Identification of Compensatory Arterial Dynamics in Swine Using a Non-Invasive Sensor for Local Vascular Resistance

2018 ◽  
Author(s):  
Lu Wang ◽  
Sardar Ansari ◽  
Kevin R. Ward ◽  
Kayvan Najarian ◽  
Kenn R. Oldham
Keyword(s):  
Cardiovascular System ◽  
Vascular Resistance ◽  
Systemic Circulation ◽  
Test Subject ◽  
Loop Model ◽  
Peripheral Vascular ◽  
Dynamics Model ◽  
Non Invasive ◽  
Peripheral Arterial ◽  
Pressure Changes

Autoregulatory dynamics of the cardiovascular system play an important role in maintaining oxygenated blood transportation throughout the human body. In this work, a feedback dynamics model of the cardiovascular system with respect to heartrate and peripheral vascular resistance effects on longer-term blood pressure changes in the systemic circulation is presented. The model is identified from data taken from a swine test subject, instrumented in part with a wearable, non-invasive sensor for estimating peripheral arterial radius. Comparative simulations for the open and close loop model highlight significantly changed hemodynamics after hemorrhage.

scholarly journals Vascular resistance arm of the baroreflex: methodology and comparison with the cardiac chronotropic arm

2020 ◽  
Vol 128 (5) ◽  
pp. 1310-1320
Author(s):  
J. Krohova ◽  
L. Faes ◽  
B. Czippelova ◽  
R. Pernice ◽  
Z. Turianikova ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Vascular Resistance ◽  
Vascular Tone ◽  
Heart Rate Response ◽  
Peripheral Vascular Resistance ◽  
Noninvasive Measurement ◽  
Peripheral Vascular ◽  
Pressure Changes

Baroreflex response consists of several arms, but the cardiac chronotropic arm (blood pressure changes evoking heart rate response) is usually analyzed. This study introduces a method to assess the vascular baroreflex arm with the continuous noninvasive measurement of peripheral vascular resistance as an output considering causality in the interaction between oscillations and slower dynamics of vascular tone changes. We conclude that although vascular baroreflex arm involvement becomes dominant during orthostasis, gain of this interaction is relatively stable.

scholarly journals CHANGES IN GAUSSIAN MODELING PARAMETERS OF PPG PULSE DURING HEALTHY PREGNANCY

2021 ◽  
pp. 2140001
Author(s):  
YU MENG ◽  
LIN YANG ◽  
SONG ZHANG ◽  
GUANGHUI WU ◽  
XIAOHONG LIU ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Cardiovascular System ◽  
Vascular Resistance ◽  
Gaussian Function ◽  
First Trimester ◽  
Peak Position ◽  
Peripheral Vascular Resistance ◽  
Flow State ◽  
Peripheral Vascular ◽  
Gaussian Modeling

We used Gaussian modeling to depict the changes in finger photoplethysmographic (PPG) pulse during pregnancy in healthy women. We enrolled 70 healthy pregnant women and recorded their PPG pulses in 11–13 gestational weeks, 20–22 gestational weeks, and 37–39 gestational weeks. Three independent positive Gaussian functions were utilized to decompose the pulses, and each Gaussian function extracted three key parameters: the peak amplitude ([Formula: see text]), the peak position ([Formula: see text]), and the half-width ([Formula: see text]). The method of ANOVA and post-hoc multiple comparisons of mathematical statistics were utilized to study the differences of these parameters between the three trimesters. We found that in the first trimester [Formula: see text] increased significantly ([Formula: see text]: [Formula: see text] versus [Formula: see text], [Formula: see text]). [Formula: see text] and [Formula: see text] increased in the first trimester ([Formula: see text]: [Formula: see text] versus [Formula: see text], [Formula: see text]; [Formula: see text]: [Formula: see text] versus [Formula: see text], [Formula: see text]), then decreased significantly ([Formula: see text]: [Formula: see text] versus [Formula: see text], [Formula: see text]: [Formula: see text] versus [Formula: see text], [Formula: see text]). [Formula: see text] is associated with cardiac output, and [Formula: see text] and [Formula: see text] are associated with peripheral vascular resistance. The results of this study were consistent with the conclusion that healthy pregnant women exhibited high flow state of the cardiovascular system and their peripheral vascular resistance decreased first and then gradually recovered during pregnancy. This study indicated that PPG pulse could also reflect the changes in the maternal cardiovascular system during pregnancy.

