The definition of normal values of left ventricular global longitudinal strain (GLS), global circumferential strain, and global radial strain is of critical importance to the clinical application of ...this modality. The investigators performed a meta-analysis of normal ranges and sought to identify factors that contribute to reported variations.
MEDLINE, Embase, and the Cochrane Library database were searched through August 2011 using the key terms "strain," "speckle tracking," "left ventricle," and "echocardiography" and related phrases. Studies were included if the articles reported left ventricular strain using two-dimensional speckle-tracking echocardiography in healthy normal subjects, either in the control group or as a primary objective of the study. Data were combined using a random-effects model, and effects of demographic, hemodynamic, and equipment variables were sought in a meta-regression.
The search identified 2,597 subjects from 24 studies. Reported normal values of GLS varied from -15.9% to -22.1% (mean, -19.7%; 95% CI, -20.4% to -18.9%). Normal global circumferential strain varied from -20.9% to -27.8% (mean, -23.3%; 95% CI, -24.6% to -22.1%). Global radial strain ranged from 35.1% to 59.0% (mean, 47.3%; 95% CI, 43.6% to 51.0%). There was significant between-study heterogeneity and inconsistency. The source of variation was sought between studies using meta-regression. Blood pressure, but not age, gender, frame rate, or equipment, was associated with variation in normal GLS values.
The narrowest confidence intervals from this meta-analysis were for GLS and global circumferential strain, but individual studies have shown a broad range of strain in apparently normal subjects. Variations between different normal ranges seem to be associated with differences in systolic blood pressure, emphasizing that this should be considered in the interpretation of strain.
The aim of this study was to identify the best echocardiographic method for sequential quantification of left ventricular (LV) ejection fraction (EF) and volumes in patients undergoing cancer ...chemotherapy.
Decisions regarding cancer therapy are based on temporal changes of EF. However the method for EF measurement with the lowest temporal variability is unknown.
We selected patients in whom stable function in the face of chemotherapy for breast cancer was defined by stability of global longitudinal strain (GLS) at up to 5 time points (baseline, 3, 6, 9, and 12 months). In this way, changes in EF were considered to reflect temporal variability of measurements rather than cardiotoxicity. A comprehensive echocardiogram consisting of 2-dimensional (2D) and 3-dimensional (3D) acquisitions with and without contrast administration was performed at each time point. Stable LV function was defined as normal GLS (≤-16.0%) at each examination. The EF and volumes were measured with 2D-biplane Simpson's method, 2D-triplane, and 3-dimensional echocardiography (3DE) by 2 investigators blinded to any clinical data. Inter-, intra-, and test-retest variability were assessed in a subgroup. Variability was assessed by analysis of variance and compared with Levene's or t test.
Among 56 patients (all female, 54 ± 13 years of age), noncontrast 3D EF, end-diastolic volume, and end-systolic volume had significantly lower temporal variability than all other methods. Contrast only decreased the temporal variability of LV end-diastolic volume measurements by the 2D biplane method. Our data suggest that a temporal variability in EF of 0.06 might occur with noncontrast 3DE due to physiological differences and measurement variability, whereas this might be >0.10 with 2D methods. Overall, 3DE also had the best intra- and inter-observer as well as test-retest variability.
Noncontrast 3DE was the most reproducible technique for LVEF and LV volume measurements over 1 year of follow-up.
Right ventricular (RV) systolic strain has recently demonstrated prognostic value in various cardiovascular diseases. Despite this, the reference range including the lower limit of normal (LLN) and ...factors associated with RV strain measurements are not well-established. This meta-analysis aimed to determine the mean and LLN of two- (2D) and three-dimensional (3D) right ventricular global (RVGLS), free wall (RVFWLS) and interventricular septal wall (IVSLS) longitudinal strains in healthy individuals and factors that affect strain measurements.
In this meta-analysis, Pubmed, Embase and Cochrane databases were searched until 31 July 2020 for eligible studies reporting RVGLS, RVFWLS and/or IVSLS in at least 30 healthy subjects. We pooled the means and LLNs of RV strains by two- (2D) and three- (3D) dimensional echocardiography, and performed meta-regression analyses.
From 788 articles screened, 45 eligible studies totaling 4439 healthy subjects were eligible for analysis. Pooled means and LLNs with 95% confidence intervals for 2D- RV strains were RVGLS -23.4% (-24.2%, -22.6%) and -16.4% (-17.3%, -15.5%) in 27 studies; RVFWLS -26.9% (-28.0%, -25.9%) and -18.0% (-19.2%, -16.9%) in 32 studies; and IVSLS -20.4% (-22.0%, -18.9%) and -11.5% (-13.6%, -9.6%) in 10 studies, and similar results for 3D- RV strains. Right ventricular fractional area change and vendor software were associated with 2D-RVGLS and RVFWLS means and LLNs.
