Left Ventricular Free Wall Research Articles

Assessment of cardiac structure and function 1.5 years after COVID-19: results from the EPILOC study

Abstract Background Impaired left and right ventricular function have been observed mainly in hospitalized patients with acute SARS-CoV-2 infection. The long-term cardiac sequelae have not yet been conclusively clarified in large, well-defined cohorts. In addition, it is not yet certain whether cardiac function is related to persistent cardiopulmonary symptoms or reduced exercise capacity after COVID-19. Purpose Differences in cardiac structure and function in patients with suspected post-COVID syndrome (PCS) and in recovered control patients (CON) were analysed with regard to the association with cardiopulmonary symptoms and physical performance. Methods In this multicentre study, transthoracic echocardiography was performed in 1154 individuals (49±12 years, 760 women) 1.5 years after SARS-CoV-2 infection (October 2020 till April 2021) in southwest Germany. Left and right ventricular global longitudinal strain (LV/RV GLS) and RV free wall strain (FWS) were determined with post-processing software in 679 PCS and 475 CON. Cardiopulmonary exercise testing (CPET) was performed with a ramp protocol on a bicycle ergometer. Results PCS showed lower LV GLS (-20.25% vs. -20.73%, p=0.003), diastolic function (E/A 1.16 vs. 1.21, p=0.022) and TAPSE (24.45 vs. 25.05, p=0.022) compared to CON, while RV strain values did not differ. Echocardiographic parameters were within the normal clinical reference range. LV GLS was negatively associated with VO2max (p=0.004) and positively associated with rapid physical exhaustion (p=0.050), but not with cardiopulmonary symptoms. Conclusions Significantly reduced cardiac function in PCS compared to CON 1.5 years after SARS-CoV-2 infection could indicate long-term left myocardium involvement, while signs of RV involvement were inconsistent. The differences between the groups appear to be small and could be explained by deconditioning due to PCS or the more frequent presence of cardiovascular disease in PCS. Nevertheless, it cannot be ruled out that a slight reduction in cardiac function and physical performance could be a long-term consequence of COVID-19 in patients with persistent symptoms. Further (long-term) studies are therefore necessary to investigate the connection between persistent exercise intolerance and cardiac involvement. This could lead to further diagnostic steps and therapy recommendations.

Echocardiographic Changes Following Surgical Myectomy in Severely Symptomatic Obstructive Hypertrophic Cardiomyopathy: Insights From the SPIRIT-HCM Study.

In obstructive hypertrophic cardiomyopathy, myectomy improves symptoms, quality of life, and left ventricular (LV) outflow tract gradients. We prospectively evaluated the temporal changes in various echo parameters after myectomy. In 173 adults with obstructive hypertrophic cardiomyopathy (53±10 years, 63% men) who underwent myectomy between March 2017 and June 2020, clinical and blinded echo assessment (before and at 12±6 months follow-up) was performed prospectively (SPIRIT-HCM [Quality of Life and Functional Capacity Following Septal Myectomy in Obstructive Patients With Hypertrophic Cardiomyopathy]). Changes in echocardiographic parameters (left atrial volume index, E/e', LV outflow tract gradients, along with average LV global longitudinal strain on apical 2-, 3-, and 4-chamber views and regional LV strain from apical 4-chamber view) were measured in 126 patients. There was significant improvement in left atrial volume index (-6.9 mL/m2 [95% CI, 4-9.7]), E/e' (-2.9 [95% CI, -2.7 to -4.1]) and peak LV outflow tract gradient (-94 mm Hg [95% CI -87 to -100]) from baseline to follow-up (both P<0.001). There was no improvement in basal (0.91% [95% CI, -0.15 to 1.97], P=0.09) and midseptal (-0.98% [95% CI, -1.93 to 0.02], P=0.05) LV strain, worsening in apical septal strain (-4.5% [95% CI, -5.9 to -3.0], P<0.001) and an improvement in LV free wall strain (2.3% [95% CI, 0.67-3.9], P<0.001), with no change in overall LV-global longitudinal strain (0.47% [95% CI, -0.43 to 1.37], P=0.30). There was no correlation between change in LV-global longitudinal strain and change in 6-minute walk time (r=0.12, P=0.24) or Kansas City Cardiomyopathy Questionnaire summary score change (r=0.02, P=0.85), whereas it was significantly associated with change in E/e' (r=0.29, P=0.003). In patients with obstructive hypertrophic cardiomyopathy, myectomy improved various echocardiography parameters at 1-year; however, LV-global longitudinal strain remained unchanged. URL: https://clinicaltrials.gov; Unique identifier: NCT03092843.

Clustering regional patterns of left ventricular longitudinal strain in systemic sclerosis-related pulmonary hypertension.

