Prognostic value of myocardial deformation parameters for outcome prediction in tetralogy of Fallot.

BACKGROUND: The prognostic value of myocardial deformation parameters in adults with repaired tetralogy of Fallot (rTOF) has not been well-elucidated. We therefore aimed to explore myocardial deformation parameters for outcome prediction in adults with rTOF using cardiovascular magnetic resonance imaging (CMR). METHODS: Adults with rTOF and at least moderate pulmonary regurgitation were identified from an institutional prospective CMR registry. Left ventricular (LV) and right ventricular (RV) global strains were recorded in longitudinal (GLS), circumferential (GCS), and radial (GRS) directions. Major adverse cardiovascular events (MACE) were defined as a composite of mortality, resuscitated sudden death, sustained ventricular tachycardia (>30 seconds), or heart failure (hospital admission >24 hours). In patients with pulmonary valve replacement (PVR), pre- and post-PVR CMR studies were analyzed to assess for predictors of complete RV reverse remodeling, defined as indexed RV end-diastolic volume (RVEDVi) <110 mL/m2. Logistic regression models were used to estimate the odds ratio (OR) per unit change in absolute strain value associated with clinical outcomes and receiver operator characteristic curves were constructed with area under the curve (AUC) for select CMR variables. RESULTS: We included 307 patients (age 35 ± 13 years, 59% (180/307) male). During 6.1 years (3.3-8.8) of follow-up, PVR was performed in 142 (46%) and MACE occurred in 31 (10%). On univariate analysis, baseline biventricular ejection fraction (EF), mass, and all strain parameters were associated with MACE. After adjustment for LVEF, only LV-GLS remained independently predictive of MACE (OR 0.822 [0.693-0.976] p = 0.025). Receiver operator curves identified an absolute LV-GLS value less than 15 and LVEF less than 51% as thresholds for MACE prediction (AUC 0.759 [0.655-0.840] and 0.720 [0.608-0.810]). After adjusting for baseline RVEDVi, RV-GCS (OR 1.323 [1.094-1.600] p = 0.004), LV-GCS (OR 1.276 [1.029-1.582] p = 0.027) and LV-GRS (OR 1.101 [1.0210-1.200], p = 0.028) were independent predictors of complete remodeling post-PVR remodeling. CONCLUSION: Biventricular strain parameters predict clinical outcomes and post-PVR remodeling in rTOF. Further study will be necessary to establish the role of myocardial deformation parameters in clinical practice.

Perioperative echocardiographic strain analysis: what anesthesiologists should know.

PURPOSE: Echocardiographic strain analysis by speckle tracking allows assessment of myocardial deformation during the cardiac cycle. Its clinical applications have significantly expanded over the last two decades as a sensitive marker of myocardial dysfunction with important diagnostic and prognostic values. Strain analysis has the potential to become a routine part of the perioperative echocardiographic examination for most anesthesiologist-echocardiographers but its exact role in the perioperative setting is still being defined. CLINICAL FEATURES: This clinical report reviews the principles underlying strain analysis and describes its main clinical uses pertinent to the field of anesthesiology and perioperative medicine. Strain for assessment of left and right ventricular function as well as atrial strain is described. We also discuss the potential role of strain to aid in perioperative risk stratification, surgical patient selection in cardiac surgery, and guidance of anesthetic monitor choice and clinical decision-making in the perioperative period. CONCLUSION: Echocardiographic strain analysis is a powerful tool that allows seeing what conventional 2D imaging sometimes fails to reveal. It often provides pathophysiologic insight into various cardiac diseases at an early stage. Strain analysis is readily feasible and reproducible thanks to the use of highly automated software platforms. This technique shows promising potential to become a valuable tool in the arsenal of the anesthesiologist-echocardiographer and aid in perioperative risk-stratification and clinical decision-making.

