Effects of Coupling Between Wave‐Induced Fluid Flow and Elastic Scattering on P ‐Wave Dispersion and Attenuation in Rocks With Aligned Fractures

2020 ◽  
Vol 125 (3) ◽  
Author(s):  
Junxin Guo ◽  
Boris Gurevich
Keyword(s):  
Fluid Flow ◽  
Elastic Scattering ◽  
Wave Dispersion ◽  
P Wave ◽  
P Wave Dispersion ◽  
Wave Induced ◽  
Dispersion And Attenuation

Estimation of P-wave dispersion and attenuation under pore-texture complexities in carbonates

2017 ◽  
Author(s):  
Lucas Cesar Oliveira ◽  
Roseane Missagia ◽  
Irineu Lima Neto ◽  
Marco de Ceia
Keyword(s):  
Wave Dispersion ◽  
P Wave ◽  
P Wave Dispersion ◽  
Pore Texture ◽  
Dispersion And Attenuation

scholarly journals P-wave dispersion and attenuation due to scattering by aligned fluid saturated fractures with finite thickness: theory and experiment

2018 ◽  
Vol 215 (3) ◽  
pp. 2114-2133 ◽  
Author(s):  
Junxin Guo ◽  
Da Shuai ◽  
Jianxin Wei ◽  
Pinbo Ding ◽  
Boris Gurevich
Keyword(s):  
Finite Thickness ◽  
Wave Dispersion ◽  
P Wave ◽  
P Wave Dispersion ◽  
Dispersion And Attenuation ◽  
Theory And Experiment

Rock physical properties controlling P-wave dispersion and attenuation in outcrop carbonate specimens

2017 ◽  
Author(s):  
Lucas C. Oliveira ◽  
Roseane M. Missagia ◽  
Irineu de A. Lima Neto ◽  
Marco A. R. de Ceia
Keyword(s):  
Physical Properties ◽  
Wave Dispersion ◽  
P Wave ◽  
P Wave Dispersion ◽  
Dispersion And Attenuation

P-wave dispersion and attenuation in fractured and porous reservoirs - poroelasticity approach

2009 ◽  
Vol 57 (2) ◽  
pp. 225-237 ◽  
Author(s):  
Boris Gurevich ◽  
Miroslav Brajanovski ◽  
Robert J. Galvin ◽  
Tobias M. Müller ◽  
Julianna Toms-Stewart
Keyword(s):  
Wave Dispersion ◽  
P Wave ◽  
P Wave Dispersion ◽  
Porous Reservoirs ◽  
Dispersion And Attenuation

TO STUDY THE EFFECT OF BMV ON P WAVE DISPERSION AND SHORT TERM PROGNOSTIC IMPACT OF P WAVE DISPERSION IN PREDICTION OF CLINICAL OUTCOME AFTER PERCUTANEOUS BALLOON MITRAL VALVULOPLASTY IN PATIENTS WITH MITRAL STENOSIS AND SINUS RHYTHM

2020 ◽  
Vol 4 (9) ◽  
Author(s):  
Ashish Kumar Agarwal ◽  
Daulat Singh Meena ◽  
Vijay Pathak ◽  
Anoop Jain ◽  
Rakesh Kumar Ola
Keyword(s):  
Clinical Outcome ◽  
Right Ventricular ◽  
Wave Dispersion ◽  
Tissue Doppler ◽  
P Wave ◽  
Short Term ◽  
P Wave Dispersion ◽  
Mitral Valvuloplasty ◽  
Percutaneous Balloon ◽  
Before And After

