Myocardial Wall Research Articles

The capabilities of cardiac MRI in the differential diagnosis of AL- and ATTR-amyloid cardiomyopathy.

BACKGROUND. Cardiac amyloidosis is a serious progressive disease with a high mortality rate. Differentiation between AL and ATTR types of amyloidosis is critically important for choosing the optimal treatment. AIM. This study aims to evaluate the capabilities of cardiac MRI in the differential diagnosis of AL and ATTR amyloidosis. METHODS. A retrospective analysis of medical data from 25 patients with confirmed cardiac amyloidosis (12 with AL and 13 with ATTR) was conducted. These patients underwent contrast-enhanced cardiac MRI, and their structural parameters (particularly wall thickness and myocardial mass), ventricular function, and late gadolinium enhancement (LGE) patterns were assessed. Standard statistical methods were used, with p-values 0.05 considered significant. RESULTS. Patients with ATTR amyloidosis exhibited more pronounced myocardial wall thickening (LV septal wall 17.8±2.3 mm vs 13.8±2.4 mm, p0.01; LV posterior wall 14.2±2.4 mm vs 10.8±2.0 mm, p0.01) and greater LV myocardial mass (110±30 vs 83±17 g/m², p0.01) compared to those with AL amyloidosis. In ATTR amyloidosis, transmural LGE was more frequently observed in the basal and mid inferior-lateral segments of the left ventricle, while subendocardial LGE was more common in the mid anterior and inferior-lateral segments (p0.05). A distinguishing feature of ATTR was the simultaneous contrast uptake in subendocardial layers of both the LV and RV in the area of the interventricular septum (100% vs 50%, p0.01). RV LGE was more common in ATTR (100% vs 58%, p0.05), particularly in the interventricular septum and the inferior wall of the RV (p0.05). Quantitative assessment of LGE using the QALE scale showed more extensive enhancement in ATTR (13 [12;14] vs 10.5 [1.75;12], p0.01). A score of more than 13 allowed differentiation between the types of amyloidosis with a sensitivity of 69% and specificity of 83%. CONCLUSION. Cardiac MRI can identify characteristic differences between AL and ATTR amyloidosis, which may assist in their differential diagnosis. Further research is needed to confirm the diagnostic accuracy of the identified MRI features.

Peak systolic velocity of right ventricular free wall myocardium by tissue Doppler imaging does not help to identify patients with acute pulmonary embolism and stratify 30-day mortality risk in all-comers with acute pulmonary embolism

Peak systolic velocity of right ventricular free wall myocardium by tissue Doppler imaging does not help to identify patients with acute pulmonary embolism and stratify 30-day mortality risk in all-comers with acute pulmonary embolism

Influence of peak exercise-induced blood pressure on basal to apical myocardial wall thickness in elite athletes: a sex-specific CMR study

Abstract Background Understanding the sex-specific physiological remodelling response of the myocardial walls to peak exercise-induced blood pressure (SBPpeak) is essential for distinguishing healthy adaptation from pathological remodelling in athletes. Purpose We investigated how SBPpeak relates to myocardial wall thickness measured using cardiac magnetic resonance imaging (CMR) in elite athletes. Methods Cross-sectional analysis of healthy elite athletes included in the ELITE study who underwent both cardiopulmonary exercise testing (CPET) and CMR. Imaging software’s built-in AI option determined average end-diastolic wall thicknesses of all sixteen AHA-defined segments on short-axis cine images with four-chamber long-axis reference. Our primary metrics of interest were Spearman's correlations between SBPpeak and left ventricular mass indexed to body surface area (LVM/BSA), as well as average wall thickness across the sixteen myocardial segments, stratified by sex and endurance/non-endurance sports status. Secondary analyses involved regression models to evaluate the influence of SBPpeak on myocardial wall thickness, adjusting for sex, body size, CPET variables and sport type. Results In 75 athletes (median age: 24; 71% female; 61% engaged in endurance sports), CPET and CMR were performed within a median interval of 5 months [interquartile range: 1-13 months]. SBPpeak was similar in female and male athletes (170 [160-180] vs. 174 [169-184] mmHg, p=0.121, respectively) and in endurance and non-endurance athletes (both 170 [160-180] mmHg, p=0.625). Female elite athletes showed weak to moderate positive correlations between SBPpeak and the majority of basal and mid-ventricular AHA segments (rho = 0.27 – 0.48, Figure). This was most pronounced in the mid-ventricular anterolateral segment (AHA06: rho = 0.48, p<0.001). LVM/BSA in females was positively correlated with SBPpeak (rho = 0.31, p=0.025). Male elite athletes demonstrated greater absolute wall thickness across all AHA segments compared to females, however, there was a moderate correlation with SBPpeak exclusive to the basal anterior segment (AHA01: rho = 0.48, p=0.028). Backward stepwise multivariate regression analyses (Table) revealed SBPpeak as an independent predictor of the thickness of all basal AHA segments except for the basal inferoseptal segment (AHA03), and the mid-anterior and anterolateral segments. Associationswere maintained after adjustment for maximum wattage, body surface area, and sex, with type of sports consistently excluded from the models. Conclusion In the extreme phenotypes of elite athletes, SBPpeak correlates especially with basal myocardial thickness, independent of sex, BSA and maximum work rate influences. We found stronger associations between SBPpeak and myocardial adaptation in female athletes. These findings suggest a paramount role of exercise-induced blood pressure on basal myocardial remodelling surpassing the effect of sports type.Figure:segmental polar plot (heat map)Table:GAM regression models

