Left Ventricular Mechanical Dispersion Research Articles

Anthracycline-induced cardiotoxicity on regional myocardial work and left ventricular mechanical dispersion in adolescents and young adults in post-lymphoma remission.

Myocardial work (MW) is a new echocardiographic tool with a high sensitivity to detect early and subtle alterations of myocardial function. We aimed to evaluate the late effects of anthracyclines by assessing the global and segmental MW and intraventricular mechanical dispersion from speckle tracking echocardiography in childhood lymphoma survivors (CLS). Thirty-one young adults including CLS and age-matched healthy controls were enrolled. All underwent echocardiography including an evaluation of left ventricular (LV) morphology and regional function. We assessed LV longitudinal (differentiating sub-endocardial and sub-epicardial layers), circumferential strains and twist, global and regional MW index (MWI). LV mechanical dispersion was assessed from the time dispersion of LV longitudinal strain, from myocardial wasted work (MWW) and myocardial work efficiency (MWE). The longitudinal strains both at the level of the sub-endocardium and sub-epicardium were reduced in CLS compared to controls. The global MWI was also decreased (1668 ± 266 vs 1870 ± 264%.mmHg in CLS patients and controls, respectively, p < 0.05), especially on the apical segments. An increase of LV intraventricular mechanical dispersion was observed in CLS. MWW and MWE remained unchanged compared to controls. Our results strongly support that cardiac remodeling is observed in CLS, characterized by a decrease in MW and an increase in LV mechanical dispersion. The apex is specifically altered, but its clinical significance remains uncertain. MW as a complement to strain seems interesting in cancer survivors to detect myocardial dysfunction at early stage and adapt their follow-up.

Left ventricular mechanical dispersion as a predictor of the need for pacemaker implantation after transcatheter aortic valve implantation: MeDiPace TAVI study.

Permanent pacemaker (PM) implantation is common after transcatheter aortic valve implantation (TAVI). Left ventricular mechanical dispersion (MeDi) by speckle tracking echocardiography is a marker of fibrosis that causes alterations in the conduction system. We hypothesized that MeDi can be a predictor of the need for PM implantation after TAVI. Consecutively, 200 TAVI patients were enrolled. Transthoracic echocardiography and electrocardiography examinations were recorded before TAVI to evaluate global longitudinal strain (GLS), MeDi, and conduction disturbances. PM implantation information was obtained 3 months after TAVI. Patients were stratified into PM or no PM group. Mean age was 80 + 7 years (44% women). Twenty-nine patients (16%) received PM. MeDi, QRS duration, existence of right bundle branch abnormality (RBBB), and first-degree atrioventricular (AV) block were significantly different between groups. MeDi was 57 ± 15 ms and 48 ± 12 ms in PM and no PM groups, respectively (P < 0.001). In multivariate analysis, MeDi predicted the need for PM after TAVI independently of GLS, QRS duration, RBBB, and first-degree AV block [odds ratio (OR): 1.73, 95% confidence interval (CI): 1.22-2.45] with an area under the curve (AUC) of 0.68 in receiver operating characteristic (ROC) curves. Moreover, RBBB was an independent predictor of PM need after TAVI (OR: 8.98, 95% CI: 1.78-45.03). When added to RBBB, MeDi had an incremental predictive value with an AUC of 0.73 in ROC curves (P = 0.01). MeDi may be used as an echocardiographic functional predictor of the need for PM after TAVI.

Myocardial Mechanical Dispersion Predicts Adverse Cardiac Remodeling in Patients with ST Segment Elevation Myocardial Infarction Who Underwent Primary Percutaneous Coronary Intervention.

