Non-invasive Pressure-strain Loop Research Articles

Noninvasive pressure-strain loop quantitative assessment of left ventricular function in anemic preterm infants with different modes of respiratory support

To investigate noninvasive pressure-strain loop (PSL) combined with two-dimensional speck tracking imaging and left ventricular pressure measurement in the evaluation of cardiac function changes in anemia of prematurity (AOP) with different modes of respiratory support, and to explore its value in detecting subclinical myocardial injury in preterm infants. This retrospective study included 79 preterm infants with anemia, according to different modes of respiratory support, who were divided into invasive respiratory support group (39 cases) and noninvasive respiratory support group (40 cases). A control group of 40 nonanemic preterm infants with matched age, sex, and gestational age were also included. Complete echocardiography was performed for each included infant. There are PSL parameters that used to evaluate cardiac function, including global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE) among the three groups were compared. Compared with the control group, the value of GWI, GCW, and GWE were significantly lower and GWW was higher in the AOP groups (P < 0.05), and GWI, GCW and GWE were much significantly lower in the invasive respiratory support group than in the noninvasive respiratory support group (P < 0.05). There was no significant difference in GLS among the three groups (P > 0.05). Noninvasive PSL analysis can quantitatively assess myocardial work in AOP with different respiratory support, which is more sensitive than other conventional echocardiographic indices. This technique may provide a new method for monitoring subclinical myocardial injury with AOP.

Quantitative assessment of left ventricular myocardial work in patients with different types of atrial fibrillation by non-invasive pressure-strain loop technique.

This study aimed to analyze myocardial work in patients with atrial fibrillation (AF) using a noninvasive pressure strain loop (PSL) technique to provide a basis for the quantitative assessment of left ventricular (LV) systolic function. LV myocardial work of 107 AF patients (56 with paroxysmal atrial fibrillation and 51 with persistent atrial fibrillation) and 55 healthy individuals were assessed by the noninvasive PSL and then compared. Global longitudinal strain (GLS) in absolute values, global work index (GWI), global constructive work (GCW), and global work efficiency (GWE) were significantly lower in the AF group than control group, whereas peak strain dispersion (PSD) and global wasted work (GWW) were significantly higher (P<.05). Further subdivision according to the AF type revealed that, compared with the controls, GLS in absolute values and GWE decreased significantly; PSD and GWW increased significantly in the paroxysmal AF group (P<.05). Nevertheless, GWI and GCW were not significantly different between paroxysmal AF and control groups (P>.05). Compared to paroxysmal AF, persistent AF induced a further decrease in absolute GLS and GWE and a further increase in GWW (P<.05), but PSD did not increase further (P>.05). Multiple linear regression analysis showed that GWI and GCW were independently associated with systolic blood pressure. GWW was associated with types of AF and left atrial volume index (LAVI). GWE was correlated with age, types of AF, disease duration, and LAVI. Receiver operating characteristic curve analysis showed that the area under the curve predicting myocardial injury was higher for GWE and GWW than for GLS (area under the curve: .880, .846, and .821, respectively). Non-invasive PSL can quantitatively assess LV systolic function in patients with different kinds of AF and detect early subclinical myocardial injury in patients with paroxysmal AF. GWE and GWW outperform GLS and LV ejection fraction when assessing myocardial injury. Systolic blood pressure, type of AF, LVAI, disease duration, and age may be associated with myocardial injury in patients with AF.

Myocardial work across different etiologies of right ventricular dysfunction and healthy controls.

Evaluating right ventricular (RV) function remains a challenge. Recently, novel echocardiographic assessment of RV myocardial work (RVMW) by non-invasive pressure-strain loops was proposed. This enables evaluation of right ventriculoarterial coupling and quantifies RV dyssynchrony and post-systolic shortening. We aimed to assess RVMW in patients with different etiologies of RV dysfunction and healthy controls. We investigated healthy controls (n=17), patients with severe functional tricuspid regurgitation (FTR; n=22), and patients with precapillary pulmonary hypertension (PCPH; n=20). Echocardiography and right heart catheterization were performed to assess 1) RV global constructive work (RVGCW; work needed for systolic myocardial shortening and isovolumic relaxation), 2) RV global wasted work (RVGWW; myocardial shortening following pulmonic valve closure), and 3) RV global work efficiency (RVGWE; describes the relation between RV constructive and wasted work). RVGCW correlated with invasive RV stroke work index (r=0.66, P<0.001) and increased in tandem with higher afterload, i.e., was low in healthy controls (454±73 mmHg%), moderate in patients with FTR (687±203 mmHg%), and highest among patients with PCPH (881±255 mmHg%). RVGWE was lower and RVGWW was higher in patients with FTR (86±8% and 91 mmHg% [53-140]) or PCPH (86±10% and 110 mmHg% [66-159]) as compared with healthy controls (96±3% and 10 mmHg%). RVMW by echocardiography provides a promising index of RV function to discriminate between patients with RV volume or pressure overload. The prognostic value of this measure needs to be settled in future studies.