Association between impaired left ventricular global longitudinal strain and B-type natriuretic peptide in obstructive hypertrophic cardiomyopathy

Abstract Background Left ventricular global longitudinal strain (LV-GLS) is considered valuable in explaining impaired left ventricular contractility in hypertrophic cardiomyopathy (HCM) with preserved ejection fraction and is associated with worse outcome. Elevated B-type natriuretic peptide (BNP) is a biomarker of increased LV wall stretch and a risk factor of heart failure, mortality, and other adverse cardiovascular events. However, relationship between GLS and BNP has not received sufficient attention in the obstructive variant of HCM. Purpose This study aimed to determine the association between echocardiographic LV-GLS and plasma BNP in patients with hypertrophic obstructive cardiomyopathy (HOCM). Methods A total of 145 consecutive patients (32% females) with symptomatic HOCM were enrolled in the retrospective study. HOCM was defined with a maximum end-diastolic wall thickness ≥15mm without other etiologies for LV hypertrophy, and peak LV outflow tract (LVOT) gradient ≥30mmHg. The echocardiographic parameters regarding LV geometry, loading conditions, and GLS were evaluated according to guidelines. Patients were divided into two groups according to absolute GLS values (greater or lower than median LV-GLS). Patient baseline clinical data, echocardiographic parameters, and BNP were compared. Univariate and multivariable regression analysis were applied to identify the independent determinator of LV-GLS. Results The median value of LV-GLS of this study cohort was -13.4%. Eighty-one patients (47.6±13.4 years-old) had a |GLS|≥13.4% and 64 individuals (48.7±12.6 years-old) had a |GLS|<13.4%. No differences were found in age, gender, physical examinations, LVEF, cardiovascular comorbidities, or active medications between the two groups, except for body mass index (BMI). Patients with |GLS|≥13.4% had statistically lower BMI (24.58±2.42 vs. 26.00±3.12kg/m², p=0.030). BNP was found significantly elevated in patients with |GLS|<13.4% when compared with individuals with |GLS|≥13.4% {median (IQR); 550.05 (214.50, 899.35) vs. 182.40 (78.90, 479.90)pg/mL, p=0.004}. In univariate regression analysis, decreased |GLS| was associated with male gender, maximum and mean LV wall thickness, peak LVOT gradient, reduced mitral annular e’ velocity, elevated BNP and cardiac troponin I. In multivariable regression analysis, GLS was found independently associated with mean LV wall thickness and BNP. Conclusions In patients with symptomatic HOCM with preserved ejection fraction, impaired LV-GLS was found to be associated with plasma BNP and mean LV wall thickness, independent of gender, age, loading conditions, LVEF, or LVOT gradient. Reduced GLS may be a more sensitive surrogate in assessing increased myocardial wall tension or stretch, rather than LV contractility in these patients. Therefore, the interpretation of GLS in HOCM should shift away from systolic interest toward emphasizing its potential value in risk stratification of diastolic heart failure with preserved LVEF.Figure 1

Clustering analysis based on clinically available data for improving risk stratification and outcome prediction of hypertension