The aim of the study was to investigate whether increased left ventricular mechanical dispersion is an early predictor for adverse cardiac remodeling in ST-segment elevation myocardial infarction patients who had post-percutaneous coronary intervention thrombolysis in myocardial infarction (TIMI) flow grade > 2. A total of 119 post-percutaneous coronary intervention ST elevation myocardial infarction patients with TIMI flow grade >2 were prospectively included in the study. Left ventricular global longitudinal strain was quantified by 2-dimensional speckletracking echocardiography, and left ventricular mechanical dispersion was determined at baseline and after 1 year to assess adverse cardiac remodeling. The levels of circulating biomarkers were measured at the baseline. TIMI score and the Global Registry of Acute Coronary Events score systems were used to evaluate the prognosis of patients. Patients with high quartile versus low quartile of left ventricular mechanical dispersion exerted higher Global Registry of Acute Coronary Events and TIMI score grades, left ventricular endsystolic volume, global longitudinal strain, and levels of the N-terminal fragment of brain natriuretic peptide and lower left ventricular ejection fraction. Multivariate log regression showed that N-terminal fragment of brain natriuretic peptide > 953 pg/mL, global longitudinal strain > -8%, and high quartile of left ventricular mechanical dispersion remained independent predictors for adverse cardiac remodeling. Addition of left ventricular mechanical dispersion to the N-terminal fragment of brain natriuretic peptide improved the discriminative potency of the whole model. Measurement of left ventricular mechanical dispersion might be useful in determining the risk of adverse cardiac remodeling in post-percutaneous coronary intervention ST elevation myocardial infarction patients.

The implication of left ventricular mechanical dispersion as a risk predictor for ventricular arrhythmias in patients with mitral valve prolapse

The implication of left ventricular mechanical dispersion as a risk predictor for ventricular arrhythmias in patients with mitral valve prolapse

Left ventricular mechanical dispersion by speckle tracking echocardiography is a predictor of atrioventricular block after transcatheter aortic valve implantation

Abstract Background Transcatheter Aortic Valve Implantation (TAVI) is an effective therapy for patients with severe aortic stenosis (AS). Complete atrioventricular block (AVB) that requires permanent pacemaker implantation is a common complication of TAVI. Direct mechanical effect of the prosthetic valve, QRS duration and underlying myocardial fibrosis are proposed mechanisms of AVB after TAVI. Left ventricular mechanical dispersion (LVMD) by Speckle Tracking Echocardiography (STE) is an index of contraction heterogeneity and a marker of myocardial fibrosis. Purpose We aimed to evaluate the association between LVMD, QRS duration and AVB to assess markers used to predict AVB after TAVI. Methods A total of 163 consecutive TAVI patients were enrolled in the study. Echocardiograms andelectrocardiograms were recorded the day before TAVI procedure to assess global longitudinal strain (GLS), LVMD and QRS duration. AVB and pacemaker (PM) implantation information was obtained by telephone interviews three months after TAVI. Results Ten patients were excluded due to poor image quality. Of the 153 patients analyzed, 45% were female. Mean age was 80±7 years. In our patient cohort 15.7% of the patients received PM within three months after TAVI. GLS and QRS duration was not different between AVB group and No-AVB group (−15.8±4.5% vs −16.9±4.4%, p=0.26 and 107±31ms vs 102±18ms, p=0.24 respectively). LVMD was prolonged in patients with subsequent AVB compared to patients with No-AVB (60±19ms vs 48±13ms, p&amp;lt;0.001) (Figure 1). LVMD predicted AVB after TAVI with area under the curve 0.71. LVMD predicted AVB independently of QRS duration (odds ratio 1.68; 95% confidence interval 1.23–2.3; p=0.001 by 10ms increments) (Table 1). Conclusion LVMD predicted AVB after TAVI independent of QRS duration. LVMD may be of added value as a myocardial functional echocardiographic predictor of this important and frequent complication of TAVI. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): EACVI Research Grant 2020

Prognostic value of left ventricular global longitudinal strain and mechanical dispersion by speckle tracking echocardiography in patients with ischemic and nonischemic cardiomyopathy: a systematic review and meta-analysis

Aim. To conduct a systematic review and meta-analysis in order to evaluate the prognostic value of left ventricular global longitudinal strain (LV GLS) and LV mechanical dispersion (LVMD) in ischemic and nonischemic cardiomyopathy.Material and methods. We searched PubMed, Google Scholar and Embase for studies on the prognostic value of LV GLS and LVMD in ischemic and nonischemic cardiomyopathy. Hazard ratios (HR) from included studies were pooled for metaanalysis.Results. Twelve studies were selected from 314 publications for this systematic review and meta-analysis. In total, 2624 patients (mean age, 57,3 years; mean follow-up, 40,8 months) were included in the analysis. Meta-analysis showed that decreased LV GLS was associated with an increased risk of ventricular arrhythmias (VAs) (adjusted HR: 1,10 per 1% of GLS; 95% CI: 1,01-1,19; p=0,03) and major adverse cardiovascular events (MACE): adjusted HR: 1,22 per 1% of GLS; 95% CI: 1,11-1,33; p&lt;0,0001). Patients with VAs had greater LVMD than those without it (weighted mean difference, 33,69 ms; 95% CI: -41,32 to -26,05; p&lt;0,0001). Each 10 ms increment of LVMD was significantly and independently associated with VA episodes (adjusted HR: 1,18; 95% CI: 1,08-1,29; p=0,0002).Conclusions. LV GLS and LVMD assessed using speckle tracking provides important predictive value and can be used as an effective tool for stratifying risk in patients with ischemic and nonischemic cardiomyopathy.