RéSUMé: OBJECTIF: L'analyse échocardiographique de la déformation cardiaque (strain analysis) par suivi des marqueurs acoustiques (speckle-tracking) permet d'évaluer la déformation du myocarde au cours du cycle cardiaque. Ses applications cliniques se sont considérablement développées au cours des deux dernières décennies en tant que marqueur sensible du dysfonctionnement myocardique, avec des valeurs diagnostiques et pronostiques importantes. L'analyse de la déformation cardiaque a le potentiel de devenir une partie intégrante de l'examen échocardiographique périopératoire de routine pour la plupart des anesthésiologistes-échocardiographes, mais son rôle exact dans le cadre périopératoire est encore en cours de définition. CARACTéRISTIQUES CLINIQUES: Ce rapport clinique passe en revue les principes qui sous-tendent l'analyse de la déformation cardiaque et décrit ses principales utilisations cliniques pertinentes dans le domaine de l'anesthésiologie et de la médecine périopératoire. L'analyse de la déformation cardique pour l'évaluation de la fonction ventriculaire gauche et droite ainsi que de la déformation auriculaire sont décrites. Nous discutons également du rôle potentiel de l'analyse de la déformation cardiaque pour aider à la stratification du risque périopératoire, à la sélection des patients en chirurgie cardiaque, à l'orientation du choix des moniteurs anesthésiques, et à la prise de décision clinique en période périopératoire. CONCLUSION: L'analyse échocardiographique de la déformation cardiaque est un outil puissant qui permet de voir ce que l'imagerie 2D conventionnelle ne parvient parfois pas à révéler. Elle fournit souvent un aperçu physiopathologique de diverses maladies cardiaques à un stade précoce. L'analyse de la déformation cardiaque est facilement réalisable et reproductible grâce à l'utilisation de plateformes logicielles hautement automatisées. Cette technique est potentiellement prometteuse et pourrait devenir un outil précieux dans l'arsenal de l'anesthésiologiste-échocardiographe et aider à la stratification du risque périopératoire et à la prise de décision clinique.

Myocardial strain of the left ventricle by speckle tracking echocardiography: From physics to clinical practice.

Speckle tracking echocardiography (STE) is a reliable imaging technique of recognized clinical value in several settings. This method uses the motion of ultrasound backscatter speckles within echocardiographic images to derive myocardial velocities and deformation parameters, providing crucial insights on several cardiac pathological and physiological processes. Its feasibility, reproducibility, and accuracy have been widely demonstrated, being myocardial strain of the various chambers inserted in diagnostic algorithms and guidelines for various pathologies. The most important parameters are Global longitudinal strain (GLS), Left atrium (LA) reservoir strain, and Global Work Index (GWI): based on large studies the average of the lower limit of normality are -16%, 23%, and 1442 mmHg%, respectively. For GWI, it should be pointed out that myocardial work relies primarily on non-invasive measurements of blood pressure and segmental strain, both of which exhibit high variability, and thus, this variability constitutes a significant limitation of this parameter. In this review, we describe the principal aspects of the theory behind the use of myocardial strain, from cardiac mechanics to image acquisition techniques, outlining its limitation, and its principal clinical applications: in particular, GLS have a role in determine subclinical myocardial dysfunction (in cardiomyopathies, cardiotoxicity, target organ damage in ambulatory patients with arterial hypertension) and LA strain in determine the risk of AF, specifically in ambulatory patients with arterial hypertension.

Evolving Applications of Echocardiography in the Evaluation of Left Atrial and Right Ventricular Strain.

PURPOSE OF REVIEW: Speckle-tracking echocardiography (STE) can assess myocardial motion in non-LV chambers-including assessment of left atrial (LA) and right ventricular (RV) strain. This review seeks to highlight the diagnostic, prognostic, and clinical significance of these parameters in heart failure, atrial fibrillation (AF), diastolic dysfunction, pulmonary hypertension (PH), tricuspid regurgitation, and heart transplant recipients. RECENT FINDINGS: Impaired LA strain reflects worse LV diastolic function in individuals with and without HF, and this is associated with decreased exercise capacity. Initiating treatments targeting these functional aspects may enhance exercise capacity and potentially prevent heart failure (HF). Impaired LA strain also identifies patients with a high risk of AF, and this recognition may lead to preventive strategies. Impaired RV strain has significant clinical and prognostic implications across various clinical scenarios, including HF, PH, tricuspid regurgitation, or in heart transplant recipients. STE should not be limited to the assessment of deformation of the LV myocardium. The use of LA and RV strain is supported by a substantial evidence base, and these parameters should be used more widely.

The Interfield Strength Agreement of Left Ventricular Strain Measurements at 1.5 T and 3 T Using Cardiac MRI Feature Tracking.

