Echocardiographic strain and strain rate imaging — Clinical applications

Fetal left and right ventricular strain parameters using speckle tracking in congenital heart diseases

Assessment of fetal ventricular function is mostly subjective, and currently, for the objective assessment left ventricular shortening fraction is obtained. However, this by itself is not very reliable. Hence, more tools that can provide an objective assessment are needed to increase the confidence of functional assessment. Speckle tracking imaging can provide one such tool. In this study we sought to establish the normative value of global longitudinal and circumferential strain for our fetal patients and for two major forms of congenital heart diseases, namely atrioventricular canal defects (AVC) and uncorrected dextro-transposition of the great arteries (dTGA) to act as a benchmark. The study was completed via a single center retrospective analysis on 72 fetal echocardiograms (26 normal, 15 dTGA, and 31 AVC). Tomtec Arena™ echocardiography analysis software was used for analysis. In normal fetuses, mean left ventricular (LV) global longitudinal strain (GLS) was - 22.6% (95% CI -24, -21.1) and mean right ventricular (RV) GLS was - 22.1% (95% CI -23.6, -20.6). In AVC patients LV GLS was-26.6% (95% CI -28,-25.3) and mean RV GLS was - 26.5% (95% CI -27.9,-25.2). In dTGA patients LV GLS was - 22.9% (95% CI of -24.8, -21) and RV GLS was - 21.3% (95% CI was - 23.4, -20.8). There was good intra-rater reliability though poor to fair inter-rater reliability. Notwithstanding its current limitations, strain imaging can provide useful information that can increase confidence of cardiac functional assessment in fetal patients. However, to be reliable across the board, further automation and standardization is required.

A Comprehensive Excursus of the Roles of Echocardiography in Heart Transplantation Follow-Up

Current guidelines for the care of heart transplantation recipients recommend routine endomyocardial biopsy and invasive coronary angiography as the cornerstones in the surveillance for acute rejection (AR) and coronary allograft vasculopathy (CAV). Non-invasive tools, including coronary computed tomography angiography and cardiac magnetic resonance, have been introduced into guidelines without roles of their own as gold standards. These techniques also carry the risk of contrast-related kidney injury. There is a need to explore non-invasive approaches providing valuable information while minimizing risks and allowing their application independently of patient comorbidities. Echocardiographic examination can be performed at bedside, serially repeated, and does not carry the burden of contrast-related kidney injury and procedure-related risk. It provides comprehensive assessment of cardiac morphology and function. Advanced echocardiography techniques, including Doppler tissue imaging and strain imaging, may be sensitive tools for the detection of minor myocardial dysfunction, thus providing insight into early detection of AR and CAV. Stress echocardiography may offer a valuable tool in the detection of CAV, while the assessment of coronary flow reserve can unravel coronary microvascular impairment and add prognostic value to conventional stress echocardiography. The review highlights the role of Doppler echocardiography in heart transplantation follow-up, weighting advantages and limitations of the different techniques.

Influence of Power-Weighted Center of Echo Signal Within Window Function on Local Strain Rate Distribution in Left Ventricular Wall

OBJECTIVE

The deviation of the power-weighted center of the echo signal from the geometric center within the velocity estimation window for calculating strain rate (SR) causes an estimation error. This study aimed to confirm whether an erroneous multilayer pattern in the SR distribution of the left ventricular wall could be corrected by considering the power-weighted center of the echo signal.

METHODS

The SR distributions were measured locally in the transmural direction around the pre-ejection and early diastolic phases in healthy volunteers. The estimation error related to the power-weighted center of the echo signal was corrected using a previously proposed method, and the effectiveness of the correction was confirmed based on the accuracy of the estimated myocardial displacement.

RESULTS

The SR distribution in early diastole was observed as multilayers of low- and high-amplitude negative SRs. However, this multilayer pattern disappeared after correction. In the pre-ejection phase, multilayers of positive and negative SRs were observed in the SR distributions with and without correction. This correction was sufficiently effective in accurately tracking the local peak of the echo signal.

CONCLUSION

The multilayer pattern of low- and high-amplitude positive or negative SRs is caused by estimation errors related to the power-weighted center of the echo signal. The multilayer pattern of positive and negative SRs might not be caused by these errors and might relate to the actual change in myocardial thickness because the estimation errors do not convert the negative (positive) SR to positive (negative) in a homogeneous negative (positive) SR distribution.

The usefulness of global longitudinal peak strain and left atrial volume index in predicting atrial fibrillation in patients with ischemic stroke

Introduction

Detection of atrial fibrillation (AF) is crucial for preventing recurrence in patients with ischemic stroke. We aimed to examine whether the left atrial volume index (LAVI) and global longitudinal peak strain (GLPS) are associated with AF in patients with ischemic stroke.

Methods

We prospectively analyzed 678 consecutive patients with ischemic stroke. LAVI and GLPS were assessed using three-dimensional transthoracic echocardiography with speckle-tracking imaging. Multiple logistic regression was used to evaluate the association of AF with LAVI and GLPS. To evaluate the predictive value of LAVI and GLPS for the presence of AF, we used optimism-corrected c-statistics calculated by 100 bootstrap repetitions and the net reclassification improvement (NRI).

Results

The mean patient age was 68 ± 13 years (men, 60%). Patients with AF (18%) were a higher LAVI (41.7 ml/m2 vs. 74.9 ml/m2, P < 0.001) and a higher GLPS than those without AF (-14.0 vs. -17.3, P < 0.001). Among the 89 patients classified with embolic stroke of unknown source, the probable cardioembolic group had higher GLPS (n= 17, -14.6 vs. -18.6, respectively; P= 0.014) than the other groups (n= 72). Adding GLPS to age, hypertension, and the LAVI significantly improved the NRI, with an overall NRI improvement of 6.1% (P= 0.03).

Discussion

The LAVI andGLPS with speckle-tracking imaging echocardiography may help identify patients with AF.

Strain imaging as an early predictor in acute myocardial infarction - An augmented cross-sectional study

INTRODUCTION

Cardiac fibres are affected invariably in myocardial infarction, with longitudinal strain being the earliest to be detected in the ischaemic cascade. The present study aims to assess strain imaging in acute myocardial infarction (AMI) patients admitted to the cardiology department at our institute and correlate GLS and DESL findings with other markers for myocardial function.

METHODS AND MATERIAL

This augmented cross-sectional study was conducted amongst the patients admitted with diagnosis of AMI. During the study period, 157 subjects were sampled through convenience sampling, and examined as well as tested with routine investigations at baseline. The subjects were then followed through at first, third and six months, and findings noted. Chi-square was used to assess the crude association between sample characteristics. Pearson correlation and student t-test were used to find association between continuous variables.

RESULTS

After screening 564 patients, 157 patients were included in the study after fulfilment of inclusion and exclusion criteria. A significant difference was found in baseline GLS scores and NTproBNP levels at 6 months in alive patients with STEMI, t (21.728) = -5.717, p < .001. Out of the 50 NSTEMI patients, 35 (70 %) were positive for ESL, similarly out of 43 STEMI patients without any RWMA, ESL was positive in 39 (90.02 %) patients.

CONCLUSIONS

GLS by STE has good correlation with LVEF, WMSI and NT pro-BNP and it is an independent predictor of mortality and heart failure among patients with AMI.

Reliability and validity of ultrasonography in evaluating the thickness, excursion, stiffness, and strain rate of respiratory muscles in non-hospitalized individuals: a systematic review

OBJECTIVE

To summarize the reliability and validity of ultrasonography in evaluating the stiffness, excursion, stiffness, or strain rate of diaphragm, intercostals and abdominal muscles in healthy or non-hospitalized individuals.

LITERATURE SEARCH

PubMed, Embase, SPORTDiscus, CINAHL and Cochrane Library were searched from inception to May 30, 2022.

STUDY SELECTION CRITERIA

Case-control, cross-sectional, and longitudinal studies were included if they investigated the reliability or validity of various ultrasonography technologies (e.g., brightness-mode, motion-mode, shear wave elastography) in measuring the thickness, excursion, stiffness, or strain rate of any respiratory muscles.

DATA SYNTHESIS

Relevant data were summarized based on healthy and different patient populations. The methodological quality by different checklist depending on study design. The quality of evidence of each psychometric property was graded by the Grading of Recommendations, Assessment, Development and Evaluations, respectively.

RESULTS

This review included 24 studies with 787 healthy or non-hospitalized individuals (e.g., lower back pain (LBP), adolescent idiopathic scoliosis (AIS), and chronic obstructive pulmonary disease (COPD)). Both inspiratory (diaphragm and intercostal muscles) and expiratory muscles (abdominal muscles) were investigated. Moderate-quality evidence supported sufficient (intra-class correlation coefficient > 0.7) within-day intra-rater reliability of B-mode ultrasonography in measuring right diaphragmatic thickness among people with LBP, sufficient between-day intra-rater reliability of M-mode ultrasonography in measuring right diaphragmatic excursion in non-hospitalized individuals. The quality of evidence for all other measurement properties in various populations was low or very low. High-quality evidence supported sufficient positive correlations between diaphragm excursion and forced expiratory volume in the first second or forced vital capacity (r >  = 0.3) in healthy individuals.

CONCLUSIONS

Despite the reported sufficient reliability and validity of using ultrasonography to assess the thickness, excursion, stiffness, and strain rate of respiratory muscles in non-hospitalized individuals, further large-scale studies are warranted to improve the quality of evidence regarding using ultrasonography for these measurements in clinical practice. Researchers should establish their own reliability before using various types of ultrasonography to evaluate respiratory muscle functions.