Behind Enemy Lines: Vital Echocardiographic Data Prior to Ventricular Arrhythmia Ablation

Ventricular arrhythmias (VA) are a major cause of sudden cardiac death (SCD). Echocardiography is the first widely available imaging tool which guides VA management strategies. Along with other invasive and noninvasive imaging techniques, it provides essential information for identification of VA substrate such as differentiation between ischemic and non-ischemic etiology and identification of structural heart disease. Both classic as well as novel echocardiographic techniques such as left ventricular strain measurement and mechanical dispersion assessment provide prognostic information and assist in risk stratification. Furthermore, intracardiac echocardiography may have an adjunctive role for the VA ablation by providing real-time visualization of cardiac structures, continuous monitoring of catheter location and early recognition of procedural complications. This review gathers all relevant information that echocardiography may offer prior to VA ablation procedures.

Normative Reference Values of Left Ventricular Mechanical Dispersion Assessed by Two-Dimensional Longitudinal Speckle-Tracking Strain in Normal Subjects

Normative Reference Values of Left Ventricular Mechanical Dispersion Assessed by Two-Dimensional Longitudinal Speckle-Tracking Strain in Normal Subjects

Impaired left ventricular systolic synchrony in patients with lupus Nephritis: A speckle tracking echocardiography study.

We aimed to explore the value of two-dimensional speckle tracking echocardiography measurements of the global longitudinal strain (GLS) and left ventricular mechanical dispersion (LVMD) in the assessment of early stage left ventricular systolic dysfunction and heterogeneity of myocardial contraction in patients with lupus nephritis (LN). Patients with LN and extra-renal systemic lupus erythematosus (SLE) and healthy participants in the control group underwent echocardiography for the traditional measurement of the left ventricular systolic and diastolic function and speckle tracking measurements of the GLS and LVMD. GLS was defined as the average value of the peak strain during systole of the left ventricular 17 segments, and LVMD was defined as the standard deviation. The demographic characteristics including age, sex, and body mass index (BMI) of all the participants were collected. The clinical and laboratory characteristics of the patients with LN were collected. We included 41 healthy control, 37 patients with extra-renal SLE, and 73 patients with LN. There were statistically significant differences in the GLS and LVMD between the extra-renal SLE and LN groups (GLS -19.36% vs. -17.61%, p < 0.001; LVMD 35.62ms vs 42.96ms, p<0.001). There was a statistically significant difference in the LVMD between the extral-renal SLE and control groups (35.62ms vs 25.51ms, p<0.001), but not in GLS (-19.36% vs -19.52%, p > 0.05). Multiple regression analyses were conducted in a subset of patients, and 24-hour proteinuria was independently associated with LVMD (β [SE], 0.793 [0.302], p < .05). Patients with LN have more severe myocardial involvement than patients with extra-renal SLE. The asynchrony in myocardial contraction represented by the LVMD can be recognized earlier than that of the overall contractile functional impairment represented by GLS. In patients with LN, the 24-hour proteinuria was associated with LVMD. This indicates that the heterogeneity in the contractile function may be associated with the severity of renal damage.

Mechanical dispersion combined with global longitudinal strain estimated by three dimensional speckle tracking in patients with ST elevation myocardial infarction.

