Bioenergetics Consequences of Mitochondrial Transplantation in Cardiomyocytes.

Background Mitochondrial transplantation has been recently explored for treatment of very ill cardiac patients. However, little is known about the intracellular consequences of mitochondrial transplantation. This study aims to assess the bioenergetics consequences of mitochondrial transplantation into normal cardiomyocytes in the short and long term. Methods and Results We first established the feasibility of autologous, non-autologous, and interspecies mitochondrial transplantation. Then we quantitated the bioenergetics consequences of non-autologous mitochondrial transplantation into cardiomyocytes up to 28 days using a Seahorse Extracellular Flux Analyzer. Compared with the control, we observed a statistically significant improvement in basal respiration and ATP production 2-day post-transplantation, accompanied by an increase in maximal respiration and spare respiratory capacity, although not statistically significantly. However, these initial improvements were short-lived and the bioenergetics advantages return to the baseline level in subsequent time points. Conclusions This study, for the first time, shows that transplantation of non-autologous mitochondria from healthy skeletal muscle cells into normal cardiomyocytes leads to short-term improvement of bioenergetics indicating "supercharged" state. However, over time these improved effects disappear, which suggests transplantation of mitochondria may have a potential application in settings where there is an acute stress

Estimation of elastic and viscous properties of the left ventricle based on annulus plane harmonic behavior

Assessment of left ventricular (LV) function with an emphasis on contractility has been a challenge in cardiac mechanics during the recent decades. The LV function is usually described by the LV pressurevolume (P-V) diagram. The standard P-V diagrams are easy to interpret but difficult to obtain and require invasive instrumentation for measuring the corresponding volume and pressure data. In the present study, we introduce a technique that can estimate the viscoelastic properties of the LV based on harmonic behavior of the ventricular chamber and it can be applied non-invasively as well. The estimation technique is based on modeling the actual long axis displacement of the mitral annulus plane toward the cardiac base as a linear damped oscillator with time-varying coefficients. The time-varying parameters of the model were estimated by a standard Recursive Linear Least Squares (RLLS) technique. LV stiffness at end-systole and end diastole was in the range of 61.86-136.00 dyne/g.cm and 1.25-21.02 dyne/g.cm, respectively. The only input used in this model was the long axis displacement of the annulus plane, which can also be obtained non-invasively using tissue Doppler or MR imaging

The Current Landscape of Artificial Intelligence in Imaging for Transcatheter Aortic Valve Replacement

Purpose: This review explores the current landscape of AI applications in imaging for TAVR, emphasizing the potential and limitations of these tools for (1) automating the image analysis and reporting process, (2) improving procedural planning, and (3) offering additional insight into post-TAVR outcomes. Finally, the direction of future research necessary to bridge these tools towards clinical integration is discussed. Recent Findings: Transcatheter aortic valve replacement (TAVR) has become a pivotal treatment option for select patients with severe aortic stenosis, and its indication for use continues to broaden. Noninvasive imaging techniques such as CTA and MRA have become routine for patient selection, preprocedural planning, and predicting the risk of complications. As the current methods for pre-TAVR image analysis are labor-intensive and have significant inter-operator variability, experts are looking towards artificial intelligence (AI) as a potential solution. Summary: AI has the potential to significantly enhance the planning, execution, and post-procedural follow up of TAVR. While AI tools are promising, the irreplaceable value of nuanced clinical judgment by skilled physician teams must not be overlooked. With continued research, collaboration, and careful implementation, AI can become an integral part in imaging for TAVR, ultimately improving patient care and outcomes

Effect of cross-platform variations on transthoracic echocardiography measurements and clinical diagnosis

AIMS: Accurate cardiac chamber quantification is essential for clinical decisions and ideally should be consistent across different echocardiography systems. This study evaluates variations between the Philips EPIQ CVx (version 9.0.3) and Canon Aplio i900 (version 7.0) in measuring cardiac volumes, ventricular function, and valve structures. METHODS AND RESULTS: In this gender-balanced, single-centre study, 40 healthy volunteers (20 females and 20 males) aged 40 years and older (mean age 56.75 ± 11.57 years) were scanned alternately with both systems by the same sonographer using identical settings for both 2D and 4D acquisitions. We compared left ventricular (LV) and right ventricular (RV) volumes using paired t-tests, with significance set at P < 0.05. Correlation and Bland-Altman plots were used for quantities showing significant differences. Two board-certified cardiologists evaluated valve anatomy for each platform. The results showed no significant differences in LV end-systolic volume and LV ejection fraction between platforms. However, LV end-diastolic volume (LVEDV) differed significantly (biplane: P = 0.018; 4D: P = 0.028). Right ventricular (RV) measurements in 4D showed no significant differences, but there were notable disparities in 2D and 4D volumes within each platform (P < 0.01). Significant differences were also found in the LV systolic dyssynchrony index (P = 0.03), LV longitudinal strain (P = 0.04), LV twist (P = 0.004), and LV torsion (P = 0.005). Valve structure assessments varied, with more abnormalities noted on the Philips platform. CONCLUSION: Although LV and RV volumetric measurements are generally comparable, significant differences in LVEDV, LV strain metrics, and 2D vs. 4D measurements exist. These variations should be considered when using different platforms for patient follow-ups