BACKGROUND: Left ventricular (LV) strain measurements can be derived using cardiac MRI from routinely acquired balanced steady-state free precession (bSSFP) cine images. PURPOSE: To compare the interfield strength agreement of global systolic strain, peak strain rates and artificial intelligence (AI) landmark-based global longitudinal shortening at 1.5 T and 3 T. STUDY TYPE: Prospective. SUBJECTS: A total of 22 healthy individuals (mean age 36 ± 12 years; 45% male) completed two cardiac MRI scans at 1.5 T and 3 T in a randomized order within 30 minutes. FIELD STRENGTH/SEQUENCE: bSSFP cine images at 1.5 T and 3 T. ASSESSMENT: Two software packages, Tissue Tracking (cvi42, Circle Cardiovascular Imaging) and QStrain (Medis Suite, Medis Medical Imaging Systems), were used to derive LV global systolic strain in the longitudinal, circumferential and radial directions and peak (systolic, early diastolic, and late diastolic) strain rates. Global longitudinal shortening and mitral annular plane systolic excursion (MAPSE) were measured using an AI deep neural network model. STATISTICAL TESTS: Comparisons between field strengths were performed using Wilcoxon signed-rank test (P value < 0.05 considered statistically significant). Agreement was determined using intraclass correlation coefficients (ICCs) and Bland-Altman plots. RESULTS: Minimal bias was seen in all strain and strain rate measurements between field strengths. Using Tissue Tracking, strain and strain rate values derived from long-axis images showed poor to fair agreement (ICC range 0.39-0.71), whereas global longitudinal shortening and MAPSE showed good agreement (ICC = 0.81 and 0.80, respectively). Measures derived from short-axis images showed good to excellent agreement (ICC range 0.78-0.91). Similar results for the agreement of strain and strain rate measurements were observed with QStrain. CONCLUSION: The interfield strength agreement of short-axis derived LV strain and strain rate measurements at 1.5 T and 3 T was better than those derived from long-axis images; however, the agreement of global longitudinal shortening and MAPSE was good. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Speckle tracking echocardiography and ß-thalassemia major. A systematic review.

Heart disease is among the primary causes of morbidity and mortality in ß-thalassemia major (ß-TM). Conventional echocardiography has failed to identify myocardial dysfunction at an early stage among these patients, thus speckle tracking echocardiography (STE) has been lately used. The objectives of this review were to 1) identify all published studies having evaluated myocardial strain among ß-TM patients, 2) gather their results, 3) compare their findings and 4) propose recommendations based on these data. Literature search was conducted in PubMed, SCOPUS and Cohrane Library. Data regarding left ventricular global longitudinal (LV-GLS), circumferential (LV-GCS) and radial strain (LV-GRS), right ventricular longitudinal strain (RV-GLS), left and right atrial strain were extracted. Thirty-five studies (34 original articles and 1 meta-analysis) have met the inclusion criteria. LV-GLS has been reported being worse in patients compared to controls in 13 of 21 studies, LV-GCS in 7 of 11 studies, LV-GRS in 6 of 7 studies, RV-GLS in 2 of 3 studies and left atrial strain in all case-control studies. Myocardial iron overload (MIO) patient subgroups had worse LV-GLS in 6 of 15 studies, LV-GCS in 2 of 7 studies and LV-GRS in none of 7 studies. A small number of studies suggest left atrial strain correlation with electrical atrial ectopy and atrial fibrillation. It is suggested that STE should be applied supplementary to conventional echocardiography for early identification of myocardial dysfunction among ß-TM patients. Potential myocardial strain utilities could be screening for myocardial iron overload, left ventricular diastolic dysfunction and atrial fibrillation.

Incremental prognostic value of myocardial strain over ventricular volume in patients with repaired tetralogy of Fallot.

OBJECTIVES: The relative incremental predictive value of myocardial deformation over ventricular volume for future adverse events in patients with repaired tetralogy of Fallot (rTOF) remains unknown. We aimed to determine the incremental prognostic value of myocardial deformation over ventricular volume to predict adverse events in patients with rToF. METHODS: We retrospectively included patients with rTOF who completed cardiac magnetic resonance (CMR) and follow-up in our hospital from January 2014 to October 2020, and stratified according to the presence or absence of adverse events during follow-up. The strain parameters of the right ventricular (RV) and left ventricular (LV) were obtained from CMR-derived feature tracking. Multivariable Cox proportional hazard models and net reclassification improvement analysis were used to analyze the prognostic information of biventricular strain and volume parameters in rTOF patients. RESULTS: Among 98 patients with rTOF, 54 (55.1%) experienced primary and/or secondary events during a median follow-up period of 27.0 months. Univariable analysis indicated that RV volume and strain were significantly associated with both primary events and all adverse events (all p < .01). Multivariable Cox regression and net reclassification improvement analyses achieved incremental global χ2 (all p < .001), C index (all p < .001), and overall correct reclassification by sequentially adding CMR-derived RV volume, RV strain and LV strain parameters to preexisting clinical factors in adverse events model analyses. CONCLUSIONS: RV and LV myocardial deformation provided incremental prognostic information and significant improvement for risk stratification over RV size and clinical variables and therefore can be combined to further enhance prognostication. KEY POINTS: • RV volume and strain were significantly associated with both primary events and all adverse events, whereas LV volume and strain were associated with primary events. • Ventricular myocardial deformation is a strong predictor of adverse outcomes of patients with repaired tetralogy of Fallot, providing increased prognostic information and significantly improved risk stratification over ventricular size.