Systemic sclerosis-related pulmonary hypertension (SSc-PH) is a heterogeneous disease, often complicated by concomitant left ventricular (LV) dysfunction. However, the contribution of heterogeneity in LV dysfunction is unclear. The objective in this study was to identify regional clusters of LV longitudinal strain via echocardiography to determine how subgroups of LV dysfunction contribute to mortality in SSc-PH. We performed a retrospective observational study on 124 patients with SSc-PH in which LV longitudinal strain was collected over a 16-segment model. We applied K-means clustering to LV longitudinal strain at each segment using the Calinski-Harabasz index. Our primary outcome was time to all-cause mortality. Patients with SSc-PH were divided into two clusters (Cluster 1: N=59; Cluster 2: N=65). The most pronounced differences in longitudinal strain between each cluster were observed at the basal and mid segments, particularly at the interventricular septum. In comparison to Cluster 1, Cluster 2 was characterized by both regional and global reductions in LV and right ventricular (RV) free wall longitudinal strain, greater PH severity, and greater functional limitation by New York Heart Association with a hazard ratio of 2.06 (95% CI: 1.21, 3.50) for all-cause mortality. Using K-means clustering of regional patterns of LV longitudinal strain, we identified a distinct phenotype of patients at increased risk for mortality. Most of the pronounced differences in longitudinal strain between each cluster were observed at the basal and mid segments, particularly at the interventricular septum.

Two-dimensional, m-mode and doppler-derived echocardiographic parameters in standing healthy dorper sheep

Sheep are widely used in cardiovascular system research with emphasis in translational research for the echocardiographic diagnosis of heart diseases. Several studies have proposed reference values for the various echocardiographic parameters in healthy sheep. It is known that breed, age, sex and the technique used can contribute to changes in echocardiographic parameters, the reason for investigations in Dorper sheep echocardiography. The aim of study was to establish reference two-dimensional, m-mode and Doppler-derived echocardiographic parameters in standing Dorper sheep and to determine whether there is an influence of sex on echocardiographic parameters. Sixty-five pure Dorper lambs with 3–5 months of age, weighing 29.47 ± 3.1 kg were used. The Doppler echocardiographic was conducted in a standing position through right parasternal windows for the long axis of the left ventricular outflow tract, short axis at the level of the papillary muscles, mitral valve, aortic valve, and left atrium; and left parasternal for the cranial long axis of the right ventricular outflow tract. Significant differences between males and females were noted in left ventricular free wall (LVFW) measurements during diastole (P = 0.03) and systole (P = 0.04), as well as in output by pulmonary artery flow (DCPA) values (P = 0.03). This study successfully established Doppler echocardiographic reference values for cardiac dimensions, left ventricular systolic function, and pulmonary artery flow in healthy lamb Dorper in a standing position.

Abstract 4117690: Cardiac Rupture as a Life-Threatening Outcome of Takotsubo Syndrome: A Systematic Review.

Background: Takotsubo syndrome is a reversible cause of heart failure; however, a low percentage of patients can develop serious complications, including cardiac rupture. Aims: Analyze case reports or case series of cardiac rupture in patients with Takotsubo syndrome, detailing patient characteristics to uncover risk factors and prognosis for this severe complication. Methods: We conducted a systematic search of MEDLINE and Embase databases to identify case reports or case series of patients with Takotsubo syndrome complicated by cardiac rupture, from inception to October 2023. Results: We identified 39 reported cases, including 44 subjects (40 females; 4 males) with a median age of 75 (IQR 71-82) years, of White/Caucasian (61%) or East Asian/Japanese (39%) ethnicity. An emotional trigger was present in 15 (34%) subjects and common admission symptoms were chest pain (35 [80%]) and dyspnea (14 [32%]). ST-segment elevation was present in 39 (93%) of 42 cases, with the anterior myocardial segments (37 [88%]) being the most compromised, followed by lateral (26 [62%]) and inferior (14 [33%]) segments. The mean left ventricular ejection fraction was 40±13% and an apical ballooning pattern was observed in all (100%) ventriculographies. The median time to cardiac rupture was 48 (5-120) hours since admission, with the left ventricular free wall (25 [57%]) being the most frequent site of perforation. Surgery treatment was attempted in 16 (36%) cases, and 28 (64%) patients did not survive (Figure). Conclusions: Cardiac rupture as a complication of Takotsubo syndrome is a rare clinical condition associated with high mortality. Elderly females, especially from White/Caucasian or East Asian/Japanese descent, presenting with ST-segment elevation in the anterior or lateral leads, and an apical ballooning pattern, are disproportionally affected. Additional studies with prospective collection of patient-level data are needed to better identify those at increased risk for cardiac rupture associated with Takotsubo syndrome and to address ways to improve mortality rates in this population.

Novel Agonists of Adenosine Receptors in Animal Model of Acute Myocardial Infarction.