TRIAL REGISTRATION

PROSPERO NO. CRD42022322945.

Early detection of reduced left ventricular systolic function by 2D speckle tracking echocardiography in patients with primary mitral regurgitation in a Vietnamese cohort

Background: Mitral regurgitation (MR) is a common heart valve disease, causing many serious complications in several organ systems, especially the cardiovascular system. The 2D speckle tracking echocardiography (STE) is a new technique for detecting potential cardiac dysfunction when only tissue function abnormalities are present. The study aimed to assess left ventricular (LV) systolic function early by STE in patients with primary MR through global LV deformity along the global longitudinal strain (GLS). Methods: An analytical cross-sectional study was performed on 46 patients with moderate to severe primary MR as recommended by the American Society of Echocardiography (ASE) 2017. Results: The prevalence of patients with GLS reduction with ejection fraction (EF) >60%, New York Heart Association (NYHA) I, and left ventricular internal diameter systolic (LVIDs) <40 mm was 38.1%, 35.7%, and 39.5%, respectively. 100% of patients with EF<60% and LVIDs ≥40 mm had reduced GLS (<16%). The GLS index strongly correlates with the NYHA classification, degree of MR, EF, and echocardiographic parameters. Conclusion: GLS index gives a significant sign in the early detection of cardiac function abnormalities before symptoms or other echocardiographic parameters in patients with MR.

Three-Dimensional-Derived Echocardiographic Left Ventricular Structure and Function and Indices from the 12-Lead Electrocardiogram across the Menstrual Cycle in Healthy Physically Active Females: An Exploratory Study

Background: The impact of the menstrual phases on left ventricular (LV) structure and function using 3D echocardiography and resting electrocardiogram (ECG) in healthy, eumenorrheic, and physically active females has not been investigated. Methods: sixteen females (20 y ± 2) underwent 3D echocardiography and an ECG at three time points in the menstrual cycle phases (follicular, ovulation, luteal). LV end-diastolic volume (LVEDVi), LV ejection fraction (LVEF), LV mass allometrically indexed to height2.7 (LVMi), torsion, and global longitudinal, circumferential, and radial strain (GLS, GCS, and GRS) were evaluated. ECG data of the P and QRS waves were presented as well as axis deviation, chamber enlargement, and any rhythm abnormalities. Results: LVMi was significantly higher in the luteal phase (36.4 g/m2.7 ± 3.3) compared to the follicular (35.0 g/m2.7 ± 3.7) and ovulation (34.7 g/m2.7 ± 4.3) phases (p = 0.026). There were no differences in other indices of LV structure and function or ECG variables across all phases of the menstrual cycle or evidence of arrhythmia. Conclusions: In physically active females, there is a small but significantly higher LVMi associated with the luteal phase of the menstrual cycle with no concomitant change in LV function or ECG parameters. These findings are important to consider when conducting clinical or research serial assessments.

Inflammatory cytokines and their correlations with different left ventricular geometries and functions in PHT patients

OBJECTIVES

To investigate relationships between hypersensitive C-reactive protein (hs-CRP), tumor necrosis factor -α (TNF-α), interleukin-17A (IL-17A), and interferon -γ (IFN-γ), with left ventricular geometry (LVG) and function in patients with primary hypertension (PHT).

METHODS

A total of 396 PHT patients were assigned into four groups: Normal Geometry (NG), Concentric Remodeling (CR), Eccentric Hypertrophy (EH), and Concentric Hypertrophy (CH). The correlation between hs-CRP, TNF-α, IL-17A, IFN-γ, and clinical, biochemical parameters were analyzed by Pearson correlation analysis and Logistic regression. Receiver Operating Characteristic (ROC) curve was used to analyze the clinical values of hs-CRP, TNF-α, IL-17A, and IFN-γ for abnormal LVG prediction.

RESULTS

NG, CR, EH, and CH group all presented increasingly higher levels of Hs-CRP, TNF-α, IL-17A, and IFN-γ, and the increase was the most prominent in the CH group. Pearson correlation analysis showed that hs-CRP, IL-17A, and IFN-γ were all positively correlated with LASct. Hs-CRP, TNF-α, and IL-17A were all negatively correlated with GLS, LASr, and LAScd. However, IFN-γ was only negatively correlated with GLS and LAScd. Logistic regression analysis showed that hs-CRP and IL-17A were independently correlated with CR; hs-CRP, TNF-α, IFN-γ, and IL-17A were independently correlated with EH and CH. ROC curve analysis showed that the area under the curve (AUC) of hs-CRP was 0.816. When the optimal diagnostic threshold of hs-CRP was 3.04 mg/L, the sensitivity and specificity of the abnormal LVG were 72.1% and 81.5%, respectively.

CONCLUSION

In PHT patients, hs-CRP, TNF-α, IL-17A, and IFN-γ were correlated with abnormal LVG and left ventricular function, suggesting that inflammatory cytokines may be involved in the process of PHT-induced abnormal left ventricular structure and function. In addition, hs-CRP can be used as a health screening index for patients at high risk of abnormal LVG.

Assessment of Cardiotoxicity after a Single Dose of Combretastatin A4-Phosphate in Dogs Using Two-Dimensional Speckle-Tracking Echocardiography

Simple Summary

Combretastatin A4-phosphate is a chemotherapeutic drug which has been evaluated for treatment of solid canine tumors. Previous studies reported cardiotoxic effects based on changes in cardiac troponin I measurements, blood pressure, and electrocardiography. We evaluated the cardiotoxic effect by two-dimensional speckle tracking echocardiography. This advanced imaging technique analyzes global and regional myocardial function and is used as the gold-standard for the assessment of cardiac function in human patients receiving chemotherapy. We found that certain strain measurements were significantly decreased 24 h after the administration of combretastatin A4-phosphate and that these changes were correlated with an increase in cardiac troponin I. Our results suggest that two-dimensional speckle tracking may be useful for the early detection of cardiac dysfunction in canine cancer patients as well as promising during follow-up.

Abstract

Combretastatin A4-phosphate (CA4P) is a vascular disrupting agent that was recently described for the treatment of solid canine tumors. Conventional echocardiography and pulsed wave tissue Doppler imaging did not reveal cardiotoxicity in dogs, however, the gold standard for assessing myocardial damage in humans receiving cardiotoxic chemotherapeutics is two-dimensional speckle-tracking echocardiography. The current study evaluated the cardiotoxic effect of a single dose of CA4P in dogs using peak systolic strain measurements and the variability of these measurements. Echocardiographic examinations of seven healthy beagles and five canine cancer patients that received CA4P were retrospectively reviewed. Peak systolic regional longitudinal strain (LSt), peak systolic regional circumferential strain (CSt), and peak systolic regional radial strain (RSt) were measured before and 24 h after administration of CA4P. Peak systolic strain measurements were compared to serum cardiac troponin I (cTnI). To quantify intra- and inter-observer measurement variability, seven echocardiographic examinations were selected and each strain parameter was measured by three observers on three consecutive days. After CA4P administration, the median LSt and CSt values decreased by 21.8% (p = 0.0005) and 12.3% (p = 0.002), respectively, whereas the median RSt values were not significantly different (p = 0.70). The decrease in LSt was correlated with increased serum cTnI values (Spearman rho = −0.64, p = 0.02). The intra-observer coefficients of variation (CV) were 9%, 4%, and 13% for LSt, CSt, and RSt, respectively, while the corresponding interobserver CVs were 11%, 12%, and 20%. Our results suggest that regional peak systolic strain measurements may be useful for the early detection of cardiotoxicity that is caused by vascular disrupting agents and that LSt may be promising for the follow-up of canine cancer patients.

LVAD as a Bridge to Remission from Advanced Heart Failure: Current Data and Opportunities for Improvement

Left ventricular assist devices (LVADs) are an established treatment modality for advanced heart failure (HF). It has been shown that through volume and pressure unloading they can lead to significant functional and structural cardiac improvement, allowing LVAD support withdrawal in a subset of patients. In the first part of this review, we discuss the historical background, current evidence on the incidence and assessment of LVAD-mediated cardiac recovery, and out-comes including quality of life after LVAD support withdrawal. In the second part, we discuss current and future opportunities to promote LVAD-mediated reverse remodeling and improve our pathophysiological understanding of HF and recovery for the benefit of the greater HF population.

Prognostic Value of Left and right ventricular deformation strain analysis on Acute Cellular rejection in Heart Transplant recipients: A 6-year outcome study

PURPOSE

Two-dimensional (2D) strain analysis is a sensitive method for detecting myocardial dysfunction in acute cellular rejection (ACR) from post-transplant complications. This study aims to evaluate the utility of novel left (LV) and right ventricular (RV) strain parameters for prognostic risk stratification associated with ACR burden at 1-year post transplantation.

METHODS

128 Heart transplant patients, assessed between 2012 and 2018, underwent transthoracic echocardiography and endomyocardial biopsy. 2D strain analysis was performed and history of rejection burden was assessed and grouped according to ACR burden at 1-year post transplantation. The primary endpoint was all-cause mortality at 6-years follow up.

RESULTS

21 patients met primary the endpoint. Multivariate analysis of 6-year all-cause mortality showed LV global longitudinal strain (LV GLS) (Hazard Ratio [HR] = 1.21, CI = 1.06-1.49), LV early diastolic strain rate (LV ESr) (HR = 1.31, CI = 1.12-1.54), RV GLS (HR = 1.12, CI = 1.02-1.25) and RV ESr (HR = 1.26, CI = 1.12-1.47) were significant predictors of outcome. Univariate analysis also showed LV GLS, LV ESr, RV GLS and RV ESr were significant predictors of outcome. Optimal cut-off for predicting 6-year mortality for LV GLS by receive operator characteristic was 15.5% (sensitivity: 92%, specificity: 79%). Significant reductions (p < 0.05) in LV GLS, RV GLS and LV and RV ESr between rejection groups were seen.