We reported the pooled means and LLNs of RV systolic strains in healthy subjects, to define thresholds for abnormal, borderline and normal strains. Important factors associated with RV systolic strains include right ventricular fractional area change and vendor software.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We tested the hypothesis that right ventricular (RV) pressure overload affects RV function and further influences left ventricular (LV) geometry, which adversely affects LV twist mechanics and ...segmental function.
Echocardiographic images were prospectively acquired in 44 patients (age, 46+/-12 years; 82% women) with evidence of pulmonary hypertension (estimated pulmonary artery systolic pressure, 71+/-23 mm Hg) and in 44 age- and gender-matched healthy subjects. Patients with intrinsic LV diseases were excluded. RV lateral wall longitudinal strain (LS) and interventricular septal (IVS) LS were reduced in the pulmonary hypertension group compared with control subjects (-15.9+/-7.6% versus -25.5+/-6.1%, P<0.001; and -17.3+/-4.4% versus -20.2+/-3.9%, P=0.002, respectively), whereas LV lateral wall LS was preserved. RV lateral wall LS and IVS LS, but not LV lateral wall LS, correlated with pulmonary artery systolic pressure (r=0.56, P<0.01; r=0.32, P<0.01) and LV eccentricity index (r=0.57, P<0.01; r=0.57, P<0.01). IVS and LV lateral wall circumferential strain (CS) were both reduced in the pulmonary hypertension group. Although IVS CS and LV lateral wall CS correlated with pulmonary artery systolic pressure and LV eccentricity index, after adjustment of CS for LV eccentricity index, differences between groups persisted for IVS CS (P<0.01) but not LV lateral wall CS (P=0.09). LV torsion was decreased in patients with pulmonary hypertension compared with control subjects (9.6+/-4.9 degrees versus 14.7+/-4.9 degrees , P<0.001). LV torsion inversely correlated with pulmonary artery systolic pressure (r=-0.39, P<0.01) and LV eccentricity index (r=-0.3, P<0.01). LV untwisting rates were similar in both groups (P=0.7).
Chronic RV pressure overload directly affects RV longitudinal systolic deformation. RV pressure overload further influences IVS and LV geometry, which impairs LV torsion and segmental LS and CS, more for the IVS than for the free wall of the LV.
Some form of the assessment of observer variability may be the most frequent statistical task in medical literature. Still, very little attempt is made to make the reported methods uniform and clear ...to the reader. This paper provides overview of various measures of observer variability, and a rationale of why using standard error of measurement (SEM) is preferable to other measures of observer variability. The supplemental file contains examples on how to design a proper repeatability and reproducibility assessment, determine appropriate sample size, and test for significance of its findings.
Background An updated 2016 echocardiographic algorithm for diagnosing left ventricular (LV) diastolic dysfunction (DD) was recently proposed. We aimed to assess the reliability of the 2016 ...echocardiographic LVDD grading algorithm in predicting elevated LV filling pressure and clinical outcomes compared to the 2009 version. Methods We retrospectively identified 460 consecutive patients without atrial fibrillation or significant mitral valve disease who underwent transthoracic echocardiography within 24 hours of elective heart catheterization. LV end-diastolic pressure (LVEDP) and the time constant of isovolumic pressure decay (Tau) were determined. The association between DD grading by 2009 LVDD Recommendations and 2016 Recommendations with hemodynamic parameters and all-cause mortality were compared. Results The 2009 LVDD Recommendations classified 55 patients (12%) as having normal, 132 (29%) as grade 1, 156 (34%) as grade 2, and 117 (25%) as grade 3 DD. Based on 2016 Recommendations, 177 patients (38%) were normal, 50 (11%) were indeterminate, 124 (27%) patients were grade 1, 75 (16%) were grade 2, 26 (6%) were grade 3 DD, and 8 (2%) were cannot determine. The 2016 Recommendations had superior discriminatory accuracy in predicting LVEDP ( P < .001) but were not superior in predicting Tau. During median follow-up of 416 days (interquartile range: 5 to 2004 days), 54 patients (12%) died. Significant DD by 2016 Recommendations was associated with higher risk of mortality ( P = .039, subdistribution HR1.85 95% CI, 1.03-3.33) in multivariable competing risk regression. Conclusions The grading algorithm proposed by the 2016 LV diastolic dysfunction Recommendations detects elevated LVEDP and poor prognosis better than the 2009 Recommendations.
Left atrial (LA) strain (epsilon) and epsilon rate (SR) analysis by two-dimensional speckle tracking can represent a new tool to evaluate LA function. To assess its potential value, the authors ...addressed whether LA epsilon and SR measured in normal subjects correlates with other Doppler echocardiographic parameters that evaluate LA function and left ventricular function.