Current treatments for acute myocardial infarction (AMI) include pain relief and attempts to improve survival. This study investigated the effects of two new ligands of the adenosine receptor, LASSBio-1027 and LASSBio-1860, on cardiac function in an experimental model of AMI. AMI was induced in Wistar rats by ligating the anterior descending coronary arteries. Infarcted animals were treated orally with vehicle (DMSO), LASSBio-1027 (30 and 70μmol/kg), or LASSBio-1860 (70μmol/kg) for seven days. Hemodynamic parameters were observed using echocardiography, whereas inflammation and fibrosis were detected using histological analysis. MI increased the filling pressure from 23.0 ± 1.6 and 14.0 ± 2.0 to 37.0 ± 3.7 and 33.2 ± 8.0, respectively indicating diastolic dysfunction. However, treatment with LASSBio-1027 (70μmol/kg) and LASSBio-1860 (70μmol/kg) reduced this parameter to 23.9 ± 5.4 and 17.1 ± 6.7. An impairment in ejection fraction from 57.1 ± 3.2 to 36.6 ± 2.0% was observed after MI, partially recovered to 47.0 ± 7.4% by LASSBio-1027 and fully restored to 61.8 ± 4.3% after 7 days of treatment with LASSBio-1860. After MI, collagen deposition in LV free wall was increased to 31.4 ± 11.0% and treatment with LASSBio-1027 reduced to 23.4 ± 6.0 and 19.7 ± 8.0% at 30 and 70μmol/kg, respectively. Similarly, LASSBio-1860 reduced collagen levels to 63.1 ± 2.0%. Fibrosis and inflammatory components of MI reduced following treatment with agonist of adenosine receptor subtype A2A. Cardiac remodeling induced by LASSBio-1027 and LASSBio-1860 may be responsible for the improvement in cardiac function in AMI through the activation of A2A adenosine receptors.

Improving exercise cardiac reserve assessment using a novel cardiopulmonary and echocardiography testing protocol (CPET-ESE) based on individualised exercise intensity domains

Abstract Background Functional exercise stress echocardiography (ESE) is used to quantify changes in cardiac reserve and can improve early cardiac dysfunction diagnosis and follow-up.[1.2] Current ESE protocols do not account for individual variations in fitness and heart rate response, leading to difficulties in defining normal reference values.[2,3] Physiologically defined exercise intensity domains could be implemented as part of combined cardiopulmonary and ESE testing (CPET-ESE) to address this problem. Purpose We propose that using exercise intensity domains as part of CPET-ESE will result in cardiac reserve values not influenced by individual cardiorespiratory fitness or physical activity (PA) levels. We also hypothesise by matching work-rates and heart rates (HR), respectively, cardiac reserve will be higher in those exercising at the higher exercise intensity domain. Methods A total of 45 healthy adults (mean age 43.8 ± 14.2, range 18-65 y) underwent a CPET followed by a CPET-ESE consisting of two 6-minute stages: 1. Moderate intensity (MOD) at 90% of the work-rate at the gas exchange threshold (GET) and 2. High intensity (HIGH) at 40% of the difference between GET and peak. Global left ventricular and right ventricular free wall (LV and RV) longitudinal strain (Sl), RV fractional area change (RV-FAC), peak LV and RV TDI derived systolic (S’) and diastolic velocities (E’) were measured at each step, including rest. HIGH steps were matched 1-to-n with MOD steps from other participants based on work-rate and HR, respectively. Questionnaire derived PA was classified as low, moderate, and high active. Cardiorespiratory fitness was measured as peak oxygen uptake relative to body mass (mL·kg-1·min-1). Results After adjusting for age and sex, neither higher PA nor peak VO2 were associated with higher cardiac function parameters at either intensity (Table 1). Higher peak VO2 was associated with higher work-rate for HIGH only, while higher PA was associated with lower HR for MOD only (interaction term p&amp;lt;0.05). When paired by matching HR and work-rate, respectively, HIGH was associated with higher cardiac function parameters compared to MOD (all except for LV-S’ and RV-FAC when HR matched, Table 2), despite those matched from HIGH being older, less physically active and having lower peak VO2 (p&amp;lt;0.05 for all). Conclusions Current ESE protocols, which define submaximal exercise intensity using arbitrary work-rate or HR targets,[3] do not account for the complex differences in exercise response between healthy individuals. Cardiac function augmentation during exercise is likely a response to VO2 kinetics and this is not accurately described by either HR or work-rate alone. We derived normal reference values for cardiac reserve from implementing physiologically defined exercise intensity domains within the combined CPET-ESE testing frameworks. These values could be more appropriately used when comparing diverse clinical populations using CPET-ESE.

