Changes and Prognostic Implications of Myocardial Work in Aortic Stenosis Subtypes Undergoing Transcatheter Valve Implantation.

Background: Evaluation of left ventricle (LV) systolic function in patients with aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI) is challenging, as LV ejection fraction (LVEF) and global longitudinal strain are afterload dependent. LV global work indices (GWIs) estimate the afterload corrected systolic function. Objectives: The purpose of this study was to evaluate changes in and prognostic implications of GWIs in subtypes of AS patients before and 1 month after TAVI. Methods: We included 473 patients undergoing TAVI. GWI was estimated using strain imaging and by adding the aortic valve mean gradient to the systolic blood pressure. The primary endpoint was all-cause mortality, evaluated by Cox proportional hazards and Kaplan-Meier curves. Results: High gradient, low flow/low gradient, and normal flow/low gradient AS was found in 48%, 27%, and 25%. In patients with LVEF ≥50% delta GWI decreased from preoperative assessment to 1-month follow-up across all subtypes; high gradient (-353 ± 589 mm Hg%, P < 0.01), low flow/low gradient (-151 ± 652 mm Hg%, P = 0.13), and normal flow/low gradient (-348 ± 606 mm Hg%, P < 0.01). For patients with LVEF <50% delta GWI increased; high gradient 127 ± 491 mm Hg%, P = 0.05; low flow/low gradient 106 ± 510 mm Hg%, P = 0.06; normal flow/low gradient 107 ± 550 mm Hg%, P < 0.27. The median follow-up time was 60 months (IQR: 45-69 months). Each step of 100 mm Hg% higher GWI at pre-TAVI assessment was associated with a reduction in all-cause mortality in multivariable analysis (HR: 0.96 [95% CI: 0.92-1.00], P = 0.033). Conclusions: GWI increases in patients with reduced LVEF after TAVI across AS subtypes whereas GWI decreases in patients with preserved LVEF. Assessment of GWI offers additional prognostic implications beyond LVEF and global longitudinal strain.

Non-Invasive Ultrasound Therapy for Severe Aortic Stenosis: Early Effects on the Valve, Ventricle, and Cardiac Biomarkers (A Case Series).

Background: Transcatheter aortic valve replacement (TAVR) was developed for inoperable patients with severe aortic stenosis. However, despite TAVR advancements, some patients remain untreated due to complex comorbidities, necessitating less-invasive approaches. Non-invasive ultrasound therapy (NIUT), a new treatment modality, has the potential to address this treatment gap, delivering short ultrasound pulses that create cavitation bubble clouds, aimed at softening embedded calcification in stiffened valve tissue. Methods: In the prospective Valvosoft® Serbian first-in-human study, we assessed the safety and efficacy of NIUT and its impact on aortic valve hemodynamics, on the left ventricle, and on systemic inflammation in patients with severe symptomatic aortic stenosis not eligible for TAVR or surgery. Results: Ten patients were included. Significant improvements were observed in hemodynamic parameters from baseline to one month, including a 39% increase in the aortic valve area (from 0.5 cm2 to 0.7 cm2, p = 0.001) and a 23% decrease in the mean transvalvular gradient (from 54 mmHg to 38 mmHg, p = 0.01). Additionally, left ventricular global longitudinal strain significantly rose, while global wasted work significantly declined at one month. A dose-response relationship was observed between treatment parameters (peak acoustic power, intensity spatial-peak pulse-average, and mean acoustic energy) and hemodynamic outcomes. NIUT was safely applied, with no clinically relevant changes in high-sensitivity troponin T or C-reactive protein and with a numerical, but not statistically significant, reduction in brain natriuretic peptide (from 471 pg/mL at baseline to 251 pg/mL at one month). Conclusions: This first-in-human study demonstrates that NIUT is safe and confers statistically significant hemodynamic benefits both on the valve and ventricle.

Non-invasive assessment of left ventricular contractility by myocardial work index in veno-arterial membrane oxygenation patients: rationale and design of the MIX-ECMO multicentre observational study.

