scholarly journals Evaluation of strain averaging area and strain estimation errors in a spheroidal left ventricular model using synthetic image data and speckle tracking

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jakub Żmigrodzki ◽  
Szymon Cygan ◽  
Krzysztof Kałużyński
Keyword(s):  
Speckle Tracking ◽  
Longitudinal Strain ◽  
Circumferential Strain ◽  
Radial Strain ◽  
Left Ventricular ◽  
Estimation Accuracy ◽  
Error Limit ◽  
Maximal Error ◽  
Strain Estimation ◽  
Partial View

Abstract Background In majority of studies on speckle tracking echocardiography (STE) the strain estimates are averaged over large areas of the left ventricle. This may impair the diagnostic capability of the STE in the case of e.g. local changes of the cardiac contractility. This work attempts to evaluate, how far one can reduce the averaging area, without sacrificing the estimation accuracy that could be important from the clinical point of view. Methods Synthetic radio frequency (RF) data of a spheroidal left ventricular (LV) model were generated using FIELD II package and meshes obtained from finite element method (FEM) simulation. The apical two chamber (A2C) view and the mid parasternal short axis view (pSAXM) were simulated. The sector encompassed the entire cross-section (full view) of the LV model or its part (partial view). The wall segments obtained according to the American Heart Association (AHA17) were divided into subsegments of area decreasing down to 3 mm2. Longitudinal, circumferential and radial strain estimates, obtained using a hierarchical block-matching method, were averaged over these subsegments. Estimation accuracy was assessed using several error measures, making most use of the prediction of the maximal relative error of the strain estimate obtained using the FEM derived reference. Three limits of this predicted maximal error were studied, namely 16.7%, 33% and 66%. The smallest averaging area resulting in the strain estimation error below one of these limits was considered the smallest allowable averaging area (SAAA) of the strain estimation. Results In all AHA17 segments, using the A2C projection, the SAAA ensuring maximal longitudinal strain estimates error below 33% was below 3 mm2, except for the segment no 17 where it was above 278 mm2. The SAAA ensuring maximal circumferential strain estimates error below 33% depended on the AHA17 segment position within the imaging sector and view type and ranged from below 3–287 mm2. The SAAA ensuring maximal radial strain estimates error below 33% obtained in the pSAXM projection was not less than 287 mm2. The SAAA values obtained using other maximal error limits differ from SAAA values observed for the 33% error limit only in limited number of cases. SAAA decreased when using maximal error limit equal to 66% in these cases. The use of the partial view (narrow sector) resulted in a decrease of the SAAA. Conclusions The SAAA varies strongly between strain components. In a vast part of the LV model wall in the A2C view the longitudinal strain could be estimated using SAAA below 3 mm2, which is smaller than the averaging area currently used in clinic, thus with a higher resolution. The SAAA of the circumferential strain estimation strongly depends on the position of the region of interest and the parameters of the acquisition. The SAAA of the radial strain estimation takes the highest values. The use of a narrow sector could increase diagnostic capabilities of 2D STE.

scholarly journals Myocardial Function in Offspring Aged 5 to 8 Years of Pregnancy Complicated by Severe Preeclampsia Measured by Two-Dimensional Speckle-Tracking Echocardiography

2022 ◽  
Vol 12 ◽  
Author(s):  
Huiyun Chen ◽  
Yu Gong ◽  
Fangcan Sun ◽  
Bing Han ◽  
Bingyuan Zhou ◽  
...  
Keyword(s):  
Right Ventricular ◽  
Speckle Tracking ◽  
Longitudinal Strain ◽  
Circumferential Strain ◽  
Speckle Tracking Echocardiography ◽  
Radial Strain ◽  
Left Ventricular ◽  
Two Dimensional ◽  
Preterm Children ◽  
2D Speckle Tracking