A simple and reliable computed tomographic measure for the evaluation of right ventricle remodelling in acute PE: right ventricle apical angle

Abstract Background and aims In patients with acute pulmonary embolism (PE), right ventricular (RV) dysfunction as assessed by computed tomography (CT) and /or echocardiography has been considered to predict in-hospital and 30-day outcomes. In this study we proposed a novel CT measure for RV function, the apical angle (α1) between the RV free wall and the interventricular septum (IVS), and for the left ventricle (LV) function, the apical angle (α2) between the LV free wall and the IVS. We aimed to evaluate the predictive value of these angles to determine clinical and hemodynamic severity and in-hospital mortality (IHM) in acute PE patients. Methods The study population comprised retrospectively evaluated 536 patients (age 59+-16.2 years, female 55.3 %) with acute PE in whom diagnostic work-up and risk-based treatments have been performed in accordance with currently available acute PE Guidelines. The severity of pulmonary arterial (PA) obstruction (Qanadli score) and RV/LV ratio were assessed on CT, and RV function and non-invasive estimation of pulmonary arterial systolic pressures (PASP) were evaluted with echocardiography. The α1 was defined as the angle between the line from tricuspid medial annulus to the RV apex and second line from tricuspid lateral annulus to the RV apex, whereas α2 was defined as the angle between the line from mitral medial annulus to the LV apex and second line from mitral lateral annulus to the LV apex. Results Anticoagulant treatment only and intravenous tissue plasminogen activator were noted in 49.6 % and 17.9 % of patients, respectively. Ultrasound-assisted thrombolysis and rheolytic thrombectomy were also used in 25% and 7.5 % of patients, respectively. The IHM rate was 5.9 %. The increase in α1 was associated with a decrease in TAPSE/PASP ratio, and an increase in PESI score and a higher risk status (p=0.047, p&amp;lt;0.001, p=0.001 respectively), but α2 showed no relation to PE severity (p=0.78). The value of α1 in predicting in-hospital mortality was evaluated with a logistic regression analysis with a model including PESI score, RV/LV ratio and α1. PESI score and α1 significantly predicted IHM (p= &amp;lt;0.001 and 0.027, respectively. OR for a1 1.15, CI 95%[1.06-1.27]), but RV/LV ratio did not. In the receiver operating curve (ROC) analysis for IHM prediction, the cut-off value of 1.168 for α1/α2 ratio [area under the curve (AUC): 0.721; sensitivity:76.92 % and specificity: 65.8 %] and the cut-off value of 32.47 for α1 ( AUC: 0.718 ; sensitivity: 84.67 % and specificity: 59.5 %) provided higher prediction compared with cut-off value of 1.29 for RV/LV ratio ( AUC : 0.604 ; sensitivity 76.9 % and specificity 45.87 %). Conclusion Either α1 or α1/α2 ratio evaluation on CT seems to represent a simple and reliable approach in the assessment of RV acute remodelling in response to thrombo-obstructive pressure burden and for prediction of outcome in patients with acute PE.Alpha 1 angle of different risk groupsROC curve

Left ventricular hypertrophy, wall thickness, and histological myocyte alteration in end-stage heart failure: a call for a standard definition

Abstract Objective This study aimed to examine the relationship between different left ventricular hypertrophy (LVH) classification criteria according to the American Society of Echocardiography (ASE), and anatomical measurement of LV wall thickness (LVWT) and histological evidence of myocyte hypertrophy. Methods Data from 146 consecutive patients (47 years; 75% were male) who have undergone heart transplantation were analysed. Fixed ventricles were dissected and measured in weight after both atria, great vessels, and epicardial fat were removed. The fixed biventricular weight was calculated as 87% of total weight (the effect of fixed formalin reduced the total weight by 3%). Anatomical LVWT was measured with a ruler at LV free wall where maximal thickness is located. A comprehensive echocardiogram was performed in all patients before heart transplantation. LVM and relative wall thickness (RWT) (2 PWT/LVEDD) were measured by M-mode echocardiography in parasternal long-axis view. Patients were considered to have LVH when the LVM index exceeds 95 g/m2 in women and exceeds 115 g/m2 in men. Patients were considered to have concentric LVH when RWT &amp;gt; 0.42. LVWT was measured using 2D echocardiography perpendicular to the LV long axis. Results Of 146 explanted hearts, dilated cardiomyopathy (CM), cardiac amyloid, and hypertrophic CM were diagnosed in 53 (47%), 1 (1%), and 8 (5%) patients, respectively. Anatomic ventricular mass correlated with echocardiographic LVM (r=0.5, p &amp;lt; 0.01). Anatomic LVWT modestly correlated with echocardiographic LVWT (r=0.2, p=0.01). Of 146 patients, echocardiographic normal LV geometry, concentric LV remodelling, concentric LVH, and eccentric LVH were present in 22 (15%), 6 (4%), 14 (10%), and 104 (71%), respectively. Increased LVWT (≥ 13 mm) assessed by 2-D echocardiography was present in normal LV geometry (5%), concentric LV remodelling (5%), concentric LVH (57%), and eccentric LVH (33%) (p &amp;lt;0.001) in those classified by ASE guidelines. Anatomic LVWT (≥ 13 mm) was present in normal LV geometry (14%), concentric LV remodelling 5%), concentric LVH (14%), and eccentric LVH (80%) (p &amp;lt;0.001) in those classified by ASE guidelines. Histological myocyte hypertrophy was present in normal LV geometry (12%), concentric LV remodelling (2%), concentric LVH (11%), and eccentric LVH (70%) (p &amp;lt;0.001) in those classified by ASE guidelines. Conclusions 2D-derived echocardiographic increased LVWT in patients with LVH defined by increased LVM index was present in approximately 30-50%. Furthermore, anatomical increased LVWT in those with LVH classified by ASE guidelines was present in a varying range of 10-70%. Patients with concentric LVH had a low prevalence of histological myocyte hypertrophy (approximately 10%). Inconsistencies in classification methods reveal the need for more robust LVH terminologies and definition that is consistent across cardiac imaging and anatomico-pathological examination, particularly in patients with CM.