Introduction and aims: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is an increasingly utilized therapeutic choice in patients with cardiogenic shock, however, high complication rate often counteracts with its beneficial cardiopulmonary effects. The assessment of left ventricular (LV) function in key in the management of this population, however, the most commonly used measures of LV performance are substantially load-dependent. Non-invasive myocardial work is a novel LV functional measure which may overcome this limitation and estimate LV function independent of the significantly altered loading conditions of VA-ECMO therapy. The Usefulness of Myocardial Work IndeX in ExtraCorporeal Membrane Oxygenation Patients (MIX-ECMO) study aims to examine the prognostic role of non-invasive myocardial work in VA-ECMO-supported patients. Methods: The MIX-ECMO is a multicentric, prospective, observational study. We aim to enroll 110 patients 48-72 h after the initiation of VA-ECMO support. The patients will undergo a detailed echocardiographic examination and a central echocardiography core laboratory will quantify conventional LV functional measures and non-invasive myocardial work parameters. The primary endpoint will be failure to wean at 30 days as a composite of cardiovascular mortality, need for long-term mechanical circulatory support or heart transplantation at 30 days, and besides that other secondary objectives will also be investigated. Detailed clinical data will also be collected to compare LV functional measures to parameters with established prognostic role and also to the Survival After Veno-arterial-ECMO (SAVE) score. Conclusions: The MIX-ECMO study will be the first to determine if non-invasive myocardial work has added prognostic value in patients receiving VA-ECMO support.

Comprehensive Assessment of Cardiac Function in Breast Cancer Patients: Integrating Multiparametric Speckle Tracking Imaging and Conventional Echocardiography Parameters.

Purpose The purpose of this study is to comprehensively evaluate the role of different echocardiography parameters in breast cancer patients undergoing chemotherapy. While echocardiography examination with calculation of ejection fraction (EF), is pivotal for patient monitoring, its operator dependence and insensitivity to subtle changes in left ventricular (LV) contractility present challenges. Global longitudinal strain (GLS), derived from speckle tracking, is more sensitive and stable than EF. Our research aimed to delineate supplementary echocardiography measurements beneficial for the cardiological monitoring of breast cancer patients. Methods Patients were followed up with echocardiography at baseline, during, and after the chemotherapy. Conventional echocardiography and multiple speckle tracking imaging parameters including myocardial work index, atrial strain, twist, and automatic EF were investigated. Results A total of 25 patients were recruited. A subset (15/25) exhibited pronounced GLS reduction, associated with decreased EF and altered cardiac mechanics. Patients with unchanged GLS were often hypertensive and on specific medications, in particular angiotensin-converting enzyme inhibitors (ACE inhibitors)/angiotensin II receptor blockers (ARBs), potentially indicating protective effects. Despite stability in other parameters, GLS and EF sensitivity highlight their importance. A strong correlation between manual and automated EF measurement methods was also observed. Conclusion Despite the small sample size, across diverse echocardiography parameters, GLS and EF are primarily affected by chemotherapy. Hypertensive individuals exhibited lower susceptibility to chemotherapy-induced damage, likely attributed to the cardioprotective properties of ACE inhibitors and angiotensin II receptor blockers. A strong correlation between automatic and Simpson-based EF was found.

Usability of myocardial work parameters to demonstrate subclinical myocardial involvement in normotensive individuals with exaggerated hypertensive response in treadmill exercise testing.