The role of left ventricular (LV) mechanical dispersion estimated after an ST elevation acute myocardial infarction (STEMI) remains unclear. The study participants were 208 consecutive patients (152 men, age=72years) presenting with STEMI for the first time who underwent primary percutaneous coronary intervention (PCI) within 12h of STEMI onset. Within 48h of PCI (mean=24h), 2D and 3D speckle-tracking echocardiography were performed. The global longitudinal strain (GLS) was calculated using 3D (3D-GLS) and 2D (2D-GLS) speckle tracking. Mechanical dispersion was defined using the standard deviation (SD) of the time to regional peak longitudinal strain (LS) for all 16 segments for both 2D-STE and 3D-STE (2D-LS-SD, 3D-LS-SD). Infarct size was estimated by Tc99m-sestamibi as the total area of<50% of the uptake area at 2weeks. The patients were followed up for a longer period of time (median118months) and checked for major adverse cardiac events (MACE: cardiac death, heart failure). During follow-up, 55 patients experienced MACE. The cut-off values were determined using receiver operating characteristic curves. The multivariate analysis revealed that a 3D-LS-SD>56.7ms was a significant predictor of MACEs (hazard ratio=1.991, 95% confidence interval 1.033-3.613, p=0.03), but 2D-LS-SD>58.1ms was not an independent predictor of MACEs (hazard ratio=1.577, 95% confidence interval 0.815-3.042, p=0.1). Furthermore, the combination of 3D-GLS and 3D-LS-SD had accurate predictability for MACE, as shown by the Kaplan-Meier curves (log rank, χ2=94.1, p<0.0001). LV mechanical dispersion besides 3D-GLS assessed by 3D-STE immediately after PCI can predict long-term prognosis.

Evaluation of left atrial function and mechanical dispersion in breast cancer patients after chemotherapy.

BackgroundLeft atrial (LA) function and mechanical dispersion changes in breast cancer patients treated with chemotherapy remain unclear.HypothesisLA function and LA mechanical dispersion in breast cancer patients would be impaired after chemotherapy.MethodsThis single‐center retrospective study included 91 consecutive breast cancer patients treated with chemotherapy and 30 controls. Patients were examined by echocardiography three times at intervals. Conventional parameters, left ventricular strain, LA strain, and LA mechanical dispersion were evaluated and compared.ResultsLA strain during reservoir phase (LASr), conduit phase (LAScd), and contraction phase (LASct) all decreased markedly after chemotherapy and were lower than those of the controls (all p < .01). The standard deviation of time to peak positive strain during LA reservoir phase corrected by R‐R interval (LA SD‐TPSr) was significantly increased after chemotherapy and was higher than that of the controls (p < .001). The change of LA function was expressed as Δ. Multivariate linear regression analyses showed that LAVIp (0.399, 95% confidence interval [CI]: 0.610, 1.756, p = .000) was independently associated with ΔLASr, LAPEF (−0.325, 95% CI: −45.123, −10.676, p = .002) and age (0.227, 95% CI: 0.021, 0.350, p = .027) were independently associated with ΔLAScd, and LAVImax (0.341, 95% CI: 0.192, 0.723, p = .001) was independently associated with ΔLASct. LAVImax (0.505, 95% CI: 0.000, 0.001, p = .039) and mitral E (−0.256, 95% CI: 0.000, 0.000, p = .024）were independently associated with ΔLA SD‐TPSr.ConclusionsMechanical function of LA declined after chemotherapy in breast cancer patients. With the decrease of LA mechanical function, LA mechanical dispersion assessed by two‐dimensional speckle‐tracking echocardiography increased significantly, and its clinical value needs to be further studied.

Associations between cardiovascular risk factors, biomarkers, and left ventricular mechanical dispersion: insights from the ACE 1950 Study.

AimsMechanical dispersion measures left ventricular contraction heterogeneity and is associated with the risk of sudden cardiac death. However, the associations between mechanical dispersion and cardiovascular risk factors in early mid-life, and established biomarkers of sub-clinical myocardial injury and dysfunction are not known. We aimed to examine this in the general population.Methods and resultsDuring 2012–15, we included 2527 Norwegian individuals from the general population born in 1950, with measurements of mechanical dispersion by 2D speckle tracking echocardiography and concentrations of high-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) available. Mechanical dispersion was calculated as the standard deviation of the contraction duration of 17 strain segments. We assessed the associations between mechanical dispersion, concentrations of hs-cTnT and NT-proBNP, and cardiovascular risk factors collected at a national health screening survey two decades earlier. At echocardiography baseline, median age was 64 (interquartile range 63.5–64.5) years, 49.8% were women, 59.1% had hypertension, and 5.9% reported established coronary artery disease. Median mechanical dispersion was 38.0 (29.5–47.0) ms, median hs-cTnT concentration 6 (4–8) ng/L, and the median NT-proBNP concentration 54 (34–93) ng/L. Mechanical dispersion was associated with both hs-cTnT and NT-proBNP concentrations in multivariable models adjusted for clinical and echocardiographic variables. High body mass index, serum triglyceride concentrations, and low resting heart rate at Age 40 were independently associated with increased mechanical dispersion two decades later.ConclusionEstablished risk factors at Age 40 are associated with mechanical dispersion two decades later, and mechanical dispersion is cross-sectionally associated with biomarkers of subclinical myocardial injury and dysfunction.