scholarly journals Method for recurrent gastrointestinal bleeding prognosis

2014 ◽  
Vol 95 (3) ◽  
pp. 446-449
Author(s):  
I S Simutis ◽  
G A Boyarinov ◽  
A S Mukhin ◽  
A V Deriugina ◽  
D B Prilukov
Keyword(s):  
High Risk ◽  
Gastrointestinal Bleeding ◽  
Vascular Resistance ◽  
Systemic Circulation ◽  
Peripheral Vascular Resistance ◽  
Whole Body ◽  
Recurrent Bleeding ◽  
Peripheral Vascular ◽  
Clinical Value ◽  
Total Peripheral Vascular Resistance

Aim. To assess the clinical value of continuous monitoring of rheographic parameters in patients with high risk of recurrent gastrointestinal bleeding for early pre-clinical diagnosis of recurrent bleeding. Methods. The study included 50 patients with upper gastrointestinal bleeding aged 50 to 70 years who were admitted having hemorrhagic shock III after endoscopic hemostasis. Continuous integral whole body rheography by «Diamant-M» computer complex was used for systemic circulation assessment. Results. Three types of hemodynamic reactions were revealed at integral whole body rheography: hypertonic (35 cases: increased integral tonicity coefficient up to 86 units and total peripheral vascular resistance over 3000 dyn/s·cm-5), hypotonic (35 cases: decreased integral tonicity coefficient down to 77 units and less, total peripheral vascular resistance less than 1500 dyn/s·cm-5, possible M-like waves of rheography curve) and intermediate (integral tonicity coefficient between 77 and 83 units, total peripheral vascular resistance between 1500 and 2000 dyn/s·cm-5). Integral tonicity coefficient between 80 and 113 units and total peripheral vascular resistance between 1500 and 3000±120 dyn/s·cm-5 were important indicators while monitoring for possible recurrent gastrointestinal bleeding. Conclusion. Blood loss compensation monitoring by continuous non-invasive rheography in patients at high risk for recurrent gastrointestinal bleeding allows not only diagnose recurrent gastrointestinal bleeding in a timely manner, but also to assess the effect of the treatment conducted.

Markers of arterial stiffness in peripheral arterial disease

VASA ◽  
2015 ◽  
Vol 44 (5) ◽  
pp. 341-348 ◽  
Author(s):  
Marc Husmann ◽  
Vincenzo Jacomella ◽  
Christoph Thalhammer ◽  
Beatrice R. Amann-Vesti
Keyword(s):  
Arterial Stiffness ◽  
Peripheral Arterial Disease ◽  
Pulse Wave ◽  
Augmentation Index ◽  
Arterial Disease ◽  
Care Physician ◽  
Additional Information ◽  
Non Invasive ◽  
Assessment Techniques ◽  
Peripheral Arterial

Abstract. Increased arterial stiffness results from reduced elasticity of the arterial wall and is an independent predictor for cardiovascular risk. The gold standard for assessment of arterial stiffness is the carotid-femoral pulse wave velocity. Other parameters such as central aortic pulse pressure and aortic augmentation index are indirect, surrogate markers of arterial stiffness, but provide additional information on the characteristics of wave reflection. Peripheral arterial disease (PAD) is characterised by its association with systolic hypertension, increased arterial stiffness, disturbed wave reflexion and prognosis depending on ankle-brachial pressure index. This review summarises the physiology of pulse wave propagation and reflection and its changes due to aging and atherosclerosis. We discuss different non-invasive assessment techniques and highlight the importance of the understanding of arterial pulse wave analysis for each vascular specialist and primary care physician alike in the context of PAD.

scholarly journals CT perfusion in peripheral arterial disease—hemodynamic differences before and after revascularisation

2021 ◽  
Author(s):  
Patrick Veit-Haibach ◽  
Martin W. Huellner ◽  
Martin Banyai ◽  
Sebastian Mafeld ◽  
Johannes Heverhagen ◽  
...  
Keyword(s):  
Peripheral Arterial Disease ◽  
Ct Perfusion ◽  
Arterial Disease ◽  
Lower Leg ◽  
Therapy Control ◽  
Non Invasive ◽  
Before And After ◽  
Invasive Method ◽  
The Mean ◽  
Peripheral Arterial