Early determination of changes in myocardial functions is essential for the protection of cardiovascular diseases. This study aimed to evaluate myocardial work parameters in healthy individuals who developed an exaggerated hypertensive response during the treadmill exercise test procedure. The study included a total of 64 patients for whom an exercise electrocardiography test was planned for functional capacity evaluation. The study population was divided according to the presence of exaggerated hypertensive response to exercise (EBPRE) (SBP/DBP ≥210/105 mmHg in males ≥190/105 mmHg in females) and normal blood pressure response to exercise (NBPRE). Patients' echocardiographic evaluations were made at rest, and myocardial work parameters were calculated. There was no statistical difference between the groups (NBPRE vs. EBPRE, respectively) in terms of left ventricular 2,3 and 4 chamber strains and global longitudinal strain (GLS) values (-20.6 ± -2.3, -19.7 ± -1.9, p:.13; -21.3 ± -2.7, -21 ± -2.4, p:.68; -21.2 ± -2.2, -21.2 ± -2.3, p:.93; and -20.8 ± -1.5, -20.4 ± -1.5, p:.23, respectively). Global constrictive work (GCW), global waste work (GWW), and global work efficiency (GWE) were not statistically different between the two groups (2374 ± 210, 2465 ± 204, p:.10; 142 ± 64, 127 ± 42, p:.31; 94.3 ± 2.5, 95.1 ± 1.5, p:.18, respectively). In contrast, global work index (GWI) parameters were different between the two groups (2036 ± 149, 2147 ± 150, p < .001). The GWI was independently associated with EBPRE (odds ratio with 95% 3.32 (1.02-11.24), p = .03). The partial effect plots were used for GWI to predict EBPRE, according to the results, an increase in GWI predicts probability of exaggerated hypertensive response. In conclusion, Myocardial work analyses might be used to identify early signs of myocardial involvement in normotensive patients with EBPRE.

Right ventricular pressure-strain relationship-derived myocardial work reflects contractility: Validation with invasive pressure-volume analysis.

Three-dimensional (3D) echocardiography-derived right ventricular (RV) ejection fraction (EF) and global longitudinal strain (GLS) are valuable RV functional markers; nevertheless, they are substantially load-dependent. Global myocardial work index (GMWI) is a novel parameter calculated by the area of the RV pressure-strain loop. By adjusting myocardial deformation to instantaneous pressure, it may reflect contractility. To test this hypothesis, we enrolled 60 patients who underwent RV pressure-conductance catheterization to determine load-independent markers of RV contractility and ventriculo-arterial coupling. Detailed 3D echocardiography was also performed, and we calculated RV EF, RV GLS, and using the RV pressure trace curve, RV GWMI. While neither RV EF nor GLS correlated with Ees, GMWI strongly correlated with Ees. In contrast, RV EF and GLS showed a relationship with Ees/Ea. By dividing the population based on their Reveal Lite 2 risk classification, different characteristics were seen among the subgroups. RV GMWI may emerge as a useful clinical tool for risk stratification and follow-up in patients with RV dysfunction.

Non-invasive myocardial work in aortic stenosis: validation and improvement in left ventricular pressure estimation.

AIMS: The non-invasive myocardial work index (MWI) has been validated in patients without aortic stenosis (AS). A thorough assessment of methodological limitations is warranted before this index can be applied to patients with AS. METHODS AND RESULTS: We simultaneously measured left ventricular pressure (LVP) by using a micromanometer-tipped catheter and obtained echocardiograms in 20 patients with severe AS. We estimated LVP curves and calculated pressure-strain loops using three different models: (i) the model validated in patients without AS; (ii) the same model, but with pressure at the aortic valve opening (AVO) adjusted to diastolic cuff pressure; and (iii) a new model based on the invasive measurements from patients with AS. Valvular events were determined by echocardiography. Peak LVP was estimated as the sum of the mean aortic transvalvular gradient and systolic cuff pressure. In same-beat comparisons between invasive and estimated LVP curves, Model 1 significantly overestimated early systolic pressure by 61 ± 5 mmHg at AVO compared with Models 2 and 3. However, the average correlation coefficients between estimated and invasive LVP traces were excellent for all models, and the overestimation had limited influence on MWI, with excellent correlation (r = 0.98, P < 0.001) and good agreement between the MWI calculated with estimated (all models) and invasive LVP. CONCLUSION: This study confirms the validity of the non-invasive MWI in patients with AS. The accuracy of estimated LVP curves improved when matching AVO to the diastolic pressure in the original model, mirroring that of the AS-specific model. This may sequentially enhance the accuracy of regional MWI assessment.

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.

Myocardial Work Evaluation-A Useful Non-Invasive Method to Predict Coronary Artery Sub-Occlusion in a Patient with Unstable Angina and Multiple Myocardial Revascularization Interventions.