CONCLUSIONS

Non-invasive LV and RV strain parameters are predictors of mortality in post-transplant patient with ACR. LV GLS and LV ESr are superior to other strain and conventional echo parameters.

Chest conformation spuriously influences strain parameters of myocardial contractile function in healthy pregnant women

AIMS

Left ventricular (LV) contractility during noncomplicated pregnancy has been previously investigated by two-dimensional speckle-tracking echocardiography (2D-STE), with conflicting results. Chest abnormalities might affect myocardial strain parameters, yet this issue has not been previously investigated during pregnancy. We evaluated the influence of chest conformation on myocardial strain parameters in healthy pregnant women.

METHODS

Between October 2019 and February 2020, 50 healthy pregnant women (32.3 ± 4.0 years old) were consecutively studied. They underwent obstetric visit, assessment of chest shape by modified Haller index (MHI; chest transverse diameter over the distance between sternum and spine) and transthoracic echocardiography implemented with 2D-STE analysis of all myocardial strain parameters in the first trimester (12-14 weeks), third trimester (36-38 weeks) and 6-9 weeks after delivery.

RESULTS

LV ejection fraction remained substantially unchanged (P = 0.13), while on the average all myocardial strain parameters showed a small but significant decrease during pregnancy, and recovered postpartum (all P < 0.001). Women with concave-shaped chest wall (MHI > 2.5, n = 29), and those with normal chest conformation (MHI ≤ 2.5, n = 21) were then separately analyzed. Pregnant women with MHI above 2.5, but not those with MHI 2.5 or less, showed a progressive but reversible decrease in all myocardial strain parameters (all P < 0.001). MHI was strongly correlated with LV global longitudinal strain (r = -0.87) and LV global circumferential strain (r = -0.83) in the third trimester of pregnancy.

CONCLUSION

Myocardial strain impairment during healthy pregnancy may not reflect intrinsic myocardial dysfunction but rather intraventricular dyssynchrony related to a narrow antero-posterior chest diameter and rise in the diaphragm, with consequent extrinsic myocardial compression.

Screening for dilated cardiomyopathy in dogs

BACKGROUND

Dilated cardiomyopathy (DCM) is the most common cardiac disease in large breed dogs. The disease can start with arrhythmias or with systolic dysfunction of the myocardium.

OBJECTIVE

To describe screening methods for DCM in various breeds and provide a new, modified staging system.

RECOMMENDATIONS

Screening for occult DCM should start at three years of age and use Holter monitoring in Boxers and Dobermans and might be useful also in other breeds. Single ventricular premature complexes (VPCs) can be detected in many healthy dogs, but healthy animals typically have <50 VPCs in 24 h and demonstrate minimal complexity most often occurring only as single ectopic beats. In general, >100 VPCs in 24 h was recommended as the cut-off value for establishing a diagnosis of DCM. However, there are breed-specific recommendations related to Holter recording diagnosis of DCM in Dobermans and Boxers. Yearly screening over the life of a dog is recommended, as a one-time screening is not sufficient to rule out the future development of DCM. Several echocardiographic methods such as M-mode derived measurements, the measurement of the left ventricular (LV) volume by Simpson's method of discs (SMOD), and E-point to septal separation (EPSS) are recommended for screening purposes. The value of additional tests such as cardiac biomarkers (troponin I and N-terminal pro-B-type natriuretic peptide) as well as a 5-min resting electrocardiogram (ECG) or newer echocardiographic methods such as strain measurements is discussed.

CONCLUSION

This review suggests some guidelines for screening for DCM in various breeds.

Mechanical concordance between left atrium and left atrial appendage in nonvalvular atrial fibrillation: can it be exploited to avoid transesophageal echocardiography prior to electrical cardioversion during Covid-19 pandemic?

Transesophageal echocardiography (TEE) is the gold standard for assessing left atrial appendage (LAA) mechanic and thrombosis (LAAT); however, TEE is a high-risk procedure for viral transmission during coronavirus disease 2019 (COVID-19) pandemic. We investigated whether deformation indices of left atrium (LA) at transthoracic echocardiography (TTE) correlate with those of LAA assessed by TEE in nonvalvular atrial fibrillation (NVAF) patients undergoing electrical cardioversion (ECV). Consecutive patients with NVAF of ≥ 48 h or unknown duration, who underwent TEE and TTE at our Institution before ECV were retrospectively investigated. Standard echo-Doppler and LA and LAA myocardial strain and strain rate parameters were analyzed. A total of 115 NVAF patients (71.3 ± 8.1 yr/o, 59.1% men) were included: LAAT was diagnosed in 25 (21.7%) patients. Compared to patients without LAAT, those with LAAT had significantly higher CHA₂DS₂-VASc Risk score (4.5 ± 1.4 vs. 3.5 ± 1.1, p < 0.001), and lower ejection fraction (46.0 ± 14.8 vs. 57.6 ± 8.6%, p < 0.001). In LAAT patients, global strain of LA (8.7 ± 2.6 vs. 16.3 ± 4.5%, p < 0.001) and LAA (7.0 ± 1.7 vs. 11.7 ± 2.0%, p < 0.001) was significantly reduced compared to non-LAAT patients. A close relationship between left atrial strain reservoir (LASr) and LAA-global strain was demonstrated (r = 0.81). By univariable analysis, CHA₂DS₂-VASc Risk Score (OR 2.01, 95%CI 1.34–3.00), NT-proBNP (OR 1.36, 95%CI 1.19–1.54), ejection fraction (OR 0.92, 95%CI 0.88–0.96), E/e’ ratio (OR 2.07, 95%CI 1.51–2.85), and LASr (OR 0.39, 95%CI 0.25–0.62) were strongly associated with LAAT presence at TEE. By multivariable analysis, only LASr (OR 0.40, 95%CI 0.24–0.70) retained statistical significance. ROC curve analysis revealed that an LASr cut-off value ≤ 9.3% had 98.9% sensibility and 100% specificity to identify LAAT by TEE (AUC = 0.98). In patients with NVAF of ≥ 48 h or unknown duration, scheduled to undergo ECV, LA deformation assessment by TTE might substitute invasive measurement of LAA function by TEE, simplifying diagnostic approach and possibly contributing to reduce COVID-19 infection diffusion.

The role of non-invasive imaging modalities in cardiac allograft vasculopathy: an updated focus on current evidences

Cardiac allograft vasculopathy (CAV) is an obliterative and diffuse form of vasculopathy affecting almost 50% of patients after 10 years from heart transplant and represents the most common cause of long-term cardiovascular mortality among heart transplant recipients. The gold standard diagnostic technique is still invasive coronary angiography, which however holds potential for complications, especially contrast-related kidney injury and procedure-related vascular lesions. Non-invasive and contrast-sparing imaging techniques have been advocated and investigated over the past decades, in order to identify those that could replace coronary angiography or at least reach comparable accuracy in CAV detection. In addition, they could help the clinician in defining optimal timing for invasive testing. This review attempts to examine the currently available non-invasive imaging techniques that may be used in the follow-up of heart transplant patients, spanning from echocardiography to nuclear imaging, cardiac magnetic resonance and cardiac computed tomography angiography, weighting their advantages and disadvantages.

Role of Two-Dimensional Speckle-Tracking Echocardiography in Early Detection of Left Ventricular Dysfunction in Dogs

Simple Summary

Two-dimensional speckle-tracking echocardiography represents an advanced imaging technique that allows the analysis of global and regional myocardial function, cardiac rotation and synchronicity using deformation imaging. It has gained growing importance over the last decade, especially in human medicine as a method of evaluating myocardial function. This review aims to give an overview of the current understanding of this technique and its clinical applicability in the field of veterinary medicine with a focus on early detection of left ventricular dysfunction in dogs.

Abstract

Two-dimensional speckle-tracking echocardiography (2D–STE) is an advanced echocardiographic technique based on deformation imaging that allows comprehensive evaluation of the myocardial function. Clinical application of 2D–STE holds great potential for its ability to provide valuable information on both global and regional myocardial function and to quantify cardiac rotation and synchronicity, which are not readily possible with the conventional echocardiography. It has gained growing importance over the past decade, especially in human medicine, and its application includes assessment of myocardial function, detection of subclinical myocardial dysfunction and serving as a prognostic indicator. This review illustrates the fundamental concepts of deformation analysis and gives an overview of the current understanding and its clinical application of this technique in veterinary medicine, with a focus on early detection of left ventricular (LV) dysfunction in dogs.

Coronary Flow Velocity Reserve and Myocardial Deformation Predict Long-Term Outcomes in Heart Transplant Recipients

BACKGROUND

After heart transplantation (HTx), invasive coronary angiography is the gold standard for surveillance of cardiac allograft vasculopathy (CAV). Noninvasive CAV surveillance is desirable. The authors examined left ventricular global longitudinal strain (LVGLS) and noninvasive coronary flow velocity reserve (CFVR) related to CAV and prognosis after HTx.

METHODS

Doppler echocardiographic CFVR and LVGLS were evaluated in 98 HTx patients. All-cause mortality and major adverse cardiac events (MACE), including hospitalization for heart failure, cardiovascular death, and significant CAV progression, were recorded.