Evaluation of subclinical left ventricular systolic dysfunction in obese patients by global myocardial work

ObjectiveTo evaluate subclinical LV systolic dysfunction in obese patients by global myocardial work (MW).MethodsA total of 589 obese patients and 100 normal controls were enrolled in the study. The global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work (GWW) and global work efficiency (GWE) were generated by a noninvasive pressure-strain loop (PSL) in apical 3-, 4- and 2-chamber views acquired by two-dimensional echocardiography. All obese patients were divided into three groups: class I obesity (mild) 30–35 kg/m2, class II obesity (moderate) 35–40 kg/m2 and class III obesity (severe) > 40 kg/m2. These values were compared among the three groups. The independent influencing factors of subclinical LV systolic dysfunction in obese patients were explored by constructing a multiple regression model. ROC analysis was performed to determine the performance of MW to detect subclinical LV systolic dysfunction in obese patients.ResultsThe absolute value of GLS in obese patients was significantly lower than that in normal controls (P < 0.001). The values of GWI, GCW, GWE and GCW/GWW in obese patients were significantly lower than those in normal controls (P < 0.05), while GWW was significantly larger than that in normal controls (P < 0.001). Subgroup analysis and trend analysis showed that the values of GWI, GCW, GWE and GCW/GWW in severe obese patients were lower than those in moderate obese patients and lower than those in mild obese patients (P < 0.01), while GWW in severe obese patients was larger than that in moderate obese patients and larger than that in mild obese patients (P < 0.05). Female sex, BMI and SBP were independent influencing factors of impaired GWI (β = 0.15, P < 0.001) (β=-0.18, P < 0.001) (β = 0.50, P < 0.001) and GCW (β = 0.17, P < 0.001) (β=-0.19, P < 0.001) (β = 0.57, P < 0.001). ROC analysis showed that the AUC of the combined global MW was significantly higher than the AUCs of the individual indices (P < 0.05).ConclusionIn this study, we conclude that subclinical LV systolic dysfunction was detected by the novel global MW technique in obese patients. Elevated BMI in obese patients results in an increased risk of subclinical LV systolic dysfunction, although the LVEF is normal. Controlling BMI in obese patients may reduce the impairment to the LV myocardial systolic function. Global MW is a novel and reproducible technique that can be well applied in the clinical evaluation of subclinical LV systolic dysfunction.

Association between Impaired Renal Function and Subclinical Myocardial Dysfunction in Patients with Heart Failure with Preserved Ejection Fraction: Assessment Using Noninvasive Pressure-Strain Loop.

The objective of this study was to evaluate the abnormal myocardial function in HFpEF patients with renal dysfunction (RD) and investigate the relationship between renal function and myocardial mechanical characteristics in patients with HFpEF. 134 patients with HFpEF and 32 control subjects were enrolled in our study. Clinical and echocardiography data were collected for offline analysis. Global work index (GWI), global constructive work (GCW), global waste work (GWW), and global work efficiency (GWE) were measured after noninvasive pressure-strain loop analysis. Univariate and multivariate analyses were used to determine the correlation between renal function and myocardial function in patients with HFpEF. In comparison to control subjects, patients with HFpEF tend to have higher GWW (78 [50-115] vs. 108 [65-160] mm Hg%, p &lt; 0.05) and lower GWE (96 [95-97] vs. 95 [92-96] %, p &lt; 0.05), while left ventricular ejection fraction (65.5 ± 3.3 vs. 64.3 ± 4.6%, p &lt; 0.05) was comparable between them. Besides, increased GWW (86 [58-152] vs. 125 [94-187] mm Hg%, p &lt; 0.05) and decreased GWE (96 [93-97] vs. 94 [92-96] %, p &lt; 0.05) were detected in patients with RD compared to those with normal renal function. An independent correlation was found between estimated glomerular filtration rate and GWW after multivariate analysis. More severely impaired myocardial function was detected in HFpEF patients with RD compared to those with normal renal function. Estimated glomerular filtration rate was independently correlated to GWW in patients with HFpEF.