BACKGROUND: While lifestyle changes, management of coronary artery disease (CAD) risk factors, myocardial revascularization procedures, and medication can improve a patient's prognosis, de novo native coronary lesions and in-stent restenosis (ISR) remain significant clinical concerns. ISR is more frequent with a bare-metal stent than with a drug-eluting stent and has been documented in around 12% of DES patients. Acute coronary syndrome (ACS) manifests as unstable angina in about 30% to 60% of ISR patients. Myocardial work imaging is a modern, non-invasive technique able to identify individuals with critical coronary artery lesions with high sensitivity and specificity. CASE REPORT: We present the case of a 72-year-old Caucasian gentleman with multiple cardiovascular risk factors, admitted to the Cardiology Clinic of Timișoara Municipal Hospital with unstable angina. From 1999 to 2021, the patient experienced two myocardial infarctions, a double aortocoronary bypass graft, and multiple percutaneous coronary interventions with 11 stent implantations, including 6 for ISR. Using two-dimensional speckle-tracking echocardiography and myocardial work assessment, we detected that the lateral wall of the left ventricle had a severely impaired deformation pattern. Angio-coronarography was performed, and sub-occlusion of the posterolateral branch of the right coronary artery was found. Angioplasty was performed and a DES was inserted, with a good final angiographic result and complete release of symptoms. CONCLUSION: In patients with a history of multiple myocardial revascularization interventions and ISR, it is challenging to identify the critical ischemia region by non-invasive methods. Myocardial work imaging was beneficial in the detection of the altered deformation patterns indicating significant ischemia, its accuracy being superior to that of LV strain, as proven by coronary angiography. Urgent coronary angiography followed by angioplasty and stent implantation resolved the issue.

Left Ventricular Systolic Function After 3 Months of SGLT2 Inhibitor Therapy in Heart Failure Patients with Reduced Ejection Fraction.

Not much is known about the effects of sodium-glucose cotransporter 2 inhibitors (SGLT2i) on echocardiographic parameters of left ventricular (LV) systolic function in patients with heart failure and reduced ejection fraction (HFrEF).We prospectively included 59 outpatients with HFrEF: 41 patients received SGLT2i with OMT (SGLT2i+ group), whereas eighteen patients received OMT without SGLT2i (SGLT2i- group). Myocardial work index (MWI), 3D ejection fraction (3D LVEF), and global longitudinal strain (GLS) were measured at baseline and after 3 months following treatment. At 3-month follow-up, the SGLT2i+ group showed significantly greater improvement in MWI than the SGLT2i- group. In both groups, there was a significant improvement in 3D LVEF and LV GLS, circulating NT-proBNP levels, and NYHA functional class, with significantly greater improvement in the SGLT2i+ group.In conclusion, the addition of SGLT2i to fully optimized background medical therapy resulted in a greater improvement of LV systolic function among outpatients with HFrEF.

Left ventricular myocardial work index and short-term prognosis in patients with light-chain cardiac amyloidosis: a retrospective cohort study.

Background: Reports show that the left ventricular myocardial work index (LVMWI) is a novel parameter for evaluating cardiac function. Decompensated heart failure leads to a high rate of early mortality in advanced patients with light-chain cardiac amyloidosis (AL-CA) and prevents them from a relatively delayed response to chemotherapy. This study aimed to assess the association of the LVMWI with short-term outcomes and to construct a simple model for risk stratification. Methods: A total of 79 patients with an initial diagnosis of AL-CA were included in this retrospective cohort study. LVMWI was calculated by integrating brachial artery cuff blood pressure and left ventricular longitudinal strain (LVLS). The short-term outcome was defined as 6-month all-cause mortality. Receiver operating characteristic (ROC), logistic regression, and Kaplan-Meier analysis were used in this study. Results: The median follow-up time was 21 months (3-36 months), and 23 (29%) patients died in the first 6 months. The time-dependent ROC and the area under the curve (AUC) showed that the LVMWI had the best predictive potential at the 6-month time point [AUC =0.805; 95% confidence interval (CI): 0.690-0.920]. A bivariate prognostic model based on the LVMWI was constructed, and D-dimer showed a synergistic effect with optimum predicted potential (AUC =0.877; 95% CI: 0.791-0.964). Kaplan-Meier analysis demonstrated that patients with two, one, and none of the variates beyond the cut-off value bore a different risk of 6-month all-cause mortality (accumulated mortality was 86%, 30%, 3%, respectively; log-rank, P<0.001). Multivariate nested logistic regression showed that the level of D-dimer provided an incremental prognostic value (Δχ2=10.3; P=0.001) to the value determined from New York Heart Association (NYHA) classification and the LVMWI. Conclusions: The LVMWI is associated with the short-term outcome of patients with AL-CA. The D-dimer test provides additional prognostic information for the LVMWI.

