Afterload-related reference values for myocardial work indices

A novel method for the evaluation of right ventricular dysfunction in acute pulmonary embolism: Myocardial work indices

PURPOSE

The presence of right ventricular dysfunction indicates a higher risk status in patients with pulmonary embolism (PE). The RV strain evaluated by speckle-tracking echocardiography seems to be more reliable method in the evaluation of RV dysfunction as compared to standard echocardiographic measures. In this study, we aimed to determine the value of myocardial-work indices in evaluating serial changes of RV function in acute PE.

METHODS

Our study comprised 83 consecutive acute PE patients who admitted to our tertiary cardiovascular hospital. Echocardiography was performed within the first 24-hours of hospitalization, and RV and LV myocardial-work parameters were obtained along with standard echocardiographic parameters. The change in the RV/LVr detected on tomography was selected as the primary outcome measure, and its' predictors were analyzed with classical linear regression and a generalized additive model (GAM).

RESULTS

Among the LV-RV strain and myocardial work parameters, the RV global longitudinal strain (GLS) has borderline statistical significance in predicting the RV/LVr change whereas the RV global work efficiency (RV-GWE) strongly predicted RV/LVr change (p: 0.049 and <0.001, respectively).

CONCLUSION

In this study, classical linear regression and GAM analyses showed that RV-GWE seems to offer a better prediction of RV/LVr change in patients with acute PE.

Echocardiographic Myocardial Work: A Novel Method to Assess Left Ventricular Function in Patients with Coronary Artery Disease and Diabetes Mellitus

Myocardial ischemia caused by coronary artery disease (CAD) and the presence of metabolic abnormalities and microvascular impairments detected in patients with diabetes mellitus (DM) are a common cause of left ventricular (LV) dysfunction. Transthoracic echocardiography is the most-used, non-invasive imaging method for the assessment of myocardial contractility. The accurate evaluation of LV function is crucial for identifying patients who are at high risk or may have worse outcomes. Myocardial work (MW) is emerging as an alternative tool for the evaluation of LV systolic function, providing additional information on cardiac performance when compared to conventional parameters such as left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) because it incorporates deformation and load into its analysis. The potential of MW in various conditions is promising and it has gained increased attention. However, larger studies are necessary to further investigate its role and application before giving an answer to the question of whether it can have widespread implementation into clinical practice. The aim of this review is to summarize the actual knowledge of MW for the analysis of LV dysfunction caused by myocardial ischemia and hyperglycemia.

Assessing the impact of transcatheter aortic valve replacement on myocardial work indices and left ventricular diastolic function in aortic valve stenosis patients

BACKGROUND

Aortic valve stenosis (AS) is the most common valvular heart disease worldwide. When timely intervention is performed, aortic valve replacement can improve patients' quality and duration of life. Load-independent left ventricular (LV) functional assessments, such as myocardial work indices (MWIs) and LV diastolic function parameters, could help clinicians decide on the optimal timing of intervention.

AIMS

To evaluate the reliability of MWI in AS patients and the changes in MWI and LV diastolic function after transcatheter aortic valve replacement (TAVR).

METHODS

We enrolled 53 consecutive patients with severe AS undergoing TAVR admitted between March 2021 and November 2021. MWIs and LV diastolic function were assessed before and after TAVR for each patient.

RESULTS

All MWIs and LV diastolic function indices improved after TAVR. The degree of MWIs improvement was higher in patients with lower prior-TAVR MWI values, while the more severe the impairment of diastolic function, the greater the post-TAVR benefit.

CONCLUSION

The introduction of myocardial work parameters into the routine assessment of patients with AS could improve our understanding of cardiac performance and aid in identifying the optimal timing for surgical or percutaneous treatment.

Assessment of left heart dysfunction to predict doxorubicin cardiotoxicity in children with lymphoma

Objectives

The objectives of this study were to assess the changes in the left myocardial function after chemotherapy for childhood lymphoma and observe the predictive or monitor value for cancer treatment-related cardiac dysfunction (CTRCD) by speckle-tracking echocardiography.

Methods

A total of 23 children with histopathological diagnoses of lymphoma were included, with age-matched normal controls. Comparative analysis of clinical serological tests and left heart strain parameters in children with lymphoma, including left ventricular global longitudinal strain (LVGLS); global myocardial work (GMW) indices, which include global work index (GWI), global constructive work (GCW), global wasted work, and global work efficiency; and the LS of subendocardial, middle, and subepicardial layer myocardium during left ventricular systole were measured: left atrial strain of reservoir phase (LASr), left atrial strain of conduit phase (LAScd), and left atrial strain of contraction phase (LASct).