Incremental value of biventricular strain in patients with severe aortic stenosis

Abstract Background Left ventricular global longitudinal (LVGLS) and right ventricular free wall strain (RVFWS) demonstrated separately prognostic value in patients with severe aortic stenosis (AS). However, studies evaluating combined assessment of LVGLS and RVFWS have shown contradictory results. Aim To explore the prognostic value of combining LVGLS and RVFWS in a large group of severe AS patients referred for transcatheter aortic valve implantation. Methods Patients were classified into three groups: preserved (LVGLS ≥15% AND RVFWS &amp;gt;20%), single-ventricle impaired (LVGLS &amp;lt;15% OR RVFWS ≤20%), or biventricular impaired strain group (LVGLS &amp;lt;15% AND RVFWS ≤20%). Cut-off values were based on previously published data and spline analyses. Endpoint was all-cause mortality. Results Of the 712 patients included (age 80±7 years, 53% men), 248 (35%) died. The single-ventricle impaired and biventricular impaired (vs. preserved) strain groups showed significantly lower 5-year survival rates (68%and 55%vs.77%, respectively, p&amp;lt;0.001; Figure 1). On multivariable analysis, single-ventricle impaired (HR 1.762; 95%CI:1.114-2.788; p=0.015) and biventricular impaired strain groups (HR1.920; 95%CI:1.134-3.250; p=0.015) were independently associated with all-cause mortality. These findings were confirmed by sensitivity analysis in patients with preserved LV ejection fraction (Figure 2). Conclusions In patients with severe AS, biventricular strain allows better risk stratification, even if LV ejection fraction is preserved.

Association of Coronary Microvascular Rarefaction and Myocardial Fibrosis With Coronary Artery Disease.

To evaluate, in a cohort study, whether coronary microvasculature and myocardial structure differ between people with and without coronary artery disease (CAD). We performed histological analysis of left ventricle free wall obtained at autopsy from 25 men and 23 women with ≥1 coronary artery with ≥75% area stenosis, and 25 men and 25 women without (no or minimal) CAD, matched for sex and age, who died suddenly from noncardiac causes. Decedents with myocardial infarction or other cardiac abnormality were excluded. Decedents with and without CAD had similar height and weight. Heart weight of decedents with CAD was higher than that of decedents without CAD (mean, 391 versus 364 g; mean difference, 27 g [95% CI, 0.3-54.0], P=0.048). Decedents with CAD had lower arteriole density (mean, 1.4 per mm2 versus 1.8 per mm2; mean difference, -0.4 per mm2 [95% CI, -0.6 to -0.2], P=0.0001), lower capillary length density (mean, 3164 versus 3701 mm/mm3; mean difference, -537 [95% CI, -787 to -286], P<0.0001), and higher total myocardial fibrosis (mean, 7.5% versus 5.7%; mean difference, 1.7% [95% CI, 1.0-2.5], P<0.0001), than decedents without CAD. CAD was associated with coronary microvascular rarefaction and increased myocardial fibrosis. The association of CAD with coronary microvascular rarefaction and increased myocardial fibrosis may contribute to the increased risks of death, myocardial infarction and heart failure that accompany CAD, and may attenuate the impact of percutaneous coronary intervention on cardiovascular risk in people with stable angina.

Echocardiographic Quantitation of Left Ventricular Size and Function in Indian Mongrel Dogs

Background: No published data on two-dimensional echocardiographic quantitation of left ventricular size and function in Indian mongrel dogs is reported till date. Methods: Reference intervals for linear and area measurements of left ventricle size and function was generated in fifty healthy mongrel dogs (25 males, 25 females; mean age=1.59±0.13 yr; mean body weight=16.66±0.73 kg) using two-dimensional echocardiography. Dogs deemed healthy after thorough clinico-physiological, hematological, radiographic, electrocardiographic and echocardiographic evaluation were included in study.Relationship between two-dimensional linear and area measurements of left ventricle and body weight and, between same measurements obtained from different tomographic planes was studied using linear regression analysis. Result: Linear left ventricular measurements, left ventricular internal and external area, mitral valve orifice area showed significant (P less than 0.001) positive correlation with body weight while fractional shortening and ejection fraction showed significant (P less than 0.001) weak negative correlation with body weight. Left ventricular internal length in diastole, interventricular septum thickness and left ventricular internal dimension in systole and left ventricular free wall thickness in diastole were significantly (P less than 0.01) higher in male dogs while mitral valve orifice area was significantly (P less than 0.01) higher in female dogs. All linear measurements of left ventricular size obtained from different tomographic planes displayed significant (P less than 0.001) correlation with each other.