Objective: This study aimed to quantitatively assess myocardial strain in preterm children aged 5 to 8 years of pregnancy complicated by severe preeclampsia (PE) by two-dimensional (2D) speckle tracking echocardiography.Method: A cohort study of 23 preterm children delivered by severe PE pregnant women from 2010 to 2012 in the First Affiliated Hospital of Soochow University was carried out. 23 preterm children from uneventful pregnancies in the same period served as controls. Myocardial functions including left ventricular longitudinal strain, radial strain, circumferential strain, and right ventricular longitudinal strain were evaluated by conventional Doppler, tissue Doppler imaging, and 2D speckle-tracking echocardiography (2D STE). All examinations were performed by an experienced ultrasonographer using the VIVID E9 (GE Healthcare) machine, according to standard techniques.Results: Children aged 5–8 years delivered from severe PE presented less weight (24.41 vs. 20.89 kg, P < 0.05), shorter height (124.1 vs 115.6 cm, P < 0.05) and faster heart rates (84 vs. 93 bpm, P < 0.05) compared to offspring of normotensive women. There were no significant differences in global left ventricular longitudinal strain, radial strain, circumferential strain, and right ventricular longitudinal strain between the children in the experimental group and the control group (P > 0.05).Conclusion: Exposure to the intrauterine environment of severe PE during the fetal period did not have a significant impact on cardiac structure in premature children at 5–8 years old, but they had a higher resting heart rate which may be associated with cardiovascular disease in the long run.

scholarly journals Atrial and Ventricular Structural and Functional Alterations in Obese Children

Medicina ◽  
2021 ◽  
Vol 57 (6) ◽  
pp. 562
Author(s):  
Rima Šileikienė ◽  
Karolina Adamonytė ◽  
Aristida Ziutelienė ◽  
Eglė Ramanauskienė ◽  
Jolanta Justina Vaškelytė
Keyword(s):  
Speckle Tracking ◽  
Longitudinal Strain ◽  
Speckle Tracking Echocardiography ◽  
Myocardial Dysfunction ◽  
Global Longitudinal Strain ◽  
Radial Strain ◽  
Left Ventricular ◽  
Z Score ◽  
Obese Children ◽  
2D Speckle Tracking

Background and objectives: Childhood obesity has reached epidemic levels in the world. Obesity in children is defined as a body mass index (BMI) equal to or above the 95th percentile for age and sex. The aim of this study was to determine early changes in cardiac structure and function in obese children by comparing them with their nonobese peers, using echocardiography methods. Materials and methods: The study enrolled 35 obese and 37 age-matched nonobese children. Standardized 2-dimensional (2D), pulsed wave tissue Doppler, and 2D speckle tracking echocardiography were performed. The z-score BMI and lipid metabolism were assessed in all children. Results: Obese children (aged 13.51 ± 2.15 years; 20 boys; BMI z-score of 0.88 ± 0.63) were characterized by enlarged ventricular and atrial volumes, a thicker left ventricular posterior wall, and increased left ventricular mass. Decreased LV and RV systolic and diastolic function was found in obese children. Atrial peak negative (contraction) strain (−2.05% ± 2.17% vs. −4.87% ± 2.97%, p < 0.001), LV and RV global longitudinal strain (−13.3% ± 2.88% vs. −16.87% ± 3.39%; −12.51% ± 10.09% vs. −21.51% ± 7.42%, p < 0.001), and LV global circumferential strain (−17.0 ± 2.7% vs. −19.5 ± 2.9%, p < 0.001) were reduced in obese children. LV torsion (17.94° ± 2.07° vs. 12.45° ± 3.94°, p < 0.001) and normalized torsion (2.49 ± 0.4°/cm vs. 1.86 ± 0.61°/cm, p = 0.001) were greater in obese than nonobese children. A significant inverse correlation was found between LV and RV global longitudinal strain and BMI (r = −0.526, p < 0.01; r = −0.434, p < 0.01) and total cholesterol (r = −0.417, p < 0.01). Multivariate analysis revealed that the BMI z-score was independently related to LV and RV global longitudinal strain as well as LV circumferential and radial strain. Conclusion: 2D speckle tracking echocardiography is beneficial in the early detection of regional LV systolic and diastolic dysfunctions, with preserved ejection fraction as well as additional RV and atrial involvement, in obese children. Obesity may negatively influence atrial and ventricular function, as measured by 2D speckle tracking echocardiography. Obese children, though they are apparently healthy, may have subclinical myocardial dysfunction.

scholarly journals Left Ventricular Myocardial Deformations in Hemodialysis Children by Speckle Tracking Echocardiography

