scholarly journals The potential of duplex scanning in the diagnosis of pathological tortuosity of the vertebral artery

2021 ◽  
pp. 84-95
Author(s):  
H. A. Yunusov ◽  
D. D. Sultanov ◽  
A. D. Gaibov ◽  
B. U. Abduvakhido ◽  
O. Nematzoda ◽  
...  
Keyword(s):  
Blood Flow ◽  
Vertebral Artery ◽  
Vessel Diameter ◽  
Arterial Blood Flow ◽  
Duplex Scanning ◽  
Accurate Information ◽  
Vertebral Arteries ◽  
Vertebrobasilar System ◽  
Arterial Blood ◽  
Before And After

Aim. To assess the capabilities of duplex scanning and study the features of hemodynamics in the vertebral arteries before and after surgical treatment.Material and methods. The results of anatomical and circulatory characteristics of an extracranial segment of the vertebral arteries in 52 patients with various forms of pathological tortuosity were analyzed. Kinking was present in 38 patients, coiling in 8 patients, and Powers anomaly in 6 patients. There were 18 men and 34 women. The mean age of the patients was 45.6±8.7 years.Results and discussion. In all types of PT of VA with ostium stenosis, the diameter of the artery was decreased, and based on tortuosity it contributed both to the reduction and deterioration of arterial blood flow to the vertebrobasilar basin. The decrease or increase in the linear velocity of blood flow, as well as other blood flow parameters, depended on both the type of pathological tortuosity of the PA and on the vessel diameter and the value of angulation. Hypoplasia of the opposite vertebral artery also occurred in 28 patients, which resulted in impaired blood supply to the brain.Vascular examination after reconstructive surgeries resulted in normalization of the parameters of arterial circulation and cerebral perfusion. Primary vascular patency was 96.2%, restenosis was not revealed in any observation.Conclusion. Duplex scanning is a highly informative technique for both diagnosing pathological deformities of the vertebral arteries and assessing the restoration of the hemodynamics of the vertebrobasilar system after reconstructive surgery. This method provides the most accurate information on the anatomical form and localization of pathological deformities of the vertebral artery. It also allows quantitative assessment of cerebral blood flow.

A novel laboratory approach for the demonstration of hemodynamic principles: the arterial blood flow reflection

2013 ◽  
Vol 37 (4) ◽  
pp. 321-326 ◽  
Author(s):  
Marina Djelić ◽  
Sanja Mazić ◽  
Dejan Žikić
Keyword(s):  
Blood Flow ◽  
Age Groups ◽  
Exercise Program ◽  
Arterial Blood Flow ◽  
New Approach ◽  
Arterial Blood ◽  
Before And After ◽  
Physical Laws ◽  
Laboratory Training ◽  
Flow Waveforms

In the frame of a laboratory training course for medicine students, a new approach for laboratory exercises has been applied to teach the phenomena of circulation. The exercise program included measurements of radial artery blood flow waveform for different age groups using a noninvasive optical sensor. Arterial wave reflection was identified by measurements of blood flow waveforms before and after arterial branching. Students were able to distinguish between different waveforms of blood flow within different age groups. Furthermore, students were given the opportunity to explore the effect of aging on the elasticity of blood vessels. This exercise is an introduction to the fundamental physical laws of hemodynamics that can facilitate the learning and understanding of cardiovascular physiology to students of medicine.

Numerical Analysis of Blood Flow in the Vertebral Artery

1982 ◽  
Vol 104 (2) ◽  
pp. 143-147 ◽  
Author(s):  
Takayoshi Fukushima ◽  
Takehiko Azuma ◽  
Teruo Matsuzawa
Keyword(s):  
Blood Flow ◽  
Numerical Analysis ◽  
Vertebral Artery ◽  
Arterial Blood Flow ◽  
Vascular Lesions ◽  
Shear Stresses ◽  
Hemodynamic Forces ◽  
Atherosclerotic Lesions ◽  
Arterial Blood ◽  
Structure Of Flow