Assessment of subclinical left ventricular myocardial systolic dysfunction in type 2 diabetes mellitus patients with or without hypertension by global and segmental myocardial work

ObjectiveThe research was aimed to evaluate the subclinical left ventricular (LV) myocardial systolic dysfunction in T2DM patients with or without hypertension (HT) by global and segmental myocardial work (MW).MethodsA total of 120 T2DM patients (including 60 T2DM patients with HT) and 70 sex- and age- matched normal controls were included. The global and segmental variables of work index (WI), constrictive work (CW), waste work (WW), work efficiency (WE), and CW/WW were analysed by non-invasive pressure-strain loop. Receiver operating characteristic (ROC) analysis was performed for detection the subclinical LV systolic dysfunction in T2DM patients with and without HT.ResultsThe global work index (GWI), global CW (GCW), global WE (GWE), and GCW/global WW (GWW) of T2DM and T2DM patients with HT were significantly lower than normal controls (p < 0.05). The WI, CW, WE, and CW/WW of the LV anterior wall in T2DM and T2DM patients with HT were significantly lower when compared with those of the normal controls (p < 0.05). ROC analysis showed that the value of area under the curve (AUC) in combined GWI, GCW, GWE, and GCW/GWW was significantly higher than the AUCs of the individual indices (p < 0.05).ConclusionsMW can non-invasively and accurately evaluate subclinical global and segmental LV myocardial systolic dysfunction in T2DM patients with and without HT. Regulating total cholesterol levels and controlling blood pressure in T2DM patients with and without HT might reduce the impairment of LV myocardial systolic function.

Determinants of myocardial work indices in women.

By incorporating myocardial deformation and afterload, novel echocardiographic myocardial work indices appear to be advantageous compared to load-dependent left ventricular (LV) deformation analyses. As such, these indices may provide a more accurate and, above all, load-independent estimation of LV function in patients with chronically increased afterload. To date however, data on the relation of these indices to clinical and conventional echocardiographic parameters are scarce. Our aim was to evaluate the relationship between myocardial work indices and age, body mass index (BMI), NTproBNP, the clinical history of arterial hypertension and diastolic dysfunction as well as selected conventional echocardiographic parameters in women. We analyzed echocardiographic data of women included in the Berlin Female Risk Evaluation (BEFRI) trial. Global Work Index (GWI), Global Constructive Work (GCW), Global Wasted Work (GWW) and Global Work Efficiency (GWE) were calculated using commercially available software based on noninvasive pressure-strain loops. The impact of selected clinical and echocardiographic characteristics on myocardial work parameters was investigated by uni- and multivariate regression analyses. A total of 224 women were included in the final analysis. 155 of them were normotensive and 69 had a history of arterial hypertension. Diastolic dysfunction was more prevalent in subjects with arterial hypertension. Study participants with arterial hypertension showed higher GWI and GCW whereas GWW and GWE did not significantly differ between groups. GCW and GWW were lower and GWE higher in the presence of normal diastolic function. In multivariate regression analyses, arterial hypertension, LV GLS, and interventricular septal thickness were significantly associated with GWI. GCW showed significant associations with the clinical history of arterial hypertension, LV GLS, age and IVRT. Similarly, LV GLS, IVRT and mitral inflow E wave deceleration time were identified to be significant determinants of GWW and GWE. Our data confirm that, in a randomly selected sample of the general urban female population, myocardial work parameters are predominantly determined by LV GLS. In addition, the presence of arterial hypertension was identified to be a significant determinant of GWI and GCW, but not for GWW and GWE. Finally, a prolonged LV relaxation time was significantly associated with GWW and GWE, suggesting more wasted myocardial work and lower GWE values with increasing LV relaxation time.

Global and regional myocardial function assessment in symptomatic patients with chronic coronary syndrome using longitudinal strain and noninvasive myocardial work.

Speckle tracking echocardiography (STE) derived longitudinal strain (LS) and noninvasive pressure-strain loop (PSL) derived myocardial work (MW) are more sensitive than conventional echocardiographic parameters in quantitative assessment of early myocardial dysfunction. The aim of this study was to assess left ventricular (LV) global and regional myocardial function in symptomatic chronic coronary syndrome (CCS) patients using the two promising methods.Transthoracic echocardiography was performed on patients with angina or equivalent symptoms before coronary angiography. STE-based LS and PSL-based MW analysis were carried out on each patient for global and regional myocardial function assessment.A total of 102 patients were classified into significant and nonsignificant coronary artery stenosis (CAS) groups. Among global myocardial function parameters, LS had the biggest area under the curve (AUC) of 0.735, with cutoff value of 18.4% (sensitivity, 79.6%; specificity, 72.9%), but remained statistically alike with all MW indices in predicting significant CAS (P>0.05 for all). Among regional myocardial function parameters, both LS and MW indices had predictive value for significant left anterior descending artery (LAD) or left circumflex artery (LCX) stenosis, while only myocardial work efficiency (MWE) for right coronary artery (RCA) stenosis.Both global and regional LS and MW have predictive value for significant CAS, but their value of regionalized assessment varies with specific coronary artery involvement.