Euterpe Oleracea Martius (Açaí) Extract and Resistance Exercise Modulate Cardiac Parameters of Hypertensive Rats.

The study evaluated the effects of resistance exercise training and açaí supplementation on cardiac parameters in hypertensive animals. For this study, rats from the Wistar and SHR lines (spontaneously hypertensive rats) were used. The animals were divided into 5 groups: Wistar Control (C); Control Hypertensive (H); Trained Hypertensive (HT); Hypertensive and Supplemented with Açaí (HA); and Hypertensive Trained and Supplemented with Açaí (HAT). Resistance exercise training was carried out through climbing. The supplemented groups received 3 g of açaí/kg of body mass. The animals' systolic blood pressure (SBP), body mass, and physical test were measured at the beginning and end of the intervention. At the end, an echocardiographic analysis was performed. Histological analysis and oxidative stress of the LV were performed. It was found that hypertensive animals showed an increase in SBP, and the treatments reduced this parameter. The trained groups achieved higher values of maximum carrying load. Hypertension increased the dimension of the left ventricular free wall in diastole and reduced ejection and shortening fractions. The trained groups showed improvement in ejection and shortening fractions. The H group increased the proportion of extracellular matrix and reduced the proportion of cells, with the HAT group attenuating this change. Cell diameter was greater in group H, and all treatments reduced this parameter. Hypertension increased the concentration of malondialdehyde and decreased catalase activity in LV. The treatments managed to mitigate this damage. It is concluded that the treatments managed to generate positive cardiovascular adaptations, and their combination enhanced these effects.

Left Ventricular Perforation Following Transcutaneous Pigtail Catheter Placement Mimicking Anterior Wall Myocardial Infarction: An Unusual Complication.

In modern medical practice, procedures that involve the use of catheters are common. These procedures can range from percutaneous coronary and peripheral vascular interventions to using catheters to drain fluid. However, complications associated with catheter usage can arise, and the most severe one is the puncture of a vital organ due to catheter misplacement. In this case, we present a rare complication related to the use of a pigtail catheter, which caused perforation of the left ventricular free wall. The patient presented with an electrocardiogram showing ST segment elevation in the anterior wall, indicative of a heart attack. The patient underwent coronary angiography, which showed that the coronary arteries were unblocked. However, during the procedure, the medical team suspected that the pigtail catheter was stuck in the left ventricle chamber, based on the use of fluoroscopy. This suspicion was later confirmed using computer tomography. To address the issue, the patient underwent an emergent cardiorrhaphy, which was performed immediately. Fortunately, the patient survived the complication.

A comprehensive experimental analysis of the local passive response across the healthy porcine left ventricle

This work provides a comprehensive characterization of porcine myocardial tissue, combining true biaxial (TBx), simple triaxial shear (STS) and confined compression (CC) tests to analyze its elastic behavior under cyclic loads. We expanded this study to different zones of the ventricular free wall, providing insights into the local behavior along the longitudinal and radial coordinates. The aging impact was also assessed by comparing two age groups (4 and 8 months). Resulting data showed that the myocardium exhibits a highly nonlinear hyperelastic and incompressible behavior. We observed an anisotropy ratio of 2-2.4 between averaged peak stresses in TBx tests and 1-0.59-0.40 orthotropy ratios for normalised fiber-sheet-normal peak stresses in STS tests. We obtained a highly incompressible response, reaching volumetric pressures of 2-7 MPa for perfused tissue in CC tests, with notable differences when fluid drainage was allowed, suggesting a high permeability. Regional analysis showed reduced stiffness and anisotropy (20-25%) at the apical region compared to the medial, which we attributed to differences in the fiber field dispersion. Compressibility also increased towards the epicardium and apical regions. Regarding age-related variations, 8-month animals showed stiffer response (at least 25% increase), particularly in directions where the mechanical stress is absorbed by collagenous fibers (more than 90%), as supported by a histological analysis. Although compressibility of perfused tissue remained unchanged, permeability significantly reduced in 8-month-old animals. Our findings offer new insights into myocardial properties, emphasizing on local variations, which can help to get a more realistic understanding of cardiac mechanics in this common animal model. Statement of significanceIn this work, we conducted a comprehensive analysis of the passive mechanical behavior of porcine myocardial tissue through biaxial, triaxial shear, and confined compression tests. Unlike previous research, we investigated the variation in mechanical response across the left ventricular free wall, conventionally assumed homogeneous, revealing differences in terms of stiffness and compressibility. Additionally, we evaluated age-related effects on mechanical properties by comparing two age groups, observing significant variations in stiffness and permeability. To date, there has been no such in-depth exploration of myocardial elastic response and compressibility considering regional variations along the wall and may contribute to a better understanding of the cardiac tissue’s passive mechanical response.