Abstract Objectives The purpose of this study was the assessment of volumetric CT perfusion (CTP) of the lower leg musculature in patients with symptomatic peripheral arterial disease (PAD) before and after interventional revascularisation. Methods Twenty-nine consecutive patients with symptomatic PAD of the lower extremities requiring interventional revascularisation were assessed prospectively. All patients underwent a CTP scan of the lower leg, and hemodynamic and angiographic assessment, before and after intervention. Ankle-brachial pressure index (ABI) was determined. CTP parameters were calculated with a perfusion software, acting on a no outflow assumption. A sequential two-compartment model was used. Differences in CTP parameters were assessed with non-parametric tests. Results The cohort consisted of 24 subjects with an occlusion, and five with a high-grade stenosis. The mean blood flow before/after (BFpre and BFpost, respectively) was 7.42 ± 2.66 and 10.95 ± 6.64 ml/100 ml*min−1. The mean blood volume before/after (BVpre and BVpost, respectively) was 0.71 ± 0.35 and 1.25 ± 1.07 ml/100 ml. BFpost and BVpost were significantly higher than BFpre and BVpre in the treated limb (p = 0.003 and 0.02, respectively), but not in the untreated limb (p = 0.641 and 0.719, respectively). Conclusions CTP seems feasible for assessing hemodynamic differences in calf muscles before and after revascularisation in patients with symptomatic PAD. We could show that CTP parameters BF and BV are significantly increased after revascularisation of the symptomatic limb. In the future, this quantitative method might serve as a non-invasive method for surveillance and therapy control of patients with peripheral arterial disease. Key Points • CTP imaging of the lower limb in patients with symptomatic PAD seems feasible for assessing hemodynamic differences before and after revascularisation in PAD patients. • This quantitative method might serve as a non-invasive method, for surveillance and therapy control of patients with PAD.

Characterization and clinical implications of peripheral arterial involvement in transthyretin cardiac amyloidosis cardiomyopathy

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K Stamatelopoulos ◽  
D Delialis ◽  
D Bampatsias ◽  
M.E Tselegkidi ◽  
I Petropoulos ◽  
...  
Keyword(s):  
Risk Factors ◽  
Clinical Significance ◽  
Vascular Involvement ◽  
Control Group ◽  
Peripheral Vascular ◽  
Cvd Risk Factors ◽  
Wave Reflections ◽  
Cvd Risk ◽  
Arterial Involvement ◽  
Peripheral Arterial

Abstract Background The sporadic form of transthyretin amyloidosis cardiomyopathy (ATTR-CM) is underdiagnosed but its prevalence is increasing due to the aging population. Given the poor prognosis of ATTR-CM understanding the underlying pathophysiologic mechanisms of the disease is imperative in order to improve strategies for early diagnosis and risk stratification and to develop new effective therapeutic options. ATTR-CM is associated with hypotension and there is preliminary experimental evidence of vascular involvement but its presence and clinical significance remains unknown. Purpose To characterize peripheral arterial involvement and explore its clinical role in ATTR-CM. Methods We consecutively recruited 28 previously untreated patients with newly diagnosed ATTR-CM and 34 elderly controls >70 years old, without ATTR-CM or heart failure. In both groups, flow-mediated dilatation (FMD) and intima-media thickness (IMT) in the carotid arteries were measured by high-resolution ultrasonography as markers of peripheral vascular reactivity and of subclinical atherosclerosis, respectively. Carotid-femoral pulse wave velocity (PWV) was measured as a marker of arterial stiffness. Aortic blood pressure (BP) and augmentation index (AI) using applanation tonometry were measured as markers of arterial wave reflections, peripheral arterial resistance and central hemodynamics. Echocardiography was performed in all ATTR patients. All cardiovascular (CV) measurements were performed before administration of any ATTR-specific therapy. Results ATTR patients were older and had lower prevalence of hypertension and male gender (p<0.05 for all) than the control group. Aortic and peripheral BP (p=0.016–0.088) and AI (p=0.003) were lower in ATTR patients. IMT in the common (cc) and internal carotid (ic) as well as in the carotid bulb (cb) were significantly higher in ATTR patients (p=0.001–0.042). After multivariable adjustment for traditional CV disease (CVD) risk factors, the ATTR group was independently associated with AI and IMT in cc, cb and ic (p<0.05 for all). In a subgroup of subjects with similar age between groups (n=13 and n=33 and 74.5±2.9 vs. 75.6±3.6 years, for ATTR vs. controls, respectively) differences in AI and cbIMT remained significant. Interestingly, AI was strongly and inversely associated with interventricular wall thickness (IVwt) in ATTR patients (spearman rho=−0.651, p=0.001). After adjustment for traditional CVD risk factors this association remained significant. Conclusion ATTR-CM is associated with lower aortic wave reflections, which correlate with more advanced structural cardiac disease, as assessed by IVwt. Further, ATTR-CM patients present accelerated subclinical carotid atherosclerosis as compared to elderly control subjects. These findings suggest that in ATTR-CM there is disease-specific peripheral vascular involvement in parallel to cardiac involvement. The clinical significance of these findings merits further investigation. Funding Acknowledgement Type of funding source: None

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