Results

One-way ANOVA showed that GLS, GWI, GCW, LASr, and LAScd were closely associated with CTRCD and multivariate logistic regression analysis showed that GLS was the most sensitive predictor for detecting patients at lofty risk of anthracycline-related cardiotoxicity. Both before and after chemotherapy, GLS in the left ventricle showed a pattern of basal segment < middle segment < apical segment and subepicardial < middle < subendocardial layer (p < 0.05), and the degree of decrease also showed a regular pattern of epicardial layer < middle layer < subendocardial layer while the difference was not significant (p > 0.05). After chemotherapy, maximum flow rate in early mitral relaxation/left atrial systolic maximum flow rate (E/A) and left atrial volume index of each group were in the normal range, and the values of LASr, LAScd, and LASct slightly increased in the second cycle and decreased significantly in the fourth cycle after chemotherapy, reaching the lowest level; LASr and LAScd were positively correlated with GLS.

Conclusion

LVGLS is a more sensitive and earlier indicator to predict CTRCD compared with conventional echocardiography-related parameters and serological markers, and GLS of each myocardial layer showed a certain regularity. Left atrial strain can be used for early monitoring of cardiotoxicity in children with lymphoma after chemotherapy.

Echocardiographic Reference Ranges of Non-Invasive Myocardial Work Indices in Newborns

Background: Myocardial work (MCW), estimated using non-invasive pressure-strain loops, is a novel approach for assessing left ventricular function. MCW offers potential advantages over left ventricular ejection fraction and global longitudinal strain (GLS). This study aimed to establish a reference range for MCW in newborns.

Methods and Results: Overall, 113 healthy newborns (mean [±SD] birth weight 3,120±378 g) were included in the study. After entering peripheral systolic and diastolic blood pressure (BP) values, global constructive work (GCW), global work index (GWI), global work efficiency (GWE), and global wasted work (GWW) were calculated using EchoPAC software (version 204). Considering a mean [±SD] GLS of −16.3±2.8%, the mean [±SD] GWI, GCW, GWW, and GWE was 698.7±147.9 mmHg%, 1,008.5±200.1 mmHg%, 58.1±28.1 mmHg%, and 93.1±2.9%, respectively. All MCW parameters in newborns were lower than those previously reported in children and adults. However, GWI and GCW were more closely correlated with BP and GLS, as in adulthood and children. Estimation of the correlation between MCW and the frame rate index revealed no significant correlations among MCW parameters.

Conclusions: Cardiac function in newborns was evaluated by assessing MCW. With the establishment of reference ranges and normative MCW data for newborns, routine clinical use and rotational mechanics are likely to become increasingly common. Future studies are needed to determine whether MCW is useful in screening for cardiac illness among newborns.

Evaluating Impact of Pulse Pressure on Indexes of Myocardial Work by Speckle-Tracking Echocardiography in Normotensive, Prehypertensive and Newly Diagnosed Hypertensive Patients

Background

The impact of pulse pressure (PP) on indexes of myocardial work (MWIs). This study aims to explore the potential association of high PP with myocardial work (MW).

Hypothesis

PP had an association with four indexes of MW in a mixed population of normotensive, prehypertensive and newly diagnosed hypertensive individuals.

Methods

The study was a single-center, cross-sectional, observational study. A total of 204 participants (66 normotensive, 35 prehypertensive and 103 newly diagnosed hypertensive individuals) were evaluated by speckle-tracking echocardiography (STE) and blood pressure measurement. According to the PP tertiles, the participants were divided into three groups: Group I (<44 mmHg, n=67), Group II (44–52 mmHg, n=68) and Group III (≥52 mmHg, n=69).

Results

In Group II and Group III, the proportion of males was higher than that in Group I (median 46 vs 30 (P=0.002)). With increasing PP, the three indexes of MW, namely, GWI, GCW and GWW, increased, and the differences among the three groups were statistically significant (P<0.001). PP was positively related to GWI, GCW and GWW and negatively correlated with GWE. After adjusting for E/e’, LVMI, LAVI and GLS, PP was still significantly correlated with the four MW indexes (both P<0.001).

Conclusion

PP had a strong association with four indexes of MW in a mixed population of normotensive, prehypertensive and newly diagnosed hypertensive individuals. The evaluation of PP and MWIs might be valuable for identifying very early diastolic impairment of the heart.