Abstract Tu048: Viscoelastic remodeling of the left ventricular myocardium in myocardial infarction

Introduction. Myocardial infarction (MI) leads to cardiac myocyte death and the formation of a fibrotic scar in the left ventricular myocardium (LV). LV free wall (LVFW) remodeling in MI is known to significantly alter the biomechanical response of the LV and, in turn, LV function. While changes in the elastic behavior of the LVFW in MI have been reported, changes in the viscoelastic behavior of the LVFW remain understudied. Our objective in this study was to determine the changes in the stress relaxation behavior of the LVFW in MI. Methods. MI was induced in rats via the ligation of the LAD artery, and hearts were harvested for three groups: sham, 2-week (2wk), and 4wk post-MI (n=3 for each group). Prior to sacrifice, echocardiography was performed to estimate ejection fraction (EF). LVFW specimens were harvested and subjected to viscoelastic stress relaxation tests. The specimens were stretched to 15% along the circumferential and longitudinal directions and allowed to relax. The stress was normalized against the peak (initial) stress for each specimen for proper comparison across the groups. Results. The EF at 2wk and 4wk specimens was reduced compared to the sham specimens (Fig. 1A). The 4wk post-MI specimens showed slower stress relaxation compared to that in the sham and 2wk specimens in both directions (Figs. 1B, C). Considering a 2-minute stress relaxation span, the normalized stress in the 4wk specimens was significantly higher than the sham specimens in both directions (Fig. 1D). Conclusions. Our results suggest that the viscoelastic relaxation rate of the LVFW diminishes at late MI timepoints. A larger and more mature scar in the LVFW is expected to contribute to slower relaxation at late MI. Future studies can determine the effect of LVFW viscoelastic remodeling on LV diastolic dysfunction and impaired relaxation in MI.

Abstract Mo024: Integrated analysis of ex vivo biomechanical ventricular remodeling and imaging-based in vivo strain changes in a pre-clinical murine model of radiation-induced cardiotoxicity

Introduction: Thoracic radiation therapy (RT) is commonly used for the treatment of many common malignancies, such as lung and breast cancer, but carries a high risk of radiation-induced cardiotoxicity (RIC). Existing diagnosis of RIC is challenged by subclinical ventricular dysfunction, not captured by global indices of cardiac function. Understanding RIC-driven biomechanical remodeling of the myocardium will provide novel insights into developing high-fidelity imaging approaches for early detection of RIC. Methods: A pre-clinical model of RIC was developed by administering whole heart irradiation under image guidance in mice (8 Gy x 5) over five consecutive days. A longitudinal study was carried out to investigate the biomechanical response of the left ventricle (LV). Cardiac magnetic resonance imaging was performed to estimate end-systolic strains. Mechanical testing was performed on the harvested LV free wall (LVFW) specimens to measure passive stiffness, calculated as the tangent to the ensemble stress-strain curve at 30% strain. Results: A significant increase in passive LVFW stiffness was observed at 3M post-RT (Figs. 1A and B). Significant declines in both global circumferential strain (GCS) and global radial strain (GRS) at 3M post-RT, compared to respective measurements at pre-RT, were observed (Figs. 1C and D). Suppressed contractile strains suggested biomechanical remodeling of the LV, including impaired contractility and passive stiffening of the LVFW, consistent with ex-vivo measurements. Conclusion: We have established a direct correlation between ex-vivo mechanical testing (elevated stiffness) and reduced contractile strains in in-vivo analysis in a mouse model of RIC. Such integrated analysis will pave the way towards developing highly sensitive imaging approaches that non-invasively recapitulate the ventricular remodeling events associated with RIC, thereby enabling early detection of RIC in patients receiving thoracic RT.

