scholarly journals Observations on the Mean Pressure, and the Characters of the Pulse-wave in the Coronary Arteries of the Heart

1882 ◽  
Vol 3 (3-4) ◽  
pp. 165-174 ◽  
Author(s):  
H. Newell-Martin ◽  
W. T. Sedgwick
Keyword(s):  
Coronary Arteries ◽  
Pulse Wave ◽  
Mean Pressure ◽  
The Mean

scholarly journals Study on the Depth, Rate, Shape, and Strength of Pulse with Cardiovascular Simulator

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Ju-Yeon Lee ◽  
Min Jang ◽  
Sang-Hoon Shin
Keyword(s):  
Pulse Wave ◽  
Pulse Diagnosis ◽  
Pulse Wave Propagation ◽  
Reflected Wave ◽  
Slow Pulse ◽  
Rapid Pulse ◽  
Mean Pressure ◽  
The Mean ◽  
Cardiovascular Simulator ◽  
Crank Mechanism

Pulse diagnosis is important in oriental medicine. The purpose of this study is explaining the mechanisms of pulse with a cardiovascular simulator. The simulator is comprised of the pulse generating part, the vessel part, and the measurement part. The pulse generating part was composed of motor, slider-crank mechanism, and piston pump. The vessel part, which was composed with the aorta and a radial artery, was fabricated with silicon to implement pulse wave propagation. The pulse parameters, such as the depth, rate, shape, and strength, were simulated. With changing the mean pressure, the floating pulse and the sunken pulse were generated. The change of heart rate generated the slow pulse and the rapid pulse. The control of the superposition time of the reflected wave generated the string-like pulse and the slippery pulse. With changing the pulse pressure, the vacuous pulse and the replete pulse were generated. The generated pulses showed good agreements with the typical pulses.

scholarly journals Use and success evaluation of percutaneous aortic balloon valvuloplasty in different hemodynamic entities of severe aortic stenosis in the TAVR era

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K Piayda ◽  
A Wimmer ◽  
H Sievert ◽  
K Hellhammer ◽  
S Afzal ◽  
...  
Keyword(s):  
Heart Failure ◽  
Aortic Valve ◽  
Aortic Stenosis ◽  
Aortic Valve Replacement ◽  
Pressure Gradient ◽  
Severe Aortic Stenosis ◽  
Primary Treatment ◽  
Low Flow ◽  
Mean Pressure ◽  
The Mean

Abstract Background In the era of transcatheter aortic valve replacement (TAVR), there is renewed interest in percutaneous balloon aortic valvuloplasty (BAV), which may qualify as the primary treatment option of choice in special clinical situations. Success of BAV is commonly defined as a significant mean pressure gradient reduction after the procedure. Purpose To evaluate the correlation of the mean pressure gradient reduction and increase in the aortic valve area (AVA) in different flow and gradient patterns of severe aortic stenosis (AS). Methods Consecutive patients from 01/2010 to 03/2018 undergoing BAV were divided into normal-flow high-gradient (NFHG), low-flow low-gradient (LFLG) and paradoxical low-flow low-gradient (pLFLG) AS. Baseline characteristics, hemodynamic and clinical information were collected and compared. Additionally, the clinical pathway of patients (BAV as a stand-alone procedure or BAV as a bridge to aortic valve replacement) was followed-up. Results One-hundred-fifty-six patients were grouped into NFHG (n=68, 43.5%), LFLG (n=68, 43.5%) and pLFLG (n=20, 12.8%) AS. Underlying reasons for BAV and not TAVR/SAVR as the primary treatment option are displayed in Figure 1. Spearman correlation revealed that the mean pressure gradient reduction had a moderate correlation with the increase in the AVA in patients with NFHG AS (r: 0.529, p<0.001) but showed no association in patients with LFLG (r: 0.145, p=0.239) and pLFLG (r: 0.030, p=0.889) AS. Underlying reasons for patients to undergo BAV and not TAVR/SAVR varied between groups, however cardiogenic shock or refractory heart failure (overall 46.8%) were the most common ones. After the procedure, independent of the hemodynamic AS entity, patients showed a functional improvement, represented by substantially lower NYHA class levels (p<0.001), lower NT-pro BNP levels (p=0.003) and a numerical but non-significant improvement in other echocardiographic parameters like the left ventricular ejection fraction (p=0.163) and tricuspid annular plane systolic excursion (TAPSE, p=0.066). An unplanned cardiac re-admission due to heart failure was necessary in 23.7% patients. Less than half of the patients (44.2%) received BAV as a bridge to TAVR/SAVR (median time to bridge 64 days). Survival was significantly increased in patients having BAV as a staged procedure (log-rank p<0.001). Conclusion In daily clinical practice, the mean pressure gradient reduction might be an adequate surrogate of BAV success in patients with NFHG AS but is not suitable for patients with other hemodynamic entities of AS. In those patients, TTE should be directly performed in the catheter laboratory to correctly assess the increase of the AVA. BAV as a staged procedure in selected clinical scenarios increases survival and is a considerable option in all flow states of severe AS. (NCT04053192) Figure 1 Funding Acknowledgement Type of funding source: None