Abstract Background Hypertension (HTN) is a heterogeneous condition with several factors contributing to adverse outcomes. Machine learning can harness complex data to unveil outcome predictors and guide prevention. Purpose To use clustering analysis on clinical data to identify HTN risk profiles and their associations with cardiovascular abnormalities and clinical outcomes. Methods A cohort of 14,840 UK Biobank hypertensive participants without pre-existing heart failure (HF) who underwent cardiovascular magnetic resonance (CMR) assessment was examined using K-means clustering on 79 clinical attributes. The clusters’ association with incident HF, mortality, atrial fibrillation (AF), and major adverse cardiovascular events (MACE) were evaluated, alongside imaging characteristics, with mediation analysis probing the role of imaging in risk differentiation. All post-hoc analyses were adjusted for vascular risk factors (VRFs), including diabetes, hypercholesterolaemia, previous myocardial infarction. Results Three distinct clusters differing considerably in lifestyle habits, cardiovascular risk factors, electrocardiographic parameters, and cardiometabolic profiles were identified. Cluster 1 (lowest risk), predominantly females, exhibited the most favourable metabolic profile and outcomes. Cluster 2 (highest risk), predominantly males, had the most adverse metabolic and cardiovascular profiles, and the highest risk of all adverse outcomes, especially AF and HF (hazard ratio (HR) 1.80 [1.45–2.25] and 1.85 [1.39–2.46]; p <0.005). This group was associated with more eccentric LV hypertrophy (LVH), overall poorer left atrial emptying function (LAEF), bi-ventricular systolic function and LV mechanics, and higher systemic vascular resistance (Figure 1). Cluster 3 (intermediate risk) was a more heterogeneous group with the highest burden of diabetes and adiposity and a moderate rise in AF and MACE risk (HR 1.61 [1.12-2.32] and 1.30 [1.07-1.58]; p <0.05). This cluster was associated with concentric LV remodelling and better indices of cardiac mechanics, but greater impairment in LA booster pump function (active LAEF) than Cluster 2 (Figure 1). Cluster 2's effect on MACE was mostly mediated through LV mass increase (proportion mediated, 67%), followed by changes (reducing) in LV global longitudinal strain (33%), and ejection fraction (25.4%). The indirect effect of CMR changes in the association between cluster 3 and MACE was much smaller with the highest proportion of the effects mediated through increased myocardial wall thickness (26%) but not LV mass, and changes in all the components of LA function. Conclusions Clinical data clustering provides insight into distinct HTN risk profiles, each with specific imaging characteristics and clinical trajectories, hinting at different pathophysiological mechanisms. Enhanced phenotyping can facilitate tailored interventions based on the disease subtype and improve clinical outcomes.Figure 1.

Strain rate during isovolumic relaxation as a prognostic biomarker for long-term cardiovascular morbidity and mortality: an exploratory study on a general population.

Left ventricular (LV) strain rate (SR) during early relaxation correlates with LV filling pressures and has been assessed as a prognostic biomarker in several cardiac diseases. Conversely, even though LV SR during isovolumic relaxation (SRIVR)is more strongly related to invasive measurements of LV diastolic function, to date, studies on the role of SRIVR in the long-term prognosis assessment are lacking. Thus, the goal of this study was to assess the potential additive prognostic value of SRIVR on top of conventional cardiovascular risk factors in a general population. 657 subjects (mean age 51.6y; 47.6% males) were included in this study and, besides clinical and standard echocardiographic assessment, tissue Doppler imaging (TDI)-based SR was measured during IVR (SRIVR), early diastole (SRe), and atrial contraction (SRa) in the mid-segment of the inferior, inferolateral, lateral, and septal wall of the LV. During the follow-up period (median 12.1years), the total number of major adverse cardiac events was 85 (13.4%). Overall, after adjustment for known cardiovascular risk factors and important echocardiographic indices in a multivariable-adjusted Cox regression model, SRIVR of the inferolateral wall (SRIVRinflat) remained an independent predictor of fatal and nonfatal cardiac events (HR: 1.49, p = 0.016), along with GLS (HR: 1.35, p = 0.027), age (HR: 1.09, p < 0.001), and male sex (HR: 2.06, p = 0.037). None of SRIVR measured in the other myocardial walls were associated with cardiac outcome. SRIVRinflat predicted adverse outcome in the general population, on top of conventional cardiovascular factors. However, its incremental value as a prognosticator remained limited.