RESULTS

Median follow-up duration was 3.3 years (range: 1.7-5.4 years). Patients with low CFVR (<2.0; n = 20) showed reduced MACE-free survival (hazard ratio, 4.3; 95% CI, 2.2-8.4; P < .0001) and increased all-cause mortality (hazard ratio: 4.7; 95% CI: 2.0-11.3; P < .0001) compared with patients with high CFVR (≥2.0; n = 78). Worsened LVGLS (≥-15.5%) was also a strong independent predictor of MACE and cardiovascular and all-cause mortality. Combined low CFVR and worsened LVGLS provided incremental prognostic value, even after adjustment for CAV and time since HTx. The prevalence of low CFVR increased significantly with CAV severity, and the prevalence of combined low CFVR and/or worsened LVGLS was high in patients with moderate CAV (86%) and those with severe CAV (83%). The negative predictive value of combined high CFVR and improved LVGLS to rule out significant CAV was 94.5% (95% CI, 86.2%-98.4%), whereas the positive predictive value was 39.0% (95% CI, 25.3%-54.3%). The model had sensitivity of 84.2% (95% CI, 63.6%-95.3%) and specificity of 67.5% (95% CI, 56.6%-77.2%) for one or more abnormal parameters.

CONCLUSIONS

In HTx patients with severe CAV, a higher prevalence of low CFVR and worsened LVGLS was observed. Both measurements were strong independent predictors of MACE and all-cause mortality in HTx patients. Combined CFVR and LVGLS provided incremental prognostic value and showed an excellent ability to rule out significant CAV and may be considered as part of routine CAV surveillance of HTx patients.

Feasibility of CT-derived myocardial strain measurement in patients with advanced cardiac valve disease

To explore the feasibility of CT-derived myocardial strain measurement in patients with advanced cardiac valve disease and to compare it to strain measurements derived from transthoracic echocardiography (TTE). 43 consecutive patients with advanced cardiac valve disease and clinically indicated retrospectively gated cardiac CTs were retrospectively analyzed. The longitudinal, circumferential as well as radial systolic strain were determined in all patients utilizing a commercially available CT strain software. In 36/43 (84%) patients, CT-derived longitudinal strain was compared to speckle-tracking TTE. Pearson’s correlation coefficients as well as Bland–Altman analysis were used to compare the CT-derived strain measurements to TTE. The intra- and inter-reader-reliability of the CT-derived strain measurements were assessed by intra-class correlation coefficients (ICCs). Strain measurements were feasible in all patients. CT-derived global longitudinal strain (GLS) correlated moderately with TTE-derived GLS (r = 0.6, p < 0.001). A moderate correlation between CT-derived GLS and CT-derived left ventricular ejection fraction was found (LVEF, r = − 0.66, p = 0.036). Bland–Altman analysis showed a systematic underestimation of myocardial strain by cardiac CT compared to TTE (mean difference: − 5.8%, 95% limit of agreement between − 13.3 and 1.8%). Strain measurements showed an excellent intra- and inter-reader-reliability with an intra-reader ICC of 1.0 and an inter-reader ICC of 0.99 for GLS measurements. CT-derived myocardial strain measurements are feasible in patients with advanced cardiac valve disease. They are highly reproducible and correlate with established parameters of strain measurements. Our results encourage the implementation of CT-derived strain measurement into clinical routine.

Segmentally impaired left ventricular longitudinal strain: a new predictive diagnostic parameter for asymptomatic patients with severe aortic stenosis and preserved ejection fraction

INTRODUCTION

This study aims to investigate the correlation between severe aortic stenosis (sAS) and impairment of left ventricular global longitudinal strain (LVGLS) in particular segments, using two-dimensional speckle tracking echocardiography in patients with sAS and normal ejection fraction of left ventricle (LVEF).

METHODS

The study included 53 consecutive patients with asymptomatic sAS and preserved LVEF. The regional longitudinal systolic LV wall strain was evaluated at the area opposite of the aorta as the median strain value of the basal, middle, and apical segments of the lateral and posterior walls and was compared to the average strain value of the interventricular septum (IVS) at the same views.

RESULTS

LVGLS was decreased and was not statistically different between three- and four-chamber views (-12.5 ± 3.6 vs -11.4 ± 5.5%, p = 0.2). The average strain values of the lateral and posterior walls were statistically reduced compared to the average value of the IVS (lateral vs IVS: -7.8 ± 3.7 vs -10 ± 5.3%, p = 0.005, posterior vs IVS: -7.7 ± 4.2 vs -10.3 ± 3.8%, p < 0.0001). There was no significant difference between lateral and posterior walls (-7.8 ± 3.7 vs -7.7 ± 4.2%, p = 0.9).

CONCLUSIONS

The strain of lateral and posterior walls of left ventricle, which lay just opposite to the aortic valve seem to be more reduced compared to other walls in patients with sAS and preserved LVEF possibly due to their anatomical position. This impairment seems to be the reason of the overall LVGLS reduction. Regional strain could be used as an extra tool for the estimation of the severity of AS as well as for prognostic information in asymptomatic patients.

Weaning from ventricular assist device support after recovery from left ventricular failure with or without secondary right ventricular failure

Although complete myocardial recovery after ventricular assist device (VAD) implantation is rather seldom, systematic search for recovery is worthwhile because for recovered patients weaning from VADs is feasible and can provide survival benefits with long-term freedom from heart failure (HF) recurrence, even if a chronic cardiomyopathy was the primary cause for the drug-refractory HF necessitating left ventricular (LVAD) or biventricular support (as bridge-to-transplantation or definitive therapy) and even if recovery remains incomplete. LVAD patients explanted for myoacardial recovery compared to those transplanted from LVAD support showed similar survival rates and a significant proportion of explanted patients can achieve cardiac and physical functional capacities that are within the normal range of healthy controls. In apparently sufficiently recovered patients, a major challenge remains still the pre-explant prediction of the weaning success which is meanwhile reliably possible for experienced clinicians. In weaning candidates, the combined use of certain echocardiography and right heart catheterization parameters recorded before VAD explantation can predict post-weaning cardiac stability with good accuracy. However, in the absence of standardization or binding recommendations, the protocols for assessment of native cardiac improvement and also the weaning criteria differ widely among centers. Currently there are still only few larger studies on myocardial recovery assessment after VAD implantation. Therefore, the weaning practice relies mostly on small case series, local practice patterns, and case reports, and the existing knowledge, as well as the partially differing recommendations which are based mainly on expert opinions, need to be periodically systematised. Addressing these shortcomings, our review aims to summarize the evidence and expert opinion on the evaluation of cardiac recovery during mechanical ventricular support by paying special attention to the reliability of the methods and parameters used for assessment of myocardial recovery and the challenges met in both evaluation of recovery and weaning decision making.

Predictive Parameters of Decreased Left Ventricular Global Longitudinal Strain at 1 Month After Pediatric Heart Transplantation

Previous reports indicate that the decreased left ventricular global longitudinal strain (LVGLS) seen in the early postoperative period of pediatric heart transplant patients generally recovers over the course of 1-2 years. In this study, we investigate the predictive capacity of preoperative parameters on the LVGLS decline seen at 1 month post transplant. Forty-six transplant subjects with 2D echocardiographic images sufficient for speckle tracking echocardiography were enrolled. We excluded patients diagnosed with cardiac allograft vasculopathy or with an episode of rejection 1 month before or after their echocardiographic examinations. The mean LVGLS was significantly reduced at 1 month when compared to 1 year following transplant (- 15.5% vs. - 19.4%, respectively, p < 0.001). The predictors of LVGLS that decline at 1 month were the LV mass z-score [odds ratio (OR) 1.452; 95% confidence interval (CI) 1.007-2.095, p = 0.046], recipient age (OR 1.124; 95% CI 1.015-1.245, p = 0.025), and donor age (OR 1.081; 95% CI 1.028-1.136, p = 0.002) in the univariate logistic regression analyses. Although multivariate analysis yielded no significant predictors, higher LV mass z-scores showed a trend associated with the decline of LVGLS (p = 0.087). The donor/recipient weight ratio was associated with the LV mass z-score (R² = 0.412, p < 0.001).

Longitudinal Strain and Strain Rate for Estimating Left Ventricular Filling Pressure in Heart Transplant Recipients

Traditional parameters have limited value to estimate left ventricular filling pressure (LVFP) in orthotropic heart transplant (OHT) recipients. We hypothesized that global longitudinal strain (GLS), diastolic, and systolic strain rate (SR) would be depressed in OHT recipients with elevated LVFP and could overcome the limitations of traditional parameters. We studied consecutively OHT patients at the time of endomyocardial biopsies and retrospectively pretransplantation studies conforming to the same protocol. Comprehensive echocardiography with strain measurements was performed. Results were compared with pulmonary capillary wedge pressure (PCWP) obtained from right heart catheterization that was performed just after the echocardiography study. In all, 74 studies were performed in 50 OHT recipients. Mean PWCP was 11.8 ± 4.3 mm Hg (range: 4 to 25 mm Hg). Several parameters, but not left atrial volume index, mitral inflow velocities, annular velocities, and their ratio (E/e'), were different between studies with normal (n = 47) and elevated PCWP (n = 27). Area Under Curve for GLS (0.932*), E/e'_SR (0.849*), and systolic SR (0.848*) (*p <0.0001) were more accurate than traditional parameters for predicting PCWP>12 mm Hg. GLS, systolic SR and E/e'_SR remained accurate regardless of LV ejection fraction and allograft vasculopathy. Meanwhile, E/e' was accurate to predict PWCP in native failing hearts before transplantation. Changes in GLS and E/e'_SR tracked accurately changes in PCWP. In conclusion, traditional indices of diastolic function perform poorly in OHT recipients, whereas GLS and E/e'_SR provide reliable means of LVFP, irrespective of ejection fraction and allograft vasculopathy. These parameters also track reasonably well the changes in LVFP.