Association Between Segmental Noninvasive Myocardial Work and Microvascular Perfusion in ST-Segment Elevation Myocardial Infarction: Implications for Left Ventricular Functional Recovery and Clinical Outcomes

Predicting left ventricular recovery (LVR) after acute ST-segment elevation myocardial infarction (STEMI) is of prognostic importance. This study aims to explore the prognostic implications of segmental noninvasive myocardial work (MW) and microvascular perfusion (MVP) after STEMI. In this retrospective study, 112 patients with STEMI who underwent primary percutaneous coronary intervention and transthoracic echocardiography after percutaneous coronary intervention were enrolled. Microvascular perfusion was analyzed by myocardial contrast echocardiography, and segmental MW was analyzed by noninvasive pressure-strain loops. A total of 671 segments with abnormal function at baseline were analyzed. The degrees of MVP were observed following intermittent high-mechanical index impulses: replenishment within 4seconds (normal MVP), replenishment >4seconds and within 10seconds (delayed MVP), and persistent defect (microvascular obstruction). The correlation between MW and MVP was analyzed. The correlation of the MW and MVP with LVR (normalization of wall thickening, >25%) was assessed. The prognostic value of segmental MW and MVP for cardiac events (cardiac death, admission for congestive heart failure, or recurrent myocardial infarction) was evaluated. Normal MVP was seen in 70 segments, delayed MVP in 236, and microvascular obstruction in 365. The segmental MW indices were independently correlated with MVP; 244 (36.4%) segments had segmental LVR at 3-month follow-up. Segmental MW efficiency and MVP were independently associated with segmental LVR (P<.05). The χ2 of combination of segmental MW efficiency and MVP was higher than either index alone for identifying segmental LVR (P<.001). At a median follow-up of 42.0months, cardiac events occurred in 13 patients; all regional MW parameters, high sensitivity troponin I, regional longitudinal strain, and so on were associated with cardiac events. Segmental MW indices are associated with MVP within the infarct zone following reperfused STEMI. Both are independently associated with segmental LVR, and regional MW is associated with cardiac events, providing prognostic value in STEMI patients.

Quantitative Assessment of Right Ventricular Function in Patients With Systemic Lupus Erythematosus Using the Novel Non-invasive Pressure-Strain Loop.

Current echocardiography evaluation of right ventricular (RV) function, which heralds the prognosis in patients with systemic lupus erythematosus (SLE), is of limited utility. The non-invasive pressure-strain loop (PSL), an emerging technique, has been found to feasible, sensitive and accurate in the diagnosis of cardiovascular diseases. The aim of this study was to quantitatively evaluate, using the non-invasive PSL, the right ventricular myocardial work (RVMW) in SLE patients. Seventy-five SLE patients were recruited and grouped by pulmonary artery systolic pressure (PASP) into normal (group A, N=26), mild (group B, N=22) and moderate to severe (group C, N=27) groups. Twenty-five healthy volunteers undergoing physical examination were recruited as the control group. Right ventricular global myocardial work index (RVGWI), global constructive work (RVGCW), global wasted work (RVGWW), global work efficiency (RVGWE), global longitudinal strain (RVGLS) and other conventional parameters were measured. There were no differences between group A and the control group with respect to RVLS, RVGLS and all RVMW parameters (all p values > 0.05). RVGWI and RVGCW significantly differed among the other groups (all p values < 0.05). RVGWE was significantly lower and RVGWW was significantly higher in group C than in the control group and groups A and B (all p values < 0.05). Compared with the control group, RVGWW was significantly increased and RVGLS was significantly decreased in group B (all p values < 0.05). All but one RVMW parameter moderately to strongly correlated with SLE disease activity index (SLEDAI) and World Health Organization Functional Class (WHO-FC). RVGWW (area under the receiver operating characteristic curve [AUC]=0.893) and RVGWE (AUC=0.877) were sensitive parameters in detecting earlier cardiac dysfunction in SLE patients. RVGWW and RVGWE serve as sensitive and promising parameters in the integrative analysis of early right ventricular dysfunction in SLE patients. To conclude, non-invasive PSL, the novel method, facilitates the quantitative assessment of RVMW in SLE patients.

Evaluation of left ventricular myocardial work in patients with hyperthyroidism with different heart rates with noninvasive pressure-strain loop based on two-dimensional speck tracking imaging.