In vitro characterization of radiofrequency ablation lesions in equine and swine myocardial tissue

Radiofrequency ablation is a promising technique for arrhythmia treatment in horses. Due to the thicker myocardial wall and higher blood flow in horses, it is unknown if conventional radiofrequency settings used in human medicine can be extrapolated to horses. The study aim is to describe the effect of ablation settings on lesion dimensions in equine myocardium. To study species dependent effects, results were compared to swine myocardium. Right ventricular and right and left atrial equine myocardium and right ventricular swine myocardium were suspended in a bath with circulating isotonic saline at 37 °C. The ablation catheter delivered radiofrequency energy at different-power-duration combinations with a contact force of 20 g. Lesion depth and width were measured and lesion volume was calculated. Higher power or longer duration of radiofrequency energy delivery increased lesion size significantly in the equine atrial myocardium and in equine and swine ventricular myocardium (P < 0.001). Mean lesion depth in equine atrial myocardium ranged from 2.9 to 5.5 mm with a diameter ranging from 6.9 to 10.1 mm. Lesion diameter was significantly larger in equine tissue compared to swine tissue (P = 0.020). Obtained data in combination with estimated wall thickness can improve lesion transmurality which might reduce arrhythmia recurrence. Optimal ablation settings may differ between species.

Feasibility and safety assessment of RF double applications in very high power and short duration ablation

BackgroundThe QDOT-MICRO catheter enables very high power and short duration (vHPSD) ablation. However, low first-pass isolation rates have been reported, possibly because of shallow lesion formation, necessitating deeper lesions to improve treatment outcomes. ObjectiveThis study aimed to confirm the safety and efficacy of double radiofrequency applications of vHPSD ablation in an in vivo beating swine heart model. MethodsEighteen swine were anesthetized and underwent vHPSD ablation using the QDOT-MICRO catheter at 90 W for 4 seconds, targeting a contact force of 10 g. Radiofrequency applications were performed as single application (SA) and double applications (DAs) with 4- to 8-second rest intervals. Lesion surface area and volume were measured postablation. ResultsA total of 337 atrial lesions and 74 ventricular lesions were created. Both 4- to 6-second DA and 7- to 8-second DA produced significantly larger and deeper lesions than did SA, with atrial surface lengths averaging 9.0 mm for 4- to 6-second DA, 9.2 mm for 7- to 8-second DA, and 8.0 mm for SA. Transmurality was observed at 100% for 4- to 6-second and 7- to 8-second DAs, while it was 94% for SA (P = .002). Ventricular lesion metrics followed similar trends. Except for 1 event of tiny char formation during 4-second DA in the ventricle, neither steam pops nor char formation was observed in either the atrium or the ventricle. ConclusionIn an in vivo swine heart model, DA with 4- to 6-second and 7- to 8-second intervals create deeper and wider lesions than does SA, suggesting its potential for clinical application in areas with thicker myocardial walls. However, DA with very short intervals may still pose a risk of excessive tissue heating.

Evaluation of Left Ventricular Remodeling and Prognosis after PCI in Acute Myocardial Infarction Using Real-Time, Three-Dimensional Echocardiography Combined with Layer-Specific Strain Imaging

Aim: This study aimed to evaluate left atrial and left ventricular volumes, strains, and strain rates in patients with acute ST-segment elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention (PCI) using real-time three-dimensional echocardiography and layer-specific strain techniques. The relationships between these parameters and left ventricular remodeling (LVR) and prognosis were also explored. Methods: The study included 217 patients with first-episode STEMI who underwent emergency PCI. Echocardiography and myocardial strain analyses were performed within 24 h post-PCI. Patients were categorized into early and non-early LVR groups based on the increase in left ventricular end-diastolic volume (LVEDV). The occurrence of major cardiovascular adverse events (MACE) was followed up for one-year post-PCI. Differences in clinical data and ultrasound parameters between the groups were compared, and the predictive value of myocardial strain indicators for late LVR was analyzed using a multivariate logistic regression model and receiver operating characteristic (ROC) curves. Results: Early LVR occurred in 54.8% of patients and was characterized by decreased left ventricular systolic function, more segments with abnormal movement, and reduced absolute strain values in the three layers of the left ventricular wall myocardium, with a compensatory increase in left atrial strain rate during the contraction phase. The early LVR group showed a higher incidence of MACE at the one-year follow-up. At 6 months post-PCI, 29.9% of patients developed late LVR, which was not completely related to early LVR. Late LVR was associated with a higher incidence of MACE. The longitudinal strain value of each layer of left ventricular myocardium obtained from layer-specific strain imaging showed predictive value for advanced LVR. Conclusions: More than half of patients with STEMI develop early LVR post-PCI, with a higher incidence of MACE during one-year of follow-up, necessitating attention to early LVR in clinical practice. Late LVR, which develops in some patients after 6 months, is also linked to a higher incidence of MACE. Accurate monitoring of the myocardial deformation function using layer-specific strain imaging is expected to become a reference indicator for clinical diagnosis and treatment. Monitoring the structure and function of the left atrium and mitral valve alongside the LVR is important for prognostic assessment and for formulating diagnostic and treatment plans.