Ventricular systolic dysfunction with and without altered myocardial contractility: Clinical value of echocardiography for diagnosis and therapeutic decision-making

The inability of one of the two or both ventricles to contract normally and expel sufficient blood to meet the functional demands of the body results from a complex interplay between intrinsic abnormalities and extracardiac factors that limit ventricular pump function and is a major cause for heart failure (HF). Even if impaired myocardial contractile function was the primary cause for ventricular dysfunction, with the progression of systolic dysfunction, additionally developed diastolic dysfunction can also contribute to the severity of HF. Although at the first sight, the diagnosis of systolic HF appears quite easy because it is usually defined by reduction of the ejection fraction (EF), in reality this issue is far more complex because ventricular pumping performance depends not only on myocardial contractility, but also largely on loading conditions (preload and afterload), being also influenced by valvular function, ventricular interdependence, pericardial constraint, synchrony of ventricular contrac-tion and heart rhythm. Conventional echocardiography (ECHO) combined with new imaging techniques such as tissue Doppler and tissue tracking can detect early subclinical alteration of ventricular systolic function. However, no single ECHO parameter reveals alone the whole picture of systolic dysfunction. Multiparametric ECHO evaluation and the use of integrative approaches using ECHO-parameter combinations which include also the ventricular loading conditions appeared particularly useful especially for differentiation between primary (myocardial damage-induced) and secondary (hemodynamic overload-induced) systolic dysfunction. This review summarizes the available evidence on the usefulness and limitations of comprehensive evaluation of LV and RV systolic function by using all the currently available ECHO techniques.

Left ventricular myocardial deformation as measure of hemodynamic burden in congenital valvular aortic stenosis

BACKGROUND

Changes in 2D echocardiography (2DE) speckle tracking imaging (STI) derived left ventricular (LV) strain (S) and strain rate (SR) precedes diminution of LV ejection fraction (LVEF) in adult valvular aortic stenosis (AS). We prospectively examined whether 2DE-STI derived multidirectional LV S and SR correlate with AS severity in children using LV mass index (MI) as the principal outcome variable.

METHODS

52 children (10.4 ± 7.3 years) with isolated congenital AS were included; 13 mild (2.5 m/s < V_max < 3.0 m/s), 25 moderate (3.0 m/s < V_max < 4.0 m/s), and 14 severe (V_max > 4.0 m/s). 2DE including Doppler and STI longitudinal strain (LS), strain rate (LSR), circumferential strain (CS), and strain rate (CSR) were measured. Univariate and multivariable linear regressions identified correlations between LVMI and strain indices.

RESULTS

Three clinical and 2DE variables, and four strain indices were independently associated with LVMI. LVMI correlated positively with systolic blood pressure and aortic regurgitation, and negatively with LVEF. LVMI correlated positively with LSR (four-chamber) and CSR (basal), and negatively with segmental CS in the inferior (basal) and anteroseptal (distal) segments. LVMI showed significant inverse association with LS (P = .05), LSR (P < .001), CS (P < .005), and CSR (P < .0001), independent of AS severity.

CONCLUSIONS

Independent of clinical and 2DE findings including contemporaneous Doppler estimates of AS gradient, both longitudinal and circumferential strain indices correlate with LVMI as a measure of cumulative hemodynamic burden. This association implies subclinical LV dysfunction.

Influence of chest conformation on myocardial strain parameters in healthy subjects with mitral valve prolapse

Chest shape might affect myocardial strain parameters. However, the relationship between myocardial strain parameters and chest conformation has not been previously investigated in subjects with mitral valve prolapse (MVP). Between April 2019 and May 2020, 60 healthy subjects (50.1 ± 8.6 year/old, 46.6% females) with MVP and mild-to-moderate mitral regurgitation, and 60 controls matched by age, sex, and cardiovascular risk factors were consecutively studied. Participants underwent modified Haller index (MHI) assessment (ratio of chest transverse diameter over the distance between sternum and spine), and transthoracic echocardiography implemented with 2D-speckle tracking analysis. MHI was significantly greater in MVP group than controls (2.6 ± 0.35 vs 2.1 ± 0.23, p < 0.0001). Left ventricular (LV) ejection fraction was similar in MVP and controls (63.5 ± 3.7% vs 64.3 ± 3.9%, p = 0.25). LV regional and global longitudinal (GLS), circumferential (GCS) and radial strain (GRS) parameters and LV peak twist were all significantly lower in MVP compared to controls (all p < 0.0001). MVP subjects with a tight chest (MHI > 2.5, n = 30), and those with MHI ≤ 2.5 (n = 30) were then separately analyzed. A significant impairment in myocardial strain parameters and LV peak twist was documented in MVP subjects with MHI > 2.5, but not in those with MHI ≤ 2.5. MHI showed a strong inverse correlation with LV-GLS (r = - 0.85), GCS (r = - 0.84), GRS (r = - 0.84) and LV peak twist (r = - 0.94). In MVP subjects, impairment of myocardial strain parameters is not due to intrinsic reduction of cardiac contractility function, but it appears to be related to the degree of chest deformity.

Evaluation of Left Ventricular Myocardial Work Performance in Patients Undergoing On-Pump and Off-Pump Coronary Artery Bypass Surgery

Purpose: Benefits of off-pump coronary bypass (OPCAB) over on-pump (ONCAB) remain controversial. We aimed to evaluate the early impacts of OPCAB vs ONCAB for varying left ventricular (LV) function baselines by applying the non-invasive myocardial work (MW) analysis, which enables further insights in cardiac mechanics, contractility, and efficacy.

Methods: We retrospectively analyzed 98 patients (55 ONCAB vs 43 OPCAB). Transthoracic echocardiography (TTE) and concurrent arterial blood pressure measurements taken at rest, prior to, and early after surgery were performed. Global myocardial work index (GMWI), global constructive work (GCW), and global work efficiency (GWE), inter alia, were quantified.

Results: Preoperatively, OPCAB patients had significantly lower values than ONCAB patients in terms of GMWI (1404.33 ± 585.41 mmHg% vs 1619.07 ± 535.42 mmHg%, p = 0.039), GWE (90% (60%, 96%) vs 93% (74%, 98%), p = 0.028). After surgery, GMWI was reduced in both groups. However, a more significant GMWI impairment occurred early after ONCAB than after OPCAB (−343.14 ± 35.20 mmHg%, p <0.001 vs −224.04 ± 120.91 mmHg%, p = 0.042).

Conclusion: Despite lower preoperative LV function in OPCAB patients, GMWIs after OPCAB were superior to ONCAB, indicating better preservation of systolic LV function early after OPCAB by means of contractility compared to ONCAB. Further studies should investigate the long-term course of MW response and their clinical impact.

Non-invasive cardiac allograft rejection surveillance: reliability and clinical value for prevention of heart failure

Allograft rejection-related acute and chronic heart failure (HF) is a major cause of death in heart transplant recipients. Given the deleterious impact of late recognized acute rejection (AR) or non-recognized asymptomatic antibody-mediated rejection on short- and long-term allograft function improvement of AR surveillance and optimization of action strategies for confirmed AR can prevent AR-related allograft failure and delay the development of cardiac allograft vasculopathy, which is the major cause for HF after the first posttransplant year. Routine non-invasive monitoring of cardiac function can improve both detection and functional severity grading of AR. It can also be helpful in guiding the anti-AR therapy and timing of routine surveillance endomyocardial biopsies (EMBs). The combined use of EMBs with non-invasive technologies and methods, which allow detection of subclinical alterations in myocardial function (e.g., tissue Doppler imaging and speckle-tracking echocardiography), reveal alloimmune activation (e.g., screening of complement-activating donor-specific antibodies and circulating donor-derived cell-free DNA) and help in predicting the imminent risk of immune-mediated injury (e.g., gene expression profiling, screening of non-HLA antibodies, and circulating donor-derived cell-free DNA), can ensure the best possible surveillance and management of AR. This article gives an overview of the current knowledge about the reliability and clinical value of non-invasive cardiac allograft AR surveillance. Particular attention is focused on the potential usefulness of non-invasive tools and techniques for detection and functional grading of early and late ARs in asymptomatic patients. Overall, the review aimed to provide a theoretical and practical basis for those engaged in this particularly demanding up-to-date topic.

Global longitudinal reference ranges for fetal myocardial deformation in the second half of pregnancy

PURPOSE

To construct longitudinal fetal reference ranges for global longitudinal myocardial deformation (strain and strain rate) of the left and right ventricles in the second half of pregnancy.

METHODS

A prospective, observational, longitudinal study of 120 women with uncomplicated singleton pregnancies. The participants underwent ultrasonographic scans every 4 weeks from enrolment (18-28 weeks) until delivery. Strain and strain rate were measured at each examination using velocity vector imaging. Changes in strain and strain rate as functions of gestational age (GA) were modeled using Bayesian mixed effects models.

RESULTS

A total of 406 assessments of global longitudinal strain and strain rate were performed for 120 women. Global longitudinal strain and strain rate decreased with increasing GA in the left ventricle. There was, however, no change in strain measurements of the right ventricle over the same gestational time frame. Posterior predictive distributions were used to derive reference centiles for each week of GA.

CONCLUSION

Assessment of myocardial deformation of the fetal heart is easily performed and may be useful for quantitative assessment of heart function, particularly in fetuses at risk of cardiac dysfunction.