Left Ventricular Strains and Myocardial Work in Adolescents With Anorexia Nervosa

BackgroundAnorexia nervosa (AN) is accompanied by bradycardia, low blood pressure (BP) and cardiac morphological remodeling. Systolic and diastolic functions are relatively preserved when assessed by standard ultrasound methods. However, novel advances based on speckle tracking echocardiography (STE), that could detect subtle and early alterations of left ventricular (LV) function, remained poorly used in AN patients.ObjectiveThe aim of this study was to assess the cardiac function of AN patients by evaluating LV myocardial strains, myocardial work (MW) and LV mechanical dispersion. We hypothesized that LV strains and global myocardial work would be decreased and LV twisting mechanisms enhanced to preserve the systolic function.MethodsFifty-nine adolescents including 26 women AN patients (14.6 ± 1.9 yrs. old) with a mean duration of AN of 19 ± 9 months and 33 controls (14.1 ± 2.0 yrs. old) underwent STE to assess LV morphology and myocardial regional strains.ResultsThe global longitudinal strain (GLS) was higher in AN patients compared to controls (−18.8 ± 2.0 vs. −16.9 ± 2.8%, p = 0.006). The area under the pressure-strain loop, representing the global MW was not altered but was shifted to the left and downwards in AN patients, due to their lower BP and higher GLS. Intraventricular mechanical dispersion was similar in both groups. Circumferential strains, twisting/untwisting mechanics were preserved.ConclusionOur results strongly support that the cardiac morphological remodeling observed in our AN patients was associated with normal ventricular regional myocardial functions. Only GLS was higher in AN patients, but its clinical significance remains to be demonstrated.

Echocardiographic predictors of ventricular arrhythmias in patients with non-ischemic cardiomyopathy.

ObjectiveVentricular arrhythmias (VA) portend a poor prognosis in non-ischemic cardiomyopathy (NICM). In this meta-analysis we evaluated if left ventricular (LV) global longitudinal strain (GLS) and LV mechanical dispersion (LVMD) are associated with VA, specifically in NICM patients.MethodsA systematic review and meta-analysis was performed to determine the predictive value of LV GLS and LVMD for VA in NICM patients. VA endpoints were a composite of sudden cardiac death, VA events (including ventricular tachycardia or ventricular fibrillation), cardiac arrest and appropriate implantable cardioverter-defibrillator (ICD) therapy. Hazard or odds ratios for univariate models were extracted for the relationship between LV GLS and LVMD with VA endpoints.ResultsA total of 984 patients from 6 published studies were included; 231 patients (23.5%) experienced the composite endpoint. NICM patients who experienced VA endpoints had LV GLS impairment compared to those without (weighted mean difference −1.93%; 95% confidence interval (CI) −2.77 to −1.10; p < 0.001) and LV GLS was related to VA endpoints (hazard ratio: 1.12, 95% CI 1.07–1.17, p < 0.001; odds ratio: 1.22, 95% CI 1.08–1.38, p = 0.002). Four studies reported mean LVMD (weighted mean −10.05 ms; 95% CI −28.25 to 8.14; p = 0.28), with 3 reporting risk ratios (1 reported odds ratio and 2 hazard ratios). Only odds ratio demonstrated statistical significance (hazard ratio: 0.47, 95% CI 0.01–22.25, p = 0.70; odds ratio: 1.59, 95% CI 1.14–2.22, p = 0.007).ConclusionLV GLS impairment demonstrates value for predicting VA endpoints in NICM patients. Inclusion of LV GLS may be appropriate in the surveillance, screening, and clinical management of NICM patients.