Regional impairment of left ventricular longitudinal strain in aortic regurgitation

BackgroundAortic regurgitation (AR) has an important impact on myocardial mechanics and recent studies have proved the value of global longitudinal strain (GLS) in the assessment of its severity and prognosis. Our purpose was to assess if the direct impact of the regurgitant jet on the myocardial wall could affect regional longitudinal strain.MethodsEighty patients with chronic moderate/severe AR were retrospectively studied. Patients were considered to have a jet-related longitudinal strain reduction when the myocardial segments directly impacted by the jet had their longitudinal strain reduced by at least 30% compared to nonaffected segments. AR severity, left ventricular (LV) size and function were compared according to the presence/absence of this regional pattern. For those who underwent surgery, postoperative regional and global LV function was also analyzed.ResultsA pattern of regional longitudinal strain impairment was identified in 43% of patients, with a regional reduction (in median) of 10 percentage points in absolute strain values in the segments impacted by the jet, compared to nonaffected segments. In the subgroup who underwent surgery, this pattern became attenuated after surgery. Patients with regional longitudinal strain impairment were less likely to improve GLS after surgery (10% vs. 38% improved GLS by at least 2.5%, P = 0.049).ConclusionsTo our knowledge, this study identifies for the first time, a link between the location of the impact of the regurgitant jet in AR and regional longitudinal strain impairment. The presence of this regional pattern might be associated with worse postoperative LV recovery.

Computational modeling of left ventricular flow using PC-CMR-derived four-dimensional wall motion.

Intracardiac hemodynamics plays a crucial role in the onset and development of cardiac and valvular diseases. Simulations of blood flow in the left ventricle (LV) have provided valuable insight into assessing LV hemodynamics. While fully coupled fluid-solid modelings of the LV remain challenging due to the complex passive-active behavior of the LV wall myocardium, the integration of imaging-driven quantification of structural motion with computational fluid dynamics (CFD) modeling in the LV holds the promise of feasible and clinically translatable characterization of patient-specific LV hemodynamics. In this study, we propose to integrate two magnetic resonance imaging (MRI) modalities with the moving-boundary CFD method to characterize intracardiac LV hemodynamics. Our method uses the standard cine cardiac magnetic resonance (CMR) images to estimate four-dimensional myocardial motion, eliminating the need for involved myocardial material modeling to capture LV wall behavior. In conjunction with CMR, phase contrast-MRI (PC-MRI) was used to measure temporal blood inflow rates at the mitral orifice, serving as an additional boundary condition. Flow patterns, including velocity streamlines, vortex rings, and kinetic energy, were characterized and compared to the available data. Moreover, relationships between LV wall kinematic markers and flow characteristics were determined without myocardial material modeling and using a non-rigid image registration (NRIR) method. The fidelity of the simulation was quantitatively evaluated by validating the flow rate at the aortic outflow tract against respective PC-MRI measures. The proposed methodology offers a novel and feasible toolset that works with standard PC-CMR protocols to improve the clinical assessment of LV characteristics in prognostic studies and surgical planning.

Evaluation of Right Ventricular Myocardial Properties Using Systolic Myocardial T1 Mapping.