Sixty-four healthy subjects were studied. LA epsilon and SR were calculated with the reference point set at the P wave, which enabled the recognition of peak negative epsilon (epsilon(neg peak)), peak positive epsilon (epsilon(pos peak)), and the sum of those values, total LA epsilon (epsilon(tot)), corresponding to LA contractile, conduit, and reservoir function, respectively. Similarly, peak negative SR (LA SR(late neg peak)) during LA contraction, peak positive SR (LA SR(pos peak)) at the beginning of LV systole, and peak negative SR (LA SR(early neg peak)) at the beginning of LV diastole were identified.
Global LA epsilon(pos peak), epsilon(neg peak), and epsilon(tot) were 23.2 +/- 6.7%, -14.6 +/- 3.5%, and 37.9 +/- 7.6%, respectively. Global LA SR(pos peak), SR(early neg peak) , and SR(late neg peak) were 2.0 +/- 0.6 s(-1), -2.0 +/- 0.6 s(-1), and -2.3 +/- 0.5 s(-1), respectively. The above-described variables derived from analysis of global LA epsilon and LA SR correlated significantly with Doppler echocardiographic indexes that evaluated the same phase of the cardiac cycle or the same component of the LA function, including indexes derived from mitral inflow, pulmonary vein velocities, tissue Doppler, and LA volumes. Global LA epsilon(pos peak), LA epsilon(tot), and LA SR(early neg peak) also correlated significantly with age or body mass index. Global LA SR(late neg peak) also correlated significantly with age.
LA epsilon analysis is a new tool that can be used to evaluate LA function. Further studies are warranted to determine the utility of LA epsilon in disease states.
Autonomic dysfunction, characterized by sympathetic activation and vagal withdrawal, contributes to the progression of heart failure (HF). Although the therapeutic benefits of sympathetic inhibition ...with beta-blockers in HF are clear, the role of increased vagal tone in this setting has been less studied. We have investigated the impact of enhancing vagal tone (achieved through chronic cervical vagus nerve stimulation, VNS) on HF development in a canine high-rate ventricular pacing model.
Fifteen dogs were randomized into control (n=7) and VNS (n=8) groups. All dogs underwent 8 weeks of high-rate ventricular pacing (at 220 bpm for the first 4 weeks to develop HF and another 4 weeks at 180 bpm to maintain HF). Concomitant VNS, at an intensity reducing sinus rate approximately 20 bpm, was delivered together with the ventricular pacing in the VNS group. At 4 and 8 weeks of ventricular pacing, both left ventricular end-diastolic and -systolic volumes were lower and left ventricular ejection fraction was higher in the VNS group than in the control group. Heart rate variability and baroreflex sensitivity improved in the VNS dogs. Rises in plasma norepinephrine, angiotensin II, and C-reactive protein levels, ordinarily expected in this model, were markedly attenuated with VNS treatment.
Chronic VNS improves cardiac autonomic control and significantly attenuates HF development in the canine high-rate ventricular pacing model. The therapeutic benefit of VNS is associated with pronounced anti-inflammatory effects. VNS is a novel and potentially useful therapy for treating HF.
Post-systolic shortening index (PSI) is defined as myocardial shortening that occurs after aortic valve closure, and is an emerging measure of regional LV contractile dysfunction. PSI measurement ...variability amongst software vendor and its relationship with mechanical dyssynchrony and mechanical dispersion index (MDI) remains unknown. We evaluated PSI by speckle-tracking echocardiography from several vendors in patients with increased left ventricular wall thickness, and associations with MDI. This is a prospective cross-sectional study of 70 patients (36 hypertrophic cardiomyopathy HCM, 18 cardiac amyloidosis and 16 healthy controls) undergoing clinically indicated echocardiography. PSI was measured using QLAB/aCMQ (Philips), QLAB/LV auto-trace (Philips), EchoPAC (GE), Velocity Vector Imaging (Siemens), and EchoInsight (EPSILON) software packages, and calculated as 100%x(post systolic strain-end-systole strain)/post systolic strain. There was a significant difference in mean PSI among controls 2.1±0.6%, HCM 6.1±2.6% and cardiac amyloidosis 6.8±2.7% (p <0.001). Variations between software vendors were significant in patients with pathologic increases in LV wall thickness (for HCM p = 0.03, for amyloidosis p = 0.008), but not in controls (p = 0.11). Furthermore, there were moderate correlations between PSI and both MDI (r = 0.77) and left ventricular global longitudinal strain (r = 0.69). PSI was greater in HCM and cardiac amyloidosis patients than controls, and a valuable tool for dyssynchrony evaluation, with moderate correlations to MDI and strain. However, there were significant variations in PSI measurements by software vendor especially in patients with pathological increase in LV wall thickness, suggesting that separate vendor-specific thresholds for abnormal PSI are required.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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