Coronary artery z score values in adolescent elite male soccer players

2020 ◽  
pp. 1-5
Author(s):  
Stephan Gerling ◽  
Tobias Pollinger ◽  
Markus Johann Dechant ◽  
Michael Melter ◽  
Werner Krutsch ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Coronary Arteries ◽  
High Intensity ◽  
Left Main Coronary Artery ◽  
Left Ventricular ◽  
Soccer Players ◽  
Z Score ◽  
Left Main ◽  
Luminal Diameter ◽  
The Mean

Abstract Background: With the increased training loads at very early ages in European elite youth soccer, there is an interest to analyse coronary artery remodelling due to high-intensity exercise. Design and methods: Prospective echocardiographic study in 259 adolescent elite male soccer players and 48 matched controls. Results: The mean age was 12.7 ± 0.63 years in soccer players and 12.6 ± 0.7 years in controls (p > 0.05). Soccer players had significant greater indexed left ventricular mass (93 ± 13 g/m2 versus 79 ± 12 g/m2, p = 0.001). Both coronary arteries origin could be identified in every participant. In soccer players, the mean diameter of the left main coronary artery was 3.67 mm (SD ± 0.59) and 2.61 mm (SD ± 0.48) for right main coronary artery. Controls showed smaller mean luminal diameter (left main coronary artery, p = 0.01; right main coronary artery, p = 0.025). In soccer players, a total of 91% (n = 196) and in controls a total of 94% (n = 45) showed left main coronary artery z scores within the normal range: −2.0 to 2.0. In right main coronary artery, a pattern of z score values distribution was comparable (soccer players 94%, n = 202 vs. controls 84%, n = 40). A subgroup of soccer players had supernormal z score values (>2.0 to 2.5) for left main coronary artery (9%, n = 19, p = 0.01) and right main coronary artery (6%, n = 10, p = 0.025), respectively. Conclusion: Elite soccer training in early adolescence may be a stimulus strong enough to develop increased coronary arteries diameters. In soccer players, a coronary artery z score >2.0–2.5 might reflect a physiologic response induced by multiannual high-intensity training.

Static mechanics of the velopharynx of patients with obstructive sleep apnea

1993 ◽  
Vol 75 (1) ◽  
pp. 148-154 ◽  
Author(s):  
S. Isono ◽  
D. L. Morrison ◽  
S. H. Launois ◽  
T. R. Feroah ◽  
W. A. Whitelaw ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Atmospheric Pressure ◽  
Exponential Relationship ◽  
Obstructive Sleep ◽  
Pressure Area ◽  
Mean Pressure ◽  
The Mean ◽  
Closing Pressure ◽  
Single Exponential

The static mechanics of the hypotonic pharynx were endoscopically evaluated in nine sleeping patients with obstructive sleep apnea, having a primary narrowing only at the velopharynx. The velopharynx closed completely at a mean pressure of 0.18 +/- 1.21 cmH2O, and the mean half-dilation pressure was 1.93 cmH2O above closing pressure. The dependence of area on pressure was distinctly curvilinear, being steep near closing pressure and asymptotically approaching maximum area (mean = 1.32 cm2). The data for each patient were satisfactorily fitted by an exponential function (mean R2 = 0.98), and a single exponential relationship usefully represented the dependence of relative area on pressure above closing pressure for the population (R2 = 0.85). During the test inspiration, flow limitation was consistently observed when mask pressure exceeded closing pressure by 0.5–3.0 cmH2O. In summary, the static mechanics of the hypotonic velopharynx of patients with obstructive sleep apnea can be described by an exponential pressure-area relationship, with a closing pressure near atmospheric pressure and a high compliance in the range of airway pressure 0–3 cmH2O above closing pressure.