Pre-intervention left ventricular mechanical dispersion is increased in patients in need for pacemaker after TAVI

Abstract Funding Acknowledgements Type of funding sources: None. Background and Purpose Transcatheter Aortic Valve Implantation (TAVI) is an effective therapy for patients with severe aortic stenosis. Complete atrioventricular block (AVB) that requires permanent pacemaker treatment is a common complication of TAVI and it is reported in up to one fifth of patients. Prediction of this complication could be important. Global longitudinal strain (GLS) and left ventricular mechanical dispersion (LVMD) by speckle tracking echocardiography (STE) are novel techniques that detect subtle changes in myocardial function and are related to myocardial fibrosis. Thus, we aimed to investigate the association between LVMD and AVB development after TAVI. Methods We retrospectively screened 168 consecutive patients after TAVI. Patients with abnormal ECG and changed conduction pre- and post-TAVI were excluded. Data from the remaining 61 patients were compared to the group of 16 patients in need for a permanent pacemaker. Baseline echocardiograms recorded before TAVI were used to assess GLS and LVMD by STE (Figure). Results Of the 77 patients analysed, 60% were female (82 ± 7 years old). The mean GLS values were -16.8 ± 4.2% and -16.9 ± 3.7% in AVB and no AVB groups, respectively (p = 0.9). The mean LVMD was 60 ± 19 ms in AVB group and 50 ± 16 ms in no-AVB group (p = 0.04). (Table) Conclusion LVMD was increased in patients who developed TAVI-induced complete AVB, while GLS could not differentiate between post-procedural normal and abnormal electrical conduction. This finding may be important to identify myocardial properties associated with complete AVB after TAVI. Abstract Table Abstract Figure

Mechanical dispersion of left ventricle and left atrial reservoir strain are both superior to global longitudinal strain to predict exercise capacity in heart failure with preserved ejection fraction

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Fundação Adib Jatene Background/Introduction: Peak oxygen uptake (peak VO2) measures cardiovascular fitness and is a valuable diagnostic and prognostic marker in patients with heart failure with preserved ejection fraction (HFpEF). Measurement of peak VO2, however, requires specialized equipment and expert supervision, limiting its routine use by practicing clinicians. Strain curves obtained by speckle tracking echocardiography (STE) can provide different parameters of myocardial mechanics such as the Global Longitudinal Strain (GLS), which is the most robust STE feature for clinical practice. Notwithstanding, there is conflicting data on whether the GLS is associated with peak VO2 in HFpEF subjects. Moreover, few studies have addressed the relationship between peak VO2 and other interesting deformation parameters such as the left atrial (LA) reservoir strain or the left ventricular mechanical dispersion (MD). Purpose The present study aimed to examine the utility of the myocardial mechanics as assessed by STE in predicting peak VO2 in patients with HFpEF. Methods From an ongoing prospective cohort of 189 subjects, we sampled subjects with different HFpEF stages. All patients underwent cardiopulmonary exercise testing (CPX) and a 2D-STE (LV GLS, MD, LA reservoir strain, LA conduit strain, and LA contraction strain) obtained by a blinded examinator. The missing data was handled by complete case analysis approach. We excluded subjects who had atrial fibrillation/flutter, severe COPD, STE with poor tracking quality, CPX with respiratory exchange rate (RER) &amp;lt; 1. The Spearman"s correlation was calculated, and the 95% CI were estimated. Finally, an estimative of the STE features importance to predict peak VO2 &amp;lt; 20mL/Kg/min was done using the function "xgb.importance()" from machine learning model XGBoost in R software. XGBoost is a variant of Gradient Boosting Method that uses ensembles of decision trees. Results We obtained 74 subjects (23 without evidence of heart disease, 23 with pre-heart failure and 28 with HFpEF). The MD presented the highest correlation with peak VO2 (Rho=-0.48; p-value &amp;lt; 0.001) followed by LA reservoir strain (Rho = 0.40; p-value &amp;lt; 0.001), LA conduit strain (Rho= –0.36; p-value &amp;lt; 0.001) and LA contraction (Rho= –0.30 p-value &amp;lt; 0.004) as shown in Figure 1. However, no correlation was found between GLS and peak VO2 (Rho= –0.07 p-value &amp;lt; 0.5) (Figure 2A). The feature importance score (Figure 2B) showed the MD as the best relative contribution for VO2 prediction (gain= 0.34) superior to LA reservoir strain (gain = 0.25). GLS presented contribution (gain = 20) superior to LA conduit strain (gain =10) and LA contraction strain (gain = 0.08). Conclusion Left ventricular mechanical dispersion and left atrial reservoir strain obtained with STE were better predictors of peak VO2 than GLS in patients with different HFpEF stages and may be helpful in risk stratification and diagnosis. Abstract Figure 1 Abstract Figure 2