2020 ◽  
Vol 14 ◽  
pp. 117954682093001
Author(s):  
Manal F Elshamaa ◽  
Fatma A Mostafa ◽  
Inas AES Sad ◽  
Ahmed M Badr ◽  
Yomna AEM Abd Elrahim
Keyword(s):  
Speckle Tracking ◽  
Longitudinal Strain ◽  
Speckle Tracking Echocardiography ◽  
Systolic Dysfunction ◽  
Global Longitudinal Strain ◽  
Radial Strain ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Ventricular Ejection Fraction ◽  
Myocardial Mechanics

Background: Cardiac systolic dysfunction was potentially found in adult patients with end-stage renal disease (ESRD) who have preserved left ventricular ejection fraction (EF%). In children with ESRD, little data are available on early changes in myocardial function. This study aimed to detect the early changes in myocardial mechanics in pediatric patients with ESRD using speckle tracking echocardiography (STE). Methods: Thirty ESRD children receiving hemodialysis (HD) and30 age-matched controls were prospectively studied. Patients underwent echocardiographic studies before and after HD. Left ventricular longitudinal strain (LS), circumferential strain (CS), and radial strain (RS) myocardial deformation parameters (strain, strain rate) were evaluated by STE. Results: The LS was significantly reduced in pre-HD and post-HD patients compared with controls ( P = .000). Controls showed the highest global longitudinal strain. The RS measurements did not differ significantly among the studied groups except for the inferior segment that is significantly reduced after HD compared with controls ( P < .05). The CS was significantly reduced in pre-HD and post-HD patients compared with controls at the lateral and posterior segments ( P = .035 and P = .013, respectively). Conclusion: Speckle-tracking echocardiography might detect early changes in myocardial mechanics in children with ESRD with preserved EF%.

scholarly journals Left ventricular systolic function impairment in children after balloon valvuloplasty for congenital aortic stenosis assessed by 2D speckle tracking echocardiography

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0248862
Author(s):  
Krzysztof Godlewski ◽  
Paweł Dryżek ◽  
Elżbieta Sadurska ◽  
Bożena Werner
Keyword(s):  
Strain Rate ◽  
Speckle Tracking ◽  
Longitudinal Strain ◽  
Circumferential Strain ◽  
Systolic Function ◽  
Global Longitudinal Strain ◽  
Left Ventricular ◽  
Strain And Strain Rate ◽  
Eccentric Hypertrophy

Aims The aim of the study was to evaluate left ventricular (LV) remodeling and systolic function using two-dimensional speckle tracking echocardiographic (2D STE) imaging in children at a long-term (more than 36 months, 107.5±57.8 months) after balloon valvuloplasty for aortic stenosis (BAV). Methods and results 40 patients (mean age 9,68 years, 75% male) after BAV and 62 control subjects matched to the age and heart rate were prospectively evaluated. The 2D STE assessment of LV longitudinal and circumferential strain and strain rate was performed. Left ventricular eccentric hypertrophy (LVEH) was diagnosed in 75% of patients in the study group. Left ventricular ejection fraction (LVEF) was normal in all patients. In study group, global longitudinal strain (GLS), global longitudinal strain rate (GLSr) were significantly lower compared with the controls: GLS (-19.7±2.22% vs. -22.3±1.5%, P< 0.001), GLSr (-0.89±0.15/s vs. -1.04 ±0.12/s, P < 0.001). Regional (basal, middle and apical segments) strain and strain rate were also lower compared with control group. Global circumferential strain (GCS), global circumferential strain rate (GCSr) as well as regional (basal, middle and apical segments) strain and strain rate were normal. Multivariable logistic regression analysis included: instantaneous peak systolic Doppler gradient across aortic valve (PGmax), grade of aortic regurgitation (AR), left ventricular mass index (LVMI), left ventricular relative wall thickness (LVRWT), left ventricular end-diastolic diameter (LVEDd), peak systolic mitral annular velocity of the septal and lateral corner (S’spt, S’lat), LVEF before BAV and time after BAV and showed that the only predictor of reduced GLS was LV eccentric hypertrophy [odds ratio 6.9; (95% CI: 1.37–12.5), P = 0.045]. Conclusion Patients at long-term observation after BAV present the subclinical LV systolic impairment, which is associated with the presence of its remodeling. Longitudinal deformation is the most sensitive marker of LV systolic impairment in this group of patients.