Artificial intelligence in pediatric and adult congenital cardiac MRI: an unmet clinical need.

Cardiac MRI (CMR) allows non-invasive, non-ionizing assessment of cardiac function and anatomy in patients with congenital heart disease (CHD). The utility of CMR as a non-invasive imaging tool for evaluation of CHD have been growing exponentially over the past decade. The algorithms based on artificial intelligence (AI), and in particular, deep learning, have rapidly become a methodology of choice for analyzing CMR. A wide range of applications for AI have been developed to tackle challenges in various aspects of CMR, and significant advances have also been made from image acquisition to image analysis and diagnosis. We include an overview of AI definitions, different architectures, and details on well-known methods. This paper reviews the major deep learning concepts used for analyses of patients with CHD. In the end, we have summarized a list of open challenges and concerns to be considered for future studies

A Model of Fluid-Structure and Biochemical Interactions for Applications to Subclinical Leaflet Thrombosis

Subclinical leaflet thrombosis (SLT) is a potentially serious complication of aortic valve replacement with a bioprosthetic valve in which blood clots form on the replacement valve. SLT is associated with increased risk of transient ischemic attacks and strokes and can progress to clinical leaflet thrombosis. SLT following aortic valve replacement also may be related to subsequent structural valve deterioration, which can impair the durability of the valve replacement. Because of the difficulty in clinical imaging of SLT, models are needed to determine the mechanisms of SLT and could eventually predict which patients will develop SLT. To this end, we develop methods to simulate leaflet thrombosis that combine fluid-structure interaction and a simplified thrombosis model that allows for deposition along the moving leaflets. Additionally, this model can be adapted to model deposition or absorption along other moving boundaries. We present convergence results and quantify the model's ability to realize changes in valve opening and pressures. These new approaches are an important advancement in our tools for modeling thrombosis in which they incorporate both adhesion to the surface of the moving leaflets and feedback to the fluid-structure interaction.Comment: 29 pages, 11 figure

Is the Lecompte technique the last word on transposition of the great arteries repair for all patients? A magnetic resonance imaging study including a spiral technique two decades postoperatively.

ObjectivesTo compare the Lecompte technique and the spiral anastomosis (complete anatomic correction) two decades after arterial switch operation (ASO).MethodsNine patients after primary ASO with Lecompte and 6 selected patients after spiral anastomosis were evaluated 20.8 ± 2.1 years after ASO versus matched controls. Blood flow dynamics and flow profiles (e.g. vorticity, helicity) in the great arteries were quantified from time-resolved 3D magnetic resonance imaging (MRI) phase contrast flow measurements (4D flow MR) in addition to a comprehensive anatomical and functional cardiovascular MRI analysis.ResultsCompared with spiral reconstruction, patients with Lecompte showed more vortex formation, supranatural helical blood flow (relative helicity in aorta: 0.036 vs 0.089; P < 0.01), a reduced indexed cross-sectional area of the left pulmonary artery (155 vs 85 mm²/m²; P < 0.001) and more semilunar valve dysfunctions (n = 5 vs 1). There was no difference in elastic aortic wall properties, ventricular function, myocardial perfusion and myocardial fibrosis between the two groups. Cross-sectional area of the aortic sinus was larger in patients than in controls (669 vs 411 mm²/m²; P < 0.01). In the spiral group, the pulmonary root was rotated after ASO more towards the normal left position (P < 0.01).ConclusionsIn this study, selected patients with spiral anastomoses showed, two decades after ASO, better physiologically adapted blood flow dynamics, and attained a closer to normal anatomical position of their great arteries, as well as less valve dysfunction. Considering the limitations related to the small number of patients and the novel MRI imaging techniques, these data may provoke reconsidering the optimal surgical approaches to transposition of the great arteries repair