An Investigation of the Forces on Three Dimensional Bluff Bodies in Rough Wall Turbulent Boundary Layers

1977 ◽  
Vol 99 (3) ◽  
pp. 503-509 ◽  
Author(s):  
B. E. Lee ◽  
B. F. Soliman
Keyword(s):  
Three Dimensional ◽  
The Body ◽  
Bluff Bodies ◽  
Drag Forces ◽  
Pressure Distributions ◽  
Mean Pressure ◽  
Flow Phenomena ◽  
The Mean ◽  
Building Ventilation ◽  
Group Density

A study has been made of the influence of grouping parameters on the mean pressure distributions experienced by three dimensional bluff bodies immersed in a turbulent boundary layer. The range of variable parameters has included group density, group pattern and incident flow type and direction for a simple cuboid element form. The three flow regimes associated with increasing group density are reflected in both the mean drag forces acting on the body and their associated pressure distributions. A comparison of both pressure distributions and velocity profile parameters with established work on two dimensional bodies shows close agreement in identifying these flow regime changes. It is considered that the application of these results may enhance our understanding of some common flow phenomena, including turbulent flow over rough surfaces, building ventilation studies and environmental wind around buildings.

scholarly journals Association of Aortic Pulse Wave Velocity with the Severity of Coronary Artery Disease in Patients with Non-ST-Segment Elevation Myocardial Infarction

2021 ◽  
Vol 36 (1) ◽  
pp. 38-46
Author(s):  
Pinaki Ranjan Das ◽  
Muhammed Aminur Razzaque ◽  
Rashid Ahmed ◽  
Shafiqul Islam ◽  
Rabindra Nath Barman ◽  
...  
Keyword(s):  
Pulse Wave ◽  
Aortic Pulse Wave Velocity ◽  
Coronary Angiogram ◽  
Invasive Strategy ◽  
Vessel Disease ◽  
Group I ◽  
The Mean ◽  
Group Ii ◽  
Artery Disease ◽  
Vessel Score

Background: Noninvasive assessment of arterial stiffness with aortic pulse wave velocity (PWV) may serve as a useful adjunct to the cardiovascular risk stratification and risk management. The aim of this study was to evaluate the association between aortic PWV and severity of coronary artery disease (CAD) in patients with non-STsegment elevation myocardial infarction (NSTEMI). Methods: This cross sectional analytical study was conducted over 100 NSTEMI patients who were purposively selected and agreed to do coronary angiogram during index hospital admission. PWV was assessed noninvasively using the SphygmoCor® system on the day before coronary angiogram (CAG). Study subjects were divided into two groups on the basis of PWV. In group I: PWV was ≤10 m/sec and in group II: PWV was > 10 m/sec. Fifty patients in each group. Angiographic severity of CAD was assessed by vessel score, Friesinger score and Leaman score. Results: Vessel score 2 and 3 were significantly (p<0.05) higher in group II and vessel score 0 and 1 were significantly (p<0.05) higher in group I. The mean PWV in the group with normal angiographic results was 8.21±1.8 m/sec, and in patients with single-vessel disease it was 9.88±2.02 m/sec. In those with double and triple vessel disease the mean PWV was found 11.95±2.61 m/sec and 14.37±2.96 m/sec respectively. There was a significant difference of the mean value of PWV among the vessel involvement group (p=0.001). Normal and low Friesinger score were significantly (p<0.05) higher in group I patients. Intermediate and high Friesinger score were significantly (p<0.05) higher in group II patients. Increased PWV was significantly associated with the presence and severity of CAD in NSTEMI. This association showed a positive linear relation between the values of PWV and vessel score (r=0.65, p=0.01), Friesinger score (r=0.61, p=0.01), and Leaman score (r=0.36, p=0.01). Conclusion: From this study it may be stated that arterial stiffness, as measured by the aortic PWV, is an independent predictor of the presence and extent of CAD. Measurements of aortic PWV in NSTEMI can detect high risk patients requiring an early invasive strategy over a delayed invasive strategy. Bangladesh Heart Journal 2021; 36(1) : 38-46

scholarly journals Normal values of coronary arteries branching height in women

2021 ◽  
Vol 27 (4) ◽  
pp. 41-46
Author(s):  
U.Ye. Pidvalna ◽  
D.M. Beshley ◽  
M.Z. Mirchuk ◽  
L.R. Mateshuk-Vatseba
Keyword(s):  
Body Mass Index ◽  
Coronary Artery ◽  
Body Mass ◽  
Coronary Arteries ◽  
Body Surface ◽  
Left Coronary Artery ◽  
Statistical Significance ◽  
Lower Edge ◽  
The Mean ◽  
The Right