Evaluation of Left Ventricular Dysfunction in Patients with Isolated Mitral Valve Stenosis Using Speckle Tracking Echocardiography

2021 ◽  
Vol 23 (Supplement_D) ◽  
Author(s):  
Mohamed ElGendi ◽  
Mohamed Ayman ◽  
Mohamed Sadaka ◽  
Gehan Magdi
Keyword(s):  
Speckle Tracking ◽  
Longitudinal Strain ◽  
Circumferential Strain ◽  
Speckle Tracking Echocardiography ◽  
Systolic Function ◽  
Systolic Dysfunction ◽  
Mean Value ◽  
Left Ventricular ◽  
2D Speckle Tracking ◽  
Lv Systolic Function

Abstract Aim The aim was to evaluate left ventricular (LV) systolic function in patients with isolated mitral stenosis (MS) using 2D speckle tracking echocardiography. Methods 24 patients (39.50 ± 5.55 years, 17 females) with isolated MS (MVA: 1.35 ± 0.16 cm2) with preserved LV systolic function and sinus rhythm were compared to 12 matched healthy control subjects (36.42 ± 5.99 years, 8 females). Conventional echocardiography was performed to both groups. Longitudinal strain and Circumferential strain echocardiography were obtained. Peak systolic strain was measured from the mean strain profile for a total of 17 segments of the LV for the longitudinal strain and 16 segments for the circumferential strain. Global longitudinal (G.L.) and circumferential strain (G.C.) were calculated separately as the average of the sum of the studied segments. Results The global longitudinal strain of the cases group ranged from -11 – -17% with a mean value of -14.67 ± -1.69% and that of the control group ranged from -15 – -20% with a mean value of -17.83 ± -1.53% with a statistically significant difference between the two groups. In our study, there was a negative but non-significant correlation between LV GLSS and LA diameter (r = -0.054, p = 0.802), Echo score (r = -0.018, p = 0.933) and PASP (r = 0.021, p = 0.922) in patients group. Also, the correlation was negative but non-significant between LV GCSS and LA diameter (r = -0.142, p = 0.507), Echo score (r = -0.200, p = 0.349) and PASP (r = -0.155, p = 0.471) in patients group. Conclusion • 2D speckle tracking echocardiography can detect subclinical LV systolic dysfunction which cannot be recognized by 2D conventional echocardiography. • Isolated rheumatic MS may be associated with subclinical LV systolic dysfunction.

Abstract 4246: Dobutamine-induced Reserve of the Two-dimensional Longitudinal Strain Rate Predicts Clinical and Neurohumoral Improvement After Levosimendan Treatment in Acutely Decompensated Chronic Heart Failure

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Vasiliki Bistola ◽  
Ioannis Paraskevaidis ◽  
Ignatios Ikonomidis ◽  
Ioannis Parissis ◽  
Gerasimos Filippatos ◽  
...  
Keyword(s):  
Strain Rate ◽  
Speckle Tracking ◽  
Longitudinal Strain ◽  
Nyha Class ◽  
Radial Strain ◽  
Left Ventricular ◽  
Contractile Reserve ◽  
Systolic Strain ◽  
Strain And Strain Rate ◽  
Longitudinal Strain Rate

Objective: Levosimendan improves symptoms and the hemodynamic profile in patients with acutely decompensated chronic heart failure (ADCHF). We aimed to investigate: the association of low dose dobutamine (DSE)-induced changes of two-dimensional strain parameters with the corresponding changes of left ventricular ejection fraction (LVEF) and left ventricular outflow tract velocity time integral (LVOT VTI) in patients with ADCHF, and whether left ventricular contractile reserve assessed by both conventional and speckle tracking echocardiography is associated with clinical and neurohumoral improvement after levosimendan treatment. Methods: Thirty one consecutive patients with ADCHF (mean age 65 ± 10 years, NYHA class 3.6 ± 0.3, LVEF 22 ± 6%) were studied by DSE (peak dose 20 μg/kg/min) prior to 24-hour infusion of levosimendan (0.01 μg/kg/min, without bolus). The LVEF, LVOT VTI, mean longitudinal, circumferential and radial strain and strain rate using speckle tracking imaging were measured. Results: Twenty-three patients (74%) had evidence of contractile reserve (increase of LVEF > 10% and LVOT VTI > 20% after peak dobutamine dose, CR+), and 8 (26%) showed no reserve (CR−). CR+ versus CR- patients demonstrated greater improvement of NYHA class (mean NYHA change: −1.0±0.5 vs −0.5±0.3 NYHA class, p=0.01), and reduction of b-type natriuretic peptide levels (− 34±30 vs + 4±31%, p <0.01) 48 hours after completion of treatment. By multivariate analysis, mean longitudinal systolic strain rate reserve (resting - peak longitudinal strain rate ΔLSR (%)) was the best predictor of improvement of NYHA class (p= 0.039) and BNP (p= 0.042) after levosimendan administration among the reserve of: LV FS, EF, LVOT VTI, longitudinal strain, circumferential and radial strain and strain rate. Conclusion: Dobutamine-induced reserve of 2-dimentional speckle tracking longitudinal systolic strain rate is associated with clinical and neurohumoral improvement after treatment with levosimendan in patients with ADCHF.