Evaluation of the left ventricular systolic function and myocardial deformation by real-time three-dimensional (four-dimensional) and speckle-tracking echocardiography in children with type 1 diabetes mellitus.

AIM: This study aimed to evaluate the role of real-time three-dimensional (known as four-dimensional) echocardiography and three-dimensional speckle-tracking echocardiography for the early detection of left ventricular systolic dysfunction in asymptomatic children with type 1 diabetes mellitus. MATERIALS AND METHOD: This cross-sectional study included 38 patients (mean age 15.4 ± 2.9, 42.1% male) and 38 age, gender, and body measurements matched healthy children. Each patient underwent an interview about medical history, a detailed clinical examination, blood laboratory tests, conventional echocardiography, and tissue Doppler imaging. Left ventricular ejection fraction; global longitudinal, circumferential, radial strain; twist; and torsion were measured by real-time three-dimensional and speckle-tracking echocardiography. RESULTS: Conventional echocardiography and tissue Doppler imaging showed normal left ventricular systolic function in the patients. Although left ventricular ejection fraction (61.6 ± 1.4%, 61.8 ± 1.1%, p = 0.386), global longitudinal [-26.6 (-27.7 to -26.1)%, -26.2 (-27.7 to -24.9)%, p = 0.224], and radial strain [44.4 (42.4-45.9)%, 43.9 (41-46.1)%, p = 0.513] were similar to the controls, circumferential strain (-27.3 ± 1.3%, -28.0 ± 1.6%, p = 0.048) and twist (9.5 ± 2.3°, 11.4 ± 3.0°, p = 0.003) were decreased in the patients compared with controls. CONCLUSION: We found that even in children with asymptomatic type 1 diabetes mellitus with normal left ventricular ejection fraction, circumferential function was impaired and rotation pattern was changed. This novel echocardiographic method might be an important tool for detecting left ventricular systolic dysfunction in type 1 diabetes mellitus children before it becomes overt on conventional echocardiography and tissue Doppler imaging.

Evaluation of left ventricular function and myocardial deformation in children with beta-thalassemia major by real-time three-dimensional (four-dimensional) and speckle tracking echocardiography.

AIM: This study aimed to evaluate the role of real-time three-dimensional (four-dimensional) and speckle tracking echocardiography for early detection of left ventricular systolic dysfunction and also for the relationship between myocardial deformation parameters and myocardial iron load which is measured by cardiac magnetic resonance relaxation time T2* values in asymptomatic children with beta-thalassemia major. MATERIAL AND METHODS: This multicenter cross-sectional study included 40 patients (mean age 15.4 ± 2.9, 42.1% male) and 40 healthy children whose age, gender, and body mass index-matched with patients. Each participant underwent conventional echocardiography and tissue Doppler imaging. Left ventricular ejection fraction; global longitudinal, circumferential, radial strains; twist; and torsion were measured by real-time three-dimensional and speckle tracking echocardiography. Cardiac magnetic resonance imaging T2* was measured in patients. RESULTS: Left ventricular global longitudinal, circumferential, and radial strains were decreased despite preserved global ventricular function in patients compared to healthy children (p = p = .029, p = p < .001, p = .003, respectively). There were no statistically significant differences between patients with T2* ≥ 20 ms and patients with T2* < 20 ms for all echocardiographic parameters. Also, there were no significant correlations between all echocardiographic parameters and T2* values in all patients, those with T2* ≥ 20 ms, and T2* < 20 ms. CONCLUSION: We found that even in asymptomatic children with beta-thalassemia major, left ventricular longitudinal, circumferential and, radial functions were impaired by real-time three-dimensional (four-dimensional) and speckle tracking echocardiography. This novel echocardiographic method might be an important tool for detecting subclinical left ventricular systolic dysfunction irrespective of T2* values.