Introduction Myocardial properties can be quantitatively evaluated using myocardial native T1 values (nT1) obtained using cardiac magnetic resonance imaging (CMR). In terms of myocardial wall thickness, the left ventricular nT1 is easy to measure, but the right ventricular nT1 is difficult. Patients with congenital heart disease often develop right ventricular overload. If right ventricular nT1 can be measured consistently, inflammation and fibrosis of the right ventricular myocardium can be quantitatively evaluated. We aimed to determine whether T1 mapping during systole can be used to evaluate right ventricular myocardial properties. Methods T1 mapping was performed at diastole and systole. Systolic T1 mapping was calculated from diastolic T1 mapping and cine images. The myocardial properties of both ventricles were evaluated in 13 healthy volunteers (21-26 years old) and 12 patients with right ventricular overload (12-41 years old) who underwent CMR examination at our hospital. Results From the analysis of left ventricular nT1, we found that nT1 did not change significantly during the cardiac cycle. However, right ventricular nT1 changed between diastole and systole because the right ventricle is affected by blood. Although there was no difference in right ventricular diastolic nT1 between the patients and volunteers (1,346.8 vs. 1,347.6 ms, p = 0.852), the right ventricular systolic nT1 was significantly higher in patients than in volunteers (1,312.7 vs. 1,233.8 ms, p = 0.002). This indicates that right ventricular myocardial damage occurs in patients with right ventricular overload. Conclusion Systolic right ventricular myocardial T1 mapping allows assessment of right ventricular myocardial properties. The right ventricular myocardial systolic nT1 is useful for evaluating myocardial damage due to right ventricular stress and myocardial injury. Measuring right ventricular nT1 may allow consideration of early therapeutic intervention.

Abstract We090: Antagonistic and Cooperative Dynamics of Irx3 and Irx4 in Ventricular Compaction

Left ventricular non-compaction cardiomyopathy (LVNC) is a rare heart condition characterized by excessive trabeculae and intertrabecular recesses in the left ventricle of the heart. It is believed to be caused by abnormal trabecular compaction process, which involves trabecular remodelling to form a thick myocardial wall. Embryonic trabeculae consist of bipotent progenitors that differentiate into the ventricular conduction system (VCS) and contractile cardiomyocytes, yet it remains to be further understood how the pathways involved in trabecular cell specifications play a role in the compaction process. Here we present two transcription factors, Iroquois homeobox 3 ( Irx3 ) and Irx4 , playing antagonistic and cooperative roles during trabecular specification and maturation, thereby facilitating proper ventricular compaction. Our single-cell RNA sequencing analysis revealed that the differentiation of trabecular cells into VCS cells was accompanied by increased Irx3 but decreased Irx4 expression. In addition, we found that the loss of Irx4 led to both an increased expression level of Irx3 and an expansion in the number of Irx3 -expressing cells. Conversely, the loss of Irx3 resulted in an upregulation of Irx4 expression within VCS cells. Next, to investigate the functional importance of the antagonistic relationship between Irx3 and Irx4 in trabecular differentiation, we generated Irx3 and Irx4 compound knockout (KO) mice and examined the structure and function of their hearts. Notably, unlike Irx3 KO hearts showing normal ventricular myocardium, Irx4 KO hearts exhibited mild LVNC, and Irx3 and Irx4 double knockouts ( Irx3 /4dKO) hearts displayed severe LVNC. Multiome sequencing of E14.5 ventricles revealed that Irx3 /4dKO ventricles contained an increased number of trabecular cells, expressing higher levels of cell proliferation markers and altered trabecular identity genes, compared to littermate controls. Collectively, our results demonstrate that balanced antagonism between Irx3 and Irx4 is crucial for establishing trabecular identity. This highlights the importance of proper differentiation of trabeculae into the VCS and non-VCS contractile cells during ventricular compaction, thereby preventing noncompaction cardiomyopathy.

Advances in Surgical Treatments of Left Ventricular Aneurysms.

Despite improvements in the early intervention of myocardial infarction (MI) in recent decades, left ventricular aneurysms (LVA) remain a major health concern, particularly in developing nations. The progression of MI can lead to the thinning of the myocardial wall and the formation of a ventricular wall bulge, characteristic of an LVA. Furthermore, cardiac magnetic resonance (CMR) has emerged as the gold standard for LVA diagnosis due to its superior imaging capabilities. Notably, surgical ventricular reconstruction (SVR) is an effective treatment for LVA, aiming to restore the normal volume and structure of the left ventricle, thereby improving cardiac function. However, the criteria for selecting patients for SVR treatment remains a subject of debate. This review focuses on the current understanding of surgical indications, procedures, and prognostic risk factors that influence outcomes in left ventricular reconstruction, highlighting the need for precise patient selection to optimize surgical benefits.

Early left atrial reverse remodelling in patients with hypertrophic obstructive cardiomyopathy receiving transapical beating-heart septal myectomy.