Heart transplantation ten-year follow-ups: Deformation differentiation comparison of myocardial performance in left ventricle and right ventricle

BACKGROUND

We try to investigate whether the values of three-dimensional principal longitudinal strain present differently between the left and right ventricles in patients with long-time follow-ups after heart transplantation (HTx).

METHODS AND RESULTS

Transthoracic echocardiography with three-dimensional speckle tracking was performed at one-, five- and ten-year follow-ups in 62 "healthy" HTx patients together with routine echocardiographic evaluation in 32 control group (CG) individuals. Longitudinal strain was applied in all subjects assessing without myocardium wall motion abnormality. Firstly, left ventricular ejection fraction preserved in HTx and had no significant difference in comparison with the controls (p > .05). 3D measurement showed obvious reduction in global (%: CG: -20.5 ± 3.5 vs. HT1y: -13.7 ± 4.6, HT5y: -14.4 ± 4.5, HT10y: -14.6 ± 4.7. p < .01) and horizontal segmental (basal, mid, apical, CG vs. HTx: all p < .01) strain values of the left compared HTx with control subjects. Secondly, tissue Doppler imaging s' velocity and tricuspid annular plane systolic excursion reduced in HTx as compared to the controls in right ventricle (p < .01). Longitudinal strain presented a more distinctive reduction in global (%: CG: -24.5 ± 4.6 vs. HT1y:-14.8 ± 7.5, HT5y: -15.5 ± 6.4, HT10y: -15.9 ± 6.8. p < .01) and horizontal segmental (basal, mid, apical, CG vs. HTx: all p < .01) average values of the right compared HTx with control subjects. Thirdly, there weren't any significant changes between one-, five- and ten-year of all the values with HTx inter-group comparison in both the left and right ventricles (p > .05). Fourthly, the global and segmental strain of the right ventricle decreased more than that of the left ventricle in all HTx groups, with the global decreased differentiation rates of 7%, 7%, 6%, respectively.

CONCLUSIONS

Compared HTx with control subjects in both ventricles, conventional evaluation showed preserved or decreased functions in the left and right separately. Myocardial function evaluating by 3D longitudinal strain reduced after HTx, but the deformation of the right ventricle reduced more than those of the left ventricle. Additionally, 3D strain values almost remained with stable decreased differentiation rates during the long-time follow-ups.

Diagnostic Value of Global Cardiac Strain in Patients With Myocarditis

BACKGROUND

Cardiac strain represents an imaging biomarker of contractile dysfunction.

PURPOSE

The purpose of this study was to investigate the diagnostic value of cardiac strain obtained by feature-tracking cardiac magnetic resonance (MR) in acute myocarditis.

MATERIALS AND METHODS

Cardiac MR examinations of 46 patients with myocarditis and preserved ejection fraction at acute phase and follow-up were analyzed along with cardiac MR of 46 healthy age- and sex-matched controls. Global circumferential strain and global radial strain were calculated for each examination, along with myocardial edema and late gadolinium enhancement, and left ventricle functional parameters, through manual contouring of the myocardium. Correlations were assessed using Spearman ρ. Wilcoxon and Mann-Whitney U test were used to assess differences between data. Receiver operating characteristics curves and reproducibility were obtained to assess the diagnostic role of strain parameters.

RESULTS

Global circumferential strain was significantly lower in controls (median, -20.4%; interquartile range [IQR], -23.4% to -18.7%) than patients in acute phase (-18.4%; IQR, -21.0% to -16.1%; P = 0.001) or at follow-up (-19.2%; IQR, -21.5% to -16.1%; P = 0.020). Global radial strain was significantly higher in controls (82.4%; IQR, 62.8%-104.9%) than in patients during the acute phase (65.8%; IQR, 52.9%-79.5%; P = 0.001). Correlations were found between global circumferential strain and global radial strain in all groups (acute, ρ = -0.580, P < 0.001; follow-up, ρ = -0.399, P = 0.006; controls, ρ = -0.609, P < 0.001), and between global circumferential strain and late gadolinium enhancement only in myocarditis patients (acute, ρ = 0.035, P = 0.024; follow-up, ρ = 0.307, P = 0.038).

CONCLUSIONS

Cardiac strain could potentially have a role in detecting acute myocarditis in low-risk acute myocarditis patients where cardiac MR is the main diagnosing technique.

Early left atrial dysfunction in idiopathic pulmonary fibrosis patients without chronic right heart failure

No data are actually available regarding the left atrial (LA) functional assessment by two-dimensional speckle tracking echocardiography (2D-STE) in early-stage idiopathic pulmonary fibrosis (IPF). The primary end-point of our study was to assess whether global LA peak strain (GLAPS), measured by 2D-STE analysis, may detect early alterations in LA function in IPF patients without right heart failure (RHF). Between September 2017 and January 2019, 50 consecutive IPF patients (73.8 ± 6.8 years, 36 males) without chronic RHF and 30 controls matched by age, sex and cardiovascular risk factors, were enrolled in an observational retrospective case-control study. All patients underwent a complete echocardiographic study implemented with 2D-STE analysis. GLAPS, left ventricular (LV) global longitudinal strain (GLS), right atrial (RA) reservoir strain (GSA+) and right ventricular (RV)-GLS were obtained in each patient. LVFP were significantly increased in IPF patients in comparison to controls (average E/e' ratio 14.4 ± 3.0 vs 9.6 ± 1.5, p < 0.0001), while LV-GLS was slightly reduced in IPF patients compared to controls (19.4 ± 3.6% vs 21.0 ± 2.2%, p = 0.03).Moreover, GLAPS was significantly impaired in IPF patients in comparison to controls (18.4 ± 3.7% vs 28.4 ± 5.6%, p < 0.0001).Finally, the two groups of patients did not show any statistically significant difference in both RA-GSA + (23.9 ± 3.7% vs 24.5 ± 4.0%, p = 0.49) and RV-GLS (- 22.6 ± 3.3% vs - 23.5 ± 3.0%, p = 0.22). Notably, LV-GLS was strongly inversely correlated both with RV/LV basal diameter ratio and TRV in IPF patients (r = - 0.87 and - 0.82, respectively) but not in controls (r = - 0.29 and - 0.27, respectively). This finding highlights a likely process of ventricular interdependence in non-advanced IPF, with consequent LV diastolic dysfunction and secondary impairment in LV-GLS and GLAPS. Early LA reservoir dysfunction in IPF patients may be secondary to LV diastolic dysfunction induced by ventricular interdependence and may develop before RV diastolic and systolic dysfunction.

Reduced Myocardial Strain Parameters in Subjects With Pectus Excavatum: Impaired Myocardial Function or Methodological Limitations Due to Chest Deformity?

Pectus excavatum (PE) may cause symptoms and alter cardiopulmonary function. Left ventricular (LV) and right ventricular (RV) function have been reported to be impaired in PE subjects. However, this issue has not been systematically investigated with respect to the degree of chest wall abnormality. We aimed to evaluate the influence of severity of chest shape abnormality on myocardial strain parameters in PE subjects. We studied 30 healthy subjects (55.8 ± 14.0 year/old, 18 males) with PE, assessed by the ratio of chest transverse diameter over the distance between sternum and spine (modified Haller index, MHI, >2.5), and 30 controls (MHI ≤2.5) matched by age, sex, and cardiovascular risk factors. Participants underwent 2-dimensional (2D) transthoracic echocardiography implemented with 2D-speckle tracking echocardiography. Right-heart and left-heart chamber dimensions, and stroke volume, were significantly reduced in PE subjects (all P< 0.0001). While LV ejection fraction, E/A, and E/e', did not significantly differ between the 2 groups, all LV and RV strain and strain rate parameters were severely reduced in subjects with PE (P < 0.0001). Importantly, in PE subjects, but not in controls, LV global longitudinal strain, LV global circumferential strain, LV global radial strain, and RV free wall systolic strain, were all linearly correlated to MHI (all P < 0.0001). In healthy subjects with PE, abnormal chest anatomy progressively impairs myocardial strain. However, this impairment is not due to subclinical myocardial dysfunction; it might reflect intraventricular dyssynchrony due to compressive phenomena, or technical limitations of strain methodology, due to chest wall abnormality.

Fragmented QRS and subclinical left ventricular dysfunction in individuals with preserved ejection fraction: A speckle-tracking echocardiographic study

INTRODUCTION

Fragmented QRS (fQRS) complex on routine 12-lead electrocardiogram (ECG) predicts adverse outcomes in patients with cardiovascular diseases. In addition, it has been found to be associated with subclinical myocardial dysfunction in chronic diseases. We sought to investigate the relationship between the presence of fQRS with the myocardial functions in individuals free from known systemic cardiovascular diseases.

METHODS

In a case-control study, we evaluated normal individuals from March 2017 to February 2018. All participants underwent a 2-dimensional transthoracic echocardiographic examination using tissue Doppler imaging (TDI) and speckle-tracking echocardiography. In addition, all participants were examined using a 12-lead surface ECG, and patients with fQRS and a group of age- and sex-matched controls without fQRS were enrolled in our study.

RESULTS

The patients' mean age was 40.3 ± 10.7 and 35.4 ± 11.2 years in fQRS-positive and fQRS-negative groups, respectively (P = .110). Patients with fQRS had significantly lower values of apical left ventricular global longitudinal strain (LV GLS) in 2-chamber (16.9 ± 2.5 vs. 20.5 ± 3.3, P < .001), 4-chamber (16.9 ± 3.4 vs. 20.1 ± 3, P = .001), LAX views (17.7 ± 2.8 vs. 20.8 ± 3.5, P = .001), and averaged LV GLS (17 ± 2.6 vs. 20.4 ± 2.7, P < .001) values compared to patients without fQRS. In a multivariate analysis, averaged LV GLS and smoking history were independent predictors for positive fQRS.