Abnormal hemodynamic forces associated with distortions of blood vessel lumen have been thought to play an important role in the pathogenesis of focal vascular lesions. In the vertebral artery, segments located between osseous rings are ectatic compared with those surrounded by the rings. Based on the assumption that arterial blood flow was quasi-steady, this work was undertaken to investigate the structure of flow through arterial models with one or two sinusoidal stenoses. Numerical analysis was performed by an integral-momentum method. The validity of the method was examined by comparison of experimental data so far reported with theoretical results. Velocity and wall shear stress distributions were explored in a model with two stenoses simulating a part of the vertebral artery. The ectatic segments of the vertebral artery have been known as predilection sites for atherosclerotic lesions. The present study suggested that the ectatic wall was under unstable shear stresses, the direction of which was dependent upon the magnitude of the Reynolds number.

scholarly journals Symptomatic arterial hypertension in extrasystolic arrythmia

2021 ◽  
Vol 20 (Supplement_1) ◽  
Author(s):  
O Germanova ◽  
AV Germanov ◽  
G Galati ◽  
YV Shchukin
Keyword(s):  
Blood Flow ◽  
Mitral Valve ◽  
Arterial Hypertension ◽  
Arterial Blood Flow ◽  
Arterial Walls ◽  
Arterial Blood ◽  
Before And After ◽  
Wall Deformation ◽  
Valve Opening ◽  
The Moment

Abstract Funding Acknowledgements Type of funding sources: None. Within the main causes of the secondary arterial hypertensions the main roles play renal, endocrine and hemodynamic. In the list of reasons of the secondary hemodynamic arterial hypertension there’re no extrasystoles. Purpose. To determine the relationship between different types of  extrasystoles and the the secondary hemodynamic arterial hypertension. Materials and methods.  We observed 132 patients with supraventricular and ventricular extrasystoles. Extrasystoles were divided into groups due to the moment of their appearance in cardiocycle: 1. Extrasystoles before the mitral valve opening. 2,3.  Exstrasystoles in phase of fast ventricules filling before and after the peak of transmitral blood flow. 4. Extrasystoles in slow ventricules filling phase.  5. Other extrasystoles (allorrhythmias and group extrasystoles).  The reason for that dividing was the different contribution of each type into the hemodynamics and heart output. We analyzed the regular, extraordinary and first post-extrasystolic contractions. Intra-arterial blood flow was estimated by ultrasound-doppler. The moment of extrasystoles appearance was determined by echocardiography, electrocardiography and 24-hours ECG monitoring. The kinetics of vessel wall was calculated by sphygmograms and included speed, acceleration, power and work parameters. The BP measuring was made by Korotkov method that the moment of measuring was in the first post-extrasystolic wave on sphygmogram. We duplicated it after the normalization and calibration of carotid arteries sphygmograms. Results. The main importance to the hemodynamic changes has the moment of extrasystole appearance in cardio cycle and the ability of the first post-extrasystolic contraction to reestablish an adequate resulting blood flow. It is characterized by: stroke volume rising from 5 to 40%; systolic BP increase up to 30% (with formation of the secondary hemodynamic AH) compared with the systolic BP with normal heart rate; rising of arterial walls kinetic parameters (speed, acceleration, power, work); blood flow velocity rising; grown arterial wall deformation.  The maximum of these parameters was in first post-extrasystolic contraction with extrasystoles before the mitral valve opening and extrasystoles before the transmitral peak blood outflow. The special hemodynamic situation appears when there’re allorrhythmias when, for example, in case of constant bigeminia, BP is increased in 50% of time, and in case of trigimenia – in 1/3 of time. Conclusion. We believe it’s necessary to include extrasystoles into the list of the reasons of  the  secondary hemodynamic arterial hypertension. The main features of this type of AH are: unstable BP rising, prevalence growth of systolic BP, direct relationship with extrasystoles’ appearance moment. The risen blood flow of first post-extrasystolic contraction can be the reason of additional arterial walls deformation and complications that may cause the any AH.