The Association of Pulmonary Flow Characteristics With Cardiac Function in Tricuspid Valve Malformation Fetuses: Study With Two-Dimensional Speckle Tracking Echocardiography.

OBJECTIVES: To explore the relationship between cardiac function and pulmonary flow characteristics in tricuspid valve malformation (TVM) fetuses by conventional and speckle tracking echocardiography. METHODS: Eighty-eight TVM fetuses were retrospectively included and compared with 80 normal controls. TVM fetuses in each trimester were divided into two subgroups according to pulmonary flow characteristics: those with normal pulmonary flow (TVM-N) and those with reduced or absent pulmonary flow (TVM-R/A). Cardiac measurements, Celermajer index, and Simpson-Andrews-Sharland (SAS) score were obtained. Speckle tracking echocardiography was used to compute ventricular deformation parameters. RESULTS: TVM fetuses demonstrated significantly lower global longitudinal strain (GLS) and strain rate for both ventricles than controls (all P < .05). When compared with TVM-N, left ventricular (LV) ejection fraction, LV fractional area change, right ventricular (RV) fractional area change, LVGLS, and RVGLS were significantly reduced (all P < .05), while the RV diameter Z-score, RV/LV diameter, SAS score, and Celermajer index were obviously increased in TVM-R/A in both trimesters (all P < .05). Both LVGLS and RVGLS correlated with cardiothoracic circumference ratio, RV diameter Z-score, RV/LV diameter, Celermajer index, and SAS score (all P < .01). There was a slow decline for LVGLS and RVGLS in TVM-N fetuses throughout the gestation. Conversely, these two parameters worsened rapidly in TVM-R/A group. CONCLUSIONS: TVM fetuses present biventricular dysfunction by deformation analysis in the second and third trimester of pregnancy. TVM fetuses with reduced or absent pulmonary flow exhibit significantly greater impairment and more rapid deterioration of cardiac function, which may contribute to poor outcomes.

Echocardiographic Differentiation of Pericardial Constriction and Left Ventricular Restriction.

PURPOSE OF REVIEW: Overlapping hemodynamics in constrictive pericarditis (CP) and restrictive cardiomyopathy (RCM) often pose difficulties in establishing accurate diagnosis. Echocardiography is the first-line imaging modality used for this purpose, but no single echocardiographic parameter is sufficiently robust for distinguishing between the two conditions. The newer developments may improve the diagnostic accuracy of echocardiography in this setting. RECENT FINDINGS: Recent studies have validated multiparametric algorithms, based on conventional echocardiographic parameters, which enable high sensitivity and specificity for distinguishing between CP and RCM. In addition, myocardial deformation analysis using speckle-tracking echocardiography has revealed distinct pattern of abnormalities in the two conditions. CP is characterized by impaired left ventricular apical rotation with relatively preserved longitudinal strain, esp. of ventricular and atrial septum. In contrast, RCM results in global and marked impairment of left ventricular longitudinal strain with initially preserved circumferential mechanics. Combining multiple echocardiographic parameters into step-wise algorithms and incorporation of myocardial deformation analysis help improve the diagnostic accuracy of echocardiography for distinguishing between CP and RCM. The use of machine-learning may allow easy integration of a wide range of echocardiographic and clinical parameters to permit accurate, automated diagnosis, with less dependence on the user expertise.

Comparison of Strain-Encoding and Feature-Tracking Derived Myocardial Deformation Assessment of Left Ventricular Function in a Pediatric and Adult Congenital Heart Disease Cohort.

BACKGROUND: Cardiac magnetic resonance (CMR) strain can be assessed with feature-tracking (FT), which utilizes a post-processing algorithm to quantify myocardial deformation on routine cine images, and strain-encoding magnetic resonance imaging (SENC), which uses parallel magnetization tags combined with out-of-plane phase-encoding gradients to quantify deformation. Assessing agreement is critical to determine whether results can be translated between methods. We compared SENC to FT in the assessment of left ventricle (LV) global longitudinal strain (GLS) and global circumferential strain (GCS) in a cohort of pediatric and adult congenital heart disease (ACHD) patients. METHODS: Pediatric subjects and ACHD patients underwent CMR on 1.5 T Siemens scanners, including balanced steady-state-free precession (bSSFP) cine imaging and SENC acquisitions in apical two and four chamber, left ventricular outflow tract, and short axis views. bSSFP cine imaging FT analysis was completed with Medis QStrain. Myocardial Solutions MyoStrain was used to analyze SENC. Correlation was assessed by Spearman's rank correlation coefficient. Agreement between techniques was assessed with concordance correlation coefficient (CCC) and Bland-Altman. RESULTS: The cohort included 134 patients, 75 with congenital heart disease (56%). The median age was 16.3 years (IQR 13.7, 19.5). Median LV ejection fraction was 57% (IQR 54.4, 61.6). SENC and FT were in poor agreement for GLS (Spearman's ρ = 0.58, p < 0.001; CCC 0.24) and GCS (Spearman's ρ = 0.29, p < 0.001; CCC 0.03). CONCLUSION: There was poor agreement between SENC and FT derived GLS and GCS in a cohort of pediatric and ACHD patients, suggesting that SENC and FT cannot be used interchangeably.