We investigated the application value of no-invasive myocardial work in evaluating left ventricular (LV) function in patients with hyperthyroidism. Sixty-five patients with an initial hyperthyroidism diagnosis were sorted into tachycardia (group TH1, n=31) and without tachycardia (group TH2, n=34) groups. Thirty healthy participants served as the control group (group CON). LV strain parameters and LV myocardial work parameters were evaluated at rest. Each parameter's value in identifying myocardial damage was analyzed using receiver operating characteristic curves. The correlation of myocardial work parameters with global longitudinal strain (GLS), longitudinal peak strain dispersion (normalized by heart rate, PSDN), and systolic blood pressure (SBP) was analyzed. There was no difference in classic echocardiographic parameters between the groups. Compared with that in group CON, GLS decreased in groups TH1 and TH2 (TH1 17.99%±2.21% and TH2: 19.00%±2.85% vs. 20.27%±1.49%; both P<0.05); there was no significant difference between groups TH1 and TH2. PSDN increased in groups TH1 and TH2 (TH1 73.13±19.51 ms and TH2 55.06±17.03 vs. 44.13±8.65 ms; both P<0.05); it was higher in group TH1 than in group TH2 (P<0.05). Myocardial global work efficiency (GWE) decreased in groups TH1 and TH2 {TH1 95% [interquartile range (IQR), 94-95%] and TH2 96% (IQR, 95-97%) vs. 97% (IQR, 96-97%); both P<0.05}; it was lower in group TH1 than in group TH2 (P<0.05). Global constructive work (GCW) decreased in group TH1 (1,865.29±284.13 vs. 2,030.33±252.52 mmHg%; P<0.05), but was not different from that in group TH2; there was no difference between groups TH2 and CON. Global wasted work (GWW) increased in groups TH1 and TH2 [TH1 83.00 (IQR, 74.00-97.00) mmHg% and TH2 69.50 (IQR, 51.25-84.25) vs. 50.50 (IQR, 40.75-65.25) mmHg%; both P<0.05]; it was higher in group TH1 than in group TH2 (P<0.05). The area under the GWE curve was the largest (area under the curve =0.835), and the optimal cutoff point was 96.5%, with a sensitivity of 0.83 and a specificity of 0.70. GWE and GCW were positively correlated with GLS and negatively correlated with PSDN. GWW was negatively correlated with GLS and positively correlated with PSDN. In group CON, GCW and GWW were positively correlated with SBP; GWE was not correlated with SBP. In groups TH1 and TH2, GCW was positively correlated with SBP, but not with GWW or GWE. Hyperthyroidism can significantly decrease the GWE and increase GWW of the left ventricle. This change is more pronounced in patients with tachycardia. Myocardial work could be a novel method for the evaluation of LV myocardial function in patients with hyperthyroidism.

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.

Effects of postsystolic shortening and diastolic dyssynchrony on myocardial work in untreated early hypertension patients.

Myocardial work is estimated from noninvasive pressure-strain loop for advanced assessment of left ventricular function. Postsystolic shortening and diastolic dyssynchrony of left ventricle were noted early in hypertension. Their novel effects on myocardial work will be illustrated in this study. We recruited 43 newly diagnosed hypertensive patients (mean age 51.3 ± 12.5 years, 55.8% men) and 32 age-matched and sex-matched healthy individuals (mean age 52.7 ± 10.5 years, 37.5% men) as control. Pressure-strain loop derived myocardial work incorporated global longitudinal strain from speckle tracking echocardiography with brachial artery cuff pressure. Postsystolic strain index (PSI) was defined by the percentage of postsystolic shortening over peak strain. Diastolic dyssynchrony was assessed by standard deviation of time to peak early diastolic strain rate (TDSr-SD) of 18 segments, and maximal difference of time to peak early diastolic strain rate (TDSr-MD) between any two segments. After multivariate regression analysis, global myocardial work index (GWI) was independently correlated with TDSr-SD (B = -0.498, P = 0.001) and TDSr-MD (B = -0.513, P = 0.001). Global myocardial constructive work (GCW) was independently correlated with TDSr-SD (B = -0.334, P = 0.025) and TDSr-MD (B = -0.397, P = 0.007). Global myocardial wasted work (GWW) was independently correlated with PSI (B = 0.358, P = 0.019). Global myocardial work efficiency (GWE) was lower in hypertensive patients than healthy control (P = 0.001). The untreated hypertensive patients were different from the healthy individuals with higher TDSr-SD, TDSr-MD, GWI, GCW, GWW, and PSI (all P < 0.05). In conclusion, the effect of diastolic dyssynchrony mainly influenced constructive work, whereas postsystolic shortening affected wasted work in early untreated hypertension.

Evaluation of myocardial work in patients with hypertrophic cardiomyopathy and hypertensive left ventricular hypertrophy based on non-invasive pressure-strain loops.