This study aims to investigate the short-term effects of transapical beating-heart septal myectomy (TA-BSM) on left atrial (LA) anatomy and function and its association with clinical indicators in patients with hypertrophic obstructive cardiomyopathy (HOCM). A total of 105 HOCM patients who received TA-BSM were included. Clinical and comprehensive echocardiographic data were obtained before surgery, at discharge, and 3 months after myectomy. LA reverse remodelling was defined as LA maximum volume index (LAVI) ≤34 ml/m2 and a change of ≥10%. At 3 months after TA-BSM, New York Heart Association (NYHA) functional class and 6-min walking test were significantly improved, N-terminal pro-B-type natriuretic peptide (NT-proBNP) decreased, left ventricular outflow tract (LVOT) peak gradient and mitral regurgitation were significantly reduced. LAVI decreased in 76%, with a median change of 20%, and the criteria for LA reverse remodelling were met in 48%. LA strain parameters were improved at 3 months after TA-BSM. Moreover, left ventricular (LV) diastolic function was significantly improved, but LV global longitudinal strain was not significantly changed at 3 months after operation. Improvement in LVOT peak gradient, LAVI, LA reservoir strain (LASr) and conduit strain (LAScd) were associated with reduction in NT-proBNP. Along with effectively relieving the obstruction of the LVOT and mitral regurgitation, TA-BSM could significantly improve LA size and function during the short-term follow-up for HOCM patients. The indicators of LA reverse remodelling were associated with reduction in a biomarker of myocardial wall stress, indicating the early recovery of LV relaxation and clinical status for patients.

Self-supervised learning for improved calibrationless radial MRI with NLINV-Net.

To develop a neural network architecture for improved calibrationless reconstruction of radial data when no ground truth is available for training. NLINV-Net is a model-based neural network architecture that directly estimates images and coil sensitivities from (radial) k-space data via nonlinear inversion (NLINV). Combined with a training strategy using self-supervision via data undersampling (SSDU), it can be used for imaging problems where no ground truth reconstructions are available. We validated the method for (1) real-time cardiac imaging and (2) single-shot subspace-based quantitative T1 mapping. Furthermore, region-optimized virtual (ROVir) coils were used to suppress artifacts stemming from outside the field of view and to focus the k-space-based SSDU loss on the region of interest. NLINV-Net-based reconstructions were compared with conventional NLINV and PI-CS (parallel imaging + compressed sensing) reconstruction and the effect of the region-optimized virtual coils and the type of training loss was evaluated qualitatively. NLINV-Net-based reconstructions contain significantly less noise than the NLINV-based counterpart. ROVir coils effectively suppress streakings which are not suppressed by the neural networks while the ROVir-based focused loss leads to visually sharper time series for the movement of the myocardial wall in cardiac real-time imaging. For quantitative imaging, T1-maps reconstructed using NLINV-Net show similar quality as PI-CS reconstructions, but NLINV-Net does not require slice-specific tuning of the regularization parameter. NLINV-Net is a versatile tool for calibrationless imaging which can be used in challenging imaging scenarios where a ground truth is not available.

F-18 FDG PET/CT scan in recurrent prosthetic valve endocarditis without detectable abnormality on echo: a case report

BackgroundInfective endocarditis poses many clinical and diagnostic challenge. The diagnosis of infective endocarditis is made by high index of clinical suspicion based on the American Heart Association modified Duke’s criteria, and the main imaging modality of choice is echocardiography.Case presentationHere, we reported a case of recurrent infective endocarditis revealed by FDG PET/CT study despite completion of antibiotics and negative on echocardiography. A 38-year-old female with history of double-valve replacement for aortic stenosis presented with 1-week history of chest pain, dyspnea and intermittent fever. She was treated with 5 weeks of antibiotic with IV Cephalexin for prosthetic valve endocarditis. The repeated blood culture after IV antibiotic was negative for infection. She represented again with episodes of palpitation. Post-treatment blood investigation showed normal leukocyte level with increasing CRP and Troponin T level. The repeated blood culture and transesophageal echo was negative. The F-18 FDG PET/CT showed a mild hypermetabolic focus at the inferior basal myocardial wall adjacent to the prosthetic valve, however not involving the paraaortic region which is likely secondary to ongoing inflamed myocardium. As the fear of another relapse of endocarditis, oral suppression antibiotic therapy was continued for another 6 months.ConclusionsThis case report illustrates a patient with a prosthetic valve replacement detected by F-18 FDG PET/CT, which one could have overlooked an endocarditis if one had relied on transesophageal echo (TEE) alone. F-18 FDG PET/CT is a promising adjunctive tool in the diagnostic workup of patients with suspected IE, particularly prosthetic device endocarditis where the TEE sensitivity is lower. In our patient, the positive F-18 FDG PET/CT governs the subsequent therapeutic consequences which include adjustment of antibiotic and length of treatment, and it prevents unnecessary intervention.