Evaluation of ventricular function and myocardial deformation in children with repaired tetralogy of Fallot by real-time three-dimensional (four-dimensional) echocardiography.

AIM: The left and right ventricular dysfunction are important clinical course indicators in patients with repaired tetralogy of Fallot. This study aimed to evaluate ventricular volumes, functions, and myocardial deformation in children with repaired tetralogy of Fallot by real-time three-dimensional (four-dimensional) echocardiography and compared with healthy children. It also aimed to investigate the relationships between ventricular volumes, functions, and myocardial deformation parameters in the patients. MATERIALS AND METHODS: In this cross-sectional study, 35 patients (mean age 15.1 ± 2.8 years, 54% male) and 35 healthy controls of similar age, gender, and body measurements underwent echocardiography. End-diastolic volume index, end-systolic volume index, and ejection fractions of both ventricles; global longitudinal, circumferential, radial strain, twist, and torsion of the left ventricle; the longitudinal strain of the right ventricle free wall and septum were measured. RESULTS: Left ventricular ejection fraction, global circumferential and radial strain, twist and torsion were significantly lower in patients compared with controls. Left ventricular ejection fraction correlated with global circumferential (r = -0.446, p < 0.001) and radial strain (r = -0.433, p < 0.001) in the patients. Right ventricular volumes were significantly higher, and ejection fraction was significantly lower in patients compared with controls. All right ventricular parameters correlated with each other in the patients. CONCLUSION: Left ventricular contraction pattern was changed, circumferential and radial fibres were most affected in the patients. Right ventricular dilatation and dysfunction were detected, and right ventricular ejection fraction correlated well with strain measurements of the right ventricle.

Multimodality imaging for the management of patients with primary mitral regurgitation.

Advanced cardiac imaging (ACI), including myocardial deformation imaging, 3D echocardiography and cardiac magnetic resonance, overcomes the limitations of conventional echocardiography in the assessment of patients with primary mitral regurgitation (MR). They enable a more precise MR quantification and reveal early changes before advanced and irreversible remodeling with depressed heart function occurs. ACI permits a thorough analysis of mitral valvular anatomy and MR mechanisms (important for planning and guiding percutaneous and surgical procedures) and helps to identify structural and functional changes coupled with a high arrhythmogenic potential, especially the occurrence of atrial fibrillation and heart failure development. The key question is how the data provided by ACI can improve the current management of primary MR.

Myocardial Deformation Assessed by MR Feature Tracking in Groups of Patients With Ischemic Heart Disease.

BACKGROUND: Global myocardial strain assessments have been shown to provide useful measures of contractility in many diseases, but whether feature tracking (FT)-derived strain at rest can differentiate ischemic myocardium from infarcted and remote myocardium in patients with coronary artery disease (CAD) remains unclear. PURPOSE: To evaluate the performance of magnetic resonance imaging FT-derived strain in the detection of regional myocardial deformation in ischemic, infarcted, and apparent normal myocardium in CAD. STUDY TYPE: Retrospective POPULATION: A total of 109 patients with CAD. FIELD STRENGTH/SEQUENCES: Steady-state free-precession rest cine, T1-weighted saturation-recovery fast gradient echo stress/rest perfusion, and two-dimensional phase-sensitive inversion recovery breath-hold late gadolinium enhancement (LGE) tests were performed at 3.0 T. ASSESSMENT: Based on perfusion and LGE images, left ventricular (LV) myocardial segments of CAD patients were categorized into ischemic, infarcted, and negative groups. The FT longitudinal (LS) and circumferential strain (CS) of normal subjects and the three CAD groups were calculated. Z-scores of each segment of CAD patients were calculated. STATISTIC TESTS: χ2 testing, analysis of variance (ANOVA), and Kruskal-Wallis tests. Z-scores were used to compare the strain between CAD groups. RESULTS: There were significant differences in global LS (GLS) and CS (GCS) between healthy controls (GLS: -19.0% ± 1.4%, GCS, -20.9% ± 1.8%), ischemia (GLS: -17.4% ± 2.1%, GCS, -19.6% ± 1.9%), infarction (GLS: -16.4% ± 1.9%, GCS, -17.8% ± 1.9%), and negative patients (GLS: -17.7% ± 1.4%, GCS, -20.9% ± 2.4%) (all P < 0.05). There were significant differences in regional LS and CS between ischemic (LS, -16.1% ± 5.0%, CS, -18.7% ± 5.0%), infarcted (LS, -14.8% ± 5.2%, CS, -15.3% ± 4.8%), and negative segments (LS, -17.6% ± 5.2%, CS, -19.8% ± 4.8%) (all P < 0.05). The differences in the z-scores of regional LS and CS between the ischemic, infarcted, and negative segments were also significant (all P < 0.05). DATA CONCLUSION: FT-derived rest strain indices of the LV myocardium of CAD patients were higher compared to healthy controls and varied between ischemic, infarcted, and negative segments. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 5.