Background: The aim of the present study was to study the effect of percutaneous balloon mitral  valvuloplasty (PBMV) on P wave dispersion and to test the correlation between P-maximum and  P-dispersion to right ventricular function and pulmonary artery pressure before and after PMBV. Also to study the impact of P-maximum and P-wave dispersion on the short term clinical outcome after successful PBMV in patients with mitral stenosis (MS) and sinus rhythm. Methods: 75 patients undergoing PMBV were enrolled in this study. We evaluated P-maximum, P-minimum and P-wave dispersion before and one month and one year after PBMV . We studied the changes in pulmonary arterial pressure (PAP), left atrial (LA) dimension, mitral diastolic gradient, and mitral valve area, in addition to the changes in right ventricular function utilizing tissue Doppler assessment both before and after PMBV, in addition the role of the P-wave dispersion in prediction of late cardiac events. Results: There were significant decrease in mean diastolic gradient, PAP, and LA size and significant improvement in right ventricular tissue Doppler indices after PMBV. Accompany these hemodynamic changes after PMBV. P-maximum and P-wave dispersion were found to be decreased (P < 0.001). Conclusion: Successful PBMV was associated with a decrease in Pmax and PWD. These simple electrocardiographic indices may predict the success of the procedure immediately after PBMV.  The P-maximum and P-wave dispersion changes were correlated with significant impairment of right dysfunction and the degree of pulmonary artery pressure. Keywords: PBMV.PAP,LA

scholarly journals Evaluation of left atrial mechanics and p-wave dispersion as markers of left atrial cardiopathy in patients of embolic stroke of undetermined source (ESUS)

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Masood ◽  
M.M Azharuddin ◽  
S.M.K Ashraf ◽  
S Wahab
Keyword(s):  
Left Atrial ◽  
Wave Dispersion ◽  
Embolic Stroke ◽  
P Wave ◽  
Electromechanical Delay ◽  
P Wave Dispersion ◽  
Atrial Electromechanical Delay ◽  
Wave Duration ◽  
P Wave Duration ◽  
Increased Risk

Abstract Introduction Around 25% of all ischaemic strokes have no known cause despite standard investigations. Most of these cases are suspected to have an embolic source for ischaemia, leading to the moniker of Embolic Stroke of Undetermined Source (ESUS). Recent studies suggest that abnormalities of the left atrium, in the form of atrial cardiopathy, can lead to increased risk of stroke even in the absence of atrial fibrillation (AF), which may be either as precursors to AF or as independent risk factors for the development of left atrial thrombus and subsequent stroke. Purpose The aim of this study was to measure LA electromechanical dissociation, LA volumes and P-wave dispersion as markers of atrial cardiopathy in patients with ESUS to determine whether atrial cardiopathy may be in the causal pathway of ESUS. Methods 28 patients presenting with ischaemic stroke and fulfilling the criteria for ESUS were enrolled into this cross-sectional, observational study. All patients had 24-hour Holter monitoring done to rule out the presence of AF. The control group consisted of 28 age- and gender-matched apparently healthy individuals. On ECG, P-wave Dispersion (PWD) was calculated by subtracting minimum P-wave duration from maximum P-wave duration. On echocardiography, time intervals from the beginning of P-wave to beginning of A' wave from the lateral mitral annulus in tissue doppler imaging was measured as the atrial electromechanical delay. LA volumes were recorded using the Modified Biplane Simpson's method. Statistical analysis was performed using student's t-test, chi-square test, and Pearson's test. Results Baseline demographic and laboratory characteristics were similar between the two groups. Increased PWD (34.14±9.89 ms vs. 27.32±8.95 ms; p=0.01), atrial electromechanical delay (73.32±16.31 ms vs. 63.63±13.59 ms; p=0.02) and LA volumes were observed in patients with ESUS as compared to controls. A significant correlation was also found between these parameters (p&lt;0.01). Discussion According to the results of our study, PWD, atrial electromechanical delay and LA volumes may be novel predictors for ESUS. Atrial cardiopathy is a unique mechanism of thrombo-embolism in ESUS patients and our data establishes its association with ESUS. Further studies will be needed to shed more light on its role in the causality of stroke in the ESUS population. Measurement of electromechanical delay Funding Acknowledgement Type of funding source: None

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