BackgroundThe capacity to distinguish hypertrophic cardiomyopathy (HCM) from hypertensive left ventricular hypertrophy (H-LVH) based on morphological features obtained by conventional echocardiography is limited. We investigated the global myocardial work of the left ventricle in two types of hypertrophies using the non-invasive myocardial work index (NMWI).MethodsConventional echocardiography was performed on 107 subjects with preserved left ventricular ejection fraction (LVEF ≥ 50%), who comprised patients with HCM (n = 40), H-LVH (n = 35), and healthy people with normal blood pressure and left ventricular structure (n = 32). Except for the conventional echocardiographic parameters, the left ventricular myocardial work parameters based on pressure-strain loops, including global myocardial work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE), were evaluated in three groups. Multivariate discriminant analysis and receiver operating characteristic (ROC) curve were used to evaluate the incremental value of NMWI for distinguishing HCM from H-LVH.ResultsCompared to the control group, GWI and GCW were significantly lower in HCM patients (P < 0.05), whereas GWI was significantly higher in H-LVH patients. GWW was higher and GWE was significantly decreased in both HCM and H-LVH patients than in the control group (P < 0.05). Multivariate discriminant analysis and ROC curve revealed that the inter-ventricular septum thickness (IVST)/left ventricular posterior wall thickness (LVPWT) and GCW were each able to distinguish HCM from H-LVH. The combination of IVST/LVPWT and GCW discriminated HCM and H-LVH with a higher predictive accuracy of 94.7%.ConclusionNMWI may provide additional information in evaluating the myocardial function in patients with HCM and H-LVH. Myocardial work combined with conventional echocardiography could improve the clinical diagnostic accuracy of distinguishing HCM and H-LVH.

Assessment of left ventricular myocardial work done by noninvasive pressure-strain loop technique in patients with essential hypertension.

To investigate the value of the noninvasive pressure-strain loop (PSL) technique for assessing left ventricular myocardial work done in patients with essential hypertension. Prospectively, 60 patients with hypertension visiting the hospital from August 2020 to July 2021 were collected and divided into the mild hypertension group (SBP 140-159 mmHg, 35 cases) and the moderate-to-severe hypertension group (SBP ≥160 mmHg, 25 cases). Another 40 cases of healthy adults were collected as the control group. The differences in the global long-axis strain (GLS) and peak strain dispersion (PSD) of the left ventricle, global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE) were compared among the three groups. The receiver operating characteristic curve was used to evaluate the PSD, GWI, GCW, and GWW. The myocardial work index (MWI) and MWI percentages in the apical, middle, and basal segments of the heart were also compared among the groups. (1) The PSD, GWI, GCW, and GWW were significantly different among the groups (Χ2 =57.605, 79.203, 76.973, and 17.429, respectively, p < .05), while the GLS and GWE were not (Χ2 =1.559 and 5.849, respectively, p > .05). (2) The GWI had the highest specificity (97.5%) and the GCW the highest sensitivity (95%) in predicting hypertension. The percentage of apical MWI gradually increased (F=11.230, p < .05) and the percentage of basal MWI gradually decreased (F=10.665, p < .05) from the control group to the mild hypertension group to the moderate-to-severe hypertension group; there was no significant difference in the percentage of mid-MWI (F=0.593, p > .05). The noninvasive PSL technique could be used to assess myocardial work done in patients with essential hypertension.

Quantitative assessment of left ventricular systolic function in patients with systemic lupus erythematosus: a non-invasive pressure-strain loop technique.

Systemic lupus erythematosus (SLE) is associated with a variety of cardiovascular diseases, even in the early stage of disease development. The purpose of this study was to quantitatively evaluate left ventricular (LV) systolic function in patients with SLE using a novel non-invasive pressure-strain loop (PSL) technique. This prospective case-control study included 132 patients with SLE and 99 normal controls, all of whom underwent traditional transthoracic echocardiography. The LV myocardial work was evaluated with the PSL technique based on speckle tracking and brachial artery blood pressure. The differences among groups were compared, and the correlations between myocardial work, laboratory data, and disease activity were analyzed in the SLE group. Compared with the normal group, SLE patients had significantly higher global wasted work {GWW; SLE: 109 [82-150] mmHg%; controls: 66 [45-109] mmHg%; P<0.001} and impaired global work efficiency [GWE; SLE: 95% (94-97%); controls: 97% (96-98%); P<0.001]. Global work index (GWI) and global constructive work (GCW) did not show significant differences (P>0.05). Further subdivision analysis found that the increase of GWW and the damage of GWE were more obvious in SLE patients with high disease activity or severe diastolic dysfunction. Multivariate analysis revealed that increased erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), anti-phospholipid antibodies, peak strain dispersion, and SLE Disease Activity Index (SLEDAI) were independently associated with increased GWW (β=0.189, 0.230, 0.444, 0.111, and 0.180, respectively; all P<0.05) and damaged GWE (β=-0.184, -0.130, -0.468, -0.149, and -0.191, respectively; all P<0.05). The non-invasive PSL can quantitatively evaluate the LV systolic function in SLE patients. This technique may provide a new method for monitoring cardiac function in chronic diseases.