Defining the optimal temporal and spatial resolution for cardiovascular magnetic resonance imaging feature tracking.

BACKGROUND: Myocardial deformation analyses using cardiovascular magnetic resonance (CMR) feature tracking (CMR-FT) have incremental value in the assessment of cardiac function beyond volumetric analyses. Since guidelines do not recommend specific imaging parameters, we aimed to define optimal spatial and temporal resolutions for CMR cine images to enable reliable post-processing. METHODS: Intra- and inter-observer reproducibility was assessed in 12 healthy subjects and 9 heart failure (HF) patients. Cine images were acquired with different temporal (20, 30, 40 and 50 frames/cardiac cycle) and spatial resolutions (high in-plane 1.5 × 1.5 mm through-plane 5 mm, standard 1.8 × 1.8 x 8mm and low 3.0 × 3.0 x 10mm). CMR-FT comprised left ventricular (LV) global and segmental longitudinal/circumferential strain (GLS/GCS) and associated systolic strain rates (SR), and right ventricular (RV) GLS. RESULTS: Temporal but not spatial resolution did impact absolute strain and SR. Maximum absolute changes between lowest and highest temporal resolution were as follows: 1.8% and 0.3%/s for LV GLS and SR, 2.5% and 0.6%/s for GCS and SR as well as 1.4% for RV GLS. Changes of strain values occurred comparing 20 and 30 frames/cardiac cycle including LV and RV GLS and GCS (p < 0.001-0.046). In contrast, SR values (LV GLS/GCS SR) changed significantly comparing all successive temporal resolutions (p < 0.001-0.013). LV strain and SR reproducibility was not affected by either temporal or spatial resolution, whilst RV strain variability decreased with augmentation of temporal resolution. CONCLUSION: Temporal but not spatial resolution significantly affects strain and SR in CMR-FT deformation analyses. Strain analyses require lower temporal resolution and 30 frames/cardiac cycle offer consistent strain assessments, whilst SR measurements gain from further increases in temporal resolution.

Right-left ventricular shape variations in tetralogy of Fallot: associations with pulmonary regurgitation.

BACKGROUND: Relationships between right ventricular (RV) and left ventricular (LV) shape and function may be useful in determining optimal timing for pulmonary valve replacement in patients with repaired tetralogy of Fallot (rTOF). However, these are multivariate and difficult to quantify. We aimed to quantify variations in biventricular shape associated with pulmonary regurgitant volume (PRV) in rTOF using a biventricular atlas. METHODS: In this cross-sectional retrospective study, a biventricular shape model was customized to cardiovascular magnetic resonance (CMR) images from 88 rTOF patients (median age 16, inter-quartile range 11.8-24.3 years). Morphometric scores quantifying biventricular shape at end-diastole and end-systole were computed using principal component analysis. Multivariate linear regression was used to quantify biventricular shape associations with PRV, corrected for age, sex, height, and weight. Regional associations were confirmed by univariate correlations with distances and angles computed from the models, as well as global systolic strains computed from changes in arc length from end-diastole to end-systole. RESULTS: PRV was significantly associated with 5 biventricular morphometric scores, independent of covariates, and accounted for 12.3% of total shape variation (p < 0.05). Increasing PRV was associated with RV dilation and basal bulging, in conjunction with decreased LV septal-lateral dimension (LV flattening) and systolic septal motion towards the RV (all p < 0.05). Increased global RV radial, longitudinal, circumferential and LV radial systolic strains were significantly associated with increased PRV (all p < 0.05). CONCLUSION: A biventricular atlas of rTOF patients quantified multivariate relationships between left-right ventricular morphometry and wall motion with pulmonary regurgitation. Regional RV dilation, LV reduction, LV septal-lateral flattening and increased RV strain were all associated with increased pulmonary regurgitant volume. Morphometric scores provide simple metrics linking mechanisms for structural and functional alteration with important clinical indices.