scholarly journals Layer-specific speckle tracking analysis of left ventricular systolic function and synchrony in maintenance hemodialysis patients

2019 ◽  
Author(s):  
Chang Liu ◽  
Zining Yan ◽  
Li Fan ◽  
Jun Huang ◽  
Dan Shen ◽  
...  
Keyword(s):  
Speckle Tracking ◽  
Longitudinal Strain ◽  
Circumferential Strain ◽  
Systolic Function ◽  
Systolic Dysfunction ◽  
Left Ventricular ◽  
Maintenance Hemodialysis ◽  
Middle Segment ◽  
Basal Segment ◽  
Myocardial Layer

Abstract Background: This study investigated the value of layer-specific strain analysis by twodimensional speckle tracking echocardiography (2D-STE) for evaluating left ventricular (LV) systolic function and synchrony in maintenance hemodialysis (MHD) patients. Methods: A total of 34 MHD patients and 35 healthy controls were enrolled in this study. Dynamic images were collected at the LV apical long-axis, the four- and twochamber, and the LV short-axis views at the basal, middle, apical segments. The layerspecific speckle tracking (LST) was used to analyze the longitudinal strain (LS) and circumferential strain (CS) of LV sub-endocardium, mid-myocardium, subepicardium, global longitudinal strain (GLS), global circumferential strain (GCS), the LV 17 segment time to peak LS (TTP), the peak strain dispersion (PSD). The differences in these parameters were compared between control and MHD, and the correlation between PSD and each LS parameter was examined. The receiver operator characteristic curve was used to evaluate the efficacy of three myocardial layer LS and CS in the assessment of LV systolic dysfunction in MHD. Results: MHD had comparable left ventricular ejection fraction (LVEF), but significantly smaller GLS, GCS, and three-layer LS and CS compared to the control. The three layer LS of the basal segment, middle segment, and apex segment was significantly reduced in the MHD compared to the normal, while the three myocardial layer CS of the basal segment, middle segment, and apex segment was significantly reduced in the MHD compared to the normal, except for the sub-endocardium of middle and apex segment. MHD had significantly higher TTP of LV 17 segments and PSD compared to controls, and had delayed peak time in most segments. In addition, PSD of MHD was positively correlated with subendocardial and mid-myocardial LS and GLS, but not with subepicardial LS. The area under the curves (AUCs) of sub-endocardial, mid-myocardial, and sub-epicardial LS in MHD were 0.894, 0.852, and 0.870, respectively; the AUCs of sub-epicardial, midmyocardial, and sub-endocardial CS were 0.852, 0.837, and 0.669, respectively. Conclusion: LST may detect the early changes of all three-layer LS and CS and PSD in MHD, and is a valuable tool to diagnose LV systolic dysfunction in MHD.

scholarly journals Спекл-трекинг эхокардиография в оценке систоло-диастолической функции левого желудочка при ишемической болезни сердца с учетом особенностей строения миокарда

2021 ◽  
pp. 19-38
Keyword(s):  
Coronary Heart Disease ◽  
Heart Disease ◽  
Left Ventricle ◽  
Speckle Tracking ◽  
Longitudinal Strain ◽  
Circumferential Strain ◽  
Speckle Tracking Echocardiography ◽  
Radial Strain