Morphometric analysis of the structures of the aortic bulb and coronary arteries is necessary for the planning of cardiac surgery and endovascular interventions. The aim of the study was to determine the height of the coronary arteries branching in healthy women of Lviv city and Lviv region and to determine the relationship between the height of the location of the orifice of the coronary artery with anthropometric indicators. Fifteen computed tomography images with contrast of female thorax without heart and ascending aortic lesions (normal) were selected for the study. The height of the upper and lower edges of the coronary arteries was measured; height of Valsalva sinuses. The comparison of the mean values was performed according to the Student’s t-test. The correlation between the observed variables (age, height, body weight, body mass index, body surface area, height of the sinuses of Valsalva) was calculated using the Pearson linear correlation method (r). According to the study, the population group consisted of persons of the second period of adulthood (46.67 %) and the elderly (53.33 %). According to the body mass index, 80 % were overweight or obese I-II degree. The mean height of the coronary artery orifice in women without structural changes of the heart and ascending aorta was: 11.19±1.96 mm for the left and 11.68±1.80 mm for the right. The height of the orifice of the right and left coronary arteries were almost the same, without statistical significance (p=0.26). Analysis of the correlation between the values of the height of the orifice of the coronary artery did not show a probable dependence on height, weight, age, body mass index and body surface area. There is a direct relationship between the parameters of the height of the lower edge of the right coronary artery and the height of the upper edge of the right coronary artery (r=+0.75, p=0.001) and between the value of the lower edge of the left coronary artery and the upper edge of the left coronary artery (r=+0.63, p=0.01). Thus, the analysis of the correlation between the values of the height of the orifice of the coronary artery in women in norm and anthropometric indicators did not show a significant relationship. There was no statistical significance between the indicators of the height of the orifice of the right and left coronary arteries in women.

The Peroneal Groove Deepening Procedure: A Biomechanical Study of Pressure Reduction

2005 ◽  
Vol 26 (6) ◽  
pp. 442-448 ◽  
Author(s):  
Craig I. Title ◽  
Hung-Geun Jung ◽  
Brent G. Parks ◽  
Lew C. Schon
Keyword(s):  
Biomechanical Study ◽  
Posterior Tibial Tendon ◽  
Peroneal Tendon ◽  
Foot And Ankle ◽  
Calcaneofibular Ligament ◽  
Significant Difference ◽  
Mean Pressure ◽  
Fresh Frozen ◽  
The Mean ◽  
Pressure Changes

Background: The goal of this study was to identify pressure changes throughout the peroneal groove after a groove deepening procedure. We hypothesized that pressures would decrease. Methods: Twelve fresh-frozen foot and ankle specimens were used. A thin pressure strip containing four sensor pads was secured within the peroneal groove with pads 1 through 4 positioned at the calcaneofibular ligament (CFL) and at the distal, middle, and proximal groove, respectively. The midstance phase of gait was simulated with loads applied to the plantar foot and posterior tibial tendon and to the peroneus longus and brevis tendons. Pressures were recorded with the ankle in neutral, plantarflexion, dorsiflexion, inversion, and eversion. Groove deepening was done by osteotomizing the posterior fibular wall. Pressure readings were then recorded. Average pressures for each of the four sensor pads after the procedure were compared to those obtained before the procedure. Results: The mean pressure overlying the CFL increased at all five ankle positions; however, these changes were not significant. Significant decreases in pressure were noted within the distal and middle groove at all ankle positions after the peroneal groove deepening procedure. Pressure within the proximal groove increased at all but one position, with a significant difference noted in neutral and plantarflexion. Conclusion: Pressures within the middle and distal peroneal groove significantly decreased after a groove deepening procedure. Combining this technique with peroneal tendon debridement may be advantageous for treatment of partial peroneal tendon tears or recalcitrant peroneal tendinitis.

On Turbulent Flow Between Parallel Plates

1953 ◽  
Vol 20 (1) ◽  
pp. 109-114
Author(s):  
S. I. Pai
Keyword(s):  
Turbulent Flow ◽  
Velocity Distribution ◽  
Poiseuille Flow ◽  
The Other ◽  
Turbulent Velocity ◽  
Parallel Plates ◽  
Mean Velocity ◽  
Reynolds Equations ◽  
Mean Pressure ◽  
The Mean

Abstract The Reynolds equations of motion of turbulent flow of incompressible fluid have been studied for turbulent flow between parallel plates. The number of these equations is finally reduced to two. One of these consists of mean velocity and correlation between transverse and longitudinal turbulent-velocity fluctuations u 1 ′ u 2 ′ ¯ only. The other consists of the mean pressure and transverse turbulent-velocity intensity. Some conclusions about the mean pressure distribution and turbulent fluctuations are drawn. These equations are applied to two special cases: One is Poiseuille flow in which both plates are at rest and the other is Couette flow in which one plate is at rest and the other is moving with constant velocity. The mean velocity distribution and the correlation u 1 ′ u 2 ′ ¯ can be expressed in a form of polynomial of the co-ordinate in the direction perpendicular to the plates, with the ratio of shearing stress on the plate to that of the corresponding laminar flow of the same maximum velocity as a parameter. These expressions hold true all the way across the plates, i.e., both the turbulent region and viscous layer including the laminar sublayer. These expressions for Poiseuille flow have been checked with experimental data of Laufer fairly well. It also shows that the logarithmic mean velocity distribution is not a rigorous solution of Reynolds equations.

Sign in / Sign up

Export Citation Format

Share Document