CONCLUSION

The presence of fQRS on 12-lead ECG in healthy population was associated with lower values of LV GLS compared to normal individuals without fQRS.

Short-term echocardiographic evaluation by global longitudinal strain in patients with heart failure treated with sacubitril/valsartan

AIMS

The angiotensin receptor neprilysin inhibitor (ARNI) sacubitril/valsartan reduces mortality and hospitalizations in patients with heart failure and reduced ejection fraction (HFrEF). Favourable effects on haemodynamic and functional parameters have been observed in patients with HFrEF undergoing ARNI therapy, using standard transthoracic echocardiography. Global longitudinal strain (GLS) assessment uses a semi-automatic procedure to provide a reliable and repeatable method that improves the detection of early changes of contractile function. We aimed to assess the effects of ARNI on GLS and myocardial mechanics in patients with HFrEF.

METHODS AND RESULTS

Thirty patients with New York Heart Association class II-III HFrEF were treated with ARNI and monitored using standard echocardiographic examination and GLS measurements at baseline, 3 months, and 6 months. ARNI therapy resulted in a significant reduction of ventricular volumes and a significant increase in left ventricular ejection fraction at 6 months but not 3 months by standard transthoracic echocardiography (left ventricular ejection fraction from 28 ± 8% at baseline to 34 ± 12% at 6 months, P < 0.001). Non-significant differences in the size of the left atrium, right ventricular function, and pulmonary pressures were found at 6 months. By using GLS, there was a progressive improvement of all strain parameters by 3 months. The improvement showed a progressive trend over time and maintained significance at 6 months: GLS 4ch -7.2 ± 4.8% at baseline vs. -7.5 ± 3.9% at 3 months (P = 0.025) and - 9.2 ± 5.2% at 6 months (P = 0.0001); AVG GLS -6.9 ± 4.3 at baseline vs. -7.9 ± 4.2 at 3 months (P = 0.04) and - 8.8 ± 4.4 at 6 months (P = 0.035); GLS endo 8.2 ± 4.8 at baseline vs. -9.0 ± 4.8 at 3 months (P = 0.05) and - 10.1 ± 5.1 at 6 months (P = 0.001).

CONCLUSIONS

Sacubitril/valsartan induces an early benefit on left ventricular remodelling, which is captured by myocardial strain and not by standard echocardiography. Strain method represents a practical tool to assess early and minimal variations of left ventricular systolic function.

Diagnostic value of myocardial strain using two-dimensional speckle-tracking echocardiography in acute cardiac allograft rejection: A systematic review and meta-analysis

BACKGROUND

Two-dimensional speckle-tracking echocardiography (2D STE) has been demonstrated to have certain diagnostic utility in heart transplantation (HTX) patients with acute cardiac allograft rejection (ACAR). The aim of the systematic review and meta-analysis was to evaluate the diagnostic value of common strain parameters for ACAR in HTX patients.

METHODS

After conducting a database search, we selected studies evaluating left ventricular global longitudinal strain (GLS), circumferential strain (CS), radial strain (RS), and free wall right ventricular longitudinal strain (RV FW) in rejection group vs rejection-free group.

RESULTS

After reviewing 886 publications, seven studies were finally included in the meta-analysis, representing the data of 1173 pairs of endomyocardial biopsy and echocardiographic examination. Heart transplantation patients with rejection had significantly lower GLS than rejection-free subjects (weighted mean difference -2.32 (95% CI, -3.41 to -1.23; P < .001). Heart transplantation patients with rejection had significantly lower CS than rejection-free subjects (weighted mean difference -2.49 (95% CI, -4.05 to -0.91; P = .0019). In addition, HTX patients with rejection also had significantly lower RV FW (weighted mean difference -4.90 (95% CI, -6.15 to -3.65; P < .001).

CONCLUSIONS

The meta-analysis and systematic review demonstrate that myocardial strain parameters derived from 2D STE may be useful in detecting ACAR in HTX patients. The present results provide encouraging evidence to consider the routine use of GLS, CS, and RV FW as markers of graft function involvement during ACAR.

Severe hypoglycemia exacerbates myocardial dysfunction and metabolic remodeling in diabetic mice

Although several studies have revealed that adverse cardiovascular events in diabetic patients are closely associated with severe hypoglycemia (SH), the causal relationship and related mechanisms remain unclear. This study aims to investigate whether SH promotes myocardial injury and further explores the potential mechanisms with focus on disturbances in lipid metabolism. SH promoted myocardial dysfunction and structural disorders in the diabetic mice but not in the controls. SH also enhanced the production of myocardial proinflammatory cytokines and oxidative stress. Moreover, myocardial lipid deposition developed in diabetic mice after SH, which was closely related to myocardial dysfunction and the inflammatory response. We further found that myocardial metabolic remodeling was associated with changes in PPAR-β/δ and its target molecules in diabetic mice exposed to SH. These findings demonstrate that SH exacerbates myocardial dysfunction and the inflammatory response in diabetic mice, which may be induced by myocardial metabolic remodeling via PPAR-β/δ.

Left and right ventricular function detection and myocardial deformation analysis in heart transplant patients with long-time follow-ups

OBJECTIVE

We try to investigate whether the values of longitudinal strain present differences between the left and right ventricles in long-time follow-ups after heart transplantation (HTx) with dynamic changes in function.

METHODS AND RESULTS

Follow-up transthoracic echocardiography was performed in 1- and 3-month and 1- and 5-year follow-ups in 50 "healthy" HTx patients and compared with 26 control subjects. The left ventricle with preserved ejection fraction evaluated by biplane Simpson (control group [CG] vs HT; P > .05) had an obvious reduction in global (CG: -20.49 ± 2.38 vs heart transplant 1 month [HT1m]: -13.06 ± 2.86, heart transplant 3 month [HT3m]: -13.61 ± 2.61, heart transplant 1 year [HT1y]: -13.69 ± 4.56, heart transplant 5 year [HT5y]: -14.41 ± 4.54; P < .001) and horizontal segmental (basal, mid, apical) (P < .001) together with chamber segmental (apical 4-chamber, apical 3-chamber, apical 2-chamber) (P < .001) average strain values. The right ventricle with reduced ventricular function measured by tissue Doppler imaging S' and tricuspid annular plane systolic excursion had a more distinctive reduction in global (CG: -24.53 ± 4.20 vs HT1m: -12.94 ± 5.03, HT3m: -13.68 ± 4.35, HT1y: -14.95 ± 7.50, HT5y: -15.20 ± 6.15; P < .001) with segmental lateral (P < .001) strain values. There were not any significant changes between 1- and 3-month follow-ups of all the values (P > .05). But it could be seen that values increased in 1- and 5-year follow-ups compared with the baseline of 1- and 3-month follow-ups (P < .05). The global and segmental strain of the right ventricle decreased more than that of the left ventricle in all HTx groups, and the strain values were decreased in the HTx groups compared with the CG, with the global decreased change rates being 11%, 10%, 6%, and 8%, respectively.

CONCLUSIONS

The strain values decreased after HTx and almost remained stable in the long-time follow-ups. Compared with the CG in both ventricles, they were with preserved or reduced functions. In addition, the deformation values of the right ventricle decreased more than those of the left.

The effect of varying intensities of lower limb eccentric muscle contractions on left ventricular function

Purpose

The effect of eccentric (ECC) resistance exercise (RE) on myocardial mechanics is currently unknown.

Method

This study investigated ECC RE at varying intensities on left ventricular (LV) function using LV strain (ε), wall stress and haemodynamic parameters. Twenty-four healthy male volunteers completed ECC leg extensions at 20%, 50% and 80% of their ECC maximal voluntary contraction (MVC), whilst receiving echocardiograms. Global longitudinal ɛ, strain rate (SR), longitudinal tissue velocity, heart rate (HR), blood pressure (BP), mean arterial pressure (MAP), LV wall stress and rate pressure product (RPP) were assessed at baseline and during exercise.

Results

Left ventricular global ɛ, systolic SR and wall stress remained unchanged throughout. Systolic blood pressure (sBP), MAP and RPP increased at 80% and 50% intensities compared to rest (P < 0.01). Eccentric RE increased HR and peak late diastolic SR at all intensities compared to rest (P < 0.02).

Conclusion

The findings suggest acute ECC RE may not alter main parameters of LV function, supporting future potential for wider clinical use. However, future studies must investigate the impact of multiple repetitions and training on LV function.

Impaired myocardial deformation and ventricular vascular coupling in obese adolescents with dysglycemia

Background

It is unknown that dysglycemia in obese adolescents has effects on myocardial deformation that are more pronounced when compared to obesity alone. We hypothesized that obesity associated abnormal glucose tolerance (dysglycemia) would have adverse effects on two-dimensional speckle tracking echocardiography derived longitudinal, radial and circumferential strain (LS, RS, CS) compared to age and gender lean controls. We also examined if changes in deformation would be reflected in abnormal ventricular vascular coupling indices (VVI).

Methods

In a prospective cross-sectional design 39 obese adolescents (15.9 ± 1.7 years; 101.5 ± 39 kg; female − 58%) were compared to age and gender matched lean controls (15.7 ± 1.8 yrs, 60 ± 12.8 kg). Based on results from an oral glucose tolerance test (OGTT), obese adolescents were categorized as obese normoglycemic (ONG, n = 25) or obese dysglycemic (ODG, n = 14). Left ventricular (LV) global and average LS, CS, RS and strain rate were measured. LV ejection fraction and mass index were measured and VVI approximated as ratio of arterial elasticity (Ea) and end-systolic elastance (Ees).