Assessment of atrial function by myocardial deformation techniques in hypertrophic cardiomyopathy.

BACKGROUND: Diastolic dysfunction in hypertrophic cardiomyopathy (HCM) is common, but its assessment is difficult using conventional echocardiography. AIMS: To assess left atrial (LA) function in HCM by longitudinal strain and determine its role in understanding of symptoms. METHODS: We studied 144 patients divided into 3 age- and sex-matched groups: 48 consecutive patients with HCM, 48 control subjects, and 48 athlete subjects. We assessed LA function by conventional echocardiographic parameters and by longitudinal atrial strain (early-diastolic left atrial strain during reservoir phase [LASr]; end-diastolic left atrial strain during conduit phase; end-systolic peak of the left atrial strain during contraction phase). RESULTS: NYHA classification was as follows in HCM group: I in 46%, II in 31%, III in 19%, and IV in 4%. Conventional echocardiographic parameters of diastolic function were depressed in the HCM group as compared to the control and athlete groups, but not related to symptoms. All longitudinal atrial strain parameters were significantly reduced in HCM group as compared to two groups (P < .0001). LASr was significantly correlated to peak VO2 (r = 0.44, P = .01) and was the best parameter for detecting symptomatic patients presenting with HCM, with a cutoff value of 15%: Sensitivity was 71%, specificity was 79%, PPV was 77%, and NPV was 73%. CONCLUSION: Assessment of LA function in HCM is feasible using longitudinal strain, and this technique is more reliable than conventional echocardiographic parameters for the understanding of determinants of symptoms.

Risk stratification for sudden cardiac death in patients with heart failure : Emerging role of imaging parameters.

BACKGROUND: Heart failure with reduced ejection fraction is a common condition that has a poor prognosis. Accurate selection of patients with ischemic heart disease and idiopathic dilated cardiomyopathy, who are at risk of sudden cardiac death (SCD), remains a challenge. In these cases, current indications for implantable cardioverter-defibrillators (ICD) rely almost entirely on left ventricular ejection fraction. However, this parameter is insufficient. Recently, noninvasive imaging has provided insight into the mechanism underlying SCD using myocardial deformation on echocardiography and magnetic resonance imaging. The aim of this review article was to underline the emerging role of these novel parameters in identifying high-risk patients. METHODS: A literature search was carried out for reports published with the following terms: "sudden cardiac death," "heart failure," "noninvasive imaging," "echocardiography," "deformation," "magnetic resonance imaging," and "ventricular arrhythmia." The search was restricted to reports published in English. RESULTS: The findings of this analysis suggest that cardiac magnetic resonance imaging and strain assessment by echocardiography, particularly longitudinal strain, can be promising techniques for cardiovascular risk stratification in patients with heart failure. CONCLUSION: In future, risk stratification of arrhythmia and patient selection for ICD placement may rely on a multiparametric approach using combinations of imaging modalities in addition to left ventricular ejection fraction.

Quantification of Myocardial Deformation Applying CMR-Feature-Tracking-All About the Left Ventricle?

PURPOSE OF REVIEW: Cardiac magnetic resonance-feature-tracking (CMR-FT)-based deformation analyses are key tools of cardiovascular imaging and applications in heart failure (HF) diagnostics are expanding. In this review, we outline the current range of application with diagnostic and prognostic implications and provide perspectives on future trends of this technique. RECENT FINDINGS: By applying CMR-FT in different cardiovascular diseases, increasing evidence proves CMR-FT-derived parameters as powerful diagnostic and prognostic imaging biomarkers within the HF continuum partly outperforming traditional clinical values like left ventricular ejection fraction. Importantly, HF diagnostics and deformation analyses by CMR-FT are feasible far beyond sole left ventricular performance evaluation underlining the holistic nature and accuracy of this imaging approach. As an established and continuously evolving technique with strong prognostic implications, CMR-FT deformation analyses enable comprehensive cardiac performance quantification of all cardiac chambers.