effects of S-equol, a soybean metabolite with estrogen activity, and role of the PI3K/Akt pathway in a male rat model of ischemic reperfusion.
Steroids
January 2025
Department of Anesthesiology, Faculty of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan.
Purpose: S-equol, an isoflavone metabolite with high estrogenic activity, exhibits organ-protective effects via the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway. While estrogen has cardioprotective effects against ischemia-reperfusion injury, whether S-equol shares this capability remains uncertain. This study aimed to assess the cardioprotective effects of S-equol on stunned myocardium using an isolated rat heart model and investigate the involvement of PI3K/Akt signaling pathway.
View Article and Find Full Text PDFdP/dt: An underestimated prognostic factor in large animal infarction model.
Animal Model Exp Med
November 2024
Department of Cardiology, Kaposi Moritz Teaching Hospital, Kaposvár, Hungary.
The present study aims to establish a reproducible large animal experimental unit using a minipig model to monitor cardiac function changes. A 90-min closed-chest balloon occlusion of the left anterior descending branch of the coronary artery was used to induce myocardial infarction in Pannon minipigs. To monitor the cardiac function, measurements were made by cardiac magnetic resonance imaging (cMRI), invasive pressure monitoring, and a Pulse index Continuous Cardiac Output (PiCCO) hemodynamic system at 0, 72, and 720 h during the follow-up period.
View Article and Find Full Text PDFCardioprotective effects of l-glutamine in an ischemic rat heart model.
Microvasc Res
November 2024
Department of Anesthesia, Royal Victoria Hospital, McGill University Health Centre Glen Site, Montreal, QC, Canada.
Introduction: l-glutamine has been shown to have cardioprotective effects in models of ischemia-reperfusion injury. Its potential cardioprotective effects when given before and during early reperfusion, however, have not been studied.
Methods: This study hypothesized that l-glutamine administered before and after myocardial ischemia provides better cardioprotection than when administered after ischemia only.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!