Impact of arterial stiffness on echocardiographic myocardial work indices in patients with isolated bicuspid aortic valve.

OBJECTIVE: Data related to the existence of left ventricular (LV) abnormalities in normal functional bicuspid aortic valve (BAV) disease is scarce. In addition, the impact of afterload and the involved mechanisms are unclear. In this work, we study the relationship between LV function assessed with myocardial work index (MWI) and arterial stiffness in a cohort of normal functioning BAV patients. METHODS: In this study, we included a total of 38 consecutive patients with isolated BAV and 44 age- and gender-matched control subjects with tricuspid aortic valve. All participants underwent transthoracic echocardiography to assess conventional parameters and global longitudinal strain (GLS). In addition, MWI was measured by the noninvasive LV pressure-strain cycle method. Aortic pulse wave velocity (PWV) and wave reflection were evaluated by applanation tonometry. RESULTS: The mean aortic PWV was significantly higher in BAV patients (6.4 ± 0.80, 7.02 ± 0.1.2, p = .01, respectively). LV-MWI related parameters such as global work efficiency (GWE) (96.261.69 and 97.051.27, p = .02) and global wasted work (GWW) (78.232.1 and 61.824.4, p = .01) were found significantly different between the BAV and control groups. However, global working index and global constructive working were not different between groups (1969 ± 259 and 2014 ± 278, p = .45; 2299 ± 290 and 2359 ± 345, p = .39, respectively). Multivariable ordinary least squares regression analysis revealed that BAV (ß = 8.4; 95% CI: 1.5-15.3; p = .04) and PVW (ß = 5.6; 95% CI: 0.7-10.5; p = .01) were significant predictors of GWV. CONCLUSION: GWW is increased and GWE is decreased in patients with BAV compared with controls, and these changes are related to arterial stiffness. The relationship between aortic PWV and GWW may help to explain the exact mechanism of subclinical myocardial dysfunction in patients with isolated BAV.

Predictive value of the echocardiographic noninvasive myocardial work index for left ventricular reverse remodeling in patients with multivessel coronary artery disease after percutaneous coronary intervention.

Background: Coronary artery disease (CAD) can lead to left ventricular (LV) remodeling, which, in adverse cases, has been associated with heart failure and increased mortality. Here, we aimed to evaluate the predictive value of the noninvasive myocardial work index (NIMWI) for LV reverse remodeling in patients with multivessel CAD after percutaneous coronary intervention (PCI). Methods: A total of 88 consecutive patients with multivessel CAD treated with PCI were identified and categorized according to the presence of LV reverse remodeling 3 months after PCI [≥15% decrease in the LV end diastolic volume (LVEDV)]. With the LV pressure-strain loop (PSL) technique, NIMWIs, including the global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE), were statistically compared between the reverse LV remodeling group and nonreverse LV remodeling group 1 week before PCI. Results: Significantly lower GWI, GCW, and GWE, and significantly higher GWW were observed in the reverse LV remodeling group compared with the nonreverse LV remodeling group (P<0.05). Left ventricular mass index (LVMI), GCW, and GWE were independently associated with early LV reverse remodeling. Receiver operating characteristic (ROC) curve analysis demonstrated that GCW was the most powerful predictor of early LV reverse remodeling in patients with CAD [area under the curve (AUC) =0.867]. The optimal cutoff GCW value predictive of early LV reverse remodeling was 1,438.5 mmHg% (sensitivity, 85%; specificity, 70%). Conclusions: GCW, among the NIMWIs, may be the major predictor of LV reverse remodeling in patients with multivessel CAD after PCI. NIMWI could potentially provide a new reference index for the quantitative evaluation of LV myocardial work.