Association of myocardial work indices with controlled arterial hypertension, age, weight and conventional echocardiographic parameters in women

Abstract Funding Acknowledgements Type of funding sources: None. Objective By incorporating myocardial deformation and afterload, novel echocardiographic myocardial work indices appear to be advantageous over the load-dependent left ventricular (LV) strain. As such, these indices might provide a better and load-independent estimation of LV function in patients with chronically increased afterload. To date, however, little is known about the relation of these indices to clinical and conventional echocardiographic parameters. Purpose Our aim was to evaluate the relationship between myocardial work indices and age, weight, conventional echocardiographic parameters, and the presence of previously defined well-controlled arterial hypertension (AH) in women without cardiovascular diseases. Methods We retrospectively analyzed echocardiographic data of women, included to the BEFRI (BErlin Female RIsk evaluation) trial. Global Work Index (GWI), Global Constructive Work (GCW), Global Wasted Work (GWW) and Global Work Efficiency (GWE) were calculated using commercially available software based on noninvasive pressure-strain loops. Mulitvariate analysis of covariance was applied to investigate the relation of myocardial work indices with the above mentioned variables. Results A total of 224 women were included in the final analysis. 155 of them were normotensive and 69 had controlled AH. Women with AH were significantly older (67 ± 12 y. vs. 54 ± 13 y, p &amp;lt; 0.05), had higher blood pressure (136 ± 10/77 ± 6 mmHg vs. 121 ± 7/70 ± 6 mmHg, p &amp;lt; 0.05), higher body mass index (28 ± 5 kg/m² vs. 24 ± 4 kg/m², p &amp;lt; 0.05), thicker LV walls (septum: 12 ± 2 mm vs. 9 ± 1 mm; posterior wall: 11 ± 1 mm vs. 9 ± 1 mm, p &amp;lt; 0.05 for both), higher left atrial volume index (35 ± 8 ml/m² vs. 29 ± 5 ml/m², p &amp;lt; 0.05) and longer IVRT (103 ± 27 ms vs. 85 ± 24 ms, p &amp;lt; 0.05). LV ejection fraction, LV internal dimensions and TAPSE were within a normal range and did not differ between groups. Patients with AH showed lower global longitudinal strain (GLS) (19 ± 3% vs. 20 ± 2%, p &amp;lt; 0.05), higher GWI and GCW (2214 ± 285 mmHg% vs. 2045 ± 244 mmHg%, 2445 ± 316 mmHg% vs. 2256 ± 272 mmHg%; p &amp;lt; 0.05 for both) (Fig. 1), whereas GWW and GWE did not differ significantly (112 ± 59 mmHg% vs 101 ± 51 mmHg% and 95 ± 3% vs. 95 ± 2%). In the multivariate analysis GWI and GCW, but not GWW or GWE, were significantly positively associated with the presence of AH (s. Table). Besides that, GWI and GCW were positively related to LVEF and LVEDD. GWW showed negative relation to LVEF and a positive relation with IVRT. GWE was positively related to LVEF, and negatively to IVRT. None of the indices was significantly related to age. Conclusion We have defined the relationship of various myocardial work indices with weight, conventional echocardiographic parameters, and the presence of AH. The higher GWI and GCW in patients with AH might suggest higher energetic expenditure of myocardium due to increased afterload. The prognostic impact of these findings remains to be defined. Abstract Table.

Myocardial performance is impaired in cardiac amyloidosis: role of myocardial work-derived parameter in differential diagnosis with phenocopies and prognostic implications

Abstract Background Cardiac amyloidosis (CA) is an infiltrative disorder characterized by left ventricular (LV) thickening and dysfunction. Due to it poor prognosis its early detection and differential diagnosis among other forms of cardiomyopathies is fundamental. Purpose This study aimed to compare the diagnostic accuracy of LV classical and and novel echocardiographic parameters in differentiating CA from other forms of genetic and non-genetic cardiomyopathies with hypertrophic phenotype. Methods We included 50 patients with CA (26 pts with AL and 24 pts with wild type ATTR form) and 75 patients with LV hypertrophy (LVH) [25 patients with hypertrophic cardiomyopathy (HCM), 25 with hypertensive cardiomyopathy (HypCM), and 25 with aortic stenosis (AS)]. Besides routine echocardiographic measurements, we analysed standard and novel echo parameters implied in LV assessment [LV ejection fraction (LVEF), myocardial contraction fraction (MCF), global longitudinal strain (GLS), relative regional strain ratio (RRSR), ejection fraction on strain ratio (EFSR)], included novel Myocardial Work (MW) parameters [Global Work Index (GWI), Global Constructive Work (GCW), Global Wasted Work (GWW), Global Work Efficiency (GWE)]. Results Patients in CA group showed a smallest LV cavity size, higher LV mass and, consequently, a more pronounced concentric hypertrophy compared to LVH group. All LV systolic parameters where more impaired in CA than in LVH group. At ROC curve analysis, among all others, GCW showed the best performance in discriminating CA from LVH (AUC 0.886; 95% CI: 0.819–0.954; P&amp;lt;0,0001), with a cut-off value &amp;lt;1473 mmHg% showing good sensitivity and specificity (90% and 82%, respectively). At linear regression analysis GCW correlated with IVSD (P&amp;lt;0,0001), PWD (p&amp;lt;0,0001), RWT ratio (p&amp;lt;0,0001), LVMi (p&amp;lt;0,0001), MCF (P&amp;lt;0,0001), LVESV (p&amp;lt;0,002), LVEF (P&amp;lt;0,0001), EFSR (p&amp;lt;0,0001) and RRSR (p&amp;lt;0,0001). At multivariate analysis, PWD (P&amp;lt;0,029) and RWT ratio (p&amp;lt;0,014) were the only parameters associated. At 24 months follow-up there were 15 deaths in the CA group and 4 in LVH group. At Kaplan-Meier analysis the overall survival free of cardiovascular death was reduced in the lowest GCW interquartile ranges (log-rank χ2 21,5; p&amp;lt;0,0001). At Cox hazard ratio analysis GCW (β 1,233; 95% CI: 1,201–1,246; P&amp;lt;0,0001) was the only prognostic parameter associated with cardiovascular mortality. Discussion Although CA and and LVH have with similar phenotype, they differ greatly in terms of systolic function. The MW, estimated by non-invasive pressure-strain loops, is a novel method for a load-independent LV systolic function assessment. In the present study the GCW showed the best ability in detecting CA in comparison to other parameters usually implied in clinical practice. Conclusion Myocardial performance is significantly reduced in CA compared to other forms of LVH. GCW showed to be a promising novel diagnostic and prognostic factor in this setting. Funding Acknowledgement Type of funding sources: None. Table 1Figure 1