Investigating the Link Between Left Ventricular Hypertrophy and Anemia in End-Stage Renal Disease

Background:ESRD significantly burdens healthcare systems worldwide. Its related complications, such as LVH and anemia, lead to increased morbidity and mortality. Left Ventricular Hypertrophy (LVH), which mirrors an increase in myocardial mass and wall thickness, is easily identified in patients with ESRD. Anemia, a state of low hemoglobin, increases cardiac work Aims and Objective: To explore anemia and its association with LVH in ESRD patients on maintenance hemodialysis by detailed echocardiographic assessment and comprehensive blood analysis. Methodology: This comparative study was carried out at a teaching hospital, namely Ghurki Teaching Hospital and a tertiary care hospital, Mayo Hospital, Lahore, Pakistan from March 2023 to April 2024. A purposive sample of 200 adults on maintenance hemodialysis with ESRD was obtained through stratified random sampling techniques and the participants were grouped based on anemia status: anemic; (hemoglobin &lt;13g/dL in males, &lt;12g/dL in females) or non-anemic. The data were analyzed using SPSS software (Version 26) by employing independent t-test to compare the means, chi-squared test for categorical variables, A p-value &lt; 0. 05 was considered significant. Results:In patients with anemia, the LVMI was significantly (P≤0.05) higher than in patients without anemia. Anemia was found to be a significant (P≤0.05) predictor of an increase in LVMI over time, indicating its role in the development of LVH. Conclusion:The findings of present research indicated that, as shown by echocardiography, there is a substantial correlation between LVH and anemia in patients on maintenance of hemodialysis.

Injectable Hydrogels in Cardiovascular Tissue Engineering.

Heart problems are quite prevalent worldwide. Cardiomyocytes and stem cells are two examples of the cells and supporting matrix that are used in the integrated process of cardiac tissue regeneration. The objective is to create innovative materials that can effectively replace or repair damaged cardiac muscle. One of the most effective and appealing 3D/4D scaffolds for creating an appropriate milieu for damaged tissue growth and healing is hydrogel. In order to successfully regenerate heart tissue, bioactive and biocompatible hydrogels are required to preserve cells in the infarcted region and to bid support for the restoration of myocardial wall stress, cell survival and function. Heart tissue engineering uses a variety of hydrogels, such as natural or synthetic polymeric hydrogels. This article provides a quick overview of the various hydrogel types employed in cardiac tissue engineering. Their benefits and drawbacks are discussed. Hydrogel-based techniques for heart regeneration are also addressed, along with their clinical application and future in cardiac tissue engineering.

Llgl1 mediates timely epicardial emergence and establishment of an apical laminin sheath around the trabeculating cardiac ventricle.

During heart development, the embryonic ventricle becomes enveloped by the epicardium, which adheres to the outer apical surface of the heart. This is concomitant with onset of ventricular trabeculation, where a subset of cardiomyocytes lose apicobasal polarity and delaminate basally from the ventricular wall. Llgl1 regulates the formation of apical cell junctions and apicobasal polarity, and we investigated its role in ventricular wall maturation. We found that llgl1 mutant zebrafish embryos exhibit aberrant apical extrusion of ventricular cardiomyocytes. While investigating apical cardiomyocyte extrusion, we identified a basal-to-apical shift in laminin deposition from the internal to the external ventricular wall. We find that epicardial cells express several laminin subunits as they adhere to the ventricle, and that the epicardium is required for laminin deposition on the ventricular surface. In llgl1 mutants, timely establishment of the epicardial layer is disrupted due to delayed emergence of epicardial cells, resulting in delayed apical deposition of laminin on the ventricular surface. Together, our analyses reveal an unexpected role for Llgl1 in correct timing of epicardial development, supporting integrity of the ventricular myocardial wall.