Exercise-Induced Cardiac Fatigue in Soldiers Assessed by Echocardiography.

Background: Echocardiographic signs of exercise-induced cardiac fatigue (EICF) have been described after strenuous endurance exercise. Nevertheless, few data are available on the effects of repeated strenuous exercise, especially when associated with other constraints as sleep deprivation or mental stress which occur during military selection boot camps. Furthermore, we aimed to study the influence of experience and training level on potential EICF signs.Methods: Two groups of trained soldiers were included, elite soldiers from the French Navy Special Forces (elite; n = 20) and non-elite officer cadets from a French military academy (non-elite; n = 38). All underwent echocardiography before and immediately after exposure to several days of uninterrupted intense exercise during their selection boot camps. Changes in myocardial morphology and function of the 4 cardiac chambers were assessed.Results: Exercise-induced decrease in right and left atrial and ventricular functions were demonstrated with 2D-strain parameters in both groups. Indeed, both atrial reservoir strain, RV and LV longitudinal strain and LV global constructive work were altered. Increase in LV mechanical dispersion assessed by 2D-strain and alteration of conventional parameters of diastolic function (increase in E/e' and decrease in e') were solely observed in the non-elite group. Conventional parameters of LV and RV systolic function (LVEF, RVFAC, TAPSE, s mitral, and tricuspid waves) were not modified.Conclusions: Alterations of myocardial functions are observed in soldiers after uninterrupted prolonged intense exercise performed during selection boot camps. These alterations occur both in elite and non-elite soldiers. 2D-strain is more sensitive to detect EICF than conventional echocardiographic parameters.

Impact of inter-vendor variability on evaluation of left ventricular mechanical dispersion.

Left ventricular mechanical dispersion (LVMD) is a novel speckle tracking parameter for prognostic assessment of arrhythmic risk prediction. There is growing evidence to support its use in a variety of cardiomyopathic processes. There is paucity of data addressing any presence of inter-vendor discrepancies for LVMD. The aim of this study was to assess inter-vendor variability of LVMD in vendor specific software (VSS) and vendor independent software (VIS) in subjects with preserved and reduced left ventricular function. Fifty-nine subjects (14 normal subjects and 45 subjects with cardiac disease) were recruited and 2D speckle tracking echocardiographic images were acquired on two different ultrasound machines (GE and Philips). LVMD was measured by two different VSS (EchoPac GE and QLAB Philips) and one VIS (TomTec Arena). There was significant bias and wide limits of agreement (LOA) in the overall cohort observed between two different VSS (17.6ms; LOA: -29.6 to 64.8; r: .47). There was acceptable bias and narrower LOA with good agreement for LVMD between images obtained on different vendors when performed on VIS (-3.1ms; LOA: -27.6 to 21.4; r: .75). QLAB LVMD was consistently higher than GE LVMD and TomTec LVMD in both preserved and reduced left ventricular function. LVMD measurements have high intra-vendor reproducibility with excellent inter and intra-observer agreement. There was acceptable bias and narrower LOA for LVMD assessment on a VIS. Inter-vendor variability exists for LVMD assessment between VSS. Serial measurements of LVMD should be performed using a single vendor for consistent and reliable results.