Abstract Tu113: Metabolomic Profile of Human End-Stage Ischemic Cardiomyopathy Reveals Few Differences from Non-Ischemic Cardiomyopathy

Background: The heart is highly metabolic, relying on a range of fuels to sustain its high generation of ATP. The primary source of energy in the human heart is fatty acids, but fatty acid oxidation is reduced in failing hearts, contributing to a decrease in ATP production. Previously, we provided a comprehensive metabolic profile of human non-ischemic cardiomyopathy (NICM) hearts, including maintained ATP levels despite decreased energy charge (EC), lower acylcarnitines, acyl CoAs, and free fatty acids, suggesting a defect in fatty acid import. Research Questions: The pathogenesis of ischemic cardiomyopathy (ICM) is dramatically different from that of NICM, raising the question of whether metabolic defects differ between these two conditions. Aims: Our current study was therefore aimed at elucidating the metabolomic profile of end-stage ICM compared to that of NICM. Methods: Whole human hearts were obtained either from patients with end-stage heart failure (NICM or ICM) undergoing cardiac transplantation or from brain-dead organ donors. Hearts were arrested in situ and kept in ice-cold cardioplegia solution at all times. Transmural tissue samples were obtained from left ventricular free wall, snap frozen, and extracted metabolites were quantified by liquid chromatography coupled with mass spectrometer. Results: The comparison of metabolomics data from non-failing (NF) control heart samples and NICM samples were consistent with our previous study, with marked decrease in acylcarnitines and increase in lysophosphatidylcholine. On the other hand, the metabolomics profiles of ICM and NICM samples were remarkably similar. Phenylacetylglutamine and trimethylamine N-oxide, both related to atherosclerotic disease risk, were statistically significantly higher in ICM samples compared to NICM samples. Conclusion(s): The human cardiac metabolome of end-stage ICM is nearly identical to that of NICM, despite dramatically different pathogeneses, suggesting that end-stage heart failure constitutes a final common pathway. It would be of great interest to evaluate metabolomic profiles of the diseases differ at earlier timepoints.

Catastrophic Event Following Percutaneus Coronary Intervention Developing In-Stent Thrombosis Leading Massive Pericardial Effusion and Free Wall Rupture

BACKGROUND: One extremely unusual but serious side effect of an acute myocardial infarction is left ventricular free wall rupture. It was reported to happen either during the sub-acute phase with overt cardiac remodeling (type III, 45%) or early after the beginning of Myocardial Infarction (MI) (type I or II, about 55%). Large infarct sizes, female gender, and advanced age have all been linked to an increased risk of free wall rupture. Clinicians continue to face significant challenges in diagnosing and treating this condition because of the diverse clinical manifestations linked to elevated death rates. AIMS: This case report aims to highlight a rare occurrence of mechanical complication of acute myocardial infarction CASE: A 69-year-old male patient was referred because of chest pain and dyspneu. He had a primary Percutaneous Coronary Intervention (PCI) and was diagnosed with posterior ST-Evelation Myocardial Infarction (STEMI). The patient had a stent inserted into his ostial-distal Left Circumflex (LCx) artery. Three weeks later, a reangiography revealed a left ventricle (LV) aneurysm and stent thrombosis. Massive pericardial effusion with free wall rupture was seen on the echo. He was breathing heavily while in our emergency room. His blood pressure was 125/74 (94) heart rate was 94 bpm respiratory rate 24 times/minute, SpO2 was 98%, there were no rales, and his ankles had pitting edema. By the bedside, Echo revealed an LV aneurysm, a large, localized pericardial effusion without tamponade, and a possible free wall rupture. Later, he was taken to the intensive care unit and had heart surgery DISCUSSION: Complications from an acute myocardial infarction may be ischemic, mechanical, arrhythmic, embolic, or inflammatory. Significant short-term clinical improvement and long-term survival are linked to the emergence of mechanical problems following acute myocardial infarction. CONCLUSION: the fact that primary Percutaneous Coronary Intervention (PCI) has significantly reduced the prevalence of this deadly event. Our results indicate that one of the key predictors and primary causes of this problem is a longer symptom of angiography time.

The 3-year follow-up of a fully biodegradable implantable device closure for perimembranous ventricular septal defects in children using echocardiography.

The aim of this study was to investigate the morphologic changes of a novel fully biodegradable implantable device after closing a perimembranous ventricular septal defect (Pm-VSD) and to evaluate the effect of the occluder on the myocardial function in patients during a 3-year follow-up period. One-year, 2-year, and 3-year follow-ups were carried out after implantation with a total of 30 Pm-VSD patients who had successful closure by the fully biodegradable occluder. In total, 30 healthy children were enrolled as controls. At discharge and at every follow-up visit, the lengths of the left and right discs of the novel device were measured in the apical three- and four-chamber as well as short-axis views. At the end of the follow-up, using three-dimensional speckle-tracking conditions, the values of myocardial deformation, including global longitudinal strain, global circumferential strain, and global area strain, were acquired. The fully bioabsorbable double-disc occluder gradually decreased over time and was eventually invisible under echocardiographic scanning during the follow-up (p < 0.05). At the end of the third year, there were no significant differences in the myocardial deformation parameters between the cases implanted with the novel devices and the controls; no significant differences were found between the basal segments of the ventricle septa and that of the left ventricle (LV) free wall among the patients who completed the Pm-VSD closure using the fully biodegradable occluder (p > 0.05). The novel fully biodegradable occluder is a safe, effective, and perfect alternative for the treatment of VSD. Echocardiography plays a crucial role in the follow-up of this new type of occluder implantation.