Martial arts technique for control of severe external bleeding

2019 ◽  
Vol 36 (3) ◽  
pp. 154-158 ◽  
Author(s):  
John P Slevin ◽  
Cierra Harrison ◽  
Eric Da Silva ◽  
Nathan J White
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Arterial Blood Flow ◽  
Research Subjects ◽  
Vessel Occlusion ◽  
Arterial Blood ◽  
Decrease Blood Flow ◽  
Before And After ◽  
Haemorrhage Control

ObjectivesHaemorrhage control is a critical component of preventing traumatic death. Other than the battlefield, haemostatic devices, such as tourniquets or bandages, may not be available, allowing for significant avoidable blood loss. We hypothesised that compression of vascular pressure points using a position adapted from the martial art of Brazilian Jiu-Jitsu could be adapted to decrease blood flow velocity in major extremity arteries.MethodsKnee mount compression was applied to the shoulder, groin and abdomen of healthy adult volunteer research subjects from Seattle, Washington, USA, from March through May 2018. Mean arterial blood flow velocity (MAV) was measured using ultrasound in the brachial and femoral arteries before and after compression. A MAV decrease greater than 20% with compression was deemed clinically relevant.ResultsFor 11 subjects, median (IQR) MAV combining all anatomical locations tested was 29.2 (34.1, 24.1) cm/s at baseline and decreased to 3.3 (0, 19.1) cm/s during compression (Wilcoxon p<0.001). MAV was significantly decreased during compression for each individual anatomical position tested (Wilcoxon p≤0.004). Per cent (95% CI) MAV reduction was significantly greater than 20% for shoulder compression at 97.5%(94% to 100%) and groin compression at 78%(56% to 100%), but was not statistically greater for abdominal compression at 35%(12% to 57%). Complete vessel occlusion was most common with compression at the shoulder (73%), followed by groin (55%) and abdomen (9%) (χ² LR, p=0.018).ConclusionThe Brazilian Jiu-Jitsu knee mount position can significantly decrease blood flow in major arteries of the extremities. This technique may be useful for bleeding control after injury.

Modeling Elastic Walls in Lattice Boltzmann Simulations of Arterial Blood Flow

2013 ◽  
Vol 23 (2) ◽  
Author(s):  
Xenia Descovich ◽  
Giuseppe Pontrelli ◽  
Sauro Succi ◽  
Simone Melchionna ◽  
Manfred Bammer
Keyword(s):  
Blood Flow ◽  
Lattice Boltzmann ◽  
Arterial Blood Flow ◽  
Arterial Blood ◽  
Lattice Boltzmann Simulations ◽  
Elastic Walls

scholarly journals Sustained Inflation Reduces Pulmonary Blood Flow during Resuscitation with an Intact Cord

Children ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 353
Author(s):  
Jayasree Nair ◽  
Lauren Davidson ◽  
Sylvia Gugino ◽  
Carmon Koenigsknecht ◽  
Justin Helman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Perinatal Asphyxia ◽  
Arterial Blood Flow ◽  
Positive Pressure ◽  
Optimal Timing ◽  
Delayed Cord Clamping ◽  
Arterial Blood ◽  
Cord Clamping ◽  
Sustained Inflation ◽  
Near Term

The optimal timing of cord clamping in asphyxia is not known. Our aims were to determine the effect of ventilation (sustained inflation–SI vs. positive pressure ventilation–V) with early (ECC) or delayed cord clamping (DCC) in asphyxiated near-term lambs. We hypothesized that SI with DCC improves gas exchange and hemodynamics in near-term lambs with asphyxial bradycardia. A total of 28 lambs were asphyxiated to a mean blood pressure of 22 mmHg. Lambs were randomized based on the timing of cord clamping (ECC—immediate, DCC—60 s) and mode of initial ventilation into five groups: ECC + V, ECC + SI, DCC, DCC + V and DCC + SI. The magnitude of placental transfusion was assessed using biotinylated RBC. Though an asphyxial bradycardia model, 2–3 lambs in each group were arrested. There was no difference in primary outcomes, the time to reach baseline carotid blood flow (CBF), HR ≥ 100 bpm or MBP ≥ 40 mmHg. SI reduced pulmonary (PBF) and umbilical venous (UV) blood flow without affecting CBF or umbilical arterial blood flow. A significant reduction in PBF with SI persisted for a few minutes after birth. In our model of perinatal asphyxia, an initial SI breath increased airway pressure, and reduced PBF and UV return with an intact cord. Further clinical studies evaluating the timing of cord clamping and ventilation strategy in asphyxiated infants are warranted.

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