Afterload-related reference values for myocardial work indices

BackgroundThe novel noninvasive pressure-strain loop (PSL) is a reliable tool that reflects myocardial work (MW). Systolic blood pressure (SBP) is the only independent factor for MW indices. However, afterload-related reference values have not been previously reported. The aim of the present study was to establish reference values for MW parameters by wide range SBP grading.MethodsWe prospectively selected healthy individuals and subjects with SBP ≥ 140 mmHg at the time of study without myocardial remodeling. MW parameters were collected and the reference values achieved were grouped by SBP in 10-mmHg.ResultsSignificant differences were noted among the SBP-groups for global work index (GWI) and global constructive work (GCW). The majority of statistical comparisons of the differences in GWI and GCW were significant at each SBP-group. With SBP ranging from 90 to 189 mmHg, the parameters GWI and GCW tended to increase linearly with afterload. Overall, the global wasted work (GWW) tended to rise as SBP was increased, but not all of the differences noted in GWW were significant for each SBP-group. Global work efficiency (GWE) remained stable across all SBP-groups, with the exception of a slight drop noted when it exceeded 160 mmHg.ConclusionsThe amount of MW but not the work efficiency varied greatly according to the different afterload. This finding cannot be ignored during clinical research or diagnosis and afterload-related reference values are required to make a reasonable judgment on the myocardial function.

Global work index by non-invasive pressure-strain loops: a novel parameter to assess left ventricular performance in the early stages of heart failure with preserved or mid-range ejection fraction after acute myocardial infarction.

To determine the relationship between myocardial work (MW) indices derived from non-invasive pressure-strain loops (PSL) and established parameters of left ventricular (LV) performance in patients with acute myocardial infarction (AMI) and heart failure (HF) with preserved or mid-range ejection fraction (HFpEF/HFmrEF). Speckle-tracking echocardiography (STE) was used to determine MW indices and global longitudinal strain (GLS) in the first 24-48 hours after admission in patients with AMI, HF symptoms, NT-proBNP >300 pg/mL and left ventricular ejection fraction (LVEF) >40%. MW was calculated by using PSL, which combine strain and non-invasive blood pressure measurement. Global MW index (GWI) was defined as the work inside the area of the PSL. Forty-nine patients (mean age 68±13 years) fulfilled the inclusion criteria. Both GWI (1057±338 mmHg%) and GLS (-10.4±3.3%) were reduced in the majority of the patients. However, a proportion of patients with abnormal GLS showed normal GWI. There was a strong inverse relationship between GWI and GLS (r=-0.81). GWI demonstrated a strong relationship with LVEF (r=0.69) and a moderate correlation to NT-proBNP (n=-0.29). NT-proBNP showed a tendency to higher values in patients with more reduced GWI (820 [590-2550] vs 707 [460-1335], p=0.17). Out of the diastolic dysfunction parameters, GWI showed moderate correlations to LA volume index (r-0.29), E/A (r=-0.23) and E/e' (r=-0.39), which were also significantly more impaired in patients with more reduced GWI. Non-invasive PSL might bring further information to LVEF and GLS in patients AMI at the early stages of HFpEF/HFmrEF, since LV performance depends on both contractile properties and variations in load in the ischemic segments.