Effect of tafamidis on global longitudinal strain and myocardial work in transthyretin cardiac amyloidosis.

AIMS: In patients with transthyretin amyloid cardiomyopathy (ATTR-CM), the effect of tafamidis on myocardial function using serial speckle tracking echocardiography has not been reported. The purpose of this study was to describe the natural history of myocardial function in untreated ATTR-CM and determine the effect of tafamidis on myocardial functional parameters over 12 months of treatment. METHODS AND RESULTS: A total of 45 subjects with ATTR-CM were retrospectively studied: 23 treated with tafamidis and 22 untreated. Two-dimensional speckle tracking echocardiography was analysed at baseline and 1 year. Serial longitudinal, circumferential, and radial strain, twist, torsion, and myocardial work were measured. Over 1 year, absolute global longitudinal strain (GLS) deteriorated more in the untreated group by a median of 1.1% [inter-quartile range (IQR) 0.95] compared with 0.3% (IQR 1) in the tafamidis group (P = 0.02). Myocardial work index and efficiency also deteriorated to a greater degree: 142.5 mmHg% (IQR 197) and 4% (IQR 8), respectively, in the untreated group compared with 61.5 mmHg% (IQR 210) and 1% (IQR 7) in the tafamidis group (P = 0.04). There were no significant between group differences in left ventricular ejection fraction (LVEF), tissue Doppler velocities, circumferential or radial strain, LV twist or torsion at 1 year. The stabilization effect of tafamidis on myocardial function at 1 year did not differ according to baseline GLS, LVEF, or National Amyloidosis Centre disease stage. CONCLUSIONS: In ATTR-CM, tafamidis resulted in a lesser deterioration in GLS, myocardial work index, and efficiency over a 12-month period compared with a cohort not treated with tafamidis.

Changes in cardiac function following a speed ascent to the top of Europe at 4808 m.

PURPOSE: Both prolonged exercise and acute high-altitude exposure are known to induce cardiac changes. We sought to describe the cardiac responses to speed climbing at high-altitude, including left ventricular (LV) performance assessment using the myocardial work index (MWI), a new index derived from 2D speckle tracking echocardiography (STE). METHODS: Eleven elite alpinists (9 males, age: 26 ± 4 years) were evaluated before and immediately after a speed ascent of the Mont-Blanc (4808 m) by echocardiography using conventional measurements as well as STE and MWI computation with derivate parameters as global work efficiency (GWE) or global wasted work (GWW). RESULTS: Athletes performed a long-duration (8 h 58 min ± 60 min) and intense (78 ± 4% of maximal heart rate) ascent under gradual hypoxic conditions (minimal SpO2 at 4808 m: 71 ± 4%). Hypoxic exercise-induced cardiac fatigue was observed post-ascent with a change in right ventricular (RV) and LV systolic function (RV fractional area change: - 20 ± 23%, p = 0.01; LV global longitudinal strain change: - 8 ± 9%, p = 0.02), as well as LV geometry and RV-LV interaction alterations with emergence of a D-shape septum in 5/11 (46%) participants associated with RV pressure overload (mean pulmonary arterial pressure change: + 55 ± 20%, p < 0.001). Both MWI and GWE were reduced post-ascent (- 21 ± 16%, p = 0.004 and - 4 ± 4%, p = 0.007, respectively). Relative decrease in MWI and GWE were inversely correlated with increase in GWW (r = - 0.86, p = 0.003 and r = -0.97, p < 0.001, respectively). CONCLUSIONS: Prolonged high-altitude speed climbing in elite climbers is associated with RV and LV function changes with a major interaction alteration. MWI, assessing the myocardial performance, could be a new tool for evaluating LV exercise-induced cardiac fatigue.