Ventricular arrhythmia susceptibility in a new porcine model of heart failure (HF) with reduced ejection fraction

Abstract Introduction Sudden death secondary to ventricular arrhythmias is common in HF patients, with no effective treatment available outside of implantable cardiac defibrillators. While animal models are essential for the discovery of anti-arrhythmic drugs, no reliable large animal HF models with associated ventricular arrhythmias have been described so far. Objectives We aimed at evaluating ventricular remodeling and arrhythmia susceptibility in an HF pig model with reduced ejection fraction (EF) following myocardial infarction (MI). Methods MI was induced in 53 male Göttingen minipigs (12–15 months, 20–25 kg) by coronary embolization in mid-left anterior descending and mid-left circumflex coronary arteries using endovascular coils. Seven other pigs underwent sham operation and were used as control. Two weeks after surgery, cardiac function was assessed by echocardiography, and animals were included based on EF&amp;lt;50% (n=15/53), assigned either to 12 weeks of vehicle (n=9) or perindopril (n=6, 1 mg/kg/d, per os) group. At the end of the study, their left ventricular (LV) electrical remodeling was studied by echocardiography/electrocardiography and a programmed-electrical stimulation protocol was performed to evaluate the susceptibility to develop ventricular arrhythmias. Results At the end of the study, animals in the vehicle group had a significant LV remodeling associated with a reduced EF (p&amp;lt;0.05 vs. sham, see table). This remodeling was associated with cardio-pulmonary congestion, significant increases in LV end-diastolic pressure, left atrial volume, and lung mass (all p&amp;lt;0.05 vs. sham, see table), fully prevented by perindopril treatment. They had also an electrical remodeling as evidenced by an increase in PR, QRS, and QTc intervals, as well as LV effective refractory period (+18%, 14%, 33%, and 13%, respectively, p&amp;lt;0.05, compared to sham animals). Electrical changes were mitigated by perindopril treatment (p=NS vs. sham). LV mechanical dispersion measured with speckle-tracking echocardiography was significantly increased in vehicle group (58±5 vs. 22±1 ms in sham group, respectively) as well as in perindopril group. Programmed-electrical stimulations induced in 6/8 vehicle animals either non-sustained (n=3) or sustained (n=2) ventricular tachycardia, or ventricular fibrillation (n=1). In sham group only 1/7 animal had a ventricular fibrillation. No inducible ventricular arrhythmia was observed in animals treated with Perindopril. Conclusion In this new pig model of congestive HF with reduced EF, LV remodeling was associated with electrical remodeling and susceptibility to develop arrhythmias. Chronic angiotensin-converting enzyme inhibitor treatment prevented congestion, mitigated electrical remodeling, and suppressed arrhythmia susceptibility. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Servier Research Institute - CardioVascular &amp; Metabolic Diseases Center for Therapeutic Innovation Table 1

Optimal echocardiographic assessment of myocardial dysfunction for arrhythmic risk stratification in phospholamban mutation carriers.

Aims Phospholamban (PLN) p.Arg14del mutation carriers are at risk of developing malignant ventricular arrhythmias (VAs) and/or heart failure. Currently, left ventricular ejection fraction (LVEF) plays an important role in risk assessment for VA in these individuals. We aimed to study the incremental prognostic value of left ventricular mechanical dispersion (LVMD) by echocardiographic deformation imaging for prediction of sustained VA in PLN p.Arg14del mutation carriers.Methods and resultsWe included 243 PLN p.Arg14del mutation carriers, which were classified into three groups according to the ‘45/45’ rule: (i) normal left ventricular (LV) function, defined as preserved LVEF ≥45% with normal LVMD ≤45 ms (n = 139), (ii) mechanical LV dysfunction, defined as preserved LVEF ≥45% with abnormal LVMD >45 ms (n = 63), and (iii) overt LV dysfunction, defined as reduced LVEF <45% (n = 41). During a median follow-up of 3.3 (interquartile range 1.8–6.0) years, sustained VA occurred in 35 individuals. The negative predictive value of having normal LV function at baseline was 99% [95% confidence interval (CI): 92–100%] for developing sustained VA. The positive predictive value of mechanical LV dysfunction was 20% (95% CI: 15–27%). Mechanical LV dysfunction was an independent predictor of sustained VA in multivariable analysis [hazard ratio adjusted for VA history: 20.48 (95% CI: 2.57–162.84)].Conclusion LVMD has incremental prognostic value on top of LVEF in PLN p.Arg14del mutation carriers, particularly in those with preserved LVEF. The ‘45/45’ rule is a practical approach to echocardiographic risk stratification in this challenging group of patients. This approach may also have added value in other diseases where LVEF deterioration is a relative late marker of myocardial dysfunction.