Results

Adolescents with ODG had significantly (P = 0.005) impaired global LS (− 20.98% ± 2.8%) compared to controls (− 23.01% ± 2.3%). A similar (P = 0.0027) reduction was observed in average LS for adolescents with ODG (18.87% ± 2.5%) compared to controls (20.49% ± 2%). Global CS was also decreased (P = 0.03) in ODG (− 23.95%) compared to ONG (− 25.80). A similar trend was observed in average CS after multivariate regression for BMI and blood pressure. CS correlated with HbA1c in both groups (P = 0.05). VVI had a negative correlation with both LS (r = − 0.4, P = 0.025) and CS rate (r = − 0.36, P = 0.04).

Conclusions

Myocardial strain and strain rate were significantly altered in obese adolescents. Unfavorable subclinical reductions in global and average CS were more pronounced in adolescents with dysglycemia compared to obese adolescents with normoglycemia and controls. These data indicate progressive worsening of subendocardial function across the spectrum of glucose tolerance. Strain rate was predictive of VVI in obese adolescents, suggesting strain rate may be a sensitive marker for cardiac remodeling in abnormal glucose homeostasis states.

Diastolic strain imaging: a new non-invasive tool to detect subclinical myocardial dysfunction in early cardiac allograft rejection

Acute cellular rejection (ACR) remains a significant contributor to increased morbidity and mortality in heart transplant recipients. Early detection of ACR by non-invasive imaging is of potential clinical benefit. This study sought to investigate the use of non-invasive early global diastolic strain rate (GDSRe) and global longitudinal strain (GLS) in the detection of biopsy proven ACR. We retrospectively analysed 31 heart transplant patients (Mean age 52 ± 14 years) with biopsy proven ACR who underwent serial transthoracic echocardiographic examination and 2D strain analysis. Traditional echocardiographic systolic and diastolic parameters and novel systolic and diastolic strain imaging were measured during (1) early rejection free period (0R); (2) pre-rejection period (pre-1R); and (3) grade 1R acute cellular rejection (1R-ACR). GDSRe was significantly reduced (p = 0.0001) during the pre-rejection period (pre-1R) (0.74/s) when compared with 0R (0.97/s). GLS was only significantly reduced during 1R-ACR (17.7%), p = 0.001 but could not detect pre-1R (19.9%). Global diastolic strain rate at isovolumic relaxation showed no significant differences between any of the rejection periods. Traditional systolic and diastolic indices showed no significant differences. In conclusion, early global diastolic strain rate is the most sensitive parameter to detect subclinical myocardial dysfunction during early periods of pre-1R prior to biopsy confirmed 1R-ACR. GDSRe is a potential new tool for non-invasive screening of early post-transplant cardiac allograft rejection.

Two-dimensional systolic speckle tracking echocardiography provides a noninvasive aid in the identification of acute pediatric heart transplant rejection

BACKGROUND

Acute rejection is an important cause of morbidity and mortality in the pediatric heart transplant (HT) population. A reliable noninvasive method for diagnosis of clinical rejection could substantially reduce these negative outcomes.

OBJECTIVE

Evaluate left ventricular (LV) global longitudinal strain (GLS), and global circumferential strain (GCS) as early noninvasive indicators of acute pediatric HT rejection.

METHODS

An 18-month prospective cohort study involving 61 patients evaluated absolute change in peak global systolic strain (GLS and GCS) from enrollment (baseline) to next planned clinical encounter (follow-up) or rejection. Acute rejection defined as a biopsy of grade ≥ 2R or treatment with enhanced immunosuppression by the transplant team, blinded to strain analysis. Two patient cohorts three months post HT without evidence of rejection at enrollment were identified. The study cohort experienced rejection. The control cohort remained free from rejection on follow-up. Two-way analysis of variance (ANOVA) models evaluated change in GLS and GCS by cohort group and time.

RESULTS

Applying exclusion criteria, 51 patients enrolled in the control cohort and 10 in the study cohort. The study cohort's mean GLS declined 33% from baseline to rejection (P < .001) and mean GCS declined 16.6% (P = .021). No significant change from baseline to follow-up was seen in the control cohort. A threshold absolute GLS value of 16.1% identified acute rejection with 100% sensitivity and 98% specificity (Likelihood Ratio, [LR] 51).

CONCLUSION

Noninvasive global longitudinal strain was sensitive and specific in the identification of acute clinical rejection in pediatric HT recipients.

Speckle Tracking Echocardiography and All-Cause and Cardiovascular Mortality Risk in Chronic Kidney Disease Patients

Background and Objectives: Patients with chronic kidney disease (CKD) exhibit a highly increased risk of cardiovascular (CV) morbidity and mortality. Subtle changes in left ventricular function can be detected by two-dimensional (2D) speckle tracking echocardiography (STE). This study investigated whether myocardial dysfunction detected by 2D STE may aid in CV and all-cause mortality risk assessment in patients with CKD stages 3 and 4. Method: A study group of 285 patients (CKD 3: 193 patients; CKD 4: 92 patients) and a healthy control group (34 participants) were included in the retrospective study. 2D STE values as well as early and late diastolic strain rates were measured in ventricular longitudinal, circumferential and radial directions. Patients’ CV and all-cause outcome was determined. Results: In the CKD group all measured longitudinal STE values and radial strain were significantly reduced compared to the control group. Cox proportional hazards regression revealed global longitudinal strain to predict CV and all-cause mortality (hazard ratio [HR] 1.15, 95% CI 1.06–1.25; p = 0.0008 and HR 1.09, 95% CI 1.04–1.14; p = 0.0003). After adjustment for sex, age, diabetes, estimated glomerular filtration rate, and preexisting CV disease, this association was maintained for CV mortality and all-cause mortality (HR 1.16, 95% CI 1.06–1.27; p = 0.0019 and HR 1.08, 95% CI 1.03–1.14; p = 0.0026, respectively). Conclusions: The present study shows that 2D STE detects reduced left ventricular myocardial function and allows the prediction of CV and all-cause mortality in patients at CKD stages 3 and 4.

Evaluation of subclinical left ventricular dysfunction in overweight people with 3D speckle-tracking echocardiography

OBJECTIVE

Obesity is associated with cardiovascular risk factors and is a major predictor of cardiovascular disease and mortality. This global burden affects myocardial function by inducing structural and functional alterations. Although subclinical left ventricular (LV) dysfunction is known in obese subjects, there is not sufficient information about overweight people. The aim of the present study was to evaluate subclinical LV dysfunction in overweight people with three-dimensional speckle-tracking echocardiography (3D-STE).

METHODS

One hundred eighteen consecutive patients between 18 and 80 years old were enrolled into the study. Patients were divided into three groups according to body mass index (BMI): normal (BMI: 18.5-24.9 kg/m2) (n=35), overweight (BMI: 25-29.9 kg/m2) (n=43), and obese (BMI ≥30 kg/m2) (n=40). 3D-STE was performed, and global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), and global area strain (GAS) were measured. 3D-STE results were compared between the groups.

RESULTS

The mean age of the patients was 60.97+-8.94 years, and 55.1% of the patient population were male. Mean GCS was -13.5, GLS was -11.9, GRS was 32.3, and GAS was -22. As BMI increased, GCS and all other strain parameters were significantly worse [p<0.001 (normal-overweight), p<0.001 (normal-obese), and p<0.001 (overweight-obese) for GCS, GLS, GRS, and GAS]. A positive linear correlation was observed between BMI and all measured strain parameters (r=0.673, p<0.001 for BMI and GCS).

CONCLUSION

3D-STE is a non-invasive parameter to detect subclinical LV dysfunction, and global strain values are significantly correlated with BMI. Subclinical LV dysfunction was detected in overweight people in addition to obese subjects.

Temporal changes in left ventricular strain with the development of rejection in paediatric heart transplant recipients

INTRODUCTION

Myocardial strain measurements are increasingly used to detect complications following heart transplantation. However, the temporal association of these changes with allograft rejection is not well defined. The aim of this study was to describe the evolution of strain measurements prior to the diagnosis of rejection in paediatric heart transplant recipients.

METHODS

All paediatric heart transplant recipients (2004-2015) with at least one episode of acute rejection were identified. Longitudinal and circumferential strain measurements were assessed at the time of rejection and retrospectively on all echocardiograms until the most recent negative biopsy. Smoothing technique (LOESS) was used to visualise the changes of each variable over time and estimate the time preceding rejection at which alterations are first detectable.

RESULTS

A total of 58 rejection episodes were included from 37 unique patients. In the presence of rejection, there were decrements from baseline in global longitudinal strain (-18.2 versus -14.1), global circumferential strain (-24.1 versus -19.6), longitudinal strain rate (-1 versus -0.8), circumferential strain rate (-1.3 versus -1.1), peak longitudinal early diastolic strain rate (1.3 versus 1), and peak circumferential early diastolic strain rate (1.5 versus 1.3) (p<0.01 for all). The earliest detectable changes occurred 45 days prior to rejection with simultaneous alterations in myocardial strain and ejection fraction.

CONCLUSIONS

Changes in graft function can be detected non-invasively prior to the diagnosis of rejection. However, changes in strain occur concurrently with a decline in ejection fraction. Strain measurements aid in the non-invasive detection of rejection, but may not facilitate earlier diagnosis compared to more traditional measures of ventricular function.