В обзоре представлены диагностические возможности спекл-трекинг эхокардиографии (speckle tracking echocardio graphy) для оценки систоло-диастолической функции левого желудочка при ишемической болезни сердца с учетом особенностей строения миокарда. Спиральное строение миокарда и взаимодействие разнонаправленных волокон левого желудочка усложняют задачу оценки регионарной и глобальной сократимости левого желудочка. Спекл-трекинг эхокардиография позволяет измерить деформацию миокарда в продольном, циркулярном и радиальном направлениях. Обсуждается клиническое использование метода при наиболее опасных формах ишемической болезни сердца: остром инфаркте миокарда и нестабильной стенокардии. Спекл-трекинг эхокардиография позволяет выявлять компенсаторное увеличение деформации интактного миокарда, а также ротации левого желудочка при нарушениях локальной сократимости. Измерение глобальных значений деформации, скручивания и раскручивания левого желудочка представляет прогностическую информацию у больных с острым инфарк том миокарда и нестабильной стенокардией. Несмотря на преимущества, существуют препятствия, затрудняющие использование данного метода в клинической практике. Основные из них - качество ультразвукового изображения и отсутствие общепринятых нормативных значений величин деформации. Ключевые слова: спекл-трекинг эхокардиография, продольная деформация, циркулярная деформация, радиальная деформация, левый желудочек, ишемическая болезнь сердца speckle tracking echocardiography, longitudinal strain, circumferential strain, radial strain, left ventricle, coronary heart disease

scholarly journals Layer-specific speckle tracking analysis of left ventricular systolic function and synchrony in maintenance hemodialysis patients

2019 ◽  
Author(s):  
Chang Liu ◽  
Zining Yan ◽  
Li Fan ◽  
Jun Huang ◽  
Dan Shen ◽  
...  
Keyword(s):  
Speckle Tracking ◽  
Longitudinal Strain ◽  
Circumferential Strain ◽  
Systolic Function ◽  
Systolic Dysfunction ◽  
Left Ventricular ◽  
Maintenance Hemodialysis ◽  
Middle Segment ◽  
Basal Segment ◽  
Myocardial Layer

Abstract Background: This study investigated the value of layer-specific strain analysis by twodimensional speckle tracking echocardiography (2D-STE) for evaluating left ventricular (LV) systolic function and synchrony in maintenance hemodialysis (MHD) patients. Methods: A total of 34 MHD patients and 35 healthy controls were enrolled in this study. Dynamic images were collected at the LV apical long-axis, the four- and twochamber, and the LV short-axis views at the basal, middle, apical segments. The layerspecific speckle tracking (LST) was used to analyze the longitudinal strain (LS) and circumferential strain (CS) of LV sub-endocardium, mid-myocardium, subepicardium, global longitudinal strain (GLS), global circumferential strain (GCS), the LV 17 segment time to peak LS (TTP), the peak strain dispersion (PSD). The differences in these parameters were compared between control and MHD, and the correlation between PSD and each LS parameter was examined. The receiver operator characteristic curve was used to evaluate the efficacy of three myocardial layer LS and CS in the assessment of LV systolic dysfunction in MHD. Results: MHD had comparable left ventricular ejection fraction (LVEF), but significantly smaller GLS, GCS, and three-layer LS and CS compared to the control. The three layer LS of the basal segment, middle segment, and apex segment was significantly reduced in the MHD compared to the normal, while the three myocardial layer CS of the basal segment, middle segment, and apex segment was significantly reduced in the MHD compared to the normal, except for the sub-endocardium of middle and apex segment. MHD had significantly higher TTP of LV 17 segments and PSD compared to controls, and had delayed peak time in most segments. In addition, PSD of MHD was positively correlated with subendocardial and mid-myocardial LS and GLS, but not with subepicardial LS. The area under the curves (AUCs) of sub-endocardial, midmyocardial, and sub-epicardial LS in MHD were 0.894, 0.852, and 0.870, respectively; the AUCs of sub-epicardial, midmyocardial, and sub-endocardial CS were 0.852, 0.837, and 0.669, respectively. Conclusion: LST may detect the early changes of all three-layer LS and CS and PSD in MHD, and is a valuable tool to diagnose LV systolic dysfunction in MHD.

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